JP2008207946A - Sheet feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device and an image forming device capable of improving usability. <P>SOLUTION: A slide cassette 4 is locked to a cassette body 4a by a first lock part, a paper feeding cassette is held in a contracted state or in an extended state, and a rear end regulating member 5 is locked in a position corresponding to a size of a stored sheet on the slide cassette. When the rear end regulating member 5 is slid to a contraction direction by a third lock part, the rear end regulating member 5 is locked to the slide cassette 4 so that the slide cassette 4 is integrally slid with the rear end regulating member 5. Locking of the first lock part and the second lock part is released in accordance with operation for sliding the rear end regulating member 5, and locking of the third lock part is released when the slide cassette 4 slid to the contraction direction with the rear end regulating member 5 reaches a prescribed position, and then, only the rear end regulating member 5 is slid to the contraction direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus and an image forming apparatus, and more particularly to a sheet feeding cassette that houses a sheet and a slide cassette provided in a cassette body.

  Conventional image forming apparatuses such as copiers, printers, facsimiles and the like are provided with a sheet feeding device, and a sheet is fed from the sheet feeding device to an image forming unit to form an image. is doing. As such a sheet feeding apparatus, a sheet feeding cassette as a sheet storage unit is detachably attached to the image forming apparatus main body, and the sheet stored in the sheet feeding cassette is attached to the image forming unit by a sheet feeding roller. In general, automatic feeding is performed.

  Here, when a sheet smaller than the maximum size sheet that can be stored is stored in the cassette main body in which the sheets of the sheet feeding cassette are stored, the rear end in the sheet feeding direction of the stored sheet (hereinafter referred to as the rear end). ) Is provided. Further, a side end regulating member that regulates a side end position of a sheet in a direction orthogonal to the sheet feeding direction (hereinafter referred to as a width direction) is provided.

  In such a sheet feeding cassette, the side edge of the sheet is regulated by the side edge regulating member, while the trailing edge is regulated by the trailing edge regulating member so that the leading edge position of the sheet is always regulated to a predetermined position. ing. Thus, when the sheet feeding cassette is stored in the image forming apparatus main body, stable sheet feeding can be performed regardless of the sheet size.

  By the way, in recent years, the image forming apparatus has been downsized in order to improve space efficiency. However, when the image forming apparatus is downsized in this way, the image forming apparatus main body is shorter than the used sheet. There is. In this case, when the paper feed cassette is mounted on the main body of the image forming apparatus, the paper feed cassette protrudes from the main body of the image forming apparatus, resulting in a problem that the space efficiency is poor.

  Therefore, in order to solve such a problem, there is a type in which a slide cassette as a drawer portion is provided in the cassette body of the paper feed cassette, and the slide cassette is pulled out and used according to the sheet size. In such an extendable sheet feeding cassette, when a small size sheet is stored, it is used as it is, and when a large size sheet is stored, the slide cassette is pulled out and used.

  In such a conventional paper feed cassette, the slide cassette is fixed at the pull-out position or the storage position by a lock member. When the slide cassette is pulled out or stored, the lock member is unlocked and the slide cassette is pulled out or stored (see Patent Document 1).

  Here, FIG. 19 is a perspective view of such a conventional telescopic paper feeding cassette. In FIG. 19, reference numeral 102 denotes an extendable paper feed cassette; 103, a cassette body; 104, a slide cassette slidably provided on the cassette body; 106, a lock member; and 105, a rear end regulating member.

  Such a sheet cassette 102 is used by moving the slide cassette 104 to a position where the slide cassette 104 can be contracted, as shown in FIG. When storing a large-sized sheet, the slide cassette 104 is pulled out from the cassette body 103 and used as shown in FIG. When the sheet feeding cassette 102 is expanded and contracted in this way, the lock member 106 that holds the positions of the cassette body 103 and the slide cassette 104 is released.

JP 2004-107909 A

  However, in such a conventional sheet feeding cassette, for example, when a sheet of a different size is stored in the sheet feeding cassette, the slide cassette 104 is pulled out or stored. When such an operation is performed, the sheet to be stored is stored. It is a case where the size of is changed.

  When the sheet size is changed in this way, it is necessary to move the position of the trailing edge regulating member 105 for positioning the trailing edge of the sheet. That is, in the conventional paper feed cassette, the operation of moving the slide cassette and the operation of moving the rear end regulating member are independent of each other. As a result, when changing the sheet size, the user needs to perform two operations, and the usability is not good.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide a sheet feeding apparatus and an image forming apparatus capable of improving usability.

  The present invention relates to a sheet feeding apparatus that feeds sheets stored in a sheet feeding cassette, wherein the sheet feeding cassette includes a cassette body, a slide cassette provided slidably on the cassette body, and the slide cassette. A rear end regulating member that is slidable and regulates a rear end of a sheet stored in the paper feed cassette; a first lock portion that locks the slide cassette to the cassette body; and the rear end regulating member A second lock portion that locks on the slide cassette at a position corresponding to the size of the sheet to be stored, and the rear cassette so that the slide cassette slides integrally with the rear end regulating member when the rear end regulating member slides. A third locking portion that locks the end regulating member and the slide cassette, and allows the rear end regulating member to slide. Thus, the lock of the first lock portion and the second lock portion is released, and the lock of the third lock portion is released when the slide cassette that slides in the sheet feeding direction together with the rear end regulating member reaches a predetermined position. It is characterized by that.

  As in the present invention, the slide operation of the rear end restricting member can release the lock of the slide cassette with respect to the cassette body and the lock of the rear end restricting member with respect to the slide cassette, so that usability can be improved.

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

  FIG. 1 is a diagram showing a schematic configuration of a laser beam printer which is an example of an image forming apparatus provided with a sheet feeding apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer, and 1A denotes a laser beam printer main body (hereinafter referred to as a printer main body). The laser beam printer 1 fixes an image forming unit 1B, a sheet feeding device 1C that feeds the sheet S to the image forming unit 1B, and a toner image transferred onto the sheet S by the transfer unit 1D. A fixing unit 13 and the like are provided.

  Here, the image forming unit 1B includes a process cartridge 6 including a photosensitive drum 6a, a charging roller 6b, a developing sleeve 6c, a cleaning blade 6e, and a toner container 6d in a detachable manner. Also provided is a laser exposure device 7 that exposes the surface of the photosensitive drum 6a to form an electrostatic latent image on the photosensitive drum.

  The charging roller 6b is a charging unit that uniformly charges the surface of the photosensitive drum 6a. The developing sleeve 6c is a toner image formed by attaching toner to the electrostatic latent image formed by the laser exposure device 7. Developing means for forming an image. The cleaning blade 6e removes the toner remaining on the surface of the photosensitive drum 6a after the toner image is transferred, and stores it in a waste toner container 6f.

  The sheet feeding device 1C is provided at the lower part of the printer main body 1A, and feeds the sheet cassette 2 as a sheet storage unit that is detachably attached to the printer main body 1A and the sheet S on the sheet feeding cassette one by one. And a half-moon shaped sheet feeding roller 9. The paper feed cassette 2 is provided with a separation pad 10 which is a separation means. Here, the paper feed cassette 2 is detachably mounted in a mounting space 1E provided at the bottom of the printer main body 1A.

  The transfer unit 1D forms a transfer nip by pressing against the photosensitive drum 6a and the photosensitive drum 6a, and transfers the toner image on the photosensitive drum to the sheet S when the sheet S passes through the transfer nip. The transfer roller 8 is used.

  Next, an image forming operation in the laser beam printer 1 configured as described above will be described.

  When the image forming operation is started, first, the photosensitive drum 6a rotates in the direction of arrow A, and is uniformly charged to a predetermined polarity and a predetermined potential by a charging roller 6b fed from a high voltage power source (not shown). The photosensitive drum 6a whose surface has been charged is irradiated with laser light L emitted from the laser exposure device 7 based on the image information and reflected by the reflecting mirror 7a. An electrostatic latent image is formed.

  Next, the electrostatic latent image is filled in the toner container 6d as the developing sleeve 6c rotates, and the toner that has been appropriately charged is supplied onto the photosensitive drum 6a and adheres to the electrostatic latent image. By doing so, it is developed and visualized as a toner image.

  On the other hand, in parallel with such a toner image forming operation, the sheets S stacked and stored in the sheet feeding cassette 2 are fed from the sheet feeding roller 9 at a predetermined timing. Note that the sheet feeding roller 9 holds a position where it does not contact the separation pad 10 during standby. When the image forming operation is started, the sheet feeding roller 9 rotates once, and the sheet S fed along with this rotation is separated. The sheet is conveyed while being sandwiched between the pad 10 and the sheet feeding roller 9.

  Here, the friction coefficient, contact angle, and shape of the surface of the separation pad 10 that is the sheet separation means are set so as to feed out only the uppermost sheet S for each sheet feeding operation. Thereby, when the sheets S are overlapped and fed, the conveyance of the sheet S on the separation pad side is suppressed by the separation pad 10, and only the sheet S on the feeding roller side is conveyed. As a result, the sheets S stacked and stored in the sheet feeding cassette 2 are conveyed one by one through the conveying roller pair 11a and 12a to the registration roller pair 11b and 12b without being conveyed in an overlapping manner.

  Next, the sheet S conveyed to the registration roller pair 11b and 12b in this way is corrected for skew in the registration roller pair 11b and 12b. Thereafter, the pair of registration rollers 11b and 12b are conveyed to the transfer unit 1D at a timing so that the leading edge of the sheet S coincides with the leading edge of the toner image formed on the surface of the photosensitive drum 6a. Then, the toner image on the surface of the photosensitive drum 6a is transferred by the transfer roller 8 to the sheet S thus conveyed to the transfer unit 1D.

  The untransferred toner remaining on the photosensitive drum 6a without being transferred is stored in the waste toner container 6f by the cleaning blade 6e. The photoreceptor drum 6a whose surface has been cleaned repeatedly enters the next image forming process.

  Next, the sheet S to which the toner image is transferred is conveyed to the fixing unit 13, and the toner image is fixed to the sheet S in the fixing unit 13. Thereafter, the sheet S on which the toner image is fixed is conveyed to the discharge roller pair 14c and 15c by the conveyance roller pair 14a and 15a and the conveyance roller pair 14b and 15b disposed in the sheet conveyance downstream portion of the fixing unit 13. The Thereafter, the paper is discharged onto a paper discharge tray 16 provided on the upper portion of the printer main body 1A by a pair of paper discharge rollers 14c and 15c.

  FIG. 2 is a perspective view of the paper feed cassette 2, and FIG. 3 is an exploded perspective view of the paper feed cassette 2. As shown in FIGS. 2 and 3, the sheet feeding cassette 2 includes a main cassette 3 that constitutes a cassette body that is a sheet storage unit body, and a slide cassette 4 that is slidable (can be pulled out) on the main cassette 3. And.

  Then, depending on the size of the sheet, as shown in FIGS. 13 to 15 described later, by pulling out or storing the slide cassette 4, sheets of different sizes can be stored in the sheet feeding cassette 2. Yes.

  The main cassette 3 is provided with a middle plate 31 that stacks sheets and rotates upward according to the sheet stacking amount to press the sheet S against the sheet feeding roller 9 and assist the sheet feeding operation. The slide cassette 4 is provided with a trailing edge regulating member 5 that regulates the trailing edge position of the sheet stored in the sheet feeding cassette 2 so as to be movable in the sheet feeding direction.

  The middle plate 31 is provided with side regulating members 31R and 31L that regulate the side end positions in the width direction of the sheets stored in the sheet feeding cassette 2. The side regulating members 31R and 31L regulate the side edge of the sheet, while the trailing edge regulating member 5 regulates the trailing edge, so that the sheet can be stably fed regardless of the sheet size. I am doing so.

  FIG. 4 is a perspective view showing a state in which the rear end regulating member 5 is removed from the slide cassette 4 of the paper feed cassette 2, and in FIG. 4, 4b is a first lock member. As shown in FIG. 5, the first lock member 4b rotates in the lateral direction with a rotation shaft 4d provided perpendicular to the slide cassette body 4a as a fulcrum.

  A first lock spring 4c is provided between the first lock member 4b and the slide cassette body 4a, and the first lock spring 4c is in pressure contact with one rotating end of the first lock member 4b. A surface 4f is provided. The other end portion is provided on one side wall surface of a rib 3d that is suspended from the bottom surface of the main cassette body 3a of the main cassette 3 and extends in the sheet feeding direction, and is configured by triangular teeth. A latch portion 4e that meshes with the locked portion 3b is provided.

  The latch portion 4e of the first lock member 4b is configured by triangular teeth, and normally meshes with the locked portion 3b of the main cassette body 3a by the urging force of the first lock spring 4c. Yes.

  And the slide cassette 4 can be locked with respect to the main cassette 3 by meshing | engaging the latch part 4e of the 1st lock member 4b, and the to-be-latched part 3b of the main cassette main body 3a in this way.

  That is, in the present embodiment, the first lock member 4b, the first lock spring 4c, and the locked portion 3b of the main cassette body 3a that meshes with the latch portion 4e of the first lock member 4b are used to lock the first lock member 4b. The part is composed. Then, the slide cassette 4 is locked to the main cassette 3 by the first lock portion so as to hold the paper cassette 2 in a shortened state or an extended state.

  FIG. 6 is a cross-sectional view of a rear end restricting portion mounting portion of the slide cassette 4. As shown in FIG. 6, the rear end restricting member 5 is centered on a rear end restricting lever 5a that is a lever member and a rotating shaft 5b. And a rear end regulating holder 5c for rotatably holding the rear end regulating lever 5a.

  Here, for example, when the slide cassette 4 is pulled out according to the sheet size, that is, when the paper feed cassette 2 is extended, the rear end regulating lever 5a is pressed in the direction of arrow B as shown in FIG.

  Then, when the rear end regulating lever 5a is pressed in this way, the rear end regulating lever 5a is inclined with the rotation shaft 5b shown in FIG. 5 as the center, and the first lock member 4b is applied to the force of the first lock spring 4c at the point BB. I will push against it. In this way, when pushed by the rear end regulating lever 5a, the first lock member 4b is moved in parallel by a guide member (not shown).

  As a result, the latch portion 4e of the first lock member 4b is disengaged from the locked portion 3b of the main cassette body 3a, the lock of the first lock member 4b is released, and the slide cassette 4 can be pulled out. . Thereby, when the rear end regulating lever 5a is further pressed in the arrow B direction, the slide cassette 4 is pulled out.

  After the slide cassette 4 is pulled out in this way, when the pressing of the rear end regulating lever 5a is released, the latch portion 4e and the locked portion 3b of the main cassette body 3a are engaged with each other by the first lock spring 4c, and the main cassette 3, the slide cassette 4 is locked.

  On the other hand, when the slide cassette 4 is stored according to the sheet size, that is, when the paper feed cassette 2 is shortened, the rear end regulating lever 5a is pressed in the direction of arrow C as shown in FIG. Then, when the rear end regulating lever 5a is pressed in this way, the rear end regulating lever 5a is inclined in the direction of the arrow C around the rotation shaft 5b, and the first lock member 4b is made to be the force of the first lock spring 4c at the point CC. Push against.

  As a result, the first lock member 4b rotates about the rotation shaft 4d, the engagement of the latch portion 4e with the locked portion 3b of the main cassette body 3a is released, and the lock of the first lock member 4b is released. This is released, and the slide cassette 4 can be moved in the storage direction. Thereafter, when the rear end regulating lever 5a is further pressed in the arrow C direction in this state, the slide cassette 4 is accommodated in the main cassette as shown in FIG. After that, when the pressing in the arrow C direction is released from the rear end regulating lever 5a, the slide cassette 4 is locked to the main cassette 3 by the first lock spring 4c.

  That is, in the present embodiment, the first lock member 4b moves in the disengagement direction in accordance with the pressing operation in the sliding direction of the rear end regulating member 5 (rear end regulating lever 5a), and the first lock portion The lock is released.

  By the way, when storing sheets of different sizes in the sheet feeding cassette 2, it is necessary to lock the slide cassette 4 after moving the trailing edge regulating member 5 according to the size of the sheet to be stored. Next, a description will be given of a second lock portion that locks the rear end regulating member 5 at a position on the slide cassette according to the size of the sheet to be stored.

  FIG. 9 is a diagram for explaining a second lock portion that locks the rear end regulating member 5 at a position corresponding to the size of the sheet that houses the rear end regulating member 5.

  As shown in FIG. 9, a second lock member 5h and a second lock spring 5f are arranged in the rear end regulating holder 5c. The second lock member 5h is disposed so as to be movable in the vertical direction with respect to the rear end regulating holder 5c, and is formed on the bottom surface of the slide cassette body 4a on the top surface, and has a triangular tooth extending in the sheet feeding direction. It has a latch part 5d which meshes with a locked part 4g constituted by. Further, the upper surface has a receiving surface 5e of the second lock spring 5f.

  The latch portion 5d of the second lock member 5h is configured with triangular teeth and is normally engaged with the locked portion 4g on the slide cassette body 4a by the urging force of the second lock spring 5f. It has become. Then, the rear end regulating lever 5a can be locked to the slide cassette 4 by engaging the latch portion 5d of the second lock member 5h and the engaged portion 4g on the slide cassette body 4a in this way. .

  In other words, in the present embodiment, the second lock portion includes the second lock member 5h, the second lock spring 5f, and the locked portion 4g on the slide cassette body 4a that meshes with the latch portion 5d of the second lock member 5h. It consists of.

  Here, as shown in FIG. 9B, the shape of the teeth of the latch portion 5d of the second lock member 5h and the engaged portion 4g on the slide cassette body 4a is indicated by the arrow B of the second lock member 5h. It has a shape that prohibits movement in the opposite direction (drawing direction) to the sheet feeding direction shown. Further, the shape of the teeth of the latch portion 5d and the locked portion 4g is such that when the second lock member 5h moves in the sheet feeding direction (storage direction) indicated by the arrow C, the second lock member 5h is directed upward. It is shaped so that it can move while being saved.

  That is, the rear end regulating member 5 (the second lock member 5h) is locked to move in the direction of arrow B (drawing direction) due to the shape of the teeth of the latch portion 5d and the locked portion 4g, but the arrow C Movement in the direction (storage direction) is possible.

  By the way, in the 2nd lock part comprised in this way, if the rear-end control lever 5a is pressed in the arrow B direction as shown, for example in FIG. 10, the rear-end control lever 5a will incline in the arrow B direction. Here, the rear end regulating lever 5a is provided with an engaging projection 5t that engages with the second lock member 5h when tilted in this way. Accordingly, when the rear end regulating lever 5a is inclined, the engagement protrusion 5t lifts the second lock member 5h against the force of the second lock spring 5f at the point BBB.

  As a result, the engagement between the latch portion 5d and the locked portion 4g is released, and the lock of the rear end regulating lever 5a with respect to the slide cassette 4 is released. When the rear end regulating lever 5a is unlocked in this way, the rear end regulating lever 5a is then pressed in the direction of the arrow B, so that the rear end regulating member 5 can be adjusted according to the sheet size. You can move to a position.

  Here, when the rear end regulating lever 5a is pressed in the direction of the arrow B in this way, the lock of the first lock member 4b is released as described above. As a result, the slide cassette 4 moves integrally with the rear end regulating member 5 to a position corresponding to the sheet size. When the rear end regulating member 5 reaches the predetermined position and then the pressing in the arrow B direction is released from the rear end regulating lever 5a, the rear end regulating member 5 is locked to the slide cassette 4 by the second lock spring 5f. At the same time, the slide cassette 4 is locked with respect to the main cassette 3.

  By the way, in the present embodiment, when the rear end regulating member 5 is slid in the extending direction in which the slide cassette 4 extends the paper feed cassette 2, the slide cassette 4 slides integrally with the rear end regulating member 5. ing. Further, when the slide cassette 4 is slid in the shortening direction for shortening the paper feed cassette 2, the slide cassette 4 slides integrally with the rear end regulating member 5 to a predetermined position.

  Next, a description will be given of a third lock portion that locks the rear end regulating member 5 to the slide cassette 4 so as to interlock with the expansion and contraction operation of the slide cassette 4 as described above. 11A and 11B are perspective views for explaining the configuration of the third lock portion that locks the rear end regulating member 5 to the slide cassette 4. FIG. 12A is a sectional view taken along the line DD in FIG. It is -E sectional drawing.

  The rear end regulating holder 5c is provided with a third lock member 5j that is pivotable about the pivot shaft 5m with respect to the rear end regulating holder 5c, and a third lock member 5j that biases the third lock member 5j downward. 3 A lock spring 5k and a contact portion 5p are provided.

  The third lock member 5j is normally configured to be engaged with a locked portion 4h protruding from the slide cassette body 4a by the urging force of the third lock spring 5k. When the rear end regulating member 5 is pressed in the direction of the arrow C by engaging the third lock member 5j with the locked portion 4h on the slide cassette body 4a in this way, the rear end regulating member 5 is The slide cassette 4 is locked.

  That is, in the present embodiment, the third lock portion is a locked portion protruding from the slide cassette body 4a that engages with the third lock member 5j, the third lock spring 5k, and the third lock member 5j. 4h. When the rear end regulating member 5 is pressed in the direction of arrow C by the third lock portion, the rear end regulating member 5 and the slide cassette 4 are integrated with each other until the slide cassette 4 reaches a predetermined position. To move. The release of the third locking means will be described later.

  Next, the expansion / contraction operation of the paper feed cassette 2 according to the present embodiment will be described.

  First, an operation of shortening the sheet feeding cassette 2 from the A3 size specification to the A4 size specification, the B5 size specification, and the A5 size specification in a direction in which the length in the sheet feeding direction is shortened will be described.

  FIG. 13 is a perspective view showing a state when the paper feed cassette 2 is set to the A3 size specification. When changing the setting from this state to the A4 size specification, the rear end regulating lever 5a is pressed in the direction of arrow C.

  Accordingly, as shown in FIG. 7 described above, the rear end regulating lever 5a pushes the first lock member 4b, and as a result, the lock of the slide cassette 4 with respect to the main cassette 3 by the first lock portion is released.

  When the rear end regulating lever 5a is pressed in the direction of arrow C, the rear end regulating member 5 is locked to the slide cassette 4 by the third lock portion as shown in FIG. For this reason, when the rear end regulating lever 5a is continuously pressed thereafter, the rear end regulating member 5 and the slide cassette 4 are integrated and move in a direction in which the paper feed cassette 2 is shortened.

  As a result, the paper feed cassette 2 becomes the A4 size specification shown in FIG. Thereafter, when the rear end regulating lever 5a is continuously pushed in the direction of the arrow C, the slide cassette 4 is housed in the main cassette. At this time, the paper feed cassette 2 has a B5 size specification as shown in FIG. . That is, in the present embodiment, the slide cassette 4 is pulled out when a sheet having a size of B5 or larger is stored.

  By the way, when storing a sheet of B5 size or smaller, the rear end regulating lever 5a is continuously pushed in the direction of arrow C. Here, since the slide cassette 4 is stored in the main cassette at this time, only the rear end regulating member 5 is moved thereafter.

  Here, in order to move only the rear end regulating member 5 as described above, it is necessary to unlock the third lock member 5j. Therefore, in the present embodiment, as shown in FIG. 13, the unlocking member 3c protrudes from the bottom surface of the main cassette body 3a, and when the slide cassette 4 is stored, the unlocking member 3c is shown in FIG. It contacts the contact portion 5p shown in FIG.

  Then, after the contact portion 5p contacts the lock release member 3c as described above, when the rear end regulating member 5 is further pressed, the third lock member 5j is centered on the rotation shaft 5m while resisting the third lock spring 5k. Then, it rotates upward in the direction of the arrow in FIG. Thereby, the 3rd lock member 5j is released from the to-be-latched part 4h of the slide cassette main body 4a, and the lock | rock of the 3rd lock part with respect to the slide cassette 4 of the rear-end control member 5 is cancelled | released.

  As described above, after the slide cassette 4 is moved to the position corresponding to the B5 size specification stored in the main cassette at a predetermined position, when the rear end regulating member 5 is further pressed, the lock by the third lock portion is released. .

  Thereafter, when the rear end regulating lever 5a is further pushed in the direction of arrow C, the latch portion 5d of the second lock member 5h and the locked portion 4g on the slide cassette body 4a shown in FIG. The rear end regulating member 5 moves on the slide cassette 4 due to the shape of the teeth. Then, it eventually moves to A5 size specifications as shown in FIG.

  Next, an operation of extending the sheet feeding cassette 2 from the A5 size specification to the B5 size specification, the A4 size specification, and the A3 size specification in the direction of increasing the length in the sheet feeding direction will be described.

  As shown in FIG. 15, when changing the setting of the paper feed cassette 2 from the A5 size specification to the B5 size specification, the rear end regulating lever 5a is first pressed in the direction of the arrow B. Accordingly, as shown in FIG. 10 described above, the engagement protrusion 5t of the rear end regulating lever 5a lifts the second lock member 5h, and the lock of the rear end regulating member 5 with respect to the slide cassette 4 is released. As a result, the rear end regulating member 5 moves on the slide cassette 4, and the B5 size specification shown in FIG.

  When this position is reached, the contact of the lock release member 3c with the contact portion 5p is released, and the third lock member 5j is pivoted downward about the pivot shaft 5m by the third lock spring 5k, so that the third lock The member 5j engages with the locked portion 4h on the slide cassette body 4a. Thereby, the rear end regulating member 5 is locked with respect to the slide cassette 4.

  Next, when the rear end regulating lever 5a is further pressed in the arrow B direction, the rear end regulating lever 5a pushes the first lock member 4b as shown in FIG. 6 described above, and the slide cassette 4 is locked with respect to the main cassette 3. Canceled. Thereafter, when the rear end regulating lever 5a is continuously pushed in the direction of the arrow B, the rear end regulating member 5 and the slide cassette 4 are integrated as shown in FIG. 13 from the A4 size specification shown in FIG. The rear end regulating member 5 and the slide cassette 4 are moved together to the A3 size specification.

  FIG. 16 is a diagram showing an outline of the expansion / contraction operation of the paper feed cassette 2 according to the present embodiment described so far.

  FIG. 16A shows a state in which the slide cassette 4 is pulled out to a position corresponding to the maximum sheet size. In this state, the slide cassette 4 is locked to the main cassette 3 by the first lock portion (● mark), and the rear end regulating member 5 is locked to the slide cassette 4 by the third lock portion. It is in a state (● mark).

  FIG. 16 (b) shows a state after the rear end regulating lever 5a of the rear end regulating member 5 is operated in the direction of the arrow X. By operating the rear end regulating lever 5a in this way, 1 The lock portion is in a released state (circle mark), and the slide cassette 4 is stored in the main cassette.

  FIG. 16C shows a state immediately before the slide cassette 4 is housed in the main cassette. At this time, the third lock portion is still in the locked state (marked with ●). FIG. 16D shows a state immediately after the slide cassette 4 is accommodated in the main cassette. At this time, the third lock portion is in a released state (circle mark), and then the rear end regulating member 5 corresponds to the minimum sheet size shown in FIG. 16E by continuing to operate the rear end regulating lever 5a. Locked at the position.

  Thus, the slide operation of the rear end regulating member 5 (rear end regulating lever 5a) can unlock the slide cassette 4 with respect to the main cassette 3 and the rear end regulating member 5 with respect to the slide cassette 4.

  In other words, in the present embodiment, one operation of the rear end regulating lever 5a can simultaneously perform two operations, the rear end regulating operation by the rear end regulating member 5 and the expansion / contraction operation of the paper feed cassette 2. Will improve.

  In the present embodiment, the locked portion 3b of the main cassette body 3a meshing with the latch portion 4e of the first lock member 4b shown in FIG. 5 has a continuous shape according to the slide range of the slide cassette 4. ing. This is to enable correspondence between a size between A3 size and A4 size (for example, B4 size, other multi-size paper) and a size between A4 size and B5 size (for example, Letter size, other multi-size paper). It is. By configuring the locked portion 3b of the main cassette body 3a in this way, usability can be improved when a variety of sheet size specifications are required.

  Next, a second embodiment of the present invention will be described.

  FIG. 17 is a diagram showing a configuration of the paper feed cassette according to the present embodiment. In FIG. 17, the same reference numerals as those in FIG. 5 described above indicate the same or corresponding parts. FIG. 17 shows a state where the paper feed cassette 2 is set to the A3 specification.

  In FIG. 17, reference numerals 3b1 to 3b3 denote engagement recesses that are engaged portions formed on the side wall surfaces of the ribs 3d that are provided on the main cassette 3 and extend in the sheet feeding direction. In the present embodiment, the latch portion 4e of the first lock member 4b is engaged with the engagement recesses 3b1 to 3b3 by the biasing force of the first lock spring 4c.

  The engaging recess 3b1 is for pulling out the slide cassette 4 from the main cassette 3 and locking it at the A3 size position. The engaging recess 3b2 is for pulling out the slide cassette 4 from the main cassette 3 and locking it at the A4 size position shown in FIG. The engaging recess 3b3 is for pushing the slide cassette 4 into the main cassette 3 and locking it to the B5 size position shown in FIG.

  Also in the present embodiment, as in the first embodiment described above, two operations of the sheet trailing edge regulating operation and the operation of extending and contracting the sheet feeding cassette 2 by one operation of the trailing edge regulating lever 5a. Can be performed and usability is improved.

  Further, in the present embodiment, in order to align the main cassette 3 and the slide cassette 4, the engagement recesses 3b1 to 3b3 are provided with the slide position of the slide cassette 4 according to the size of the sheet to be stored, for example, A3, A4, B5. Provided. As a result, usability in the case of handling only the standard paper is improved.

1 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. FIG. 3 is a perspective view of a paper feed cassette attached to the color laser printer. FIG. The perspective view which shows the state which removed the rear end regulation member from the slide cassette of the said paper feed cassette. The top view which shows the state which removed the rear-end regulation member from the said slide cassette. The figure which shows a state when the rear-end control lever provided in the rear-end control member of the said rear-end control member attachment part is pressed in the slide cassette pull-out direction. The figure which shows a state when the rear-end control lever provided in the said rear-end control member is pressed in the slide cassette accommodation direction. The figure which shows the state by which the slide cassette was accommodated by pressing the said rear end control lever in a slide cassette accommodation direction. The figure explaining the 2nd lock | rock part of the said rear end regulating member. The figure which shows the state of a 2nd lock part when the said rear end control lever is pressed in the slide cassette accommodation direction. The perspective view explaining the structure of the 3rd lock part which locks the said rear-end control member to a slide cassette. 11A is a DD cross-sectional view, and FIG. 11B is an EE cross-sectional view. The perspective view which shows a state when the said paper feeding cassette is set to A3 size specification. (A) is a perspective view which shows the state when set to A4 size specification, (b) is a perspective view which shows the state when set to B5 size specification. The perspective view which shows a state when the said paper feeding cassette is set to A5 size specification. FIG. 4 is a diagram illustrating an outline of an expansion / contraction operation of a paper feed cassette according to the present embodiment. The figure which shows the structure of the paper feed cassette which concerns on the 2nd Embodiment of this invention. The figure which shows the state when (a) is set to A4 size specification, and (b) is the figure which shows the state when set to B5 size specification. The perspective view of the conventional expansion-contraction type paper feed cassette.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 1A Laser beam printer main body 1B Image formation part 1C Sheet feeding apparatus 2 Paper feed cassette 3 Main cassette 3b Locked part 3c Unlock member 4 Slide cassette 4a Slide cassette main body 4b First lock member 4c First lock spring 4e Latch part 4g Locked part 4h Locked part 5 Rear end regulating member 5a Rear end regulating lever 5d Latch part 5f Second lock spring 5h Second lock member 5j Third lock member 5k Third lock spring 5p Abutting part 3b1 3b3 engagement recess S sheet

Claims (10)

In a sheet feeding device for feeding sheets stored in a sheet feeding cassette,
The paper cassette is
The cassette body,
A slide cassette slidably provided on the cassette body;
A rear end regulating member that is slidably provided on the slide cassette and regulates a rear end of a sheet stored in the paper feed cassette;
A first lock portion for locking the slide cassette to the cassette body;
A second lock portion for locking the rear end regulating member on the slide cassette at a position corresponding to the size of a sheet to be stored;
A third locking portion that locks the rear end regulating member and the slide cassette so that the slide cassette slides integrally with the rear end regulating member when the rear end regulating member is slid;
The slide cassette in which the first lock portion and the second lock portion are unlocked in accordance with an operation of sliding the rear end regulating member, and the third lock portion slides in the sheet feeding direction together with the rear end regulating member. The sheet feeding device is characterized in that the lock is released when the position reaches a predetermined position.   When the slide cassette is slid, the rear end restricting member is pressed in the sliding direction to simultaneously unlock the first lock portion and the second lock portion, and slides only the rear end restricting member. The sheet feeding apparatus according to claim 1, further comprising a lever member to be moved.   The first lock portion is provided in the slide cassette and includes a first lock member that engages with the cassette body, and the second lock portion is provided in the rear end regulating member and is engaged with the slide cassette. 2. A second lock member that is engaged, wherein the first lock member and the second lock member move in a disengagement direction along with a pressing operation of the lever member in a slide direction. 2. A sheet feeding apparatus according to 2.   4. The sheet feeding apparatus according to claim 3, wherein the cassette body is provided with an engaged portion that engages with a first lock member of the first lock portion to lock the slide cassette.   The sheet feeding apparatus according to claim 4, wherein the engaged portion is provided according to a slide range of the slide cassette.   5. The sheet feeding apparatus according to claim 4, wherein the engaged portion is provided at a slide position of the slide cassette corresponding to a size of a sheet to be stored.   The third lock portion is provided on the rear end regulating member and includes a third lock member that engages with the slide cassette. The third lock member is a pressing operation of the lever member in the sheet feeding direction. Accordingly, after the slide cassette reaches the predetermined position, the lock is released by contact with a lock release member provided in the cassette body. The sheet feeding apparatus described in 1.   The slide cassette slides integrally with the rear end regulating member when the rear end regulating member is pressed to slide the slide cassette in a direction in which the paper feeding cassette is extended. 8. The sheet feeding apparatus according to any one of 7 above.   The sheet feeding apparatus according to claim 1, wherein the predetermined position is a position where the slide cassette is stored in the cassette body.   An image forming apparatus comprising: an image forming unit; and the sheet feeding device according to claim 1 for feeding a sheet to the image forming unit.

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