Patent Publication Number: US-8113115-B2

Title: Liquid transfer member pressing force adjusting method and apparatus of rotary stencil printing plate liquid coating machine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a liquid transfer member pressing force adjusting method and apparatus of a rotary stencil printing plate liquid coating machine such as a rotary screen printing press. In the descriptions to follow, examples, in which a rotary screen printing press is used as a rotary stencil printing plate liquid coating machine, and ink is used as a liquid to be coated on a material to be liquid coated, will be explained to facilitate understanding. It goes without saying, however, that the present invention is similarly applied to a liquid coating machine using a stencil printing plate put to other uses instead of the rotary screen printing press, the liquid coating machine using a rotary screen coater for coating varnish in place of ink. Furthermore, the examples using a machine for coating the liquid on a sheet as the rotary stencil printing plate liquid coating machine will be explained. Needless to say, however, the present invention is similarly applied to a machine for coating the liquid on a web. If the liquid is coated on the web, a pressing roll without a notch for accommodating a gripper is used as a pressing body opposing a stencil printing plate cylinder, instead of an impression cylinder to be described below. 
     2. Description of the Related Art 
     A rotary screen printing press equipped with a squeegee or a doctor roller (ink transfer member=liquid transfer member), which is located within a rotary screen cylinder (stencil printing plate cylinder) and, during printing (liquid coating), is brought into contact with the inner peripheral surface of a screen printing forme (stencil printing plate), while being pressed against it, to transfer ink (liquid) stored within the rotary screen cylinder to a material to be printed (material to be liquid coated) supplied between the rotary screen cylinder and an impression cylinder through the holes of the screen printing forme, is generally well known. 
     With the conventional rotary screen printing press described above, an operator manually adjusts the pressing force of the squeegee or doctor roller acting on the inner peripheral surface of the screen printing forme in the rotary screen cylinder while printing. 
     Thus, the operator is burdened, and time is taken until normal printing products can be obtained by printing. Consequently, the rate of operation decreases and, during this process, a large amount of wasted paper occurs. 
     The present invention has been accomplished in light of the above-described problems. It is an object of the invention to provide a liquid transfer member pressing force adjusting method and apparatus of a rotary stencil printing plate liquid coating machine, which can lessen burden on the operator, increase the rate of operation, and curtail the occurrence of wasted paper. 
     SUMMARY OF THE INVENTION 
     A first aspect of the present invention is a liquid transfer member pressing force adjusting method of a rotary stencil printing plate liquid coating machine including, 
     a stencil printing plate cylinder which supports a stencil printing plate and is supported rotatably, 
     a pressing body which is provided to oppose the stencil printing plate cylinder, and is supported rotatably, and 
     a liquid transfer member which is located within the stencil printing plate cylinder and, during liquid coating, contacts an inner peripheral surface of the stencil printing plate, while being pressed against the inner peripheral surface of the stencil printing plate, to transfer a liquid stored within the stencil printing plate cylinder to a material to be liquid coated, which is supplied between the stencil printing plate cylinder and the pressing body, via holes of the stencil printing plate, 
     wherein a pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating is obtained from a type and a thickness of the material to be liquid coated. 
     The pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating may be obtained from a type of the stencil printing plate. 
     The pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating may be obtained from a picture pattern area rate of a picture pattern to be applied by the liquid coating to the material to be liquid coated, and from a size of each of the holes of the stencil printing plate. 
     The pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating may be obtained from a type of the liquid used in the liquid coating. 
     The pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating may be obtained from a type of the liquid transfer member. 
     Adjustment of the pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate may be made by adjusting a position of the liquid transfer member. 
     Adjustment of the position of the liquid transfer member may be made by a motor. 
     A second aspect of the present invention is a liquid transfer member pressing force adjusting apparatus of a rotary stencil printing plate liquid coating machine including, 
     a stencil printing plate cylinder which supports a stencil printing plate and is supported rotatably, 
     a pressing body which is provided to oppose the stencil printing plate cylinder, and is supported rotatably, and 
     a liquid transfer member which is located within the stencil printing plate cylinder and, during liquid coating, contacts an inner peripheral surface of the stencil printing plate, while being pressed against the inner peripheral surface of the stencil printing plate, to transfer a liquid stored within the stencil printing plate cylinder to a material to be liquid coated, which is supplied between the stencil printing plate cylinder and the pressing body, via holes of the stencil printing plate, 
     the liquid transfer member pressing force adjusting apparatus comprising control means which controls a pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate during the liquid coating in accordance with a type and a thickness of the material to be liquid coated. 
     The control means may control the pressing force of the liquid transfer member, which acts on the inner peripheral surface of the stencil printing plate during the liquid coating, in accordance with a type of the stencil printing plate. 
     The control means may control the pressing force of the liquid transfer member, which acts on the inner peripheral surface of the stencil printing plate during the liquid coating, in accordance with a picture pattern area rate of a picture pattern to be applied by the liquid coating to the material to be liquid coated, and in accordance with a size of each of the holes of the stencil printing plate. 
     The control means may control the pressing force of the liquid transfer member, which acts on the inner peripheral surface of the stencil printing plate during the liquid coating, in accordance with a type of the liquid used in the liquid coating. 
     The control means may control the pressing force of the liquid transfer member, which acts on the inner peripheral surface of the stencil printing plate during the liquid coating, in accordance with a type of the liquid transfer member. 
     The control means may make adjustment of the pressing force of the liquid transfer member acting on the inner peripheral surface of the stencil printing plate by controlling a position of the liquid transfer member. 
     The control means may make adjustment of the position of the liquid transfer member by drivingly controlling a motor. 
     According to the features of the present invention, the position of the liquid transfer member during liquid coating can be preset, in conformity with the type of the material to be liquid coated (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), the thickness of the material to be liquid coated, the type of the stencil printing plate, the picture pattern area rate of the picture pattern to be applied by liquid coating to the material to be liquid coated and the size of each hole of the stencil printing plate, the type of the liquid, and the type of the liquid transfer member. Thus, burden on the operator can be lessened by automation, and the rate of operation can be increased and the occurrence of wasted paper can be curtailed by shortening the period of time until normally liquid coated materials can be obtained by liquid coating. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 1 of the present invention; 
         FIG. 2  is a right side view of the rotary screen printing unit in  FIG. 1 ; 
         FIG. 3  is a left side view of the rotary screen printing unit in  FIG. 1 ; 
         FIG. 4(   a ) is an operating state view; 
         FIG. 4(   b ) is an operating state view; 
         FIG. 5(   a ) is a control block diagram of a squeegee throw-on and throw-off control device; 
         FIG. 5(   b ) is a control block diagram of the squeegee throw-on and throw-off control device; 
         FIG. 5(   c ) is a control block diagram of the squeegee throw-on and throw-off control device; 
         FIG. 6(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 6(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 6(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 6(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 6(   e ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 7(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 7(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 7(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 7(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 8(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 8(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 8(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 8(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 9(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 9(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 9(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 9(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 10(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 10(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 10(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 10(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 11(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 11(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 11(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 11(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 12(   a ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 12(   b ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 12(   c ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 12(   d ) is a motion flow chart of the squeegee throw-on and throw-off control device; 
         FIG. 13  is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 2 of the present invention; 
         FIG. 14(   a ) is an explanation drawing of an ink supply system; 
         FIG. 14(   b ) is an explanation drawing of an ink supply pipe; 
         FIG. 15(   a ) is a control block diagram of a doctor roller throw-on and throw-off control device; 
         FIG. 15(   b ) is a control block diagram of the doctor roller throw-on and throw-off control device; 
         FIG. 15(   c ) is a control block diagram of the doctor roller throw-on and throw-off control device; 
         FIG. 16(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 16(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 16(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 16(   d ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 16(   e ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 17(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 17(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 17(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 17(   d ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 18(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 18(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 18(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 19(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 19(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 19(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 20(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 20(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 20(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 21(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 21(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 21(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 22(   a ) is a motion flow chart of the doctor roller throw-on and throw-off control device; 
         FIG. 22(   b ) is a motion flow chart of the doctor roller throw-on and throw-off control device; and 
         FIG. 22(   c ) is a motion flow chart of the doctor roller throw-on and throw-off control device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The liquid transfer member pressing force adjusting method and apparatus of a rotary stencil printing plate liquid coating machine according to the present invention will be described in detail by embodiments of the invention by reference to the accompanying drawings. 
     Embodiment 1 
       FIG. 1  is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 1 of the present invention.  FIG. 2  is a right side view of the rotary screen printing unit in  FIG. 1 .  FIG. 3  is a left side view of the rotary screen printing unit in  FIG. 1 .  FIGS. 4(   a ) and  4 ( b ) are operating state views.  FIGS. 5(   a ) to  5 ( c ) are control block diagrams of a squeegee throw-on and throw-off control device.  FIGS. 6(   a ) to  6 ( e ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 7(   a ) to  7 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 8(   a ) to  8 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 9(   a ) to  9 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 10(   a ) to  10 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 11(   a ) to  11 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device.  FIGS. 12(   a ) to  12 ( d ) are motion flow charts of the squeegee throw-on and throw-off control device. 
     In the rotary screen printing unit in the rotary screen printing press (rotary stencil printing press=rotary stencil printing plate liquid coating machine), as shown in  FIG. 1 , a rotary screen cylinder (stencil printing plate cylinder)  11  is supported between right and left frames  10  via eccentric bearings  12  to be capable of being thrown on and thrown off an impression cylinder (pressing body)  13 . The right and left eccentric bearings  12  are supported by the right and left frames  10  to be pivotable and slidable in a lateral direction (axial direction). 
     The impression cylinder  13  has notches (concavities)  13   b  provided in an outer peripheral surface thereof, each notch  13   b  accommodating a gripper device (a device for holding a material to be printed)  13   a  for holding a material to be printed (a material to be liquid coated), W, such as a sheet, as shown in  FIGS. 4(   a ) and  4 ( b ). In the illustrated embodiment, two of the notches  13   b  are provided at positions symmetrical with respect to the central point of the impression cylinder  13 , but this is not limitative. 
     The rotary screen cylinder  11  has a cylindrical screen printing forme (stencil printing plate)  11   c  supported between right and left tubular end members  11   a  via intermediate members  11   b . Also, the rotary screen cylinder  11  is supported by bearings  14  at small-diameter portions of the right and left tubular end members  11   a  to be rotatable with respect to the eccentric bearings  12 . 
     A gear  15  is located at, and secured to, an end part of the small-diameter portion of the right tubular end member  11   a , and a gear  17  secured onto an output shaft of a motor  16  meshes with the gear  15 . The motor  16  is mounted on a subframe  18  bound to the right frame  10 . 
     Thus, the rotary screen cylinder  11  can be rotationally driven and circumferentially registered by the motor  16  via the above-mentioned gear mechanism. 
     One end of a link  19  is pinned to each of the right and left eccentric bearings  12 , and the leading end of a lever  20  is pinned to the other end of the link  19 . Proximal end portions of the right and left levers  20  are secured to right and left end portions of a rotating shaft  21  journaled between the right and left frames  10 . A leading end of an actuator  22  is pinned to the left lever  20 . 
     Hence, the eccentric bearing  12  is pivoted by the actuator  22  via the above-mentioned link mechanism, whereby the rotary screen cylinder  11  is eccentrically rotated to be capable of being thrown on and thrown off the impression cylinder  13  (see  FIG. 4(   a ) and  FIG. 4(   b )). 
     An elongated hole, which is formed in a flange portion  12   a  of each of the right and left eccentric bearings  12 , is fitted with a head  23   a  of a bolt  23  such that the head  23   a  is rotatable, and movable in the direction of the major diameter of the elongated hole, but immovable in the axial direction. On the other hand, a threaded portion  23   b  of the bolt  23  is fitted into a tapped hole of the frame  10 . A gear  24   a  is secured to the head  23   a  of each of the right and left bolts  23 , and a gear  24   b  secured onto an output shaft of a motor  25  meshes with the gear  24   a . The right and left motors  25  are mounted on support brackets  26  bound to the right and left frames  10 . 
     Thus, the right and left eccentric bearings  12  are slid in the lateral direction (axial direction) by the motors  25  via the aforementioned gear mechanism and feed screw mechanism to make possible the tension adjustment of the screen printing forme  11   c  and the movement of the bearing at the time of rotary screen cylinder removal. 
     As shown in  FIGS. 2 and 3  as well, a pipe-shaped support shaft  27  closed at the right end is inserted through the interior of the rotary screen cylinder  11 . The right end side of the support shaft  27  is fitted into, and supported by, a fitting hole  28   a  of a bearing member  28 , which is located outwardly and laterally of the subframe  18 , in such a manner as to be turnable and movable (slidable) in the lateral direction (axial direction), while the left end side of the support shaft  27  is fitted into, and supported by, a bearing member  29 , which is located outwardly and laterally of the left frame  10 , in such a manner as not to be turnable and movable (slidable) in the lateral direction (axial direction). 
     That is, the left end side of the support shaft  27  is inhibited from moving (sliding) in the lateral direction (axial direction) by stepped portions  27   a  and  27   b  at two (right and left) locations, and is also inhibited from turning because it is pressed from above by a holding plate  30   a  while being accommodated within a fitting groove  29   a  of the bearing member  29  having a groove bottom formed in a taper shape. 
     The holding plate  30   a  horizontally rotates about a fulcrum pin  31   a , and can thus open and close the fitting groove  29   a . With the fitting groove  29   a  being closed, a fixing lever  30   b  is screwed into the holding plate  30   a  and the bearing member  29 , whereby the closed state is retained. 
     The right and left bearing members  28  and  29  are supported movably in a vertical direction via ball screws  32  by support cases  31  annexed to the frame  10  and the subframe  18 . Concretely, a nut member  32   a  of the ball screw  32  is secured to the interior of the support case  31 , and a screw member  32   b  screwed to the nut member  32   a  penetrates the interior of the support case  31  in a vertical direction. A non-screw-forming shaft portion of the screw member  32   b  is supported pivotably and slidably within the support case  31  via a bearing  33 . 
     An upper end portion of the screw member  32   b  is engaged with an engaging hole  28   b  or  29   b  of the bearing member  28  or  29  via a spherical bearing  34  to permit the rotation of the screw member  32   b  and the inclination of the support shaft  27  during position adjustment (to be described later) of the support shaft  27 . A gear  35   a  is secured to a lower end portion of the screw member  32   b , and a gear  35   b  secured onto an output shaft of a motor  36 A or  36 B meshes with the gear  35   a . The motor  36 A for adjusting the left side is mounted on an outer surface of the frame  10 , and the motor  36 B for adjusting the right side is mounted on an outer surface of the subframe  18 . 
     In  FIG. 1 , reference numeral  39  denotes a whirl-stop pin for positioning of the bearing member  28  or  29  in the absence of the support shaft  27 , and for positioning, in the longitudinal direction, of the support shaft  27 . 
     A rubber squeegee (ink transfer member=liquid transfer member)  38  is supported on the support shaft  27  via a holder  37 , as shown in  FIGS. 4(   a ) and  4 ( b ). A leading end of the squeegee  38  makes a sliding contact with the inner peripheral surface of the screen printing forme  11   c , with the result that ink (liquid) supplied into the screen printing forme  11   c  through the interior of the support shaft  27  is transferred onto a printing surface of the material to be printed, W, via holes of the screen printing forme  11   c.    
     In the present Embodiment 1, the motors  36 A and  36 B are drivingly controlled, independently of each other, by a squeegee throw-on and throw-off control device (control means)  40 A to be described later, whereby throw-on and throw-off of the squeegee  38  with respect to the inner peripheral surface of the screen printing forme  11   c , and the adjustment of the throw-on position of the squeegee  38  are automatically carried out. 
     The squeegee throw-on and throw-off control device  40 A can preset the throw-on position of the squeegee  38  during printing (liquid coating), based on the type of the material W to be printed (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), in accordance with the thickness of the material to be printed, the material for the screen printing forme  11   c , the thickness of the screen printing forme, the picture pattern area rate, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the squeegee, and the thickness of the squeegee. Concretely, relevant motions will be described by motion flow charts to be offered later. 
     The squeegee throw-on and throw-off control device  40 A comprises CPU  41 , RAM  42 , ROM  43 , input/output devices  44  to  50 , and an interface  51  connected together by BUS (bus line), as shown in  FIGS. 5(   a ) to  5 ( c ). To the BUS (bus line), the following memories are connected: A memory M 1  for storing the type of the material to be printed, a memory M 2  for storing the thickness of the material to be printed, a memory M 3  for storing the material for the screen printing forme, a memory M 4  for storing the thickness of the screen printing forme, a memory M 5  for storing the picture pattern area rate, a memory M 6  for storing the mesh size of the screen printing forme, a memory M 7  for storing the viscosity of ink, a memory M 8  for storing the yield value of ink, a memory M 9  for storing the type of a pigment of ink, a memory M 10  for storing the material for the squeegee, and a memory M 11  for storing the thickness of the squeegee. 
     To the BUS (bus line), the following memories are further connected: A memory M 12  for storing a table of conversion from the type of the material to be printed to the throw-on position (count value of a counter) of the squeegee, a memory M 13  for storing the provisional reference throw-on position (count value of the counter) of the squeegee, a memory M 14  for storing a table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the squeegee, a memory M 15  for storing the first correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 16  for storing a table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the squeegee, a memory M 17  for storing the second correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 18  for storing a table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, a memory M 19  for storing the third correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 20  for storing a table of conversion from the picture pattern area rate to the throw-on position (count value of the counter) of the squeegee, and a memory M 21  for storing the fourth correction value (count value of the counter) of the throw-on position of the squeegee. 
     To the BUS (bus line), the following memories are further connected: A memory M 22  for storing a table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, a memory M 23  for storing the fifth correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 24  for storing a table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the squeegee, a memory M 25  for storing the sixth correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 26  for storing a table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the squeegee, a memory M 27  for storing the seventh correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 28  for storing a table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the squeegee, a memory M 29  for storing the eighth correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 30  for storing a table of conversion from the material for the squeegee to the throw-on position (count value of the counter) of the squeegee, a memory M 31  for storing the ninth correction value (count value of the counter) of the throw-on position of the squeegee, a memory M 32  for storing a table of conversion from the thickness of the squeegee to the throw-on position (count value of the counter) of the squeegee, and a memory M 33  for storing the tenth correction value (count value of the counter) of the throw-on position of the squeegee. 
     To the BUS (bus line), the following memories are further connected: A memory M 34  for storing the reference throw-on position (count value of the counter) of the squeegee, a memory M 35  for storing a table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the squeegee, a memory M 36  for storing the provisional reference retreat position (count value of the counter) of the squeegee, a memory M 37  for storing a table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the squeegee, a memory M 38  for storing the first correction value (count value of the counter) of the retreat position of the squeegee, a memory M 39  for storing a table of conversion from the picture pattern area rate to the retreat position (count value of the counter) of the squeegee, a memory M 40  for storing the second correction value (count value of the counter) of the retreat position of the squeegee, a memory M 41  for storing a table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the squeegee, a memory M 42  for storing the third correction value (count value of the counter) of the retreat position of the squeegee, a memory M 43  for storing a table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the squeegee, a memory M 44  for storing the fourth correction value (count value of the counter) of the retreat position of the squeegee, a memory M 45  for storing a table of conversion from the yield value of ink to the retreat position (count value of the counter) of the squeegee, and a memory M 46  for storing the fifth correction value (count value of the counter) of the retreat position of the squeegee. 
     To the BUS (bus line), the following memories are further connected: A memory M 47  for storing a table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the squeegee, a memory M 48  for storing the sixth correction value (count value of the counter) of the retreat position of the squeegee, a memory M 49  for storing a table of conversion from the material for the squeegee to the retreat position (count value of the counter) of the squeegee, a memory M 50  for storing the seventh correction value (count value of the counter) of the retreat position of the squeegee, a memory M 51  for storing a table of conversion from the thickness of the squeegee to the retreat position (count value of the counter) of the squeegee, a memory M 52  for storing the eighth correction value (count value of the counter) of the retreat position of the squeegee, a memory M 53  for storing the reference retreat position (count value of the counter) of the squeegee, a memory M 54  for storing the throw-off position (count value of the counter) of the squeegee, a memory M 55  for storing the desired count value of a counter for detecting the position of the left side of the squeegee, a memory M 56  for storing the desired count value of a counter for detecting the position of the right side of the squeegee, a memory M 57  for storing the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder, and a memory M 58  for storing the rotation phase of the rotary screen cylinder during squeegee throw-off. 
     To the BUS (bus line), the following memories are further connected: A memory M 59  for storing the count value S, a memory M 60  for storing the rotating direction of the motor for adjusting the left side, a memory M 61  for storing the rotating direction of the motor for adjusting the right side, a memory M 62  for storing the count value of a counter for detecting the current position of the left side of the squeegee, a memory M 63  for storing the count value of a counter for detecting the current position of the right side of the squeegee, a memory M 64  for storing a table of conversion from the total number of revolutions during squeegee throw-on to the correction amount (count value of the counter) of the squeegee position, a memory M 65  for storing the count value of a counter for counting the total number of revolutions during squeegee throw-on, a memory M 66  for storing the correction amount (count value of the counter) of the squeegee position, a memory M 67  for storing the retreat position (count value of the counter) of the squeegee, a memory M 68  for storing the count value of a counter for detecting the rotation phase of the rotary screen cylinder, a memory M 69  for storing the rotation phase of the rotary screen cylinder during squeegee throw-on, a memory M 70  for storing the printing position (count value of the counter) of the squeegee, and a memory M 71  for storing the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder. 
     To the input/output device  44 , the following are connected: A squeegee throw-on and throw-off automatic control switch  52 , an input device  53  such as a keyboard, a display device  54  such as CRT or a display, and an output device  55  such as a printer or a floppy disk (registered trademark) drive. 
     To the input/output device  45 , the following are connected: A setting instrument  56  for the type of the material to be printed, a setting instrument  57  for the thickness of the material to be printed, a setting instrument  58  for the material for the screen printing forme, a setting instrument  59  for the thickness of the screen printing forme, a setting instrument  60  for the mesh size of the screen printing forme, a setting instrument  61  for the viscosity of ink, a setting instrument  62  for the yield value of ink, a setting instrument  63  for the type of the pigment of ink, a setting instrument  64  for the material for the squeegee, and a setting instrument  65  for the thickness of the squeegee. 
     To the input/output device  46 , the motor  36 A for adjusting the left side is connected via a driver  66  for the motor for adjusting the left side, and a rotary encoder  69  for the motor for adjusting the left side which is drivingly connected to the motor  36 A is connected via a counter  68  for detecting the current position of the left side of the squeegee. 
     To the input/output device  47 , the motor  36 B for adjusting the right side is connected via a driver  70  for the motor for adjusting the right side, and a rotary encoder  73  for the motor for adjusting the right side which is drivingly connected to the motor  36 B is connected via a counter  72  for detecting the current position of the right side of the squeegee. 
     To the input/output device  48 , a rotary encoder  75  for detecting the rotation phase of the rotary screen cylinder is connected via a counter  74  for detecting the rotation phase of the rotary screen cylinder. The rotary encoder  75  for detecting the rotation phase of the rotary screen cylinder is provided on a rotating part of the rotary screen printing press rotating in synchronism with the rotary screen cylinder in such a manner as to generate a zero pulse in the reference rotation phase of the rotary screen cylinder. Thus, the counter  74  for detecting the rotation phase of the rotary screen cylinder is reset in the reference rotation phase of the rotary screen cylinder each time the rotary screen cylinder makes one rotation. Then, the counter  74  for detecting the rotation phase of the rotary screen cylinder counts clock pulses generated in accordance with the rotation of the rotary screen cylinder, producing a count value conformed to the rotation phase of the rotary screen cylinder. 
     To the input/output device  49 , a sensor  77  for detecting one rotation of the rotary screen cylinder is connected via a counter  76  for counting the total number of revolutions during squeegee throw-on. The sensor  77  for detecting one rotation of the rotary screen cylinder is provided on a rotating part of the rotary screen printing press so as to produce one pulse each time the rotary screen cylinder makes one rotation. Thus, the counter  76  for counting the total number of revolutions during squeegee throw-on is adapted to count the number of revolutions of the rotary screen cylinder in an operating state. 
     To the input/output device  50 , a cylinder engagement circuit  78  for the rotary screen cylinder is connected. 
     To the interface  51 , a picture pattern area rate measuring device  79  for measuring the picture pattern area rate of the picture pattern to be printed on the material W to be printed is connected. The picture pattern area rate measuring device  79  used is a publicly known one, for example, that which images the picture pattern surface of the screen printing forme  11   c  by a TV camera having solid photoelectric conversion elements arranged in a matrix form, and measures the picture pattern area rate. 
     The control actions or motions of the squeegee throw-on and throw-off control device  40 A configured as above will be described in detail based on the motion flow charts of  FIGS. 6(   a ) to  6 ( e ),  FIGS. 7(   a ) to  7 ( d ),  FIGS. 8(   a ) to  8 ( d ),  FIGS. 9(   a ) to  9 ( d ),  FIGS. 10(   a ) to  10 ( d ),  FIGS. 11(   a ) to  11 ( d ), and  FIGS. 12(   a ) to  12 ( d ). 
     In Step P 1 , it is determined whether there is an input to the setting instrument  56  for the type of the material to be printed. If the answer is Y (yes), the type of the material W to be printed is loaded from the setting instrument  56  for the type of the material to be printed, and stored into the memory M 1 , in Step P 2 , and the program proceeds to Step P 3 . If the answer is N (no), the program directly shifts to Step P 3 . 
     Then, in Step P 3 , it is determined whether there is an input to the setting instrument  57  for the thickness of the material to be printed. If the answer is Y, the thickness of the material to be printed is loaded from the setting instrument  57  for the thickness of the material to be printed, and stored into the memory M 2 , in Step P 4 . Then, the program proceeds to Step P 5 . If the answer is N, the program directly shifts to Step P 5 . 
     Then, in Step P 5 , it is determined whether there is an input to the setting instrument  58  for the material for the screen printing forme. If the answer is Y, the material for the screen printing forme  11   c  is loaded from the setting instrument  58  for the material for the screen printing forme, and stored into the memory M 3 , in Step P 6 . Then, the program proceeds to Step P 7 . If the answer is N, the program directly shifts to Step P 7 . 
     Then, in Step P 7 , it is determined whether there is an input to the setting instrument  59  for the thickness of the screen printing forme. If the answer is Y, the thickness of the screen printing forme is loaded from the setting instrument  59  for the thickness of the screen printing forme, and stored into the memory M 4 , in Step P 8 . Then, the program proceeds to Step P 9 . If the answer is N, the program directly shifts to Step P 9 . 
     Then, in Step P 9 , it is determined whether the picture pattern area rate has been transmitted from the picture pattern area rate measuring device  79 . If the answer is Y, the picture pattern area rate is received from the picture pattern area rate measuring device  79 , and stored into the memory M 5 , in Step P 10 . Then, the program proceeds to Step P 11 . If the answer is N, the program directly shifts to Step P 11 . 
     Then, in Step P 11 , it is determined whether there is an input to the setting instrument  60  for the mesh size of the screen printing forme. If the answer is Y, the mesh size of the screen printing forme  11   c  is loaded from the setting instrument  60  for the mesh size of the screen printing forme, and stored into the memory M 6 , in Step P 12 . Then, the program proceeds to Step P 13 . If the answer is N, the program directly shifts to Step P 13 . 
     Then, in Step P 13 , it is determined whether there is an input to the setting instrument  61  for the viscosity of ink. If the answer is Y, the viscosity of ink is loaded from the setting instrument  61  for the viscosity of ink, and stored into the memory M 7 , in Step P 14 . Then, the program proceeds to Step P 15 . If the answer is N, the program directly shifts to Step P 15 . 
     Then, in Step P 15 , it is determined whether there is an input to the setting instrument  62  for the yield value of ink. If the answer is Y, the yield value of ink is loaded from the setting instrument  62  for the yield value of ink, and stored into the memory M 8 , in Step P 16 . Then, the program proceeds to Step P 17 . If the answer is N, the program directly shifts to Step P 17 . 
     Then, in Step P 17 , it is determined whether there is an input to the setting instrument  63  for the type of the pigment of ink. If the answer is Y, the type of the pigment of ink is loaded from the setting instrument  63  for the type of the pigment of ink, and stored into the memory M 9 , in Step P 18 . Then, the program proceeds to Step P 19 . If the answer is N, the program directly shifts to Step P 19 . 
     Then, in Step P 19 , it is determined whether there is an input to the setting instrument  64  for the material for the squeegee. If the answer is Y, the material for the squeegee  38  is loaded from the setting instrument  64  for the material for the squeegee, and stored into the memory M 10 , in Step P 20 . Then, the program proceeds to Step P 21 . If the answer is N, the program directly shifts to Step P 21 . 
     Then, in Step P 21 , it is determined whether there is an input to the setting instrument  65  for the thickness of the squeegee. If the answer is Y, the thickness of the squeegee is loaded from the setting instrument  65  for the thickness of the squeegee, and stored into the memory M 11 , in Step P 22 . Then, the program proceeds to Step P 23 . If the answer is N, the program directly shifts to Step P 23 . 
     Then, in Step P 23 , it is determined whether the squeegee throw-on and throw-off automatic control switch  52  is ON. If the answer is Y, the table of conversion from the type of the material to be printed to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 12  in Step P 24 . If the answer is N, the program returns to Step P 1 . 
     Then, in Step P 25 , the type of the material W to be printed is loaded from the memory M 1 . Then, in Step P 26 , the provisional reference throw-on position (count value of the counter) of the squeegee is obtained from the type of the material W to be printed, with the use of the table of conversion from the type of the material to be printed to the throw-on position (count value of the counter) of the squeegee, and is stored into the memory M 13 . 
     Then, in Step P 27 , the type of the material W to be printed is loaded from the memory M 1 . Then, in Step P 28 , the table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the type of the material to be printed, is loaded from the memory M 14 . 
     Then, in Step P 29 , the thickness of the material to be printed is loaded from the memory M 2 . Then, in Step P 30 , the first correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the thickness of the material to be printed, with the use of the table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the type of the material to be printed, and this correction value is stored into the memory M 15 . 
     Then, in Step P 31 , the table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 16 . Then, in Step P 32 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 33 , the second correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the material for the screen printing forme  11   c , with the use of the table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 17 . 
     Then, in Step P 34 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 35 , the table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme, is loaded from the memory M 18 . 
     Then, in Step P 36 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 37 , the third correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the thickness of the screen printing forme, with the use of the table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme, and this correction value is stored into the memory M 19 . 
     Then, in Step P 38 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 39 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 40 , the table of conversion from the picture pattern area rate to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 20 . 
     Then, in Step P 41 , the picture pattern area rate is loaded from the memory M 5 . Then, in Step P 42 , the fourth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the picture pattern area rate, with the use of the table of conversion from the picture pattern area rate to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 21 . 
     Then, in Step P 43 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 44 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 45 , the table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 22 . 
     Then, in Step P 46 , the mesh size of the screen printing forme is loaded from the memory M 6 . Then, in Step P 47 , the fifth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the mesh size of the screen printing forme, with the use of the table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 23 . 
     Then, in Step P 48 , the table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 24 . Then, in Step P 49 , the viscosity of ink is loaded from the memory M 7 . Then, in Step P 50 , the sixth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the viscosity of ink with the use of the table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 25 . 
     Then, in Step P 51 , the table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 26 . Then, in Step P 52 , the yield value of ink is loaded from the memory M 8 . Then, in Step P 53 , the seventh correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the yield value of ink with the use of the table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 27 . 
     Then, in Step P 54 , the table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 28 . Then, in Step P 55 , the type of the pigment of ink is loaded from the memory M 9 . Then, in Step P 56 , the eighth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the type of the pigment of ink with the use of the table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 29 . 
     Then, in Step P 57 , the table of conversion from the material for the squeegee to the throw-on position (count value of the counter) of the squeegee is loaded from the memory M 30 . Then, in Step P 58 , the material for the squeegee  38  is loaded from the memory M 10 . Then, in Step P 59 , the ninth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the material for the squeegee  38  with the use of the table of conversion from the material for the squeegee to the throw-on position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 31 . 
     Then, in Step P 60 , the material for the squeegee  38  is loaded from the memory M 10 . Then, in Step P 61 , the table of conversion from the thickness of the squeegee to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the squeegee, is loaded from the memory M 32 . 
     Then, in Step P 62 , the thickness of the squeegee is loaded from the memory M 11 . Then, in Step P 63 , the tenth correction value (count value of the counter) of the throw-on position of the squeegee is obtained from the thickness of the squeegee with the use of the table of conversion from the thickness of the squeegee to the throw-on position (count value of the counter) of the squeegee, which is commensurate with the material for the squeegee, and this correction value is stored into the memory M 33 . 
     Then, in Step P 64 , the provisional reference throw-on position (count value of the counter) of the squeegee is loaded from the memory M 13 , whereafter, in Step P 65 , the first correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 15 . Then, in Step P 66 , the second correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 17 . 
     Then, in Step P 67 , the third correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 19 , whereafter, in Step P 68 , the fourth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 21 . Then, in Step P 69 , the fifth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 23 . 
     Then, in Step P 70 , the sixth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 25 , whereafter, in Step P 71 , the seventh correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 27 . Then, in Step P 72 , the eighth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 29 . 
     Then, in Step P 73 , the ninth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 31 , whereafter, in Step P 74 , the tenth correction value (count value of the counter) of the throw-on position of the squeegee is loaded from the memory M 33 . 
     Then, in Step P 75 , the first correction value (count value of the counter) of the throw-on position of the squeegee, the second correction value (count value of the counter) of the throw-on position of the squeegee, the third correction value (count value of the counter) of the throw-on position of the squeegee, the fourth correction value (count value of the counter) of the throw-on position of the squeegee, the fifth correction value (count value of the counter) of the throw-on position of the squeegee, the sixth correction value (count value of the counter) of the throw-on position of the squeegee, the seventh correction value (count value of the counter) of the throw-on position of the squeegee, the eighth correction value (count value of the counter) of the throw-on position of the squeegee, the ninth correction value (count value of the counter) of the throw-on position of the squeegee, and the tenth correction value (count value of the counter) of the throw-on position of the squeegee are added to the provisional reference throw-on position (count value of the counter) of the squeegee to compute the reference throw-on position (count value of the counter) of the squeegee, and this reference throw-on position (count value of the counter) of the squeegee is stored into the memory M 34 . 
     In accordance with the above-described motion flow, the throw-on position of the squeegee  38  during printing is preset, based on the type of the material W to be printed (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), in conformity with the thickness of the material to be printed, the material for the screen printing forme  11   c , the thickness of the screen printing forme, the picture pattern area rate, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the squeegee, and the thickness of the squeegee. 
     Then, in Step P 76 , the table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the squeegee is loaded from the memory M 35 . Then, in Step P 77 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 78 , the provisional reference retreat position (count value of the counter) of the squeegee is obtained from the material for the screen printing forme  11   c  with the use of the table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the squeegee, and is stored into the memory M 36 . 
     Then, in Step P 79 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 80 , the table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme, is loaded from the memory M 37 . 
     Then, in Step P 81 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 82 , the first correction value (count value of the counter) of the retreat position of the squeegee is obtained from the thickness of the screen printing forme with the use of the table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme, and this correction value is stored into the memory M 38 . 
     Then, in Step P 83 , the material for the screen printing forme  11   c  is loaded from the memory M 3 , whereafter, in Step P 84 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 85 , the table of conversion from the picture pattern area rate to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 39 . 
     Then, in Step P 86 , the picture pattern area rate is loaded from the memory M 5 . Then, in Step P 87 , the second correction value (count value of the counter) of the retreat position of the squeegee is obtained from the picture pattern area rate with the use of the table of conversion from the picture pattern area rate to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 40 . 
     Then, in Step P 88 , the material for the screen printing forme is loaded from the memory M 3 . Then, in Step P 89 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 90 , the table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 41 . 
     Then, in Step P 91 , the mesh size of the screen printing forme  11   c  is loaded from the memory M 6 . Then, in Step P 92 , the third correction value (count value of the counter) of the retreat position of the squeegee is obtained from the mesh size of the screen printing forme  11   c  with the use of the table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 42 . 
     Then, in Step P 93 , the table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the squeegee is loaded from the memory M 43 . Then, in Step P 94 , the viscosity of ink is loaded from the memory M 7 . Then, in Step P 95 , the fourth correction value (count value of the counter) of the retreat position of the squeegee is obtained from the viscosity of ink with the use of the table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 44 . 
     Then, in Step P 96 , the table of conversion from the yield value of ink to the retreat position (count value of the counter) of the squeegee is loaded from the memory M 45 . Then, in Step P 97 , the yield value of ink is loaded from the memory M 8 . Then, in Step P 98 , the fifth correction value (count value of the counter) of the retreat position of the squeegee is obtained from the yield value of ink with the use of the table of conversion from the yield value of ink to the retreat position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 46 . 
     Then, in Step P 99 , the table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the squeegee is loaded from the memory M 47 . Then, in Step P 100 , the type of the pigment of ink is loaded from the memory M 9 . Then, in Step P 101 , the sixth correction value (count value of the counter) of the retreat position of the squeegee is obtained from the type of the pigment of ink with the use of the table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 48 . 
     Then, in Step P 102 , the table of conversion from the material for the squeegee to the retreat position (count value of the counter) of the squeegee is loaded from the memory M 49 . Then, in Step P 103 , the material for the squeegee is loaded from the memory M 10 . Then, in Step P 104 , the seventh correction value (count value of the counter) of the retreat position of the squeegee is obtained from the material for the squeegee with the use of the table of conversion from the material for the squeegee to the retreat position (count value of the counter) of the squeegee, and this correction value is stored into the memory M 50 . 
     Then, in Step P 105 , the material for the squeegee is loaded from the memory M 10 . Then, in Step P 106 , the table of conversion from the thickness of the squeegee to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the squeegee, is loaded from the memory M 51 . 
     Then, in Step P 107 , the thickness of the squeegee is loaded from the memory M 11 . Then, in Step P 108 , the eighth correction value (count value of the counter) of the retreat position of the squeegee is obtained from the thickness of the squeegee with the use of the table of conversion from the thickness of the squeegee to the retreat position (count value of the counter) of the squeegee, which is commensurate with the material for the squeegee, and this correction value is stored into the memory M 52 . 
     Then, in Step P 109 , the provisional reference retreat position (count value of the counter) of the squeegee is loaded from the memory M 36 , whereafter, in Step P 110 , the first correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 38 . Then, in Step P 111 , the second correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 40 . 
     Then, in Step P 112 , the third correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 42 , whereafter, in Step P 113 , the fourth correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 44 . Then, in Step P 114 , the fifth correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 46 . 
     Then, in Step P 115 , the sixth correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 48 , whereafter, in Step P 116 , the seventh correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 50 . Then, in Step P 117 , the eighth correction value (count value of the counter) of the retreat position of the squeegee is loaded from the memory M 52 . 
     Then, in Step P 118 , the first correction value (count value of the counter) of the retreat position of the squeegee, the second correction value (count value of the counter) of the retreat position of the squeegee, the third correction value (count value of the counter) of the retreat position of the squeegee, the fourth correction value (count value of the counter) of the retreat position of the squeegee, the fifth correction value (count value of the counter) of the retreat position of the squeegee, the sixth correction value (count value of the counter) of the retreat position of the squeegee, the seventh correction value (count value of the counter) of the retreat position of the squeegee, and the eighth correction value (count value of the counter) of the retreat position of the squeegee are added to the provisional reference retreat position (count value of the counter) of the squeegee to compute the reference retreat position (count value of the counter) of the squeegee, and this reference retreat position (count value of the counter) of the squeegee is stored into the memory M 53 . The reference retreat position (count value of the counter) of the squeegee obtained is a position closer to the throw-off position of the squeegee than to the reference throw-on position of the squeegee obtained in Step P 75 , in other words, a position at which the leading end of the squeegee  38  does not leave the inner peripheral surface of the screen printing forme  11   c , and its pressing force decreases. 
     In accordance with the above-described motion flow, the retreat position of the squeegee  38  when opposing the notch  13   b  of the impression cylinder  13  is preset, based on the material for the screen printing forme  11   c , in conformity with the thickness of the screen printing forme, the picture pattern area rate, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the squeegee, and the thickness of the squeegee. 
     Then, in Step P 119 , it is determined whether the squeegee throw-on and throw-off automatic control switch  52  is OFF. If the answer is Y (yes), the program shifts to Step P 351  to be described later. If the answer is N (no), it is determined, in Step P 120 , whether a cylinder engagement signal from the cylinder engagement circuit  78  for the rotary screen cylinder is ON. 
     If the answer is Y in the above Step P 120 , the program shifts to Step P 175  to be described later. If the answer is N, the throw-off position (count value of the counter) of the squeegee is loaded from the memory M 54  in Step P 121 . 
     Then, in Step P 122 , the memory M 55  for storing the desired count value of the counter for detecting the position of the left side of the squeegee is overwritten with the throw-off position (count value of the counter) of the squeegee. Then, in Step P 123 , the memory M 56  for storing the desired count value of the counter for detecting the position of the right side of the squeegee is overwritten with the throw-off position (count value of the counter) of the squeegee. 
     Then, in Step P 124 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 125 , the rotation phase of the rotary screen cylinder during squeegee throw-off is loaded from the memory M 58 . 
     Then, in Step P 126 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during squeegee throw-off. If the answer is N, the program returns to Step P 124  mentioned above. If the answer is Y, the count value S of the memory M 59  is overwritten with 0 in Step P 127 . 
     Then, in Step P 128 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 129 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 130 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 131 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 132 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is N, it is determined, in Step P 133 , whether the count value of the counter for detecting the current position of the left side of the squeegee is less than the desired count value of the counter for detecting the position of the left side of the squeegee. 
     If the answer is Y in the above Step P 133 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 1 in Step P 134 . Then, in Step P 135 , a normal rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program proceeds to Step P 136 . If the answer is N in Step P 133 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 2 in Step P 137 . Then, in Step P 138 , a reverse rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program shifts to Step P 136 . 
     If the answer is Y in the aforementioned Step P 132 , the count value S is loaded from the memory M 59 . Then, in Step P 140 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 136  mentioned above. 
     Then, in the aforementioned Step P 136 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 141 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 142 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is N, it is determined, in Step P 143 , whether the count value of the counter for detecting the current position of the right side of the squeegee is less than the desired count value of the counter for detecting the position of the right side of the squeegee. 
     If the answer is Y in the above Step P 143 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 1 in Step P 144 . Then, in Step P 145 , a normal rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program proceeds to Step P 146 . If the answer is N in Step P 143 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 2 in Step P 147 . Then, in Step P 148 , a reverse rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program shifts to Step P 146 . 
     If the answer is Y in the aforementioned Step P 142 , the count value S is loaded from the memory M 59  in Step P 149 . Then, in Step P 150 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 146  mentioned above. 
     Then, in Step P 146  mentioned above, the count value S is loaded from the memory M 59 , whereafter it is determined in Step P 151  whether the count value S is 2. If the answer is Y, outputting of the enabling signal to the counter  76  for counting the total number of revolutions during squeegee throw-on is stopped in Step P 152 , and the program returns to Step P 119  mentioned earlier. 
     Then, in Step P 153 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 154 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 155 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is Y, the value of the memory M 60  for storing the rotating direction of the motor for adjusting the left side is loaded in Step P 156 . If the answer is N, the program shifts to Step P 164  to be described later. 
     Then, in Step P 157 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 1. If the answer is Y, outputting of the normal rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 158 , and the program proceeds to Step P 159 . If the answer is N, it is determined in Step P 160  whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 2. 
     If the answer is Y in the above Step P 160 , outputting of the reverse rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 161 , and the program shifts to the aforementioned Step P 159 . If the answer is N, the program shifts to the aforementioned Step P 164 . 
     Then, in the above-mentioned Step P 159 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 162 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 163 . 
     Then, in Step P 164 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 165 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 166 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is Y, the value of the memory M 61  for storing the rotating direction of the motor for adjusting the right side is loaded in Step P 167 . If the answer is N, the program returns to Step P 146 . 
     Then, in Step P 168 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 1. If the answer is Y, outputting of the normal rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 169 , and the program proceeds to Step P 170 . If the answer is N, it is determined in Step P 171  whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 2. 
     If the answer is Y in the above Step P 171 , outputting of the reverse rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 172 , and the program shifts to the aforementioned Step P 170 . If the answer is N, the program returns to Step P 146 . 
     Then, in the aforementioned Step P 170 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. Then, in Step P 173 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 174 . Then, the program returns to Step P 146 . 
     In accordance with the above-described motion flow, when the squeegee throw-on and throw-off automatic control switch  52  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is OFF, the squeegee  38  is moved to the throw-off position. 
     Then, in Step P 175  shifted from the aforementioned Step P 120 , the table of conversion from the total number of revolutions during squeegee throw-onto the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 64 . Then, in Step P 176 , the count value is loaded from the counter  76  for counting the total number of revolutions during squeegee throw-on, and stored into the memory M 65 . 
     Then, in Step P 177 , the correction amount (count value of the counter) of the squeegee position is obtained from the count value of the counter  76  for counting the total number of revolutions during squeegee throw-on, with the use of the table of conversion from the total number of revolutions during squeegee throw-on to the correction amount (count value of the counter) of the squeegee position, and this correction amount is stored into the memory M 66 . Then, in Step P 178 , the reference retreat position (count value of the counter) of the squeegee is loaded from the memory M 53 . 
     Then, in Step P 179 , the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 66 . Then, in Step P 180 , the correction amount (count value of the counter) of the squeegee position is added to the reference retreat position (count value of the counter) of the squeegee to compute the retreat position (count value of the counter) of the squeegee, which is stored into the memory M 67 . 
     Then, in Step P 181 , the memory M 55  for storing the desired count value of the counter for detecting the position of the left side of the squeegee is overwritten with the retreat position (count value of the counter) of the squeegee. Then, in Step P 182 , the memory M 56  for storing the desired count value of the counter for detecting the position of the right side of the squeegee is overwritten with the retreat position (count value of the counter) of the squeegee. 
     Then, in Step P 183 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 184 , the rotation phase of the rotary screen cylinder during squeegee throw-on is loaded from the memory M 69 . 
     Then, in Step P 185 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during squeegee throw-on. If the answer is N, the program returns to Step P 183  mentioned above. If the answer is Y, the count value S of the memory M 59  is overwritten with 0 in Step P 186 . Then, in Step P 187 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 188 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 189 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 190 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 191 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is N, it is determined, in Step P 192 , whether the count value of the counter for detecting the current position of the left side of the squeegee is less than the desired count value of the counter for detecting the position of the left side of the squeegee. 
     If the answer is Y in the above Step P 192 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 1 in Step P 193 . Then, in Step P 194 , a normal rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program proceeds to Step P 195 . If the answer is N in Step P 192 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 2 in Step P 196 . Then, in Step P 197 , a reverse rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program shifts to the aforementioned Step P 195 . 
     If the answer is Y in Step P 191 , the count value S is loaded from the memory M 59  in Step P 198 . Then, in Step P 199 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 195  mentioned above. 
     Then, in the aforementioned Step P 195 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 200 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 201 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is N, it is determined, in Step P 202 , whether the count value of the counter for detecting the current position of the right side of the squeegee is less than the desired count value of the counter for detecting the position of the right side of the squeegee. 
     If the answer is Y in the above Step P 202 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 1 in Step P 203 . Then, in Step P 204 , a normal rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program proceeds to Step P 205 . If the answer is N in Step P 202 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 2 in Step P 206 . Then, in Step P 207 , a reverse rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program shifts to Step P 205 . 
     If the answer is Y in the aforementioned Step P 201 , the count value S is loaded from the memory M 59  in Step P 208 . Then, in Step P 209 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 205  mentioned above. 
     Then, in Step P 205  mentioned above, the count value S is loaded from the memory M 59 , whereafter it is determined in Step P 210  whether the count value S is 2. If the answer is Y, an enabling signal is outputted in Step P 211  to the counter  76  for counting the total number of revolutions during squeegee throw-on, and the program shifts to Step P 234  to be described later. 
     If the answer is N in the above-mentioned Step P 210 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 , in Step P 212 . Then, in Step P 213 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 214 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is Y, the value of the memory M 60  for storing the rotating direction of the motor for adjusting the left side is loaded in Step P 215 . If the answer is N, the program shifts to Step P 223  to be described later. 
     Then, in Step P 216 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 1. If the answer is Y, outputting of the normal rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 217 , and the program proceeds to Step P 218 . If the answer is N, it is determined in Step P 219  whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 2. 
     If the answer is Y in the above Step P 219 , outputting of the reverse rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 220 , and the program shifts to the aforementioned Step P 218 . If the answer is N, the program shifts to the aforementioned Step P 223 . 
     Then, in the above-mentioned Step P 218 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 221 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 222 . 
     Then, in Step P 223 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 224 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 225 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is Y, the value of the memory M 61  for storing the rotating direction of the motor for adjusting the right side is loaded in Step P 226 . If the answer is N, the program returns to Step P 205 . 
     Then, in Step P 227 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 1. If the answer is Y, outputting of the normal rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 228 , and the program proceeds to Step P 229 . If the answer is N, it is determined in Step P 230  whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 2. 
     If the answer is Y in the above Step P 230 , outputting of the reverse rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 231 , and the program shifts to the aforementioned Step P 229 . If the answer is N, the program returns to Step P 205 . 
     Then, in the aforementioned Step P 229 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. Then, in Step P 232 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 233 . Then, the program returns to Step P 205 . 
     In accordance with the above-described motion flow, when the squeegee throw-on and throw-off automatic control switch  52  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the squeegee  38  is moved to the predetermined retreat position when it opposes the notch  13   b  of the impression cylinder  13 . 
     Then, in Step P 234  shifted from the aforementioned Step P 211 , the table of conversion from the total number of revolutions during squeegee throw-on to the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 64 . Then, in Step P 235 , the count value is loaded from the counter  76  for counting the total number of revolutions during squeegee throw-on, and stored into the memory M 65 . 
     Then, in Step P 236 , the correction amount (count value of the counter) of the squeegee position is obtained from the count value of the counter  76  for counting the total number of revolutions during squeegee throw-on, with the use of the table of conversion from the total number of revolutions during squeegee throw-on to the correction amount (count value of the counter) of the squeegee position, and this correction amount is stored into the memory M 66 . Then, in Step P 237 , the reference throw-on position (count value of the counter) of the squeegee is loaded from the memory M 34 . 
     Then, in Step P 238 , the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 66 . Then, in Step P 239 , the correction amount (count value of the counter) of the squeegee position is added to the reference throw-on position (count value of the counter) of the squeegee to compute the printing position (count value of the counter) of the squeegee, which is stored into the memory M 70 . 
     Then, in Step P 240 , the memory M 55  for storing the desired count value of the counter for detecting the position of the left side of the squeegee is overwritten with the printing position (count value of the counter) of the squeegee. Then, in Step P 241 , the memory M 56  for storing the desired count value of the counter for detecting the position of the right side of the squeegee is overwritten with the printing position (count value of the counter) of the squeegee. 
     Then, in Step P 242 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 243 , the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder is loaded from the memory M 57 . 
     Then, in Step P 244 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder. If the answer is N, the program returns to Step P 242  mentioned above. If the answer is Y, the count value S of the memory M 59  is overwritten with 0 in Step P 245 . Then, in Step P 246 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 247 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 248 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 249 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 250 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is N, it is determined, in Step P 251 , whether the count value of the counter for detecting the current position of the left side of the squeegee is less than the desired count value of the counter for detecting the position of the left side of the squeegee. 
     If the answer is Y in the above Step P 251 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 1 in Step P 252 . Then, in Step P 253 , a normal rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program proceeds to Step P 254 . If the answer is N in Step P 251 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 2 in Step P 255 . Then, in Step P 256 , a reverse rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program shifts to the aforementioned Step P 254 . 
     If the answer is Y in the aforementioned Step P 250 , the count value S is loaded from the memory M 59  in Step P 257 . Then, in Step P 258 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 254  mentioned above. 
     Then, in the aforementioned Step P 254 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 259 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 260 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is N, it is determined, in Step P 261 , whether the count value of the counter for detecting the current position of the right side of the squeegee is less than the desired count value of the counter for detecting the position of the right side of the squeegee. 
     If the answer is Y in the above Step P 261 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 1 in Step P 262 . Then, in Step P 263 , a normal rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program proceeds to Step P 264 . If the answer is N in Step P 261 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 2 in Step P 265 . Then, in Step P 266 , a reverse rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program shifts to Step P 264 . 
     If the answer is Y in the aforementioned Step P 260 , the count value S is loaded from the memory M 59  in Step P 267 . Then, in Step P 268 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 264  mentioned above. 
     Then, in Step P 264  mentioned above, the count value S is loaded from the memory M 59 , whereafter it is determined in Step P 269  whether the count value S is 2. If the answer is Y, the program shifts to Step P 292  to be described later. 
     If the answer is N in the above-mentioned Step P 269 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 , in Step P 270 . Then, in Step P 271 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 272 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is Y, the value of the memory M 60  for storing the rotating direction of the motor for adjusting the left side is loaded in Step P 273 . If the answer is N, the program shifts to Step P 281  to be described later. 
     Then, in Step P 274 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 1. If the answer is Y, outputting of the normal rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 275 , and the program proceeds to Step P 276 . If the answer is N, it is determined in Step P 277  whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 2. 
     If the answer is Y in the above Step P 277 , outputting of the reverse rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 278 , and the program shifts to the aforementioned Step P 276 . If the answer is N, the program shifts to the aforementioned Step P 281 . 
     Then, in the above-mentioned Step P 276 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 279 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 280 . 
     Then, in Step P 281 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 282 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 283 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is Y, the value of the memory M 61  for storing the rotating direction of the motor for adjusting the right side is loaded in Step P 284 . If the answer is N, the program returns to Step P 264 . 
     Then, in Step P 285 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 1. If the answer is Y, outputting of the normal rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 286 , and the program proceeds to Step P 287 . If the answer is N, it is determined in Step P 288  whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 2. 
     If the answer is Y in the above Step P 288 , outputting of the reverse rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 289 , and the program shifts to the aforementioned Step P 287 . If the answer is N, the program returns to Step P 264 . 
     Then, in the aforementioned Step P 287 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. Then, in Step P 290 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 291 . Then, the program returns to Step P 264 . 
     In accordance with the above-described motion flow, when the squeegee throw-on and throw-off automatic control switch  52  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the squeegee  38  is moved to the predetermined printing position when it enters the rotation phase of the rotary screen cylinder  11  corresponding to the position of the rear end of the notch of the impression cylinder  13 . 
     Then, in Step P 292  shifted from the aforementioned Step P 269 , the table of conversion from the total number of revolutions during squeegee throw-onto the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 64 . Then, in Step P 293 , the count value is loaded from the counter  76  for counting the total number of revolutions during squeegee throw-on, and stored into the memory M 65 . 
     Then, in Step P 294 , the correction amount (count value of the counter) of the squeegee position is obtained from the count value of the counter  76  for counting the total number of revolutions during squeegee throw-on, with the use of the table of conversion from the total number of revolutions during squeegee throw-on to the correction amount (count value of the counter) of the squeegee position, and this correction amount is stored into the memory M 66 . Then, in Step P 295 , the reference retreat position (count value of the counter) of the squeegee is loaded from the memory M 53 . 
     Then, in Step P 296 , the correction amount (count value of the counter) of the squeegee position is loaded from the memory M 66 . Then, in Step P 297 , the correction amount (count value of the counter) of the squeegee position is added to the reference retreat position (count value of the counter) of the squeegee to compute the retreat position (count value of the counter) of the squeegee, which is stored into the memory M 67 . 
     Then, in Step P 298 , the memory M 55  for storing the desired count value of the counter for detecting the position of the left side of the squeegee is overwritten with the retreat position (count value of the counter) of the squeegee. Then, in Step P 299 , the memory M 56  for storing the desired count value of the counter for detecting the position of the right side of the squeegee is overwritten with the retreat position (count value of the counter) of the squeegee. 
     Then, in Step P 300 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 301 , the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder is loaded from the memory M 71 . 
     Then, in Step P 302 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder. If the answer is N, the program returns to Step P 300  mentioned above. If the answer is Y, the count value S of the memory M 59  is overwritten with 0 in Step P 303 . Then, in Step P 304 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 305 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 306 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 307 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 308 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is N, it is determined, in Step P 309 , whether the count value of the counter for detecting the current position of the left side of the squeegee is less than the desired count value of the counter for detecting the position of the left side of the squeegee. 
     If the answer is Y in the above Step P 309 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 1 in Step P 310 . Then, in Step P 311 , a normal rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program proceeds to Step P 312 . If the answer is N in Step P 309 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 2 in Step P 313 . Then, in Step P 314 , a reverse rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program shifts to the aforementioned Step P 312 . 
     If the answer is Y in the aforementioned Step P 308 , the count value S is loaded from the memory M 59  in Step P 315 . Then, in Step P 316 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 312  mentioned above. 
     Then, in the aforementioned Step P 312 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 317 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 318 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is N, it is determined, in Step P 319 , whether the count value of the counter for detecting the current position of the right side of the squeegee is less than the desired count value of the counter for detecting the position of the right side of the squeegee. 
     If the answer is Y in the above Step P 319 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 1 in Step P 320 . Then, in Step P 321 , a normal rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program proceeds to Step P 322 . If the answer is N in Step P 319 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 2 in Step P 323 . Then, in Step P 324 , a reverse rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program shifts to the aforementioned Step P 322 . 
     If the answer is Y in the aforementioned Step P 318 , the count value S is loaded from the memory M 59  in Step P 325 . Then, in Step P 326 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 322  mentioned above. 
     Then, in Step P 322  mentioned above, the count value S is loaded from the memory M 59 , whereafter it is determined in Step P 327  whether the count value S is 2. If the answer is Y in this Step P 327 , it is determined in Step P 328  whether the cylinder engagement signal for the rotary screen cylinder is ON. If the answer is Y in this step, the program returns to the aforementioned Step P 234 . If the answer is N, the program returns to the aforementioned Step P 121 . 
     If the answer is N in the above-mentioned Step P 327 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 , in Step P 329 . Then, in Step P 330 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 331 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is Y, the value of the memory M 60  for storing the rotating direction of the motor for adjusting the left side is loaded in Step P 332 . If the answer is N, the program shifts to Step P 340  to be described later. 
     Then, in Step P 333 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 1. If the answer is Y, outputting of the normal rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 334 , and the program proceeds to Step P 335 . If the answer is N, it is determined in Step P 336  whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 2. 
     If the answer is Y in the above Step P 336 , outputting of the reverse rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 337 , and the program shifts to the aforementioned Step P 335 . If the answer is N, the program shifts to the aforementioned Step P 340 . 
     Then, in the aforementioned Step P 335 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 338 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 339 . 
     Then, in Step P 340 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 341 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 342 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is Y, the value of the memory M 61  for storing the rotating direction of the motor for adjusting the right side is loaded in Step P 343 . If the answer is N, the program returns to Step P 322 . 
     Then, in Step P 344 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 1. If the answer is Y, outputting of the normal rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 345 , and the program proceeds to Step P 346 . If the answer is N, it is determined in Step P 347  whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 2. 
     If the answer is Y in the above Step P 347 , outputting of the reverse rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 348 , and the program shifts to the aforementioned Step P 346 . If the answer is N, the program returns to Step P 322 . 
     Then, in the aforementioned Step P 346 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. Then, in Step P 349 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 350 . Then, the program returns to Step P 322 . 
     In accordance with the above-described motion flow, when the squeegee throw-on and throw-off automatic control switch  52  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the squeegee  38  is moved to the predetermined retreat position when it enters the rotation phase of the rotary screen cylinder  11  corresponding to the position of the leading end of the notch of the impression cylinder  13 . 
     Then, in Step P 351  shifted from the aforementioned Step P 119 , the throw-off position (count value of the counter) of the squeegee is loaded from the memory M 54 . 
     Then, in Step P 352 , the memory M 55  for storing the desired count value of the counter for detecting the position of the left side of the squeegee is overwritten with the throw-off position (count value of the counter) of the squeegee. Then, in Step P 353 , the memory M 56  for storing the desired count value of the counter for detecting the position of the right side of the squeegee is overwritten with the throw-off position (count value of the counter) of the squeegee. 
     Then, in Step P 354 , the count value S of the memory M 59  is overwritten with 0, whereafter the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0 in Step P 355 . Then, in Step P 356 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 357 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 358 , the rotation phase of the rotary screen cylinder during squeegee throw-off is loaded from the memory M 58 . 
     Then, in Step P 359 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during squeegee throw-off. If the answer is N, the program returns to Step P 357  mentioned above. If the answer is Y, the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 , in Step P 360 . Then, in Step P 361 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 362 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is N, it is determined, in Step P 363 , whether the count value of the counter for detecting the current position of the left side of the squeegee is less than the desired count value of the counter for detecting the position of the left side of the squeegee. 
     If the answer is Y in the above Step P 363 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 1 in Step P 364 . Then, in Step P 365 , a normal rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program proceeds to Step P 366 . If the answer is N in Step P 363 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 2 in Step P 367 . Then, in Step P 368 , a reverse rotation command is outputted to the driver  66  for the motor for adjusting the left side, whereafter the program shifts to the aforementioned Step P 366 . 
     If the answer is Y in the aforementioned Step P 362 , the count value S is loaded from the memory M 59  in Step P 369 . Then, in Step P 370 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 366  mentioned above. 
     Then, in the aforementioned Step P 366 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 371 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 372 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is N, it is determined, in Step P 373 , whether the count value of the counter for detecting the current position of the right side of the squeegee is less than the desired count value of the counter for detecting the position of the right side of the squeegee. 
     If the answer is Y in the above Step P 373 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 1 in Step P 374 . Then, in Step P 375 , a normal rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program proceeds to Step P 376 . If the answer is N in Step P 373 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 2 in Step P 377 . Then, in Step P 378 , a reverse rotation command is outputted to the driver  70  for the motor for adjusting the right side, whereafter the program shifts to the aforementioned Step P 376 . 
     If the answer is Y in the aforementioned Step P 372 , the count value S is loaded from the memory M 59  in Step P 379 . Then, in Step P 380 , 1 is added to the count value S of the memory M 59  for overwriting, whereafter the program shifts to Step P 376  mentioned above. 
     Then, in Step P 376  mentioned above, the count value S is loaded from the memory M 59 , whereafter it is determined in Step P 381  whether the count value S is 2. If the answer is Y in this Step P 381 , outputting of the enabling signal to the counter  76  for counting the total number of revolutions during squeegee throw-on is stopped in Step P 382 , and the program returns to Step P 1 . 
     Then, in Step P 383 , the count value is loaded from the counter  68  for detecting the current position of the left side of the squeegee, and stored into the memory M 62 . Then, in Step P 384 , the desired count value of the counter for detecting the position of the left side of the squeegee is loaded from the memory M 55 . 
     Then, in Step P 385 , it is determined whether the count value of the counter for detecting the current position of the left side of the squeegee is equal to the desired count value of the counter for detecting the position of the left side of the squeegee. If the answer is Y, the value of the memory M 60  for storing the rotating direction of the motor for adjusting the left side is loaded in Step P 386 . If the answer is N, the program shifts to Step P 394  to be described later. 
     Then, in Step P 387 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 1. If the answer is Y, outputting of the normal rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 388 , and the program proceeds to Step P 389 . If the answer is N, it is determined in Step P 390  whether the value of the memory for storing the rotating direction of the motor for adjusting the left side is 2. 
     If the answer is Y in the above Step P 390 , outputting of the reverse rotation command to the driver  66  for the motor for adjusting the left side is stopped in Step P 391 , and the program shifts to the aforementioned Step P 389 . If the answer is N, the program shifts to the aforementioned Step P 394 . 
     Then, in the aforementioned Step P 389 , the memory M 60  for storing the rotating direction of the motor for adjusting the left side is overwritten with 0. Then, in Step P 392 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 393 . 
     Then, in Step P 394 , the count value is loaded from the counter  72  for detecting the current position of the right side of the squeegee, and stored into the memory M 63 . Then, in Step P 395 , the desired count value of the counter for detecting the position of the right side of the squeegee is loaded from the memory M 56 . 
     Then, in Step P 396 , it is determined whether the count value of the counter for detecting the current position of the right side of the squeegee is equal to the desired count value of the counter for detecting the position of the right side of the squeegee. If the answer is Y, the value of the memory M 61  for storing the rotating direction of the motor for adjusting the right side is loaded in Step P 397 . If the answer is N, the program returns to Step P 376 . 
     Then, in Step P 398 , it is determined whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 1. If the answer is Y, outputting of the normal rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 399 , and the program proceeds to Step P 400 . If the answer is N, it is determined in Step P 401  whether the value of the memory for storing the rotating direction of the motor for adjusting the right side is 2. 
     If the answer is Y in the above Step P 401 , outputting of the reverse rotation command to the driver  70  for the motor for adjusting the right side is stopped in Step P 402 , and the program shifts to the aforementioned Step P 400 . If the answer is N, the program returns to Step P 376 . 
     Then, in the aforementioned Step P 400 , the memory M 61  for storing the rotating direction of the motor for adjusting the right side is overwritten with 0. Then, in Step P 403 , the count value S is loaded from the memory M 59 , whereafter 1 is added to the count value S of the memory M 59  for overwriting in Step P 404 . Then, the program returns to Step P 376 . 
     In accordance with the above-described motion flow, when the squeegee throw-on and throw-off automatic control switch  52  is brought to the OFF-state, the squeegee  38  is moved to the throw-off position. 
     According to the present Embodiment 1, as described above, the throw-on position of the squeegee  38  during printing is preset, based on the type of the material W to be printed (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), in conformity with the thickness of the material to be printed, the material for the screen printing forme  11   c , the thickness of the screen printing forme, the picture pattern area rate, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the squeegee, and the thickness of the squeegee. Thus, burden on the operator can be lessened by automation, and the rate of operation can be increased and the occurrence of wasted paper can be curtailed by shortening the period of time until normal printing products can be obtained by printing. 
     In the present Embodiment 1, moreover, even when the squeegee  38  is located at a position where it opposes the notch  13   b  of the impression cylinder  13  (i.e., the retreat position), the leading end of the squeegee  38  does not leave the inner peripheral surface of the screen printing forme  11   c , and only its pressure exerted on this surface (i.e., pressing force) is rendered lower than the pressure during printing. Thus, the screen printing forme  11   c  is prevented from being pushed into the notch  13   b  of the impression cylinder  13  by the squeegee  38  and damaged thereby, and there is no ink leaking out toward the downstream side in the rotating direction of the screen printing forme  11   c , so that deterioration of printing quality is prevented. 
     That is, the following problems are avoided: Because of leaks of ink toward the downstream side in the rotating direction of the screen printing forme  11   c , the amount of ink remaining in front of the squeegee  38  becomes small to decrease the ink density at the start of printing. The ink leaking out toward the downstream side leaks out through the holes of the picture pattern portion under a centrifugal force during high speed rotation, adheres to outside portions of the holes, and sticks to the outside of the picture pattern portion during printing, thereby deteriorating printing quality. 
     In the present Embodiment 1, the control pressure may be switched using a hydraulic or pneumatic actuator instead of the motor  36 A for adjusting the left side and the motor  36 B for adjusting the right side. Moreover, the motors  36 A and  36 B are disposed on the right side and the left side. However, there may be adopted a configuration in which a one-sided motor moves the right and left sides, for example, by connecting the right and left sides by a lever mechanism. 
     Embodiment 2 
       FIG. 13  is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 2 of the present invention.  FIG. 14(   a ) is an explanation drawing of an ink supply system.  FIG. 14(   b ) is an explanation drawing of an ink supply pipe.  FIGS. 15(   a ) to  15 ( c ) are control block diagrams of a doctor roller throw-on and throw-off control device.  FIGS. 16(   a ) to  16 ( e ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 17(   a ) to  17 ( d ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 18(   a ) to  18 ( c ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 19(   a ) to  19 ( c ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 20(   a ) to  20 ( c ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 21(   a ) to  21 ( c ) are motion flow charts of the doctor roller throw-on and throw-off control device.  FIGS. 22(   a ) to  22 ( c ) are motion flow charts of the doctor roller throw-on and throw-off control device. 
     The present Embodiment 2 is an embodiment in which a stepping motor  36 Aa for adjusting a left side and a stepping motor  36 Bb for adjusting a right side (see  FIGS. 15(   a ) and  15 ( b )) are used instead of the motor  36 A for adjusting the left side of the support shaft  27  and the motor  36 B for adjusting the right side of the support shaft  27  in Embodiment 1, and a doctor roller  90  is used instead of the squeegee  38  as the liquid transfer member, as shown in  FIG. 13 . 
     The doctor roller  90  has a double structure composed of an inner roller  90   a  formed from a metal and an outer roller  90   b  formed from rubber. The doctor roller  90  is rotatably supported on a support shaft  27  via bearings  92  at left and right end members  91   a  and  91   b  fitted into the inner roller  90   a.    
     As shown in  FIGS. 14(   a ) and  14 ( b ), an ink supply pipe  93  is horizontally installed within the screen printing forme  11   c , and ink stored within an external tank  94  is supplied to the ink supply pipe  93  by a pump  95 . The ink is dropped from the ink supply pipe  93  toward the inner peripheral surface of the screen printing forme  11   c  at multiple points in the cylinder axis direction of the rotary screen cylinder  11 . 
     Thus, the outer peripheral surface of the doctor roller  90  makes a rolling contact with the inner peripheral surface of the screen printing forme  11   c , whereby the ink supplied to the interior of the screen printing forme  11   c  through the ink supply pipe  93  is transferred to the printing surface of the material W to be printed via the holes of the screen printing forme  11   c.    
     Other features are the same as those in Embodiment 1, so that duplicate explanations are omitted by reference to  FIGS. 1 to 4(   a ),  4 ( b ). 
     The doctor roller throw-on and throw-off control device  40 B of the present Embodiment 2 comprises CPU  41 , RAM  42 , ROM  43 , and input/output devices  44  to  50  connected together by BUS (bus line), as shown in  FIGS. 15(   a ) to  15 ( c ). To the BUS (bus line), the following memories are connected: A memory M 1  for storing the type of the material to be printed, a memory M 2  for storing the thickness of the material to be printed, a memory M 3  for storing the material for the screen printing forme, a memory M 4  for storing the thickness of the screen printing forme, a memory M 5   a  for storing the open area rate of the screen printing forme, a memory M 6  for storing the mesh size of the screen printing forme, a memory M 7  for storing the viscosity of ink, a memory M 8  for storing the yield value of ink, a memory M 9  for storing the type of a pigment of ink, a memory M 10   a  for storing the material for the doctor roller, and a memory M 11   a  for storing the surface hardness of the doctor roller. 
     To the BUS (bus line), the following memories are further connected: A memory M 12   a  for storing a table of conversion from the type of the material to be printed to the throw-on position (count value of a counter) of the doctor roller, a memory M 13   a  for storing the provisional reference throw-on position (count value of the counter) of the doctor roller, a memory M 14   a  for storing a table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the doctor roller, a memory M 15   a  for storing the first correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 16   a  for storing a table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, a memory M 17   a  for storing the second correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 18   a  for storing a table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, a memory M 19   a  for storing the third correction value (count value of the counter) of the throw-on position of the doctor roller, and a memory M 21   a  for storing the fourth correction value (count value of the counter) of the throw-on position of the doctor roller. 
     To the BUS (bus line), the following memories are further connected: A memory M 22   a  for storing a table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, a memory M 23   a  for storing the fifth correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 24   a  for storing a table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the doctor roller, a memory M 25   a  for storing the sixth correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 26   a  for storing a table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the doctor roller, a memory M 27   a  for storing the seventh correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 28   a  for storing a table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the doctor roller, a memory M 29   a  for storing the eighth correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 30   a  for storing a table of conversion from the material for the doctor roller to the throw-on position (count value of the counter) of the doctor roller, a memory M 31   a  for storing the ninth correction value (count value of the counter) of the throw-on position of the doctor roller, a memory M 32   a  for storing a table of conversion from the surface hardness of the doctor roller to the throw-on position (count value of the counter) of the doctor roller, and a memory M 33   a  for storing the tenth correction value (count value of the counter) of the throw-on position of the doctor roller. 
     To the BUS (bus line), the following memories are further connected: A memory M 34   a  for storing the reference throw-on position (count value of the counter) of the doctor roller, a memory M 35   a  for storing a table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the doctor roller, a memory M 36   a  for storing the provisional reference retreat position (count value of the counter) of the doctor roller, a memory M 37   a  for storing a table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, a memory M 38   a  for storing the first correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 40   a  for storing the second correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 41   a  for storing a table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, a memory M 42   a  for storing the third correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 43   a  for storing a table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the doctor roller, a memory M 44   a  for storing the fourth correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 45   a  for storing a table of conversion from the yield value of ink to the retreat position (count value of the counter) of the doctor roller, and a memory M 46   a  for storing the fifth correction value (count value of the counter) of the retreat position of the doctor roller. 
     To the BUS (bus line), the following memories are further connected: A memory M 47   a  for storing a table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the doctor roller, a memory M 48   a  for storing the sixth correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 49   a  for storing a table of conversion from the material for the doctor roller to the retreat position (count value of the counter) of the doctor roller, a memory M 50   a  for storing the seventh correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 51   a  for storing a table of conversion from the surface hardness of the doctor roller to the retreat position (count value of the counter) of the doctor roller, a memory M 52   a  for storing the eighth correction value (count value of the counter) of the retreat position of the doctor roller, a memory M 53   a  for storing the reference retreat position (count value of the counter) of the doctor roller, a memory M 54   a  for storing the throw-off position (count value of the counter) of the doctor roller, and a memory M 58   a  for storing the rotation phase of the rotary screen cylinder during doctor roller throw-off. 
     To the BUS (bus line), the following memories are further connected: A memory M 60   a  for storing the presence or absence of rotation of a stepping motor for adjusting a left side, a memory M 61   a  for storing the presence or absence of rotation of a stepping motor for adjusting a right side, a memory M 62   a  for storing the count value of a counter for detecting the current position of the left side of the doctor roller, a memory M 63   a  for storing the count value of a counter for detecting the current position of the right side of the doctor roller, a memory M 64   a  for storing a table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position, a memory M 65   a  for storing the count value of a counter for counting the total number of revolutions during doctor roller throw-on, a memory M 66   a  for storing the correction amount (count value of the counter) of the doctor roller position, a memory M 67   a  for storing the retreat position (count value of the counter) of the doctor roller, a memory M 68  for storing the count value of a counter for detecting the rotation phase of the rotary screen cylinder, a memory M 69   a  for storing the rotation phase of the rotary screen cylinder during doctor roller throw-on, a memory M 70   a  for storing the printing position (count value of the counter) of the doctor roller, a memory M 71  for storing the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder, a memory M 72  for storing a table of conversion from the open area rate of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, a memory M 73  for storing a table of conversion from the open area rate of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, a memory M 74  for storing the amount of movement of the left side of the doctor roller, a memory M 75  for storing the amount of movement of the right side of the doctor roller, a memory M 76  for storing the absolute value of the amount of movement of the left side of the doctor roller, a memory M 77  for storing the absolute value of the amount of movement of the right side of the doctor roller, and a memory M 78  for storing the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder. 
     To the input/output device  44 , the following are connected: A doctor roller throw-on and throw-off automatic control switch  52   a , an input device  53  such as a keyboard, a display device  54  such as CRT or a display, and an output device  55  such as a printer or a floppy disk (registered trademark) drive. 
     To the input/output device  45 , the following are connected: A setting instrument  56  for the type of the material to be printed, a setting instrument  57  for the thickness of the material to be printed, a setting instrument  58  for the material for the screen printing forme, a setting instrument  59  for the thickness of the screen printing forme, a setting instrument  60  for the mesh size of the screen printing forme, a setting instrument  61  for the viscosity of ink, a setting instrument  62  for the yield value of ink, a setting instrument  63  for the type of the pigment of ink, a setting instrument  64   a  for the material for the doctor roller, a setting instrument  65   a  for the surface hardness of the doctor roller, and a setting instrument  80  for the open area rate of the screen printing forme. 
     To the input/output device  46 , the stepping motor  36 Aa for adjusting the left side is connected via a driver  66   a  for the stepping motor for adjusting the left side, and a counter  68   a  for detecting the current position of the left side of the doctor roller is also connected. 
     To the input/output device  47 , the stepping motor  36 Bb for adjusting the right side is connected via a driver  70   a  for the stepping motor for adjusting the right side, and a counter  72   a  for detecting the current position of the right side of the doctor roller is also connected. 
     To the input/output device  48 , a rotary encoder  75  for detecting the rotation phase of the rotary screen cylinder is connected via a counter  74  for detecting the rotation phase of the rotary screen cylinder. The rotary encoder  75  for detecting the rotation phase of the rotary screen cylinder is provided on a rotating part of the rotary screen printing press rotating in synchronism with the rotary screen cylinder in such a manner as to generate a zero pulse in the reference rotation phase of the rotary screen cylinder. Thus, the counter  74  for detecting the rotation phase of the rotary screen cylinder is reset in the reference rotation phase of the rotary screen cylinder each time the rotary screen cylinder makes one rotation. Then, the counter  74  for detecting the rotation phase of the rotary screen cylinder counts clock pulses generated in accordance with the rotation of the rotary screen cylinder, producing a count value conformed to the rotation phase of the rotary screen cylinder. 
     To the input/output device  49 , a sensor  77  for detecting one rotation of the rotary screen cylinder is connected via a counter  76   a  for counting the total number of revolutions during doctor roller throw-on. The sensor  77  for detecting one rotation of the rotary screen cylinder is provided on a rotating part of the rotary screen printing press so as to produce one pulse each time the rotary screen cylinder makes one rotation. Thus, the counter  76   a  for counting the total number of revolutions during doctor roller throw-on is adapted to count the number of revolutions of the rotary screen cylinder in an operating state. 
     To the input/output device  50 , a cylinder engagement circuit  78  for the rotary screen cylinder is connected. 
     The control actions or motions of the doctor roller throw-on and throw-off control device  40 B configured as above will be described in detail based on the motion flow charts of  FIGS. 16(   a ) to  16 ( e ),  FIGS. 17(   a ) to  17 ( d ),  FIGS. 18(   a ) to  18 ( c ),  FIGS. 19(   a ) to  19 ( c ),  FIGS. 20(   a ) to  20 ( c ),  FIGS. 21(   a ) to  21 ( c ), and  FIGS. 22(   a ) to  22 ( c ). 
     In Step P 1 , it is determined whether there is an input to the setting instrument  56  for the type of the material to be printed. If the answer is Y (yes), the type of the material W to be printed is loaded from the setting instrument  56  for the type of the material to be printed, and stored into the memory M 1 , in Step P 2 , and the program proceeds to Step P 3 . If the answer is N (no), the program directly shifts to Step P 3 . 
     Then, in Step P 3 , it is determined whether there is an input to the setting instrument  57  for the thickness of the material to be printed. If the answer is Y, the thickness of the material to be printed is loaded from the setting instrument  57  for the thickness of the material to be printed, and stored into the memory M 2 , in Step P 4 . Then, the program proceeds to Step P 5 . If the answer is N, the program directly shifts to Step P 5 . 
     Then, in Step P 5 , it is determined whether there is an input to the setting instrument  58  for the material for the screen printing forme. If the answer is Y, the material for the screen printing forme  11   c  is loaded from the setting instrument  58  for the material for the screen printing forme, and stored into the memory M 3 , in Step P 6 . Then, the program proceeds to Step P 7 . If the answer is N, the program directly shifts to Step P 7 . 
     Then, in Step P 7 , it is determined whether there is an input to the setting instrument  59  for the thickness of the screen printing forme. If the answer is Y, the thickness of the screen printing forme is loaded from the setting instrument  59  for the thickness of the screen printing forme, and stored into the memory M 4 , in Step P 8 . Then, the program proceeds to Step P 9 . If the answer is N, the program directly shifts to Step P 9 . 
     Then, in Step P 9 , it is determined whether there is an input to the setting instrument  80  for the open area rate of the screen printing forme. If the answer is Y, the open area rate of the screen printing forme is loaded from the setting instrument  80  for the open area rate of the screen printing forme, and stored into the memory M 5   a , in Step P 10 . Then, the program proceeds to Step P 11 . If the answer is N, the program directly shifts to Step P 11 . 
     Then, in Step P 11 , it is determined whether there is an input to the setting instrument  60  for the mesh size of the screen printing forme. If the answer is Y, the mesh size of the screen printing forme  11   c  is loaded from the setting instrument  60  for the mesh size of the screen printing forme, and stored into the memory M 6 , in Step P 12 . Then, the program proceeds to Step P 13 . If the answer is N, the program directly shifts to Step P 13 . 
     Then, in Step P 13 , it is determined whether there is an input to the setting instrument  61  for the viscosity of ink. If the answer is Y, the viscosity of ink is loaded from the setting instrument  61  for the viscosity of ink, and stored into the memory M 7 , in Step P 14 . Then, the program proceeds to Step P 15 . If the answer is N, the program directly shifts to Step P 15 . 
     Then, in Step P 15 , it is determined whether there is an input to the setting instrument  62  for the yield value of ink. If the answer is y, the yield value of ink is loaded from the setting instrument  62  for the yield value of ink, and stored into the memory M 8 , in Step P 16 . Then, the program proceeds to Step P 17 . If the answer is N, the program directly shifts to Step P 17 . 
     Then, in Step P 17 , it is determined whether there is an input to the setting instrument  63  for the type of the pigment of ink. If the answer is Y, the type of the pigment of ink is loaded from the setting instrument  63  for the type of the pigment of ink, and stored into the memory M 9 , in Step P 18 . Then, the program proceeds to Step P 19 . If the answer is N, the program directly shifts to Step P 19 . 
     Then, in Step P 19 , it is determined whether there is an input to the setting instrument  64   a  for the material for the doctor roller. If the answer is Y, the material for the doctor roller  90  is loaded from the setting instrument  64   a  for the material for the doctor roller, and stored into the memory M 10   a , in Step P 20 . Then, the program proceeds to Step P 21 . If the answer is N, the program directly shifts to Step P 21 . 
     Then, in Step P 21 , it is determined whether there is an input to the setting instrument  65   a  for the surface hardness of the doctor roller. If the answer is Y, the surface hardness of the doctor roller is loaded from the setting instrument  65   a  for the surface hardness of the doctor roller, and stored into the memory M 11   a , in Step P 22 . Then, the program proceeds to Step P 23 . If the answer is N, the program directly shifts to Step P 23 . 
     Then, in Step P 23 , it is determined whether the doctor roller throw-on and throw-off automatic control switch  52   a  is ON. If the answer is Y, the table of conversion from the type of the material to be printed to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 12   a  in Step P 24 . If the answer is N, the program returns to Step P 1 . 
     Then, in Step P 25 , the type of the material W to be printed is loaded from the memory M 1 . Then, in Step P 26 , the provisional reference throw-on position (count value of the counter) of the doctor roller is obtained from the type of the material W to be printed, with the use of the table of conversion from the type of the material to be printed to the throw-on position (count value of the counter) of the doctor roller, and is stored into the memory M 13   a.    
     Then, in Step P 27 , the type of the material W to be printed is loaded from the memory M 1 . Then, in Step P 28 , the table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the type of the material to be printed, is loaded from the memory M 14   a.    
     Then, in Step P 29 , the thickness of the material to be printed is loaded from the memory M 2 . Then, in Step P 30 , the first correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the thickness of the material to be printed, with the use of the table of conversion from the thickness of the material to be printed to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the type of the material to be printed, and this correction value is stored into the memory M 15   a.    
     Then, in Step P 31 , the table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 16   a . Then, in Step P 32 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 33 , the second correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the material for the screen printing forme  11   c , with the use of the table of conversion from the material for the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 17   a.    
     Then, in Step P 34 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 35 , the table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme, is loaded from the memory M 18   a.    
     Then, in Step P 36 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 37 , the third correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the thickness of the screen printing forme, with the use of the table of conversion from the thickness of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme, and this correction value is stored into the memory M 19   a.    
     Then, in Step P 38 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 39 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 40 , the table of conversion from the open area rate of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 72 . 
     Then, in Step P 41 , the open area rate of the screen printing forme is loaded from the memory M 5   a . Then, in Step P 42 , the fourth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the open area rate of the screen printing forme, with the use of the table of conversion from the open area rate of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 21   a.    
     Then, in Step P 43 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 44 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 45 , the table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 22   a.    
     Then, in Step P 46 , the mesh size of the screen printing forme is loaded from the memory M 6 . Then, in Step P 47 , the fifth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the mesh size of the screen printing forme, with the use of the table of conversion from the mesh size of the screen printing forme to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 23   a.    
     Then, in Step P 48 , the table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 24   a . Then, in Step P 49 , the viscosity of ink is loaded from the memory M 7 . Then, in Step P 50 , the sixth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the viscosity of ink with the use of the table of conversion from the viscosity of ink to the throw-on position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 25   a.    
     Then, in Step P 51 , the table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 26   a . Then, in Step P 52 , the yield value of ink is loaded from the memory M 8 . Then, in Step P 53 , the seventh correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the yield value of ink with the use of the table of conversion from the yield value of ink to the throw-on position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 27   a.    
     Then, in Step P 54 , the table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 28   a . Then, in Step P 55 , the type of the pigment of ink is loaded from the memory M 9 . Then, in Step P 56 , the eighth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the type of the pigment of ink with the use of the table of conversion from the type of the pigment of ink to the throw-on position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 29   a.    
     Then, in Step P 57 , the table of conversion from the material for the doctor roller to the throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 30   a . Then, in Step P 58 , the material for the doctor roller  90  is loaded from the memory M 10   a . Then, in Step P 59 , the ninth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the material for the doctor roller  90  with the use of the table of conversion from the material for the doctor roller to the throw-on position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 31   a.    
     Then, in Step P 60 , the material for the doctor roller  90  is loaded from the memory M 10   a . Then, in Step P 61 , the table of conversion from the surface hardness of the doctor roller to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the doctor roller, is loaded from the memory M 32   a.    
     Then, in Step P 62 , the surface hardness of the doctor roller is loaded from the memory M 11   a . Then, in Step P 63 , the tenth correction value (count value of the counter) of the throw-on position of the doctor roller is obtained from the surface hardness of the doctor roller with the use of the table of conversion from the surface hardness of the doctor roller to the throw-on position (count value of the counter) of the doctor roller, which is commensurate with the material for the doctor roller, and this correction value is stored into the memory M 33   a.    
     Then, in Step P 64 , the provisional reference throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 13   a , whereafter, in Step P 65 , the first correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 15   a . Then, in Step P 66 , the second correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 17   a.    
     Then, in Step P 67 , the third correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 19   a , whereafter, in Step P 68 , the fourth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 21   a . Then, in Step P 69 , the fifth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 23   a.    
     Then, in Step P 70 , the sixth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 25   a , whereafter, in Step P 71 , the seventh correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 27   a . Then, in Step P 72 , the eighth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 29   a.    
     Then, in Step P 73 , the ninth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 31   a , whereafter, in Step P 74 , the tenth correction value (count value of the counter) of the throw-on position of the doctor roller is loaded from the memory M 33   a.    
     Then, in Step P 75 , the first correction value (count value of the counter) of the throw-on position of the doctor roller, the second correction value (count value of the counter) of the throw-on position of the doctor roller, the third correction value (count value of the counter) of the throw-on position of the doctor roller, the fourth correction value (count value of the counter) of the throw-on position of the doctor roller, the fifth correction value (count value of the counter) of the throw-on position of the doctor roller, the sixth correction value (count value of the counter) of the throw-on position of the doctor roller, the seventh correction value (count value of the counter) of the throw-on position of the doctor roller, the eighth correction value (count value of the counter) of the throw-on position of the doctor roller, the ninth correction value (count value of the counter) of the throw-on position of the doctor roller, and the tenth correction value (count value of the counter) of the throw-on position of the doctor roller are added to the provisional reference throw-on position (count value of the counter) of the doctor roller to compute the reference throw-on position (count value of the counter) of the doctor roller, and this reference throw-on position (count value of the counter) of the doctor roller is stored into the memory M 34   a.    
     In accordance with the above-described motion flow, the throw-on position of the doctor roller  90  during printing is preset, based on the type of the material W to be printed (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), in conformity with the thickness of the material to be printed, the material for the screen printing forme  11   c , the thickness of the screen printing forme, the open area rate of the screen printing forme, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the doctor roller, and the surface hardness of the doctor roller. 
     Then, in Step P 76 , the table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 35   a . Then, in Step P 77 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 78 , the provisional reference retreat position (count value of the counter) of the doctor roller is obtained from the material for the screen printing forme  11   c  with the use of the table of conversion from the material for the screen printing forme to the retreat position (count value of the counter) of the doctor roller, and is stored into the memory M 36   a.    
     Then, in Step P 79 , the material for the screen printing forme  11   c  is loaded from the memory M 3 . Then, in Step P 80 , the table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme, is loaded from the memory M 37   a.    
     Then, in Step P 81 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 82 , the first correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the thickness of the screen printing forme with the use of the table of conversion from the thickness of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme, and this correction value is stored into the memory M 38   a.    
     Then, in Step P 83 , the material for the screen printing forme  11   c  is loaded from the memory M 3 , whereafter, in Step P 84 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 85 , the table of conversion from the open area rate of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 73 . 
     Then, in Step P 86 , the open area rate of the screen printing forme is loaded from the memory M 5   a . Then, in Step P 87 , the second correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the open area rate of the screen printing forme with the use of the table of conversion from the open area rate of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 40   a.    
     Then, in Step P 88 , the material for the screen printing forme is loaded from the memory M 3 . Then, in Step P 89 , the thickness of the screen printing forme is loaded from the memory M 4 . Then, in Step P 90 , the table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, is loaded from the memory M 41   a.    
     Then, in Step P 91 , the mesh size of the screen printing forme  11   c  is loaded from the memory M 6 . Then, in Step P 92 , the third correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the mesh size of the screen printing forme  11   c  with the use of the table of conversion from the mesh size of the screen printing forme to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the screen printing forme and the thickness of the screen printing forme, and this correction value is stored into the memory M 42   a.    
     Then, in Step-P 93 , the table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 43   a . Then, in Step P 94 , the viscosity of ink is loaded from the memory M 7 . Then, in Step P 95 , the fourth correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the viscosity of ink with the use of the table of conversion from the viscosity of ink to the retreat position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 44   a.    
     Then, in Step P 96 , the table of conversion from the yield value of ink to the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 45   a . Then, in Step P 97 , the yield value of ink is loaded from the memory M 8 . Then, in Step P 98 , the fifth correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the yield value of ink with the use of the table of conversion from the yield value of ink to the retreat position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 46   a.    
     Then, in Step P 99 , the table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 47   a . Then, in Step P 100 , the type of the pigment of ink is loaded from the memory M 9 . Then, in Step P 101 , the sixth correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the type of the pigment of ink with the use of the table of conversion from the type of the pigment of ink to the retreat position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 48   a.    
     Then, in Step P 102 , the table of conversion from the material for the doctor roller to the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 49   a . Then, in Step P 103 , the material for the doctor roller is loaded from the memory M 10   a . Then, in Step P 104 , the seventh correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the material for the doctor roller with the use of the table of conversion from the material for the doctor roller to the retreat position (count value of the counter) of the doctor roller, and this correction value is stored into the memory M 50   a.    
     Then, in Step P 105 , the material for the doctor roller is loaded from the memory M 10   a . Then, in Step P 106 , the table of conversion from the surface hardness of the doctor roller to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the doctor roller, is loaded from the memory M 51   a.    
     Then, in Step P 107 , the surface hardness of the doctor roller is loaded from the memory M 11   a . Then, in Step P 108 , the eighth correction value (count value of the counter) of the retreat position of the doctor roller is obtained from the surface hardness of the doctor roller with the use of the table of conversion from the surface hardness of the doctor roller to the retreat position (count value of the counter) of the doctor roller, which is commensurate with the material for the doctor roller, and this correction value is stored into the memory M 52   a.    
     Then, in Step P 109 , the provisional reference retreat position (count value of the counter) of the doctor roller is loaded from the memory M 36   a , whereafter, in Step P 110 , the first correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 38   a . Then, in Step P 111 , the second correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 40   a.    
     Then, in Step P 112 , the third correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 42   a , whereafter, in Step P 113 , the fourth correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 44   a . Then, in Step P 114 , the fifth correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 46   a.    
     Then, in Step P 115 , the sixth correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 48   a , whereafter, in Step P 116 , the seventh correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 50   a . Then, in Step P 117 , the eighth correction value (count value of the counter) of the retreat position of the doctor roller is loaded from the memory M 52   a.    
     Then, in Step P 118 , the first correction value (count value of the counter) of the retreat position of the doctor roller, the second correction value (count value of the counter) of the retreat position of the doctor roller, the third correction value (count value of the counter) of the retreat position of the doctor roller, the fourth correction value (count value of the counter) of the retreat position of the doctor roller, the fifth correction value (count value of the counter) of the retreat position of the doctor roller, the sixth correction value (count value of the counter) of the retreat position of the doctor roller, the seventh correction value (count value of the counter) of the retreat position of the doctor roller, and the eighth correction value (count value of the counter) of the retreat position of the doctor roller are added to the provisional reference retreat position (count value of the counter) of the doctor roller to compute the reference retreat position (count value of the counter) of the doctor roller. This reference retreat position (count value of the counter) of the doctor roller is stored into the memory M 53   a . The reference retreat position (count value of the counter) of the doctor roller obtained is a position closer to the throw-off position of the doctor roller than to the reference throw-on position of the doctor roller obtained in Step P 75 , in other words, a position at which the doctor roller  90  does not leave the inner peripheral surface of the screen printing forme  11   c , and its pressing force decreases. 
     In accordance with the above-described motion flow, the retreat position of the doctor roller  90  when opposing the notch  13   b  of the impression cylinder  13  (in other words, the pressing force acting on the inner peripheral surface of the screen printing forme  11   c ) is preset, based on the material for the screen printing forme  11   c , in conformity with the thickness of the screen printing forme, the open area rate of the screen printing forme, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the doctor roller, and the surface hardness of the doctor roller. 
     Then, in Step P 119 , it is determined whether the doctor roller throw-on and throw-off automatic control switch  52   a  is OFF. If the answer is Y (yes), the program shifts to Step P 291  to be described later. If the answer is N (no), it is determined, in Step P 120 , whether a cylinder engagement signal from the cylinder engagement circuit  78  for the rotary screen cylinder is ON. 
     If the answer is Y in the above Step P 120 , the program shifts to Step P 160  to be described later. If the answer is N, the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a  in Step P 121 . 
     Then, in Step P 122 , the count value is loaded from the counter  68   a  for detecting the current position of the left side of the doctor roller, and stored into the memory M 62   a . Then follows Step P 123  in which the count value of the counter for detecting the current position of the left side of the doctor roller is subtracted from the throw-off position (count value of the counter) of the doctor roller to compute the amount of movement of the left side of the doctor roller, which is stored into the memory M 74 . 
     Then, in Step P 124 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then follows Step P 125  in which the count value of the counter for detecting the current position of the right side of the doctor roller is subtracted from the throw-off position (count value of the counter) of the doctor roller to compute the amount of movement of the right side of the doctor roller, which is stored into the memory M 75 . 
     Then, in Step P 126 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 127 , the rotation phase of the rotary screen cylinder during doctor roller throw-off is loaded from the memory M 58   a.    
     Then, in Step P 128 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during doctor roller throw-off. If the answer is N, the program returns to Step P 126  mentioned above. If the answer is Y, Step P 129  is executed in which the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0. Then, in Step P 130 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 131 , the amount of movement of the left side of the doctor roller is loaded from the memory M 74 . Then, in Step P 132 , it is determined whether the amount of movement of the left side of the doctor roller is equal to 0. If the answer is Y in Step P 132 , the program shifts to Step P 137  to be described later. If the answer is N in Step P 132 , the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 1 in Step P 133 . 
     Then, in Step P 134 , it is determined whether the amount of movement of the left side of the doctor roller is larger than 0. If the answer is Y in Step P 134 , Step P 135  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 136 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program proceeds to the aforementioned Step P 137 . 
     If the answer is N in the above Step P 134 , Step P 138  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 139 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program shifts to the aforementioned Step P 137 . 
     Then, in the above Step P 137 , the amount of movement of the right side of the doctor roller is loaded from the memory M 75 . Then, in Step P 140 , it is determined whether the amount of movement of the right side of the doctor roller is equal to 0. If the answer is Y in Step P 140 , the program shifts to Step P 145  to be described later. If the answer is N in Step P 140 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 1 in Step P 141 . 
     Then, in Step P 142 , it is determined whether the amount of movement of the right side of the doctor roller is larger than 0. If the answer is Y in Step P 142 , Step P 143  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 144 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program proceeds to Step P 145 . 
     If the answer is N in the above Step P 142 , Step P 146  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 147 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program shifts to the aforementioned Step P 145 . 
     Subsequently, in Step P 145 , the value of the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is loaded. Then, in Step P 148 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the left side is equal to 0. If the answer is Y in Step P 148 , the value of the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is loaded in Step P 149 . If the answer is N in Step P 148 , the program shifts to Step P 152  to be described later. 
     Then, in Step P 150 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the right side is equal to 0. If the answer is Y in Step P 150 , outputting of the enabling signal to the counter  76   a  for counting the total number of revolutions during doctor roller throw-on is stopped in Step P 151 , and the program returns to Step P 119 . If the answer is N in Step P 150 , the aforementioned Step P 152  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor roller, and store it into the memory M 62   a.    
     Then, in Step P 153 , the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a . Then, in Step P 154 , it is determined whether the count value of the counter for detecting the current position of the left side of the doctor roller is equal to the throw-off position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 155 , and the program proceeds to Step P 156 . If the answer is N, the program directly shifts to Step P 156 . 
     Then, in the above Step P 156 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 157 , the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a.    
     Then, in Step P 158 , it is determined whether the count value of the counter  72   a  for detecting the current position of the right side of the doctor roller is equal to the throw-off position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with in Step P 159 , and the program returns to Step P 145 . If the answer is N, the program directly returns to Step P 145 . 
     In accordance with the above-described motion flow, when the doctor roller throw-on and throw-off automatic control switch  52   a  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is OFF, the doctor roller  90  is moved to the throw-off position. 
     Then, in Step P 160  shifted from the aforementioned Step P 120 , the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 64   a . Then, in Step P 161 , the count value is loaded from the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, and stored into the memory M 65   a.    
     Then, in Step P 162 , the correction amount (count value of the counter) of the doctor roller position is obtained from the count value of the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, with the use of the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position, and this correction amount is stored into the memory M 66   a . Then, in Step P 163 , the reference retreat position (count value of the counter) of the doctor roller is loaded from the memory M 53   a.    
     Then, in Step P 164 , the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 66   a . Then, in Step P 165 , the correction amount (count value of the counter) of the doctor roller position is added to the reference retreat position (count value of the counter) of the doctor roller to compute the retreat position (count value of the counter) of the doctor roller, which is stored into the memory M 67   a.    
     Then, in Step P 166 , the count value is loaded from the counter  68   a  for detecting the current position of the left side of the doctor roller, and stored into the memory M 62   a . Then follows Step P 167  in which the count value of the counter for detecting the current position of the left side of the doctor roller is subtracted from the retreat position (count value of the counter) of the doctor roller to compute the amount of movement of the left side of the doctor roller, which is stored into the memory M 74 . 
     Then, in Step P 168 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then follows Step P 169  in which the count value of the counter for detecting the current position of the right side of the doctor roller is subtracted from the retreat position (count value of the counter) of the doctor roller to compute the amount of movement of the right side of the doctor roller, which is stored into the memory M 75 . 
     Then, in Step P 170 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 171 , the rotation phase of the rotary screen cylinder during doctor roller throw-on is loaded from the memory M 69   a.    
     Then, in Step P 172 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during doctor roller throw-off. If the answer is N, the program returns to Step P 170  mentioned above. If the answer is Y, Step P 173  is executed in which the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0. Then, in Step P 174 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 175 , the amount of movement of the left side of the doctor roller is loaded from the memory M 74 . Then, in Step P 176 , it is determined whether the amount of movement of the left side of the doctor roller is equal to 0. If the answer is Y in Step P 176 , the program shifts to Step P 181  to be described later. If the answer is N in Step P 177 , the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 1 in Step P 177 . 
     Then, in Step P 178 , it is determined whether the amount of movement of the left side of the doctor roller is larger than 0. If the answer is Y in Step P 178 , Step P 179  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 180 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program proceeds to Step P 181 . 
     If the answer is N in Step P 178 , Step P 182  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 183 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program shifts to the aforementioned Step P 181 . 
     Then, in the above Step P 181 , the amount of movement of the right side of the doctor roller is loaded from the memory M 75 . Then, in Step P 184 , it is determined whether the amount of movement of the right side of the doctor roller is equal to 0. If the answer is Y in Step P 184 , the program shifts to Step P 189  to be described later. If the answer is N in Step P 184 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 1 in Step P 185 . 
     Then, in Step P 186 , it is determined whether the amount of movement of the right side of the doctor roller is larger than 0. If the answer is Y in Step P 186 , Step P 187  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 188 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program proceeds to Step P 189 . 
     If the answer is N in Step P 186 , Step P 190  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 191 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program shifts to the aforementioned Step P 189 . 
     Subsequently, in the above Step P 189 , the value of the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is loaded. Then, in Step P 192 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the left side is equal to 0. If the answer is Y in Step P 192 , the value of the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is loaded in Step P 193 . If the answer is N, the program shifts to Step P 196  to be described later. 
     Subsequently, in Step P 194 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the right side is equal to 0. If the answer is Y, Step P 195  is executed to stop the outputting of an enabling signal to the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, and the program shifts to Step P 204  to be described later. If the answer is N, the aforementioned Step P 196  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor roller, and store it into the memory M 62   a.    
     Then, in Step P 197 , the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 67   a . Then, in Step P 198 , it is determined whether the count value of the counter for detecting the current position of the left side of the doctor roller is equal to the retreat position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 199 , and the program proceeds to Step P 200 . If the answer is N, the program directly shifts to Step P 200 . 
     Then, in the aforementioned Step P 200 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 201 , the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 67   a.    
     Then, in Step P 202 , it is determined whether the count value of the counter  72   a  for detecting the current position of the right side of the doctor roller is equal to the retreat position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0 in Step P 203 , and the program returns to Step P 189 . If the answer is N, the program directly returns to Step P 189 . 
     In accordance with the above-described motion flow, when the doctor roller throw-on and throw-off automatic control switch  52   a  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the doctor roller  90  is moved to the predetermined retreat position when it opposes the notch  13   b  of the impression cylinder  13 . 
     Then, in Step P 204  shifted from the aforementioned Step P 195 , the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 64   a . Then, in Step P 205 , the count value is loaded from the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, and stored into the memory M 65   a.    
     Then, in Step P 206 , the correction amount (count value of the counter) of the doctor roller position is obtained from the count value of the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, with the use of the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position, and this correction amount is stored into the memory M 66   a . Then, in Step P 207 , the reference throw-on position (count value of the counter) of the doctor roller is loaded from the memory M 34   a.    
     Then, in Step P 208 , the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 66   a . Then, in Step P 209 , the correction amount (count value of the counter) of the doctor roller position is added to the reference throw-on position (count value of the counter) of the doctor roller to compute the printing position (count value of the counter) of the doctor roller, which is stored into the memory M 70   a.    
     Then, in Step P 210 , the count value is loaded from the counter  68   a  for detecting the current position of the left side of the doctor roller, and stored into the memory M 62   a . Then, in Step P 211 , the count value of the counter for detecting the current position of the left side of the doctor roller is subtracted from the printing position (count value of the counter) of the doctor roller to compute the amount of movement of the left side of the doctor roller, which is stored into the memory M 74 . 
     Then, in Step P 212 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 213 , the count value of the counter for detecting the current position of the right side of the doctor roller is subtracted from the printing position (count value of the counter) of the doctor roller to compute the amount of movement of the right side of the doctor roller, which is stored into the memory M 75 . 
     Then, in Step P 214 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 215 , the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder is loaded from the memory M 78 . 
     Then, in Step P 216 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder at the position of the rear end of the notch of the impression cylinder. If the answer is N, the program returns to Step P 214  mentioned above. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 217 . Subsequently, in Step P 218 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 219 , the amount of movement of the left side of the doctor roller is loaded from the memory M 74 . Then, in Step P 220 , it is determined whether the amount of movement of the left side of the doctor roller is equal to 0. If the answer is Y in Step P 220 , the program shifts to Step P 225  to be described later. If the answer is N in Step P 220 , the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 1 in Step P 221 . 
     Then, in Step P 222 , it is determined whether the amount of movement of the left side of the doctor roller is larger than 0. If the answer is Y in Step P 222 , Step P 223  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 224 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program proceeds to the aforementioned Step P 225 . 
     If the answer is N in Step P 222 , Step P 226  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 227 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program shifts to the aforementioned Step P 225 . 
     Then, in the above Step P 225 , the amount of movement of the right side of the doctor roller is loaded from the memory M 75 . Then, in Step P 228 , it is determined whether the amount of movement of the right side of the doctor roller is equal to 0. If the answer is Y in Step P 228 , the program shifts to Step P 233  to be described later. If the answer is N in Step P 228 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 1 in Step P 229 . 
     Then, in Step P 230 , it is determined whether the amount of movement of the right side of the doctor roller is larger than 0. If the answer is Y in Step P 230 , Step P 231  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 232 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program proceeds to the aforementioned Step P 233 . 
     If the answer is N in the above Step P 230 , Step P 234  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 235 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program shifts to the aforementioned Step P 233 . 
     Subsequently, in the above Step P 233 , the value of the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is loaded. Then, in Step P 236 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the left side is equal to 0. If the answer is Y in Step P 236 , the value of the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is loaded in Step P 237 . If the answer is N, the program shifts to Step P 239  to be described later. 
     Then, in Step P 238 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the right side is equal to 0. If the answer is Y in Step P 238 , the program shifts to Step P 247  to be described later. If the answer is N in Step P 238 , the aforementioned Step P 239  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor roller, and store it into the memory M 62   a.    
     Then, in Step P 240 , the printing position (count value of the counter) of the doctor roller is loaded from the memory M 70   a . Then, in Step P 241 , it is determined whether the count value of the counter for detecting the current position of the left side of the doctor roller is equal to the printing position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 242 , and the program proceeds to Step P 243 . If the answer is N in Step P 241 , the program directly shifts to Step P 243 . 
     Then, in the aforementioned Step P 243 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 244 , the printing position (count value of the counter) of the doctor roller is loaded from the memory M 70   a.    
     Then, in Step P 245 , it is determined whether the count value of the counter  72   a  for detecting the current position of the right side of the doctor roller is equal to the printing position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0 in Step P 246 , and the program returns to Step P 233 . If the answer is N in Step P 245 , the program directly returns to Step P 233 . 
     In accordance with the above-described motion flow, when the doctor roller throw-on and throw-off automatic control switch  52   a  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the doctor roller  90  is moved to the predetermined printing position when it enters the rotation phase of the rotary screen cylinder  11  corresponding to the position of the rear end of the notch of the impression cylinder  13 . 
     Then, in Step P 247  shifted from the aforementioned Step P 238 , the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 64   a . Then, in Step P 248 , the count value is loaded from the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, and stored into the memory M 65   a.    
     Then, in Step P 249 , the correction amount (count value of the counter) of the doctor roller position is obtained from the count value of the counter  76   a  for counting the total number of revolutions during doctor roller throw-on, with the use of the table of conversion from the total number of revolutions during doctor roller throw-on to the correction amount (count value of the counter) of the doctor roller position, and this correction amount is stored into the memory M 66   a . Then, in Step P 250 , the reference retreat position (count value of the counter) of the doctor roller is loaded from the memory M 53   a.    
     Then, in Step P 251 , the correction amount (count value of the counter) of the doctor roller position is loaded from the memory M 66   a . Then, in Step P 252 , the correction amount (count value of the counter) of the doctor roller position is added to the reference retreat position (count value of the counter) of the doctor roller to compute the retreat position (count value of the counter) of the doctor roller, which is stored into the memory M 67   a.    
     Then, Step P 253  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor roller, and store it into the memory M 62   a . Then, in Step P 254 , the count value of the counter for detecting the current position of the left side of the doctor roller is subtracted from the retreat position (count value of the counter) of the doctor roller to compute the amount of movement of the left side of the doctor roller, which is stored into the memory M 74 . 
     Then, Step P 255  is executed to load the count value from the counter  72   a  for detecting the current position of the right side of the doctor roller, and store it into the memory M 63   a . Then, in Step P 256 , the count value of the counter for detecting the current position of the right side of the doctor roller is subtracted from the retreat position (count value of the counter) of the doctor roller to compute the amount of movement of the right side of the doctor roller, which is stored into the memory M 75 . 
     Then, in Step P 257 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 258 , the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder is loaded from the memory M 71 . 
     Then, in Step P 259 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder at the position of the leading end of the notch of the impression cylinder. If the answer is N, the program returns to Step P 257  mentioned above. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 260 . Then, in Step P 261 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 262 , the amount of movement of the left side of the doctor roller is loaded from the memory M 74 . Then, in Step P 263 , it is determined whether the amount of movement of the left side of the doctor roller is equal to 0. If the answer is Y in Step P 263 , the program shifts to Step P 268  to be described later. If the answer is N in Step P 263 , the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 1 in Step P 264 . 
     Then, in Step P 265 , it is determined whether the amount of movement of the left side of the doctor roller is larger than 0. If the answer is Y in Step P 265 , Step P 266  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 267 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program proceeds to the aforementioned Step P 268 . 
     If the answer is N in the above Step P 265 , Step P 269  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 270 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program shifts to the aforementioned Step P 268 . 
     Then, in the aforementioned Step P 268 , the amount of movement of the right side of the doctor roller is loaded from the memory M 75 . Then, in Step P 271 , it is determined whether the amount of movement of the right side of the doctor roller is equal to 0. If the answer is Y in Step P 271 , the program shifts to Step P 276  to be described later. If the answer is N in Step P 271 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 1 in Step P 272 . 
     Then, in Step P 273 , it is determined whether the amount of, movement of the right side of the doctor roller is larger than 0. If the answer is Y in Step P 273 , Step P 274  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 275 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program proceeds to the aforementioned Step P 276 . 
     If the answer is N in the above Step P 273 , Step P 277  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 278 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program shifts to the aforementioned Step P 276 . 
     Subsequently, in the aforementioned Step P 276 , the value of the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is loaded. Then, in Step P 279 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the left side is equal to 0. If the answer is Y in Step P 279 , the value of the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is loaded in Step P 280 . If the answer is N in Step P 279 , the program shifts to Step P 283  to be described later. 
     Subsequently, in Step P 281 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the right side is equal to 0. If the answer is Y in Step P 281 , Step P 282  is executed to determine whether the cylinder engagement signal for the rotary screen cylinder is ON. If the answer is Y, the program returns to Step P 204 . If the answer is N, the program returns to Step P 121 . 
     If the answer is N in the aforementioned Step P 281 , the count value is loaded from the counter  68   a  for detecting the current position of the left side of the doctor roller, and stored into the memory M 62   a , in the aforementioned Step P 283 . 
     Then, in Step P 284 , the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 67   a . Then, in Step P 285 , it is determined whether the count value of the counter for detecting the current position of the left side of the doctor roller is equal to the retreat position (count value of the counter) of the doctor roller. If the answer is. Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 286 , and the program proceeds to Step P 287 . If the answer is N, the program directly shifts to Step P 287 . 
     Then, in the aforementioned Step P 287 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 288 , the retreat position (count value of the counter) of the doctor roller is loaded from the memory M 67   a.    
     Then, in Step P 289 , it is determined whether the count value of the counter  72   a  for detecting the current position of the right side of the doctor roller is equal to the retreat position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0 in Step P 290 , and the program returns to Step P 276 . If the answer is N, the program directly returns to Step P 276 . 
     In accordance with the above-described motion flow, when the doctor roller throw-on and throw-off automatic control switch  52   a  is ON and the cylinder engagement signal for the rotary screen cylinder  11  is ON, the doctor roller  90  is moved to the predetermined retreat position when it enters the rotation phase of the rotary screen cylinder  11  corresponding to the position of the leading end of the notch of the impression cylinder  13 . 
     Then, in Step P 291  shifted from the aforementioned Step P 119 , the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a.    
     Then, Step P 292  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor roller, and store it into the memory M 62   a . Then, in Step P 293 , the count value of the counter for detecting the current position of the left side of the doctor roller is subtracted from the throw-off position (count value of the counter) of the doctor roller to compute the amount of movement of the left side of the doctor roller, which is stored into the memory M 74 . 
     Then, Step P 294  is executed to load the count value from the counter  72   a  for detecting the current position of the right side of the doctor roller, and store it into the memory M 63   a . Then, in Step P 295 , the count value of the counter for detecting the current position of the right side of the doctor roller is subtracted from the throw-off position (count value of the counter) of the doctor roller to compute the amount of movement of the right side of the doctor roller, which is stored into the memory M 75 . 
     Then, in Step P 296 , the count value is loaded from the counter  74  for detecting the rotation phase of the rotary screen cylinder, and stored into the memory M 68 . Then, in Step P 297 , the rotation phase of the rotary screen cylinder during doctor roller throw-off is loaded from the memory M 58   a.    
     Then, in Step P 298 , it is determined whether the count value of the counter for detecting the rotation phase of the rotary screen cylinder is equal to the rotation phase of the rotary screen cylinder during doctor roller throw-off. If the answer is N, the program returns to Step P 296  mentioned above. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 299 . Then, in Step P 300 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0. 
     Then, in Step P 301 , the amount of movement of the left side of the doctor roller is loaded from the memory M 74 . Then, in Step P 302 , it is determined whether the amount of movement of the left side of the doctor roller is equal to 0. If the answer is Y in Step P 302 , the program shifts to Step P 307  to be described later. If the answer is N in Step P 302 , the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 1 in Step P 303 . 
     Then, in Step P 304 , it is determined whether the amount of movement of the left side of the doctor roller is larger than 0. If the answer is Y in Step P 304 , Step P 305  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 306 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program proceeds to the aforementioned Step P 307 . 
     If the answer is N in the aforementioned Step P 304 , Step P 308  is executed to compute the absolute value of the amount of movement of the left side of the doctor roller from the amount of movement of the left side of the doctor roller, and store it into the memory M 76 . Then, in Step P 309 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the left side of the doctor roller is outputted to the driver  66   a  for the stepping motor for adjusting the left side. Then, the program shifts to Step P 307  mentioned above. 
     Then, in the above Step P 307 , the amount of movement of the right side of the doctor roller is loaded from the memory M 75 . Then, in Step P 310 , it is determined whether the amount of movement of the right side of the doctor roller is equal to 0. If the answer is Y in Step P 310 , the program shifts to Step P 315  to be described later. If the answer is N in Step P 310 , the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 1 in Step P 311 . 
     Then, in Step P 312 , it is determined whether the amount of movement of the right side of the doctor roller is larger than 0. If the answer is Y in Step P 312 , Step P 313  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 314 , a normal rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program proceeds to the aforementioned Step P 315 . 
     If the answer is N in the aforementioned Step P 312 , Step P 316  is executed to compute the absolute value of the amount of movement of the right side of the doctor roller from the amount of movement of the right side of the doctor roller, and store it into the memory M 77 . Then, in Step P 317 , a reverse rotation pulse outputting command corresponding to the absolute value of the amount of movement of the right side of the doctor roller is outputted to the driver  70   a  for the stepping motor for adjusting the right side. Then, the program shifts to the aforementioned Step P 315 . 
     Subsequently, in the above Step P 315 , the value of the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is loaded. Then, in Step P 318 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the left side is equal to 0. If the answer is Y in Step P 318 , the value of the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is loaded in Step P 319 . If the answer is N in Step P 318 , the program shifts to Step P 322  to be described later. 
     Subsequently, in Step P 320 , it is determined whether the value of the memory for storing the presence or absence of rotation of the stepping motor for adjusting the right side is equal to 0. If the answer is Y in Step P 320 , Step P 321  is executed to stop the outputting of the enabling signal to the counter  76   a  for counting the total number of revolutions during doctor roller throw-on. Then, the program returns to Step P 1 . If the answer is N in Step P 320 , the aforementioned Step P 322  is executed to load the count value from the counter  68   a  for detecting the current position of the left side of the doctor-roller, and store it into the memory M 62   a.    
     Then, in Step P 323 , the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a . Then, in Step P 324 , it is determined whether the count value of the counter for detecting the current position of the left side of the doctor roller is equal to the throw-off position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 60   a  for storing the presence or absence of rotation of the stepping motor for adjusting the left side is overwritten with 0 in Step P 325 , and the program proceeds to Step P 326 . If the answer is N in Step P 324 , the program directly shifts to Step P 326 . 
     Then, in the aforementioned Step P 326 , the count value is loaded from the counter  72   a  for detecting the current position of the right side of the doctor roller, and stored into the memory M 63   a . Then, in Step P 327 , the throw-off position (count value of the counter) of the doctor roller is loaded from the memory M 54   a.    
     Then, in Step P 328 , it is determined whether the count value of the counter  72   a  for detecting the current position of the right side of the doctor roller is equal to the throw-off position (count value of the counter) of the doctor roller. If the answer is Y, the memory M 61   a  for storing the presence or absence of rotation of the stepping motor for adjusting the right side is overwritten with 0 in Step P 329 , and the program returns to Step P 315 . If the answer is N in Step P 328 , the program directly returns to Step P 315 . 
     In accordance with the above-described motion flow, when the doctor roller throw-on and throw-off automatic control switch  52   a  is brought to the OFF-state, the doctor roller  90  is moved to the throw-off position. 
     According to the present Embodiment 2, as described above, the throw-on position of the doctor roller  90  during printing is preset, based on the type of the material W to be printed (i.e., difference in the material, e.g., paper, cloth, film or corrugated board), in conformity with the thickness of the material to be printed, the material for the screen printing forme  11   c , the thickness of the screen printing forme, the open area rate of the screen printing forme, the mesh size of the screen printing forme  11   c , the viscosity of ink, the yield value of ink, the type of the pigment of ink, the material for the doctor roller, and the surface hardness of the doctor roller. Thus, burden on the operator can be lessened by automation, and the rate of operation can be increased and the occurrence of wasted paper can be curtailed by shortening the period of time until normal printing products can be obtained by printing. 
     In the present Embodiment 2, moreover, even when the doctor roller  90  is located at a position where it opposes the notch  13   b  of the impression cylinder  13  (i.e., the retreat position), the outer peripheral surface of the doctor roller  90  does not leave the inner peripheral surface of the screen printing forme  11   c , and only its pressure exerted on this surface (i.e., pressing force) is rendered lower than the pressure during printing. Thus, the screen printing forme  11   c  is prevented from being pushed into the notch  13   b  of the impression cylinder  13  by the doctor roller  90  and damaged thereby, and there is no ink leaking out toward the downstream side in the rotating direction of the screen printing forme  11   c , so that deterioration of printing quality is prevented. 
     That is, the following problems are avoided: Because of leaks of ink toward the downstream side in the rotating direction of the screen printing forme  11   c , the amount of ink remaining in front of the doctor roller  90  becomes small to decrease the ink density at the start of printing. The ink leaking out toward the downstream side leaks out through the holes of the picture pattern portion under a centrifugal force during high speed rotation, adheres to outside portions of the holes, and sticks to the outside of the picture pattern portion during printing, thereby deteriorating printing quality. 
     In the present Embodiment 2, moreover, the control pressure may be switched using a hydraulic or pneumatic actuator instead of the stepping motor  36 Aa for adjusting the left side and the stepping motor  36 Bb for adjusting the right side. Furthermore, the motors  36 Aa and  36 Bb are disposed on the right side and the left side. However, there may be adopted a configuration in which a one-sided motor moves the right and left sides, for example, by connecting the right and left sides by a lever mechanism. 
     The invention thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.