Sheet feeding device and image forming apparatus equipped with same

Abstract

To provide a sheet feeder capable of temporally dispersing a load applied to a roller holder, and an image forming device equipped with the same.SOLUTION: There is provided a sheet feeder 6 having a pickup roller 60 for pulling out an uppermost sheet of stacked sheets, which comprises a roller holder 7 for pivotally supporting the pickup roller 60 in a swingable manner and a pair of sheet regulating parts 8 disposed on both sides of the roller holder 7 in the rotational axis direction of the pickup roller 60. The pair of sheet regulating parts 8 are formed so as to switchably block the stacked sheets. The pair of sheet regulating parts 8 receive a reaction force due to swinging of the pickup roller 60 caused by the roller holder 7, at the timing different from each other, to switch between blocking and releasing states.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sheet feeding device and an image forming apparatus including the same. [Background technology]

[0002] A sheet feeder that sends out sheets to a sheet transport path generally includes a pickup roller that pulls out the top sheet among stacked sheets, a pair of roller holders that hold the pickup roller and can swing, and a sheet regulating unit that blocks the stacked sheets. Conventionally, there are known sheet feeders that switch the blocking state of the sheet regulating unit in conjunction with the descent of the pickup roller or the swinging of the roller holder (for example, Patent Document 1) and change the position of the sheet regulating unit (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-96935 A [Patent Document 2] JP 2012-153522 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional sheet feeder, it is conceivable that the load applied when switching the blocked state of the sheet regulating unit is applied to both roller holders at the same time, and it is required to distribute the load on the roller holders over time in order to smoothly lower the pickup roller.

[0005] The present invention has been made to solve the above-mentioned conventional problems, and has an object to provide a sheet feeding device that can distribute the load on a roller holder over time, and an image forming apparatus equipped with the same. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a sheet feeding device including a pickup roller for picking up an uppermost sheet among stacked sheets, Shake Movably supported was done A roller holder; A pickup roller journaled by the roller holder; a pair of sheet regulating portions provided on both sides of the roller holder in a rotational axis direction of the pickup roller, the pair of sheet regulating portions being configured to regulate the sheet A passage through which Switchable blocking, When the roller holder swings, The pair of sheet regulating portions are arranged to move at different timings. , connoisseur The device is characterized in that it is configured to switch between closed states.

[0007] In the sheet supply device, each of the pair of sheet regulating portions includes a rotatable sheet regulating piece, a stopper capable of regulating the rotation of the sheet regulating piece, before Rotation of the sheet regulating piece The stopper for and a stopper release portion for releasing the restriction of the pair of sheet restricting portions, the stopper release portion of each of the pair of sheet restricting portions releasing the restriction of the stopper at different timings. Pa's The restriction may be lifted.

[0008] In the sheet supply device, the stoppers in the pair of sheet regulating portions each have a rotatable lock arm, The above Lock Arm teeth, The rotation of the sheet regulating piece may be restricted by interfering with the sheet regulating piece.

[0009] In the sheet supplying device, the stoppers of the pair of sheet regulating portions are each Rotation You may do so.

[0010] In the sheet supply device, the stoppers in the pair of sheet regulating portions each have a pressed arm that rotates the lock arm in a predetermined direction when pressed, and the stopper release portions in the pair of sheet regulating portions each include a pressing protrusion attached to the roller holder, and the pressing protrusion is disposed on the roller holder. When the , the pressed arm of Press the Stopper restriction lifted It may be allowed.

[0011] In the sheet supplying device, Before The pressing protrusions are pressed at different times. Press the pressed arm The roller holder may be disposed on the roller holder so as to

[0012] In the sheet supplying device, Before Among the pressing protrusions, one pressing protrusion that starts pressing the pressed arm first presses the pressed arm at a position farther from the pivot point of the pressed arm than the other pressing protrusion. of The roller holder may be disposed on the roller holder so as to apply pressure thereto.

[0013] In addition, in the sheet supplying device, the stoppers in the pair of sheet regulating portions may each interfere with the sheet regulating piece with the lock arm to regulate the rotation of the sheet regulating piece when the pressed arm is released from the pressure from the pressing protrusion.

[0014] The image forming apparatus described in the present application is characterized by including the sheet supplying device described above. Effect of the Invention

[0015] According to the present invention, the load on the roller holder can be dispersed over time. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing a configuration of an image forming apparatus according to a first embodiment. [Diagram 2] 11 is a partially cutaway front view of the sheet feeder in a state in which the rotation of the sheet regulating piece is regulated, as viewed from the front. FIG. [Diagram 3] 11 is a partially cutaway front view of the sheet feeder seen from the front in a state in which the restriction on the rotation of the sheet restricting piece is released; FIG. [Figure 4] 13 is a partially cutaway front view showing a state in which a stopper release portion of the front sheet regulating portion starts to press against the stopper, as viewed from the front. FIG. [Diagram 5] 13 is a partially cutaway rear view showing a state in which a stopper release portion of the rear sheet regulating portion starts to press against the stopper, as viewed from the rear. FIG. [Figure 6] 13 is a partially cutaway front view of a state in which a stopper release portion of a front sheet regulating portion starts to press against a stopper in the third embodiment, as viewed from the front. FIG. [Figure 7] 13 is a partially cutaway rear view showing a state in which a stopper release portion of a rear sheet regulating portion starts to press against a stopper in the third embodiment, as viewed from the rear. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the same components in the embodiments described below are designated by the same reference numerals, and redundant descriptions of those components will be omitted.

[0018] (Embodiment 1) -Overall configuration of image forming apparatus- First, the overall configuration of the image forming apparatus A in the first embodiment will be described.

[0019] FIG. 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus A in the first embodiment. In the figure, the symbol X indicates the width direction (depth direction), with the -X direction (negative X direction) being the front direction and the +X direction (positive X direction) being the rear direction. The symbol Y indicates the left-right direction Y perpendicular to the width direction X, with the -Y direction (negative Y direction) being the left direction and the +Y direction (positive Y direction) being the right direction. The symbol Z indicates the up-down direction, with the -Z direction (negative Z direction) being the down direction and the +Z direction (positive Z direction) being the up direction. These settings are the same in the following embodiments.

[0020] The image forming apparatus A is an electrophotographic image forming apparatus, and is an intermediate transfer type color multifunction machine capable of printing full color images. The image forming apparatus A includes an image reading unit 1 and an image forming apparatus main body B (see FIG. 1). In this embodiment, the image forming apparatus A uses toners of the colors yellow (Y), magenta (M), cyan (C) and black (K) for printing.

[0021] The image reading unit 1 reads an image from a document, and is provided on the upper part of the image forming apparatus A. The image reading unit 1 has a document reading device 10, a document placement table 11, and an automatic document processing device 12 (see FIG. 1).

[0022] The document reading device 10 irradiates a document with light and reads an image from the document based on the reflected light. The document placement table 11 is a portion on which a document is placed by a user, and is provided above the document reading device 10. The document placement table 11 is made of transparent glass. The automatic document processing device 12 is provided above the document placement table 11, and automatically and continuously transports documents inserted by a user to the document reading device 10. The image of the document is read by the document reading device 10 while the document is placed on the document placement table 11 or while the document is transported to the document reading device 10 by the automatic document processing device 12.

[0023] The image forming apparatus main body B has an image forming section 2, an intermediate transfer body 3, a secondary transfer section 40, a fixing device 41, a manual feed tray 42, a sheet storage section 43, a sheet roller group 5, and a sheet discharge section 50 (see FIG. 1). The image forming apparatus A is provided with a sheet transport path S along which sheets are transported.

[0024] The image forming section 2 forms a toner image of each color based on image data, and includes an exposure device 20, a developing device 21, an image carrier 22, a charger 23, and a cleaning unit 24 (see FIG. 1).

[0025] The exposure device 20 exposes the surface of the image carrier 22, which has been charged by the charger 23, to light corresponding to each color, thereby forming an electrostatic latent image corresponding to each color on the image carrier 22. The development device 21 develops (visualizes) the electrostatic latent image formed on the surface of each image carrier 22 with toner of each color (Y, M, C, K) supplied from the toner cartridge T to form a toner image. The image carrier 22, on whose surface an electrostatic latent image is formed, is rotated in a predetermined direction by driving a main motor (not shown). The toner image visualized on the image carrier 22 is conveyed to the intermediate transfer body 3 by the rotational drive of the image carrier 22. The charger 23 uniformly charges the surface of the image carrier 22 to a predetermined potential. The cleaning unit 24 removes and collects toner remaining on the surface of the image carrier 22 after development and image transfer. A series of operations according to the above configuration forms a toner image of each color on the surface of each image carrier 22.

[0026] The intermediate transfer body 3 is used for the primary transfer, and is disposed above the image carrier 22. Here, "primary transfer" refers to the transfer of the toner images of each color formed on the image carrier 22 onto the intermediate transfer belt 30. The intermediate transfer body 3 has the intermediate transfer belt 30, a driving roller 31, a driven roller 32, and a primary transfer roller 33 (see FIG. 1).

[0027] The intermediate transfer belt 30 is an endless belt that rotates in a predetermined direction, and is suspended between a drive roller 31 and a driven roller 32. The toner images of each color visualized on the image carrier 22 are transferred to the intermediate transfer belt 30 in a superimposed manner, and are conveyed to the secondary transfer section 40 by the rotation of the intermediate transfer belt 30. The drive roller 31 is a roller that is driven to rotate in a predetermined direction by the drive of a belt motor (not shown), and is provided on one end side of the intermediate transfer body 3. The intermediate transfer belt 30 is rotated by the rotation drive of the drive roller 31. The driven roller 32 is a roller that is rotatably provided along the intermediate transfer belt 30. The driven roller 32 is rotated according to the rotation of the intermediate transfer belt 30. The primary transfer rollers 33 are arranged in a row so as to correspond to the image carrier 22 via the intermediate transfer belt 30. A transfer bias is applied to the primary transfer roller 33, so that the toner image of the image carrier 22 is transferred to the intermediate transfer belt 30.

[0028] The secondary transfer unit 40 is used for secondary transfer, and is disposed on the sheet transport path S. Here, "secondary transfer" refers to the transfer of the toner images of each color transferred onto the intermediate transfer belt 30 onto a sheet.

[0029] The fixing device 41 fixes the toner image onto the sheet by heating and melting the toner image that has been secondarily transferred onto the sheet and fixing it onto the sheet, and is provided downstream of the secondary transfer section 40 on the sheet transport path S.

[0030] Manual feed tray 42 is capable of placing sheets to be fed to image forming apparatus body B of image forming apparatus A, and is attached so as to be rotatable and openable relative to image forming apparatus body B. In this specification, "rotation" includes movement in forward and reverse directions around a certain axis, and rotation around a certain axis.

[0031] When the manual feed tray 42 is opened, a sheet supply port 420 is formed. A sheet supply device 6 that feeds a sheet from the manual feed tray 42 to the sheet transport path S through the sheet supply port 420 is provided on the base end side of the manual feed tray 42. The sheet supply device 6 will be described in detail later.

[0032] The sheet storage section 43 is capable of storing sheets to be supplied to the image forming apparatus main body B, and is disposed at the bottom of the image forming apparatus A.

[0033] The sheet roller group 5 includes a pickup roller 5a, conveying rollers 5b to 5e, and a registration roller 5f. The pickup roller 5a pulls out the top sheet of the sheets in the sheet storage unit 43 and supplies it to the sheet conveying path S. The conveying rollers 5b to 5e convey the sheet along the sheet conveying path S. The registration roller 5f temporarily stops the sheet conveyed from the sheet storage unit 43 and aligns the leading edge of the sheet. Each of the sheet rollers 5 is rotated by driving a motor (not shown).

[0034] The sheet discharge section 50 is provided on the upper part of the image forming apparatus A, and is used to load and pull out printed sheets face down.

[0035] The image forming apparatus A performs printing on a sheet as follows. First, the image forming unit 2 forms a toner image based on image data generated by the image reading unit 1 or supplied from an external device. The primary transfer roller 33 performs primary transfer of the toner image onto the intermediate transfer belt 30 of the intermediate transfer body 3. During this time, the pickup roller 5a pulls out the sheet from the sheet storage unit 43, the conveying roller 5b conveys the sheet to the registration roller 5f, and the registration roller 5f conveys the sheet to the secondary transfer unit 40. Next, the secondary transfer unit 40 performs secondary transfer of the toner image primarily transferred onto the intermediate transfer belt 30 onto the sheet. The fixing device 41 fixes the toner image secondarily transferred onto the sheet. Thereafter, the conveying roller 5e conveys the sheet and discharges it onto the sheet discharge unit 50, completing the printing on the sheet.

[0036] -Sheet supply device- Next, the sheet supplying device 6 in this embodiment will be described.

[0037] Fig. 2 is a partially cutaway front view of the sheet feeder 6 seen from the front in a state in which the rotation of the sheet regulating piece 80 is regulated. Fig. 3 is a partially cutaway front view of the sheet feeder 6 seen from the front in a state in which the restriction on the rotation of the sheet regulating piece 80 is released. In Figs. 2 and 3, the rear roller holder 7b and the rear sheet regulating portion 8b are omitted. Also, in the drawings, the manual feed tray 42 is omitted.

[0038] The sheet supply device 6 includes a pickup roller 60, a supply roller 61, a separation roller 62, a roller holder 7, and a pair of sheet regulating units 8 (see FIGS. 2 and 3). A drive belt 63 is suspended between the pickup roller 60 and the supply roller 61.

[0039] The pickup roller 60 is for pulling out the top sheet among the sheets placed on the manual feed tray 42 , and is rotated following the rotation of the drive belt 63 caused by the rotation of the supply roller 61 .

[0040] The supply roller 61 sends out the top sheet picked up by the pickup roller 60 to the sheet transport path S, and has a support shaft 64 supported by a frame (not shown). The supply roller 61 is rotated by the drive of a motor (not shown).

[0041] The separation roller 62 separates the top sheet from one or more other sheets when they are pulled out next to the top sheet, and is journaled by a frame (not shown) so as to face the supply roller 61. The separation roller 62 is rotated in accordance with the rotation of the supply roller 61.

[0042] The roller holder 7 pivotally supports the pickup roller 60 so that it can swing, and is composed of a front roller holder 7a that supports the front end of the pickup roller 60, and a rear roller holder 7b that pairs with the front roller holder 7a and supports the rear end of the pickup roller 60. In this embodiment, the roller holders 7a and 7b are provided so as to be able to swing integrally in the Q direction with the support shaft 64 of the supply roller 61 as a swing fulcrum. Hereinafter, the swing direction of the roller holder 7 in which the pickup roller 60 approaches the manual feed tray 42 is defined as the +Q direction, and the swing direction of the roller holder 7 in which the pickup roller 60 moves away from the manual feed tray 42 is defined as the -Q direction (see FIG. 2). The roller holder 7 is swung by a drive unit (not shown). For example, a rotary solenoid is used as the drive unit. The roller holder 7 causes the pickup roller 60 to swing toward the manual feed tray 42 (in the +Q direction), whereby the pickup roller 60 comes into contact with the top sheet and pulls out the top sheet.

[0043] The pair of sheet regulating parts 8 are provided on both sides of the roller holder 7 in the direction of the rotation axis of the pickup roller 60 to switch between sheets in response to the swinging of the pickup roller 60 by the roller holder 7 (see Figs. 2 and 3). The sheet regulating parts 8 are composed of a front sheet regulating part 8a provided on the front side of the roller holder 7a and a rear sheet regulating part 8b provided on the rear side of the roller holder 7b. Each of the sheet regulating parts 8a and 8b has a sheet regulating piece 80, a stopper 81, and a stopper release part 82 (see Figs. 2 and 3). In the following description of the components of the front sheet regulating part 8a and the rear sheet regulating part 8b, the suffix "a" is added to the reference numeral of each component of the front sheet regulating part 8a, and the suffix "b" is added to the reference numeral of each component of the rear sheet regulating part 8b. For example, the sheet regulating piece 80 of the front sheet regulating portion 8a is indicated as sheet regulating piece 80a, and the sheet regulating piece 80 of the rear sheet regulating portion 8b is indicated as sheet regulating piece 80b. On the other hand, when there is no particular distinction between the front sheet regulating portion 8a and the rear sheet regulating portion 8b in the description of each component, the reference numeral of each component will not have an "a" or "b" suffixed thereto.

[0044] The sheet restricting piece 80 is supported by a frame (not shown) so as to be rotatable about an axis δ. An engaged portion 83 with which the stopper 81 can be engaged is provided at the base end of the sheet restricting piece 80. The engaged portion 83 is formed in a substantially hook shape.

[0045] The stopper 81 is capable of restricting the rotation of the sheet restricting piece 80, and has a rotatable locking arm 84 and a pressed arm 85 that rotates the locking arm 84 in a direction away from the sheet restricting piece 80 when pressed.

[0046] The lock arm 84 is supported by a frame (not shown) so as to be rotatable in the R direction around the axis ε. Hereinafter, the rotation direction of the lock arm 84 approaching the sheet restricting piece 80 is referred to as the -R direction, and the rotation direction of the lock arm 84 moving away from the sheet restricting piece 80 is referred to as the +R direction (see FIG. 2). An engaging portion 86 that can engage with the engaged portion 83 of the sheet restricting piece 80 is provided at the tip of the lock arm 84. The engaging portion 86 is formed in a substantially pentagonal shape that protrudes in the circumferential direction from the lock arm 84 toward the sheet restricting piece 80 so as to form a V-shaped groove on the inside. The lock arm 84 is rotated toward the sheet restricting piece 80 (-R direction) so that the engaging portion 86 of the lock arm 84 engages with the engaged portion 83 of the sheet restricting piece 80.

[0047] The pressed arm 85 protrudes from the base end of the lock arm 84 in a direction approaching the sheet regulating piece 80 (-R direction) relative to the lock arm 84 (see Figs. 2 and 3). Therefore, when the pressed arm 85 is pressed in the +R direction, it rotates the lock arm 84 integrally in a direction away from the sheet regulating piece 80 (+R direction).

[0048] The stopper 81 interferes with the sheet regulating piece 80 via the lock arm 84 to regulate the rotation of the sheet regulating piece 80 (see FIG. 2). Specifically, when the lock arm 84 is rotated in a direction away from the sheet regulating piece 80 (in the +R direction), the engagement of the engaging portion 86 of the lock arm 84 with the engaged portion 83 of the sheet regulating piece 80 is released, and the regulation of the rotation of the sheet regulating piece 80 by the stopper 81 is released (see FIGS. 2 and 3).

[0049] By configuring the stopper 81 with such a lock arm 84, the rotation of the sheet restricting piece 80 can be easily restricted.

[0050] The stopper release portion 82 releases the restriction of the rotation of the sheet regulating piece 80 by the stopper 81. In this embodiment, the stopper release portion 82 is composed of a pressing protrusion 87 attached to the roller holder 7. Specifically, the stopper release portion 82a of the front sheet regulating portion 8a is composed of a pressing protrusion 87a attached to the outer surface of the front roller holder 7a adjacent to the front sheet regulating portion 8a, and the stopper release portion 82b of the rear sheet regulating portion 8b is composed of a pressing protrusion 87b attached to the outer surface of the rear roller holder 7b adjacent to the rear sheet regulating portion 8b. The pressing protrusion 87 presses against the pressed arm 85 of the stopper 81 in the +R direction in accordance with the swing of the pickup roller 60 in the +Q direction by the roller holder 7. When pressed by the pressing protrusion 87, the pressed arm 85 rotates the lock arm 84 in the +R direction, that is, in the direction to release the restriction on the rotation of the sheet regulating piece 80 (see Figs. 2 and 3). In this way, the stopper release portion 82 formed by the pressing protrusion 87 releases the restriction on the rotation of the sheet regulating piece 80 by the stopper 81.

[0051] In this way, by using a structure in which the lock arm 84 is rotated via the pressed arm 85 by the pressing protrusion 87 attached to the roller holder 7, the restriction on the rotation of the sheet regulating piece 80 by the stopper 81 can be released with a simple structure utilizing the roller holder 7.

[0052] The operation of each component of the sheet regulating section 8 can be summarized as follows. First, when the stopper 81 interferes with the sheet regulating piece 80 by the lock arm 84 and regulates the rotation of the sheet regulating piece 80, the sheet regulating piece 80 blocks the sheet placed on the manual feed tray 42 and regulates the position of the leading edge of the sheet (see FIG. 2). When the roller holder 7 swings the pickup roller 60 in the +Q direction, the stopper release section 82 formed of the pressing protrusion 87 starts pressing the pressed arm 85 of the stopper 81. Pressed by the stopper release section 82, the pressed arm 85 rotates the lock arm 84 in the +R direction. As the lock arm 84 rotates in the +R direction, the engagement of the lock arm 84 with the sheet regulating piece 80 is released, and the regulation of the rotation of the sheet regulating piece 80 by the stopper 81 is released. When the rotation of the sheet regulating piece 80 is released, the sheet regulating piece 80 receives pressure from the sheets including the top sheet pulled out by the pickup roller 60 and becomes rotatable toward the supply roller 61, allowing the passage of the sheets placed on the manual feed tray 42 (see FIG. 3). In this way, the sheet regulating section 8 switches between the blocked state and the blocked state when the stopper 81 receives pressure from the pressing protrusion 87 (stopper release section 82) attached to the roller holder 7 due to the swinging of the pickup roller 60 by the roller holder 7.

[0053] By configuring the sheet restricting portion 8 having the sheet restricting piece 80, the stopper 81, and the stopper release portion 82 as described above, it is possible to realize the sheet restricting portion 8 that switches and blocks the passage of the sheets with a simple structure.

[0054] Fig. 4 is a partially cutaway front view showing a state in which the stopper release portion 82a of the front sheet restricting portion 8a starts to press against the stopper 81a, as viewed from the front. Fig. 5 is a partially cutaway rear view showing a state in which the stopper release portion 82b of the rear sheet restricting portion 8b starts to press against the stopper 81b, as viewed from the rear.

[0055] The above-mentioned sheet regulating portions 8a, 8b have a technical feature in that they are configured to switch the blocking state at different timings. In this embodiment, in order to realize this, the stopper release portions 82a, 82b are configured to release the restriction of the rotation of the sheet regulating pieces 80a, 80b by the stoppers 81a, 81b at different timings. Specifically, this is as follows.

[0056] In this embodiment, the pressing protrusions 87a, 87b constituting the stopper release parts 82a, 82b of the sheet regulating parts 8a, 8b are arranged on the roller holders 7a, 7b so as to start pressing the pressed arms 85a, 85b of the stoppers 81a, 81b of the sheet regulating parts 8a, 8b at different timings. The pressing protrusion 87a is arranged at the upper end of the front roller holder 7a (see FIG. 4), and the pressing protrusion 87b is arranged in the vicinity of the support shaft 64 of the supply roller 61 in the rear roller holder 7b (see FIG. 5).

[0057] More specifically, the pressing protrusion 87a constituting the stopper release portion 82a is disposed on the roller holder 7a so as to start pressing against the pressed arm 85a of the stopper 81a in the front sheet regulating portion 8a when the angle θ1 between the imaginary straight line L passing through the axis of the supply roller 61 and the axis of the pickup roller 60 and the horizontal line becomes approximately 11.6 degrees as the roller holder 7 swings the pickup roller 60 in the +Q direction (see FIG. 4). On the other hand, the pressing protrusion 87b constituting the stopper release portion 82b is disposed on the roller holder 7b so as to start pressing against the pressed arm 85b of the stopper 81b in the rear sheet regulating portion 8b when the angle θ2 between the imaginary straight line L and the horizontal line becomes approximately 16.5 degrees as the roller holder 7 swings the pickup roller 60 in the +Q direction (see FIG. 5).

[0058] Due to such an arrangement of the pressing protrusions 87a and 87b, the pressing protrusion 87b starts pressing the pressed arm 85b of the stopper 81b before the pressing protrusion 87a starts pressing the pressed arm 85a of the stopper 81a in response to the swinging of the pickup roller 60 in the +Q direction by the roller holder 7. Therefore, the lock arm 84b rotates to release the restriction on the rotation of the rear sheet regulating piece 80b before the lock arm 84a rotates to release the restriction on the rotation of the front sheet regulating piece 80a. That is, the blocking state of the sheet regulating part 8b is switched before the blocking state of the sheet regulating part 8a is switched. In this way, the sheet regulating parts 8a and 8b are switched to their blocking states at different times by receiving the reaction force of the swinging of the pickup roller 60 by the roller holder 7 at the stoppers 81a and 81b.

[0059] As a result, the timing at which the roller holder 7 applies force to the sheet regulating portion 8a and the timing at which the roller holder 7 applies force to the sheet regulating portion 8b are shifted from each other, so that the load on the roller holder 7 can be distributed over time.

[0060] In this embodiment, as the roller holder 7 swings the pickup roller 60 in the +Q direction, a force is applied to the stopper 81b by the pressing protrusion 87b (stopper release portion 82b) attached to the roller holder 7, and then a force is applied to the stopper 81a by the pressing protrusion 87a (stopper release portion 82a) attached to the roller holder 7. This makes it possible to distribute the load on the pressing protrusions 87a, 87b (stopper release portions 82a, 82b) attached to the roller holder 7 over time.

[0061] Furthermore, as described above, by arranging the pressing protrusions 87a, 87b on the roller holder 7a or the roller holder 7b so that the pressing protrusions 87a, 87b begin to press the pressed arms 85a, 85b at different timings, the timing at which force is applied from the roller holder 7 to the sheet regulating portion 8a and the timing at which force is applied by the roller holder 7 to the sheet regulating portion 8b can be easily shifted from each other.

[0062] In this embodiment, among the pressing protrusions 87a, 87b constituting the stopper release portions 82a, 82b of the sheet regulating portions 8a, 8b, the pressing protrusion 87b that starts pressing the pressed arm 85b first is disposed on the roller holder 7b so as to press the pressed arm 85b at a position farther away from the rotation fulcrum of the pressed arm 85b than the pressing protrusion 87a (see Figs. 4 and 5). Specifically, the pressing protrusion 87b is disposed on the roller holder 7b so that the distance between the pressing point at which the pressing protrusion 87b presses the pressed arm 85b and the rotation fulcrum of the pressed arm 85b is greater than the distance between the pressing point at which the pressing protrusion 87a presses the pressed arm 85a and the rotation fulcrum of the pressed arm 85a. Therefore, the force with which the pressing protrusion 87b must press the pressed arm 85b to rotate the lock arm 84b is reduced by the principle of leverage, compared to the force with which the pressing protrusion 87a must press the pressed arm 85a to rotate the lock arm 84a. Therefore, the lock arm 84b, which rotates prior to the lock arm 84a, can be rotated with a lighter force than the lock arm 84a. As a result, the restriction on the rotation of the rear sheet restricting piece 80b, the restriction on the rotation of which is released prior to the front sheet restricting piece 80a, can be released with a lighter force than the front sheet restricting piece 80a, and thus the blocked state of the sheet restricting portions 8a, 8b can be switched more smoothly.

[0063] In addition, the pressing protrusion 87b is disposed on the roller holder 7b so that the distance between the pressing protrusion 87b and the pivot 64, which is the pivot point of the roller holder 7, is smaller than the distance between the pressing protrusion 87a and the pivot 64 (see Figs. 4 and 5). Therefore, the force with which the pressing protrusion 87b presses the pressed arm 85b as the roller holder 7 rotates is greater than the force with which the pressing protrusion 87a presses the pressed arm 85a as the roller holder 7 rotates. Therefore, compared to the case where the pressing protrusion 87b presses the pressed arm 85a when the lock arm 84a rotates, the pressing protrusion 87b can be pressed against the pressed arm 85b more efficiently when the lock arm 84b rotates. This allows the lock arm 84b to rotate more efficiently than the lock arm 84a.

[0064] In addition, in this embodiment, an additional pressing protrusion 88 is provided on the inside of the rear roller holder 7b, which can continue to press against the pressed arm 85b after the pressing protrusion 87b constituting the stopper release portion 82b starts pressing against the pressed arm 85b of the stopper 81b (see Figure 5).

[0065] When such an additional pressing protrusion 88 presses against the pressed arm 85b, the lock arm 84b is rotated, and the restriction on the rotation of the rear sheet restricting piece 80b can be reliably released.

[0066] The configuration of the roller holder 7 is not limited to the above, and may be, for example, formed in a box shape that is open at the bottom.

[0067] Furthermore, the configuration of the sheet regulating unit 8 is not limited to the above, and it is sufficient if the sheet restraining unit 8 can switchably block the passage of the placed sheets in conjunction with the swinging of the pickup roller 60 by the roller holder 7. For example, the stopper release unit 82 may be separately provided to be rotatable and may be linked to the swinging of the pickup roller 60 by the roller holder 7.

[0068] The sheet supplying device 6 can be used not only to feed a sheet from the manual feed tray 42 to the sheet transport path S, but also to feed a sheet from the automatic document processing device 12 to the document reading device 10.

[0069] (Embodiment 2) Hereinafter, the second embodiment will be described only with respect to the points different from the first embodiment.

[0070] In the second embodiment, the stoppers 81a, 81b in the sheet regulating portions 8a, 8b are configured to interfere with the sheet regulating pieces 80a, 80b by their own weights with the lock arms 84a, 84b, respectively, to regulate the rotation of the sheet regulating pieces 80a, 80b. Specifically, the weight balance of the lock arm 84 and the pressed arm 85 is adjusted so that the engaging portion 86 of the lock arm 84 engages with the engaged portion 83 of the sheet regulating piece 80 by its own weight.

[0071] This makes it possible to regulate the rotation of the sheet regulating piece 80 without providing a separate structure for rotating the lock arm 84 toward the sheet regulating piece 80 (-R direction), thereby reducing the cost of the sheet supply device and making it easier to assemble.

[0072] In this embodiment, the stoppers 81a, 81b in the sheet regulating portions 8a, 8b are configured to interfere with the sheet regulating pieces 80a, 80b by the lock arms 84a, 84b to regulate the rotation of the sheet regulating pieces 80a, 80b when the pressed arms 85a, 85b are released from the pressure of the pressing protrusions 87a, 87b. Specifically, when the roller holder 7 swings the pickup roller 60 in a direction away from the manual feed tray 42 (-Q direction), the pressing protrusion 87 leaves the pressed arm 85, and the pressed arm 85 is released from the pressure of the pressing protrusion 87. The weight balance of the lock arm 84 and the pressed arm 85 is adjusted so that the engagement portion 86 of the lock arm 84 engages with the engagement portion 83 of the sheet regulating piece 80 when the pressed arm 85 is released from the pressure of the pressing protrusion 87.

[0073] This makes it possible to restrict the rotation of the sheet regulating piece 80 without providing a separate structure for returning the lock arm 84 to the state in which the rotation of the sheet regulating piece 80 is restricted, thereby reducing the cost of the sheet supply device 6 and facilitating its assembly.

[0074] (Embodiment 3) Hereinafter, the third embodiment will be described only with respect to the points different from the first embodiment.

[0075] Fig. 6 is a partially cutaway front view showing a state in which the stopper release portion 82a of the front sheet restricting portion 8a starts to press against the stopper 81a in the third embodiment, as viewed from the front. Fig. 7 is a partially cutaway rear view showing a state in which the stopper release portion 82b of the rear sheet restricting portion 8b starts to press against the stopper 81b in the third embodiment, as viewed from the rear.

[0076] In the third embodiment, the pressing protrusions 87a and 87b constituting the stopper release parts 82a and 82b are respectively arranged on the roller holders 7a and 7b symmetrically in the front-rear direction (see Figs. 6 and 7). In this embodiment, the locking arms 84a and 84b and the pressed arms 85a and 85b in the stoppers 81a and 81b are formed so that the pressing protrusions 87a and 87b start pressing the pressed arms 85a and 85b at different timings. Specifically, the angle ω2 between the locking arm 84b and the pressed arm 85b in the stopper 81b is larger than the angle ω1 between the locking arm 84a and the pressed arm 85a in the stopper 81a (see Figs. 6 and 7). In this embodiment, the angle ω1 is set to about 97 degrees, and the angle ω2 is set to about 103 degrees. Due to such a difference between the angles ω1 and ω2, the pressing protrusion 87b starts pressing the pressed arm 85b of the stopper 81b before the pressing protrusion 87a starts pressing the pressed arm 85a of the stopper 81a as the roller holder 7 swings the pickup roller 60 in the +Q direction. Therefore, the lock arm 84b rotates to release the restriction on the rotation of the rear sheet regulating piece 80b before the lock arm 84a rotates to release the restriction on the rotation of the front sheet regulating piece 80a. In other words, the blocking state of the sheet regulating portion 8b is switched before the blocking state of the sheet regulating portion 8a is switched.

[0077] In this way, by adjusting the angle ω1 between the lock arm 84a and the pressed arm 85a and the angle ω2 between the lock arm 84b and the pressed arm 85b, the timing at which force is applied from the roller holder 7 to the sheet regulating portion 8a and the timing at which force is applied by the roller holder 7 to the sheet regulating portion 8b can be easily shifted from each other.

[0078] The above-mentioned embodiments and examples are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-mentioned embodiments and examples, but is defined based on the claims. In addition, all modifications within the meaning and scope of the claims are included. [Explanation of symbols]

[0079] A Image forming device B. Image forming device main body 1 Image reading unit 2 Image forming section 3 Intermediate transfer body 5 Sheet roller group 6 Sheet Feeder 60 Pickup roller 61 Supply roller 62 Separation roller 63 Drive belt 64 Spindle 7(7a,7b) Roller holder 8(8a,8b) Seat regulating part 80 Seat Regulation Strip 81 Stopper 82 Stopper release part 83 Engaged part 84 Lock Arm 85 Pressed arm 86 Engagement part 87 Pressing protrusion 88 Additional pressing protrusion S Sheet transport path

Claims

1. A sheet feeding device including a pickup roller for picking up a top sheet of stacked sheets, A roller holder supported pivotally so as to be swingable; A pickup roller journaled by the roller holder; a pair of sheet regulating portions provided on both sides of the roller holder in a rotational axis direction of the pickup roller, the pair of sheet regulating portions switchably block a passage through which the placed sheets pass, The sheet supplying device according to claim 1, wherein the pair of sheet regulating portions are configured to switch between blocking states at different timings when the roller holder is swung.

2. 2. The sheet feeding apparatus according to claim 1, The pair of sheet regulating portions each include A sheet regulating piece that is rotatably provided; a stopper capable of restricting the rotation of the sheet restricting piece; a stopper release portion that releases the restriction of the stopper against the rotation of the sheet restricting piece, The sheet supplying device according to claim 1, wherein the stopper release portion of each of the pair of sheet regulating portions is configured to release the regulation by the stopper at different timings.

3. 3. The sheet feeding device according to claim 2, The stoppers of the pair of sheet regulating portions each have a rotatable lock arm, The lock arm interferes with the sheet regulating piece to regulate the rotation of the sheet regulating piece.

4. 4. The sheet feeding apparatus according to claim 3, The sheet supplying device according to claim 1, wherein the stoppers of the pair of sheet regulating portions rotate under their own weight.

5. 5. The sheet feeding device according to claim 3, further comprising: The stoppers of the pair of sheet regulating portions each have a pressed arm that is pressed to rotate the lock arm in a predetermined direction, the stopper release portions of the pair of sheet regulating portions are each formed of a pressing protrusion attached to the roller holder, The sheet supplying device according to claim 1, wherein the pressing protrusion presses the pressed arm to release the restriction of the stopper when the roller holder swings.

6. 6. The sheet feeding apparatus according to claim 5, a pair of sheet regulating portions each having a pressing protrusion disposed on the roller holder so as to press the pressed arm at a timing different from each other, the pair of sheet regulating portions comprising: a pair of sheet regulating portions each having a pressing protrusion disposed on the roller holder;

7. 7. The sheet feeding apparatus according to claim 6, a pressing protrusion in each of the pair of sheet regulating portions that first starts to press the pressed arm is arranged on the roller holder so as to press the pressed arm at a position farther from the pivot point of the pressed arm than the other pressing protrusion.

8. A sheet feeding device according to any one of claims 5 to 7, A sheet supplying device characterized in that the stoppers in the pair of sheet regulating portions each interfere with the sheet regulating piece with the lock arm when the pressed arm is released from the pressure from the pressing protrusion, thereby regulating the rotation of the sheet regulating piece.

9. 9. An image forming apparatus comprising the sheet supplying device according to claim 1.

Images