JP2011148634A - Paper feeder and image forming apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder capable of preventing a malfunction of retreat of a pressing body with space-saving simple constitution with a small number of components without impairing the setting property of a recording medium even in the case of adopting an end fence having the pressing body, and to provide an image forming apparatus. <P>SOLUTION: The end fence 30 provided at a paper feeding cassette 20 includes an end fence body 31; the pressing body 33 mounted to the end fence body 31 turnably between an energizing position to energize the recording medium, and a retreat position to retreat to the end fence body 31 side; a compression spring 34 energizing the pressing body 33 in a paper feeding direction; and a pressing body position switching member 35. When the paper feeding cassette 20 is pulled out of a body case, the pressing body position switching member 35 turns the pressing body 33 into the retreat position against the energizing force of the compression spring 34, and when the paper feeding cassette 20 is inserted, the pressing body position switching member 35 turns the pressing body 33 into the energizing position from the retreat position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a paper feeding device used in an image forming apparatus such as a printer, a copying machine, and a facsimile machine, and more particularly to a paper feeding device employing an end fence having a pressing body.

  In general, as a paper feeding device used in an image forming apparatus, for example, the one shown in FIGS. 5A and 5B is known.

  As shown in FIG. 5A, this type of sheet feeding apparatus includes a cassette main body 101 that stores a sheet-like recording medium S, a bottom plate 103 that is rotatable up and down around a fulcrum portion 102, and a storage. The end fence 104 is slidable in a direction along the paper feeding direction of the recording medium S and can be fixed at an arbitrary position, and the recording medium front end regulating unit 105 that aligns the front ends of the recording medium S in the paper feeding direction. Has been.

  In this sheet feeding device, the bottom plate 103 is urged by an urging means such as a leaf spring (not shown) so that the leading end side in the sheet feeding direction of the stored recording medium S is rotated upward.

  As shown in FIG. 5A, the paper feeding device configured as described above makes the end fence 104 come into contact with the recording medium front end regulating portion 105 after the front end in the paper feeding direction of the recording medium S to be stored is brought into contact with the recording medium front regulating portion 105. The recording medium S is accommodated in the cassette body 101 by being brought into contact with the rear end portion in the paper feeding direction of the recording medium S accommodated by sliding. At this time, the storage position of the recording medium S in the direction along the paper feeding direction is positioned by the recording medium front end regulating portion 105 and the end fence 104.

  In the initial storage state in which a large amount of the recording medium S is stored in the cassette body 101 as described above, the bottom plate 103 is not shown due to the weight of the stored recording paper S as shown in FIG. It rotates so as to be horizontal with respect to the bottom surface of the cassette body 101 against the urging force of the urging means. At this time, the leading end of the recording medium S in the sheet feeding direction is in contact with the recording medium leading end regulating portion 105, and in particular, the uppermost recording medium S is in contact with the outer peripheral surface of the sheet feeding roller 106 so as to be fed. It has become. As a result, this sheet feeding device cooperates with the friction separating pad 120 to rotate the sheet feeding roller 106 to separate and feed the uppermost recording medium S from the other recording media S. Paper can be done.

  By the way, in the above-described paper feeding device, when the feeding of the recording medium S progresses and the recording medium S stored in the cassette body 101 decreases, as shown in FIG. With the decrease, the bottom plate 103 gradually rotates upward about the fulcrum portion 102. With this rotation, the leading end in the sheet feeding direction of the recording medium S stored in the cassette body 101 rises, so that the uppermost recording medium S and the outer peripheral surface of the sheet feeding roller 106 come into contact with each other. Maintained.

  However, in the above-described paper feeding device, since the distance between the recording medium front end restricting portion 105 and the fulcrum portion 102 is not changed, the recording medium S placed on the bottom plate 103 as the bottom plate 103 rotates upward. The leading edge of the sheet feeding direction is gradually separated from the recording medium leading edge regulating portion 105. As a result, as shown in FIG. 5B, the contact between the paper feed roller 106 and the uppermost recording medium S becomes unstable, and a paper feed error is likely to occur.

  Therefore, conventionally, in order to prevent such a paper feeding error, a paper feeding device as shown in FIG. 6 has been proposed.

  As shown in FIG. 6, in this paper feeding device, instead of the end fence 104 described above, the rear end in the paper feeding direction of the recording medium S accommodated in the cassette body 101 is moved forward (recording medium front end regulation). A configuration using an end fence 108 provided with a pressing body 107 that is pressed toward the portion 105 side).

  The pressing body 107 is provided so as to be rotatable so that the pressing surface moves in the direction along the feeding direction of the recording medium S around the fulcrum portion 109, and an urging member such as a spring (not shown). The recording medium S accommodated in the above is always urged toward the recording medium front end regulating portion 105 side. As a result, when the recording medium S stored in the cassette main body 101 is reduced, the recording medium S is pushed out toward the recording medium front end restricting portion 105 by the urging force of the pressing body 107, thereby supplying the paper feeding roller. Stable paper feeding can be performed while maintaining the contact state between the uppermost recording medium S 106 and the uppermost recording medium S constant.

  In the paper feeding apparatus configured as described above, when the recording medium S is not present in the cassette body 101, as shown in FIG. 6A, the pressing body 107 does not have an object to be pressed. Further rotation is restricted by a stopper (not shown) at a position rotated to a state of protruding toward the recording medium front end restricting portion 105 by the urging force of the urging member. When the recording medium S is stored in the cassette body 101 without the recording medium S in the cassette body 101, the bottom plate 103 is moved to the lowest position.

  However, in this paper feeding device, when the recording medium S is stored in the cassette body 101, the pressing body 107 protrudes toward the recording medium front end restricting portion 105, so that the length of the recording medium S is reached. On the other hand, the length in the sheet feeding direction of the set portion of the recording medium S is shortened. For this reason, there is a problem that it is difficult to set the recording medium S while the pressing body 107 is retracted.

  Conventionally, as a paper feeding device that solves such a problem, an end fence main body, a pressing body provided in the end fence main body, and a biasing unit that biases the pressing body forward in the paper feeding direction of the recording medium. And an end fence that includes a biasing force switching unit that switches between a biasing state in which the biasing force of the biasing unit acts on the pressing body and a non-biasing state in which the biasing member does not act is known ( For example, see Patent Document 1).

  In the conventional paper feeding device described in Patent Document 1, when the recording medium is stored in the cassette body, the urging force switching means is switched to the non-biased state so that the end fence body interferes with the recording medium storing operation. After the recording medium is housed in the cassette body in a state where it has been moved to a position that does not become a position, the end fence body is moved to an appropriate position according to the size of the recording medium (hereinafter referred to as a regular set position), and the recording medium In contact with the rear end of the paper feeding direction. As described above, in the conventional paper feeding device, the pressing member does not become an obstacle when the recording medium is stored, and the setting property of the recording medium can be improved.

  In addition, this conventional paper feeding device can be configured to switch between the biased state and the non-biased state by the biasing force switching means in conjunction with the insertion and removal of the cassette body. In this case, when the cassette body is pulled out, the urging force of the urging means is in a non-biased state where it does not act on the pressing body. At this time, the pressing body retreats to a retreat position where it does not protrude forward in the paper feeding direction due to its own weight. As described above, the conventional sheet feeding device can improve the setting property of the recording medium when the recording medium is stored as described above even when the energized state and the non-energized state are automatically switched. .

  However, in the conventional paper feeding device described in Patent Document 1 described above, the end fence body must be moved to a position (backward) that does not interfere with the recording medium storing operation to store the recording medium. Therefore, a space is required for moving the end fence body further to the rear than the normal set position corresponding to the size of the maximum length of the recording medium that can be stored in the cassette body. For this reason, the conventional sheet feeder has a problem that the apparatus itself is enlarged by the amount of space for moving the end fence body as described above.

  In addition, the above-described conventional paper feeding device has a problem that it is difficult to identify the normal setting position of the recording medium by moving the end fence body backward to store the recording medium, thereby increasing the space that can be stored. It was.

  Further, in the above-described conventional paper feeding device, when the recording medium is mistakenly stored in the rear side in the paper feeding direction, the end fence body is moved to the proper set position depending on the weight of the stored recording medium. As a result, the contact between the paper feed roller and the uppermost recording medium becomes unstable, and there is a possibility that a paper feed error may occur.

  Further, in such a conventional paper feeding device, when the urging state by the urging force switching means is automatically switched between the urging state and the non-urging state in conjunction with the insertion and removal of the cassette body, the pressing body is pulled out when the cassette body is pulled out. However, there is a strong concern that the pressing body will not retract due to the sliding resistance of the movable part such as the hinge portion of the pressing body.

  The present invention has been made to solve the above-described conventional problems, and even when an end fence having a pressing body is employed, the setting property of the recording medium is not impaired, and space saving and It is an object of the present invention to provide a sheet feeding device and an image forming apparatus provided with the sheet feeding device that can prevent a malfunction of retracting a pressing body with a simple configuration with a small number of parts.

  In order to achieve the above object, a sheet feeding device according to the present invention has a bottom plate that is rotatable in the vertical direction, and stores a recording medium in a feedable manner, and can be pulled out and inserted into a sheet feeding device body. A paper feeding apparatus comprising: a paper feeding cassette; and an end fence that is provided in the paper feeding cassette and positions a rear end of the recording medium in a paper feeding direction. A pressing body attached to the end fence body so as to be rotatable between an urging position that projects in the paper direction and urges the recording medium and a retreat position that evacuates from the urging position to the end fence body side. A pressing body urging member that urges the pressing body in the paper feeding direction, and a pressing body position switching member that switches between the urging position and the retracted position of the pressing body, Push The body position switching member rotates the pressing body to the retracted position against the urging force of the pressing body urging member when the paper feeding cassette is pulled out with respect to the main body of the paper feeding device. The pressing body is rotated from the retracted position to the urging position when the paper feeding cassette is inserted into the paper feeding device main body.

With this configuration, when the sheet feeding cassette is pulled out from the sheet feeding apparatus body, the sheet feeding device according to the present invention pushes the pressing body position switching member against the urging force of the pressing body urging member. Since the abutting body is rotated to the retracted position, the pressing body is reliably rotated to the retracted position as compared with the conventional case where the pressing body is rotated to the retracted position only by its own weight. It is possible to prevent the malfunction of the retracting of the pressing body.
For this reason, when the recording medium is stored in the paper feeding cassette, the pressing body does not protrude in the paper feeding direction and becomes an obstacle, and the setting property of the recording medium can be improved.

  Further, in the paper feeding device according to the present invention, the pressing body is provided between the one end portion rotatably supported by the end fence body and the urging position and the retracted position with the one end portion as a fulcrum. The pressing body position switching member is rotatably supported by the end fence main body, and the paper feeding device main body according to the drawer of the paper feeding cassette And a cam surface portion that can contact the other end portion of the pressing body, and the contact portion according to the drawer of the sheet feeding cassette. The surface portion rotates by abutting against and being pressed against the fixing member, and the cam surface portion presses the other end portion of the pressing body toward the end fence body side, thereby bringing the other end portion into the retracted position. It has the structure to be rotated.

  With this configuration, in the paper feeding device according to the present invention, the pressing body position switching member rotates as the contact surface portion comes into contact with the fixing member and is pressed in accordance with the drawer of the paper feeding cassette. With the movement, the cam surface portion presses the other end of the pressing body toward the end fence body side so that the other end is rotated to the retracted position. Compared to the conventional configuration for moving to the retracted position, the pressing body can be reliably rotated to the retracted position via the pressing body position switching member with a simple configuration that saves space and has a reduced number of parts. In this way, it is possible to prevent malfunction of retracting the pressing body.

  In the sheet feeding device according to the present invention, the pressing body includes an engaging portion formed at the other end so as to protrude toward the pressing body position switching member, and the pressing body position switching. The member has a holding portion that engages with the engaging portion and holds the pressing body in the retracted position when the paper feeding cassette is pulled out.

  With this configuration, in the paper feeding device according to the present invention, the pressing body has an engaging portion formed at the other end so as to protrude toward the pressing body position switching member, and the pressing body position switching member is The holding unit that holds the pressing body in the retracted position by engaging with the engaging portion when the paper cassette is pulled out has the holding unit in the retracted position when the paper cassette is pulled out. Can be easily and stably held.

  In the paper feeding device according to the present invention, the pressing body position switching member has a lever portion that can come into contact with the fixing member according to the insertion of the paper feeding cassette. Accordingly, when the lever portion abuts against the fixing member and is pressed, the lever portion rotates in a direction opposite to that when the sheet feeding cassette is pulled out, and the engagement between the engagement portion and the holding portion is released. The pressing body rotates to the biasing position.

  With this configuration, in the paper feeding device according to the present invention, the pressing body position switching member has a lever portion that can come into contact with the fixing member according to the insertion of the paper feeding cassette, and according to the insertion of the paper feeding cassette. When the lever part comes into contact with and is pressed against the fixed member, the lever part rotates in the direction opposite to that when the paper feeding cassette is pulled out, the engagement between the engaging part and the holding part is released, and the pressing body is biased. Since it is rotated to the position, when the paper feed cassette is inserted, the pressing body can be reliably rotated from the retracted position to the urging position.

  In the sheet feeding device according to the present invention, the pressing body position switching member biases the pressing body position switching member in a direction in which the pressing body rotates the pressing body from the retracted position to the biasing position. An urging member is provided.

  With this configuration, the paper feeding device according to the present invention is a biasing member that biases the pressing body position switching member in a direction in which the pressing body position switching member rotates the pressing body from the retracted position to the biasing position. Therefore, when the paper feed cassette is inserted, the pressing body can be more reliably rotated from the retracted position to the urging position by the urging force of the urging member.

  In the paper feeding device according to the present invention, the end fence is provided in the paper feeding cassette so as to be movable in a direction along a paper feeding direction of the recording medium.

  With this configuration, in the sheet feeding device according to the present invention, since the end fence is provided in the sheet feeding cassette so as to be movable in the direction along the sheet feeding direction of the recording medium, the recording medium stored in the sheet feeding cassette The trailing end of the recording medium in the sheet feeding direction can be positioned at an optimum position according to the size of the recording medium.

  Furthermore, an image forming apparatus according to the present invention includes the sheet feeding device according to any one of claims 1 to 6.

  With this configuration, the image forming apparatus according to the present invention ensures that the pressing body is in the retracted position as compared with the conventional case where the pressing body is rotated to the retracted position only by its own weight. It can be rotated, and a malfunction of retracting the pressing body can be prevented. Therefore, it is possible to provide an image forming apparatus capable of improving the setability of the recording medium without causing the pressing member to protrude in the sheet feeding direction when the recording medium is stored in the sheet feeding cassette. .

  In the present invention, even when an end fence having a pressing body is adopted, a malfunction of retracting the pressing body can be achieved with a simple configuration that does not impair the setting property of the recording medium and saves space and has a small number of parts. It is possible to provide a sheet feeding device that can be prevented and an image forming apparatus including the same.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. It is a figure which shows a part of sheet feeding apparatus which concerns on embodiment of this invention, Comprising: It is a partially expanded view which shows a sheet feeding apparatus when a pressing body exists in an urging | biasing position. It is a figure which shows a part of sheet feeding apparatus which concerns on embodiment of this invention, Comprising: It is a partially expanded view which shows a sheet feeding apparatus when a pressing body rotates from a biasing position to a retracted position. It is a figure which shows a part of paper feeder which concerns on embodiment of this invention, Comprising: It is a partially expanded view which shows a paper feeder when a pressing body exists in a retracted position. It is the schematic which shows the conventional paper feeder provided with the end fence which does not have a pressing body. It is the schematic which shows the conventional paper feeder provided with the end fence which has a pressing body always urged | biased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the configuration will be described.

  FIG. 1 is a diagram showing an embodiment of an image forming apparatus provided with a sheet feeding device according to the present invention, and shows an example in which the image forming apparatus is applied to an electrophotographic printer (hereinafter simply referred to as a printer). ing. Examples of the above-described printer include a full-color printer that forms an image using a general electrostatic imaging method and a printer that forms a monochrome image.

  As shown in FIG. 1, a printer 1 as an image forming apparatus is provided at the lowermost part in a main body case 1 a, and is stored in a paper feeding unit 2 as a paper feeding device that stores a recording medium S, and stored in the paper feeding unit 2. A sheet feeding roller 3 that separates and feeds the recorded recording media S one by one, an image forming unit 4 that is provided above the sheet feeding unit 2 and forms an image on the recording medium S, and a sheet feeding roller 3. A registration roller pair 5 that is provided in a conveyance path between the image forming unit 4 and the recording medium S fed from the paper feeding unit 2 to feed the recording medium S to the image forming unit 4. The image forming apparatus includes a fixing unit 6 provided above and fixing an image (toner image) formed on the recording medium S.

  The paper feeding unit 2 includes a paper feeding cassette 20 that can be attached to and detached from the main body case 1a as a paper feeding device body, that is, can be pulled out and inserted, and an end fence 30 provided in the paper feeding cassette 20. Has been.

  The paper feed cassette 20 is configured so that the recording medium S can be fed. Further, the end fence 30 is configured to position the rear end of the recording medium S stored in the paper feeding cassette 20 in the paper feeding direction (direction indicated by an arrow in the drawing). Details of the paper feed cassette 20 and the end fence 30 will be described later.

  The image forming unit 4 supplies a photosensitive member 8 on which an electrostatic latent image is written by exposure from the optical writing unit 7, a charging device 9 for uniformly charging the surface of the photosensitive member 8 before exposure, and toner. The developing device 10 that visualizes the electrostatic latent image on the photoconductor 8 as a toner image by the above, the transfer device 11 that transfers the toner image to the recording medium S, and the residual toner on the photoconductor 8 after the transfer is collected And a cleaning device 12 to be configured.

  Further, a paper discharge unit 13 for discharging the recording medium S on which the toner image is fixed in the fixing unit 6 is formed on the upper surface portion of the main body case 1a. Further, a manual feed tray 14 into which the recording medium S can be manually inserted is provided on the side surface of the main body case 1a so as to be freely opened and closed.

  Next, the details of the paper feed cassette 20 and the end fence 30 will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the paper feed cassette 20 includes a cassette main body 21, a bottom plate 22, and a recording medium front end restricting portion 23. When the paper cassette 20 is pulled out from the main body case 1a, the recording is performed. The medium S is stored and replenished.

  The cassette body 21 is configured in a box shape with the top opened, and the recording medium S is accommodated therein.

  The bottom plate 22 is disposed in the cassette body 21 and is configured to be rotatable in the vertical direction around the fulcrum portion 24. Further, the bottom plate 22 is rotated by a push-up type or pull-up type spring (not shown) so that the leading end side in the paper feeding direction of the recording medium S placed on the bottom plate 22 is brought into contact with the outer peripheral surface of the paper feeding roller 3. It is urged upwards to do. Here, when there is no recording medium S on the bottom plate 22, that is, in a state where the recording medium S is not stored in the cassette main body 21, the tip of the bottom plate 22 abuts against the paper feed roller 3, and a spring (not shown). The bottom plate 22 is prevented from rotating by the urging force.

  Further, the bottom plate 22 is locked to a stopper (not shown) provided in the cassette body 21 by pushing down the front end side by a manual operation so as to be in a horizontal state (or a state close to horizontal).

  On the other hand, the bottom plate 22 is automatically released by a stopper releasing means (not shown) provided on the main body case 1a side in the course of an insertion operation in which the paper feed cassette 20 is inserted (attached) into the main body case 1a. Thereby, it rotates upward by the biasing force of the above-mentioned spring. As a result, the leading end side in the sheet feeding direction of the uppermost recording medium S placed on the bottom plate 22 comes into contact with the sheet feeding roller 3.

  Therefore, the recording medium S stored in the paper feed cassette 20 is separated and fed one by one by the cooperative action of the paper feed roller 3 and the frictional separation pad 16 that is in contact with the outer peripheral surface of the paper feed roller 3. Paper.

  The friction separation pad 16 is not limited to being provided in the paper feed cassette 20, but may be provided in the main body case 1a.

  The recording medium front end regulating portion 23 is provided on the front side of the cassette main body 21 in the paper feeding direction, and is arranged to align the front ends of the recording medium S stored in the cassette main body 21 in the paper feeding direction.

  The end fence 30 is provided in the paper feed cassette 20 so as to be movable in the direction along the paper feeding direction of the recording medium S, that is, to be slidable, so that the rear end in the paper feeding direction of the recording medium S is aligned. Yes.

  As shown in FIG. 2, the end fence 30 includes an end fence main body 31, an operation lever 32, a pressing body 33, a compression spring 34 as a pressing body biasing member, and a pressing body position switching member 35. It is comprised including. In addition, in FIG. 1, illustration of the pressing body position switching member 35 is abbreviate | omitted for convenience of explanation.

  The end fence body 31 has a slide projection (not shown) formed on the lower surface thereof, and the slide projection is slidably fitted in a guide groove (not shown) formed on the bottom surface of the cassette body 21. Yes. The guide groove is linearly formed in a direction along the paper feeding direction of the recording medium S accommodated in the cassette body 21.

  Therefore, the end fence main body 31 is movable in the direction along the paper feeding direction of the recording medium S stored in the cassette main body 21 by guiding the above-mentioned sliding convex portion by the guide groove. . As a result, the end fence 30 is movable in the paper feed cassette 20 in the direction along the paper feed direction of the recording medium S.

  Further, the end fence main body 31 has a support shaft 36 fixed to the inner side surface on the rear side in the paper feeding direction among the two inner side surfaces facing in the direction along the paper feeding direction of the recording medium S. One end of the support shaft 36 is fixed to the inner side surface of the end fence body 31, and the other end protrudes toward the pressing body 33. The support shaft 36 may be integrally formed with the end fence main body 31.

  The operation lever 32 is swingably supported at a position facing the pressing body 33 with the end fence body 31 therebetween, and functions as an operation means for fixing the end fence body 31 at an arbitrary position.

  That is, the operation lever 32 has a lower end portion bent in an L shape (located in the front in the paper feeding direction) connected to or integrated with the end fence body 31, and the front end portion is recorded as a fulcrum. The medium S can be rotated in the direction along the paper feeding direction. Further, a claw portion (not shown) is formed on the lower surface of the lower end portion of the operation lever 32. The position of the end fence main body 31 is fixed (locked) by engaging the claw portion with a rack-like tooth portion (not shown) formed on the upper surface of the cassette main body 21. Then, the operation lever 32 can release the meshing between the claw portion and the tooth portion by being pivoted forward in the sheet feeding direction with the tip portion as a fulcrum. Thereby, the lock | rock with the end fence main body 31 and the cassette main body 21 is cancelled | released.

  Therefore, the end fence 30 can move in the direction along the feeding direction of the recording medium S by releasing the lock between the end fence main body 31 and the cassette main body 21 by operating the operation lever 32.

  The pressing body 33 is composed of a plate-like member, and is supported at one end portion 33a rotatably supported on the front side in the sheet feeding direction of the end fence body 31, and the sheet feeding direction with the one end portion 33a as a fulcrum. An urging position (position shown in FIG. 2) for urging the recording medium S that protrudes forward (recording medium front end restricting portion 23 side) and a evacuation position (from the urging position to the end fence body 31 side). And the other end portion 33b that is rotatable with respect to the position shown in FIG.

  That is, the pressing body 33 is accommodated in the cassette body 21 with the support shaft 33c as a fulcrum by fitting the support shaft 33c integrally formed with the one end portion 33a into a mounting hole formed in the end fence body 31. The recording medium S is configured to be rotatable in a direction along the paper feeding direction. Thereby, the pressing body 33 is rotatable between an urging position (position shown in FIG. 2) and a retracted position (position shown in FIG. 4). The support shaft 33c is not limited to being integrally formed with the pressing body 33, and may be configured as an independent shaft member, for example.

  The pressing body 33 has an engaging portion 33d formed at the other end 33b so as to protrude to the front side in the sheet feeding direction, that is, the pressing body position switching member 35 side.

  One end of the compression spring 34 is attached to a support shaft 36 fixed to the end fence body 31. Further, the other end of the compression spring 34 is in contact with or connected to the side surface of the pressing body 33 on the rear side in the paper feeding direction, so that the pressing body 33 is rotated forward in the paper feeding direction of the recording medium S. Energized. By this urging, the pressing member 33 is stopped by a stopper (not shown) in a state where the pressing member 33 protrudes forward from the end fence body 31 in the sheet feeding direction in a state where the recording medium S is not present.

  The pressing body position switching member 35 is rotatably attached to a support portion 31 a provided at a lower portion of the end fence main body 31 on the front side in the sheet feeding direction via a shaft member 38. That is, the pressing body position switching member 35 is rotatable upward and downward with the shaft member 38 as a fulcrum. When the pressing body position switching member 35 is rotated upward, the pressing body 33 is retracted (position shown in FIG. 4). On the other hand, when it is rotated downward, the pressing body 33 is rotated to the urging position (position shown in FIG. 2). Thereby, the urging position and the retracted position of the pressing body 33 are switched.

  The shaft member 38 may be integrally formed with the support portion 31a, or may be integrally formed with the pressing body position switching member 35.

  Further, the pressing body position switching member 35 is provided on the contact surface portion 35 a that can contact the stay 40 provided in the main body case 1 a according to the drawer of the paper feed cassette 20 and the other end portion 33 b of the pressing body 33. The cam surface portion 35b can be contacted, and the lever portion 35c can be contacted to the stay 40 in accordance with the insertion of the sheet feeding cassette 20. The stay 40 according to the present embodiment constitutes a fixing member according to the present invention.

  Further, a tension spring 39 as an urging member is provided between the lever portion 35c and the lower portion of the end fence main body 31 on the front side in the paper feeding direction. The tension spring 39 biases the pressing body position switching member 35 upward, that is, in a direction in which the pressing body position switching member 35 rotates the pressing body 33 from the retracted position to the biasing position. The switching member 35 is biased.

  As shown in FIG. 4, the pressing body position switching member 35 engages with the engaging portion 33 d of the pressing body 33 when the paper feed cassette 20 is pulled out, and retracts the pressing body 33. It has a holding part 35d for holding.

  Next, with reference to FIGS. 2-4, operation | movement of the pressing body position switching member 35 which concerns on this Embodiment is demonstrated.

  As shown in FIG. 2, when the paper feed cassette 20 is inserted (attached) into the main body case 1 a, the pressing body position switching member 35 is moved upward (reversely shown in the figure) by the urging force of the tension spring 39. (Clockwise). The pressing body position switching member 35 is stopped in a state where further rotation is restricted by the lever portion 35c coming into contact with the stopper 31b provided on the end fence main body 31.

  At this time, in the pressing body position switching member 35, the cam surface portion 35 b is not in contact with the other end portion 33 b of the pressing body 33. For this reason, the pressing body 33 is rotated to the urging position by the urging force of the compression spring 34. Here, when the recording medium S is stored in the cassette body 21, the recording medium S in which the pressing body 33 is stored is urged forward in the paper feeding direction (on the recording medium front end restricting portion 23 side). It becomes. In this state, neither the cam surface portion 35 b nor the lever portion 35 c is in contact with the stay 40.

  Next, when the recording medium S in the paper feed cassette 20 runs out, in order to replenish a new recording medium S, the paper feed cassette 20 is pulled out from the main body case 1a in the pulling direction indicated by the arrow in the figure.

  At this time, as shown in FIG. 3, the pressing body position switching member 35 comes into contact with the stay 40 disposed at a position separated forward in the paper feeding direction as the paper feeding cassette 20 moves in the pulling direction. 35a contacts. When the sheet feeding cassette 20 further moves in the pulling direction, the abutting surface portion 35a is pressed against the biasing force of the tension spring 39 in the direction opposite to the pulling direction by the stay 40.

  Thereby, the pressing body position switching member 35 rotates upward, that is, clockwise. Along with this rotation, the cam surface portion 35 b comes into contact with the other end portion 33 b of the pressing body 33 and presses the other end portion 33 b against the end fence body 31 against the urging force of the compression spring 34. By this pressing, the pressing body 33 rotates from the biasing position toward the retracted position.

  Further, when the sheet feeding cassette 20 moves in the pulling direction and the sheet feeding cassette 20 is pulled out to the vicinity of a position where the recording medium S can be stored and replenished, the stay 40 moves the protruding surface portion 35e formed on the contact surface portion 35a. The cam surface part 35b comes to be positioned above the other end part 33b of the pressing body 33.

  At this time, as shown in FIG. 4, the engaging portion 33 d of the pressing body 33 biased by the compression spring 34 is engaged with the holding portion 35 d of the pressing body position switching member 35.

  Next, as shown in FIG. 4, when the paper feeding cassette 20 is pulled out to a position where the recording medium S can be stored and replenished, the pressing member position switching member 35 has the holding portion 35d engaged with the engaging portion 33d. As a result, the pressing body 33 is held in the retracted position.

  In this state, a new recording medium S is stored and replenished in the cassette body 21. At this time, since the pressing body 33 is retracted to the retracted position, for example, there is no trouble that the user has to store the recording medium S while pressing the pressing body 33 manually. The recording medium S can be stored and replenished in the cassette body 21.

  On the other hand, when the supply and replenishment of the new recording medium S to the cassette body 21 is completed, the paper feed cassette 20 is inserted (mounted) in the insertion direction indicated by the arrow in the figure toward the body case 1a.

  At this time, as the pressing body position switching member 35 moves in the insertion direction of the paper feed cassette 20, the lever portion 35c comes into contact with the stay 40 located at a position separated in the insertion direction. Then, when the sheet feeding cassette 20 further moves in the insertion direction, the lever portion 35c is pressed by the stay 40 in the direction opposite to the insertion direction.

  As a result, the engagement between the holding portion 35d and the engaging portion 33d is released, and the pressing body position switching member 35 rotates downward, that is, counterclockwise (the direction opposite to that when pulled out).

  Then, when the engagement between the holding portion 35d and the engaging portion 33d is released, the pressing body 33 rotates from the retracted position toward the urging position. Next, as shown in FIG. 1, the pressing body position switching member 35 stops in a state where further rotation is restricted by the lever portion 35c coming into contact with the stopper 31b.

  At this time, since the cam surface portion 35b is not in contact with the other end portion 33b of the pressing body 33, the recording medium S in which the pressing body 33 is accommodated is moved forward in the sheet feeding direction (on the recording medium front end regulating portion 23 side). ). As a result, the paper feed cassette 20 is ready to feed paper.

  As described above, in the present embodiment, the pressing body position switching member 35 is rotated by the contact surface portion 35a contacting and being pressed against the stay 40 in accordance with the drawer of the sheet feeding cassette 20, Along with the rotation, the cam surface portion 35b presses the other end portion 33b of the pressing body 33 toward the end fence body 31 so that the other end portion 33b is rotated to the retracted position (position shown in FIG. 4). Therefore, compared with the conventional configuration in which the pressing body is moved to the retracted position only by the weight of the pressing body, the pushing body is pushed via the pressing body position switching member 35 with a simple configuration with less space and the number of parts. The abutting body 33 can be reliably rotated to the retracted position, and a malfunction of the retracting of the abutting body 33 can be prevented.

  For this reason, when the recording medium S is stored in the paper feed cassette 20, the pressing member 33 does not get in the way of feeding forward in the paper feeding direction, and the setability of the recording medium S can be improved.

  Moreover, in this Embodiment, the pressing body 33 has the engaging part 33d formed in the other end part 33b so that it may protrude to the pressing body position switching member 35 side, and the pressing body position switching member 35 is When the paper cassette 20 is pulled out, it has a holding portion 35d that engages with the engaging portion 33d and holds the pressing member 33 in the retracted position. The pad 33 can be easily and stably held at the retracted position.

  Further, in this embodiment, the pressing body position switching member 35 has a lever portion 35 c that can come into contact with the stay 40 according to the insertion of the paper feed cassette 20, and the lever according to the insertion of the paper feed cassette 20. When the portion 35c contacts and is pressed against the stay 40, the portion 35c rotates in the direction opposite to that when the sheet feeding cassette 20 is pulled out, and the engagement between the engaging portion 33d and the holding portion 35d is released, and the pressing body Since 33 is rotated to the urging position (position shown in FIG. 2), when the paper feed cassette 20 is inserted, the pressing body 33 can be reliably rotated from the retracted position to the urging position. it can.

  In the present embodiment, the pressing body position switching member 35 includes a tension spring 39 that biases the pressing body position switching member 35 in a direction in which the pressing body 33 rotates from the retracted position to the biasing position. Therefore, when the paper feed cassette 20 is inserted, the pressing body 33 can be more reliably rotated from the retracted position to the biased position by the biasing force of the tension spring 39.

  Furthermore, in the present embodiment, the end fence 30 is provided in the paper feed cassette 20 so as to be movable in the direction along the paper feed direction of the recording medium S. Therefore, the recording medium S stored in the paper feed cassette 20 is provided. The rear end of the recording medium S in the paper feeding direction can be positioned at an optimum position according to the size of the recording medium S.

  As described above, the paper feeding device according to the present invention has a simple configuration that does not impair the setting property of the recording medium and saves space and has a small number of parts even when an end fence having a pressing body is employed. Thus, it is possible to prevent malfunction of retracting the pressing body, and it is useful as a sheet feeding device that employs an end fence having the pressing body.

1 Printer (image forming device)
1a Body case (paper feeder body)
2 Paper feeder (paper feeder)
DESCRIPTION OF SYMBOLS 20 Paper feed cassette 22 Bottom plate 30 End fence 31 End fence main body 33 Pressing body 33a One end part 33b Other end part 33d Engaging part 34 Compression spring (pressing body biasing member)
35 Pressing body position switching member 35a Contact surface portion 35b Cam surface portion 35c Lever portion 35d Holding portion 39 Tension spring (biasing member)
40 stay (fixing member)

JP 2004-142892 A

Claims (7)

A sheet feeding cassette that has a bottom plate that is pivotable in the vertical direction, accommodates a recording medium in a feedable manner, and can be pulled out and inserted into a sheet feeding apparatus body; and the recording medium provided in the sheet feeding cassette. An end fence for positioning the rear end of the sheet feeding direction,
The end fence is rotatable between an end fence main body, a biasing position that projects in the paper feeding direction and biases the recording medium, and a retreat position that retreats from the biasing position to the end fence main body side. Switching between a pressing body attached to the end fence body, a pressing body biasing member that biases the pressing body in the paper feeding direction, and the biasing position and the retracted position of the pressing body. A pressing body position switching member,
The pressing body position switching member moves the pressing body to the retracted position against the urging force of the pressing body urging member when the paper feeding cassette is pulled out with respect to the paper feeding device main body. A paper feeding device that rotates and turns the pressing body from the retracted position to the biasing position when the paper feeding cassette is inserted into the paper feeding device main body. The pressing body has one end portion rotatably supported by the end fence body and the other end portion rotatable between the biasing position and the retracted position with the one end portion as a fulcrum. And
The pressing body position switching member is rotatably supported by the end fence main body, and is capable of coming into contact with a fixing member provided in the paper feeding device main body according to the drawer of the paper feeding cassette. A surface portion and a cam surface portion capable of abutting against the other end portion of the pressing body, and the abutting surface portion abuts on and is pressed against the fixing member in accordance with the drawer of the sheet feeding cassette. The cam surface portion rotates the other end portion to the retracted position by pressing the other end portion of the pressing body toward the end fence main body side. The paper feeder described. The pressing body has an engaging portion formed at the other end so as to protrude toward the pressing body position switching member.
The pressing body position switching member includes a holding portion that engages with the engaging portion and holds the pressing body in a retracted position when the sheet feeding cassette is pulled out. The sheet feeding device according to 2. The pressing body position switching member has a lever portion that can come into contact with the fixing member in accordance with insertion of the sheet feeding cassette,
In response to the insertion of the paper feed cassette, the lever portion abuts against the fixing member and is pressed to rotate in a direction opposite to that when the paper feed cassette is pulled out, and the engagement portion and the holding portion The paper feeding device according to claim 3, wherein the engagement is released and the pressing body rotates to the biasing position.   The pressing body position switching member includes a biasing member that biases the pressing body position switching member in a direction to rotate the pressing body from the retracted position to the biasing position. The sheet feeding device according to any one of claims 2 to 4.   The paper feeding device according to claim 1, wherein the end fence is provided in the paper feeding cassette so as to be movable in a direction along a paper feeding direction of the recording medium.   An image forming apparatus comprising the paper feeding device according to claim 1.

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