JP5331739B2 - 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 paper feeding operation is delayed.

  Accordingly, in view of the above circumstances, the present invention provides a paper feeding device that can smoothly perform paper 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.

In order to achieve the above object, a paper feeding device according to the present invention is a housing and a paper cassette for storing paper, which can be inserted into the housing from a first direction, and is viewed from the first direction. A paper cassette having a downstream side wall located on the downstream side, a paper feed mechanism for taking out and feeding the paper from the paper cassette along the first direction, and a paper cassette disposed in the housing. possess a regulating surface for returning the paper on the paper cassette wherein the sheet downstream wall beyond when you jump out from the paper cassette abuts when said inserted into the housing, and a pivot shaft When the paper cassette is inserted into the housing, the regulation surface takes a first posture that protrudes to a position higher than the downstream side wall, and when the paper feeding mechanism feeds the paper, the regulation surface Surface above the downstream side wall Wherein the sheet scattering prevention member taking the second position to retract a first rotating member disposed in the paper cassette, said and a biasing member disposed within the housing, the paper scattering prevention member from A switching member that switches between the first posture and the second posture, and the switching member rotates the paper scattering preventing member around the axis of the swing shaft, thereby the paper scattering preventing member. The first posture is switched between the first posture and the second posture, and the first rotating member has a first rotating shaft and one end and the other end sandwiching the first rotating shaft. And a member that is rotatable about the first rotation shaft and has a restricting portion capable of restricting the turning operation at the one end portion, and abuts against the paper scattering preventing member. An abutting portion that can be mounted on the other end, and the urging member When the paper anti-scattering member is urged so that the disturbance preventing member always takes the second posture, and the paper cassette is inserted into the housing, the contact portion rotates the regulating portion. In contact with the paper scattering preventing member in a restricted state, the paper scattering preventing member is pressed from the second posture by pressing the paper scattering preventing member against the biasing force of the biasing member. On the other hand, when the paper feeding mechanism feeds the paper, the restricting portion permits a rotation operation and cancels the contact state between the contact portion and the paper scattering preventing member. By doing so, the paper scattering preventing member is switched from the first posture to the second posture by the biasing force of the biasing member .

According to the paper feeding device of the present invention, when the paper cassette is inserted into the housing, the paper scattering preventing member takes the first posture in which the regulating surface protrudes to a position higher than the downstream side wall portion. The surface can come into contact with the sheet that is about to jump out of the sheet cassette beyond the downstream side wall due to an impact when the sheet cassette is inserted, and the sheet can be returned to the sheet cassette. Thereby, scattering of the paper is prevented, and as a result, the paper feeding operation by the paper feeding mechanism can be performed smoothly. Further, when the paper feeding mechanism feeds the paper, the paper scattering preventing member takes the second posture in which the regulating surface is retracted from above the downstream side wall portion, and thus does not hinder the paper feeding operation of the paper feeding mechanism. Further, according to this configuration, the posture of the paper scattering preventing member can be switched with a simple configuration in which the paper scattering preventing member is rotated by the switching member.

  In still another preferred embodiment of the present invention, the paper cassette has a lift plate capable of moving up and down on which the paper is placed, and the lift plate is inserted when the paper cassette is inserted into the housing. On the other hand, when the sheet feeding mechanism feeds the sheet, the position is set to the raised position, and the restricting portion of the switching member has a shape capable of engaging with the lift plate. The first rotating member is rotated by maintaining a state where the first cassette is engaged with the lift plate set at the lowered position when the paper cassette is inserted into the housing. On the other hand, when the paper feeding mechanism feeds the paper, the rotating state of the first rotating member is allowed by releasing the engagement state with the lift plate set at the raised position. To do.

  According to this configuration, the posture of the paper scattering preventing member can be switched in accordance with the lifting / lowering operation of the lift plate, that is, the paper cassette inserting operation and the paper feeding mechanism.

  In still another preferred embodiment of the present invention, the contact portion has a first contact surface that contacts the paper scattering prevention member, and the paper scattering prevention member contacts the first contact surface. A second contact surface, and the biasing member is directed from the second contact surface toward the first contact surface in a state where the first contact surface and the second contact surface are in contact with each other. The urging force is applied so that a load is applied.

  According to this configuration, since a load is applied from the second contact surface of the paper scattering prevention member toward the first contact portion of the contact portion, it is easy to hold the paper scattering prevention member in the first posture. It becomes.

  In still another preferred embodiment of the present invention, the contact portion includes a second rotation shaft and a first contact surface that contacts the paper scattering preventing member, and the shaft of the second rotation shaft. The sheet-scattering preventing member is configured to include a second abutting member that abuts against the first abutting surface. And when the sheet scattering preventing member is switched to the second posture, the first rotating member has the first abutting surface and the first abutting surface and the second abutting surface. The sheet scattering preventing member is rotated so as to move to the downstream side in the first direction when viewed from the abutting position, while the second abutting surface of the sheet scattering preventing member is in the first direction as viewed from the abutting position. Rotate to move upstream.

  When the paper scattering prevention member is switched to the second position, the first contact surface rotates so as to move downstream in the first direction as viewed from the contact position, while the second contact surface The first contact surface comes into contact with the second contact surface when the paper cassette is pulled out from the housing because it moves upstream in the first direction when viewed from the contact position. However, according to the above configuration, the second rotation member having the first contact surface can rotate with respect to the first rotation member, so that the first contact surface becomes the second contact surface. The contact pressure to be applied can be reduced while rotating. Thereby, the operation of pulling out the paper cassette from the housing is smoothly performed.

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. The sheet feeding device according to any one of 1 to 4 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 feeding is prevented from being scattered. 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. A state immediately before the paper cassette is inserted into the housing and the paper scattering preventing member takes a standing posture is shown. It is a side view of a paper scattering prevention member and a switching member, and shows a state in which the paper scattering prevention member takes a standing posture. It is a perspective view of a paper scattering prevention member and a switching member, and shows a state in which the paper scattering prevention member takes a standing posture. It is a side view of a paper scattering prevention member and a 1st rotation member, and shows the state where a paper scattering prevention member took a lying posture. It is a perspective view of a paper scattering prevention member and a 1st rotation member, and shows the state where a paper scattering prevention member took a lying posture.

  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 sheet feeding device viewed from the back wall side of the sheet cassette, and shows the standing posture of the sheet scattering preventing member. FIG. 4 is a perspective view of the paper feeding device as viewed from above the paper cassette, and shows the standing posture of the paper 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. 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 paper scattering prevention member 10 has an elongated block-shaped main body 11 and a protrusion 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. 10 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 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 continuous from the first surface 18a. The first surface 18a is a sloped surface that extends diagonally upward (left diagonally upward in FIG. 5) while passing through the back wall 32. The second surface 18b is a surface that extends in the substantially horizontal direction on the sheet storage space 38 from the upper edge of the first surface 18a. The first surface 18 a and the second surface 18 b of the regulating surface 18 abut against the paper S about to jump out and return the paper S to the paper cassette 3. 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. 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 10) in the clockwise direction in FIG. By this rotation operation, the protruding portion 12 (that is, the regulating surface 18) 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.

  In the present embodiment, a switching member is used to switch the posture of the paper scattering preventing member 10 between a standing posture and a lying posture. First, in addition to FIG. 5, refer to FIGS. 8 to 10 for a configuration in which the posture of the paper scattering preventing member 10 is switched from the lying posture to the standing posture when the paper cassette 3 is inserted into the housing 2 by the switching member. While explaining. FIG. 8 shows a state immediately before the paper cassette 3 is inserted into the housing 2 and the paper scattering prevention member 10 takes an upright posture. FIG. 9 is a side view of the paper scattering preventing member 10 and the switching member, and shows a state in which the paper scattering preventing member 10 takes an upright posture. FIG. 10 is a perspective view of the paper scattering preventing member 10 and the switching member, and shows a state in which the paper scattering preventing member 10 takes a standing posture.

  The switching member includes the first rotating member 50 and the spring member 14 described above. The first rotating member 50 rotates the paper scattering preventing member 10 from the state shown in FIG. 6 around the axis of the swing shaft 16 in the counterclockwise direction in FIGS. The ten postures can be switched from the lying posture to the standing posture. As described above, the spring member 14 rotates the paper scattering preventing member 10 around the swinging shaft 16 in the clockwise direction, that is, in the direction opposite to the first rotating member 50, thereby preventing paper scattering. The biasing force is applied so that the member 10 always takes the lying posture. Therefore, the first rotating member 50 needs to rotate the paper scattering preventing member 10 against the urging force of the spring member 14.

  First, the configuration of the first rotating member 50 will be described. The first rotating member 50 is a member that is disposed on the outer surface side of the back wall 32 of the sheet cassette 3 and that is disposed between the pair of sheet scattering preventing members 10 on the outer surface side. The first rotation member 50 includes a rotation member main body 51 and a rotation piece 52 (second rotation member).

  As shown in FIG. 10, the rotation member main body 51 includes a pair of side walls 56 adjacent to each other in a direction orthogonal to the insertion direction A of the paper cassette 3, a connection wall 58 that connects the side walls 56, and a first rotation. And a shaft 53.

  The first rotation shaft 53 is an axis that passes through the side walls 56 and extends along the back wall 32 in a direction orthogonal to the insertion direction A of the paper cassette 3, and allows the rotation member main body 51 to rotate. The installation position of the first rotation shaft 53 is set so that the rotation member main body 51 rotates in its clockwise direction in FIGS. 5 and 8 under its own weight.

  The rotating member main body 51 has one end and the other end with the first rotating shaft 53 interposed therebetween. The one end portion is a portion that extends into the paper cassette 3 through a through hole 32 a formed in the lower portion of the back wall 32, and is configured as a restriction portion 55. The restricting portion 55 is a portion that restricts the rotating member main body 51 from rotating in the clockwise direction by its own weight, and has a shape that can be engaged with the distal end portion 381 a of the lift plate 381. Both the restriction portion 55 and the tip end portion 381a of the lift plate 381 are set in a hook shape. The lift plate 381 is set at the lowered position when the paper cassette 3 is inserted into the housing 2, and the leading end 381 a is engaged with the restricting portion 55. In this state, the restricting portion 55 is pressed from above by the tip portion 381a. Therefore, the clockwise rotation of the rotation member main body 51 is restricted by the restriction portion 55.

  On the other hand, when the lift plate 381 is set to the raised position, the distal end portion 381a is separated from the restricting portion 55, and the engaged state between the distal end portion 381a and the restricting portion 55 is released. In this state, the restricting portion 55 allows the rotating member body 51 to rotate clockwise. Note that the shape of the restriction portion 55 and the tip portion 381a of the lift plate 381 is not limited to the hook shape, and may be any shape as long as the tip portion 381a can press the restriction portion 55 from above.

  The other end portion of the rotating member main body 51 acts as a contact portion that can contact the paper scattering preventing member 10. In the present embodiment, the contact portion is constituted by the rotating piece 52. As shown in FIG. 10, an opening is formed between the pair of side walls 56 in the upper part of the rotating member main body 51, and a rotating piece 52 is disposed in the opening.

  The rotating piece 52 has a second rotating shaft 54 that penetrates both side walls 56 and extends in parallel with the first rotating shaft 53, and is arranged around the axis of the second rotating shaft 54 with respect to the rotating member main body 51. And is rotatably supported. As shown in FIG. 10, a regulating wall 57 protruding from the opening is formed on a portion of the connecting wall 58 of the rotating member main body 51 opposite to the portion facing the back wall 32. As shown in FIG. 5, in the rotating piece 52, the clockwise rotating operation is restricted by the connecting wall 58, and the counterclockwise rotating operation is restricted by the restricting wall 57.

  An upper end portion of the rotating piece 52 protrudes upward from the opening, and an upper surface thereof is configured as a first contact surface 59 that contacts the paper scattering preventing member 10. On the other hand, the paper scattering preventing member 10 has a second contact surface 17 that can contact the first contact surface 59. The second contact surface 17 is actually set on the connecting member 15 that connects the pair of paper scattering preventing members 10. The second contact surface 17 is set at a position in the vicinity of one of the paper scattering preventing members 10 on the bottom surface of the connecting member 15.

  Next, a procedure for switching the posture of the paper scattering preventing member 10 from the lying posture to the standing posture by the first rotating member 50 having the above configuration will be described. First, as shown in FIG. 8, when the first rotating member 50 approaches the paper scattering preventing member 10 in the lying posture in the housing 45 (FIG. 7) as the paper cassette 3 is inserted, the first rotating member 50 is moved. The first contact surface 59 of the rotating piece 52 of the member 50 contacts the edge portion (the right edge portion in FIG. 8) of the second contact surface 17 of the paper scattering preventing member 10. When the first abutment surface 59 abuts against the second abutment surface 17, the rotation piece 52 tries to rotate counterclockwise due to the impact, but the rotation operation of the first abutment surface 59 is performed by the first rotation member 50. It is restricted by the restriction wall 57. Then, as the first rotating member 50 further enters, the rotating piece 52 presses the second contact surface 17 via the first contact surface 59 while resisting the biasing force of the spring member 14. Therefore, the paper scattering preventing member 10 starts to rotate in the counterclockwise direction while being pushed up.

  When the rotating piece 52 continues to transmit the contact pressure from the first contact surface 59 to the second contact surface 17 while resisting the urging force of the spring member 14, the sheet scattering preventing member 10 is counterclockwise. And the second contact surface 17 overlaps the first contact surface 59 as shown in FIG. Thereby, the paper scattering preventing member 10 changes from the lying posture to the standing posture.

  As shown in FIG. 9, the urging member is a paper scattering prevention member so that a load F is applied from the second contact surface 17 toward the first contact surface 59 when the paper scattering prevention member 10 is in the standing posture. An urging force is applied to 10. Thereby, it becomes easy to hold the paper scattering preventing member 10 in the standing posture.

  In this embodiment, the position where the load F is applied to the first contact surface 59 is set to the second rotation shaft 54 of the rotation piece 52 in order to securely hold the paper scattering prevention member 10 in the standing posture. With respect to the vertical axis L extending in the vertical direction, the sheet scattering prevention member 10 is set on the swing shaft 16 side. By setting the load acting position in this way, it is possible to prevent the rotating piece 52 from rotating in the clockwise direction. Further, by setting the load position as described above, the rotating piece 52 tries to rotate counterclockwise by the load F, but the rotating operation of the rotating piece 52 is the restriction wall 57 of the first rotating member 50. Regulated by. Thereby, the paper scattering preventing member 10 can be reliably held in the standing posture. When the position where the load F is applied to the first contact surface 59 is set on the side opposite to the swing shaft 16 when viewed from the perpendicular L, the rotating piece 52 is rotated clockwise by the load F. It becomes easy to move, and it becomes difficult to hold the paper scattering preventing member 10 in the standing posture.

  Next, a procedure for switching the paper scattering preventing member 10 from the standing posture to the lying posture will be described with reference to FIGS. 11 and 12 in addition to FIG. FIG. 11 is a side view of the paper scattering preventing member 10 and the first rotating member 50 and shows a state in which the paper scattering preventing member 10 takes a lying posture. FIG. 12 is a perspective view of the paper scattering preventing member 10 and the first rotating member 50 and shows a state in which the paper scattering preventing member 10 takes a lying posture. In FIG. 12, the spring member 14 is omitted.

  Before the paper feeding mechanism 40 takes out the paper S from the paper cassette 3 and feeds it along the feeding path, the lift plate 381 of the paper cassette 3 is set to the raised position by the lifting mechanism. When the lift plate 381 is set at the raised position, the tip end portion 381a of the lift plate 381 is separated upward from the restricting portion 55 of the first rotating member 50, so that the engagement state between the tip end portion 381a and the restricting portion 55 is established. It will be resolved. As a result, the restricting portion 55 allows the turning member main body 51 of the first turning member 50 to turn clockwise due to its own weight. Accordingly, the rotating piece 52 also rotates in the clockwise direction, so that the first contact surface 59 of the rotating piece 52 is separated from the second contact surface 17 of the paper scattering preventing member 10 and is in the contact state. Is resolved. Therefore, the paper scattering preventing member 10 is rotated in the clockwise direction by the urging force of the spring member 14 and takes a lying posture. The paper scattering preventing member 10 in the lying posture is housed in the recess 46 of the housing 45 (FIG. 7).

  When the paper scattering preventing member 10 takes the lying posture, the first rotating member 50 rotates clockwise by its own weight as described above, and therefore the first contact surface 59 is the first contact surface 59. And the second contact surface 17 moves to the downstream side in the insertion direction A when viewed from the contact position B. On the other hand, since the paper scattering preventing member 10 is rotated clockwise by the spring member 14, the second contact surface 17 moves to the upstream side in the insertion direction A when viewed from the contact position B.

  Therefore, when the paper cassette 3 is pulled out from the housing 2 in the direction opposite to the insertion direction A, the upstream edge portion (the right edge portion in FIG. 11) of the first contact surface 59 viewed from the insertion direction A is the connecting member. 15 abuts on a portion defining the second abutment surface 17. However, in the present embodiment, the rotating piece 52 can be rotated in the clockwise direction, so that the contact pressure that the first contact surface 59 acts on the portion is reduced while rotating in the clockwise direction. Can be made. Thereby, the paper cassette 3 is smoothly pulled out from the housing 2.

  According to the paper feeding device 4 according to the present embodiment described above, when the paper cassette 3 is inserted into the housing 2, the paper scattering preventing member 10 protrudes to a position where the regulation surface 18 is higher than the back wall 32. Therefore, the regulation surface 18 comes into contact with the paper S about to jump out of the paper cassette 3 over the back wall 32 due to an impact when the paper cassette 3 is inserted, and puts the paper S into the paper cassette 3. Can be returned. Thereby, scattering of the paper S is prevented, and as a result, the feeding operation by the paper feeding mechanism 40 can be performed smoothly. Further, when the paper feeding mechanism 40 feeds the paper S, the paper scattering preventing member 10 takes the second posture in which the regulating surface 18 is retracted from above the rear wall 32, so that the paper feeding operation of the paper feeding mechanism 40 is performed. Not disturb.

  Further, in the paper feeding device 4, the paper scattering prevention member 10 is rotated by the first rotation member 50 to switch the posture from the lying down posture to the standing posture, and the paper scattering prevention member 10 is rotated by the spring member 14. Since the posture is switched from the standing posture to the lying posture, a driving mechanism using a motor or the like is not used for switching the posture of the paper scattering preventing member 10. Accordingly, the configuration of the paper feeding device 4 can be simplified.

  Further, in the paper feeding device 4, the posture of the paper scattering preventing member 10 can be switched in accordance with the lifting / lowering operation of the lift plate 381, that is, the insertion operation of the paper cassette 3 and the feeding operation by the paper feeding mechanism 40. .

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Housing | casing 3 Paper cassette 4 Paper feeding apparatus 10 Paper scattering prevention member 14 Spring member (biasing member)
15 Connecting member 16 Oscillating shaft 17 Second contact surface 18 Restricting surface 32 Back wall (downstream side wall)
40 Paper Feed Mechanism 45 Housing 50 First Rotating Member 51 Rotating Member Body 52 Rotating Piece (Second Rotating Member)
53 1st rotation axis 54 2nd rotation axis 55 Restriction part 59 1st contact surface A Insertion direction (1st direction)
S Paper T Paper bundle

Claims (5)

A housing,
A paper cassette for storing paper, the paper cassette being insertable into the housing from a first direction and having a downstream side wall portion located downstream from the first direction;
A paper feed mechanism for taking out and feeding the paper from the paper cassette along the first direction;
Arranged in the housing for returning the paper to the paper cassette by abutting against the paper that is about to jump out of the paper cassette beyond the downstream side wall when the paper cassette is inserted into the housing. a regulating surface, and a pivot shaft possess, when the paper cassette is inserted in the housing, it takes the first posture in which the regulating surface is protruded at a position higher than the downstream wall, the sheet feeding mechanism When the paper is fed, a paper scattering preventing member that takes a second posture in which the regulating surface is retracted from above the downstream side wall portion ;
A switch having a first rotating member arranged in the paper cassette and an urging member arranged in the casing, and switching the paper scattering preventing member between the first posture and the second posture. A member, and
The switching member switches the posture of the paper scattering prevention member between the first posture and the second posture by rotating the paper scattering prevention member about the axis of the swing shaft,
The first rotating member has a first rotating shaft and one end portion and the other end portion sandwiching the first rotating shaft, and is a member that can rotate around the axis of the first rotating shaft. In addition, the one end portion has a restricting portion capable of restricting the rotation operation, and the other end portion has a contact portion capable of contacting the paper scattering preventing member.
The biasing member biases the paper scattering preventing member so that the paper scattering preventing member always takes the second posture;
When the paper cassette is inserted into the housing, the abutting portion abuts against the paper scattering preventing member in a state where the restricting portion restricts the rotation operation, and resists the urging force of the urging member. While pressing the paper scattering prevention member, the paper scattering prevention member is switched from the second posture to the first posture,
On the other hand, when the paper feeding mechanism feeds the paper, the restricting portion allows a rotation operation and eliminates the contact state between the contact portion and the paper scattering preventing member, A paper feeding device that switches the paper scattering preventing member from the first posture to the second posture by a biasing force of the biasing member . The sheet feeding device according to claim 1 , wherein the sheet cassette includes a lift plate capable of moving up and down on which the sheet is placed,
The lift plate is set to a lowered position when the paper cassette is inserted into the housing, and is set to a raised position when the paper feed mechanism feeds the paper,
The restricting portion of the switching member is a portion having a shape capable of engaging with the lift plate, and the lift set at the lowered position when the paper cassette is inserted into the housing. The lift plate that is set at the raised position when the paper feeding mechanism feeds the paper while restricting the turning operation of the first turning member by maintaining the engaged state with the plate The paper feeding device that allows the first rotating member to rotate by releasing the engagement state. 3. The sheet feeding device according to claim 1 , wherein the contact portion has a first contact surface that contacts the sheet scattering prevention member,
The paper scattering preventing member has a second contact surface that contacts the first contact surface,
The biasing member applies a biasing force so that a load is applied from the second contact surface toward the first contact surface in a state where the first contact surface and the second contact surface are in contact with each other. Paper feeding device to be operated. 3. The sheet feeding device according to claim 1 , wherein the contact portion includes a second rotation shaft and a first contact surface that contacts the sheet scattering prevention member, and the second rotation shaft. A second rotating member supported so as to be rotatable with respect to the first rotating member around the axis of
The paper scattering preventing member has a second contact surface that contacts the first contact surface,
When the paper scattering preventing member is switched to the second posture, the first rotating member has the first abutting surface moved from the abutting position between the first abutting surface and the second abutting surface. The sheet scattering prevention member moves to the upstream side in the first direction when the second contact surface is viewed from the contact position. Paper feeding device that rotates as if 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
As the paper feeding apparatus, an image forming apparatus sheet feeding apparatus is used according to any one of claims 1-4.

Images