JP6890954B2 - Sheet transfer device and image forming device - Google Patents

Description

The present invention relates to a sheet transporting device for transporting sheets and an image forming apparatus including the same.

In general, an image forming apparatus such as a printer has a sheet separating portion that separates and conveys sheets fed from a feeding cassette one by one by a nip portion formed by pressure contact between a feed roller and a retard roller. The ones that have been prepared are known. For example, when two sheets are overlapped and fed to the nip portion, the feed roller in which the rotational drive is input in the rotational direction for transporting the sheets along the sheet feeding direction feeds the two sheets. The sheet that comes into contact with the rollers is conveyed in the sheet feeding direction. On the other hand, the sheet in contact with the retard roller is sent back to the feeding cassette by the retard roller in which the rotational drive is input in the direction opposite to the rotation direction in which the sheet is conveyed in the sheet feeding direction.

Conventionally, a sheet feeding device has been proposed in which a retard roller is brought into contact with and separated from a feed roller according to an operation of mounting and pulling out a feeding cassette on a main body of the device (see Patent Document 1). In this sheet feeding device, the retard roller is separated from the feed roller when the feeding cassette is pulled out from the main body of the device. This makes it possible to prevent the sheet from being pulled and damaged when the feed cassette is pulled out from the main body of the apparatus while the sheet is sandwiched between the retard roller and the feed roller.

Japanese Unexamined Patent Publication No. 7-206183

By the way, in order to reliably guide the sheet to the nip portion formed by the retard roller and the feed roller, a sheet feeding device in which a guide portion is provided upstream of the nip portion in the sheet transport direction is known. In the sheet feeding device having such a guide portion, the guide portion is maintained at a position close to the feed roller even if the retard roller is separated from the feed roller in response to the pulling operation of the feed cassette. Therefore, the sheet pulled out together with the feed cassette may be caught between the guide portion and the feed roller and damaged.

Therefore, the present invention is a sheet transport device capable of preventing the sheet from being damaged when the sheet support portion is pulled out from the main body of the device while preventing a decrease in the accuracy of guiding the sheet to the nip portion, and an image forming device provided with the same. The purpose is to propose a device.

INDUSTRIAL APPLICABILITY In the sheet transport device, the present invention is provided on the main body of the device so as to be mounted and pulled out, and a seat support portion for supporting the sheet, a rotatable roller, and a separating member which is brought into contact with the roller so as to be detachable. If has, in the roller and the separation member and abuts the nip portion, and a sheet separating unit for conveying while separating the sheets one by one, the sheets sheet fed from the support portion and contactable a guide surface has a support with respect to the a first position where the guide surface to guide the sheet to the nip portion, wherein the apparatus main body movably and a second position away from the roller than the first position, the It has a guided guide portion and a pressed surface that is pressed against the seat support portion during a mounting operation in which the seat support portion is mounted on the apparatus main body, and the separating member can be brought into contact with and detached from the roller. A support portion that can be brought into contact with and detached from the guide portion, and the support portion are attached in a direction in which the pressed surface approaches the seat support portion while the seat support portion is mounted on the apparatus main body. includes a biasing portion for energizing the said support portion, said during a withdrawal operation of the sheet supporting portion is pulled out from the apparatus main body, before the separating member co is moved in a direction away from said roller the serial guide portion so that moving toward the second position from the first position, moved by the biasing force of the biasing unit, the time of the mounting operation of the front Symbol seat support, the separating member to move toward the first position from the second position the front Symbol guide portion co is moved in a direction to abut on the roller, it said that the pressed surface is pressed against the seat support The guide portion moves against the urging force of the urging portion, and the guide portion is separated from the support portion in a state where the seat support portion is attached to the apparatus main body .

According to the present invention, it is possible to prevent the seat from being damaged when the seat support portion is pulled out from the main body of the apparatus while preventing the accuracy of guiding the seat to the nip portion formed in the seat separation portion from being lowered.

The schematic diagram which shows the structure of the printer which concerns on this embodiment. (A) is a cross-sectional view showing a sheet feeding device in a state where the feeding cassette is mounted on the device main body. (B) is a cross-sectional view showing a part of a feeding unit provided in the seat feeding device. (A) is a perspective view showing a feeding unit in a state where the feeding cassette is mounted on the apparatus main body. (B) is a perspective view showing a feeding unit viewed from another direction. (A) is a cross-sectional view showing a sheet feeding device in a state where the feeding cassette is pulled out from the main body of the device. (B) is a cross-sectional view showing a part of the feeding unit. The perspective view which shows the feeding unit in the state which the feeding cassette is pulled out from the apparatus main body. (A) is a cross-sectional view showing a sheet feeding device in a state where a feeding cassette is mounted on a main body of the sheet feeding device according to a modification of the present disclosure. (B) is a cross-sectional view showing a feeding unit in a state where the feeding cassette is pulled out from the apparatus main body.

Hereinafter, the image forming apparatus according to the present embodiment will be described with reference to the drawings. The image forming apparatus according to the present embodiment is an image forming apparatus provided with a fixing device capable of fixing a toner image formed on a sheet to the sheet by heating and pressurizing, such as a copier, a printer, a facsimile, and a composite device thereof. is there. In the following embodiment, as an example of the image forming apparatus, as shown in FIG. 1, a color including an electrophotographic image forming unit 3 and a sheet feeding device 50 for feeding a sheet to the image forming unit 3. A printer 1 which is a laser beam printer will be described. The printer 1 forms an image on a sheet based on, for example, image information input from an external device. However, the sheet refers to a thin layer recording medium such as paper such as paper or an envelope, plastic film (OHT) for an overhead projector, and cloth.

[Outline configuration of printer]
The image forming unit 3 includes a process cartridge 6 including a photosensitive drum 4 which is a photoconductor, and a laser scanner 5 for exposing the photosensitive drum 4. When the image forming unit 3 performs an image forming operation, first, a charger (not shown) uniformly charges the surface of the photosensitive drum 4, and then the laser scanner 5 irradiates the drum surface with laser light according to the image information. This forms an electrostatic latent image. Then, a developer (not shown) supplies toner to the photosensitive drum 4, so that the electrostatic latent image is visualized (developed) as a toner image. The toner image developed on the photosensitive drum 4 is transferred to the sheet at the transfer portion formed by the transfer roller 12 facing the photosensitive drum 4.

Further, the sheet feeding device 50 as a sheet transporting device includes a feeding cassette 60 as a seat supporting portion for supporting the seat, and a feeding unit 70 for feeding the sheet. Feeding unit 70 of this embodiment includes a pickup roller 82 as the feeding roller, a sheet separating unit 55 having a retard roller 102 as a feed roller 81 and the separating member as a roller, a. The pickup roller 82 feeds the sheet stored in the feed cassette 60 to the feed roller 81. Further, the feed roller 81 conveys the sheet received from the pickup roller 82 toward the registration roller pair (hereinafter referred to as the registration roller pair) 11. The retard roller 102, which is pressed against the feed roller 81, is input with a rotational drive in a direction opposite to the rotation direction in which the sheet is conveyed in the sheet feeding direction in which the sheet is fed, and is conveyed one by one by the feed roller 81. Separate the sheets so that.

The resist roller pair 11 abuts on the tip of the sheet in the sheet feeding direction to correct skewing, and conveys the sheet toward the transfer roller 12 as the image forming operation by the image forming unit 3 progresses. The sheet on which the toner image is transferred by the transfer roller 12 is conveyed to the fixing device 13. The fuser 13 has a roller pair that sandwiches and conveys the sheet and a heat source (not shown), and heats and pressurizes the sheet to fix the toner image on the sheet. The sheet that has passed through the fuser 13 is discharged to the discharge tray 15 provided on the upper portion of the apparatus main body 2 by the discharge roller pair 14 via the discharge passage R.

Further, the printer 1 is provided with a control unit 200 that controls each device of the printer 1. The control unit 200 includes a CPU 201 and a memory 202 which is a storage means for storing data. The memory 202 has a ROM 202a for storing a program for controlling each unit and a RAM 202b for temporarily storing data.

[Detailed configuration of sheet feeder]
Next, the detailed configuration of the sheet feeding device 50 will be described with reference to FIGS. 2 and 3. As shown in FIG. 2A, the feeding cassette 60 of the sheet feeding device 50 is detachably attached to the device main body 2 of the printer 1 which also serves as the device main body of the sheet feeding device 50. .. The user can pull out the feeding cassette 60 from the apparatus main body 2 by pulling the feeding cassette 60 in the direction A opposite to the seat feeding direction. The feed cassette 60 has a cassette main body 61 which is a housing for storing the seat, and a lift plate 62 which supports the seat inside the cassette main body 61 and can be raised and lowered by a motor (not shown).

The feed unit 70 is arranged above the feed cassette 60 and includes an upper unit 80 having a pickup roller 82 and a feed roller 81. Further, the feeding unit 70 is arranged downstream of the feeding cassette 60 in the seat feeding direction, and includes a lower unit 100 having a retard roller 102. As shown in FIGS. 2A and 3A, the upper unit 80 has a feed shaft 81a rotatably supported by a bearing 51 fixed to the apparatus main body 2. A feed roller 81 that conveys a sheet fed from the feed cassette 60 is attached to the feed shaft 81a. In this way, the feed roller 81 is positioned with respect to the device main body 2 via the bearing 51.

Further, a seat feeding unit 85 capable of feeding the seat loaded on the lift plate 62 is rotatably supported on the feed shaft 81a. The seat feeding portion 85 includes a feeding roller holder 86 and an arm 90 as roller supporting portions rotatably supported by the feed shaft 81a, and a pickup roller 82. The feed roller holder 86 is rotatably supported by the feed shaft 81a so as to cover the feed roller 81 in the width direction orthogonal to the sheet feed direction and above. As shown in FIGS. 2A and 3B, the feeding roller holder 86 has a pickup shaft 82a on which the pickup roller 82 is rotatably supported, which is rotatably supported in parallel with the feed shaft 81a. Has been done. A pickup roller 82 that comes into contact with a seat placed on the lift plate 62 is attached to the pickup shaft 82a. In this way, the pickup roller 82 is supported by the apparatus main body 2 so as to be able to swing up and down about the feed shaft 81a by rotating the feeding roller holder 86. The pickup roller 82 is also covered by the feeding roller holder 86 in the upper direction and the width direction.

As shown in FIG. 2A, the feed roller holder 86 supports a plurality of (five in this embodiment) feed roller gears 83 connected to the feed shaft 81a and the pickup shaft 82a. A motor M1 (see FIG. 3A) is connected to the feed shaft 81a, and the driving force of the motor M1 input to the feed shaft 81a is transmitted to the pickup shaft 82a via the feed roller gear 83. .. As a result, the feed roller 81 and the pickup roller 82 are driven by the driving force of the motor M1.

As shown in FIGS. 3A and 3B, the arm 90 is arranged on one side in the width direction with respect to the feed roller holder 86 and is rotatably supported by the feed shaft 81a. Further, the arm 90 is connected to the feeding roller holder 86. In the present embodiment, the direction from one to the other in the width direction is the front direction, and the direction from the other to the other is the depth direction. For example, the feeding roller holder 86 is located in the depth direction with respect to the arm 90.

The arm 90 has an extending portion 91 extending in the depth direction, and the extending portion 91 is connected to a clip-shaped connecting portion 87 provided on the upper portion of the feeding roller holder 86. Further, the arm 90 has a lifting portion 92 extending in the front direction. The lifting portion 92 is arranged upstream of the feed shaft 81a in the seat feeding direction, and is configured to be able to come into contact with the arm lever 160 of the lower unit 100, which will be described later.

An arm spring 95 for urging the arm 90 downward is provided on the upper part of the arm 90. As a result, as shown in FIG. 2A, the pickup roller 82 is pressed against the seat placed on the feeding cassette 60 by the urging force of the arm spring 95.

As shown in FIGS. 2 (b) and 3 (a) and 3 (b), the lower unit 100 movably supports the retard roller 102 and the retard roller 102, and hits the upper unit 80 and the feed cassette 60. It has a moving mechanism 101 arranged so as to be in contact with the moving mechanism 101. Moving mechanism 101 includes a separation nip spacing lever 150, the lever arm 160, the retard holder 110. The moving mechanism 101 includes a nip guide release lever 120 as an abutment, and the nip guide portion 130 of the guide member, a.

Of the support portions, the retard holder 110 as a separate support portion is supported by the apparatus main body 2 and rotatably supported by the retard holder shaft 110a arranged downstream of the feed shaft 81a in the sheet feeding direction. In the retard holder 110, a communication hole 111 provided at the upper portion is rotatably inserted into the retard holder shaft 110a, and is arranged in the front direction with respect to the feed roller 81.

As shown in FIG. 3B, a hook portion 112 formed in a hook shape and protruding portions 113 and 114 protruding downward are formed in the lower portion of the retard holder 110. One end of the retard spring 115 as an abutting urging portion is attached to the hook portion 112, and the other end of the retard spring 115 is attached to a frame (not shown) of the apparatus main body 2. The retard holder 110 is urged by the urging force of the retard spring 115 in the direction of arrow B shown in FIG. 2B, that is, in the direction in which the retard roller 102 described later is pressed against the feed roller 81. The protruding portion 113 is arranged in the front direction from the hook portion 112, and the protruding portion 114 is arranged in the depth direction from the hook portion 112.

As shown in FIG. 2B, the retard holder 110 is provided with a retard shaft 102a in which the retard roller 102 is rotatably supported at a position between the communication hole 111 and the hook portion 112 in the vertical direction. There is. The retard shaft 102a is located upstream of the communication hole 111 in the sheet feeding direction, is rotatable by the retard holder 110, and is pivotally supported in parallel with the feed shaft 81a. As shown in FIG. 3A, the retard shaft 102a projects in the depth direction from the retard holder 110 when viewed from the upstream in the sheet feeding direction. A retard roller 102 is attached to a protruding portion thereof, which is located below the feed roller 81.

A torque limiter 102c that transmits torque of a predetermined size or less is connected to the retard shaft 102a, and a retard gear 102d that transmits the driving force from the motor M2 to the torque limiter 102c is connected to the torque limiter 102c. There is. A rotational drive in a direction opposite to the rotational direction in which the seat is fed in the seat feeding direction by the motor M2 is input to the retard shaft 102a via the retard gear 102d and the torque limiter 102c.

Here, as described above, the retard holder 110 is urged by the retard spring 115 so that the retard roller 102 is pressed against the feed roller 81. As a result, as shown in FIG. 2B, the retard roller 102 is formed with a nip portion N between the retard roller 102 and the feed roller 81 which is in pressure contact with the retard roller 102. Further, the retard roller 102 is configured to be able to be brought into contact with and detached from the feed roller 81 by rotating the retard holder 110.

Further, on the retard holder shaft 110a, along with the retard holder 110, a nip guide release lever 120 that can come into contact with the retard holder 110 is rotatably supported. The nip guide release lever 120 is fixed to a strut portion 121 rotatably connected to the retard holder shaft 110a and extends downward and a lower end of the strut portion 121, and is fixed in the width direction downstream of the retard holder 110 in the sheet feeding direction. It has a downstream portion 122 that spreads out.

As shown in FIGS. 2B and 3B, the downstream portion 122 partially overlaps the retard holder 110 when viewed from the upstream in the sheet feeding direction, and the protruding portion 114 of the retard holder 110 is indicated by an arrow. It is arranged at a position where it comes into contact when it swings in the direction opposite to the B direction. Further, the downstream portion 122 protrudes in the depth direction from the retard holder 110 when viewed from the upstream in the seat feeding direction, and a side portion 123 extending toward the upstream in the seat feeding direction is fixed to the protruding end portion. ing. A cylindrical pressing portion 124 extending in the depth direction is fixed to the upstream end of the side portion 123 in the sheet feeding direction.

Further, the nip guide portion 130 is rotatably supported by the device main body 2 and is arranged so as to cover the retard roller 102 in the upstream direction and the width direction in the sheet feeding direction. The nip guide portion 130 has side portions 131a and 131b that cover both sides of the retard roller 102 in the width direction and are rotatably supported by the apparatus main body 2. The side portion 131a is arranged in the depth direction with respect to the retard roller 102, and the side portion 131b is arranged in the front direction with respect to the retard roller 102. A communication hole 133 that communicates in the width direction is formed in the side portions 131a and 131b, a shaft (not shown) fixed to the device main body 2 is inserted into the communication hole 133, and the nip guide portion 130 has a communication hole 133. It is supported by the device main body 2 so as to be rotatable around the device. Further, the side portion 131b is arranged so as to be in contact with the pressing portion 124 of the nip guide release lever 120 at the upper portion located upstream in the sheet feeding direction from the communication hole 133.

A guide surface 132 that covers the upstream of the retard roller 102 in the sheet feeding direction is provided between the side portions 131a and 131b in the upstream of the sheet feeding direction. The guide surface 132 has a plate shape extending in the width direction, and has an end portion 132a whose end portion in the depth direction when viewed from the upstream in the sheet feeding direction projects outward from the side portion 131a.

Further, the nip guide portion 130 has a spring contact surface 134 fixed to the guide surface 132 and the side portions 131a and 131b in a space surrounded by the guide surface 132 and the side portions 131a and 131b. Below the spring contact surface 134, a nip guide spring 140 is provided as a guide urging portion for urging the spring contact surface 134 upward. As a result, the nip guide portion 130 is urged upward, that is, toward the feed roller 81.

The nip guide portion 130 is urged toward the feed roller 81 by the nip guide spring 140, while the end portion 132a is positioned in contact with the frame constituting the apparatus main body 2. The guide surface 132 is a contact surface configured so as to be able to contact the surface on which the retard roller 102 of the sheet fed from the feed cassette 60 comes into contact. As a result, the guide surface 132 guides the sheet sent from the upstream in the sheet feeding direction to the nip portion N in a state where the end portion 132a is in contact with the apparatus main body 2. Hereinafter, the position where the nip guide portion 130 is positioned on the apparatus main body by 2 is referred to as the guide position which is the first position.

Further, when the side portion 131b abuts on the pressing portion 124 of the nip guide release lever 120 and is pressed, the nip guide portion 130 rotates downward against the urging force of the nip guide spring 140. It is configured. That is, when the side portion 131b is pressed by the pressing portion 124, the nip guide portion 130 moves to a separation position (see FIG. 4B), which is a second position away from the feed roller 81 from the guide position.

Here, when the retard roller 102 abuts on the feed roller 81 and the nip guide portion 130 is located at the guide position, the pressing portion 124 of the nip guide release lever 120 hits the side portion 131b of the nip guide portion 130 due to its own weight. It is held in contact. Further, the nip guide release lever 120 is separated from the retard holder 110, and in particular, the downstream portion 122 is separated from the protruding portion 114.

Below the retard holder 110, as shown in FIGS. 3A and 3B, the support portion supported with respect to the apparatus main body 2 is pressed so as to be rotatable around an axis extending in the vertical direction. A separation nip separation lever 150 as a support portion is arranged. The separation nip separation lever 150 is pivotally supported by inserting a shaft (not shown) fixed to the apparatus main body 2 into a communication portion 152 formed so as to communicate in the vertical direction. The separation nip separation lever 150 includes a pressed surface 151 that is pressed against the downstream surface 61a of the feed cassette 60 mounted on the apparatus main body 2, and a holder contact surface 153 that can contact the protruding portion 113 of the retard holder 110. , Have. The separation nip separation lever 150 rotates in a direction opposite to the arrow C direction as the approach direction shown in FIG. 3B when the pressed surface 151 is pressed against the downstream surface 61a of the feed cassette 60.

Further, the separation nip separation lever 150 is configured so that the holder contact surface 153 can be brought into contact with and detached from the protruding portion 113 by rotating. That is, the holder contact surface 153 of the separation nip separation lever 150 is separated from the protrusion 113 by rotating the separation nip separation lever 150 in the direction opposite to the arrow C direction.

Further, as shown in FIG. 3B, an arm lever 160 as a moving member of the urging portion is arranged in the front direction of the retard holder 110. The arm lever 160 is formed in a seesaw shape. The central portion 161 of the arm lever 160 is rotatably supported by a shaft 165 fixed to the apparatus main body 2 in parallel with the feed shaft 81a. The upper end portion 162 of the arm lever 160 is arranged so as to come into contact with the lifting portion 92 of the arm 90 from below. Further, the lower end portion 163, which is the other end opposite to the upper end portion 162 of the arm lever 160, is arranged so as to come into contact with the lever contact surface 154 of the separation nip separation lever 150 from the downstream in the sheet feeding direction.

Further, the shaft 165, the arm lever spring 170 as an urging member is a torsion coil spring is attached. One end of the arm lever spring 170 is fixed to a member constituting the apparatus main body 2, and the other end is fixed to the arm lever 160. The arm lever 160 is fixed in the arrow D direction as the contact direction shown in FIG. 3 (b). To urge. That is, the arrow D direction is the direction in which the lower end portion 163 comes into contact with the lever contact surface 154. Further, the arm lever spring 170 urges the arm lever 160 by a force larger than the urging force of the retard spring 115 and the nip guide spring 140. By this urging force, the arm lever 160 presses the lever contact surface 154 so that the separation nip separation lever 150 rotates in the direction of arrow C.

The separation nip separation lever 150 is pressed in the direction of arrow C by the arm lever 160, but the movement in the direction of arrow C is restricted by abutting on the feed cassette 60 mounted on the apparatus main body 2. Therefore, the arm lever 160 is also restricted from moving in the arrow D direction by the separation nip separation lever 150 whose movement in the arrow C direction is restricted by the feed cassette 60. In this way, the positions of the separation nip separation lever 150 and the arm lever 160 whose movement is restricted by being pressed by the feed cassette 60 mounted on the apparatus main body 2 are set as the regulated positions. The arm lever 160 is separated from the lifting portion 92 of the arm 90 when it is located at the regulated position, and comes into contact with the lifting portion 92 of the arm 90 when it is rotated in the direction of arrow D from the regulated position. Further, when the separation nip separation lever 150 is located at the regulated position, the holder contact surface 153 is separated from the protruding portion 113.

[Operation of feeding unit]
Next, the operation of the feeding unit 70 according to the pulling-out operation and the mounting operation of the feeding cassette 60 will be described. When the user pulls out the feed cassette 60 from the device main body 2, the arm lever 160 is rotated in the arrow D direction from the regulated position by the arm lever spring 170 as shown in FIGS. 4 and 5. As a result, the lower end portion 163 of the arm lever 160 presses the lever contact surface 154 of the separation nip separation lever 150, and the separation nip separation lever 150 rotates in the arrow C direction from the regulated position. Further, the upper end portion 162 of the arm lever 160 abuts on the lifting portion 92 and rotates the arm 90 upward, that is, in the direction of arrow F shown in FIG. As a result, the pickup roller 82 supported by the arm 90 moves upward.

As the separation nip separation lever 150 rotates in the direction of arrow C from the regulated position, the holder contact surface 153 of the separation nip separation lever 150 presses the protruding portion 113. As a result, the retard holder 110 rotates in the direction of arrow E shown in FIG. 4B, and the retard roller 102 supported by the retard holder 110 is separated from the feed roller 81.

As the retard holder 110 rotates in the direction of arrow E, the protruding portion 114 presses the downstream portion 122 of the nip guide release lever 120. As a result, the nip guide release lever 120 also rotates in the direction of arrow E, and the pressing portion 124 of the nip guide release lever 120 presses the nip guide portion 130 downward. When the nip guide portion 130 is pressed by the pressing portion 124, the nip guide portion 130 moves from the guide position to the separated position.

As described above, in the printer 1 of the present embodiment, the retard roller 102 is separated from the feed roller 81 and the nip guide portion 130 is guided to the guide position in conjunction with the pull-out operation in which the feed cassette 60 is pulled out from the apparatus main body 2. Move to a distant position from.

Further, when the user attaches the feed cassette 60 to the apparatus main body 2, the separation nip separation lever 150 presses the pressed surface 151 against the downstream surface 61a of the feed cassette 60 as shown in FIGS. 2 and 3. As a result, it rotates in the direction opposite to the direction of arrow C. As a result, the lever contact surface 154 of the separation nip separation lever 150 presses the lower end portion 163 of the arm lever 160, and the arm lever 160 rotates in the direction opposite to the arrow D direction. The arm lever 160 rotates in the direction opposite to the arrow D direction and moves to the regulated position, so that the upper end portion 162 of the arm lever 160 is separated from the lifting portion 92. As a result, the arm 90 and the pickup roller 82 are pressed against the seat placed on the feed cassette 60 by their own weight and the urging force of the arm spring 95.

The separation nip separation lever 150 rotates in the direction opposite to the arrow C direction to move to the regulated position, so that the holder contact surface 153 is separated from the protruding portion 113. As a result, the retard holder 110 rotates in the arrow B direction due to the urging force of the retard spring 115. When the retard holder 110 rotates in the direction of arrow B, the retard roller 102 supported by the retard holder 110 also rotates in the direction of arrow B and presses against the feed roller 81.

When the retard holder 110 rotates in the direction of arrow B, the protruding portion 114 of the retard holder 110 is separated from the nip guide release lever 120, and the nip guide release lever 120 can also rotate in the direction of arrow B. As a result, the nip guide portion 130 moves from the separated position toward the guide position while pressing the nip guide release lever 120 in the direction of arrow B by the urging force of the nip guide spring 140. Then, when the nip guide portion 130 reaches the guide position, it comes into contact with the device main body 2 and is positioned.

As described above, in the printer 1 of the present embodiment, the retard roller 102 is brought into contact with the feed roller 81 and the nip guide portion 130 is separated in conjunction with the mounting operation in which the feed cassette 60 is mounted on the apparatus main body 2. Move from position to guide position.

By operating the feeding unit 70 of the present embodiment as described above, when the user pulls out the feeding cassette 60 from the apparatus main body 2, the feeding unit 70 has the retard roller 102 and the nip guide from the feed roller 81. The part 130 separates. As a result, in the sheet feeding device 50, when the feeding cassette 60 is pulled out from the device main body 2, the sheet is prevented from being caught between the feed roller 81, the retard roller 102 and the nip guide portion 130 and being damaged. can do. Further, when the sheet is jammed in the nip portion N during sheet transportation, the jammed sheet can be easily removed, and the maintainability of the sheet feeding device 50 can be improved.

When the user pulls out the feed cassette 60 from the apparatus main body 2, the pickup roller 82 moves upward. As a result, the space between the feed roller 81, the retard roller 102, and the nip guide portion 130 can be easily visually recognized, the sheet can be easily removed, and the maintainability of the sheet feeding device 50 can be further improved.

Further, when the user attaches the feed cassette 60 to the apparatus main body 2, the retard roller 102 presses against the feed roller 81, and the nip guide portion 130 returns to the guide position. Therefore, the seat feeding device 50 of the present embodiment can improve the operability of the user while preventing a decrease in the accuracy of guiding the seat to the nip portion N formed in the seat separating portion 55.

When the feed cassette 60 is mounted on the apparatus main body 2, the retard holder 110 is separated from the nip guide release lever 120. As a result, it is possible to prevent the vibration of the retard roller 102 generated during sheet transfer from being transmitted to the nip guide portion 130 via the nip guide release lever 120. Then, it is possible to prevent the accuracy of guiding the sheet to the nip portion N by the guide surface 132 from being lowered, and to prevent the occurrence of jam.

Further, when the feeding cassette 60 is attached to the apparatus main body 2, the arm lever 160 is separated from the arm 90. Thereby, it is possible to prevent the vibration of the pickup roller 82 generated at the time of feeding the seat from being transmitted to the nip guide portion 130 via the arm lever 160. Then, it is possible to prevent the accuracy of guiding the sheet to the nip portion N by the guide surface 132 from being lowered, and to prevent the occurrence of jam.

Further, the feed roller 81 is positioned with respect to the device main body 2, and the nip guide portion 130 is positioned with respect to the device main body 2 at the guide position. As a result, the positional accuracy of the nip guide portion 130 with respect to the nip portion N can be improved, the accuracy with which the guide surface 132 guides the sheet to the nip portion N can be prevented from being lowered, and the occurrence of jam can be prevented.

In the seat feeding device 50 of the present embodiment, the nip guide release lever 120 is supported by the retard holder shaft 110a together with the retard holder 110, but the present invention is not limited to this. As shown in FIG. 6A, the seat feeding device 50 has a nip guide release lever 120A rotatably supported by a shaft arranged at a position closer to the protrusion 114 than the retard holder shaft 110a. It may be configured.

In this case, the nip guide release lever 120A has a shorter distance from the communication hole 121A connected to the shaft to the portion that comes into contact with the protrusion 114, as compared with the nip guide release lever 120 of the present embodiment. Even if the distance that the protrusion 114 moves is the same, the angle at which the nip guide release lever 120A rotates due to the pressing of the protrusion 114 becomes larger than the angle at which the nip guide release lever 120 of the present embodiment rotates. As a result, as shown in FIG. 6B, the pressing portion 124 rotates at a larger angle, the distance for moving the guide portion 130 downward becomes longer, and the guide portion 130 is further separated from the feed roller 81. Can be done.

Further, in the present embodiment, when the feed cassette 60 is pulled out from the apparatus main body 2, the retard roller 102 moves so as to be separated from the feed roller 81, but the present invention is not limited to this. The feed roller 81 may be configured to move away from the retard roller 102. Further, when a guide portion is provided that abuts on the surface of the fed sheet that abuts on the feed roller 81 and guides the nip portion, the guide portion is moved together with the moving feed roller 81. It is preferably configured.

Further, in the present embodiment, the sheet separating portion 55 is configured to have a feed roller 81 and a retard roller 102, but the present invention is not limited to this. Instead of the retard roller 102, the sheet separating portion 55 may be configured to have a separating pad that is urged toward the feed roller 81 and has a friction surface that abuts on the feed roller 81. Further, it is not necessary to input the drive in the direction opposite to the sheet transport direction to the retard roller 102.

Further, in the present embodiment, when the feeding cassette 60 is pulled out from the apparatus main body 2, the retard roller 102 and the nip guide portion 130 are configured to move by a mechanical structure such as a spring. Not limited to. The retard roller 102 and the nip guide portion 130 may be configured to be moved by a power source such as a motor. For example, the printer 1 is provided with a sensor that detects that the feed cassette 60 has been pulled out from the apparatus main body 2. Then, when the sensor detects that the feed cassette 60 has been pulled out from the apparatus main body 2, the retard roller 102 and the nip guide portion 130 may be configured to move by the driving force of the motor.

1: Image forming device (printer) 2: Device main body 3: Image forming unit, 50: Sheet transporting device (sheet feeding device), 55: Sheet separating section, 60: Sheet support device (feeding cassette), 81 : Roller (feed roller), 82: Feeding roller (pickup roller), 85: Seat feeding part, 86: Roller support part (feeding roller holder), 90: Roller support part (arm), 101: Moving mechanism, 102: Separation member (retard roller), 110: Support part (separation support part, retard holder), 115: Contact biasing part (retard spring), 120: Guide part, contact part (nip guide release lever), 130: guide portion, the guide member (nip guide portion), 132: contact surface (guide surface) 140: guide biasing portion (nip guide spring), 150: supporting portion (the pressed support portion, the separation nip spacing lever), 151: pressed surface, 160: biasing portion, the moving member, 170: biasing member (arm lever spring)

Claims (10)

A seat support part that is attached to the main body of the device and can be pulled out to support the seat,
Conveying a rotatable roller, anda separating member which is detachably abut against the roller, at the nip the roller and said separating member is in contact, while separating the sheets one by one Sheet separation part and
Having said sheet sheet fed from the support portion and capable of abutting against the guide surface, a first position in which the guide surface for guiding the sheet to the nip portion, the distance from the roller than said first position A guide unit that is movable to two positions and is supported with respect to the device body,
The seat support portion has a pressed surface that is pressed against the seat support portion during a mounting operation of being mounted on the apparatus main body, and supports the separating member so as to be detachable from the roller and the guide. A support part that can be attached to and detached from the part,
A urging portion for urging the support portion in a direction in which the pressed surface approaches the seat support portion in a state where the seat support portion is mounted on the apparatus main body is provided.
The support portion
During withdrawal operation in which the seat support is pulled out from the apparatus main body, toward the separation member to the second position the front Symbol guide portion from the first position to co is moved in a direction away from said roller in so that moving Te, moved by the biasing force of the biasing unit,
During the mounting operation of the sheet supporting portion, the separation member to move toward the first position before Symbol guide portion from the second position to the co is moved in a direction to abut on said roller When the pressed surface is pressed against the seat support portion, the pressed surface moves against the urging force of the urging portion .
The guide portion is separated from the support portion when the seat support portion is attached to the device main body.
A sheet transfer device characterized by this. By the urging force smaller than urging force by prior Symbol urging unit, in a direction to move to the first position from the second position, further comprising a guide biasing unit that biases the guide portion,
The guide unit
During the pull-out operation, the support portion that moves by the urging force of the urging portion is pressed against the urging force of the guide urging portion to move from the first position to the second position. Move in the direction
When the support portion is separated from the guide portion during the mounting operation, the support portion moves in the direction from the second position to the first position due to the urging force of the guide urging portion.
The sheet transport device according to claim 1. The support portion
A separation support portion that supports the separation member so as to be detachable from the roller,
The has a pressed surface is movable toward and away from the separator support part, said prior SL separating the support portion by the pressing surface moves in the approaching direction to approach the seat support contact, the separating member Has a pressed support portion that moves the separation support portion so as to be separated from the roller.
By the urging force smaller than urging force by prior Symbol urging unit, in a direction to abut said separating member to the roller, further comprising a contact urging unit for urging the separating support,
The urging portion urges the pressed support portion in the approaching direction.
The separation support portion
During the pull-out operation, the separating member is pressed against the pressed support portion that moves in the approaching direction by the urging force of the urging portion, thereby resisting the urging force of the contact urging portion. Move in the direction away from the roller
During the mounting operation, the pressed support portion is pressed by the seat support portion and separated from the separation support portion, so that the separation member is brought into contact with the roller by the urging force of the contact urging portion. Move in the direction of
The sheet transport device according to claim 1 or 2 , wherein the sheet transport device is characterized by the above. The guide portion includes a guide member having a guide surface, an abutment capable abutment to the separation support portion and the guide member, and
The separation support portion
During the drawer operation, it presses the guide member through the abutting portion, Before moving the guide portion in a direction toward said second position from said first position,
The sheet transport device according to claim 3 , wherein the sheet transport device is characterized by this. The contact portion of the guide portion is separated from the separated support portion of the support portion in a state where the seat support portion is attached to the device main body.
The sheet transport device according to claim 4, wherein the sheet transport device is characterized by this. The urging portion includes a moving member that can be brought into contact with and separated from the pressed support portion, and an urging member that urges the moving member in a direction that brings the moving member closer to the pressed support portion.
The pressed support portion is
During the pull-out operation, the moving member is pressed by the urging member to move in the approaching direction.
During the mounting operation, the pressed surface is pressed against the seat support portion, thereby pressing the moving member against the urging force of the urging member.
The sheet transport device according to claim 4 or 5. Further provided with a sheet feeding unit that feeds the sheet in a state of being in contact with the sheet supported by the sheet supporting portion.
The moving member
During the pull-out operation, the seat feeding portion is moved in a direction away from the seat supported by the seat supporting portion.
During the mounting operation, the seat feeding portion is moved in a direction in which the seat feeding portion is brought into contact with the seat supported by the seat supporting portion.
The sheet transport device according to claim 6 , wherein the sheet transport device is characterized by this. The moving member is separated from the seat feeding portion when the seat supporting portion is attached to the device main body.
The sheet transport device according to claim 7. The roller is a feed roller that conveys a sheet.
The separating member is a retard roller that can rotate so that the feed roller conveys the sheet in a direction opposite to the direction in which the sheet is conveyed.
The sheet transport device according to any one of claims 1 to 8 , wherein the sheet transport device is characterized by this. The sheet transport device according to any one of claims 1 to 9,
An image forming unit for forming an image on a sheet conveyed from the sheet conveying device is provided.
An image forming apparatus characterized in that.

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