JP2017145109A - Sheet storage cassette and image formation apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet storage cassette which can suppress the deviation of a cursor member at the cassette insertion due to the weight of a sheet with a simple configuration, and an image formation apparatus having the same.SOLUTION: A sheet storage cassette includes: a housing; a cursor member; and a lock mechanism, and is detachably attached to an image formation apparatus body. The housing is formed of a cassette base and a plurality of side walls erected on the circumference of the cassette base, and stores a sheet-like recording medium. A cursor member is provided movably in the cassette base of the housing and performs positioning of the sheet by contacting the edge of the sheet stored in the housing. A lock mechanism regulates movement of the cursor member with respect to the cassette base when the sheets stored in the housing are equal to or greater than the prescribed number.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sheet storage cassette for storing a sheet-like recording medium used in an image forming apparatus such as a digital copying machine and a laser printer, and an image forming apparatus including the same.

  2. Description of the Related Art Conventionally, there are a wide variety of sheet feeding cassettes that stack and store a plurality of sheet-like sheets (recording media) and separate and convey sheets one by one to an image forming unit of an image forming apparatus main body according to an image forming operation. It is used. Such a paper feed cassette can be inserted into and pulled out from the image forming apparatus main body in consideration of operability when replenishing paper.

  In addition, a cursor member including a width alignment cursor and a rear end cursor for storing paper at a predetermined position in the paper feed cassette is disposed in the paper feed cassette. By moving these cursor members according to the size of the stacked paper, the paper is positioned at the paper feed position.

  Here, when the paper feeding cassette is inserted into the image forming apparatus main body with a large amount of paper loaded, a large load is applied to the cursor member due to the weight of the paper, and the cursor member may deviate from the position previously positioned. When the position of the cursor member is deviated, the paper position regulated by the cursor member is also deviated, which causes problems such as image position deviation and paper feed failure.

  Therefore, a method for preventing inadvertent movement of the cursor member has been proposed. For example, in Patent Document 1, a rack having sawtooth rack teeth is provided in parallel with the guide rail and attached to the rear end cursor. A paper feed cassette having a lock mechanism for engaging a lock lever with a rack at a predetermined position is disclosed. Patent Document 2 discloses a paper feed cassette in which the first guide member is fixed by concave and convex fitting, and the fixing by the concave and convex fitting is released by bending deformation of the first guide member. ing.

JP 2001-187642 A JP 2010-52903 A

  Even when a dedicated locking mechanism for locking the cursor member is provided as in Patent Documents 1 and 2, if the rack teeth or unevenness are shallowly engaged, the load applied to the cursor member during insertion of the paper feed cassette There is a possibility that the lock mechanism is disengaged and the cursor member is displaced.

  In addition, if a lock mechanism that can firmly lock the cursor member is provided, it is possible to prevent displacement of the cursor member, but if the user forgets to operate the lock mechanism, the cursor member will not be locked and the position of the paper in the paper cassette There was a risk of misalignment.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet storage cassette and an image forming apparatus including the sheet storage cassette that can suppress the displacement of a cursor member due to the weight of the sheet when the cassette is inserted with a simple configuration.

  In order to achieve the above object, a first configuration of the present invention is a sheet storage cassette that includes a housing, a cursor member, and a lock mechanism, and is detachably attached to the main body of the image forming apparatus. The housing is composed of a cassette base and a plurality of side walls erected on the peripheral edge of the cassette base, and accommodates a sheet-like recording medium. The cursor member is movably provided on the cassette base of the housing, and is in contact with the edge of the sheet stored in the housing to position the sheet, and extends inwardly from the lower end of the restriction surface along the base. And a support surface. The lock mechanism is an engagement member provided on the support surface of the cursor member so as to be swingable in the vertical direction, and is formed on the cassette base, and is engaged when the cursor member is disposed at a position where it abuts against an edge of a sheet of a predetermined size. An engaging groove facing the coupling member, and restricts movement of the cursor member relative to the cassette base. The engaging member is disposed at a first position that allows the movement of the cursor member by projecting upward from the support surface and separating from the engaging groove when the number of sheets stored in the housing is less than a predetermined number. When the number of sheets stored therein is equal to or greater than a predetermined number, the second position is set so as to be engaged with the engagement groove by restricting the movement of the cursor member by being buried below the support surface and engaging with the engagement groove. Be placed.

  According to the first configuration of the present invention, the engagement member is moved to the second position only by stacking a predetermined number of sheets or more by previously setting the cursor member at a position corresponding to the sheet size stored in the housing. The movement of the cursor member is restricted. Further, after the sheet storage cassette is inserted into the image forming apparatus, when the number of sheets is less than a predetermined number by the printing operation, the engaging member is disposed at the first position and the cursor member is automatically unlocked. Accordingly, it is possible to reliably prevent the displacement of the cursor member when inserting the sheet storage cassette into the image forming apparatus in a state where the number of stacked sheets (stacking amount) is large, and the image position displacement and sheet feeding failure caused by the displacement. Can do. Further, there is no need for an operation for the user to restrict (lock) the movement of the cursor member or an operation for releasing the lock when the sheet storage cassette is pulled out from the image forming apparatus to replenish the sheet.

1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus 100 in which a paper feed cassette 2 of the present invention is mounted. 1 is an external perspective view of a paper feed cassette 2 according to the first embodiment of the present invention. The top view of the paper feed cassette 2 of the first embodiment Side surface sectional drawing which cut | disconnected the paper feed cassette 2 of 1st Embodiment along the paper feed direction in the width regulation part 41 vicinity of the width alignment cursor 37a. Side sectional view of the width alignment cursor 37a cut along the paper width direction FIG. 5 is a partially enlarged view of the periphery of the lock mechanism 60 in FIG. 4, showing a state where the paper 26 is not stacked on the paper stacking plate 28. FIG. 5 is a partially enlarged view of the periphery of the lock mechanism 60 in FIG. 4, showing a state where a predetermined number of sheets 26 are stacked on the sheet stacking plate 28. The top view of the paper feed cassette 2 which concerns on 2nd Embodiment of this invention. Side surface sectional drawing which cut | disconnected the paper feed cassette 2 of 2nd Embodiment along the paper feed direction in the width regulation part 41 vicinity of the width alignment cursor 37a. FIG. 9 is a partially enlarged view of the periphery of a lock mechanism 60 in a paper feed cassette 2 according to a third embodiment of the present invention, and shows a state in which no paper is stacked on a paper stacking plate. FIG. 10 is a partially enlarged view of the periphery of the lock mechanism 60 in the paper feed cassette 2 of the third embodiment, and shows a state in which a predetermined number of sheets 26 are stacked on the sheet stacking plate 28.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 including a paper feed cassette 2 according to an embodiment of the present invention. Here, a monochrome multifunction peripheral is shown as the image forming apparatus 100. In the main body of the image forming apparatus 100, an image forming portion P for forming a monochrome image by each process of charging, exposure, development and transfer is disposed.

  In the image forming unit P, along the rotation direction of the photosensitive drum 1 (counterclockwise direction in FIG. 1), the charging unit 10, the exposure unit 3, the developing device 4, the transfer roller 7, the cleaning device 8, and the charge eliminating device. (Not shown) is provided. In the image forming unit P, the image forming process for the photosensitive drum 1 is executed while rotating the photosensitive drum 1 in the counterclockwise direction in FIG.

  When performing the copy operation, the image reading unit 21 reads the image data of the document and converts it into an image signal. On the other hand, in the image forming unit P, the photosensitive drum 1 that rotates counterclockwise in the drawing is uniformly charged by the charging unit 10. Then, the exposure unit 3 irradiates the photosensitive drum 1 with a laser beam (light beam) based on the document image data read by the image reading unit 21, whereby the electrostatic latent image based on the image data is converted into the photosensitive drum. 1 formed on the surface. Thereafter, the developing device 4 attaches toner to the electrostatic latent image to form a toner image.

  A sheet 26 is conveyed from the sheet feeding cassette 2 through the sheet conveying path 11 and the registration roller pair 13 at a predetermined timing toward the image forming section P on which the toner image is formed as described above. Then, the toner image on the surface of the photosensitive drum 1 is transferred onto the sheet by the transfer roller 7. The paper 26 onto which the toner image has been transferred is separated from the photosensitive drum 1, conveyed to the fixing unit 9, and heated and pressurized to fix the toner image on the paper 26.

  The paper 26 that has passed through the fixing unit 9 is distributed in the conveyance direction by the branching unit 16 that branches in a plurality of directions. When an image is formed on only one side of the paper 26, it is discharged as it is onto the discharge tray 15 by the discharge roller pair 14.

  On the other hand, when forming images on both sides of the paper 26, the paper 26 that has passed through the fixing unit 9 is once transported in the direction of the discharge roller pair 14, and after the trailing edge of the paper 26 passes through the branching portion 16, the discharge roller pair 14. Is rotated in the reverse direction and the conveyance direction of the branching portion 16 is switched, so that the paper 26 is distributed from the rear end of the paper 26 to the reverse conveyance path 17 and re-conveyed to the registration roller pair 13 with the image surface reversed. Then, the next image formed on the photosensitive drum 1 is transferred to the surface of the paper 26 where the image is not formed by the transfer roller 7 and conveyed to the fixing unit 9 to fix the toner image, and then the discharge tray. 15 is discharged.

  Next, the configuration of the paper feed cassette 2 will be described. 2 and 3 are a perspective view and a plan view, respectively, of the paper feed cassette 2 according to the first embodiment of the present invention, and FIG. 4 shows the paper feed cassette 2 in the vicinity of the width regulating portion 41 of the width alignment cursor 37a. FIG. 5 is a side cross-sectional view taken along the paper width direction (cross-sectional view taken along arrow AA in FIG. 3), and FIG. 5 is a side cross-sectional view taken along the paper width direction. 2 and 3, the insertion direction of the paper feed cassette 2 with respect to the image forming apparatus 100 is indicated by an arrow B, the pull-out direction is indicated by an arrow B ′, and the paper feed direction of the paper feed cassette 2 is indicated by an arrow C. The cassette base 25 constitutes a housing (housing) of the paper feed cassette 2 and has a tray shape in which side walls 25a to 25d are formed on four sides of a rectangular bottom surface.

  A cassette cover 33 is mounted on the side wall 25a on the downstream side with respect to the insertion direction of the paper feed cassette 2. The cassette cover 33 has a surface side (the left front side in FIG. 2) exposed to the outside and constitutes a part of the exterior surface of the image forming apparatus 100 (see FIG. 1) main body. FIG. 3 shows a state where the cassette cover 33 is removed.

  The paper stacking plate 28 on which the paper 26 (see FIG. 1) is loaded is supported by using the swing shaft 28a on the upstream side in the paper feeding direction (left side in FIG. 3) as a fulcrum, and downstream in the paper feeding direction (in FIG. 3). An end portion on the right side is provided so as to be movable up and down with respect to the cassette base 25 by a coil spring (not shown).

  On both sides in the width direction of the paper stacking plate 28, a pair of width alignment cursors 37 a and 37 b for positioning the paper 26 stacked on the paper stacking plate 28 in the width direction are formed in guide grooves 38 a formed on the bottom surface of the cassette base 25. Along the sheet width direction (in the direction of arrow BB 'in the figure).

  The width alignment cursors 37a and 37b extend in a horizontal direction from a width restricting portion 41 that stands vertically from the bottom surface of the cassette base 25 and from a lower end portion of the width restricting portion 41, and are arranged along the guide groove 38a. The shape seen from the paper feeding direction (right direction in FIG. 3) is substantially L-shaped. The width restricting portion 41 contacts the side edge of the paper 26 placed on the paper stacking plate 28. Rack teeth extending in the paper width direction are formed on the opposing surfaces of the rack portions 43 in the paper feeding direction.

  As the width restricting portion 41 slides in the paper width direction (vertical direction in FIG. 3), the rack portion 43 also moves in the paper width direction. Note that the rack portions 43 of the two width alignment cursors 37a and 37b are arranged with their positions shifted in the paper feeding direction (left and right direction in FIG. 3), so that they collide with each other even if they move in the paper width direction. Never do.

  One width alignment cursor 37a is moved in the paper width direction by a rack and pinion mechanism constituted by a pinion gear (not shown) arranged at a substantially central portion of the cassette base 25 and rack teeth of each rack portion 43. In conjunction with this, the other width alignment cursor 37b also moves in the opposite direction. That is, the width alignment cursors 37 and 37b move symmetrically with respect to the center line in the paper width direction.

  Further, the width adjusting cursor 37a is provided with a position regulating mechanism 50 for fixing the width adjusting cursors 37a and 37b to the cassette base 25 at arbitrary positions. As shown in FIG. 5, the position restricting mechanism 50 includes a position restricting portion 45 provided on the back side of the width restricting portion 41 (on the side opposite to the sheet contact surface), and the width restricting portion 41 and the position restricting portion 45. A coil spring 46 disposed therebetween.

  An engaging claw 45 a is formed at the lower end of the position restricting portion 45. The engaging claw 45a is formed so as to engage with the rack teeth 25e formed continuously along the guide groove 38a (see FIG. 3) on the bottom surface of the cassette base 25. Then, with the movement of the width alignment cursor 37a, the engagement positions of the engagement claws 45a and the rack teeth 25e move. A lever portion 45 b is formed above the position restricting portion 45.

  In the state of FIG. 5 in which no force is applied to the lever portion 45b, the engaging claw 45a protrudes from the lower end of the width alignment cursor 37a by the biasing force of the coil spring 46 and engages with the rack teeth 25e formed on the bottom surface of the cassette base 25. ing. As a result, the movement of the width alignment cursor 37a in the paper width direction is restricted. As described above, since the width alignment cursor 37b moves in conjunction with the width alignment cursor 37a by the rack and pinion mechanism, the movement of the width alignment cursor 37b is also restricted by restricting the movement of the width alignment cursor 37a.

  When the lever part 45b of the position restricting part 45 is gripped together with the width restricting part 41 from the state of FIG. 5, the position restricting part 45 is elastically deformed toward the width restricting part 41 with respect to the cassette base 25 together with the lever part 45b. As a result, the engaging claw 45a is retracted upward, the engagement with the rack tooth 25e is released, and the width alignment cursors 37a and 37b can be moved.

  After the width adjusting cursors 37a and 37b are moved in accordance with the width of the paper 26, the engaging claws 45a are again moved from the lower end of the width adjusting cursor 37a by the biasing force of the coil spring 46 by releasing the finger holding the lever portion 45b. Protrudes and engages with the rack teeth 25e. As a result, the width alignment cursors 37a and 37b are held at predetermined positions in the paper width direction.

  Further, since the paper 26 is sent in the direction of the arrow B ′ (see FIG. 2) toward the paper transport path 11 (see FIG. 1), a rear end cursor 31 for aligning the rear end of the paper 26 is formed on the cassette base 25. The guide groove 38b is provided so as to be reciprocally movable in parallel with the paper feeding direction (the direction of arrow C in FIG. 3). Although explanation is omitted here, the rear end cursor 31 is also provided with a position regulating mechanism having the same configuration as the width alignment cursor 37a.

  By moving the width alignment cursors 37a and 37b and the rear end cursor 31 in accordance with the size of the paper 26 stacked on the paper stacking plate 28, the paper 26 is stored in a predetermined position in the paper feed cassette 2.

  As described above, the position adjusting mechanism 50 is provided in the width alignment cursors 37a and 37b. However, when a load is applied in the movement direction of the width alignment cursors 37a and 37b, the engagement between the engagement claws 45a and the rack teeth 25e. Mismatch may occur. In particular, as described above, when the insertion direction of the paper feed cassette 2 and the paper feed direction are orthogonal to each other, the width alignment cursors 37a and 37b move along the insertion direction of the paper feed cassette 2. When the paper feed cassette 2 is inserted into the main body of the image forming apparatus 100 with a large amount of paper 26 loaded, a large load is applied to the width alignment cursor 37a positioned downstream from the paper 26 with respect to the insertion direction due to an impact at the time of insertion. There is a possibility that the width alignment cursor 37a and the width alignment cursor 37b connected to the width alignment cursor 37a by the rack and pinion mechanism may be shifted.

  Therefore, the end of the width alignment cursor 37a on the upstream side in the paper feeding direction is for restricting (locking) the movement of the width alignment cursor 37a with respect to the cassette base 25 according to the stacking amount of the paper 26 on the paper stacking plate 28. A lock mechanism 60 is provided. Hereinafter, a detailed configuration of the lock mechanism 60 will be described.

  6 and 7 are partially enlarged views of the periphery of the lock mechanism 60 in FIG. 4 (inside the broken-line circle S in FIG. 4). FIG. 6 shows a state in which the paper 26 is not stacked on the paper stacking plate 28, and FIG. 7 shows a state in which a predetermined number of sheets 26 or more are stacked on the paper stacking plate 28. In FIG. 7, the description of the paper 26 is omitted.

  The lock mechanism 60 is supported by an engagement member support 47 that protrudes along the bottom surface of the cassette base 25 inward from the lower end of the rear end in the paper feeding direction of the width regulating portion 41 of the width alignment cursor 37a. It includes an engaging member 61, an engaging groove 63 formed on the cassette base 25 side, and a compression spring 65. The engaging member 61 is a bar-like or plate-like member having a V-shape when viewed from the side, and has a fulcrum portion 61a that is swingably supported by the engaging member support portion 47 and a convex shape upward from the fulcrum portion 61a. And a bent portion 61b extending to the center. The engagement groove 63 has such a groove width that the engagement member 61 can be inserted in the width direction (direction perpendicular to the paper surface of FIG. 6).

The engaging groove 63 is formed at a position facing the swinging end 61c (left end in FIGS. 6 and 7) of the engaging member 61 in the paper feeding direction of the cassette base 25 (the left-right direction in FIGS. 6 and 7). ing. Also, the movement direction of the width alignment cursor 37a (paper width direction, the direction perpendicular to the paper surface of FIGS. 6 and 7).
In FIG. 4, a plurality of types of standard-size paper 26 are formed at predetermined intervals along the paper width direction according to the width-wise dimensions. The engaging member support 47 is also formed with a slit 47a through which the bent portion 61b of the engaging member 61 can pass.

  The compression spring 65 is disposed between the engagement member support portion 47 and the engagement member 61 and biases the engagement member 61 in a direction protruding from the cassette base 25 (upward direction in FIGS. 6 and 7). .

  In a state where the paper 26 is not stacked on the paper stacking plate 28, the bent portion 61b of the engaging member 61 protrudes from the cassette base 25 by the urging force of the compression spring 65 as shown in FIG. The bent portion 61 b of 61 is disposed at a position (first position) retracted above the engagement groove 63. Further, the protruding amount of the bent portion 61b is restricted by the swinging end 61c of the engaging member 61 being engaged with the opening edge of the slit 47a. In this state, the width alignment cursor 37a is not locked by the lock mechanism 60, and can be reciprocated along the paper width direction by releasing the position restriction mechanism 50.

  When a predetermined number of sheets 26 or more are stacked on the sheet stacking plate 28 from the state of FIG. 6, the bent portion 61 b of the engaging member 61 is pressed against the sheet 26, and the engaging member 61 is subjected to the urging force of the compression spring 65. Accordingly, it swings counterclockwise in FIG. 6 around the fulcrum 61a. As a result, as shown in FIG. 7, the rocking end 61c of the engaging member 61 is disposed at a position (second position) where it engages with the engaging groove 63, and the width alignment cursor 37a is locked. Further, when the width alignment cursor 37a is locked, the width alignment cursor 37b is also locked.

  After the paper cassette 2 containing a predetermined number of sheets 26 or more is inserted into the image forming apparatus 100, the load on the sheet 26 is reduced when the number of sheets 26 is reduced by the printing operation. It swings clockwise from the state of FIG. 7 by the urging force. As a result, as shown in FIG. 6 again, the swinging end 61c of the engagement member 61 is retracted above the engagement groove 63, and the lock of the width alignment cursor 37a is released.

  According to the configuration of the present embodiment, the width alignment cursors 37a and 37b are set to positions corresponding to the size of the paper 26 to be stored in advance, and only a predetermined number of papers 26 are stacked on the paper stacking plate 28. The joint member 61 and the engagement groove 63 are engaged to restrict the movement of the width alignment cursors 37a and 37b. Therefore, an operation for restricting (locking) the movement of the width alignment cursors 37a and 37b by the user is not necessary.

  Further, as the number of sheets 26 stacked (the amount loaded) increases, the impact applied to the width alignment cursor 37a when the sheet feeding cassette 2 is inserted increases. Along with this, the swinging amount of the engaging member 61 increases, and the swinging end 61 c of the engaging member 61 enters deeper into the engaging groove 63. Accordingly, since the width alignment cursor 37a is firmly fixed by the lock mechanism 60, the width alignment cursor 37a when inserting the paper feed cassette 2 into the image forming apparatus 100 with the paper 26 fully loaded on the paper stacking plate 28, It is possible to reliably prevent the positional deviation 37b, the image positional deviation caused by the positional deviation, and the paper feeding failure.

  Further, after the paper feeding cassette 2 is inserted into the image forming apparatus 100, when the paper 26 is reduced by the printing operation, the lock of the width alignment cursors 37a and 37b by the lock mechanism 60 is automatically released, so the image forming apparatus 100 When the paper cassette 2 is pulled out from the paper cassette 26 and the paper 26 is replenished, only the position restricting mechanism 50 needs to be released as in the prior art, and the operation of releasing the lock mechanism 60 is not required.

  Further, even if the paper 26 is reduced by the printing operation and the lock mechanism 60 is released, the movement of the width alignment cursors 37a and 37b is restricted by the position restriction mechanism 50, so that an image misalignment or a paper feed failure occurs. There is no risk.

  FIG. 8 is a plan view of the paper feed cassette 2 according to the second embodiment of the present invention, and FIG. 9 is a diagram illustrating how the paper feed cassette 2 of the second embodiment is fed by the width regulating portion 41 near the width alignment cursor 37a. It is side surface sectional drawing (AA sectional view taken on the line of FIG. 8) cut | disconnected along the direction. In the present embodiment, the lock mechanisms 60 are provided at two locations on the upstream side and the downstream side in the paper feeding direction of the width alignment cursor 37a. The configuration of the lock mechanism 60 is the same as that of the first embodiment shown in FIGS.

  According to the configuration of the present embodiment, the width alignment cursor 37a can be locked on both the front end side of the paper (downstream side in the paper feed direction) and the rear end side of the paper (upstream side in the paper feed direction). Therefore, even in the width alignment cursor 37a having a long dimension of the width regulating portion 41 in the paper feeding direction, it is possible to effectively prevent the positional deviation of the paper 26 on both the upstream side and the downstream side in the paper feeding direction.

  10 and 11 are partially enlarged views of the periphery of the lock mechanism 60 in the paper feed cassette 2 according to the third embodiment of the present invention. FIG. 10 shows a state where the paper 26 is not stacked on the paper stacking plate 28, and FIG. 11 shows a state where a predetermined number of sheets 26 or more are stacked on the paper stacking plate 28. In FIG. 11, the paper 26 is not shown.

  In the present embodiment, the lock mechanism 60 does not include the compression spring 65, and the engaging member 61 is formed of an elastically deformable material such as a leaf spring. The fulcrum portion 61 a of the engagement member 61 is fixed to the engagement member support portion 47. The configuration of the other parts of the paper feed cassette 2 is the same as that of the first embodiment.

  In a state where the paper 26 is not stacked on the paper stacking plate 28, as shown in FIG. 10, the bent portion 61b of the engaging member 61 protrudes from the cassette base 25, and the swing end 61c of the engaging member 61 is It is disposed at a position (first position) retracted above the engagement groove 63. In this state, the width alignment cursors 37a and 37b are not locked and can be reciprocated along the paper width direction.

  When a predetermined number of sheets 26 or more are stacked on the sheet stacking plate 28 from the state of FIG. 10, the bent portion 61b of the engaging member 61 is pressed against the sheet 26, and the engaging member 61 is elastically deformed to be a fulcrum portion 61a. Oscillates counterclockwise in FIG. As a result, as shown in FIG. 11, the swinging end 61c of the engaging member 61 is disposed at the position (second position) where it engages with the engaging groove 63, and the width alignment cursor 37a is locked. Further, when the width alignment cursor 37a is locked, the width alignment cursor 37b is also locked.

  According to the configuration of the present embodiment, similarly to the first embodiment, the width alignment cursors 37a and 37b when inserting the paper feed cassette 2 into the image forming apparatus 100 in a state where the number of stacked sheets 26 (stacked amount) is large. Misalignment, and image misalignment and paper feed failure caused by the misalignment can be reliably prevented. Further, it is not necessary for the user to restrict (lock) the movement of the width alignment cursors 37a and 37b or to release the lock when the paper cassette 2 is pulled out from the image forming apparatus 100 to replenish paper.

  In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the embodiments described above, the lock mechanism 60 for the width alignment cursors 37a and 37b that regulates the position of the paper 26 in the width direction is provided, but together with the width alignment cursors 37a and 37b or on the width alignment cursors 37a and 37b. Instead, a lock mechanism 60 for the rear end cursor 31 that regulates the position of the rear end of the paper 26 may be provided. Further, in the first embodiment, the spring constant of the compression spring 65 is changed, and in the third embodiment, the elastic modulus (elastic coefficient) of the engaging member 61 is changed, so that according to the specifications of the paper feed cassette 2. It is possible to appropriately change the number of stacked sheets 26 (loading amount) on which the width alignment cursors 37a and 37b are locked.

  In the present invention, the paper feed cassette 2 in which the width alignment cursors 37a and 37b move along the insertion direction of the paper feed cassette 2 has been described. However, the insertion direction of the paper feed cassette 2 and the movement direction of the width alignment cursors 37a and 37b are described. The present invention is also applicable to a paper feed cassette in which the two are orthogonal. In addition, the present invention is not limited to the monochrome printer shown in FIG. 1, and is not limited to a monochrome multifunction device, a color printer, a color multifunction device, or a color multifunction device or color printer having an inkjet image forming unit. The present invention can also be applied to other image forming apparatuses having a paper feed cassette.

  The present invention is applicable to a sheet storage cassette that stores a sheet-like recording medium and an image forming apparatus including the sheet storage cassette. By using the present invention, it is possible to provide a sheet storage cassette capable of suppressing the displacement of the cursor member when inserting the cassette due to the weight of the sheet with a simple configuration, and an image forming apparatus including the sheet storage cassette.

2 Paper cassette (sheet storage cassette)
25 Cassette base (housing)
25a-25d side wall (housing)
25e Rack teeth (engaged part)
26 Paper
28 Paper loading plate 31 Rear end cursor (cursor member)
37a, 37b Width adjustment cursor (cursor member)
41 Width regulation part (regulation side)
43 Rack (support surface)
45 Position restriction part 45a Engagement claw 50 Position restriction mechanism 60 Lock mechanism 61 Engagement member 61a Supporting part 61b Bending part 61c Swing end 63 Engagement groove 65 Compression spring (biasing member)
100 Image forming apparatus

Claims (6)

A housing configured to include a cassette base and a plurality of side walls erected on the peripheral edge of the cassette base, and to store a sheet-like recording medium;
A regulating surface that is movably provided on the cassette base of the housing and that contacts the edge of the sheet stored in the housing to position the sheet, and extends inwardly from the lower end of the regulating surface along the base A cursor member having a support surface;
In a sheet storage cassette that is detachably attached to the image forming apparatus main body,
An engagement member provided on the support surface of the cursor member so as to be swingable in the vertical direction;
An engagement groove formed on the cassette base and facing the engagement member when the cursor member is disposed at a position where the cursor member abuts against an edge of a sheet of a predetermined size;
Comprising a lock mechanism for restricting movement of the cursor member relative to the cassette base,
The engaging member is a first position that allows the cursor member to move by protruding above the support surface and separating from the engaging groove when the number of sheets stored in the housing is less than a predetermined number. A second position that restricts movement of the cursor member by being buried below the support surface and engaging with the engagement groove when the number of sheets stored in the housing is equal to or greater than a predetermined number. The sheet storage cassette is characterized by being arranged in.   The engaging member is formed on a fulcrum portion that is swingably supported by the support surface, a bent portion that extends upward from the fulcrum portion, and an opposite side of the bent portion to the fulcrum portion. 2. The sheet storage cassette according to claim 1, wherein the swing end engages with the engagement groove at the second position.   The lock mechanism includes a biasing member that biases the engagement member in the first position direction, and the engagement member is biased when the number of sheets stored in the housing is less than a predetermined number. When the number of sheets disposed in the first position by the biasing force of the member and accommodated in the housing exceeds a predetermined number, the engagement member resists the biasing force of the biasing member. The sheet storage cassette according to claim 1, wherein the sheet storage cassette is disposed in a position.   The engaging member is made of an elastically deformable material, and is disposed at the first position when the number of sheets stored in the housing is less than a predetermined number, and the predetermined number of sheets stored in the housing is 3. The sheet storage cassette according to claim 1, wherein the engaging member is disposed at the second position by elastic deformation.   5. The pair of width alignment cursors, wherein the cursor members are positioned in the width direction of the sheet by contacting an edge in the width direction of the sheet stored in the housing. The sheet storage cassette according to any one of the above.   An image forming apparatus comprising the sheet storage cassette according to claim 1.

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