JP5769492B2 - Recording device - Google Patents

Description

The present invention relates to a record apparatus.

  2. Description of the Related Art In a recording apparatus such as a printer in which a plurality of paper conveyance roller pairs are arranged before and after the conveyance direction with respect to a recording head that records an image on a recording sheet, a roller pair in which the trailing edge of the recording sheet is arranged upstream of the recording head There is a problem that the conveyance accuracy of the recording sheet is lowered when passing through. This is because when the trailing edge of the recording sheet is released from the nip of the upstream roller pair, the driven roller urged toward the conveying roller kicks the trailing edge of the recording sheet. Patent Document 1 discloses a technique in which a mechanism for changing the transport force is provided on each of the upstream transport roller and the downstream transport roller, and transport is performed by changing the transport force at an arbitrary position.

JP 2001-278494 A

By the way, as one of the causes that the recording sheet conveyance accuracy decreases when the trailing edge of the recording sheet passes through the roller pair, it has been found that there is a deflection of the conveying roller in addition to the trailing edge repelling by the roller pair. . Specifically, when the recording sheet is conveyed by two conveying rollers arranged on the upstream side and the downstream side, a tensile force or repulsion is exerted on the recording sheet via the recording sheet due to a difference in speed between the two conveying rollers. Force is generated. Deflection of the conveying direction of the conveying rollers generated by this force is released and the trailing edge of the recording sheet from the nip by Russia over roller pair exits, thereby resulting in moving only the recording sheet recovery amount of the conveying roller.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a recording apparatus capable of suppressing a decrease in recording sheet conveyance accuracy.

The recording apparatus according to the present invention includes a recording unit that records an image on a sheet, and a first unit that is disposed upstream of the recording unit in the sheet conveyance direction and intermittently conveys the sheet by repeating conveyance and stoppage of the sheet . a transport roller, is pressed against the first conveying roller, a first driven roller which rotates following the first conveying roller, the arranged in the conveying direction on the downstream side of the recording unit, the sheet a second conveying roller that conveys, is pressed against the second transport roller, and a second driven roller which rotates following the second conveying roller, the first conveying roller and the second conveyance In a state where the sheet is intermittently conveyed by the roller, a first operation of pressing the second driven roller again after releasing the pressing of the second driven roller, and the first operation after the first operation And a control unit that executes a second operation for releasing the pressing of the driven roller, wherein the control unit causes the trailing edge of the sheet to move with the first transport roller by a next transport operation. When it is determined that the sheet passes through the nipping part between the first driven roller and the first driven roller, the first operation and the second operation are performed while the sheet is stopped before the next conveyance operation is performed. And the next transport operation is executed after the second operation is completed .

  According to the present invention, before the trailing edge of the sheet is released from the nip of the roller pair, it is possible to reduce the deflection generated in the roller that conveys the sheet by reducing or releasing the pressing force. As a result, it is possible to suppress a decrease in conveyance accuracy when the trailing edge of the sheet is released from the nip by the roller pair.

FIG. 3 is a perspective view of a mechanism unit of the recording apparatus according to the first embodiment of the invention. FIG. 2 is a perspective view illustrating a press-contact force releasing mechanism unit of the recording apparatus in FIG. 1. FIG. 2 is a cross-sectional view showing a pressure contact / pressure contact release state of a pressure contact force release mechanism portion of the recording apparatus of FIG. 1. FIG. 2 is a block diagram illustrating a schematic configuration of a control system of the recording apparatus in FIG. 1. FIG. 2 is a schematic diagram illustrating a state of a recording sheet and each transport mechanism element in the recording apparatus of FIG. 1. 2 is a control flowchart of the recording apparatus of FIG. FIG. 2 is a schematic diagram illustrating a state of a transport mechanism element in each control operation state in the recording apparatus of FIG. 1. The perspective view which showed the press-contact force cancellation | release mechanism part of the recording device which concerns on 2nd Embodiment of this invention. FIG. 9 is a cross-sectional view showing a pressure-contact / pressure-release state of the pressure-contact force releasing mechanism portion of FIG. FIG. 9 is a control flowchart in the recording apparatus of FIG. 8. FIG. 9 is a schematic diagram illustrating a state of a transport mechanism element in each operation of the recording apparatus in FIG. 8.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, the configuration of the recording apparatus will be described. FIG. 1 is a perspective view of a mechanism portion of the recording apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the pressure contact force releasing mechanism in the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a pressure-contact / pressure-release state of the pressure-force releasing mechanism in the first embodiment of the present invention.

  The recording apparatus according to the present embodiment includes a recording unit 1 that scans in a direction orthogonal to the recording sheet conveyance direction and records an image on the recording sheet. This is an ink jet recording apparatus that forms an image by repeatedly performing a recording operation by the unit 1. The recording apparatus includes a sheet feeding unit 2 that feeds a recording sheet to a conveyance mechanism unit, and a conveyance roller 3 (a first mechanism) that conveys a recording sheet downstream as a conveyance mechanism unit in the conveyance direction of the sheet feeding unit. The paper discharge roller 4 (second transport roller) is disposed so that the transport roller) further sandwiches the recording head in the transport direction on the downstream side. An edge sensor (not shown) for detecting the leading and trailing edges of the recording sheet is provided between the paper feeding unit 1 and the conveying roller 3, and the recording unit 1 is provided between the conveying roller 3 and the paper discharging roller 4. A platen 12 is provided for maintaining a proper distance from the recording sheet.

  Next, details of the transport mechanism will be described. The conveyance roller 3 extends in a direction orthogonal to (intersects) the conveyance direction of the recording sheet, is supported rotatably about a predetermined rotation axis, and is on the surface (conveyance surface) of a metal shaft that can contact the recording sheet. A roller coated with ceramic fine particles. A plurality of pinch rollers 5 (first driven members) as driven rollers are provided in contact with the conveying roller 3. The pinch roller 5 is held by a pinch roller holder 7 and is pressed against the conveying roller 3 by an urging force of a pinch roller spring 8, and a recording sheet conveying force is generated by a frictional force.

  On the other hand, the paper discharge roller 4 extends in a direction orthogonal to (crosses) the conveyance direction of the recording sheet, is supported to be rotatable about a predetermined rotation axis, and is formed on a metal shaft having a diameter of ½ of the conveyance roller 3. And having a plurality of rubber portions in contact with the carrier medium. The outer peripheral surface of the rubber portion is a conveyance surface that can come into contact with the recording sheet. Here, the discharge roller 4 has a sectional moment of 1/8 that contributes to rigidity due to the diameter ratio with the transport roller 3, and the amount of deflection when the same load is applied is eight times larger. The paper discharge roller 4 is set so that the conveyance amount per unit rotation angle is smaller than that of the conveyance roller 3. Here, for the sake of explanation, the conveyance amount is set to be small, but the present invention is not limited to this. This can be easily carried out by taking a method such as making the outer diameter of the paper discharge roller 4 smaller than the outer diameter of the transport roller 3. Further, the end of each roller is supported so that the conveyance roller 3 and the paper discharge roller 4 have the same width. The paper discharge roller 4 is provided with a plurality of spurs 6 (second driven members) in contact with the outer peripheral surface thereof. The spur 6 has a through hole in the central axis, and a spur spring 10 in the shape of a coil spring having a function as a rotation support shaft and a function of applying a pressure contact force is inserted into the through hole. The spur 6 is pressed against the paper discharge roller 4 by the urging force of the spur spring 10, and the recording sheet conveyance force is generated by the frictional force. Further, a push spur 11 is provided upstream of the spur 6 for suppressing the floating of the recording sheet and guiding the leading end of the recording sheet to the paper discharge roller 4. Both the spur springs 10 of the spur 6 and the pushing spur 11 are held by a spur holder 9 and are configured to be held by the spur holder 9 via the spur spring 10. In the present embodiment, one discharge roller is used. However, for the purpose of preventing the recording sheet from being lifted, two discharge discharge rollers using assist discharge rollers with weaker conveying force than the main discharge roller are used. The paper discharge roller configuration may be used. In this case, since the assist discharge roller hardly contributes to the conveyance of the recording sheet, it is not necessary to consider whether or not the pressing force of the assist discharge roller is released.

  Next, the pressure release mechanism portion will be described. The spur holder 9 is guided in such a manner that it can be moved up and down while being fixed in the conveyance direction of the recording sheet. The vertical movement position is regulated by abutting against the figure. As a result, an appropriate distance from the paper discharge roller 4 is maintained. A spur holder cam portion 91 is formed on the spur holder 9. A spur holder lift cam 92 having an eccentric cam shape is provided below the spur holder cam portion 91. The spur holder lift cam 92 is fixed to the spur holder lift cam shaft 93. Similarly, a spur holder lift gear 94 is fixed to the spur holder lift camshaft 93. In a normal state, the spur holder lift cam 92 is configured not to contact the spur holder cam portion 91 as shown in FIG. When a drive unit (not shown) rotates the spur holder lift gear 94, the spur holder lift cam 92 rotates to the state shown in FIG. The spur 6 can be separated from the paper discharge roller 4. By adopting such a configuration, it is possible to provide a mechanism in which the spur 6 is separated from the paper discharge roller 4 while ensuring the positional accuracy between the spur 6 and the paper discharge roller 4 during normal conveyance.

  Next, the drive unit of the transport mechanism unit will be described. Driving to the transport roller 3 is performed by transmitting the rotational force of a transport motor (not shown) formed of a DC motor to a transport roller gear 13 provided on the shaft of the transport roller 3. A conveyance code wheel 14 is directly connected to the axis of the conveyance roller 3, and a roller encoder sensor (not shown) provided on the main body side of the recording apparatus reads the rotation amount of the conveyance code wheel to thereby convey the conveyance roller 3. The position is detected. The rotation driving of the transport roller gear 13 is transmitted to the paper discharge roller gear 15 via the idler gear 15. The paper discharge roller gear 15 is fixed to the paper discharge roller 4 so that the transport roller 3 and the paper discharge roller 4 are driven simultaneously.

  FIG. 4 is a block diagram showing a schematic configuration of a control system of the recording apparatus according to the first embodiment of the present invention. The control system of the recording apparatus includes a CPU 401 that controls the operation of each unit and data processing, a ROM 402 that stores data executed by the CPU 401, and a RAM 403 that stores processing data executed by the CPU 401 and data received from the host computer 406. It is installed. The CPU 401, ROM 402, and RAM 403 are connected to a plurality of motors 404 typified by a conveyance motor, a recording unit 1 that performs image recording, and a plurality of sensors 405 typified by edge sensors and roller encoder sensors. I do.

  Next, a mechanism of occurrence of the deflection of the roller due to the difference in conveyance speed between the rollers will be described. FIG. 5 is a diagram illustrating a state of the recording sheet and each transport mechanism element in the recording apparatus according to the present embodiment. FIG. 5 (a) shows the state when printing the leading edge of the recording sheet, FIG. 5 (b) shows the state when printing a so-called normal area other than the leading and trailing edges, and FIG. 5 (c) shows the trailing edge. Indicates the state when printing. The explanation will be made along the flow of printing on the recording sheet.

  Since the recording sheet fed by the sheet feeding unit 2 is first printed at the leading end, recording is performed in a state as shown in FIG. When image recording progresses and the leading edge of the recording sheet P reaches the paper discharge roller 4, the recording sheet P is conveyed by two conveyance rollers by the conveyance roller 3 and the paper discharge roller 4 as shown in FIG. Become. As described above, in the conveyance of the recording sheet between the two conveyance rollers, the deflection of the roller due to the speed difference between the rollers occurs.

  In the present embodiment, the discharge roller 4 is set to have a smaller conveyance amount per unit rotation angle than the conveyance roller 3, so the conveyance roller 3 moves the discharge roller 4 through the recording sheet in the conveyance direction. The paper discharge roller 4 is pushed downstream and receives the assist force from the transport roller 3, so that the transport amount per unit rotation angle is apparently increased. In the present embodiment, the recording sheet is assumed to be a relatively thick sheet such as a photographic paper which is not easily buckled even when a compression force is applied between the rollers.

  On the other hand, the conveyance roller 3 receives the reaction force exactly the same as the force pushing the paper discharge roller 4 downstream, and the conveyance roller 3 apparently has a small conveyance amount per unit rotation angle. The transfer of force through the recording sheet is performed until the conveyance amount per unit rotation angle of each conveyance roller becomes equal, and finally the conveyance amount of the recording sheet is the same between the conveyance roller 3 and the discharge roller 4. The force acting between the two conveying rollers is applied to each roller as a distributed load over the entire width region of the recording sheet, and bends the conveying rollers. Although equal force is applied to the transport roller 3 and the paper discharge roller 4, as described above, the paper discharge roller 4 is configured to be easily deflected 8 times as much as the transport roller 3 because of the rigidity of the roller. As shown in FIG. 4, the conveyance roller 3 is in a state in which there is almost no deflection with respect to the paper discharge roller 4.

  When the image recording progresses and the trailing edge of the recording sheet P reaches the nip portion between the conveying roller 3 and the pinch roller 5, the force that has been passed through the recording sheet at the timing when the trailing edge of the recording sheet passes through the nip portion. The flexure of the two transport rollers is released. Since this deflection occurs in the transport direction, the recording sheet is moved in the transport direction. This is a restoring operation from the deflection state of the roller that occurs when the trailing edge of the recording sheet passes through the nip portion.

  As shown in FIG. 5C, the recording sheet whose rear end has passed through the nip portion is transported only by the paper discharge roller 4 to perform a recording operation. Needless to say, at this time, the conveyance roller 3 does not sandwich the recording sheet, so that no deflection occurs in the roller.

  In the present embodiment, the case where the discharge roller 4 bends toward the downstream side by setting the conveyance amount of the discharge roller 4 to be smaller than the conveyance roller 3 has been described. However, it can be easily understood that if the transport amount of the paper discharge roller 4 is set larger than that of the transport roller 3, the direction of the force is reversed and the direction of deflection is changed. In addition, it is easy to change the deflection ratio of each conveyance roller by changing the rigidity of the conveyance roller, and the rigidity of the conveyance roller is reduced by reducing the rigidity of the conveyance roller with respect to the discharge roller. May be. However, in that case, it is necessary to release the pressure contact force on the conveying roller side.

Next, a control flow during recording according to the present embodiment will be described. FIG. 6 is a flowchart of the control operation in the first embodiment of the present invention. FIG. 7 is a diagram showing the state of the transport mechanism element in each control operation state according to the first embodiment of the present invention. When a recording command is issued, a paper feeding operation is first performed by the paper feeding unit 1 (501). When the leading edge of the fed recording sheet P is detected by the edge sensor, the transport motor rotates and the transport roller 3 starts rotating (in the present embodiment, the paper discharge roller 4 also starts rotating simultaneously). When the leading end portion of the recording sheet P reaches the nip portion between the conveying roller 3 and the pinch roller 5, a predetermined registration operation is performed, and the leading end portion of the recording sheet P is conveyed to the recording portion 1 to start image recording work. . First, the recording operation is performed by the recording unit 1 scanning in a direction orthogonal to the transport direction (502). Thereafter, the end of image recording (503) is determined . If the image recording has been completed (YES in 503), it is determined that the trailing edge of the recording sheet P has already passed through the nip portion of the conveying roller, and the process is terminated. On the other hand, if the image recording has not been completed (NO in 503), the determination of nip removal at the rear end (504) is performed. Here, it is determined whether or not the trailing edge of the recording sheet P passes through the nip portion of the conveying roller 3 and the pinch roller 5 in the next paper feeding operation depending on whether or not the trailing edge of the recording sheet P is detected by the edge sensor. Is done. When the trailing edge of the recording sheet P is not detected by the edge sensor (NO in 504), the rear end of the recording sheet P in the next paper feed operation is INO reaches Shinano the nip portion of the conveying roller, the conveying roller 3 is performed (505). Image recording operation, the recording operation by the recording unit 1 (503), Ru is performed by repeating a conveying roller 3 (or the conveying roller 3 and the paper discharge roller 4) paper transporting operation by (505). The rear end of the record sheet P is thus detected in the edge sensor, at the trailing edge of the recording sheet P at the next paper feed operation is detected that leaves the nip of the conveying roller 3 and the pinch roller 5 (504 YES ), move to pressure release operation.

  In the pressure release operation, as shown in FIGS. 7A to 7B, the paper feeding operation after the recording operation is temporarily stopped (conveyance stopped state), and the spur holder lift gear 94 is moved by a drive unit (not shown). The spur 6 is rotated away from the paper discharge roller 4 (506). That is, the pressing force is temporarily released. By performing this operation, the force acting between the two rollers via the recording sheet P is released, and the deflection of each roller is released. At this time, since the recording sheet P is nipped by the conveying roller 3 and the pinch roller 5, when the deflection of the discharge roller 4 is released, the recording sheet does not move so much that it greatly affects the conveying accuracy. Absent. At this time, the deflection of the conveying roller 3 is also released, but since the amount of deflection is smaller than that of the paper discharge roller 4, the recording sheet does not move to the extent that it greatly affects the conveying accuracy.

  When the release of the deflection is completed, as shown in FIGS. 7B to 7C, the drive unit rotates the spur holder lift gear 94 so that the spur 6 is again brought into pressure contact with the discharge roller 4 (507). ). After the press contact of the spur 6 is completed, the normal paper feeding operation is resumed (505), and the rear end of the recording sheet P is passed through the nip portion between the conveying roller 3 and the pinch roller 5. After the trailing edge of the recording sheet passes through the nip portion between the conveying roller 3 and the pinch roller 5, the paper feeding operation is performed by the paper discharge roller 4 and image recording is performed up to the end of the recording sheet (503).

  In this embodiment, since the setting is made so that the deflection of the paper discharge roller 4 is increased, the spur 6 is separated, but the setting is made so that the deflection of the conveying roller 3 is increased and the pinch roller 5 is separated. good.

  In this embodiment, the pressure contact force is changed as a pressure contact force change mechanism that can change the pressure contact force. However, as an implementation method, a method of decreasing the pressure contact force may be used. In this case, the deflection of the roller can be released up to the reduced holding force (static friction force) of the roller, which cannot be reduced to zero.

  Further, in the present embodiment, the timing of releasing the pressing force is set immediately before the trailing edge of the recording sheet P passes through the nip portion by the next paper feeding operation. However, if the deflection that occurs before the end portion passes through the nip portion can be sufficiently ignored, the pressure contact force is released at a timing before immediately before the trailing edge of the recording sheet P passes the nip portion by the next paper feeding operation. May be. Even during the recording sheet conveyance, for example, immediately before the paper feeding operation is stopped, the change in the conveyance amount due to the roller due to the release of the pressure contact force (the pressure contact in the biaxial conveyance as described in the previous deflection generation mechanism). Since the speed of the recording sheet changes due to the force), the pressure contact releasing operation may be performed during the paper feeding operation. In this way, throughput can be improved.

  According to the present embodiment, the deflection of the roller when the recording sheet is conveyed by the two conveying rollers is reduced before the trailing end of the recording sheet is removed from the nip portion of the conveying roller, thereby Even when the rear end passes through the nip portion, accurate conveyance can be achieved.

(Second Embodiment)
In the present embodiment, a pressing force release mechanism is also provided for the pinch roller 5 on the side having higher rigidity than the first embodiment, and at the same time as the deflection is released, the trailing edge of the recording paper is dealt with by kicking.

  FIG. 8 is a perspective view showing a pressing force releasing mechanism portion in the second embodiment of the present invention. FIG. 9 is a cross-sectional view showing a press-contact / pressure-release state of the press-contact force releasing mechanism in the second embodiment of the present invention. 8 and 9, the same reference numerals are used for the same components as in the first embodiment. Here, the pressure contact force release mechanism (first pressure contact force change mechanism) for the spur 6 is the same as that of the first embodiment, and only the pressure contact force release mechanism (second pressure contact force change mechanism) for the pinch roller 5 will be described. .

  A pinch roller 5 that is driven by the transport roller 3 is rotatably supported by a pinch roller holder 7. The pinch roller holder 7 is rotatably supported on a base (not shown) of the recording apparatus as shown in FIG. 9A, and the pinch roller 5 is pressed against the conveying roller 3 by a pinch roller spring 8. It is energized. A pinch roller holder cam portion 71 is formed on the pinch roller holder 7. A pinch roller holder lift cam 72 having an eccentric cam shape is provided at a portion facing the pinch roller holder cam portion 71. The pinch roller holder lift cam 72 is fixed to the pinch roller holder lift cam shaft 73. Similarly, a pinch roller holder lift gear (not shown) is fixed to the pinch roller holder lift cam shaft 73.

  The pinch roller holder lift cam 72 is configured not to contact the pinch roller holder cam portion 71 as shown in FIG. 9A in a normal state. When a drive unit (not shown) rotates a pinch roller holder lift gear (not shown), the pinch roller holder lift cam 72 rotates and comes into contact with the pinch roller holder cam unit 71, and the pinch roller holder 7 is moved to FIG. 9 (b). Turn to the position shown in. Accordingly, the pinch roller 5 can be separated from the conveying roller 3. By adopting such a configuration, the pinch roller 5 can be separated from the conveyance roller 3 while ensuring the positional accuracy between the pinch roller 5 and the conveyance roller 3 during normal conveyance.

  Next, a control flow during recording will be described. FIG. 10 is a control operation flowchart in the second embodiment of the present invention. FIG. 11 is a diagram showing the state of the transport mechanism element in each control operation state according to the second embodiment of the present invention. Since the operation other than the operation when the trailing edge of the recording sheet passes through the nip portion is the same as that of the first embodiment, the description thereof will be omitted and only the operation of releasing the pressing force will be described.

  In the pressing force releasing operation, as shown in FIGS. 11A and 11B, the paper feeding operation after the recording operation is temporarily stopped, and the spur holder lift gear 94 is driven by a drive unit (not shown) as in the first embodiment. And the spur 6 is separated from the paper discharge roller 4 (506). By performing this operation, the force acting between the two rollers via the recording sheet P is released, and the deflection of each roller is released. At this time, since the recording sheet P is nipped by the conveying roller 3 and the pinch roller 5, the recording sheet P does not move to the extent that it greatly affects the conveying accuracy when the deflection of the discharge roller 4 is released. At this time, the deflection of the conveying roller 3 is also released, but since the amount of deflection is smaller than that of the paper discharge roller 4, the recording sheet does not move to the extent that it greatly affects the conveying accuracy.

  When the release of the deflection is completed, as shown in FIGS. 11 (b) and 11 (c), the driving unit rotates the spur holder lift gear 94 so that the spur 6 is again brought into pressure contact with the discharge roller 4 (507). . After the spur pressure welding is finished, the pinch roller holder lift gear is rotated by a drive unit (not shown), and the pinch roller 5 is separated from the conveying roller 3 as shown in FIGS. 11C to 11D (508). When the separation of the pinch roller 5 is completed, the routine proceeds to a normal paper feeding operation in the state shown in FIG. At this time, since the nip by the conveying roller 3 is released, it is possible to suppress kicking of the trailing edge of the recording sheet when the trailing edge of the recording sheet passes through the nip portion. When the trailing edge of the recording sheet passes through the nip portion, the recording operation by the recording section 1 and the paper feeding operation by the paper discharge roller 4 are repeatedly performed, image recording is performed up to the trailing edge of the recording sheet, and the image recording is completed.

In this embodiment, the roller deflection that occurs when the recording sheet is conveyed by two conveying rollers is released before the trailing edge of the recording sheet passes through the nip portion, and the trailing edge of the recording sheet is the nip portion. releasing the pressure contact force of the rear end side of the roller of the record sheet before leaving the. Thereby, both the influence of the deflection of the roller and the influence of the kicking of the rear end can be suppressed.

  In the first and second embodiments, the case where the pinch roller and the spur are moved to release the pressing force has been described, but the present invention is not limited to this. For example, it is possible to release or reduce the pressure contact force by moving the conveying roller side.

  In the above embodiment, the case where the conveyance roller is bent so as to protrude toward the downstream side in the conveyance direction has been described. However, the present invention is not limited to this, and the conveyance roller is bent so as to protrude toward the upstream side in the conveyance direction. In this case, the present invention can be applied.

  In the above embodiment, the case where the sheet conveying apparatus is applied to the recording apparatus has been described. However, the present invention can be applied to an object other than the recording apparatus that needs to convey the sheet with high accuracy.

P Recording sheet 1 Recording section 3 Conveying roller 4 Discharge roller 5 Pinch roller 6 Spur 7 Pinch roller holder 8 Pinch roller spring 9 Spur holder 10 Spur spring 91 Spur holder cam section 92 Spur holder lift cam 93 Spur holder lift shaft 94 Spur holder lift gear

Claims (5)

A recording unit for recording an image on a sheet;
A first conveying roller that is arranged upstream of the recording unit in the sheet conveying direction and intermittently conveys the sheet by repeating conveying and stopping the sheet ;
Is pressed against the first conveying roller, a first driven roller which rotates following the first conveying roller,
A second conveying roller disposed downstream of the recording unit in the conveying direction and conveying a sheet ;
Is pressed against the second transport roller, and a second driven roller which rotates following the second conveying roller,
A first operation of pressing the second driven roller again after releasing the pressing of the second driven roller in a state where the sheet is intermittently conveyed by the first conveying roller and the second conveying roller. And a control means for executing a second operation for releasing the pressing of the first driven roller after the first operation,
When it is determined that the trailing edge of the sheet passes through the nipping portion between the first transport roller and the first driven roller by the next transport operation, the control unit executes the next transport operation. The recording apparatus, wherein the first operation and the second operation are executed in a state where the previous sheet is stopped, and the next conveying operation is executed after the second operation is completed. . A first press release mechanism that performs the second operation by moving the first driven roller upward ;
The recording apparatus according to claim 1, characterized in that it comprises a second pressure release mechanism to perform the first operation by moving the second driven roller in the vertical direction. An edge sensor arranged upstream of the first transport roller in the transport direction and capable of detecting the trailing edge of the sheet;
2. The control unit according to claim 1, wherein the control unit determines whether or not the trailing edge of the sheet exits the clamping portion by a next transport operation when the edge sensor detects the trailing edge of the sheet. 2. The recording apparatus according to 2. The recording apparatus according to claim 1, wherein the rigidity of the second transport roller is lower than the rigidity of the first transport roller. The recording apparatus according to claim 1 , wherein a conveyance speed of the second conveyance roller is smaller than a conveyance speed of the first conveyance roller.

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