Patent Publication Number: US-2012044310-A1

Title: Position adjustment mechanism and recording apparatus

Description:
The entire disclosure of Japanese Patent Application No: 2010-183103, filed Aug. 18, 2010 is expressly incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a position adjustment mechanism and a recording apparatus. 
     2. Related Art 
     In general, as a recording apparatus in which a liquid is adhered to a recording medium and a recording processing is performed, an ink jet type printer is widely known in which ink (liquid) is ejected from each nozzle of a recording head mounted on a carriage to the recording medium and the printing is performed (for example, JP-A-2010-125832). In the above-described printer, in order to secure the printing accuracy, the position of the recording head with respect to the carriage is adjusted. That is, in the printer of JP-A-2010-125832, a sliding member which slides on a head unit (a recording portion) and defines the inclination angle of the head unit, and an adjustment eccentric cam which is engaged to the sliding member are provided. In addition, the inclination angle of the head unit is defined through the sliding member due to a fact that the adjustment eccentric cam is rotated. 
     However, in the printer of JP-A-2010-125832, after the inclination angle of the head unit is adjusted through the sliding member due to the rotation of the adjustment eccentric cam, the position of the sliding member is fixed by fixing screws (screws). Therefore, although the inclination angle of the head unit is held to an appropriate angle, the fixing position of the sliding member, which is fixed by the fixing screws, is separated from the adjustment eccentric cam. Thereby, the fixing position of the sliding member is deviated due to the fastening through the fixing screws, and there is a problem in that the inclination angle of the head unit may be deviated. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a position adjustment mechanism and a recording apparatus capable of accurately holding a first member and a second member in a state where a position of the second member with respect to the first member is adjusted. 
     According to aspect of the invention, there is provided a position adjustment mechanism that adjusts a position of a second member with respect to a first member, the position adjustment mechanism including: a cam that is provided in the first member so that a cam surface of the cam abuts the second member; and a fixing portion that is provided in a forming area of the cam surface in the first member and fixes the second member to the first member by screw in a state where the position of the second member with respect to the first member is adjusted by the cam. 
     According to the aspect of the invention, in the state where the position of the second member with respect to the first member is adjusted by the cam, when the second member is fixed by the screw to the fixing portion which is provided in the forming area of the cam surface of the cam in the first member, the abutment position of the cam surface of the cam and the fixing position fixed by the screw come very close to each other in the second member. Therefore, it is possible to accurately hold the first member and the second member in a state where the position of the second member with respect to the first member is adjusted. 
     In the position adjustment mechanism of the aspect of the invention, three cams may be provided, and each cam may be disposed so as to line up in a non-liner shape in positions which are different to each other in the first member. 
     According to the position adjustment mechanism of the aspect of the invention, it is possible to accurately adjust the position of the second member with respect to the first member by each cam. 
     In the position adjustment mechanism of the aspect of the invention, the cam may be annularly formed and the fixing portion may be disposed so that an outer peripheral surface of the fixing portion comes close to an inner peripheral surface of the cam. 
     According to the position adjustment mechanism of the aspect of the invention, since the second member is fastened to the first member in the fixing portion by the screw, even though the cam tends to fall inward, it is possible to support the cam from the inside by the fixing portion. 
     In the position adjustment mechanism of the aspect of the invention, the cam may be annularly formed and a rotary cam which is rotated about a shaft installed so as to cross to an axis direction of the screw in the outer peripheral surface of the cam. In addition, the position adjustment mechanism may be further provided with a bearing portion that is installed in the first member and supports the shaft, and the bearing portion may be disposed so that a surface of the cam side comes close to the outer peripheral surface of the cam. 
     According to the position adjustment mechanism of the aspect of the invention, since the second member is fastened to the first member by the screw in the fixing portion, even though the cam tends to fall outward, it is possible to support the cam from the outside by the bearing portion. 
     According to another aspect of the invention, there is provided a recording apparatus including: the adjustment mechanism of the above-described configuration; and a recording portion that performs a recording processing on a recording medium which is transported from the upstream side toward the downstream side, wherein the first member constitutes a carriage that is moved in a scanning direction intersecting the transport direction of the recording medium, the second member constitutes the recording portion, each cam is disposed at two positions that are separated along the scanning direction on the upstream side of the transport direction in the carriage, and at one position between the two positions in the scanning direction at the downstream side in the transport direction in the carriage, the shafts of the cams disposed in the two positions are extended along the scanning direction, and the shaft of the cam disposed in the one position is extended along the transport direction. 
     In general, since the carriage is supported so as to be movable in a guide shaft in which the end of the upstream side in the transport direction of the recording medium in the carriage is extended in the scanning direction, a space capable of installing components in a side surface of the guide shaft side in the carriage is not substantially provided. With regard to this, according to the recording apparatus of the aspect of the invention, since each member for rotating the cam shaft can be installed in the both side surfaces in the scanning direction in the carriage and the side surface of a side which is opposite to the guide shaft side in the carriage, each cam can be easily rotated by operating each member. 
     In the recording apparatus of the aspect of the invention, the recording portion may include a nozzle forming area of a plane shape in which the nozzle is formed so as to eject a liquid to the recording medium, and each cam may be disposed on the outside of the nozzle forming area in a direction crossing the nozzle forming area. 
     According to the recording apparatus of the aspect of the invention, it is possible to accurately adjust the position of the recording portion so that the nozzle forming area is parallel to a recording surface of the recording medium by each cam. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view showing an ink jet type printer of an embodiment. 
         FIG. 2  is an exploded perspective view showing a carriage and a recording unit which is mounted on the carriage in a state of removing an upper cover of the printer. 
         FIG. 3  is a schematic plan view showing a position relationship between the recording unit and the carriage in the printer. 
         FIG. 4  is an enlarged perspective view showing a main portion of an inner portion of the carriage. 
         FIG. 5  is an enlarged perspective view showing a main portion of an outer portion of the carriage. 
         FIG. 6  is a plan view showing a cam in the printer. 
         FIG. 7  is a perspective view of  FIG. 6 . 
         FIG. 8  is a side view of  FIG. 6 . 
         FIG. 9  is an enlarged main portion cross-section view showing a state when a recording unit is fixed to the carriage by screw in the printer. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, one embodiment in which the invention is exemplified by an ink jet type printer will be described with reference to the accompanying drawings. In addition, in the description below, “the front-back direction”, “the left-right direction”, and “the up-down direction” each indicate the front-back direction, the left-right direction, and the up-down direction which are indicated by arrows in  FIG. 1 . 
     As shown in  FIG. 1 , the ink jet type printer  11  as a recording apparatus includes a main body frame  12 . In the lower portion of the main body frame  12 , a supporting frame  13  is extended and installed along the left-right direction which is the longitudinal direction of the main body frame  12 . On the supporting frame  13 , a recording sheet P serving as a recording medium is transported by a sheet-feeding mechanism (not shown) along a direction (a transport direction: a secondary scanning direction) which faces from a backward side being the upstream side to a forward side being the downstream side. 
     In the upside of the supporting frame  13  in the main body frame  12 , a main guide shaft  14  is extended and installed along the longitudinal direction (the left-right direction) of the supporting frame  13 . Moreover, in the upside of the main guide shaft  14  in the main body frame  12 , a secondary guide shaft  15  is extended and installed in parallel to the main guide shaft  14 . In the main guide shaft  14 , a carriage  16  as a first member is supported so as to reciprocate along an axis direction (the left-right direction) of the main guide shaft  14 . 
     That is, a pair of guide portions  16   a  (refer to  FIG. 3 ), which are each installed in the left and the right, are provided in a lower portion of a rear surface of the carriage  16 . Moreover, the main guide shaft  14  is slidably fitted to each guide portion  16   a . In addition, an engaging portion  16   b , which is slidably engaged to the secondary guide shaft  15  from the rear side of the secondary guide shaft  15 , is provided in an upper portion of a rear end of the carriage  16 . Moreover, the engaging portion  16   b  abuts the secondary guide shaft  15  while always applying load to the secondary guide shaft  15  due to the weight of the carriage  16  itself. 
     In a position of the slight upside of both ends of the main guide shaft  14  in the main frame  12 , a driving pulley  17   a  and a driven pulley  17   b  are rotatably supported. An output shaft of a carriage motor  18  is connected to the driving pulley  17   a  and the carriage motor  18  serves as a driving source when reciprocating the carriage  16  along the main guide shaft  14 . 
     In addition, an endless timing belt  19  is hung between both pulleys  17   a  and  17   b , and a portion of the endless timing belt  19  is connected to the carriage  16 . Therefore, the carriage  16  is reciprocated in the left-right direction (a primary scanning direction) via the endless timing belt  19  by the driving force of the carriage motor  18  while being guided in the main guide shaft  14  and the secondary guide shaft  15 . 
     As shown in  FIGS. 1 and 2 , the carriage  16  is formed in an approximately rectangular frame shape, and an upper cover  16   d  is detachably attached to the upside of the carriage  16 . Moreover, a recording head unit  20  is supported (accommodated) in the inner portion of the carriage  16 , and the recording head unit  20  serves as a recording portion which constitutes a second member. The recording head unit  20  includes a sub-carriage  20   a  of an approximately rectangular frame shape and a recording head  20   b  which is attached to the inside of the sub-carriage  20   a.    
     The lower surface of the recording head  20   b  is constituted from a nozzle forming area R of a plane shape in which a plurality nozzles N (refer to  FIG. 3 ) is opened. In addition, an ink tank  21 , which is charged with inks of each color in the inner portion thereof, is disposed at the lower left side of the main body frame  12 . The ink tank  21  is connected to the recording head unit  20 , which is supported to the carriage  16 , via a flexible ink supply tube  22 . Therefore, the inks of each color in the ink tank  21  are supplied to the recording head unit  20  via the ink supply tube  22 . 
     In addition, the carriage  16  is reciprocated in the left-right direction (the primary scanning direction), which is perpendicular to the transport direction of the recording sheet P, along the main guide shaft  14 . At the same time, the inks of each color, which are supplied from the ink tank  21  to the recording head unit  20 , are ejected to the fed recording sheet P from each of the nozzles N of the recording head  20   b  (refer to  FIG. 3 ) to the supporting frame  13 , and therefore, printing is performed. 
     Next, a configuration of the carriage  16  will be described. 
     As shown in  FIGS. 2 and 3 , when the carriage  16  supports the recording head unit  20 , the carriage  16  exposes a recording head  20   b  to an opening  23  of the bottom in the carriage  16 . On both the left side and right side of the carriage  16  which interposes the opening  23  on the rear end side of the bottom in the carriage  16  and a center portion in the left-right direction on the front end side of the bottom in the carriage  16 , rotary cams  24  for adjusting the position of the recording head unit  20  with respect to the carriage  16  are each rotatably disposed. 
     That is, each cam  24  is disposed in two positions which are separated along the primary scanning direction on the upstream side of the transport direction of the recording sheet P (refer to  FIG. 1 ) in the carriage  16 . In addition, each cam  24  is disposed in one position which is between the two positions in the primary scanning direction on the downstream side of the transport direction of the recording sheet P in the carriage  16 . In other words, in the outer side of the opening  23  in the bottom within the carriage  16 , three cams  24  are each disposed so as to draw (line up in a non-linear shape) a triangle in planar view when linearly connecting the cams  24  to one another. Therefore, each cam  24  is disposed on the outside of the nozzle forming area R in the up-down direction which is perpendicular to the nozzle forming area R. 
     Here, a configuration of the cam  24  will be described with reference to  FIGS. 6 to 8 . 
     First, in  FIGS. 6 to 8 , the longitudinal direction of the cam  24  is given as the X-direction, the lateral direction of the cam  24  is given as the Y-direction, and the thickness direction of the cam  24  is given as the Z-direction. 
     As shown in  FIGS. 6 to 8 , the cam  24  includes an opening  24   a  in the inner portion of the cam and is formed in an annularly rectangular shape in planar view. A front surface (a surface of one side) of the cam  24  and a rear surface (a surface of the other one side) of the cam  24  each become cam surfaces  25 , and the front surface and the rear surface of each cam surface  25  are symmetric to each other. In each cam surface  25 , a center portion in the X-direction is expanded outward in the Z-direction and become an arc portion  25   a  which constitutes an arc-shaped surface. In addition, each cam surface  25  is inclined so that the thickness of the cam  24  gradually decreases from the arc portion  25   a  to both ends in the X-direction, and becomes flat surface  25   b.    
     In a position which is slightly deviated in the X-direction from the center portion of both side surfaces (outer peripheral surfaces) in the Y-direction of the cam  24 , shafts  26  serving as center in the rotation of each cam  24  are each protruded and installed in the Y-direction so as to be opposite to each other. That is, each cam  24  becomes an eccentric cam in which each shaft  26  is eccentric. In the tip of the shaft  26  of one side of each shaft  26 , a lever member  27  for rotating the cam  24  about the shaft  26  is installed. That is, in the tip of the shaft  26  of one side of each shaft  26 , one end of the shaft  26  is connected to one side surface  27   a  of the lever member  27  of an approximately rectangular plate shape which is extended in the X-direction. 
     In a position which is slightly nearer to the other end side from the center portion in the X-direction in one side surface  27   a  of the lever member  27 , a guide piece  28  is protruded and installed. Moreover, the tip portion of the guide piece  28  is formed in an L-shape so as to be perpendicularly bent to the cam  24  side in the X-direction. In the other end portion in the X-direction in the one side surface  27   a  of the lever member  27 , an approximately elliptical protrusion  29  is installed. In addition, in the other end in the X-direction of the lever member  27 , a handle  30  is extended and installed so as to grasp the lever member  27  when rotating the cam  24  through the lever member  27 . The handle  30  is extended and installed toward the side which is opposite to the cam  24  side in the Y-direction. 
     As shown in  FIGS. 2 and 3 , each cam  24  is disposed so as to be adjacent to a peripheral wall  16   c  of the carriage  16 . In addition, penetration holes  31  each are formed in the peripheral wall  16   c , and the shaft  26  of the one side in which the lever member  27  of each cam  24  is installed is inserted into the penetration holes  31 . In addition, a lower end portion of each penetration holes  31  becomes a bearing portion  32  (refer to  FIG. 5 ), and the bearing portion  32  is formed in a U-shape and supports the shaft  26  of the one side in which the lever member  27  of each cam  24  is installed. In addition, the lever member  27  of each cam  24  is extended along the outside of the peripheral wall  16   c  of the carriage  16 . 
     As shown in  FIGS. 2 to 5 , a bearing plate  33  each is erected in a position which faces each bearing portion  32  by interposing each cam  24  in the carriage  16 . Each bearing portion  34  is installed in an upper end portion of each bearing plate  33 , and the bearing portion  34  is formed in a U-shape and supports the shaft  26  of the other one side in which the lever member  27  of each cam  24  is not installed. In this case, each bearing portion  32  and each bearing portion  34  correspond to each other in the axis direction of the corresponding cam  24 . Therefore, each cam  24  is disposed in the carriage  16  in a state where each shaft  26  is supported by each bearing portion  32  and each bearing portion  34 . 
     In this case, in the peripheral wall  16   c  in which each bearing portion  32  is installed and each bearing plate  33  in which each bearing portion  34  is installed, the surface of each cam  24  side of the peripheral wall  16   c  and each bearing plate  33  come close to the surface (the outer peripheral surface) in which each shaft  26  is installed in each cam  24 . Moreover, in this case, two cams  24 , which are disposed in the rear end side in the carriage  16  among the cams  24 , are disposed so that each shaft  26  of the two cams  24  is horizontally extended along the left-right direction. In addition, one cam  24 , which is disposed in the front end side in the carriage  16  among the cams  24 , is disposed so that each shaft  26  of the one cam  24  is horizontally extended along the front-back direction. 
     In positions which face the guide piece  28  and the protrusion  29  of the lever member  27  of each cam  24  in the peripheral wall  16   c  of the carriage  16 , a long slot  35  and a plurality of fitting holes  36  are formed so as to penetrate the peripheral wall  16   c . Each long slot  35  is an arc shape extended to follow a track of each guide piece  28  when each lever member  27  is rotated about the shaft  26  of each cam  24 . Moreover, the guide piece  28  of each lever member  27  is slidably engaged to each long slot  35 . 
     In addition, each fitting hole  36  is disposed in an arc shape in a regular interval (pitch) so as to follow a track of each protrusion  29  when each lever member  27  is rotated about the shaft  26  of each cam  24 . In addition, the protrusion  29  of each lever member  27  is detachably fitted to each fitting hole  36 . Therefore, since the lever member  27  is rotated and the protrusion  29  of the lever member  27  is selectively fitted to any one of the fitting holes  36 , the rotation angle of the cam  24  about the shaft  26  is changed in stages. 
     As shown in  FIGS. 3 ,  4  and  9 , in the inside of each cam  24  in the bottom in the carriage  16 , that is, in an opening  24   a  of each cam  24 , each columnar boss portion  37  serving as a fixing portion is erected. Screw hole  37   a  is formed on an upper surface of each boss portion  37 . The outer peripheral surface of each boss portion  37  comes close to the inner peripheral surface of each cam in the direction in which the shaft  26  of each cam  24  is extended. In addition, the upper end surface of each boss portion  37  is set to be lower than the highest position in the cam surface  25  of each cam  24 . 
     Moreover, in the embodiment, the inner area of the cam  24  in the carriage  16 , that is, the area in the opening  24   a  constitutes a cam forming area. In addition, each cam  24 , each boss portion  37 , and the bearing portions  32  and  34  constitute a position adjustment mechanism. 
     As shown in  FIGS. 2 and 9 , a fixed portion  39 , which is fixed to each boss portion  37  of the carriage  16  by screw  38 , is installed in the sub-carriage  20   a  so as to correspond to each cam  24 . In each fixed portion  39 , an insertion hole  39   a  into which the screw  38  is inserted into is installed so as to correspond to each boss portion  37 . 
     In addition, in a state where the screw  38  is inserted into the insertion hole  39   a  of each fixed portion  39  of the sub-carriage  20   a , each screw  38  is screwed into and tightened to the screw hole  37   a  of each boss portion  37  of the carriage  16 . Therefore, the sub-carriage  20   a  is fixed to the carriage  16 . In this case, the axis direction (the up-down direction) of each screw  38  is perpendicular to the direction (the left-right direction and the front-back direction) in which each shaft  26  of each cam  24  is extended. 
     Next, when the recording head unit  20  is fixed to the carriage  16 , the operation will be described. 
     When the recording head unit  20  is fixed to the carriage  16 , first, the recording head unit  20  is placed (accommodated) in the carriage  16 . Thereby, the lower surface of each fixed portion  39  of the sub-carriage  20   a  abuts on the cam surface  25  of each cam  24 . In this time, the inserting hole  39   a  of each fixed portion  39  is opposite (corresponding) to the screw hole  37   a  of each boss portion  37  in the up-down direction. 
     Here, in general, each part constituting the carriage  16  or the recording head unit  20  has variations in the size. Therefore, in the state where the recording head unit  20  is placed in the carriage  16 , the height or the angle of the recording head unit  20  varies. Thus, in the above-described state, if the recording head unit  20  is fixed into the carriage  16 , the distance between the nozzle forming area R of the recording head  20   b  and the printing surface of the recording sheet P varies, or the nozzle forming area R of the recording head  20   b  and the printing surface of the recording sheet P are not parallel to each other. Therefore, the printing accuracy of the printing sheet P is decreased. Thus, after the recording head unit  20  is placed in the carriage  16 , it is necessary to adjust the height or the angle of the recording head unit  20 . 
     Therefore, in the embodiment, the lever member  27  of each cam  24  is rotated and each cam  24  is rotated about the shaft  26 . Thus, the abutment position of the recording head unit  20  in the cam surface  25  of each cam  24  is adjusted. That is, in this case, the abutment position of the recording head unit  20  in the cam surface  25  of each cam  24  in which the recording head unit  20  is supported at three points is adjusted so that the distance between the nozzle forming area R of the recording head  20   b  and the printing surface of the recording sheet P is a preset value and the nozzle forming area R and the printing surface of the recording sheet P are parallel to each other. 
     Thereby, the position (the height and the angle) of the recording head unit  20  becomes the adjusted state in the carriage  16 . While maintaining the above state, in a state where each screw  38  is inserted into the insertion hole  39   a  of each fixed portion  39 , each screw  38  is screwed into and tightened to the screw hole  37   a  of each boss portion  37 . Therefore, the recording head unit  20  is fixed into the carriage  16  in the state where the position of the recording head unit  20  is adjusted in the carriage  16 . 
     In this time, the upper portions of the side walls of both sides in the axis direction of each cam  24  tend to fall inward due to the tightening force of each screw  38 , and the lower portion of each side wall tends to fall outward. However, the side walls of both sides in the axis direction of each cam  24  are supported from the inside by each boss portion  37 . Moreover, the side walls are supported from the outside by the peripheral wall  16   c  (each bearing portion  32 ) of the carriage  16  and each bearing plate  33  (each bearing portion  34 ). Therefore, a collapse of the position adjustment state of the recording head unit  20  in the carriage  16  due to the tightening force of each screw  38  is suppressed. 
     According to above-described embodiment, the following effects can be obtained. 
     (1) In the state where the position (the height and the angle) of the recording head unit  20  is adjusted by each annular cam  24  in the carriage  16 , the recording head unit  20  is tightened and fixed to each boss portion  37  which is in the inside of each cam  24  by each screw  38 . That is, in the recording head unit  20 , the abutment position of the cam surface  25  of each cam  24  and the tightening position which is tightened by each screw  38  come very close to each other. Therefore, the difference between the position aspect of the recording head unit  20  when the position is adjusted in the carriage  16  and the position aspect of the recording head unit  20  when the recording head unit  20  is tightened and fixed by each screw  38  in the carriage  16  can be small. Therefore, the collapse of the position adjustment state of the recording head unit  20  in the carriage  16  due to the tightening force of each screw  38  is suppressed. Therefore, it is possible to accurately hold the carriage  16  and the recording head unit  20  in the state where the position of the recording head unit  20  with respect to the carriage  16  is adjusted. 
     (2) Three cams  24 , which support the recording head unit  20 , are each disposed so as to draw a triangle (line up in the non-linear shape) in planar view when linearly connecting the cams  24  to one another. Therefore, due to the fact that each cam  24  is rotated, the position (the height and the angle) of the recording head unit  20  with respect to the carriage  16  can be accurately and freely adjusted. 
     (3) Each boss portion  37  is disposed so that the outer peripheral surface of each boss portion  37  comes close to the side walls of both sides in the axis direction of each cam  24  in the inside of each cam  24 . Therefore, due to the fact that the recording head unit  20  is tightened to each boss portion  37  in the carriage  16  by each screw  38 , even though the side walls of both sides in the axis direction of each cam  24  tend to fall inward, each side walls can be supported from the inside by each boss portion  37 . 
     (4) In the peripheral wall  16   c  of the carriage  16  in which each bearing portion  32  is installed and each bearing plate  33  in which each bearing portion  34  is installed, the surface of each cam  24  side of the peripheral wall  16   c  and each bearing plate  33  come close to the surface (the outer peripheral surface) in which each shaft  26  is installed in each cam  24 . Therefore, since the recording head unit  20  is fastened to each boss portion  37  in the carriage  16  by each screw  38 , even though the side walls of both sides in the axis direction of each cam  24  tend to fall outward, each side walls can be supported from the outside by the peripheral wall  16   c  (each bearing portion  32 ) of the carriage  16  and each bearing plate  33  (each bearing  34 ). 
     (5) Two cams  24  of the cams  24 , which are disposed in the rear end side in the carriage  16 , are disposed so that each shaft  26  of two cams  24  is horizontally extended along the left-right direction. In addition, one cam  24  of the cams  24 , which is disposed in the front end side in the carriage  16 , is disposed so that each shaft  26  of the one cam  24  is horizontally extended along the front-back direction. Therefore, in both side surfaces and front surface of the left-right direction (the primary scanning direction) in the carriage which is not opposite to the main guide shaft  14 , the lever member  27  for rotating the shaft  26  of each cam  24  can be installed. Each cam  24  can be easily rotated by operating each lever member  27 . 
     (6) Since each cam  24  is disposed on the outside of the nozzle forming area R in the direction (the up-down direction) which is perpendicular to the nozzle forming area R, the position of the recording head unit  20  can be accurately adjusted so that the nozzle forming area R is parallel to the recording surface of the recording sheet P by each cam  24 . 
     (7) Each fitting hole  36  is disposed in an arc shape in a regular interval (pitch) so as to follow the track of each protrusion  29  when each lever member  27  is rotated about the shaft  26  of each cam  24 . Therefore, since the lever member  27  is rotated and the protrusion  29  of the lever member  27  is selectively fitted to any one of the fitting holes  36 , the rotation angle of the cam  24  about the shaft  26  can be changed in stages. 
     Modified Embodiment 
     In addition, the above-described embodiment may be modified to other embodiments as described below. 
     At least one of the rotary cams  24  may be modified to a slide type cam. 
     Any one of two side walls other than the side walls of both sides in the axis direction of each cam  24  may be omitted. 
     Each cam  24  is not necessarily disposed on the outside of the nozzle forming area R in the direction (the up-down direction) which is perpendicular to the nozzle forming area R. 
     The axis direction of each cam  24  may be the same as each other. 
     In the peripheral wall  16   c  of the carriage  16  in which each bearing portion  32  is installed and each bearing plate  33  in which the bearing portion  34  is installed, the surface of each cam  24  side of the peripheral wall  16   c  and each bearing plate  33  does not necessarily come close to the surface (the outer peripheral surface) in which each shaft  26  is installed in each cam  24 . 
     Each boss portion  37  is not necessarily disposed so that the outer peripheral surface of each boss portion  37  comes close to the side walls of both sides in the axis direction of each cam  24  in the inside of each cam  24 . 
     The three cams  24 , which support the recording head unit  20 , may be linearly lined up in planar view. In this case, the angle adjustment of the recording head unit  20  is limited. 
     As the recording medium, a plastic film, cloth, a thin metal sheet, or the like may be used instead of the recording sheet P. 
     The recording sheet P may be a sheet paper (single paper sheet) or a continuous form paper. 
     The ink jet type printer  11  may be a so-called line head printer in which a recording head is fixed so as to not be moved and ink is ejected to a recording sheet which is transported to under the recording head. 
     In the embodiments and modified embodiments, the recording apparatus is exemplified by the ink jet type printer  11 . However, the recording apparatus may adopt a liquid ejecting apparatus in which liquid other than ink is ejected or discharged. That is, the recording apparatus may be used in various liquid ejecting apparatuses including a liquid ejection head, and the like, which eject minutely small amount of liquid droplets. Further, the liquid droplet designates a liquid state ejected from the liquid ejecting apparatus, and therefore, may include granular, tear-shaped, threadlike trailed droplets. Also, the liquid described herein may be any material in which the liquid ejecting apparatus can eject. For example, the liquid is preferable if the material is a liquid phase, and the liquid may include not only a liquid-state material having a high or low viscosity, sol, gel water, other inorganic solvent, an organic solvent, a solution, a liquid-state resin, a liquid in flowable condition such as liquid-state metal (molten metal), or a liquid as one state of a substance, but also materials in which particles of a functional material including a solid material such as a pigment or a metal particle are dissolved, dispersed to, or mixed with a solvent, and the like. Further, as described in the embodiments and the modified embodiment, the ink or liquid crystals, and the like may be exemplified as representative example of the liquid. Here, the ink includes a general water-based ink and an oil-based ink, various liquid compositions such as a gel ink, a hot melt ink or the like. As the detailed examples of the liquid ejecting apparatus, for example, there may be as follows: a liquid ejecting apparatus for ejecting a liquid including a material such as a distributed or a dissolved electrode material or color material which is used for manufacturing a liquid crystal display, EL (electro-luminescence) display, a surface luminescence display, and a color filter; a liquid ejecting apparatus for ejecting a bioorganic material used in the manufacture of a bio chip; a liquid ejecting apparatus for ejecting a liquid including a sample used as a precision pipette; a printing apparatus; a micro-dispenser; or the like. Moreover, the liquid ejecting apparatus may include; a liquid ejecting apparatus for ejecting of lubricant from a pinpoint to a precision machine such as a watch or a camera; a liquid ejecting apparatus for ejecting a transparent resin liquid such as UV curing resin onto a substrate in order to form a minute hemispherical lens (an optical lens) or the like used in an optical communication element or the like; and a liquid ejecting apparatus for ejecting an etching liquid such as an acid liquid or an alkali liquid in order to etch a substrate or the like. In addition, the aspects of the invention may be applied to any one of the above-described liquid ejecting apparatuses.