Abstract:
A liquid transfer method includes the steps of conveying a sheet by holding the sheet by a transport cylinder, and transferring a liquid to one surface of the sheet by a transfer cylinder opposing the transport cylinder and transferring the liquid to the other surface of the sheet by the transport cylinder. The step of transferring includes the step of positioning an edge of a region on one surface of the sheet, downstream in a sheet convey direction, where the liquid is to be transferred, upstream in the sheet convey direction of an edge of a region on the other surface of the sheet, downstream in the sheet convey direction, where the liquid is to be transferred. A liquid transfer apparatus is also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a liquid transfer method and liquid transfer apparatus which transfer a liquid such as varnish or ink to the two surfaces of a sheet. 
     As a conventional liquid transfer apparatus, one disclosed in Japanese Patent Laid-Open No. 2003-182031 is available. This liquid transfer apparatus comprises a first blanket cylinder (transport cylinder) which holds and conveys a sheet by gripping its one edge, and a second blanket cylinder which opposes the first blanket cylinder. As the sheet passes between the first and second blanket cylinders, varnish is transferred from the second blanket cylinder to the obverse of the sheet, thus coating the obverse of the sheet. Simultaneously, the printing pressure of the second blanket cylinder transfers the varnish from the first blanket cylinder to the reverse of the sheet, thus coating the reverse of the sheet as well. 
     In the conventional apparatus described above which transfers the liquid to the sheet, when performing overall coating on the two surfaces of the sheet, the following problem occurs. Note that overall coating refers to coating of the sheet entirely excluding margins reserved on the leading, trailing, left, and right edges of the sheet. When overall coating is to be performed on a sheet printed with ink, overall coating refers to coating that completely covers the images and register marks printed with the ink. 
     When performing overall coating on the two surfaces of the sheet, immediately after the leading edge of the sheet passes between the first and second blanket cylinders, the leading edge of the obverse of the sheet undesirably adheres to the second blanket cylinder due to the tackiness of the varnish on the obverse of the sheet, so that the leading edge of the reverse of the sheet is sometimes pulled to be separate from the surface of the first blanket cylinder. Then, transfer nonuniformities occur in the varnish transferred from the first blanket cylinder to the reverse of the sheet to degrade the coating quality. This problem also arises in a printing apparatus which prints using high-viscosity ink. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to solve this problem and has as its object to prevent the sheet from separating from the transport cylinder, thus improving the transfer quality. 
     In order to achieve the above object, according to an aspect of the present invention, there is provided a liquid transfer method comprising the steps of conveying a sheet by holding the sheet by a transport cylinder and transferring a liquid to one surface of the sheet by a transfer cylinder opposing the transport cylinder, and transferring the liquid to the other surface of the sheet by the transport cylinder, wherein the step of transferring comprises the step of positioning an edge of a region on one surface of the sheet, downstream in a sheet convey direction, where the liquid is to be transferred, upstream in the sheet convey direction of an edge of a region on the other surface of the sheet, downstream in the sheet convey direction, where the liquid is to be transferred. 
     According to another aspect of the present invention, there is also provided a liquid transfer apparatus comprising a first transfer cylinder which transfers a liquid to one surface of a sheet, and a transport cylinder which opposes the first transfer cylinder, holds and conveys the sheet, and transfers the liquid to the other surface of the sheet, wherein the first transfer cylinder and the transport cylinder transfer the liquid such that an edge of a region on one surface of the sheet, downstream in a sheet convey direction, where the liquid is to be transferred is located upstream in the sheet convey direction of an edge of a region on the other surface of the sheet, downstream in the sheet convey direction, where the liquid is to be transferred. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a coating unit in a printing press according to one embodiment of the present invention; 
         FIG. 2  is a side view of each of first and second phase adjustment devices; 
         FIG. 3  is a view seen from the line of an arrow III in  FIG. 2 ; 
         FIG. 4  is a side view of the main part to explain phase delay of an upper plate cylinder in the rotational direction with respect to an upper blanket cylinder; 
         FIG. 5  is a front view showing a mounted state of blankets which are to be mounted on the circumferential surface of the upper plate cylinder and that of a lower plate cylinder; 
         FIG. 6  is a sectional view taken along the line VI-VI of  FIG. 5 ; 
         FIG. 7  is an enlarged side view of an opposing portion of the upper blanket cylinder and a blanket cylinder when coating the obverse and reverse of a sheet; 
         FIG. 8  is a schematic side view showing a state in which the obverse and reverse of the sheet are coated; and 
         FIG. 9  is a schematic front view showing a state in which the obverse and reverse of the sheet are coated. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The embodiment of the present invention will be described with reference to the accompanying drawings. A case will be described with reference to  FIGS. 1 to 9  in which a liquid transfer apparatus according to the present invention is applied to a coating unit in a printing press. This coating unit can subject one or two surfaces of a sheet to overall coating, or partial coating to coat only a specific portion. A case will be described in which the sheet is to be subjected to overall coating. The definition of overall coating is as described above. 
     The coating unit will be briefly described with reference to  FIG. 1 . An upper plate cylinder  1  serves as a varnish supply cylinder (liquid supply cylinder) and is provided with a notch la, extending in the axial direction, in part of its circumferential surface. A first varnish supply device  2  is a first liquid supply means for supplying varnish to the upper plate cylinder  1 , and comprises an upper anilox roller  3  in contact with the upper plate cylinder  1  and a chamber coater  4  which supplies the varnish to the upper anilox roller  3 . The first varnish supply device  2  and upper plate cylinder  1  constitute a first varnish feeding device (first liquid feeding means) which supplies the varnish to the upper plate cylinder  1 . 
     An upper blanket cylinder  5  is a printing cylinder serving as a first transfer cylinder, and is in contact with the upper plate cylinder  1  and opposes a blanket cylinder  6  (to be described later). The upper blanket cylinder  5  is provided with a notch  5   a , extending in the axial direction, in part of its circumferential surface. The blanket cylinder  6  is a printing cylinder serving as a transport cylinder. The blanket cylinder  6  is provided with a pair of notches  6   a , extending in the axial direction, at positions that halve the circumferential surface of the blanket cylinder  6  in the circumferential direction. A gripper unit  7  (sheet holding means) which grips and holds the sheet is arranged in each notch  6   a.    
     A lower plate cylinder  8  serves as a second transfer cylinder in contact with the blanket cylinder  6 , and is provided with a notch  8   a , extending in the axial direction, in part of its circumferential surface. A second varnish supply device  9  is a second liquid supply means for supplying the varnish to the lower plate cylinder  8 , and comprises a lower anilox roller  10  in contact with the lower plate cylinder  8 , and a chamber coater  11  which supplies the varnish to the lower anilox roller  10 . The second varnish supply device  9  and lower plate cylinder  8  constitute a second varnish feeding device (second varnish feeding means) which supplies the varnish to the lower plate cylinder  8 . 
     The upper blanket cylinder  5  opposes the blanket cylinder  6 , downstream of an opposing position where an impression cylinder  13  of a printing unit  12  provided upstream of the coating unit opposes the blanket cylinder  6 , in the downstream rotational direction of the blanket cylinder  6 . The lower plate cylinder  8  opposes the blanket cylinder  6 , upstream of an opposing position where the impression cylinder  13  of the printing unit  12  opposes the blanket cylinder  6 , in the upstream rotational direction of the blanket cylinder  6 . 
     The varnish supplied from the chamber coater  4  to the upper anilox roller  3  is transferred to the upper blanket cylinder  5  through the upper plate cylinder  1 , so that the obverse of printed paper (sheet), passing through the opposing point (nip) where the upper blanket cylinder  5  opposes the blanket cylinder  6 , is coated. As the sheet passes the opposing position of the upper blanket cylinder  5  and blanket cylinder  6 , the reverse of the printed sheet is coated with the varnish, transferred from the lower plate cylinder  8  to the circumferential surface of the blanket cylinder  6 , by the printing pressure of the upper blanket cylinder  5 . The sheet with the coated reverse is gripping-changed to the gripper of a delivery chain  14  and conveyed to a sheet delivery device (not shown). 
     A first phase adjustment device (first phase adjusting means)  15 A provided to the upper plate cylinder  1  and a second phase adjustment device (second phase adjusting means)  15 B provided to the lower plate cylinder  8  will be described with reference to  FIGS. 2 and 3 . As the first and second phase adjustment devices  15 A and  15 B have the same structure, only the first phase adjustment device  15 A will be described, and the second phase adjustment device  15 B will be described where necessary. 
     Referring to  FIG. 2 , an end shaft  1   b  of the upper plate cylinder  1  is axially supported by an external metal member  17 , axially supported by a frame  16  of the printing press, through an internal metal member  18 . Bolts  20  fix an external gear  19  to the projecting end of the end shaft  1   b  projecting outside from the frame  16 . The external gear  19  meshes with an internal gear  21  (to be described later). 
     Outside the frame  16 , an almost triangular bracket  22  is attached to the frame  16  through a plurality of stays  23  to be parallel to the frame  16 . A stepped worm wheel  24  is rotatably fitted in a bearing hole  22   a  of the bracket  22 . A nut  25  threadably engaging with a threaded portion formed on the distal end of the worm wheel  24  presses a thrust bearing  26  (to be described later) against the bracket  22 . 
     The thrust bearing  26  and a thrust bearing  27  are interposed on the two sides of the bracket  22  to sandwich it. A screw shaft  28  with a flange is inserted in a hole  24   a  formed in the inner peripheral portion of the worm wheel  24 . A threaded plate  30  fixed to the worm wheel  24  with a bolt  29  threadably engages with the distal end of a threaded portion  28   a  of the screw shaft  28 . 
     A coupling  31  has the internal gear  21  described above on its inner circumferential surface, and a disc  32  is threadably mounted on its one open end. One end of the screw shaft  28  described above is fitted in the inner hole of the disc  32 . The flange of the screw shaft  28  and the nut  33  sandwich the disc  32 . The flange of the screw shaft  28 , the nut  33 , and the disc  32  clamp thrust bearings  34  and  35 . With this arrangement, the screw shaft  28  and coupling  31  are pivotal relative to each other while their movements in the axial directions are regulated. 
     A helical gear  36  is fixed to a flange  31   a  of the coupling  31  by a ring  37  and bolt  38 , and meshes with a drive side helical gear  39 . Rotation of the driving side is transmitted to the upper plate cylinder  1  through the helical gears  39  and  36 , internal gear  21 , and external gear  19 . Since the external gear  19  and internal gear  21  slidably mesh with each other and the internal gear  21  has a large face width, even when the coupling  31  moves in the axial direction, the external gear  19  and internal gear  21  do not disengage from each other. 
     A bearing box  40  with a box-like shape as shown in  FIG. 3  is fixed to the bracket  22  described above. A worm  42  meshing with the worm wheel  24  is axially mounted on a worm shaft  41  axially supported by the bearing box  40 . The worm shaft  41  is connected to a motor (not shown) through a joint  43 . 
     Another bracket  46  is fixed to the upper portion of the bracket  22 . A linear displacement type potentiometer  45  is fixed to the bracket  46 . The potentiometer  45  comprises a detection body  48  which is biased in the elongating direction by the spring force of a compression coil spring  47 . A press body  49  is fixed to the distal end of the screw shaft  28 . The upper end of the press body  49  is in contact with the detection body  48 . As will be described later, when the screw shaft  28  moves in the axial direction upon phase adjustment of the upper plate cylinder  1 , the press body  49  cooperates with the compression coil spring  47  to press the detection body  48 . The potentiometer  45  detects the forward/backward moving amount of the detection body  48 . The phase adjustment amount of the upper plate cylinder  1  is calculated from the forward/backward moving amount. A panel (not shown) displays the calculated phase adjustment amount. 
     In this arrangement, when the worm shaft  41  pivots to pivot the worm wheel  24 , thus pivoting the screw shaft  28 , the screw shaft  28  moves in the axial direction due to the screw function of the threaded portion  28   a . The coupling  31  and helical gear  36  which are integral with the screw shaft  28  in the axial direction also move in the axial direction. The upper plate cylinder  1  slightly pivots in the circumferential direction due to the helical function of the helical gears  36  and  39 , so that the phase of the upper plate cylinder  1  is adjusted with respect to the upper blanket cylinder  5 . Thus, as shown in  FIG. 4 , the phase of the upper plate cylinder  1  is delayed from that of the upper blanket cylinder  5  by δ. More specifically, the rotation start of that effective impression area  1   b  of the upper plate cylinder  1 , which is continuous to the notch  1   a , is positioned upstream of a rotation start of an effective impression area  5   b  of the upper blanket cylinder  5 , which is continuous to the notch  5   a , by δ in the rotational direction of the upper plate cylinder  1 . Similarly, when operating the second phase adjustment device  15 B, the lower plate cylinder  8  slightly pivots in the circumferential direction to adjust its phase with respect to the blanket cylinder  6 . 
     The mounting structures for blankets  63 A and  63 B which are mounted on the circumferential surface of the upper plate cylinder  1  and on that of the lower plate cylinder  8  will be described with reference to  FIGS. 5 and 6 . As the mounting structure for the upper plate cylinder  1  and that for the lower plate cylinder  8  are identical, only the mounting structure for the varnish supply cylinder blanket (blanket for a liquid supply cylinder)  63 A and a varnish supply cylinder sheet member (sheet member for a liquid supply cylinder)  65 A which are to be mounted on the upper plate cylinder  1  will be described, and the mounting structure for the second transfer cylinder blanket (blanket for a second transfer cylinder)  63 B and a second transfer cylinder sheet member (sheet member for a second transfer cylinder)  65 B which are to be mounted on the lower plate cylinder  8  will be described where necessary. 
     As shown in  FIG. 6 , the upper plate cylinder  1  is provided with a notch  51 , extending throughout the entire length of the cylinder, in its circumferential surface. A leading edge plate clamp (plate member holding device)  52  and trailing edge plate clamp (plate member holding device)  53  extend in the notch  51  in the axial direction of the cylinder  1  to be parallel to each other. The leading edge plate clamp  52  and trailing edge plate clamp  53  are respectively provided with bottom clamping rails  54   a  and  54   b  extending in the axial direction of the cylinder  1 . The bottom clamping rails  54   a  and  54   b  are respectively provided with gripping surfaces  55   a  and  55   b  and mouthpiece insertion grooves  56   a  and  56   b  on their upper surfaces. The mouthpiece insertion grooves  56   a  and  56   b  continue to the gripping surfaces  55   a  and  55   b , respectively. The bottom surfaces of the mouthpiece insertion grooves  56   a  and  56   b  are parallel to the gripping surfaces  55   a  and  55   b , respectively, and extend in the axial direction of the cylinder  1 . Spacers  57   a  and  57   b  are fixed to the bottom surfaces of the mouthpiece insertion grooves  56   a  and  56 , respectively. 
     Bolts  59   a  and  59   b  screwed into the upper portions of the bottom clamping rails  54   a  and  54   b  swingably support gripper boards  58   a  and  58   b , respectively. The gripper boards  58   a  and  58   b  are respectively provided with gripping surfaces  60   a  and  60   b  which oppose the gripping surfaces  55   a  and  55   b  of the bottom clamping rails  54   a  and  54   b , respectively. The distal ends of the gripping surfaces  60   a  and  60   b  cover the mouthpiece insertion grooves  56   a  and  56   b , respectively. Round rod-like cams  61   a  and  61   b  are in contact with the rear ends of the gripper boards  58   a  and  58   b , respectively. When the cams  61   a  and  61   b  are pivoted, the gripper boards  58   a  and  58   b  swing about the bolts  59   a  and  59   b  as swing centers, respectively. 
     A case in which the varnish supply cylinder blanket  63 A is to be mounted on the upper plate cylinder  1  (or a case in which the second transfer cylinder blanket  63 B is to be mounted on the lower plate cylinder  8 ) will be described. A mouthpiece  62   a  attached to one end of the varnish supply cylinder blanket  63 A (or second transfer cylinder blanket  63 B) is inserted in the mouthpiece insertion groove  56   a  of the bottom clamping rail  54   a . The cam  61   a  is pivoted so that the distal end of the gripper board  58   a  covers the mouthpiece insertion groove  56   a . Thus, the distal end of the gripper board  58   a  urges the mouthpiece  62   a  to fix it in the mouthpiece insertion groove  56   a.    
     The varnish supply cylinder blanket  63 A (or second transfer cylinder blanket  63 B) is wound around the circumferential surface of the upper plate cylinder  1  (or lower plate cylinder  8 ), and a mouthpiece  62   b  attached to the other end of the varnish supply cylinder blanket  63 A (or second transfer cylinder blanket  63 B) is inserted in the mouthpiece insertion groove  56   b  of the bottom clamping rail  54   b . The cam  61   b  is pivoted so that the distal end of the gripper board  58   b  covers the mouthpiece insertion groove  56   b . Thus, the distal end of the gripper board  58   b  urges the mouthpiece  62   b  to fix it in the mouthpiece insertion groove  56   b.    
     When the bottom clamping rail  54   b  slides toward the center of the notch  51 , that is, in the direction to tighten the varnish supply cylinder blanket  63 A (or second transfer cylinder blanket  63 B) to be close to the bottom clamping rail  54   a , the varnish supply cylinder blanket  63 A (or second transfer cylinder blanket  63 B) is tightened to come into tight contact with the circumferential surface of the cylinder  1 . 
     Referring to  FIG. 5 , the varnish supply cylinder sheet member  65 A is interposed between the varnish supply cylinder blanket  63 A and the circumferential surface of the upper plate cylinder  1 , and is a so-called blanket underlying member. The varnish with the same shape as the outer shape of the varnish supply cylinder sheet member  65 A is transferred to the obverse of the sheet, being conveyed by the blanket cylinder  6 , through the upper blanket cylinder  5 . More specifically, the varnish with the same width as a length W of the varnish supply cylinder sheet member  65 A in the widthwise direction is transferred to the obverse of the sheet, and the varnish with the same length as the circumferential length of the varnish supply cylinder sheet member  65 A is transferred to the obverse of the sheet. 
     The second transfer cylinder sheet member  65 B is interposed between the second transfer cylinder blanket  63 B and the circumferential surface of the lower plate cylinder  8 , and is a so-called blanket underlying member. The varnish with the same shape as the outer shape of the second transfer cylinder sheet member  65 B is transferred to the reverse of the sheet, being conveyed by the blanket cylinder  6 , through the blanket cylinder  6 . More specifically, the varnish with the same width as a length W of the second transfer cylinder sheet member  65 B in the widthwise direction is transferred to the reverse of the sheet, and the varnish with the same length as the circumferential length of the second transfer cylinder sheet member  65 B is transferred to the reverse of the sheet. 
     According to this embodiment, as shown in  FIG. 4 , the first phase adjustment device  15 A adjusts the phase of the upper plate cylinder  1  to be delayed from the phase of the upper blanket cylinder  5  by δ, and the second phase adjustment device  15 B adjusts the phase of the lower plate cylinder  8 . After the cylinder phases are adjusted in this manner, the first and second varnish feeding devices described above supply the varnish to the upper blanket cylinder  5  and blanket cylinder  6 , respectively. Thus, as shown in  FIG. 7 , an edge  82   a  of that region  82  of the upper blanket cylinder  5 , downstream in the rotational direction (on the side in a direction E), where varnish  71  is supplied to the upper blanket cylinder  5  is positioned more upstream, by a length α in the upstream rotational direction of the upper blanket cylinder  5 , of an edge  83   a  of a region  83  of the blanket cylinder  6 , downstream in the rotational direction (on the side in a direction F), where the varnish  71  is supplied to the blanket cylinder  6 . 
     In the sheet  70  that has passed between the upper blanket cylinder  5  and blanket cylinder  6 , as shown in  FIG. 8 , a leading (downstream in the sheet convey direction or in the direction of an arrow A) margin  70   a  of an obverse  70 A of the sheet  70  which is not coated with the varnish  71  becomes larger by a length α than a leading margin  70   b  of a reverse  70 B of the sheet  70  which is not coated with the varnish  71 . In other words, a leading edge  72   a  of a coating region  72  of the obverse  70 A of the sheet  70  is positioned on the trailing side (upstream in the sheet convey direction or in the direction of an arrow B) of a leading edge  73   a  of a coating region  73  of the reverse  70 B of the sheet  70  by the length α. 
     The adjustment ranges of the first and second phase adjustment devices  15 A and  15 B are set such that a minimum value L 1 min of the length of the leading margin  70   a  of the obverse  70 A of the sheet  70  which is adjusted by the first phase adjustment device  15 A becomes lager than a maximum value L 2 max of the length of the leading margin  70   b  of the reverse  70 B of the sheet  70  which is adjusted by the second phase adjustment device  15 B. Thus, no matter how the first and second phase adjustment devices  15 A and  15 B may be adjusted, the length of the leading margin  70   a  of the obverse  70 A of the sheet  70  does not become smaller than the length of the leading margin  70   b  of the reverse  70 B. Therefore, the conventional problem does not occur, as will be described later. 
     The lengths of the leading margins  70   a  and  70   b  refer to the lengths from a leading edge  70   c  of the sheet  70  to leading edges  72   a  and  73   a  of the coating regions (liquid transfer regions)  72  and  73 , respectively, in the sheet convey direction. The lengths of the trailing margins refer to the lengths from a trailing edge  70   d  of the sheet  70  to trailing edges  72   b  and  73   b  of the coating regions (liquid transfer regions)  72  and  73 , respectively, in the sheet convey direction. The left and right margin lengths refer to the lengths from left and right trailing edges  70   e  and  70   f  of the sheet  70  to left and right trailing edges  72   c  and  72   d  and left and right trailing edges  73   c  and  73   d  of the coating regions (liquid transfer regions)  72  and  73 , respectively, in the direction of sheet width. 
     According to this embodiment, the length of the varnish supply cylinder sheet member  65 A in the circumferential direction (the directions of the arrows A and B) is smaller than the length of the second transfer cylinder sheet member  65 B in the circumferential direction (the directions of the arrows A and B), so that the trailing edge  72   b  of the coating region  72  of the obverse  70 A of the sheet  70  is located closer to the leading side by a length β than the trailing edge  73   b  of the coating region  73  of the reverse  70 B of the sheet  70 . The circumferential direction of the varnish supply cylinder sheet member  65 A refers to the direction that corresponds to the circumferential direction of the upper plate cylinder  1  when the varnish supply cylinder sheet member  65 A is mounted on the upper plate cylinder  1 . Similarly, the circumferential direction of the second transfer cylinder sheet member  65 B refers to the direction that corresponds to the circumferential direction of the lower plate cylinder  8  when the second transfer cylinder sheet member  65 B is mounted on the lower plate cylinder  8 . 
     According to the present invention, as shown in  FIG. 9 , the length of the varnish supply cylinder sheet member  65 A in the widthwise direction (the direction perpendicular to the circumferential direction) is smaller than that of the second transfer cylinder sheet member  65 B in the widthwise direction (the direction perpendicular to the circumferential direction) such that the left and right (in the widthwise direction or directions of arrows C and D) edges  72   c  and  72   d  of the coating region  72  of the obverse  70 A of the sheet  70  are located within the sheet  70  to be inside the left and right (in the widthwise direction or the directions of arrows C and D) trailing edges  73   c  and  73   d  of the coating region  73  of the reverse  70 B of the sheet  70  each by a length γ than. The widthwise direction of the varnish supply cylinder sheet member  65 A refers to the direction that corresponds to the axial direction of the upper plate cylinder  1  when the varnish supply cylinder sheet member  65 A is mounted on the upper plate cylinder  1 . Similarly, the widthwise direction of the second transfer cylinder sheet member  65 B refers to the direction that corresponds to the axial direction of the lower plate cylinder  8  when the second transfer cylinder sheet member  65 B is mounted on the lower plate cylinder  8 . 
     Immediately after the sheet  70  passes through the nip between the upper blanket cylinder  5  and blanket cylinder  6 , the tackiness of the varnish on the obverse  70 A of the sheet  70  exerts a force to stick the sheet  70  to the upper blanket cylinder  5 . According to this embodiment, however, as shown in  FIG. 8 , when the leading edge  70   c  of the sheet  70  passes between the blanket cylinder  6  and upper blanket cylinder  5 , the varnish is applied to the reverse  70 B of the sheet  70 , prior to the obverse  70 A of the sheet  70 , starting from the portion closer to the leading edge  70   c . As coating of the reverse  70 B is started prior to the obverse  70 A of the sheet  70  in this manner, the tackiness of the varnish on the reverse  70 B of the sheet  70  serves to prevent the leading edge of the sheet  70  from separating from the blanket cylinder  6  to undesirably stick to the circumferential surface of the upper blanket cylinder  5 . As a result, the blanket cylinder  6  suppresses varnish nonuniformities in the coating region  73  of the reverse  70 B of the sheet  70 , thus improving the coating quality. 
     On the trailing edge side of the sheet  70 , the varnish is applied to the reverse  70 B of the sheet  70  even after it is applied to the obverse  70 A of the sheet  70 . Thus, after the trailing edge  70   d  of the sheet  70  passes between the blanket cylinder  6  and upper blanket cylinder  5 , the trailing edge of the obverse  70 A of the sheet  70  does not stick to the circumferential surface of the upper blanket cylinder  5 . Hence, the blanket cylinder  6  suppresses varnish nonuniformities in the coating region  73  of the reverse  70 B of the sheet  70 , thus improving the coating quality. 
     As the sheet  70  passes between the blanket cylinder  6  and upper blanket cylinder  5 , the sheet  70  is coated such that the left and right edges  72   c  and  72   d  of the coating region  72  of the obverse  70 A of the sheet  70  is located within the sheet  70  to be inside the left and right edges  73   c  and  73   d  of the coating region  73  of the reverse  70 B of the sheet  70  by the length γ. As the coating region  73  of the reverse  70 B of the sheet  70  is larger than the coating region  72  of the obverse  70 A of the sheet  70  in this manner, after the sheet  70  passes between the blanket cylinder  6  and upper blanket cylinder  5 , the left and right edges of the obverse  70 A of the sheet  70  do not stick to the circumferential surface of the upper blanket cylinder  5 . Thus, the blanket cylinder  6  suppresses varnish nonuniformities in the coating region  73  of the reverse  70 B of the sheet  70 , thus improving the coating quality. 
     According to this embodiment, varnish (coating liquid) is employed as the liquid to be transferred. The present invention can also be applied to ink with a comparatively high viscosity. Although the sheet to which the liquid is to be transferred is exemplified by paper sheet, the transfer target can be any other sheet. For example, a non-rigid sheet such as a synthetic resin film or vinyl film can be employed as the transfer target sheet. 
     In this embodiment, a phase signifies a position on the cylinder in the rotational direction and is expressed by an angle with respect to the reference position of the cylinder.