JP4487896B2 - Medium transport device - Google Patents

Description

  The present invention relates to a transport apparatus having transport rollers and toothed rollers arranged to face each other while sandwiching a transport target medium, and a liquid ejecting apparatus and a recording apparatus including the transport apparatus.

  An ink jet printer, which is one of recording apparatuses, records paper by ejecting ink onto the paper from the recording head while sandwiching and transporting the paper by a paper feed roller and its driven roller, and a paper discharge roller and its driven roller. Thus, the sheet is sandwiched and discharged. In such an ink jet printer, it may take time to dry the ink ejected onto the paper, and there is a possibility that the undried ink may be transferred to the surface of the driven roller of the paper discharge roller and contaminate the paper. . Therefore, the contact area with the paper is reduced by using a driven roller of the paper discharge roller as a so-called serrated roller with teeth provided around it, thereby preventing paper contamination due to ink transfer.

  However, when there is no sheet between the paper discharge roller and the jagged roller, the teeth of the jagged roller interfere with the friction body covering the surface of the paper discharge roller. In particular, when the friction body is made of soft rubber or the like, it will pierce the friction body, and if this state is repeated, irregularities will occur on the surface of the friction body, hindering the conveyance of the paper, or part of the friction body There is a risk of peeling off and adhering to the paper. On the other hand, when the friction body is made of hard ceramic or the like, the teeth will be worn, and if this state is repeated, the conveying capacity of the jagged roller will be reduced, or the contact area with the paper will become large and the paper will be contaminated by ink transfer. It cannot be prevented.

  In view of this, an ink jet printer has been proposed in which a groove having a width into which the teeth of the serrated roller can enter is formed so as to make one round of the friction body at a position facing the teeth of the friction body of the paper discharge roller. According to this, since the teeth of the serrated roller do not interfere with the friction body covering the surface of the paper discharge roller, it is possible to prevent paper conveyance failure and paper contamination due to frictional body damage and tooth wear ( Patent Document 1).

JP-A-9-86749

  In the above-described conventional ink jet printer, the paper that has entered between the paper discharge roller and the jagged roller is pressed by the jagged roller while being supported by both edges of the groove. Will bend toward For this reason, the sheet cannot be brought into contact with the friction body of the paper discharge roller with sufficient pressure, and a sufficient frictional force cannot be generated between the paper and the friction body of the paper discharge roller. Therefore, there is a possibility that the target sheet conveying force cannot be obtained. Furthermore, since the paper is rubbed against both edges of the groove, there is a risk of scratches. In particular, in the case of a postcard or the like that performs double-sided recording, the recording quality may deteriorate.

  The present invention has been made in view of the various problems as described above, and an object thereof is to prevent deterioration of the conveyance roller and the toothed roller when the medium to be conveyed is conveyed by the conveyance roller and the toothed roller. Another object of the present invention is to provide a transport apparatus that can obtain a sufficient transport force and can eliminate damage to the transport medium, and a liquid ejecting apparatus and a recording apparatus that include the transport apparatus.

  To achieve the above object, in the transport apparatus of the present invention, the pitch of teeth formed on the toothed roller in the transport apparatus having the transport roller and the toothed roller arranged to face each other while sandwiching the transported medium. Are formed on the outer circumference of the transport roller. As a result, even if the transported medium is sandwiched between the transport roller and the toothed roller, the transported medium is prevented from being bent in the concave portion, and the transported medium can be brought into contact with the transport roller with sufficient pressure. It is possible to generate a sufficient frictional force between the medium to be transported and the transporting roller to obtain a target transporting force. Further, since the edge of the concave portion of the conveying roller is not formed on the entire circumference of the roller, the area where the medium to be conveyed is rubbed by the edge of the concave portion is reduced, so that damage to the medium to be conveyed can be reduced.

  Further, the concave portion is formed in a shape in which the tooth tip does not interfere when the tooth enters. Thereby, even when a to-be-conveyed medium does not exist between a conveyance roller and a toothed roller, damage to a toothed roller and a conveyance roller can be eliminated. Further, the transport roller is a discharge roller for discharging the transported medium. Thus, for example, even after a liquid such as ink is ejected onto the transported medium, the transported medium can be discharged to the outside without disturbing the ejection state of the liquid such as ink on the transported medium. it can.

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

  Embodiments of the present invention will be described with reference to the drawings. The embodiments described below do not limit the invention according to the claims, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent.

  FIG. 1 is a perspective view showing the entire external configuration of an ink jet printer that is one of recording apparatuses according to an embodiment of the present invention, FIG. 2 is a perspective view showing its internal structure, and FIG. It is a schematic side view which shows an internal structure. The ink jet printer 100 includes, for example, business cards, cards, L / 2L size, postcards, six-cut sheets, and JIS standard A6 size to A4 size cut paper (conveyed medium), for example, CD-R ( It has a function capable of recording on the label surface of an optical disc such as Compact Disc-Recordable (DVD) and DVD-R (Digital Versatile Disc-Recordable).

  As shown in FIG. 1, the ink jet printer 100 is entirely covered with a substantially rectangular parallelepiped housing 101. An operation unit 110 is disposed on the front side of the upper surface of the housing 101, a memory card slot 120 is disposed on the right side of the front surface of the housing 101, and a paper feeding unit 130 is disposed on the rear side of the upper surface. A paper discharge unit 140 is disposed on the front side. Further, as shown in FIGS. 2 and 3, a paper conveyance unit (conveyance device) 150 including a characteristic part of the present invention, a recording unit 160, and a disk conveyance unit 200 are disposed inside the housing 101. Yes.

  As shown in FIG. 1, the operation unit 110 includes a substantially rectangular operation panel 111, and a liquid crystal panel 112 that displays an operation state or the like is disposed at a substantially central portion of the operation panel 111. Buttons 113 such as a power system for turning on / off the power, an operation system for operating the cueing of paper or operating ink flushing, a processing system for performing image processing, and the like are disposed on both sides. Since the user can operate the button 113 while checking the liquid crystal panel 112 for confirmation, an erroneous operation can be prevented.

  As shown in FIG. 1, the memory card slot 120 is covered with a cover 121 that can be opened and closed in the direction of the arrow a. The memory card slot section 120 includes a slot section (not shown) in which, for example, three slots are formed, and is configured to be compatible with 13 types of memory cards. Even if the user does not connect the ink jet printer 100 to a personal computer, the user can record an image or the like stored in the memory card only by inserting the memory card into the slot of the slot portion with the ink jet printer 100 alone. Can do.

  As shown in FIG. 1, the paper supply unit 130 has a function of opening and closing a paper supply port 131 that opens upward in a rectangular shape and a function of supporting one or a plurality of papers to be supplied. 132 is provided. The paper support 132 is attached so as to be rotatable in the direction of the arrow b shown in the figure around the rotation axis at the rear end. When the user uses or does not use the inkjet printer 100, the user inserts a finger into the hole 133 provided in the housing 101 on the left side of the paper support 132 and opens and closes the paper support 132 with the left side of the paper support 132 shown. Therefore, it is possible to easily insert a sheet, and to prevent dust from entering the sheet feeding port 131.

  As shown in FIG. 2, the paper support 132 includes a first support 31 and a second support 32 that support the back surface of the paper, a fixed edge guide 33 that guides both side edges of the paper, a movable edge guide 34, and the like. ing. The first support 31 is formed in a flat plate shape and is attached so as to be rotatable in the direction of the arrow b shown in the drawing with the rotation axis at the rear end as a center. The second support 32 is formed in a flat plate shape and is disposed in the first support 31 so as to be retractable and retractable. As a result, various sizes of paper can be reliably supported during use, and when not in use, the second support 32 is stored in the first support 31, and the first support 31 is placed over the paper feed slot 131. It can be stored compactly.

  The fixed edge guide 33 is formed integrally with the hopper 51 in a shape along the right side wall in the figure, and the movable edge guide 34 is formed in a shape along the left side wall in the figure, and the rear wall is substantially between the left side wall and the right side wall. It is attached so that it can move in parallel. Since the fixed edge guide 33 and the movable edge guide 34 can reliably guide both side edges of the paper even if the paper sizes are different, the feeding can be performed with high accuracy.

  As shown in FIG. 1, the paper discharge unit 140 is a stacker that has a function of opening and closing a paper discharge port 141 that opens in a rectangular shape toward the front, and a function of stacking one or a plurality of paper to be discharged. 142. The stacker 142 is attached so as to be rotatable in the direction of the arrow c in the figure around the rotation axis at the lower end. When the user uses or does not use the ink jet printer 100, the user can open and close the stacker 142 by placing a finger on the handle 143 provided on the top of the stacker 142, so that the setting can be easily performed. In addition, dust can be prevented from entering the paper discharge outlet 141. Further, since the recorded paper is always discharged from the front side, the user can easily take out the paper.

  As shown in FIG. 2, the stacker 142 includes a first stacker 41 and a second stacker 42. The first stacker 41 is formed in a flat plate shape, and is attached so as to be rotatable in the direction of the arrow c in the figure around the rotation shaft at the rear end. The second stacker 42 is formed in a flat plate shape and is disposed in the first stacker 41 so as to be retractable and retractable. As a result, sheets of paper of various sizes can be stacked and placed reliably when in use, and the second stacker 42 is stored in the first stacker 41 and the first stacker 41 is discharged when not in use. Since it covers the paper mouth 141, it can be stored compactly.

  The paper transport unit 150 is disposed from the paper feed unit 130 to the paper discharge unit 140, and includes an automatic paper feed mechanism 151, a transport mechanism 152, and a paper discharge mechanism 153 including the characteristic portions of the present invention. Yes. The automatic paper feed mechanism 151 is a hopper 51 that lifts up the paper supported by the paper support 132, a paper feed roller 52 that picks up the paper lifted by the hopper 51, and multi-feed by the paper feed roller 52. A retard roller 53 that separates the separated paper into only one sheet, a paper return lever 54 that returns the remaining paper separated by the retard roller 53 to the hopper 51, and the like.

  The hopper 51 is formed in a flat plate shape on which paper can be placed, and is disposed substantially parallel to the rear wall. The lower end is located near the paper feed roller 52 and the upper end is located near the top of the rear wall. It is arranged to do. The hopper 51 is attached such that the other end of a compression spring (not shown) having one end attached to the rear wall is attached to the back surface on the lower end side, and the lower end side turns around the upper end side by expansion and contraction of the compression spring. It is installed.

  The paper feed roller 52 is formed in a D shape with a part of the cross-section cut away, and is disposed in the vicinity of the lower end of the hopper 51. The paper feed roller 52 rotates intermittently and frictionally feeds the paper lifted by the hopper 51. It is supposed to send. The retard roller 53 is disposed so as to come into contact with the paper feed roller 52, and when the paper is fed by the paper feed roller 52, only the uppermost paper is frictionally separated from the lower paper. Yes. The paper return lever 54 is formed in a claw shape and is disposed in the vicinity of the paper feed roller 52, and the lower layer paper separated by the retard roller 53 is placed on the claw and returned to the hopper 51.

  The transport mechanism 152 is provided with a paper feed roller 55 that feeds paper in the sub-scanning direction in synchronization with the recording operation, a driven roller 56, and the like. The paper feed roller 55 is arranged on the upstream side of the transport of the platen 163, and sandwiches the paper fed by the paper feed roller 52 together with the driven roller 56 and feeds it to the platen 163.

  The paper discharge mechanism 153 includes a paper discharge roller (conveying roller (discharge roller)) 57, a first jagged roller 58a, a second jagged roller (toothed roller) 58b, and the like. The first knurled roller 58a is disposed on the downstream side of the transport of the platen 163, and the second knurled roller 58b and the paper discharge roller 57 are disposed on the downstream side of the transport of the first knurled roller 58a and pass through the platen 163. The incoming paper is first discharged by the first knurled roller 58a, and then is nipped by the second jagged roller 58b and the paper discharge roller 57 and discharged onto the stacker 142. The details of the paper discharge roller 57 and the second jagged roller 58b, which are characteristic parts of the present invention, will be described later.

  The recording unit 160 includes a carriage 161 that moves in the main scanning direction in synchronization with the recording operation, a recording head 162 that ejects ink in synchronization with the recording operation, and a platen 163 that holds the recording paper flat. Has been. The carriage 161 is inserted into the carriage guide shaft 164 above the platen 163 and connected to the carriage belt 165. When the carriage belt 165 is actuated by a carriage motor (not shown), the carriage 161 is entrained in the movement of the carriage belt 165. It is guided by the shaft 164 so as to reciprocate. The carriage 161 is formed with a cartridge housing portion 61 into which a plurality of ink cartridges can be inserted and removed.

  The recording head 162 is mounted on the carriage 161 at a predetermined distance from the platen 163. For example, the recording head for black ink that discharges black ink, and five colors of yellow, cyan, light cyan, magenta, and light magenta. And a plurality of color ink recording heads for ejecting the respective inks. The recording head 162 is provided with a pressure generating chamber and a nozzle opening connected to the pressure generating chamber. The size of the recording head 162 is controlled from the nozzle opening toward the sheet by storing ink in the pressure generating chamber and pressurizing the ink with a predetermined pressure. Ink droplets are discharged.

  FIG. 4 is a perspective view showing details of the paper discharge roller 57 and the second serration roller 58b, and FIG. 5 is a side view thereof. The paper discharge roller 57 includes a roller shaft 57a made of plastic or metal, and a friction body 57b made of rubber or the like fitted into the roller shaft 57a. The second serrated roller 58b is made of metal or the like, and serrated serrated (tooth) 58bb is formed at a constant pitch around the second serrated roller 58b. A concave portion 57bb into which the toothed portion 58bb of the second toothed roller 58b can enter one tooth at a time is formed so as to make a round of the friction body 57b at a position facing the toothed portion 58bb of the friction body 57b of the paper discharge roller 57. Yes. The recesses 57bb are formed as quadrangular pyramid-shaped depressions, and are arranged in a line in the circumferential direction at the same pitch as the pitch of the serrations 58bb.

  By providing such a recess 57bb on the friction body 57b of the paper discharge roller 57, as shown in the enlarged view of FIG. 5, when the serration 58bb of the second serration roller 58b enters into the recess 57bb, the serration 58bb becomes the recess 57bb. There is no interference. Accordingly, even when there is no sheet between the paper discharge roller 57 and the second jagged roller 58b, the frictional body 57b of the paper discharge roller 57 is not damaged by the jagged 58bb of the second jagged roller 58b. Further, even when the friction body 57b is made of ceramic or the like, the friction body 57b does not cause wear of the serrations 58bb.

  Here, the smooth curved portion at the base of the serrated portion 58 bb is in contact with the smooth curved portion at the edge portion of the recessed portion 57 bb, which is necessary for causing the second serrated roller 58 b to follow the rotation of the paper discharge roller 57. With this, the friction member 57b of the paper discharge roller 57 is not damaged by the serration 58bb of the second serration roller 58b. In addition, as a positioning configuration in the height direction of the second serrated roller 58b at this time, height regulation by a holder that fixes the second serrated roller 58b to a frame (not shown), or a peak between the recesses 57bb is a trough between the serrated 58bb. The height regulation by receiving in can be considered.

  Further, even if the paper is sandwiched between the paper discharge roller 57 and the second jagged roller 58b, the paper does not bend in the concave portion 57bb, so that the paper can be brought into contact with the paper discharge roller 57 with sufficient pressure. A sufficient frictional force can be generated between the paper and the paper discharge roller 57 to obtain a desired conveying force. Further, since the sheet is not rubbed at the edge of the recess 57bb, the sheet is not damaged, and the recording quality is not deteriorated even in the case of a postcard or the like that performs double-sided recording.

  In the above-described embodiment, the shape of the recess 57bb is a quadrangular pyramid-shaped depression. However, the present invention is not limited to this. For example, a cylinder, a cone, a prism, a pyramid, a wedge, etc. Any shape such as a semi-spherical or semi-elliptical sphere may be used. Similarly, although the shape of the serrations 58bb is serrated, the present invention is not limited to this, and any shape that does not interfere with the recesses 57bb, for example, a triangle, a quadrilateral polygon, a semicircular shape, a semielliptical shape, a waveform, etc. Any shape can be used. In the present embodiment, the case where the present invention is applied to the paper discharge roller 57 and the second jagged roller 58b has been described. However, any roller may be used as long as it is opposed to the paper feed roller 55 and its driven roller 56, for example. Is also applicable.

  An operation when recording on a sheet in such a configuration will be described. The user stores a plurality of sheets before recording in the paper support 132 and activates the ink jet printer 100. The lower end of the paper stacked and stored in the paper support 132 is lifted by the hopper 51 and brought into contact with the paper feed roller 52. At the same time, the paper is fed by the paper feed roller 52 and, at the same time, only the uppermost paper is frictionally separated and fed by the separation pad 53.

  The uppermost sheet is skewed and cueed, and is nipped by the sheet feed roller 55 and its driven roller 56 and fed to the platen 163. The sheet is recorded by a recording head 162 mounted on a carriage 161 scanned by a carriage motor and a carriage belt 165. At this time, the control unit of the ink jet printer 100 supplies each color ink from a total of six color ink cartridges, for example, yellow, magenta, light magenta, cyan, light cyan, and black, to the recording head 162, and discharge timing of each color ink and carriage 161 and the paper feed roller 55 are controlled to execute highly accurate ink dot control, halftone processing, and the like.

  Then, the recording-completed paper is sandwiched and placed on the stacker 142 by being sandwiched by the first discharge roller 57 and the second protrusion roller 58b from the first protrusion roller 58a. At this time, the paper sandwiched between the paper discharge roller 57 and the second knurled roller 58 b is not bent by the concave portion 57 bb of the friction body 57 b of the paper discharge roller 57. It can be contacted by pressure. Therefore, a sufficient frictional force can be generated between the paper and the paper discharge roller 57, and a desired conveying force can be obtained and the paper can be discharged with high accuracy. Further, since the paper is not rubbed at the edge of the recess 57bb, the paper is not damaged, and high-precision recording can be maintained even in the case of postcards that perform double-sided recording.

  For example, a facsimile apparatus, a copying apparatus, a scanner, and the like can be applied as long as the recording apparatus includes a conveyance device. 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 perspective view showing an overall appearance configuration of an ink jet printer that is one of recording apparatuses according to an embodiment of the present invention. FIG. 2 is a perspective view showing an internal structure of the printer of FIG. 1. It is a schematic side view which shows the internal structure of the printer of FIG. FIG. 2 is a perspective view showing details of a paper discharge roller and a second serrated roller of the printer of FIG. 1. FIG. 5 is a side view of FIG. 4.

Explanation of symbols

57 Paper discharge roller, 57a Roller shaft, 57b Friction body, 57bb Concavity, 58b 2nd roller, 58bb roller, 100 Inkjet printer, 101 Housing, 110 Operation part, 120 Memory card slot part, 130 Paper feed part, 140 Paper discharge Section, 150 paper transport section, 160 recording section, 200 disk transport section

Claims (1)

In a transport apparatus having transport rollers and toothed rollers arranged to face each other while sandwiching a transported medium,
Concave portions having the same pitch as the tooth pitch formed on the toothed roller are formed on the outer periphery of the conveying roller ,
The depth of the recess is formed deeper than the height of the tooth,
The tooth bottom of the toothed roller is formed as a concave curved surface in the rotational direction of the toothed roller,
The conveying device , wherein an edge of the concave portion is in contact with the curved surface, and the teeth do not contact an outer periphery of the conveying roller .

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