JP5518170B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an inkjet printer that performs printing on a long sheet-like print medium.

  2. Description of the Related Art Conventionally, as an ink jet printer that performs printing on a long sheet-like print medium, a print medium before printing is fed out by a feeding mechanism disposed on the rear side of the printer main body, and the ink jet head for the print medium in the printer main body Inkjet printers configured to perform printing by ejecting ink while relatively moving the ink, and to wind up a print medium on which printing has been completed by a winding mechanism disposed on the front side of the printer body are known (for example, (See Patent Document 1). In such an ink jet printer, a tension applying mechanism for applying a predetermined tension (tension) to the printing medium is provided on the feeding mechanism side or the winding mechanism side in order to appropriately feed or wind the printing medium without wrinkles or slack. There are some (see, for example, Patent Document 2 and Patent Document 3).

  FIG. 8A shows a schematic configuration of a conventional tension applying mechanism 200. The tension applying mechanism 200 includes a media arm 203 that can swing up and down around a rotation shaft 204 that is orthogonal to the feeding direction of the print medium M, and a tension bar 201 that is supported by the tip of the media arm 203 and extends in the orthogonal direction. The media arm 203 swings downward according to its own weight and slackness of the print medium M, and is configured to apply tension to the print medium M by bending the print medium by bringing the tension bar 201 into contact with the print medium. Is done. Further, the tension applying mechanism 200 includes a ballast arm 301 that can swing up and down around the rotation shaft 204 and extends toward the opposite tension applying mechanism, and a ballast member 302 attached to the tip of the ballast arm 301. The tension adjusting mechanism 300 is provided, and the tension applied to the print medium M by the tension applying mechanism 200 can be adjusted by using the torque acting on the ballast arm 301 by the ballast member 302.

JP 2007-302468 A JP 2008-279621 A Japanese Patent Laid-Open No. 2003-252501

  By the way, as shown in FIG. 8A, when the tension applying mechanism 200 and the tension adjusting mechanism 300 described above are disposed on both sides of the feeding side and the winding side, the tension adjusting mechanisms 300 do not interfere with each other. It is necessary to dispose the feeding side tensioning mechanism and the winding side tensioning mechanism at a large distance in the front-rear direction (with a distance E). For this reason, the feeding side and winding side tensioning mechanism protrude in the front-rear direction. There was a problem that the ink jet printer was enlarged. Therefore, as shown in FIG. 8B, it has been considered that the tension adjusting mechanism 300 is configured such that the ballast arm 301 extends obliquely upward. In this case, the tension between the tension applying mechanisms 300 is considered. Although the distance can be somewhat narrower than the above case (distance F <distance E), further space saving (compacting) of the tension applying mechanism 200 and the tension adjusting mechanism 300 is desired.

  In addition, since such an inkjet printer performs printing on various types of print media, the tension applying mechanism 200 is required to apply a suitable tension for each print medium. Therefore, a tension adjusting mechanism 300 is provided, and the tension applied to the print medium by the tension applying mechanism 200 can be adjusted by changing the weight of the ballast member 302. However, in order to cope with various print media, A configuration capable of adjusting the tension in a wider range is desired.

  The present invention has been made in view of such problems, and in the case where tension applying mechanisms are provided on both sides of the feeding side and the winding side, the tension applied by the tension applying mechanism is adjusted in a wider range. An object is to provide a possible inkjet printer.

  In order to achieve the above object, an ink jet printer according to the present invention includes a printer main body that performs printing on a print medium, media feeding means that feeds a long sheet-like print medium toward the printer main body, and the media feeding. Medium take-up means for taking up the print medium that has been drawn out by the means and printed in the printer main body, and applying tension to the print medium while being taken out by the medium take-out means and taken up by the medium take-up means Tension applying means. In addition, the tension applying means has a tension arm (for example, the media arms 93 and 123 in the embodiment) that can swing up and down around a rotation axis that is orthogonal to the feeding direction of the print medium, and is lowered by its own weight. A tension applying mechanism in which a tip of the tension arm swinging in contact with the print medium is applied to apply tension to the print medium, a ballast arm swingable up and down around a rotation axis orthogonal to the feed direction, and the A tension adjusting mechanism having a ballast member attached to a ballast arm, the tension adjusting mechanism capable of adjusting a tension applied to the print medium by the tension applying mechanism using a torque acting on the ballast arm by the ballast member; and the tension arm When the tension arm swings in one direction from a predetermined swing angle. A state in which the tension can be adjusted by the tension adjusting mechanism by engaging with an arm, and the tension arm is separated from the ballast arm when the tension arm swings from the predetermined swing angle to the other. A switching mechanism (for example, the fixing rings 97 and 127 and the arm side protrusions 98a and 128a of the ballast arms 98 and 128 in the embodiment) that can be switched to a state in which the torque is not applied by the adjustment mechanism is configured.

In the ink jet printer according to the present invention, the tension applying means acts on the ballast arm by the tension applying mechanism that applies the tension to the print medium by the tip of the tension arm swinging downward by its own weight and the ballast member. A tension adjusting mechanism that can adjust the tension applied to the print medium by the tension applying mechanism using the torque to be applied, and the tension arm is engaged with the ballast arm when the tension arm swings to one side from a predetermined swing angle. A switch that can be switched between a state in which tension can be adjusted by the tension adjustment mechanism and a state in which the tension arm is separated from the ballast arm and no torque is applied by the tension adjustment mechanism when the tension arm swings from the predetermined swing angle to the other. It is configured with a mechanism, the switching mechanism Therefore, engagement and disengagement of a tension arm and ballast arms, each characterized by being performed in a predetermined angle range in the oscillation angle of the tension arm. According to such a configuration, the tension can be adjusted using torque acting on the ballast arm by the ballast member as in the prior art, and the tension arm is separated from the ballast arm and tension is applied by the weight of the tension arm. Therefore, the tension can be adjusted in a wider range than the conventional tension applying means.

1 is a side view of an ink jet printer according to the present invention. It is the perspective view which looked at the ink-jet printer from the front. It is a front view which shows the principal part structure of the printer main body which comprises the said inkjet printer. It is a top view which shows the structure of a delivery side and winding side tension | tensile_strength provision means. (a), (b) is a side view which shows the action | operation of the delivery side tension | tensile_strength provision means above an engagement start angle. (a), (b) is a side view which shows the action | operation of the delivery side tension | tensile_strength provision means below from an engagement start angle. It is a schematic diagram which shows the rocking | fluctuation range of the media arm engaged with a feeding side and winding side tension adjustment mechanism. (a), (b) is a side view which shows the structure of the conventional tension | tensile_strength provision means.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, an inkjet printer P according to the present invention includes a printer main body 1 that performs printing on a print medium M, and a support portion 2 that supports the printer main body 1 at a height position at which work is easy. And a feeding device 3 for feeding the unprinted print medium M to the printer main body 1 and a winding device 4 for winding the printed print medium M. In the following description, for convenience of explanation, directions indicated by front and rear, left and right, and up and down arrows added to the drawings will be referred to as front and rear directions, left and right directions, and up and down directions, respectively.

  First, the printer main body 1 will be briefly described with reference to FIG. 3 showing the main configuration of the printer main body 1. The printer main body 1 includes a body 10 serving as a mounting base for each unit, a platen 20 that supports the print medium M, a media moving mechanism 30 that moves the print medium M supported by the platen 20 back and forth, and an upper part of the platen 20. A carriage 40 that is movably supported left and right, a carriage moving mechanism 50 that moves the carriage 40 to the left and right relative to the print medium M supported by the platen 20, and a plurality of fixedly supported carriages 40. The ink jet head 60 and a print controller 70 that controls driving of the moving mechanisms 30 and 50, ink ejection from the ink jet head 60, and the like are mainly configured.

  The body 10 includes a main body frame 11 including a lower frame 11L provided with a platen 20 supported by left and right support legs 2a constituting the support portion 2, and an upper frame 11U provided with a support structure for the carriage 40. Between the 11U and the lower frame 11L, a horizontally long window-shaped medium insertion portion 15 into which the print medium M can be inserted in the front-rear direction is formed. The body 10 is surrounded by a front cover 13a that covers the central portion of the main body frame 11 and side covers 13b and 13b that cover the left and right sides, and is configured as a horizontally-long rectangular box as a whole.

  The platen 20 is provided at the center of the left and right sides of the body 10 and is provided over the front and rear of the medium insertion portion 15. A main platen 22 having a support surface to be supported, a rear platen 21 extending rearward from the main platen 22 and provided on the rear side of the body 10, and extending forward from the main platen 22 and provided on the front side of the body 10. The front platen 23 is formed. The rear end side of the rear platen 21 and the front end side of the front platen 23 extend downward in a smooth curve, and the printing medium M fed from the feeding device 3 and introduced into the platen 20 is transferred to the rear platen 21, the main platen 22, Each upper surface is smoothly moved in the order of the front platen 23, and then discharged from the front platen 23 and taken up by the winding device 4.

  The support surface of the main platen 22 is formed with a large number of suction holes having a diameter of about several millimeters, and a decompression chamber 25 is provided on the lower side thereof so that the negative pressure can be set. By setting the negative pressure, the print medium M is sucked and held in the print unit so that the position of the print medium M does not shift during printing.

  The media moving mechanism 30 is provided so as to be rotatable about a rotation shaft extending in the left and right directions, and rotationally drives a cylindrical feed roller 31 and a feed roller 31 that are disposed with the upper peripheral surface exposed to the support surface of the main platen 22. And a timing belt 32 wound between a driven pulley coupled to the shaft end of the feed roller 31 and a drive pulley coupled to the shaft end of the roller drive motor 33, respectively. The roller assembly 35 includes a plurality of roller assemblies 35 that have a rotatable pinch roller 36 and are disposed above the feed roller 31 at predetermined intervals on the left and right.

  The roller assembly 35 is configured to be displaceable between a clamp position where the pinch roller 36 is elastically engaged with the feed roller 31 and an unclamp position where the pinch roller 36 is spaced above the feed roller 31. By rotating the feed roller 31 in a state where the assembly 35 is set at the clamp position and the print medium M is sandwiched between the upper and lower rollers 36 and 31, the feed amount of the print medium M corresponding to the rotation angle of the feed roller 31, that is, The sheet is conveyed back and forth by a feed amount corresponding to the drive control signal output from the print controller 70 to the roller drive motor 33.

  The carriage 40 is supported by a guide rail 45 that extends to the left and right in parallel with the feed roller 31 and is attached to the upper frame 11U so as to be movable to the left and right. The guide rail 45 is a support rail of a linear motion bearing. The carriage 40 is fixed to a slide block fitted to the guide rail 45 and is supported so as to be slidable left and right, and is moved left and right by the carriage moving mechanism 50. .

  The carriage moving mechanism 50 includes a driving pulley 51 and a driven pulley 52 provided near the left and right side ends of the guide rail 45, a carriage driving motor 53 that rotationally drives the driving pulley 51, and the driving pulley 51 and the driven pulley 52. The timing belt 55 is wound around and the carriage 40 is connected and fixed to the timing belt 55. The rotation of the carriage drive motor 53 is controlled by the print controller 70, and the carriage 40 is slid left and right (reciprocated) by a feed amount corresponding to a drive control signal output from the print controller 70 to the carriage drive motor 53.

  The inkjet head 60 has a number of nozzles for ejecting ink droplets formed on the lower surface, and is fixedly supported by the carriage 40 so that the lower surface (nozzle surface) is separated from the print medium M by a predetermined gap (interval). There are various configurations of the arrangement configuration of the inkjet head 60, and an appropriate configuration can be used. In this embodiment, the inkjet heads 60 of four colors (for example, black, cyan, magenta, and yellow) are arranged side by side. The arranged head configuration is illustrated. The carriage 40 can be moved up and down by a carriage lifting mechanism (not shown), and thereby the gap between the nozzle surface of the inkjet head 60 and the printing medium M is adjusted according to the surface state of the printing medium M and the like. It is possible.

  The print controller 70 controls the driving of the roller drive motor 33 in the medium moving mechanism 30 to position the print medium M supported on the platen 20 by intermittently feeding it forward, and further driving the carriage in the carriage moving mechanism 50. By synchronously controlling the driving of the motor 53 and the ejection of ink from the nozzles of each inkjet head 60, images such as characters and graphics corresponding to the printing program are formed on the printing medium M. At this time, according to the feed amount of the printing medium M on the platen 20 by the medium moving mechanism 30, the unprinted printing medium M is fed out by the feeding device 3 and introduced into the platen 20, and the winding device 4. As a result, the printed print medium M discharged from the platen 20 is wound up.

  Next, the feeding device 3 and the winding device 4 will be described. As shown in FIG. 1, the feeding device 3 is provided on the rear side of the support portion 2, and supports a cylindrical feeding shaft 6 (see FIG. 2) around which an unprinted print medium M is wound. At the same time, the medium feeding means 80 for feeding the printing medium M by rotating the feeding shaft 6, and the feeding-side tension applying means 90 for applying tension to the printing medium M while being fed by the medium feeding means 80 and introduced into the platen 20, The feeding controller 100 controls the feeding amount of the print medium M by the media feeding means 80.

  The media feeding means 80 is disposed in the rear intermediate portion of the left and right support legs 2a, and is rotatable on the support shaft 81, which is inserted into the feeding shaft 6 and is rotatable integrally with the feeding shaft 6. The shaft support portions 82 and 82 are detachably supported, and the shaft drive mechanism 85 is provided in the left shaft support portion 82 and rotationally drives the support shaft 81. The shaft drive mechanism 85 includes, for example, a drive motor, an output shaft of the drive motor, a timing belt wound around the end of the support shaft 81, and the like, and corresponds to a drive control signal input from the feeding controller 100. Then, the support shaft 81 is rotationally driven. The printing medium M in an unprinted state supported between the left and right shaft support portions 82 and 82 by the support shaft 81 has a platen 20 (rear platen) with a feed amount (feed speed) corresponding to the rotation amount (rotation speed) of the support shaft 81. It goes out toward 21).

  As shown in FIGS. 1 and 4, the feeding-side tension applying means 90 is disposed on a cylindrical bar-shaped tension bar 91 that is in contact with the printing medium M horizontally and on the bottom 2b of the left and right support legs 2a. The rotating shaft support portions 92 and 92, the feeding-side rotating shaft 94 that is supported by the left and right rotating shaft support portions 92 and 92 and is rotatably supported, and the base end portion are fixed to the end portion of the feeding-side rotating shaft 94. And a feeding-side tension applying mechanism 95 composed of a pair of left and right media arms 93 and 93 that rotatably supports the end of the tension bar 91 at the distal end, and the base end rotates with respect to the feeding-side rotating shaft 94. A feeding-side tension adjusting mechanism 96 including a feeding-side ballast arm 98 that is freely supported and has a feeding-side ballast member 99 detachably attached to the tip portion, and a feeding-side rotation Is fixed to the shaft 94 consists of a fixed ring 97. which rotates integrally with the feed-side rotating shaft 94.

  As described above, the media arms 93 and 93 are fixed to the left and right ends of the feeding-side rotation shaft 94 as described above, and swing up and down with the rotation of the feeding-side rotation shaft 94 around the base end. The tension bar 91 swinging downward by its own weight and supported at the tip portion is configured to contact the print medium M while being fed from the feed shaft 6 and reaching the platen 20. A swing angle detector (not shown) for detecting the swing angle of the media arm 93, that is, the height position of the tension bar 91, is disposed in the vicinity of the base end portion of the media arm 93. The detection signal detected by the swing angle detector is output to the feeding controller 100.

  The fixing ring 97 is configured to rotate integrally with the feeding-side rotating shaft 94 extending in the left-right direction, that is, according to the swing of the media arm 93 fixed to the feeding-side rotating shaft 94. A ring-side protruding portion 97a protruding in the orthogonal direction is formed. The ring-side protruding portion 97a rotates clockwise in a left side view in response to the downward swing of the media arm 93, and the media arm 93 has a predetermined swing angle (hereinafter referred to as an engagement start angle). When it becomes, it contacts for the first time with the lower surface of the arm side protrusion part 98a of the feeding side ballast arm 98 mentioned later (refer FIG. 5). The state in which the ring-side protruding portion 97a is in contact with the arm-side protruding portion 98a in this manner is referred to as an engaged state of the fixing ring 97 and the feeding-side ballast arm 98 and will be described below.

  The delivery-side ballast arm 98 is supported by a delivery-side rotation shaft 94 adjacent to the fixing ring 97 at the base end, and extends from the base end so as to straddle a winding-side rotation shaft 124 described below from below. Is formed. The feeding-side ballast arm 98 is provided so as to be shifted in the left-right direction (direction perpendicular to the feeding direction of the printing medium M) with respect to a take-up ballast arm 128 described later (see FIG. 4), and is partially in side view. Are arranged in an overlapping manner (see FIG. 1). The feeding-side ballast member 99 attached to the leading end of the feeding-side ballast arm 98 has a tension bar 91 and a feeding-side rotating shaft 94 in a side view when the fixing ring 97 and the feeding-side ballast arm 98 are engaged. It is located on the extended line of the straight line connecting. The feeding-side ballast member 99 is composed of a plurality of weight members that can be attached to and detached from the tip of the feeding-side ballast arm 98, and the weight of the feeding-side ballast member 99 can be changed by changing the number of weight members. It has become.

  In the vicinity of the proximal end portion of the feeding-side ballast arm 98, an arm-side protruding portion 98a that protrudes toward the fixing ring 97 is formed, and when the media arm 93 reaches the engagement start angle as described above, The ring-side protruding portion 97a of the fixing ring 97 comes into contact with the side protruding portion 98a, and the fixing ring 97 and the feeding-side ballast arm 98 are engaged. In this way, when the media arm 93 swings below the engagement start angle, the feeding-side ballast arm 98 is centered on the base end portion (feeding-side rotating shaft 94) of the media arm 93. It swings up and down according to the swing (in conjunction with the media arm 93) (see FIG. 6A). On the other hand, when in the disengaged state, that is, when the media arm 93 swings above the engagement start angle, the feeding-side ballast arm 98 comes into contact with the bottom 2b of the support leg 2a and becomes stationary (FIG. 5).

  When the media arm 93 swings below the engagement start angle and reaches a predetermined swing angle (hereinafter referred to as a lower limit swing angle), the tip of the media arm 93 is provided on the bottom 2b. Abutting on the stopper member 2c, the further downward swing of the media arm 93 is restricted (see FIG. 6B). At this time, the feeding-side ballast arm 98 and the winding-side rotating shaft 124 are not in contact with each other.

  In the feeding-side tension applying means 90 configured as described above, the length of the printing medium M during which the media arm 93 reaches the platen 20 from the feeding shaft 6 due to the weight of the tension bar 91 and the left and right media arms 93 (hereinafter, referred to as the length of the printing medium M). (Referred to as slack on the feeding side of the print medium M), and the print medium M is bent by bringing the tension bar 91 into contact with the inside of the print medium M, thereby bending the print medium M with respect to the print medium M. A tension according to the height position of the tension bar 91, that is, the swing angle of the media arm 93 is applied in the direction opposite to the transport direction.

  At this time, when the media arm 93 swings below the engagement swing angle (swing range B shown in FIG. 7), the fixing ring 97 and the delivery-side ballast arm 98 are engaged and the delivery-side The ballast arm 98 is interlocked with the media arm 93, and the tension applied to the print medium M can be adjusted by using the torque acting on the feeding-side ballast arm 98 by the feeding-side ballast member 99 (the tension is higher than the above case). Reduced). At this time, by changing the weight of the feeding-side ballast member 99 according to the characteristics (hardness and the like) of the print medium M, it is possible to apply a tension suitable for the print medium M to be printed. Further, since the feeding-side ballast member 99 is arranged on a straight line in a side view with the tension bar 91 and the feeding-side rotating shaft 94 via the feeding-side ballast arm 98, the weight of the feeding-side ballast member 99 is set to the printing medium. It is possible to efficiently act on the tension applied to M.

  On the other hand, when the media arm 93 swings above the engagement start angle (swing range A shown in FIG. 7), the fixing ring 97 and the feeding-side ballast arm 98 do not engage with each other. Is separated from the supply-side ballast arm 98, and the tension due to the weight of the tension bar 91 and the media arm 93 is applied to the print medium M.

  As shown in FIGS. 1 and 4, the feeding controller 100 is disposed in the left rotation shaft support portion 92, and controls the driving of the shaft driving mechanism 85 of the media feeding means 80 to thereby support the support shaft 81. The supported printing medium M is fed out by a predetermined feeding amount based on the feeding amount of the printing medium M on the platen 20 by the medium moving mechanism 30 (see FIG. 3). Further, the feeding controller 100 controls the feeding amount so that the swing angle of the media arm 93 is maintained within a predetermined swing range. The predetermined swing range can be arbitrarily set. For example, when the swing range is set within the above-described swing range B, the tension applied to the print medium M by the feeding-side tension adjusting mechanism 96 can be always adjusted. Become.

  As shown in FIG. 1, the winding device 4 is provided on the front side of the support portion 2 and supports a cylindrical winding shaft 8 (see FIG. 2) for winding the printed print medium M. In addition, the take-up shaft 8 is rotated to take up the print medium M, and the take-up means for applying tension to the print medium M while being discharged from the platen 20 and taken up by the medium take-up means 110. The side tension applying unit 120 and a winding controller 130 for controlling the winding amount of the print medium M by the media winding unit 110 are configured. The winding device 4 is basically configured in the same manner as the above-described feeding device 3.

  The media take-up means 110 is disposed in a bar-like support shaft 111 that is inserted through the take-up shaft 8 and can rotate integrally with the take-up shaft 8, and is disposed at the front intermediate portion of the left and right support legs 2 a. It comprises shaft support portions 112 and 112 that are rotatably and detachably supported, and a shaft drive mechanism 115 that is provided in the left shaft support portion 112 and rotationally drives the support shaft 111. The shaft drive mechanism 115 includes, for example, a drive motor, a timing belt wound around the output shaft of the drive motor and the end of the support shaft 111, and the like, and receives a drive control signal input from the winding controller 130. Accordingly, the support shaft 111 is rotationally driven. The printed print medium M discharged from the platen 20 (front platen 23) is rotated around the winding shaft 8 supported between the left and right shaft support portions 112, 112 by the support shaft 111. Winding is performed at a winding amount (winding speed) corresponding to (rotational speed).

  As shown in FIGS. 1 and 4, the winding-side tension applying means 120 is disposed on a cylindrical bar-like tension bar 121 that is in contact with the printing medium M horizontally and on the bottom 2b of the left and right support legs 2a. The rotating shaft support portions 122 and 122 provided, the winding side rotating shaft 124 that is supported by the left and right rotating shaft support portions 122 and 122 and is rotatably supported, and the base end portion is the end of the winding side rotating shaft 124. And a winding-side tension applying mechanism 125 including a pair of left and right media arms 123 and 123 that rotatably supports the end of the tension bar 121 at the tip, and a base end of the winding-side rotating shaft. Winding-side tension composed of a winding-side ballast arm 128 that is rotatably supported with respect to 124 and has a winding-side ballast member 129 detachably attached to the tip. And down adjustment mechanism 126, and a fixing ring 127 Metropolitan rotating fixed to the take-up rotary shaft 124 integrally with the take-up rotary shaft 124.

  As described above, the media arms 123 and 123 have their base ends fixed to the left and right ends of the take-up rotary shaft 124, respectively, and move up and down with the rotation of the take-up rotary shaft 124 around the base end. The tension bar 121 swingable downward by its own weight and supported at the tip end portion is configured to come into contact with the printing medium M while being discharged from the platen 20 and wound on the winding shaft 8. ing. In the vicinity of the base end portion of the media arm 123, a swing angle detector (not shown) for detecting the swing angle of the media arm 123, that is, the height position of the tension bar 121 is disposed. The detection signal detected by the swing angle detector is output to the winding controller 130.

  The fixing ring 127 rotates integrally with the winding-side rotary shaft 124 extending in the left and right directions, that is, according to the swing of the media arm 123 fixed to the winding-side rotary shaft 124. A ring side protrusion (not shown) protruding in a direction orthogonal to the shaft 124 is formed. The ring-side protruding portion rotates counterclockwise in the left side view in response to the downward swing of the media arm 123, and the media arm 123 has a predetermined swing angle (hereinafter referred to as an engagement start angle). When it becomes, it contacts for the first time with the lower surface of the arm side protrusion part 128a of the winding side ballast arm 128 mentioned later. The state in which the ring-side protruding portion is in contact with the arm-side protruding portion 128a in this manner is referred to as an engagement state between the fixing ring 127 and the winding-side ballast arm 128 and will be described below.

  The winding-side ballast arm 128 has a base end portion that is pivotally supported by the winding-side rotating shaft 124 adjacent to the fixing ring 127 and extends rearward from the base end portion so as to straddle the feeding-side rotating shaft 94 from below. Is formed. The take-up ballast arm 128 is provided so as to be shifted in the left-right direction (the direction perpendicular to the feeding direction of the print medium M) with respect to the supply-side ballast arm 98 (see FIG. 4), and a part of the take-up ballast arm 128 is seen in side view. They are arranged in an overlapping manner (see FIG. 1). The winding-side ballast member 129 attached to the leading end of the winding-side ballast arm 128 has the tension bar 121 and the winding side in a side view when the fixing ring 127 and the winding-side ballast arm 128 are engaged. It is located on the extended line of the straight line connecting the rotation shaft 124. The take-up ballast member 129 is composed of a plurality of weight members that can be attached to and detached from the tip of the take-up ballast arm 128, similarly to the above-described payout-side ballast member 99. By changing the number of weight members, The weight of the winding side ballast member 129 can be changed.

  In the vicinity of the base end portion of the winding side ballast arm 128, an arm side protruding portion 128a protruding toward the fixing ring 127 is formed, and when the media arm 123 reaches the engagement start angle as described above, The ring-side protruding portion of the fixing ring 127 comes into contact with the arm-side protruding portion 128a, and the fixing ring 127 and the winding-side ballast arm 128 are engaged. In this way, when the media arm 123 swings below the engagement start angle, the take-up side ballast arm 128 is centered on the base end (the take-up side rotating shaft 124). It swings up and down according to the swing of 123 (in conjunction with the media arm 123). On the other hand, when in the disengaged state, that is, when the media arm 123 swings above the engagement start angle, the take-up side ballast arm 128 comes into contact with the bottom portion 2b of the support leg 2a and becomes stationary.

  When the media arm 123 swings below the engagement start angle and reaches a predetermined swing angle (hereinafter referred to as a lower limit swing angle), the tip of the media arm 123 is provided on the bottom 2b. The contact with the stopper member 2c is restricted, and the further downward swing of the media arm 123 is restricted. At this time, the winding-side ballast arm 128 and the feeding-side rotating shaft 94 are not in contact with each other.

  In the take-up side tension applying means 120 configured as described above, the length of the print medium M until the media arm 123 is taken up from the platen 20 to the take-up shaft 8 by the weight of the tension bar 121 and the left and right media arms 123. The print medium M is bent downward by swinging downward according to the length of the print medium M (hereinafter referred to as the slack on the winding side of the print medium M), and bending the print medium M by bringing the tension bar 121 into contact with the inside of the print medium M. A tension according to the height position of the tension bar 121, that is, the swing angle of the media arm 123 is applied to M in the transport direction.

  At this time, when the media arm 123 swings below the engagement swing angle (swing range D shown in FIG. 7), the fixing ring 127 and the winding-side ballast arm 128 are engaged and wound. The take-up side ballast arm 128 is interlocked with the media arm 123, and the tension applied to the print medium M can be adjusted using the torque acting on the take-up side ballast arm 128 by the take-up side ballast member 129 (in the case described above). Than the tension is reduced). At this time, by changing the weight of the winding side ballast member 129 according to the type of the print medium M, it is possible to apply a tension suitable for the print medium M to be printed. Further, since the take-up side ballast member 129 is arranged on the straight line in a side view with the tension bar 121 and the take-up side rotating shaft 124 via the take-up side ballast arm 128, The weight can be efficiently applied to the tension applied to the print medium M.

  On the other hand, when the media arm 123 swings above the engagement start angle (swing range C shown in FIG. 7), the fixing ring 127 and the winding-side ballast arm 128 do not engage with each other. 123 is separated from the take-up ballast arm 128, and the tension due to the weight of the tension bar 121 and the media arm 123 is applied to the print medium M.

  As shown in FIGS. 1 and 4, the take-up controller 130 is disposed in the left rotation shaft support portion 122, and controls the drive of the shaft drive mechanism 115 of the media take-up means 110, thereby supporting the support shaft. The printing medium M that has been printed on the winding shaft 8 supported by 111 is wound with a predetermined winding amount based on the feed amount of the printing medium M on the platen 20 by the medium moving mechanism 30 (see FIG. 3). . The winding controller 130 controls the winding amount so that the swing angle of the media arm 123 is maintained within a predetermined swing range. The predetermined swing range can be arbitrarily set. For example, when the predetermined swing range is set within the swing range D, the tension applied to the print medium M by the winding-side tension adjusting mechanism 126 can be always adjusted. It becomes.

  In the feeding side tension applying means 90 and the winding side tension applying means 120 configured as described above, the feeding side tension adjusting mechanism 96 (feeding side ballast arm 98) and the winding side tension adjusting mechanism 126 (winding side ballast arm). 128) are provided so as to be shifted in a direction (left-right direction) orthogonal to the feeding direction of the print medium M, and are partially overlapped when viewed from the side, so that the conventional feeding side and winding shown in FIG. Compared with the side tension applying means, the feeding side tension applying means 90 and the winding side tension applying means 120 can be greatly reduced in space (compact).

  Further, the media arms 93 and 123 are separated from the ballast arms 98 and 128 according to the swing angle of the media arms 93 and 123, and the tension due to the weights of the tension bars 91 and 121 and the media arms 93 and 123 is applied to the print medium M. The tension applied to the print medium M can be adjusted using the torque applied to the ballast arms 98 and 128 by the ballast members 99 and 129 in conjunction with the media arms 93 and 123. Therefore, the tension can be adjusted in a wider range than the conventional tension applying means.

M Print medium 1 Printer body 2 Support section (support body)
3 Media feeding device 4 Media winding device 80 Media feeding means 90 Feeding side tension applying means 92, 122 Rotating shaft support (support)
93,123 Media arm (tension arm)
95 Feeding-side tension applying mechanism 96 Feeding-side tension adjusting mechanism 97, 127 Fixing ring (switching mechanism)
98 Feeding side ballast arm 98a, 128a Arm side protrusion (switching mechanism)
99 Feeding side ballast member 110 Media winding means 120 Winding side tension applying means 125 Winding side tension applying mechanism 126 Winding side tension adjusting mechanism 128 Winding side ballast arm 129 Winding side ballast member

Claims (2)

A printer main body that performs printing on a print medium, a medium feeding means that feeds a long sheet-like print medium toward the printer main body, and the print medium that is fed by the media feeding means and printed on the printer main body In an ink jet printer comprising: a medium take-up means for taking up a paper; and a tension applying means for applying a tension to the print medium while being taken out by the medium take-up means and being taken up by the media take-up means. ,
The tension applying means is
It has a tension arm that can swing up and down around a rotation axis orthogonal to the feeding direction of the print medium, and the tip of the tension arm that swings downward by its own weight comes into contact with the print medium and tensions the print medium. A tension applying mechanism for applying
The tension applying mechanism includes a ballast arm that can swing up and down around a rotation axis that is orthogonal to the feed direction, and a ballast member that is attached to the ballast arm, and the torque that acts on the ballast arm by the ballast member. A tension adjusting mechanism capable of adjusting the tension applied to the print medium by:
A state in which the tension arm is engaged with the ballast arm when the tension arm swings in one direction from a predetermined swing angle and the tension can be adjusted by the tension adjustment mechanism; A switching mechanism that can be switched to a state in which the torque is not applied by the tension adjusting mechanism by separating the tension arm from the ballast arm when swinging from the swing angle to the other ;
The ink jet printer according to claim 1, wherein the tension mechanism and the ballast arm are engaged and disengaged within a predetermined angle range of the swing angle of the tension arm by the switching mechanism . As the ballast arm, provided with a feeding side ballast arm and a winding side ballast arm,
The feeding-side ballast arm and the winding-side ballast arm are arranged so as to be shifted from each other in a direction perpendicular to the feeding direction of the printing medium.
The inkjet printer according to claim 1.

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