JP2005212425A - Medium conveyance device and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium conveyance device capable of conveying a medium without floating the medium even if the type of medium is changed, and a recording device and a liquid injection device equipped with the medium conveyance device. <P>SOLUTION: A combination of a high rib 52 and a low rib 53 is formed in the direction orthogonal to the conveyance direction of the medium conveying face 51, and a suction hole 55 is formed in a bottom face 54a between the ribs. Thereby, because the ribs can be formed at intervals coinciding with the interval of cockling occurring on a comparatively weak medium and the high ribs can be formed at intervals coinciding with that of cockling occurring on a comparatively strong medium between the high rib can be formed, the comparatively weak medium can be disposed almost in contact with the recess between the ribs. On the other hand, the comparative strong medium does not interfere with the low rib and can be made disposed almost in contact with the recess between the high and the low ribs. Accordingly, the medium can be conveyed without floating the medium even if the type of medium is changed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a medium conveying apparatus that conveys a medium while sucking the medium, a recording apparatus including the medium conveying apparatus, and a liquid ejecting apparatus.

  An ink jet printer, which is one of recording apparatuses, includes a paper transport roller that transports a paper that is a recording medium, a paper transport device that has a platen that supports the surface of the paper transported by the paper transport roller, and ink particles. A recording head for discharging, a carriage on which the recording head is mounted, and a carriage that reciprocates in the direction perpendicular to the sheet conveyance are provided. The paper feed roller is disposed on the upstream side of the sheet transport relative to the platen, and the recording head mounted on the carriage is disposed above the sheet transport surface of the platen with a predetermined gap. In such a configuration, the ink jet printer rotates the paper feed roller to convey the sheet on the sheet conveying surface of the platen, and reciprocates the carriage to eject ink particles from the nozzles of the recording head. To record.

  In such an ink jet printer, when an image on which a large number of ink particles are ejected, such as a solid image, is recorded on the paper, the paper absorbs a large amount of ink and the paper is transported in the orthogonal direction after recording. In some cases, so-called cockling occurs, which undulates and swells toward the recording head. When this cockling occurs and develops, the gap between the recording surface of the paper and the nozzle formation surface of the recording head becomes non-uniform, resulting in uneven recording due to variations in the flying distance of the ink particles, or the paper There is a problem that the recording head contacts and gets dirty.

  Therefore, a plurality of ribs having the same height are formed on the sheet transport surface of the platen at predetermined intervals in the direction perpendicular to the sheet transport, and suction holes are perforated on the top surface of the rib and the bottom surface of the recess between the ribs. Has been. Thus, the sheet conveyed on the sheet conveying surface of the platen is first sucked and recorded in the suction holes on the upper surface of the ribs, and then sucked into the suction holes on the bottom surface of the recess between the ribs. The cock ring generated in the step is absorbed by the recesses between the ribs. Therefore, the distance between the recording surface of the paper and the nozzle formation surface of the recording head can be kept substantially uniform, and recording unevenness and paper contamination can be prevented.

JP 2003-246524 A

  Among various types of paper, the pitch of cockling that occurs on plain paper or proof paper that is relatively weak is smaller than the pitch of cockling that occurs on photographic paper or cardboard that is relatively strong. For this reason, when the pitch of ribs formed on the paper transport surface of the platen of the conventional ink jet printer described above is matched with the pitch of cockling generated on plain paper or proof paper that is relatively weak, When sucking plain paper, proof paper, etc., which is weak, it can be substantially along the ribs and the recesses. However, when suctioning relatively stiff photographic paper or cardboard, etc., the rib formation pitch is smaller than the pitch of cockling generated on relatively stiff photographic paper or cardboard. There is a case where you can't be able to follow and rise up.

  The present invention has been made in view of the various problems as described above, and an object of the present invention is to provide a medium conveying apparatus and a medium conveying apparatus capable of conveying a medium without raising the medium even if the type of the medium is different. It is an object of the present invention to provide a recording apparatus and a liquid ejecting apparatus.

  In order to achieve the above object, the medium conveying apparatus of the present invention is a medium conveying apparatus that conveys a medium while sucking the medium, and is formed by combining high ribs and low ribs in a direction perpendicular to the medium conveying surface. It is characterized in that a suction hole is formed on the bottom surface between them. As a result, the formation pitch of each rib is matched to the pitch of the cock ring that is generated in a relatively weak medium, and the formation pitch of the high rib is matched to the pitch of the cock ring that is generated in a relatively strong medium. Therefore, the medium with relatively low stiffness can be substantially along the ribs and the recesses between the ribs regardless of the height of the ribs. On the other hand, the relatively stiff medium can be substantially along the high ribs and the recesses between the high ribs without interfering with the low ribs. Therefore, even if the type of medium is different, the medium can be transported without being lifted.

  The ribs are formed at an equal pitch. As a result, not only a medium having a relatively low waist but also a medium having a relatively strong waist can surely absorb cockling generated at a substantially equal pitch. The high ribs and the low ribs are alternately formed. Thereby, it is possible to cope with cockling that occurs in a medium with relatively weak waist and cockling that occurs in a medium with relatively strong waist. Further, the low rib is formed so that the side edge portion of the medium is positioned on the low rib. As a result, the side edge of the medium that is relatively easy to lift can be pulled downward, and therefore, lifting due to lifting from the side edge of the medium can be prevented.

  Moreover, the place where the said low rib is formed continuously is characterized by the fact that a pseudo high rib is formed. As a result, even when low ribs have to be continuously formed in order to support various sizes of media, the low ribs and pseudo high ribs are alternately arranged, so cockling is ensured. Can be absorbed into. Further, a suction hole is formed in the upper surface of each rib. Thereby, since the whole medium can be sucked, it is possible to reliably prevent the medium from floating.

  In order to achieve the above object, the recording apparatus of the present invention is a recording apparatus for recording on a recording medium, and is provided with each of the above-described medium transport devices. In order to achieve the above object, the liquid ejecting apparatus of the present invention is a liquid ejecting apparatus that ejects a liquid onto a medium to be ejected, and is characterized by including each of the above-described medium conveying apparatuses. Thereby, a recording apparatus or a liquid ejecting apparatus that exhibits the above-described effects can be provided.

  1 and 2 are perspective views of an external configuration example of an ink jet printer that is one of recording apparatuses according to an embodiment of the present invention as viewed from the front side, and FIG. 3 is a perspective view of the same as viewed from the back side. 4 and 4 are perspective views showing the internal structure thereof. The ink jet printer 100 is a large printer capable of recording up to a relatively large size cut paper such as JIS standard A0 size or JIS standard B0 size and roll paper R having the paper width. As shown in FIGS. 1 to 4, the ink jet printer 100 includes a rectangular parallelepiped printer body 110 and printer legs 120 that support the printer body 110.

  The printer main body 110 is divided into upper and lower layers as shown in FIGS. 1 to 4, and a roll paper storage portion 130 is disposed at the boundary between the upper and lower layers on the back side as shown in FIG. ing. As shown in FIGS. 1 to 4, a paper supply / discharge unit 140 and a recording unit 150 including characteristic portions of the present invention are disposed in the upper layer. Further, as shown in FIGS. 1 to 4, a sheet suction unit 160 is disposed at the center of the lower layer, and an ink supply unit 170 is disposed on the left side of the lower layer when viewed from the front side. A head characteristic recovery unit 180 and a drive control unit 190 are arranged vertically on the right side of the lower layer. As shown in FIGS. 1 to 4, a waste ink recovery unit 200 is disposed below the drive control unit 190 and beside the printer leg 120.

  As shown in FIGS. 1 to 3, the printer main body 110 includes an upper housing 111 made of plastic or sheet metal covering the paper supply / discharge unit 140 and the recording unit 150, a paper suction unit 160, an ink supply unit 170, and head characteristics recovery. A lower housing 112 made of plastic or sheet metal that covers the part 180 and the drive control part 190 is provided. As shown in FIG. 2, the upper housing 111 is provided with a body cover 113 made of plastic or sheet metal so as to be openable from the center front surface to the center upper surface. Further, as shown in FIG. 2, the lower housing 112 is provided with an ink cover 114 made of plastic or sheet metal so that the front surface of the ink supply unit 170 can be opened.

  As shown in FIGS. 1 and 2, the main body cover 113 is supported so that the rear portion is rotatable with respect to the upper housing 111, and the user puts his / her finger into a recessed finger-hanging portion 113 a formed on the front surface. It opens and closes by being pushed up or pushed down. The user can open the main body cover 113 to largely open the upper part of the paper supply / discharge unit 140 and the recording unit 150, so that the maintenance operation of the recording head 152, the carriage 153, etc., the paper jam during recording or transporting, etc. It is possible to easily perform the operation of canceling the paper conveyance error. Further, as shown in FIGS. 1 and 3, the main body cover 113 is provided with a window 113b made of transparent or translucent plastic on a part of its upper surface. The user can visually recognize the recording state and the conveyance state by looking inside the window 113b without opening the main body cover 113.

  As shown in FIGS. 1 and 2, the ink cover 114 is supported so that both sides thereof are slidable with respect to the lower housing 112, and the user puts his / her finger into a recessed finger-hook part 114 a formed on the front surface. It opens and closes by being pushed up or pushed down. Since the user can open the front surface of the ink supply unit 170 by opening the ink cover 114, the user can easily replace the ink cartridge 10 or the like. Further, as shown in FIGS. 1 and 2, the ink cover 114 is provided with a window 114b made of a transparent or translucent plastic at a part of the front surface. The user can view the state of the ink cartridge 10 by looking through the window 114b without opening the ink cover 114.

  Further, as shown in FIGS. 1 to 3, the printer main body 110 is provided with an operation panel 115 for the user to operate recording control and the like on the upper surface of the upper right layer when viewed from the front side. . The operation panel 115 is provided with a liquid crystal screen and various buttons so that the user can operate the buttons while checking the liquid crystal screen. Since the user can perform a reliable operation by visual recognition, an operation error, an operation error, and the like can be eliminated.

  As shown in FIGS. 1 to 4, the printer leg portion 120 includes two inverted T-shaped support columns 121 and a reinforcing column 122 spanned between the support columns 121. The printer main body 110 is placed on the support column 121 and fixed with screws. Since the printer main body 110 is lifted by the printer legs 120, the user can easily perform a paper supply / discharge process, various maintenance processes, and the like. Furthermore, it becomes possible to install a paper discharge receiving portion in the space of the printer leg portion 120, so that recorded paper can be efficiently collected and contamination of the recorded paper can be prevented.

  As shown in FIG. 3, the roll paper storage unit 130 is inserted in the inner periphery of the roll paper R to support the roll paper R, and the both ends of the spindle 131 are pivotally supported. Has no bearing. The back surface of the sheet suction unit 160 is formed so as to be recessed from the back surfaces of the ink supply unit 170 and the back surfaces of the head characteristic recovery unit 180 and the drive control unit 190 on both sides of the sheet suction unit 160. 130 is disposed.

  That is, bearings (not shown) are provided on opposite sides of the ink supply unit 170, the head characteristic recovery unit 180, and the drive control unit 190 to support the spindle 131 in the main scanning direction so as to pivotally support both ends thereof. . Then, the roll paper R can be set without protruding from the back side of the printer main body 110 by bridging the spindle 131 penetrating the inner periphery of the roll paper R between these bearings.

  As shown in FIG. 4, the paper supply / discharge unit 140 includes a paper feed roller 141 and a paper feed driven roller 142. The paper feed roller 141 and the paper feed follower roller 142 are arranged so that the shaft faces the main scanning direction and the circumferential surface is up and down on the downstream side of the paper feed from the roll paper storage unit 130, that is, the rear side in the printer main body 110. It arrange | positions so that it may oppose. The paper feed roller 141 is formed as a single long roller, and the peripheral surface portion slightly larger than the maximum recordable paper width is coated with ceramic powder or the like. As a result, slippage during paper feeding can be prevented, and the paper can be fed out with high accuracy. Both ends of the paper feed roller 141 are axially supported by side frames 116 via bearings (not shown), and are driven to rotate forward and backward by a driving force transmitted from the paper feed motor 143 through the pulley 144 and the belt 145. It has become.

  The paper feed driven roller 142 is formed as a plurality of short rollers, and is pivotally supported by a plurality of driven roller support members 146 arranged in parallel in the axial direction above the paper feed roller 141. The paper feed driven roller 142 is pressed against the paper feed roller 141 by a biasing member such as a spring (not shown) attached to the driven roller support member 146, and follows the forward / reverse rotation drive of the paper feed roller 141. It is designed to rotate forward and reverse. Thus, the sheet can be firmly pressed from both sides and sent out, so that highly accurate recording can be performed. The paper feed roller 141 and the paper feed driven roller 142 sandwich the roll paper R and the cut paper fed from the paper feed port 147 formed between the upper and lower layers of the printer main body 110 shown in FIG. 2 and 4 are sent out onto the platen 151 of the recording unit 150 and discharged from a paper discharge port 148 formed between upper and lower layers of the printer main body 110 shown in FIG.

  As shown in FIGS. 2 and 4, the recording unit 150 includes a platen 151, which is a characteristic part of the present invention, arranged on the downstream side of the conveyance immediately from the paper feed roller 141, and a carriage on which the recording head 152 is mounted. 153 and a cutter 154 attached to the carriage 153. Further, the recording unit 150 includes a flexible flat cable (hereinafter referred to as FFC) (not shown) that electrically connects the recording head 152 and a drive control unit 190 for executing recording, an ink cartridge containing the recording head 151 and ink. And an ink tube (not shown) that connects to the printer 10.

  The platen 151 is formed in a rectangular flat plate shape having a length slightly larger than the maximum recordable paper width, and is disposed along the paper feed roller 141. The platen 151 has a plurality of holes (not shown) connected to the paper suction unit 160 from the front surface to the back surface, and a plurality of uneven portions (not shown) that absorb a cockling of the paper caused by moisture absorption is formed on the surface. Yes. As a result, the paper being recorded can be held in a substantially flat shape, so that highly accurate recording can be performed.

  Further, a cutter groove 151 a extending in the main scanning direction is formed on the surface of the platen 151. The cutter groove 151a is sized so that the cutting edge of the cutter 154 protruding from the lower surface of the roll paper R can enter so that the cutter 154 does not damage the surface of the platen 151 when the roll paper R is cut in the width direction. Is formed. Thereby, the recording part and unrecorded part of the roll paper R can be reliably separated.

  The recording head 152 is disposed at a lower portion of the carriage 153 so as to face the cut paper or the roll paper R supplied to the upper surface of the platen 151 with a predetermined interval, and ejects two types of black ink. And a plurality of color ink recording heads for ejecting ink of each color such as cyan, magenta, yellow, red, blue, and gloss optimizer. The recording head 152 is provided with a pressure generating chamber and a nozzle opening connected to the pressure generating chamber, and a cut supplied to the upper surface of the platen 151 from the nozzle opening by storing ink in the pressure generating chamber and pressurizing it with a predetermined pressure. Controlled ink droplets are ejected toward the paper or roll paper R.

  The carriage 153 is placed on a carriage guide shaft 155 provided in the main scanning direction via a bearing (not shown), and is coupled to the belt 156. The carriage 153 is entrained by the movement of the belt 156 when the pulley 157 constituting the moving means is rotated by the carriage motor constituting the moving means (not shown) and the belt 156 constituting the moving means is rotated. Guided by 155, it reciprocates in the main scanning direction. As a result, the carriage 153 can be moved with high accuracy, so that highly accurate recording can be performed.

  The cutter 154 is disposed so as to be movable up and down in the vertical direction and movable in the main scanning direction so that the blade edge faces downward. The cutter 154 is moved up and down by, for example, a solenoid and moved in the main scanning direction together with the carriage 153. Therefore, it is not necessary to separately provide a means for moving the cutter 154, so that space can be saved and cost can be reduced. The cutter 154 may be separated from the carriage 153 and moved in the main scanning direction by a unique belt mechanism or a motor.

  The FFC has one end connected to the connector of the drive control unit 190 and the other end connected to the connector of the recording head 152, and sends a recording signal from the drive control unit 190 to the recording head 152. The ink tubes are provided for the inks of the respective colors, and one end of each ink tube is connected to the corresponding ink cartridge 10 via an ink pressurizing and supplying means (not shown), and the other end of each color recording head. 152 is connected. The ink tube is configured to send ink of each color pressurized by the ink pressure supply means from the ink cartridge 10 to the recording head 152.

  As shown in FIG. 4, the sheet suction unit 160 includes a pressure chamber 161 disposed in the lower part of the platen 151 and a fan (not shown) disposed in the lower part of the pressure chamber 161. The pressure chamber 161 is formed in a box shape in which a part of the upper surface and the bottom surface is opened, a platen 151 is attached to the open portion of the upper surface, and a fan is attached to the open portion of the bottom surface. By rotating the fan, the air is sucked into the pressure chamber 161 from the hole formed in the platen 151 and exhausted to the outside through the fan. Accordingly, when cut paper or roll paper R is supplied to the upper surface of the platen 151, negative pressure is generated on the lower surface side of the cut paper or roll paper R, so that the cut paper or roll paper R is attracted to the upper surface of the platen 151. As a result, the cut paper or the roll paper R can be prevented from being lifted, and the recording accuracy can be maintained with high accuracy.

  As shown in FIG. 4, the ink supply unit 170 includes a box-shaped cartridge storage unit 171 and a cartridge pressing unit 172 attached to the front side of the cartridge storage unit 171. The cartridge storage portion 171 is partitioned so that two types of ink cartridges 10 in total, including black, cyan, magenta, yellow, red, blue, and gloss optimizer, can be pulled out from the front side and pushed in sequentially from the left side of the figure. ing. The cartridge pressing portion 172 is attached to each partition portion of the cartridge storage portion 171 so as to be freely opened and closed. The cartridge pressing portion 172 presses the ink cartridge 10 in the partition portion in conjunction with the closing operation, and ink cartridges in the partition portion in conjunction with the opening operation. 10 is popping out.

  Here, the ink cartridge 10 is hermetically sealed, for example, in an outer case formed in a rectangular parallelepiped shape with a hard plastic material, for example, in a bag shape made of a flexible material and filled with ink inside. . In addition, an ink supply port connected to the ink tank and a positioning hole in the cartridge storage portion 171 are formed on the surface on the insertion side to the cartridge storage portion 171. On the other hand, an ink supply needle inserted into the ink supply port of the ink cartridge 10 and a positioning needle inserted into the positioning hole of the ink cartridge 10 are pulled out and pushed in the ink cartridge 10 on the inner rear surface of the cartridge housing portion 171. It is arrange | positioned so that it may protrude.

  Therefore, the ink cartridge 10 accommodated in the cartridge accommodating portion 171 is automatically positioned when the positioning needle is inserted into the positioning hole when the cartridge pressing portion 172 is closed. The ink can be supplied to the recording head 152 by entering the ink supply port. When the cartridge pressing portion 172 is opened, the positioning needle is automatically extracted from the positioning hole, and at the same time, the ink supply needle is automatically extracted from the ink supply port.

  The head characteristic recovery unit 180 is disposed below the carriage 153 located at the home position shown in FIG. 4, and includes a wiping unit, a capping unit, a suction unit, and a driving unit for these units. The wiping means includes a wiper formed in a substantially rectangular flat plate shape using rubber, felt, plastic, or the like, and rubs against the nozzle forming surface of the recording head 152 so as to wipe off ink adhering to the nozzle forming surface. It has become.

  The capping means is provided with a cap formed in a substantially rectangular parallelepiped shape with rubber, and a recess provided in the upper part is pressed against the nozzle forming surface of the recording head 152 to seal the nozzle opening. The suction means forcibly sucks and discharges ink in order to remove clogging of the nozzle openings and mixed bubbles. Therefore, it is possible to perform processing for maintaining the ink ejection characteristics of the recording head 152 in a constant state when the carriage 153 is in the home position.

  The waste ink collection unit 200 includes a detachable waste liquid cartridge 201. The waste liquid cartridge 201 stores waste liquid such as ink used when initially filling the ink supply system reaching the recording head 152 or cleaning liquid used when cleaning the ink supply system reaching the recording head 152. It has become. Accordingly, since the waste liquid processing can be completed only by replacing the waste liquid cartridge 201, the number of work steps can be reduced and contamination of the printer peripheral portion can be prevented.

  FIG. 5A is a plan view showing a platen 151 showing the characteristic part of the present invention and its peripheral part, FIG. 5B is a sectional view taken along the line A-A, and FIG. A cross-sectional view taken along line B-B and FIGS. 6A and 6B are cross-sectional views showing a state of adsorbing paper. As shown in FIG. 5, the platen 151 has ribs 52 having high heights and ribs 53 having low heights alternately formed at equal pitches p in the conveyance orthogonal direction (main scanning direction) of the sheet conveyance surface 51. That is, the formation pitch of the ribs 52 and 53 is p, and the formation pitch of only the high ribs 52 is 2p. The ribs 52 and 53 are formed in a rail shape having a trapezoidal cross section in the conveyance orthogonal direction and extending in the conveyance direction (sub-scanning direction).

  Suction holes 55 and 56 communicating with the pressure chamber 161 are formed in the bottom surface 54 a of the recess 54 between the ribs 52 and 53 and the upper surfaces 52 a and 53 a of the ribs 52 and 53. The recess 54 has a trapezoidal cross section in the conveyance orthogonal direction and is formed in a groove shape extending in the conveyance direction. The diameter of the suction hole 55 in the bottom surface 54 a of the recess 54 between the ribs 52 and 53 is formed larger than the diameter of the suction hole 56 in the upper surfaces 52 a and 53 a of the ribs 52 and 53. As a result, the amount of air movement is increased at the bottom surface 54a of the recess 54 between the ribs 52 and 53, so that the paper can be more attracted.

  Furthermore, as shown in FIG. 6, the bottom edges of the recesses 54 in which the side edges PE1 and PE2 of all the sizes and types of paper P1 and P2 used are located inside the adjacent high ribs 52 across the low ribs 53. The low rib 53 is formed so as to be sucked into the suction hole 55 of 54a. In particular, when an opening is formed at the position of the platen 151 corresponding to the side edge of the paper in order to collect the ink particles that have deviated from the edge of the paper when recording the paper without a border, the opening is provided. A low rib 53 is formed inside the portion. When the side edge portion of the sheet straddles the high rib 52, the inner side portion of the side edge portion is sucked into the suction hole 55 of the bottom surface 54a of the concave portion 54 located inside the high rib 52, and the side edge portion is May jump up. However, by making the side edge portion straddle the low rib 53, the side edge portion easily hangs down, and the side edge portion can be prevented from rising.

  According to the platen 151 having such a configuration, the conveyed paper is first sucked and recorded in the suction holes 56 of the upper surfaces 52a and 53a of the ribs 52 and 53, and then between the ribs 52 and 53. Is sucked into the suction hole 55 of the bottom surface 54a of the concave portion 54 of the concave portion 54. Accordingly, as shown in FIG. 6A, plain paper or proof paper P1, which is relatively weak, substantially follows the ribs 52, 53 and the concave portion 54 therebetween, and the generated pitch is relatively small. The cockling can be absorbed and, as shown in FIG. 6 (B), relatively stiff photographic paper, cardboard P2 and the like substantially conform to the high rib 52 and the recess 54 and the low rib 53 therebetween. As a result, the generated cockling having a relatively large pitch can be absorbed. For this reason, various paper sheets can be prevented from being lifted, and the distance between the recording surface of the paper and the nozzle forming surface of the recording head 152 can be kept substantially uniform, and recording unevenness and paper contamination can be prevented.

  In the above-described embodiment, the high ribs 52 and the low ribs 53 are alternately formed at an equal pitch p. However, the ribs 52 and 53 may be arbitrarily combined at an arbitrary pitch. . Further, although the lower rib 53 and the recess 54 are formed so as to surround the periphery, the higher rib 52 and the lower rib 53 may be formed side by side, and the higher rib 52, the lower rib 53 and the recess 54 are formed on the platen 151. You may form so that the edge part of a paper conveyance downstream may be reached.

  Further, the suction holes 55 and 56 are formed in the bottom surface 54a of the recess 54 between the ribs 52 and 53 and the upper surfaces 52a and 53a of the ribs 52 and 53, but the bottom surface of the recess 54 between the ribs 52 and 53 is formed. The suction hole 55 may be formed only in 54a. In addition, the diameter of the suction hole 55 in the bottom surface 54a of the recess 54 between the ribs 52 and 53 is formed larger than the diameter of the suction hole 56 in the upper surfaces 52a and 53a of the ribs 52 and 53. The suction holes 55 and 56 may have the same diameter.

  Further, since the conveyed paper is first sucked into the suction holes 56 of the upper surfaces 52a and 53a of the ribs 52 and 53, the suction holes 56 are sucked into the suction holes of the bottom surface 54a of the recess 54 between the ribs 52 and 53. It may be formed upstream of the sheet conveyance with respect to 55, that is, near the edge of the platen 151 on the sheet feed roller 141 side, so that the sheet is surely adsorbed first. Further, since the sheet is subsequently sucked into the suction hole 55 on the bottom surface 54a of the recess 54 between the ribs 52 and 53, the diameter of the suction hole 55 located on the most upstream side of the sheet conveyance among the suction holes 55 is set. The diameter of the suction holes 55 may be larger than that of the other suction holes 55 so as to generate a large suction force so as to reliably attract the paper. Furthermore, the peripheral portions of the suction holes 55 and 56 may be chamfered to increase the area and increase the suction force.

  FIG. 7 is a cross-sectional view showing a case where a problem occurs in the suction state of the paper. As described above, the low ribs so that the side edges of all the sheets used are sucked into the suction holes 55 on the bottom surface 54a of the recess 54 located inside the adjacent high ribs 52 across the low ribs 53. 53 is formed. For this reason, it is necessary to continuously form the low ribs 53 depending on the width of the paper to be used, and the high ribs 52 and the low ribs 53 cannot be formed alternately. This is particularly true when an opening is made at the position of the platen 151 corresponding to the side edge of the paper in order to collect ink particles that have fallen off the edge of the paper when recording the paper without a border. Occurs when the low rib 53 must be formed inside the opening.

  For example, as shown in FIG. 7, when three low ribs 53 are continuously formed, in a large sheet P3 covering these continuous ribs 53, the sheet portion conveyed on the sheet conveying surface 51 other than the continuous ribs 53 is The ribs 52 and 53 formed at the pitch p and the recesses 54 therebetween are substantially along. However, since the pitch of the sheet portion conveyed on the sheet conveying surface 51 of the continuous rib 53 cannot be maintained at p, it cannot substantially follow the continuous rib 53 and the recess 54 therebetween, and absorbs the generated cockling. I can't do that. For this reason, the paper P3 is lifted, and the interval between the recording surface of the paper P3 and the nozzle forming surface of the recording head 152 is non-uniform, which may cause uneven recording and paper contamination. Therefore, when the low ribs 53 are continuous at the side edge of the sheet, a pseudo high rib (hereinafter referred to as a pseudo rib) is formed to keep the pitch p. Here, when the low rib 53 is continuously formed at the side edge of the maximum usable paper, the pseudo rib does not need to be formed at the side edge of the maximum usable paper.

  FIG. 8 is a plan view showing the platen on which the pseudo rib, the high rib, and the low rib are formed, and a peripheral portion thereof. FIG. 9A is a cross-sectional view taken along the line AA showing the low rib and the like. ) Is a cross-sectional view taken along the line BB showing the pseudo rib and the like. As shown in FIG. 8, the platen 251 has ribs 352 having high heights and ribs 353 having high heights alternately formed at equal pitch p in the conveyance orthogonal direction (main scanning direction) of the sheet conveyance surface 351. In the portion where the low ribs 353 are continuous, the low ribs 353 and the pseudo ribs 357 are alternately formed at an equal pitch p.

  As shown in FIG. 9A, portions of the high rib 352 and the low rib 353 facing the recording head 152 (hereinafter referred to as upstream portions) 352a and 353a have a trapezoidal cross section in the conveyance orthogonal direction. It is formed in a rail shape extending in the direction (sub-scanning direction). The portions 352b and 353b on the downstream side of the paper conveyance from the upstream portions 352a and 353a (hereinafter referred to as the downstream portion) 352b and 353b are formed in a wedge shape that gradually decreases toward the edge of the platen 251 on the downstream side of the paper conveyance. Yes. That is, the upper surfaces 352aa and 353aa of the upstream portions 352a and 353a are formed as flat surfaces, and the upper surfaces 352ba and 353ba of the downstream portions 352b and 353b are edges of the upstream portions 352a and 353a from the upper surfaces 352aa and 353aa of the platen 251 on the downstream side of the sheet conveyance. It is formed in the inclined surface which goes down toward a part.

  Suction holes 355 and 356 communicating with the pressure chamber 161 are formed in the bottom surface 354a of the recess 354 between the ribs 352 and 353 and the upper surfaces 352aa, 353aa, 352ba, and 353ba of the ribs 352 and 353, respectively. The recess 354 has a trapezoidal cross section in the conveyance orthogonal direction and is formed in a groove shape extending in the conveyance direction. The diameter of the suction hole 355 of the bottom surface 354a of the recess 354 between the ribs 352 and 353 is formed larger than the diameter of the suction hole 356 of the upper surfaces 352aa, 353aa, 352ba, and 353ba of the ribs 352 and 353. As a result, a large suction force can be generated at the bottom surface 354a of the recess 354 between the ribs 352 and 353 to attract the paper.

  As shown in FIG. 9B, the pseudo rib 357 has a trapezoidal cross section in the conveyance orthogonal direction and is formed in a rail shape extending to the edge of the platen 251 on the downstream side of the sheet conveyance in the conveyance direction. In other words, the upper surface 357 a of the pseudo rib 357 is formed to be a flat surface up to the edge of the platen 251 on the downstream side of the sheet conveyance, which is the same as the height of the upper surface 353 aa of the upstream portion 353 a of the lower rib 353. The low rib 353 located on both sides of the pseudo rib 357, the recess 354 between the low rib 353 and the pseudo rib 357, and the suction holes 355, 356 are formed in the same structure as described above.

  According to the platen 251 having such a configuration, the pseudo ribs 357 are not maintained at the pitch p at the leading ends of the sheet portions conveyed on the sheet conveying surface 351 of the pseudo ribs 357 and the low ribs 353 located on both sides thereof. And the low ribs 353 located on both sides thereof and the recesses 354 therebetween cannot be substantially met. However, even if the leading edge of the paper portion corresponding to the low rib 353 located on both sides of the pseudo rib 357 passes through the flat upper surface 353aa of the low rib 353 and falls to the inclined upper surface 353ba, the pseudo rib 357 does not hang down. The leading end of the corresponding paper portion is supported by the flat upper surface 357a of the pseudo rib 357 and does not hang down.

  Therefore, since the leading edge of the paper portion corresponding to the pseudo rib 357 has a mountain shape, this mountain shape is transmitted from the leading edge of the paper portion to the rear, and the paper of the pseudo rib 357 and the low ribs 353 located on both sides thereof. The sheet portion conveyed on the conveying surface 351 substantially follows the pseudo ribs 357 formed at the pitch p, the low ribs 353 located on both sides thereof, and the recesses 354 therebetween. For this reason, the generated cockling is absorbed to prevent the paper from lifting, and the gap between the recording surface of the paper and the nozzle formation surface of the recording head 152 can be kept substantially uniform, thereby preventing uneven recording and paper contamination. be able to. In the case where the side edge of the paper straddles the pseudo rib 357, the height of the pseudo rib 357 is the same as the height of the rib 353, so that the side edge is likely to hang down, and the side edge is firmly attached. Can be adsorbed.

  FIG. 10A is a cross-sectional view taken along the line BB of FIG. 8 showing another example of the pseudo rib corresponding to FIG. 9, and the same components are denoted by the same reference numerals and description thereof is omitted. Of the pseudo rib 457, a portion (hereinafter referred to as an upstream portion) 457a immediately adjacent to the edge of the platen 251 on the upstream side of the sheet conveyance has a trapezoidal cross section in the conveyance orthogonal direction and extends in the conveyance direction (sub-scanning direction). It is formed in a rail shape. A portion 457b on the downstream side of the paper conveyance from the upstream portion 457a (hereinafter referred to as a downstream portion) 457b is formed in a wedge shape that gradually decreases toward the edge of the platen 251 on the downstream side of the paper conveyance. That is, the upper surface 457aa of the upstream portion 457a is the same as the height of the upper surface 352aa of the upstream portion 352a of the high rib 352 and is formed as a flat surface, and the upper surface 457ba of the downstream portion 457b extends from the upper surface 457aa of the upstream portion 457a It is formed in the inclined surface which goes down toward the edge part of a conveyance downstream side.

  According to the platen 251 having such a configuration, the leading edge of the sheet portion conveyed on the sheet conveying surface 451 of the pseudo rib 457 and the low ribs 353 located on both sides of the pseudo rib 457 and the pseudo rib 457 formed at the pitch p The lower ribs 353 located on both sides and the recesses 354 therebetween are substantially along. In this manner, by first attaching a ridge substantially along the pseudo rib 457, the low rib 353 located on both sides of the pseudo rib 457, and the recess 354 therebetween, the ridge is transmitted rearward from the front end of the paper portion. Therefore, even if the leading end of the paper portion passes through the flat upper surface 457aa of the pseudo rib 457 and shifts to the inclined upper surface 457ba, it does not sag. For this reason, the generated cockling is absorbed to prevent the paper from lifting, and the gap between the recording surface of the paper and the nozzle formation surface of the recording head 152 can be kept substantially uniform, thereby preventing uneven recording and paper contamination. be able to. If the side edge of the paper straddles the pseudo rib 457, the height of the pseudo rib 457 is gradually lowered, so that the side edge is likely to hang down, and the side edge is firmly adsorbed. Can do.

  FIG. 10B is a cross-sectional view taken along the line B-B in FIG. 8, showing still another example of the pseudo rib corresponding to FIG. 9. A portion (hereinafter referred to as an upstream portion) 557a of the pseudo rib 557 facing the recording head 152 is formed in a rail shape having a trapezoidal cross section in the conveyance orthogonal direction and extending in the conveyance direction (sub-scanning direction). . A portion 557b on the downstream side of the paper conveyance from the upstream portion 557a (hereinafter referred to as a downstream portion) 557b is formed in a wedge shape that gradually spreads toward the edge of the platen 251 on the downstream side of the paper conveyance. That is, the upper surface 557aa of the upstream portion 557a has the same height as the upper surface 353aa of the upstream portion 353a of the low rib 353, and the upper surface 557ba of the downstream portion 557b extends from the upper surface 557aa of the upstream portion 557a to the sheet of the platen 251. It is formed in the inclined surface which goes up until it becomes the same as the height of the upper surface 352aa of the upstream part 352a of the high rib 352 toward the edge part of a conveyance downstream side.

  According to the platen 251 having such a configuration, the pseudo rib 557 is not maintained at the pitch p at the leading end of the sheet portion conveyed on the sheet conveying surface 551 of the pseudo rib 557 and the low rib 353 located on both sides thereof. And the low ribs 353 located on both sides thereof and the recesses 354 therebetween cannot be substantially met. However, even if the leading end of the paper portion corresponding to the low rib 353 located on both sides of the pseudo rib 557 passes through the flat upper surface 353aa of the low rib 353 and then moves to the inclined upper surface 353ba and hangs down, the pseudo rib 557 The leading edge of the corresponding paper portion is projected into the inclined top surface 557ba of the pseudo rib 557 and has a mountain shape.

  Therefore, this mountain shape is transmitted from the leading end of the sheet portion to the rear, and the sheet portion conveyed on the sheet conveying surface 351 of the pseudo rib 557 and the low rib 353 located on both sides thereof is formed with a pitch p. The pseudo ribs 557, the low ribs 353 located on both sides of the pseudo ribs 557, and the recesses 354 therebetween are substantially aligned. For this reason, the generated cockling is absorbed to prevent the paper from lifting, and the gap between the recording surface of the paper and the nozzle formation surface of the recording head 152 can be kept substantially uniform, thereby preventing uneven recording and paper contamination. be able to. In the case where the side edge of the paper straddles the pseudo rib 557, the height of the upstream portion 557a of the pseudo rib 557 is the same as the height of the low rib 353, so that the side edge easily hangs down. The part can be adsorbed firmly.

  As described above, according to the ink jet printer 100 of the present embodiment, the ribs 52 and 53 are formed by combining the high ribs 52 and the low ribs 53 in the conveyance orthogonal direction of the paper conveyance surface 51, and sucked to the bottom surface 54 a between the ribs 52 and 53. Since the holes 55 are formed, the formation pitch p of the ribs 52 and 53 is formed in accordance with the pitch of the cock ring generated on the relatively weak paper, and the formation pitch 2p of the high ribs 52 is relatively strong. It can be formed in accordance with the pitch of cockling generated on the paper. Therefore, the relatively weak paper can be substantially along the ribs 52 and 53 and the recesses 54 between the ribs 52 and 53 regardless of the height of the ribs 52 and 53. On the other hand, the relatively stiff paper can be substantially along the high rib 52 and the recess 54 between the high ribs 52 without interfering with the low ribs 53. Therefore, even if the types of paper are different, the paper can be conveyed without being lifted.

  Further, the ribs 52 and 53 are formed at an equal pitch p, and the high ribs 52 and the low ribs 53 are alternately formed. Therefore, not only relatively weak paper but also relatively strong paper is used. Even if it is, cockling that occurs at substantially equal pitch can be reliably absorbed, and it supports cockling that occurs on relatively weak paper and cockling that occurs on relatively strong paper. be able to. Further, since the low rib 53 is formed so that the side edge of the paper is positioned on the low rib 53, the side edge of the paper that is relatively easy to lift can be drawn downward, and the paper is lifted from the side edge of the paper. Can prevent lifting. Further, since the suction holes 56 are formed in the upper surfaces 52a and 53a of the ribs 52 and 53, the entire sheet can be sucked and the sheet can be reliably prevented from being lifted. Further, since the artificially high ribs 357, 457, and 557 are formed so that the low ribs 353 are not continuous at the side edge portion of the paper other than the maximum used paper, the low ribs 353 must be continuously formed. Even if it is necessary, the low ribs 353 and the pseudo high ribs 357, 457, and 557 are alternately arranged, and cockling can be reliably absorbed.

  Any recording apparatus provided with a medium conveying apparatus can be applied to, for example, a facsimile apparatus and a copying apparatus. In addition to a recording apparatus, the meaning of a liquid ejecting apparatus that ejects a liquid corresponding to its use from a liquid ejecting head onto an ejected medium instead of ink and attaches the liquid to the ejected medium is, for example, a liquid crystal display or the like Color material jet head used for manufacturing color filters, electrode material (conductive paste) jet head used for electrode formation for organic EL display and surface emitting display (FED), bio-organic jet head used for biochip manufacturing, precision pipette The present invention can also be applied to an apparatus equipped with a sample ejection head or the like.

1 is a first perspective view of an external configuration example of an ink jet printer that is one of recording apparatuses according to an embodiment of the present invention, viewed from the front side. FIG. 3 is a second perspective view of an external configuration example of the printer of FIG. 1 viewed from the front side. It is the perspective view which looked at the printer of FIG. 1 from the back side. FIG. 2 is a perspective view showing an internal structure of the printer of FIG. 1. It is the top view which shows the platen which shows the characteristic part of this invention, and its peripheral part, AA sectional view, BB sectional drawing. It is sectional drawing which shows the adsorption | suction state of a paper. It is sectional drawing which shows the case where it becomes a problem in the adsorption | suction state of a paper. It is a top view which shows the platen in which the pseudo rib, the high rib, and the low rib were formed, and its peripheral part. FIG. 9 is a cross-sectional view taken along line AA showing a low rib and the like in FIG. 8 and a cross-sectional view taken along line BB showing a pseudo rib and the like. It is BB sectional drawing which shows another pseudo rib etc. of FIG.

Explanation of symbols

10 Ink cartridge, 51, 351, 451, 551 Paper transport surface, 52, 352 High rib, 53, 353 Low rib, 54, 354 Recess, 55, 56, 355, 356 Suction hole, 57, 357, 457, 557 Rib, 100 Inkjet printer, 110 Printer main body, 111 Upper housing, 112 Lower housing, 113 Main body cover, 114 Ink cover, 115 Operation panel, 120 Printer leg, 130 Roll paper storage, 140 Feed / discharge unit, 141 Paper feeding roller, 142 Paper feeding driven roller, 143 Paper feeding motor, 150 Recording unit, 151, 251 Platen, 152 Recording head, 153 Carriage, 154 Cutter, 155 Carriage guide shaft, 156 Belt, 157 Pulley, 158 Vibration absorbing means, 160 Paper suction , 161 a pressure chamber, 170 an ink supply unit, 171 cartridge receiving section, 172 cartridge pressing portion 180 head characteristics recovery section 190 the drive control unit, 200 the waste ink recovery unit

Claims (8)

A medium conveying device that conveys a medium while sucking the medium,
A medium transporting apparatus, characterized in that a high rib and a low rib are combined in the transport orthogonal direction of the medium transport surface, and suction holes are formed on the bottom surface between the ribs. The medium conveying apparatus according to claim 1, wherein the ribs are formed at an equal pitch. The medium conveying apparatus according to claim 1, wherein the high rib and the low rib are alternately formed. The medium conveying apparatus according to claim 1, wherein the low rib is formed so that a side edge portion of the medium is positioned on the low rib. The medium conveying apparatus according to any one of claims 1 to 4, wherein a pseudo high rib is formed at a place where the low rib is continuously formed. The medium conveying apparatus according to claim 1, wherein suction holes are also formed on an upper surface of each of the ribs. A recording device for recording on a recording medium,
A recording apparatus comprising the medium conveying apparatus according to claim 1. A liquid ejecting apparatus that ejects liquid onto a medium to be ejected,
A liquid ejecting apparatus comprising the medium conveying device according to claim 1.

Images