JP5740515B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet feeding device that stores and feeds a sheet bundle, and an image forming apparatus including the sheet feeding device.

  A sheet feeding device such as a paper feeding device built in an image forming apparatus such as a copying machine, a facsimile machine, or a printer is configured to feed paper one by one from a bundle of paper stored in the paper feeding device. The fed paper is fed to an image forming unit in the image forming apparatus, and an image on which image forming processing has been performed is transferred.

  As a paper feed cassette provided in such a paper feed device, one that can change the length of the cassette in accordance with the paper size is known. For example, a paper feed cassette described in Patent Document 1 includes a base cassette and a slide cassette that is slidably attached to the base cassette, and a pair of pin-like members are provided on both side walls of the base cassette. The base cassette is provided so as to be able to appear and disappear in the width direction, and grooved hook-shaped members are arranged on both side walls of the slide cassette at the two-stage lock positions. The slide cassette is expanded or contracted so that the groove of the hook-shaped member at any lock position is opposed to the pin-shaped member, and then the pin-shaped member is fitted into the groove so that the slide cassette is at the base cassette at any lock position Can be fixed to.

  On the other hand, the paper feed cassette described in Patent Document 2 includes a plurality of locking holes formed in the bottom wall of the base cassette for multi-stage locking, and a lock button provided in a slidable cassette expansion / contraction section. And have. By selectively fitting a lock button into one of the locking holes, the cassette expansion / contraction part can be fixed to the base cassette at a multi-stage lock position.

Japanese Patent Laid-Open No. 11-29211 JP 2001-97561 A

  However, in the paper feed cassette described in Patent Document 1, in order to fix the slide cassette in the lock position, hook-shaped members are disposed on both side walls of the slide cassette, and a pair of slidable pin-shaped members are provided on the base cassette side. Since it is provided, there is a problem that the structure is complicated and the number of parts increases.

  Further, in the paper feed cassette described in Patent Document 2, a space for forming a plurality of locking holes is required on the bottom wall of the base cassette for multi-stage locking, so that the base cassette becomes longer in the paper feed direction. At the same time, there is a problem that the base cassette must be enlarged in order to ensure the strength around the plurality of locking holes of the base cassette.

  Furthermore, in these and the paper feed cassettes described in Patent Documents 1 and 2, since the operation part for locking the slide cassette is hidden from the outside by the outer peripheral wall of the slide cassette, the cassette can be easily expanded and contracted. There is a problem that can not be.

  The present invention has been made to solve the above-described problems, and can provide a sheet feeding apparatus that can achieve downsizing of the apparatus with a simple configuration and that can easily expand and contract the cassette size. Objective.

Sheet feeding apparatus of the present invention includes a feeding cassette for accommodating sheets, a sheet feeding apparatus for feeding sheets from the feed cassette, the feeding cassette houses the sheets in a stacked state a base cassette having an opening at the upstream end of the feeding direction of the sheet,
A slide cassette that is slidably attached to the base cassette , wherein an upstream end of the slide cassette is stored in the base cassette and an upstream end of the slide cassette passes through the opening. A slide cassette that is movable between a second position protruding outward, and a rear end restriction that is provided on an upper surface of the slide cassette and restricts a rear end of the sheet stored in the base cassette in the feeding direction. A first fixing portion that positions and fixes the slide cassette at the first position, and the first fixing portion is an upstream end portion of the slide cassette in the feeding direction or the end thereof. a support portion protruding from the vicinity to the width direction of the slide cassette, and the convex portion provided on the support portion, the opening of the base cassette Formed in the bottom wall near has a engageable with the through hole the convex portion, the first fixing portion, the state in which the upper end portion of the convex portion is exposed upward through the through hole The first posture in which the convex portion and the through hole are engaged, and the support portion is deformed when the upper end portion of the convex portion is pressed by the user, and the engagement between the convex portion and the through hole is released. The posture can be changed between the second posture and the slide cassette is in the first position. When the slide cassette is in the first position, the first fixing portion is in the first posture, and the slide cassette is moved from the first position. When moving to the second position, the first fixed portion takes a second posture, and allows the user to pull the slide cassette to the second position with the convex portion, When the slide cassette is in the second position, the convex portion , Characterized in that away from said base cassette (claim 1).

  According to this configuration, the opening is formed at the upstream end in the feeding direction in the storage portion of the base cassette. And the 1st fixing | fixed part which positions and fixes a slide cassette to the 1st position where the upstream edge part of the said slide cassette was accommodated in the base cassette is a support part which protrudes in the width direction of a slide cassette, and the upper surface of the said support part And a through hole formed in the bottom wall near the opening of the base cassette. When the slide cassette is in the first position, the convex portion engages with the through hole on the base cassette side. Since the upper end part of the convex part at this time is exposed upward through the through hole, it can be pressed by a finger or the like. On the other hand, when the slide cassette is positioned at the second position where the upstream end of the slide cassette protrudes outward from the opening of the base cassette, the convex portion is separated from the base cassette. This eliminates the need for a through-hole or the like that engages at the second position on the base cassette side, so that the structure can be simplified and the strength can be ensured, so that the base cassette can be downsized.

In addition, when the slide cassette is in the first position , the first fixing portion takes a first posture in which the convex portion engages with the through hole with the upper end portion of the convex portion exposed upward through the through hole. . At this time, since the convex portion pressed by a finger or the like is located near the opening of the base cassette, it is possible to easily release the engagement between the convex portion and the through hole by pressing the convex portion, The slide cassette can be easily pulled out.

And the convex part is connected with the slide cassette via the support part, and is separated from the slide cassette in the width direction. Therefore, it is possible to easily operate the convex portion without being obstructed by the slide cassette or the rear end regulating member.

  Further, when the slide cassette is located at the second position protruding outward from the base cassette, the convex portion is separated from the base cassette, so that the slide cassette returns from the second position to the first position. Sometimes it is not necessary to press the convex portion.

When the slide cassette moves from the first position to the second position, the support portion of the first fixed portion is deformed when the upper end portion of the convex portion is pressed by the user, and the relationship between the convex portion and the through hole is increased. Take the 2nd posture to cancel the match. Since the second posture allows the user to pull out the slide cassette to the second position with a convex portion, the operation is simple. Further, when pulling out the slide cassette to the second position, it is possible to easily move the slide cassette to the second position by grasping the rear end regulating member provided on the upper surface of the slide cassette through the opening of the base cassette. is there.

  It is preferable that the convex portion is formed of a cylindrical or polygonal columnar protrusion.

  According to this configuration, since the convex portion is formed of a columnar or polygonal columnar projection, the slide cassette can be positioned in all the in-plane directions and the turning direction of the slide cassette, and the first fixing portion By fitting the projection and the through hole, it is possible to prevent the play in all the in-plane directions and the turning direction of the slide cassette when the slide cassette is fixed at the first position. Furthermore, since the convex portion is a columnar shape or a polygonal column shape, it is easy to visually recognize the inside of the storage portion of the base cassette.

  It is preferable to further include a second fixing portion that positions and fixes the slide cassette at the second position.

  According to this configuration, the slide cassette can be reliably positioned and fixed at the second position by the second fixing portion. Moreover, it is possible to install a second fixing portion that positions and fixes the slide cassette at the second position at a position away from the first fixing portion, and the first fixing portion can be further simplified and miniaturized. It becomes possible.

  An image forming apparatus according to the present invention includes the sheet feeding device described above and an image forming unit that forms an image on a sheet fed by the sheet feeding device.

  According to this configuration, since the image forming apparatus includes the sheet feeding device described above, the cassette size can be easily expanded and contracted while the apparatus is downsized with a simple configuration.

  According to the present invention, the cassette size can be easily expanded and contracted while reducing the size of the apparatus with a simple configuration.

1 is a side view schematically showing an internal configuration of an image forming apparatus including a sheet feeding unit according to an embodiment of a sheet feeding apparatus of the present invention. It is sectional drawing of the paper feed unit of FIG. FIG. 2 is a perspective view showing a state where a slide cassette is in a first position in the paper feeding unit of FIG. 1. FIG. 3 is a perspective view of a state where a slide cassette is in a second position in the paper feeding unit of FIG. 1. It is a perspective view of the base cassette of FIG. It is a perspective view of the slide cassette of FIG. 3, the support part of a 1st fixing | fixed part, and a lock button. FIG. 4 is a perspective view of a rear end regulating member in FIG. 3. FIG. 4 is a view of the slide cassette assembly of FIG. 3 as viewed obliquely from above. It is the figure which looked at the slide cassette assembly of FIG. 3 from diagonally downward. FIG. 4 is a view of a state in which a slide cassette assembly is mounted on the base cassette of FIG. 3 as viewed obliquely from below. FIG. 4 is an enlarged perspective view showing a state where the slide cassette is in a first position in the paper feeding unit of FIG. 3. FIG. 4 is an enlarged perspective view showing a state in which the slide cassette is in a second position in the paper feeding unit of FIG. FIG. 13 is an enlarged cross-sectional view illustrating a state in which the slide cassette of FIG. 12 is fixed at a second position by a second fixing portion.

  Hereinafter, an embodiment of an image forming apparatus including a sheet feeding unit according to an embodiment of a sheet feeding apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of an image forming apparatus including a paper feeding unit 19 according to an embodiment of the present invention. The image forming apparatus shown in FIG. 1 is a color printer. However, the present invention is not limited to this, and a copier, a monochrome printer, a facsimile, a multifunction machine having these functions, or a copy sheet (FIG. 2). Another apparatus for forming an image on a sheet such as paper P) may be used.

  The color printer 100 includes a printer main body 200 connected to an external device such as a personal computer (PC) directly or via a LAN, and a plurality of paper feeding units 19 provided below the printer main body 200. The color printer 100 is configured by combining a first housing 111 that houses various devices for forming an image on a sheet such as paper P and a second housing 112 that forms the outer surface of the paper feeding unit 19. Is done. A sheet feeding cassette 81 that houses sheets to be subjected to image forming processing is housed in the lower portion of the first housing 111. The paper feed cassette 81 is also accommodated in the second housing 112. Each sheet cassette 81 may store sheets of different sizes or different types of sheets. The paper feed cassette 81 can be pulled out from the first housing 111 and the second housing 112 by sliding to the right in FIG.

  The color printer 100 further includes a control circuit (not shown) for controlling the operation of the color printer 100 and other elements provided in a general color printer.

  The printer main body 200 includes toner containers 900Y, 900M, 900C, and 900K, an intermediate transfer unit 192, an image forming unit 93, an exposure unit 94, a paper feed unit 19, a fixing unit 97, a paper discharge unit 96, a first casing 111, Two housings 112, a top cover 911 and a front cover 912 are provided.

  The image forming unit 93 includes a yellow toner container 900Y, a magenta toner container 900M, a cyan toner container 900C, and a black toner container 900K. Below these containers, developing devices 10Y, 10M, 10C, and 10K corresponding to the respective colors of YMCK are disposed.

  The image forming unit 93 includes a photosensitive drum 17 (a photosensitive member on which a latent image is formed by an electrophotographic method) that carries a toner image of each color. As the photosensitive drum 17, a photosensitive drum using an amorphous silicon (a-Si) material can be used. The photosensitive drums 17 are supplied with yellow, magenta, cyan, and black toners from the toner containers 900Y, 900M, 900C, and 900K, respectively.

  Around the photosensitive drum 17, a charger 16, a developing device 10 (10Y, 10M, 10C, 10K), a transfer device (transfer roller) 119, and a cleaning device 18 are arranged. The charger 16 uniformly charges the surface of the photosensitive drum 17. The surface of the photosensitive drum 17 after charging is exposed by an exposure unit 94 to form an electrostatic latent image. The developing devices 10Y, 10M, 10C, and 10K develop the electrostatic latent images formed on the respective photosensitive drums 17 using the toners of the respective colors supplied from the toner containers 900Y, 900M, 900C, and 900K, respectively ( Visualization). The transfer roller 119 forms a nip portion with the photosensitive drum 17 with the intermediate transfer belt 921 interposed therebetween, and primarily transfers the toner image on the photosensitive drum 17 onto the intermediate transfer belt 921. The cleaning device 18 cleans the peripheral surface of the photosensitive drum 17 after the toner image is transferred.

  Each developing device 10Y, 10M, 10C, 10K includes a housing 20. A two-component developer having a magnetic carrier and toner is accommodated in the housing 20. In the housing 20, two agitating rollers 11 and 12 (developer agitating members) are rotatably arranged in parallel near the bottom of the housing 20 with the longitudinal direction as an axial direction.

  A developer circulation path is set on the inner bottom surface of the housing 20, and the stirring rollers 11 and 12 are disposed in the circulation path. A partition wall 201 erected from the bottom of the housing 20 is provided in the axial direction between the stirring rollers 11 and 12. The partition wall 201 divides the circulation path. A circulation path is formed so as to circulate around the partition wall 201. The two-component developer is charged while being stirred and conveyed on the circulation path by the stirring rollers 11 and 12.

  The two-component developer circulates in the housing 20 while being stirred by the stirring rollers 11 and 12, and the toner is charged. The two-component developer on the stirring roller 11 is attracted and conveyed by the magnetic roller 14 located on the upper side. The sucked two-component developer forms a magnetic brush (not shown) on the magnetic roller 14. The layer thickness of the magnetic brush is regulated by the doctor blade 13. The toner layer on the developing roller 15 is formed by a potential difference between the magnetic roller 14 and the developing roller 15. The electrostatic latent image on the photosensitive drum 17 is developed by the toner layer.

  The exposure unit 94 includes various optical system devices such as a light source, a polygon mirror, a reflection mirror, and a deflection mirror. Light based on image data is provided on the peripheral surface of the photosensitive drum 17 provided in each of the image forming units 93. To form an electrostatic latent image.

  The intermediate transfer unit 192 includes an intermediate transfer belt 921, a driving roller 922, and a driven roller 923. On the intermediate transfer belt 921, toner images are overcoated from a plurality of photosensitive drums 17 (primary transfer). The overcoated toner image is secondarily transferred to the sheet supplied from the paper feed cassette 81 by the secondary transfer unit 98. The driving roller 922 and the driven roller 923 drive the intermediate transfer belt 921 to rotate. The driving roller 922 and the driven roller 923 are rotatably supported by the first casing 111.

  The fixing unit 97 performs a fixing process on the toner image on the sheet secondarily transferred from the intermediate transfer unit 192. The sheet with the color image that has been subjected to the fixing process is discharged toward a paper discharge unit 96 formed at the top of the printer main body 200.

  The paper discharge unit 96 discharges the sheet conveyed from the fixing unit 97 onto a top cover 911 used as a paper discharge tray.

(Description of paper feeding unit 19)
Next, the paper feeding unit 19 will be described in detail. FIG. 2 is a cross-sectional view showing the configuration of the paper feed unit 19. FIG. 3 is a perspective view of the paper feeding unit 19.

  As shown in FIGS. 2 and 3, the paper feeding unit 19 includes a paper feeding cassette 81 that stores the paper P, and feeds the paper P from the paper feeding cassette 81 in the paper feeding direction D <b> 1.

  2 to 3 includes a base cassette 82, a slide cassette 71, a rear end regulating member 33, a first fixing portion 91, and a second fixing portion 92 (see FIGS. 12 to 13). It has.

  A slide cassette assembly 79 is configured by attaching the rear end regulating member 33 to the upper surface of the slide cassette 71.

  In the paper feed cassette 81 of this embodiment, in order to position the paper P, the rear end in the paper feed direction D1 of the paper P stored in the paper storage unit 35 by the rear end regulating member 33 (upstream of the paper feed direction D1). Side edges) are aligned, and positioning in the width direction E of the paper P is performed by the width alignment cursor pairs 34a and 34b.

  As shown in FIGS. 2 to 5, the base cassette 82 is a tray having a paper storage unit 35 that can store paper P in a stacked state. In the base cassette 82, an opening 82c is formed at the upstream end 35a in the paper feeding direction D1 in the paper storage unit 35. Since the upstream end portion of the base cassette 82 has no wall and an opening 82c is formed, the sheet storage portion 35 is opened to the outside through the opening 82c.

  Further, as shown in FIG. 5, a guide groove 74 extending in the paper feeding direction D1 from the upstream end 82b is formed in the bottom wall 82a of the base cassette 82. The guide groove 74 has guide walls 74a and 74b parallel to each other on both sides thereof.

  A slit 75 is formed at the bottom of the guide groove 74 of the bottom wall 82a. Similarly to the guide groove 74, the slit 75 extends in the paper feeding direction D1.

  Further, a through hole 73 is formed in the vicinity of the opening 82c of the base cassette 82 and at a position slightly downstream of the upstream end portion 82b in the sheet feeding direction D1 of the bottom wall 82a.

  As shown in FIGS. 5 and 10, a communication space 82 e for communicating the through hole 73 and the guide groove 74 is formed on the lower surface side of the bottom wall 82 a. Since the communication space 82e is opened on the upstream side in the paper feeding direction D1, the support portion 76 (see FIG. 6) on the slide cassette 71 side can be inserted.

  The base cassette 82 has a cassette cover 43 on the downstream end side in the paper feeding direction D1. The surface of the cassette cover 43 is exposed to the outside and constitutes a part of the exterior surface of the image forming apparatus 1.

  The slide cassette 71 has a first position I where the upstream end 71c of the slide cassette 71 is stored in the paper storage section 35 and the upstream end 71c through the opening 82c in a direction D2 opposite to the paper feeding direction D1. The base cassette 82 is slidably attached to the inside of the guide groove 74 of the base cassette 82 so that the base cassette 82 can move between the second position II protruding outward. The slide cassette 71 is provided so as to be capable of reciprocating along the guide walls 74a and 74b of the guide groove 74 in the paper feeding direction D1 and the opposite direction D2 in FIG.

  As shown in FIG. 6, on the upper surface of the slide cassette 71, a rack portion 78 in which a plurality of teeth 77 are arranged along the paper feeding direction D1 is formed. The rack portion 78 has a jagged surface by continuously arranging triangular prism-shaped teeth 77 in the paper feeding direction D1. On both sides of the rack portion 78, rail portions 71d extending in parallel with the rack portion 78 are provided. The rail portion 71d is composed of a rib or the like protruding from the upper surface of the slide cassette 71.

  On the lower surface 71b of the slide cassette 71, as shown in FIG. 9, an engagement protrusion 86 of a second fixing portion 92 described later is formed.

  Further, on the side surface of the slide cassette 71, a support portion 76 and an operation button 72 of the first fixing portion 91 described later are integrally formed.

As shown in FIGS. 7 to 8, the rear end regulating member 33 is provided on the upper surface of the slide cassette 71, and the rear end in the paper feeding direction D <b> 1 of the paper P stored in the paper feeding cassette 81 (that is, the paper feeding direction). D1 upstream end) is regulated. The rear end regulating member 33 includes a pedestal portion 33a extending in parallel with the slide cassette 71, a pressing plate 33b rising from the upstream end portion of the pedestal portion 33a, and a meshing portion 33c provided on the lower surface of the pedestal portion 33a. Have. The pressing plate 33b abuts on the rear end of the paper P and restricts the movement of the paper P in the direction D2 opposite to the paper feeding direction D1. The meshing portion 33 c has teeth 33 d that mesh with the teeth 77 of the rack portion 78 of the slide cassette 71. It can be slid along and positioned at a desired position.

  The first fixing portion 91 positions and fixes the slide cassette 71 at the first position I. As illustrated in FIGS. 3 to 6, the first fixing portion 91 includes a support portion 76, an operation button 72, and a through hole 73.

  The support portion 76 shown in FIG. 6 protrudes in the width direction of the slide cassette 71 from the upstream end portion or the vicinity thereof in the paper feeding direction D1 in the slide cassette 71. The support portion 76 is a thin tongue-like member made of synthetic resin or the like, and can be easily bent and deformed. The base end portion 76 b of the support portion 76 is connected to the side wall of the slide cassette 71.

  The operation button 72 shown in FIG. 6 is provided on the top surface of the distal end side end portion 76 a of the support portion 76. The operation button 72 corresponds to the convex portion of the present invention. For example, the operation button 72 is integrally formed of synthetic resin together with the slide cassette 71 and the support portion 76. The operation button 72 may be manufactured by a member different from the slide cassette 71 and the support portion 76.

  The operation button 72 of the present embodiment is formed of a cylindrical protrusion. On the side of the paper feeding direction D1 above the operation button 72, a slope 72a is formed that inclines in a direction that decreases in the paper feeding direction D.

  The through hole 73 is formed in the bottom wall 82 a near the opening 82 c of the base cassette 82. The through hole 73 has a circular shape that can be engaged with the columnar operation button 72.

In the first fixing portion 91, as shown in FIG. 3, when the slide cassette 71 is in the first position I, the operation button 72 is exposed with the upper end portion of the operation button 72 exposed upward through the through hole 73. Engages with the through-hole 73 and, as shown in FIG. 4, when the slide cassette 71 is in the second position II, the operation button 72 is separated from the base cassette 82. In other words, the first fixing portion 91 has a first posture in which the operation button 72 and the through-hole 73 are engaged with the upper end portion of the operation button 72 exposed upward through the through-hole 73 (FIGS. 3 and 10 to 11). And a second posture (see FIGS. 4 and 12) in which the support portion 76 is deformed when the user presses the upper end portion of the operation button 72 and the engagement between the operation button 72 and the through hole 73 is released. ) Can be changed. When the slide cassette 71 is in the first position, the first fixed portion 91 is in the first posture, and when the slide cassette 71 is moved from the first position to the second position, the first fixed portion 91 is in the second posture. And the user is allowed to hold the operation button 72 and pull the slide cassette 71 to the second position.

  As shown in FIGS. 12 to 13, the second fixing portion 92 positions and fixes the slide cassette 71 at the second position II. The second fixing portion 92 is disposed farther from the first fixing portion 91 (the operation button 72, the through hole 73, etc.) than the first fixing portion 91 (on the paper feeding direction D1 side) of the paper storage portion 35 of the base cassette 82. Has been. Therefore, the structure of the 1st fixing | fixed part 91 and its vicinity can be simplified.

  The second fixing portion 92 of the present embodiment includes a downstream end portion 71 a of the slide cassette 71, an engagement protrusion 86 provided on the lower surface side of the slide cassette 71, and a stopper 87 provided on the upper surface side of the base cassette 82. And an upstream edge 75b of the slit 75 formed in the bottom wall 82a of the base cassette 82.

  As shown in FIG. 9, the engagement protrusion 86 is formed on the lower surface 71 b of the slide cassette 71. As shown in FIG. 10, the engagement protrusion 86 is inserted into the slit 75 of the base cassette 82, and the stroke of the slide cassette 71 is moved by a predetermined distance (specifically, the length of the slit 75 determines the engagement protrusion 86. The length is subtracted).

  A slope 86a is formed on the downstream side of the engaging protrusion 86 in the paper feeding direction D1, and is inclined upward as it goes in the paper feeding direction D1. Therefore, when attaching the slide cassette 71 to the base cassette 82, the inclined surface 86 a can easily ride on the bottom wall 82 a of the base cassette 82, and the engaging protrusion 86 can be easily inserted into the slit 75.

  A standing wall portion 86b that rises perpendicularly to the upstream side is formed on the downstream side of the engaging projection 86 in the paper feeding direction D1. When the standing wall portion 86b hits the upstream end edge 75b of the slit 75, the slide cassette 71 is restricted at the second position II so that the slide cassette 71 cannot move further outward.

  As shown in FIG. 12, the stopper 87 is in the vicinity of the slit 75 on the upper surface of the bottom wall 82 a of the base cassette 82, and when the slide cassette 71 is in the second position II, the downstream end of the slide cassette 71. It arrange | positions in the position engaged with the part 71a. The stopper 87 is formed of a triangular or trapezoidal thin plate-like protrusion.

  The height of the stopper 87 is such that the slide cassette 71 is downstream of the slide cassette 71 with such a locking force that the slide cassette 71 does not shift in the paper feeding direction D1 (that is, the direction toward the first position I) while the image forming apparatus 1 is being used. When the slide cassette 71 slides in the paper feeding direction D1 or in the opposite direction, the stopper 87 comes into contact with the lower surface 71b of the slide cassette 71 so that it can slide. It is set below the height that does not cause an obstacle.

  Further, as shown in FIG. 3, the paper feed cassette 81 of the present embodiment includes a width alignment cursor pair 34 a and 34 b. The width alignment cursor pairs 34a and 34b are provided so as to be able to reciprocate in the paper width direction (the direction of arrow E in FIG. 3) along the guide rail 82d. The sheet bundle S can be stored at a predetermined position in the sheet feeding unit 19 by moving the width alignment cursor pairs 34a and 34b and the trailing edge regulating member 33 according to the sheet size to be stacked.

  In addition, as shown in FIGS. 2 to 3, the paper feed cassette 81 according to the present embodiment includes an elevating plate 61 on which a sheet bundle S composed of a plurality of sheets P is stacked inside the sheet storage unit 35. An upstream end 61a (left end in FIG. 2) in the paper feeding direction D1 of the elevating plate 61 is rotatably supported inside the paper storage unit 35. The elevating plate 61 can turn in the vertical direction inside the paper storage unit 35 with the upstream end 61a as the center of rotation.

  A drive shaft 36 and a push-up member 62 are provided as an elevating mechanism for elevating the elevating plate 61 below the end 61b in the sheet feeding direction D1 of the elevating plate 61, and power of a motor (not shown) is supplied to the drive shaft. By applying to 36, the elevating plate 61 can be moved up and down via the push-up member 62 and displaced between the paper feeding position and the retracted position.

  As shown in FIG. 2, the paper feeding unit 19 includes a paper feeding roller 411 provided on the downstream side in the transport direction of the pickup roller 20 and a separating roller 421 provided below the paper feeding roller 411. Yes. Furthermore, a transport roller 37 is provided on the downstream side in the transport direction of the pickup roller 20 and the paper feed roller 411.

  The paper feed roller 411 feeds the paper P taken out by the pickup roller 20 to the transport roller 37. The paper feed roller 411 rotates in the direction in which the paper P can be transported downstream, whereas the roller 421 rotates in the direction in which the paper P is sent back upstream. Even if several sheets of paper P taken out by the pickup roller 20 are overlapped with each other, it is possible to prevent the paper other than the uppermost sheet P from being fed in the direction of the transport roller 37. Only the paper P is transported to the transport roller 37 by the paper feed roller 411.

(Description of the state in which the slide cassette 71 is in the first position I)
In the sheet feeding unit 19 of the present embodiment configured as described above, as shown in FIGS. 3 and 10 to 11, the first position I in which the slide cassette 71 is stored in the sheet storage unit 35 of the base cassette 82. The slide cassette 71 is fixed at the first position I by the first fixing portion 91 in the first posture . That is, the operation button 72 provided on the slide cassette 71 is fitted into the through hole 73 formed in the bottom wall 82a of the base cassette 82, whereby the slide cassette 71 can be fixed at the first position I.

  In this state, the support portion 76 that connects the operation button 72 and the slide cassette 71 is inserted into the communication space 82e (see FIG. 10) on the lower surface side of the bottom wall 82a of the base cassette 82.

(Explanation of the case where the slide cassette 71 moves to the second position II)
On the other hand, as shown in FIGS. 12 to 13, when moving the slide cassette 71 from the opening 82 c of the base cassette 82 to the second position II protruding outward from the base cassette 82, the user or the like first operates The button 72 is pushed down with the thumb, the fitting between the operation button 72 and the through hole 73 is released, and the first fixing portion 91 is brought into the second posture. Thereafter, by pulling the operation button 72 protruding below the base cassette 82 outward with an index finger or the like, the slide cassette 82 is pulled out in the direction D2 opposite to the paper feeding direction D1 and moved to the second position II. Accordingly, the slide cassette 82 can be moved to the second position II simply by pushing the operation button 72 with the thumb and pulling the operation button 72 outward with an index finger or the like, so that the operation is simple.

  When the slide cassette 71 reaches the second position II, the slide cassette 71 is fixed to the second position II by the second fixing portion 92. That is, when the upright wall portion 86b of the engaging projection 86 provided on the lower surface 71b of the slide cassette 71 and the upstream end portion 75b of the slit 75 formed in the bottom wall 82a of the base cassette 82 are engaged, the slide cassette The movement to the direction D2 which goes to the outward of 71 is controlled. At the same time, the downstream end 71a of the slide cassette 71 and the stopper 87 provided on the upper surface of the bottom wall 82a of the base cassette 82 are engaged to restrict the movement of the slide cassette 71 in the paper feeding direction D1. . As a result, the slide cassette 71 cannot move in either the paper feeding direction D1 or the opposite direction D2, and is fixed at the second position II. In this state, the space for storing the paper P in the paper feed cassette 81 is expanded, so that a large paper size can be stored.

(Features of this embodiment)
(1)
In the paper feeding unit 19 in the above embodiment, an opening 82c is formed at the upstream end 35a in the paper feeding direction D1 in the paper storage portion 35 of the base cassette 82, and the upstream end 71c of the slide cassette 71 is formed. A first fixing portion 91 for positioning and fixing the slide cassette 71 is provided at a first position I stored in the base cassette 82. The first fixing portion 91 includes a support portion 76 that protrudes in the width direction E of the slide cassette 71, an operation button 72 provided on the upper surface of the tip end portion 76 a of the support portion 76, and an opening portion of the base cassette 82. The through-hole 73 is formed in the bottom wall 82a near 82c. The operation button 72 engages with the through hole 73 on the base cassette 82 side when the slide cassette 71 is in the first position I. Since the upper end portion of the operation button 72 at this time is exposed upward through the through hole 73, it can be pressed by a user's finger or the like. On the other hand, when the slide cassette 71 is positioned at the second position II where the upstream end 71c of the slide cassette 71 protrudes outward from the opening 82c of the base cassette 82, the operation button 72 is moved to the base cassette. Separated from 82. This eliminates the need for a through-hole or the like that engages at the second position II on the base cassette 82 side, so that the structure can be simplified and the strength can be ensured, so that the base cassette 82 can be downsized.

(2)
The first fixing portion 91 is formed on the bottom wall 82a near the opening 82c of the base cassette 82 as an engaged portion that engages with the operation button 72 provided on the slide cassette 71 side. It has a through-hole 73 that can be engaged. Thus, when the slide cassette 71 is in the first position I, the first fixing portion 91 is engaged with the operation button 72 in the through hole 73 with the upper end portion of the operation button 72 exposed upward through the through hole 73. Take the first posture. At this time, since the operation button 72 pressed by the user's finger or the like is located near the opening 82c of the base cassette 82, the operation button 72 is pressed to easily engage the operation button 72 and the through hole 73. The slide cassette 71 can be easily pulled out.

  In addition, since the operation button 72 is connected to the slide cassette 71 via the support portion 76, the operation button 72 is separated from the slide cassette 71 in the width direction E. Therefore, the user can easily operate the operation button 72 without being obstructed by the slide cassette 71 or the rear end regulating member 33.

(3)
Further, when the slide cassette 71 is located at the second position II projecting outward from the opening 82c of the base cassette 82, the operation button 72 is separated from the base cassette 82. When returning from the second position II to the first position I, it is only necessary to push the slide cassette 71 back to the first position I, and the pressing operation of the operation button 72 is unnecessary. At this time, the operation button 72 descends to the lower side of the bottom wall 82 a of the base cassette 82 along the inclined surface 72 a, and is then pushed back upward by the elastic force of the support portion 76 and fitted into the through hole 73.

(4)
When the slide cassette 71 moves from the first position to the second position, the support portion 76 is deformed when the upper end portion of the operation button 72 is pressed by the user and the first fixing portion 91 penetrates the operation button 72. A second posture is adopted in which the engagement with the hole 73 is released. In the second posture, since the user is allowed to pull out the slide cassette 71 to the second position by holding the operation button 72, the operation is simple. Further, since only the rear end regulating member 33 provided on the upper surface of the slide cassette 71 is located at the upstream end in the paper feeding direction D1 in the opening 82c of the base cassette 82, the rear end regulating member 33 is gripped and slid. It is possible to easily move the cassette 71 to the second position II.

(5)
Further, in the sheet feeding unit 19 of the above-described embodiment, the operation button 72 is formed of a cylindrical protrusion, and the through hole 73 that fits into the operation button 72 has a shape that can be engaged with the operation button 72. 71 can be positioned in all in-plane directions and swiveling directions of the slide cassette 71. By fitting the operation button 72 and the through-hole 73 of the first fixing portion 91, the slide cassette 71 can be positioned in the first direction. Generation of play in all in-plane directions and turning directions can be prevented when the position I is fixed.

  Further, since the operation buttons 72 and the through holes 73 look circular when viewed from above, the operation buttons 72 are easily seen by the inside of the paper storage unit 35 of the base cassette 82.

  Note that the operation buttons 72 are preferably colored in a color different from the colors of the slide cassette 71 and the base cassette 82 in order to make it easy to visually recognize.

(6)
Since the paper feed unit 19 of the above embodiment includes the second fixing portion 92, the slide cassette 71 can be reliably positioned and fixed at the second position II by the second fixing portion 92. In addition, it is possible to install a second fixing portion 92 that positions and fixes the slide cassette 71 at the second position II at a position away from the first fixing portion 91, thereby simplifying the first fixing portion 91 and It becomes possible to reduce the size.

  Further, when the slide cassette 71 is at the second position II, the slide cassette 71 is reliably held at the second position II even if the rear end regulating member 33 is moved on the slide cassette 71.

(7)
Since the image forming apparatus 1 of the present embodiment includes the paper feeding unit 19 as described above, the cassette size can be easily expanded and contracted while the apparatus is downsized with a simple configuration.

(Modification)
(A)
In the above embodiment, the cylindrical operation button 72 has been described as an example of the operation button. However, the present invention is not limited to this, and a convex portion having another shape may be used as the operation button. . For example, even in the case of the operation button 72 having a polygonal column shape, when the slide cassette 71 is fixed at the first position I by fitting with the corresponding through-hole 73, the in-plane direction and the turning direction are all It is possible to prevent the occurrence of backlash, and it is easy to visually recognize inside the paper storage portion 35 of the base cassette 82. It is also possible to employ an operation button 72 having a shape other than a cylinder or a polygonal column.

(B)
In order to further facilitate the movement of the slide cassette 71 from the first position I to the second position II, an elastic member such as a spring for pushing the slide cassette 71 to the second position II is used as the guide groove 74 of the base cassette 82 or the like. The slide cassette 71 may be provided. In that case, when the slide cassette 71 is in the first position I, the slide cassette 71 is automatically removed from the base cassette 82 by the elastic force of the elastic member simply by pressing the operation button 72 and releasing the engagement with the through hole 73. It is possible to jump out and move toward the second position II.

(C)
In the above embodiment, the image forming apparatus including the sheet feeding unit, which is an embodiment of the sheet feeding apparatus of the present invention, has been described as an example. However, the present invention is not limited to this, Other apparatuses such as a reading apparatus can also include the sheet feeding apparatus of the present invention.

(D)
In the above-described embodiment, the sheet is described as an example of the sheet conveyed by the sheet feeding unit which is an embodiment of the sheet feeding apparatus. However, the present invention is not limited to this. Any sheet-like material that can be conveyed is included in the concept of “sheet” conveyed by the sheet feeding apparatus of the present invention.

19 Paper Feed Unit (Sheet Feeder)
33 Rear end regulating member 71 Slide cassette 71a Downstream end 72 Operation button (convex)
75 slit 75 b upstream edge 81 paper feed cassette 82 base cassette 82 c opening 86 engaging protrusion 87 stopper 91 first fixing part 92 second fixing part 93 image forming part 100 image forming apparatus

Claims (4)

A sheet feeding device that includes a feeding cassette that stores sheets, and that feeds sheets from the feeding cassette,
The feeding cassette is
Accommodating the sheets in a stacked state, a base cassette having an opening at the upstream end of the feeding direction of the sheet,
A slide cassette that is slidably attached to the base cassette , wherein an upstream end of the slide cassette is stored in the base cassette and an upstream end of the slide cassette passes through the opening. A slide cassette movable between a second position protruding outward;
A rear end regulating member that is provided on an upper surface of the slide cassette and regulates a rear end of the sheet stored in the base cassette in the feeding direction;
A first fixing portion for positioning and fixing the slide cassette at the first position;
The first fixing part is
A support portion projecting in the width direction of the slide cassette from an upstream end portion or the vicinity thereof in the slide cassette in the feeding direction;
A convex portion provided on the supporting part,
Formed in the bottom wall near the opening of the base cassette, and having a through hole engageable with the convex portion;
The first fixing portion includes a first posture in which the convex portion and the through hole engage with each other in a state where the upper end portion of the convex portion is exposed upward through the through hole, and the upper end portion of the convex portion is determined by a user. The support portion is deformed by being pressed, and the posture can be changed between the second posture in which the engagement between the convex portion and the through hole is released,
When the slide cassette is in the first position, the first fixing portion is in the first posture,
When the slide cassette moves from the first position to the second position, the first fixed portion takes a second posture, and the user holds the convex portion and holds the slide cassette in the second position. Allow to pull out to the position,
When the slide cassette is in the second position, the convex portion is separated from the base cassette.
A sheet feeding apparatus characterized by that. The convex portion is composed of a columnar or polygonal columnar projection,
The sheet feeding apparatus according to claim 1. A second fixing portion for positioning and fixing the slide cassette at the second position;
The sheet feeding apparatus according to claim 1 or 2. A sheet feeding apparatus according to any one of claims 1 to 3,
An image forming unit that forms an image on a sheet fed by the sheet feeding device;
An image forming apparatus.

Images