JP5414591B2 - Paper feeding device and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a paper feeding device that feeds paper in a predetermined direction, and an image forming apparatus including the paper feeding device.

  An image forming apparatus such as a copying machine, a printer, or a facsimile includes an image forming unit that forms a toner image on a sheet, and a sheet feeding device that feeds the sheet to the image forming unit.

  For example, as shown in Patent Document 1, a paper feeding device includes a paper cassette that stores paper, a pickup roller that picks up paper one by one from the paper cassette, a paper feeding roller that feeds paper to an image forming unit, and a paper feeding roller. A retard roller that is opposed to the paper roller and prevents double feeding of the paper is included as a main component.

JP 2000-267372 A

  In the paper feeder disclosed in Patent Document 1, the insertion direction in which the paper cassette is inserted into the housing of the image forming apparatus and the direction in which the pickup roller takes out the paper from the paper cassette are configured to be the same. In such a configuration, when the paper cassette is strongly inserted into the housing, the paper is ejected from the paper cassette and scattered on the downstream side when viewed from the insertion direction of the paper cassette, that is, in the vicinity of the pickup roller. There is. In that case, since the pickup roller cannot properly take out the paper from the paper cassette, the feeding operation is delayed.

  Accordingly, in view of the above circumstances, the present invention provides a paper feeding device capable of smoothly performing a feeding operation by preventing paper scattering when the paper cassette is inserted into the housing, and an image forming apparatus including the paper feeding device. An object is to provide an apparatus.

To achieve the above object, the sheet feeding apparatus according to the present invention comprises a housing, a paper cassette having a sheet accommodating space for accommodating the paper, it is insertable in the housing toward the first direction the first direction is located on the downstream side, the a paper cassette having a downstream wall forming the paper accommodating section, the paper feed mechanism for feeding removed along the paper from the paper cassette to said first direction A main body provided on the downstream side in the first direction from the downstream side wall , and the paper cassette of the paper that extends from the main body and is received in the paper storage space. and a sheet scattering prevention member having a restricting surface for the return contact with the paper only paper downstream wall beyond when you jump out from the paper cassette into the paper cassette when inserted , The regulations Surface has a first surface that protrudes at a position higher than the downstream wall, and a second surface that protrudes extending from an upper portion of the first surface above the paper storage space.

  According to the paper feeding device of the present invention, the first surface of the regulation surface protrudes to a position higher than the downstream side wall portion, and therefore when viewed from the first direction, which is the insertion direction of the paper cassette into the housing. It is a surface that obstructs the first direction. Further, since the second surface of the regulating surface protrudes above the paper accommodation space, it is a surface that faces the surface of the paper from above when the paper cassette is inserted into the housing. Therefore, the first surface and the second surface of the regulation surface can come into contact with a sheet that is about to jump out of the sheet cassette beyond the downstream side wall portion of the sheet cassette when the sheet cassette is inserted into the housing. As a result, the sheet is returned to the sheet cassette, and scattering of the sheet is prevented. As a result, the feeding operation by the paper feeding mechanism can be performed smoothly.

  In a preferred embodiment of the present invention, the first surface is an inclined surface that extends beyond the downstream side wall and extends upward of the sheet accommodation space.

  According to this configuration, compared to a configuration that simply extends linearly upward so that the first surface protrudes to a position higher than the downstream side wall portion, the sheet that is in contact with the first surface is reliably placed in the sheet cassette. Can be returned.

  In another preferred embodiment of the present invention, a pair of the paper scattering preventing members are arranged in an orthogonal direction orthogonal to the first direction.

  According to this structure, compared with the structure using the single sheet | seat scattering prevention member, a sheet | seat can be more reliably returned in a sheet cassette.

  In still another preferred embodiment of the present invention, the sheet has a width dimension in the orthogonal direction, and the interval between the sheet scattering preventing members is set to correspond to a minimum width dimension.

  According to this configuration, a sheet having a minimum width dimension to a sheet having the maximum width dimension can be returned to the sheet cassette.

  In another preferred embodiment of the present invention, when the sheet cassette is inserted into the housing, the sheet scattering preventing member protrudes to a position where the first surface is higher than the downstream side wall, and the first When the sheet feeding mechanism feeds the sheet, the first surface is retracted from above the downstream side wall and the second surface is in a first posture in which two surfaces protrude above the sheet storage space. The surface takes a second posture of retreating from above the sheet accommodation space.

  According to this configuration, since the paper scattering preventing member takes the first posture when the paper cassette is inserted into the housing, the paper to be ejected can be returned into the paper cassette. Further, when the paper feeding mechanism feeds the paper, the paper scattering preventing member takes a second posture in which the first surface is retracted from above the downstream side wall and the second surface is retracted from above the paper accommodating space. Therefore, the paper feeding operation of the paper feeding mechanism is not hindered.

  The image forming apparatus according to the present invention includes: an image forming unit that forms a toner image on a sheet; and a sheet feeding device that feeds the sheet to the image forming unit. Is used.

  According to the sheet feeding device and the image forming apparatus including the sheet feeding device according to the present invention, in view of the above circumstances, even when the sheet cassette is strongly inserted into the housing, the sheet is prevented from being scattered and fed. The operation can be performed smoothly.

1A and 1B are perspective views of a printer according to an embodiment of the present invention, in which FIG. 1A shows a state in which a paper cassette is completely accommodated in a printer casing, and FIG. (C) shows a state in which a part of the paper cassette is inserted into the housing. It is a figure which shows the internal structure of the printer shown by FIG. FIG. 6 is a perspective view of the paper feeding device viewed from the back wall side of the paper cassette, and shows the standing posture of the paper scattering prevention member. FIG. 6 is a perspective view of the sheet feeding device as viewed from above the sheet cassette, and shows a standing posture of the sheet scattering preventing member. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 3 and shows a standing posture of the paper scattering preventing member. FIG. 6 is a cross-sectional view illustrating a lying posture of a paper scattering preventing member. FIG. 6 is a perspective view of the paper feeding device as viewed from above the paper cassette, showing the lying posture of the paper scattering prevention member. It is a side view of a paper scattering prevention member. It is a perspective view of a paper scattering prevention member.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that terms used in the following description, such as “up”, “down”, “left”, “right” and the like, are merely for the purpose of clarifying the explanation and do not limit the present invention. Not what you want. The term “paper” used in the following description generally means printing paper subjected to printing processing, but the present invention is not limited to this, and tracing paper, OHP sheet, cardboard And other sheets on which image formation can be applied.

  1A and 1B are external perspective views of an image forming apparatus according to an embodiment of the present invention, in which FIG. 1A shows a state in which a paper cassette is completely accommodated in the image forming apparatus, and FIG. Shows a state of being pulled out from the image forming apparatus, and (c) shows a state in which a part of the paper cassette is inserted into the image forming apparatus. The image forming apparatus shown in FIG. 1 is a printer, but the present invention is not limited to this. The image forming apparatus may be a copier, a facsimile machine, or another apparatus capable of forming an image on paper. It may be used as

  The printer 1 includes a substantially rectangular parallelepiped housing 2 as a whole. The housing 2 includes a front wall 21 in which a substantially rectangular opening 211 serving as an insertion port for the paper cassette 3 is formed, a rear wall 22 at a position facing the front wall 21, and the front wall 21 and the rear wall 22. And a right side wall 23 and a left side wall 24 that form the side surface of the printer 1, and a top wall 25 that extends between the front wall 21 and the back wall 22 and forms the upper surface of the printer 1.

  A substantially rectangular parallelepiped-shaped accommodation space extends from the opening 211 of the front wall 21 toward the back wall 22. The outer peripheral contour of the paper cassette 3 has a shape complementary to this accommodation space. The paper cassette 3 is movable from the front wall 21 side toward the back wall 22. It is also possible to pull out the paper cassette 3 from the housing 2 by pulling the paper cassette 3 from the back wall 22 toward the front wall 21. Thus, the paper cassette 3 is formed so as to be capable of reciprocating within the accommodation space.

  Various devices for demonstrating the functions of the printer 1 are disposed in the housing 2. The right side wall 23 is formed with a heat radiating port 231 for releasing heat generated from these devices. A concave space 251 that narrows toward the front wall 21 is formed on the top wall 25, and a base end portion of the concave space 251 located on the back wall 22 side is formed by the discharge wall 252. The discharge wall 252 is formed with a discharge port 253 for discharging the image-formed paper. The sheets subjected to the image forming process are discharged from the discharge port 253 and stacked in the concave space 251 on the top wall 25.

  When the paper cassette 3 is completely pushed into the housing 2, the paper cassette 3 faces the front wall 31 that forms the front side wall surface of the printer 1 together with the front wall 21 of the housing 2 and the front wall 31. The rear wall 32 (downstream side wall) located at the position, the right side wall 33 and the left side wall 34 that extend between the front wall 31 and the rear wall 32 and form the side surface of the paper cassette 3, and the front wall 31 and the rear wall 32. And a bottom wall 35 that forms the bottom surface of the paper cassette 3.

  The top surface of the bottom wall 35 of the paper cassette 3 can be reciprocated on a straight line connecting the left and right side walls 33 and 34 with a first adjustment knob 36 that can reciprocate on a straight line from the front wall 31 to the back wall 32. A pair of second adjustment knobs 37 are erected. The first adjustment knob 36 and the second adjustment knob 37 are positioned so as to come into contact with the side surface (the surface formed by stacking the edges of the stacked sheets) stored in the sheet cassette 3. An accommodation space 38 for accommodating paper is formed by the first adjustment knob 36, the pair of second adjustment knobs 37, and the inner surface of the back wall 32.

  FIG. 2 schematically shows the internal structure of the printer 1 shown in FIG. The internal structure of the printer 1 will be described with reference to FIG. 1 in conjunction with FIG. The printer 1 is connected to a personal computer (PC) (not shown) or the like directly or via a LAN. An external device such as a personal computer transmits image data to the printer 1. In addition to the components described below with reference to FIG. 2, the printer 1 also includes other components provided in a general printer, such as a control circuit that controls the operation of the printer 1. Yes.

  As shown in FIG. 2, an intermediate transfer unit 92, an image forming unit 93, an exposure unit 94, a fixing unit 97, a paper discharge roller pair 96, and a paper feeding device 4 are provided inside the housing 2.

  The image forming unit 93 includes a photoreceptor drum 931 (a photoreceptor on which a latent image is formed by an electrophotographic method) that carries toner images of yellow, magenta, cyan, and black. As the photosensitive drum 931, a photosensitive drum using an amorphous silicon (a-Si) material can be used.

  Around the photosensitive drum 931, a charger 933, a developing device 910 (910Y, 910M, 910C, 910K), a transfer roller 932, a cleaning device 934, and the like are arranged. The charger 933 uniformly charges the surface of the photosensitive drum 931. The surface of the charged photosensitive drum 931 is exposed by the exposure unit 94 to form an electrostatic latent image. The developing devices 910Y, 910M, 910C, and 910K develop the electrostatic latent images formed on the respective photosensitive drums 931 using the toners of the respective colors supplied from the toner containers 900Y, 900M, 900C, and 900K, respectively ( Visualization). The transfer roller 932 forms a nip portion with the photosensitive drum 931 across the intermediate transfer belt 921, and primarily transfers the toner image on the photosensitive drum 931 onto the intermediate transfer belt 921. The cleaning device 934 cleans the peripheral surface of the photosensitive drum 931 after the toner image is transferred.

  Each of the developing devices 910Y, 910M, 910C, and 910K includes a housing 911, and the housing 911 stores a two-component developer having a magnetic carrier and toner. In the housing 911, two stirring rollers 912 and 913 are rotatably arranged. The two stirring rollers 912 and 913 extend in parallel with each other near the bottom of the housing 911.

  A developer circulation path is formed on the inner bottom surface of the housing 911. The stirring rollers 912 and 913 are disposed in the circulation path. A partition wall 914 erected from the bottom of the casing 911 extends in the axial direction of the stirring rollers 912 and 913 between the stirring rollers 912 and 913. The partition wall 914 defines a circulation path. A circulation path is formed so as to go around the partition wall 914. The two-component developer is charged while being stirred and conveyed by the stirring rollers 912 and 913 through this circulation path.

  The two-component developer circulates in the housing 911 while being stirred by the stirring rollers 912 and 913, the toner is charged, and the two-component developer on the stirring roller 912 is attracted to the magnetic roller 915 located on the upper side. Are transported. The sucked two-component developer forms a magnetic brush on the magnetic roller 915. The layer thickness of the magnetic brush is regulated by a doctor blade 916. The toner layer on the developing roller 917 is formed by a potential difference between the magnetic roller 915 and the developing roller 917, and the electrostatic latent image on the photosensitive drum 931 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. Irradiation with light based on the transmitted image data forms an electrostatic latent image.

  The intermediate transfer unit 92 includes an intermediate transfer belt 921, a driving roller 922, and a driven roller 923. To the intermediate transfer belt 921, the toner images are primarily transferred from the plurality of photosensitive drums 931, and the images from the respective photosensitive drums 931 are overcoated. The intermediate transfer belt 921 secondarily transfers this overcoated toner image onto a sheet S supplied from a sheet feeding device 4 to be described later in the secondary transfer unit 980. 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 casing 2 of the printer 1. In this embodiment, the image forming unit 93, the intermediate transfer unit 92, and the secondary transfer unit 980 constitute an image forming unit that forms a toner image on the paper S.

  The fixing unit 97 performs a fixing process on the toner image on the sheet S secondarily transferred from the intermediate transfer unit 92. The sheet S with the color image that has undergone the fixing process is discharged toward a discharge roller pair 96 formed in the upper part of the internal space of the housing 2. The paper discharge roller pair 96 discharges the paper S conveyed from the fixing unit 97 into the concave space 251 through the discharge port 253 formed in the discharge wall 252 (see FIG. 1).

  The paper feeding device 4 is a device for feeding the paper S to the secondary transfer unit 980, and includes a paper cassette 3, a paper feeding mechanism 40, and a housing that houses the paper cassette 3 and the paper feeding mechanism 40. It consists of a body 2.

  The sheet cassette 3 has the structure described with reference to FIG. 1 and includes a lift plate 381 on which a sheet bundle T composed of a plurality of sheets S is stacked in the sheet accommodation space 38. An upstream end (left end in the figure) of the lift plate 381 is rotatably supported by a support portion 382. The lift plate 381 is rotatable in the vertical direction with respect to the bottom wall 35 by the support portion 382 with the downstream end portion (the right end portion in FIG. 2) as a free end in the paper storage space 38. The support portion 382 is provided on the left and right side walls 33 and 34 (see FIG. 1) that are opposed to each other in the width direction of the paper S.

  Below the downstream end of the lift plate 381, a drive shaft 383 and a push-up member 384 are provided as a lift mechanism that lifts and lowers the lift plate 381. The drive shaft 383 is connected to a drive motor (not shown). When the drive motor operates under the control of the control unit that controls the overall operation of the printer 1, the drive shaft 383 rotates, the tip of the push-up member 384 connected to the lift plate 381 rises, and the lift plate 381 The downstream end rises.

  The paper feed mechanism 40 feeds the paper S from the paper cassette 3 to the secondary transfer unit 980 when the paper cassette 3 is completely inserted into the housing 2 and set at a predetermined paper feed position. Before the feeding operation of feeding the paper S by the paper feed mechanism 40 is performed, the lift plate 381 is set to the lifted position by raising the downstream end thereof by the lifting mechanism. Note that the downstream end of the lift plate 381 is set to a lowered position that is lowered when a new sheet bundle T is supplied.

  Specifically, the paper feed mechanism 40 is disposed between the back wall 32 of the paper cassette 3 inserted into the housing 2 of the printer 1 and the back wall 22 of the housing 2 of the printer 1. The mechanism is in pressure contact with the pickup roller 41 disposed above the downstream end of the lift plate 381, the paper feed roller 42 disposed on the downstream side of the pickup roller 41, and the paper feed roller 42. And a separation roller 43. A feeding path through which the sheet S is fed from the pickup roller 41 to the nip portion between the sheet feeding roller 42 and the separation roller 43 is set.

  When the paper cassette 3 is set at the paper feed position, the downstream end of the lift plate 381 rises, and the downstream end of the paper bundle T stacked on the lift plate 381 comes into contact with the pickup roller 41. When the pickup roller 41 rotates, the sheet S positioned at the top of the sheet bundle T on the lift plate 381 is taken out from the sheet cassette 3. The direction of taking out the paper S is a direction along the insertion direction A (first direction) of the paper cassette 3 into the housing 2 of the printer 1 (a direction from the front wall 21 toward the back wall 22).

  Thereafter, the paper S taken out from the paper cassette 3 is fed downstream by the paper feed roller 42. When a plurality of sheets S are simultaneously removed from the sheet cassette 3, the separation roller rotates in a direction to push the sheet S positioned below among the extracted sheets S to the sheet cassette 3. As a result, the sheets S are transported downstream one by one along the feeding path. In this way, the paper feed mechanism 40 feeds the paper S from the paper cassette 3 to the secondary transfer unit 980.

  A conveyance path extending toward the secondary transfer unit 980 positioned above the sheet feeding mechanism 40 is formed on the downstream side of the sheet feeding mechanism 40, and a pair of conveyance rollers 44 that convey the sheet S along the conveyance path. It is arranged. The paper S fed from the paper cassette 3 by the paper feed roller 42 is then transported to the secondary transfer unit 980 by the transport roller pair 44, and the toner image formed by the image forming unit 93 is transferred onto the paper S. The

  The paper feeding device 4 further includes a paper scattering preventing member 10. When the paper cassette 3 is inserted into the housing 2 and set at the paper feeding position, the paper S in the paper storage space 38 may jump out of the paper cassette 3 beyond the back wall 32 due to the impact. The paper scattering prevention member 10 is a member that comes into contact with the paper S about to jump out and returns the paper S to the paper cassette 3. The paper scattering preventing member 10 prevents the paper S from being scattered on the downstream side when viewed from the insertion direction A of the paper cassette 3, that is, below the pickup roller 41.

  The paper scattering preventing member 10 is configured to be switchable between an upright standing posture (first posture) and a lying down lying posture (second posture). The paper scattering preventing member 10 takes a standing posture when the paper cassette 3 is inserted into the housing 2, and takes a lying posture when the paper feeding mechanism 40 performs a feeding operation. 3 to 5 show the standing posture of the paper scattering preventing member 10, and FIGS. 6 and 7 show the lying posture of the paper scattering preventing member 10.

  First, the standing posture of the paper scattering preventing member 10 will be described with reference to FIGS. FIG. 3 is a perspective view of the paper feeding device 4 as viewed from the back wall 32 side of the paper cassette 3 and shows the standing posture of the paper scattering preventing member 10. FIG. 4 is a perspective view of the sheet feeding device 4 as viewed from above the sheet cassette 3, and shows the standing posture of the sheet scattering preventing member 10. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 3 and shows the upright posture of the paper scattering preventing member 10. In the illustrated embodiment, a pair of the paper scattering preventing members 10 are arranged and are separated from each other with a predetermined interval in the width direction of the paper S, that is, in the direction orthogonal to the insertion direction A of the paper cassette 3. Each sheet scattering prevention member 10 is a member disposed on the housing 2 side, and includes an elongated block-shaped main body portion 11 and a protruding portion 12.

  The elongated main body 11 has a shape extending along the back wall 32 of the paper cassette 3 when the paper scattering preventing member 10 is in the standing posture. As shown in FIG. 9 to be described later, lower ends of the adjacent elongated main body portions 11 are connected to each other by a connecting member 15. Further, the connecting member 15 is formed with a pair of swing shafts 16 protruding from both ends thereof in a direction orthogonal to the insertion direction A of the paper cassette 3. The paper scattering preventing member 10 is accommodated in a housing 45 (FIG. 7) disposed on the back wall 32 side of the paper cassette 3 in the housing 2 when in a second posture described later. The connecting member 15 and thus the pair of paper scattering preventing members 10 are rotatably supported by the housing 45 via the pair of swing shafts 16.

  As shown in FIG. 5, the protruding portion 12 is a portion that extends from the upper end of the elongated main body portion 11 to the upper side of the back wall 32 and protrudes above the sheet storage space 38 beyond the back wall 32. The protrusion 12 will be described in detail later.

  As is apparent from the above, the standing posture means that the elongated main body 11 of each paper scattering preventing member 10 stands along the back wall 32 and the projecting portion 12 passes over the back wall 32 and above the paper storage space 38. It is a state of being located.

  Next, the lying posture of the paper scattering preventing member 10 will be described with reference to FIGS. FIG. 6 is a cross-sectional view showing the lying posture of the paper scattering preventing member 10. FIG. 7 is a perspective view of the sheet feeding device 4 as viewed from above the sheet cassette 3, and shows the lying posture of the sheet scattering preventing member 10. A hook 13 is formed on the elongated main body 11 of one sheet scattering preventing member 10 on the surface opposite to the surface facing the back wall 32 in the standing posture. One end of a spring member 14 (biasing member) is locked to the hook 13. The other end of the spring member 14 is locked in place on the housing 45.

  The spring member 14 is positioned so as to bias the elongated body 11 and pull it downward. Therefore, the pair of paper scattering preventing members 10 rotate about the axis of the swing shaft 16 (FIGS. 3 and 9) in the clockwise direction in FIG. By this turning operation, the protruding portion 12 of each paper scattering preventing member 10 is retracted from above the back wall 32. Further, the protruding portion 12 is retracted so as to be out of the feeding path of the paper feeding mechanism 40. As shown in FIG. 7, the paper scattering preventing member 10 in which the elongated main body portion 11 is rotated and the protruding portion 12 is retracted is accommodated in a recess 46 formed in the housing 45.

  As is clear from the above, the lying posture is a state in which the protruding portion 12 is retracted from above the back wall 32, and the spring member 14 prevents the paper scattering so that the paper scattering preventing member 10 always takes the lying posture. The member 10 is biased.

  Switching between the standing posture and the lying posture of the paper scattering preventing member 10 uses a switching member. The switching member is composed of the rotating member 50 and the spring member 14 described above. The rotating member 50 is a member disposed on the outer wall surface of the back wall 32 of the paper cassette 3, and when the paper cassette 3 is inserted into the housing 2, the paper scattering preventing member 10 (actually, the connecting member Abuts against member 15).

  When the paper cassette 3 is inserted into the housing 2, the rotating member 50 contacts the paper scattering prevention member 10 along the insertion direction A of the paper cassette 3 so that the paper scattering prevention member 10 is shown in FIG. By rotating it counterclockwise around the axis of the swing shaft 16 from the state shown, the posture of the paper scattering preventing member 10 can be switched from the lying posture to the standing posture shown in FIG.

  As described above, the spring member 14 rotates the paper scattering preventing member 10 from the state shown in FIG. 5 in the clockwise direction around the pivot shaft 16, that is, in the direction opposite to the rotating member 50. Thus, the urging force is applied so that the paper scattering preventing member 10 always takes the lying posture shown in FIG. Therefore, the rotating member 50 needs to rotate the paper scattering preventing member 10 against the urging force of the spring member 14.

  Further, when the rotating member 50 is rotated in the clockwise direction from the state shown in FIG. 5 in which the rotating member 50 is in contact with the paper scattering preventing member 10, the contact state between the rotating member 50 and the paper scattering preventing member 10 is canceled. The anti-scattering member 10 is rotated clockwise by the spring member 14. Thereby, the paper scattering preventing member 10 is switched from the standing posture to the lying posture. A detailed description of the configuration of the rotating member 50 will be omitted because it is out of the spirit of the present invention.

  Hereinafter, the protrusion 12 of the paper scattering preventing member 10 will be described with reference to FIGS. 8 and 9 in addition to FIG. FIG. 8 is a side view of the paper scattering preventing member 10, and FIG. 9 is a perspective view of the paper scattering preventing member 10. The protruding portion 12 has a regulating surface 18 that comes into contact with the paper S about to jump out of the paper cassette 3 beyond the back wall 32. The restricting surface 18 includes a first surface 18a and a second surface 18b.

  The first surface 18a is a surface that protrudes to a position higher than the back wall 32 when the paper scattering preventing member 10 is in the standing posture. In the present embodiment, the first surface 18a passes through the back wall 32 and passes through the paper storage space. An inclined surface extending obliquely upward (upwardly left obliquely in FIG. 5) toward the upper side of 38. The first surface 18a is inclined at a predetermined angle α with respect to the horizontal plane. The first surface 18 a extends obliquely upward to the left while contacting the upper edge of the back wall 32 from the outer wall surface side of the back wall 32 when the paper scattering preventing member 10 is in the standing posture. Therefore, the first surface 18 a faces in the direction almost opposite to the insertion direction A of the paper cassette 3 and toward the paper storage space 38. Thus, the first surface 18 a is a surface that blocks the insertion direction A when the first surface 18 a is viewed from the insertion direction A of the paper cassette 3.

  The second surface 18 b is a surface that extends from the upper edge of the first surface 18 a in a substantially horizontal direction, that is, in a direction opposite to the insertion direction A of the paper cassette 3 and protrudes above the paper storage space 38. The protruding amount of the second surface 18b is set as appropriate. The second surface 18 b is a surface facing the surface of the paper S in the paper storage space 38 when the paper cassette 3 is inserted into the housing 2.

  As described above, a pair of the paper scattering preventing members 10 are arranged at a predetermined interval in the direction orthogonal to the insertion direction A of the paper cassette 3, that is, in the width direction of the paper S. The interval between the paper scattering preventing members 10, particularly the interval between the protrusions 12 having the regulating surfaces 18, is set to a predetermined value P as shown in FIG. The interval P is set to be substantially the same as or slightly smaller than the minimum width dimension in order to correspond to the sheet S having the smallest width dimension among the sheets S that can be stacked in the sheet cassette 3.

  When the paper scattering preventing member 10 is in the upright posture, the regulation surface 18 having the above-described configuration projects the first surface 18a to a position higher than the back wall 32, and the second surface 18b is located above the paper storage space 38. Protruding. On the other hand, when the sheet scattering preventing member 10 takes the lying posture, the first surface 18 a is retracted from the back wall 32, and the second surface 18 b is retracted from above the sheet accommodation space 38.

  According to the sheet feeding device 4 described above, the first surface 18a of the regulating surface 18 protrudes to a position higher than the back wall 32. Therefore, when viewed from the insertion direction A of the paper cassette 3, the insertion direction A It is a surface that obstructs. Further, since the second surface 18 b of the regulating surface 18 protrudes above the paper storage space 38, it is a surface facing the surface of the paper S in the paper storage space 38 from above. Therefore, even if the paper S in the paper storage space 38 jumps up to the right as shown in FIG. 5 due to an impact when the paper cassette 3 is inserted into the housing 2, the first surface 18 a and the first surface 18 a of the regulating surface 18. The second surface 18b can abut on the jumped paper S. As a result, the paper S is returned into the paper storage space 38 of the paper cassette 3 and scattering of the paper S is prevented. As a result, the feeding operation by the sheet feeding mechanism 40 can be performed smoothly.

  Further, in the paper feeding device 4, the first surface 18 a of the regulating surface 18 is an inclined surface that extends obliquely leftward and upward toward the upper side of the paper storage space 38 beyond the back wall 32. Therefore, as compared with a configuration in which the first surface 18a extends linearly upward so that the first surface 18a protrudes to a position higher than the back wall 32, the paper S that protrudes obliquely upward to the right as shown in FIG. It can be returned into the space 38.

  Further, in the paper feeding device 4, a pair of paper scattering preventing members 10 are arranged in the orthogonal direction orthogonal to the insertion direction A of the paper cassette 3, that is, a pair of regulating surfaces 18 are arranged in the orthogonal direction. Compared to the configuration using the single regulating surface 18, the paper S can be more reliably returned into the paper cassette 3.

  Further, in the paper feeding device 4, the interval P between the protrusions 12 of the paper scattering preventing member 10 is set so as to correspond to the minimum width dimension of the paper S. Up to a sheet S having a width dimension of 2 mm can be returned into the sheet cassette 3.

  Further, in the paper feeding device 4, when the paper scattering preventing member 10 takes the lying posture, the first surface 18 a is retracted from the back wall 32, and the second surface 18 b is retracted from above the paper accommodating space 38. Thereby, the feeding operation by the sheet feeding mechanism 40 is not hindered.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Housing | casing 3 Paper cassette 4 Paper feeder 10 Paper scattering prevention member 11 Elongate main-body part 12 Protrusion part 18 Restriction surface 18a 1st surface 18b 2nd surface 32 Back wall (downstream side wall part)
38 Paper storage space 40 Paper feed mechanism 50 Rotating member A Insertion direction (first direction)
S Paper T Paper bundle

Claims (6)

A housing,
A paper cassette having a sheet accommodating space for accommodating the paper, toward the first direction is insertable in the housing, downstream side wall located downstream of the first direction to form said sheet accommodating space A paper cassette having a section;
A paper feed mechanism for taking out and feeding the paper from the paper cassette along the first direction;
A main body provided on the downstream side in the first direction with respect to the downstream side wall, and the paper cassette of the paper that extends from the main body and is accommodated in the paper accommodation space is inserted into the housing. the sheet scattering prevention member having a restricting surface for the return contact with the paper only paper downstream wall beyond when you jump out from the paper cassette into the paper cassette when the,
With
The regulation surface includes a first surface that protrudes to a position higher than the downstream side wall portion, and a second surface that extends from an upper portion of the first surface and protrudes above the sheet accommodation space.   2. The paper feeding device according to claim 1, wherein the first surface is an inclined surface that extends toward the upper side of the paper storage space, beyond the downstream side wall portion.   3. The sheet feeding device according to claim 1, wherein a pair of the sheet scattering preventing members are arranged in an orthogonal direction orthogonal to the first direction. The sheet feeding device according to claim 3, wherein the sheet has a width dimension in the orthogonal direction,
A paper feeding device in which the interval between the paper scattering preventing members is set to correspond to a minimum width dimension.   5. The sheet feeding device according to claim 1, wherein when the sheet cassette is inserted into the housing, the first surface is higher than the downstream side wall portion. The first surface projects above the downstream side wall portion when the paper feeding mechanism feeds the paper. The sheet feeding device takes a second posture in which the second surface is retracted from above the sheet storage space. An image forming unit for forming a toner image on paper;
A paper feeding device for feeding the paper to the image forming unit;
With
An image forming apparatus using the sheet feeding device according to claim 1 as the sheet feeding device.

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