Sheet feeding device and image forming apparatus including the same

Abstract

The invention provides a sheet supply device and an image forming apparatus. The sheet supply device includes a sheet storage portion that stores a sheet. The sheet storage portion includes a bottom wall portion and a peripheral wall portion. The sheet stacking plate includes a plate-shaped base portion, a support sheet, and a protrusion portion. The protrusions protrude axially outward from the upper ends of the support pieces. The peripheral wall portion has a pair of support protrusions and a groove portion. The pair of support protrusions protrude from both inner peripheral surfaces facing each other in the axial direction of the rotating shaft, pass through the through hole, and rotatably support the sheet stacking plate. The groove portions are recessed axially outward from two inner circumferential surfaces facing each other in the axial direction of the rotating shaft, and extend in the rotation direction of the protrusion portion. When the sheet stacking plate ascends, the protruding portion is arranged inside the groove portion.

Description

Technical Field

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

[0002] The existing sheet feeding device includes a sheet storage part, a sheet stacking plate and a lifting mechanism. The sheet storage part is used to store sheets. The sheet stacking plate is supported to be able to rotate in the upward and downward directions around a rotation axis arranged at the end of the upstream side of the sheet conveying direction. The lifting mechanism raises and lowers the sheet stacking plate. The highest sheet stacked on the sheet stacking plate is fed in sequence.

[0003] In the case of the prior art, when the sheet stacking plate is subjected to an impact such as falling during transportation, there is a possibility that the sheet stacking plate will fall off from the sheet storage portion. In this case, there is a problem that the operation of attaching the sheet stacking plate to the sheet storage portion is increased when opening the package, thereby reducing convenience. In addition, when the sheet stacking plate is fixed to the sheet storage portion with packaging materials such as tape, there is a problem that the operation of removing the packaging materials is increased when opening the package, thereby reducing convenience. In addition, there is a problem of increased garbage volume. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide a sheet feeding device and an image forming apparatus equipped with the same, which can reduce the amount of waste and improve the convenience when opening.

[0005] A sheet feeding device according to one embodiment of the present invention includes a sheet storage portion for storing sheets, a sheet stacking plate, and a lifting mechanism. The sheet stacking plate is supported so as to be rotatable in the upward and downward directions around a rotation axis disposed at an end portion on the upstream side of the sheet conveying direction. The lifting mechanism raises and lowers the sheet stacking plate. The sheet storage portion includes a bottom wall portion and a peripheral wall portion. The bottom wall portion supports the sheet stacking plate. The peripheral wall portion protrudes upward from a peripheral edge portion of the bottom wall portion and surrounds the bottom wall portion. The sheet stacking plate includes a plate-shaped base portion, a supporting sheet, and a protruding portion. The base portion is disposed on the bottom wall portion and is used for stacking sheets. The supporting sheet protrudes upward from both axial ends of the base portion and has a through hole penetrating in the axial direction. The protruding portion protrudes axially outward from the upper end portion of each supporting sheet. The peripheral wall portion includes a pair of supporting protrusions and a groove portion. A pair of supporting protrusions protrude from two inner peripheral surfaces opposite to each other in the axial direction of the rotating shaft, penetrate through the through hole, and support the sheet stacking plate to be rotatable. The groove is recessed from the two inner peripheral surfaces opposite to each other in the axial direction of the rotating shaft toward the axial outer side, and extends along the rotation direction of the protrusions. When the sheet stacking plate rises, the protrusions are arranged inside the grooves.

[0006] According to a sheet feeding device of one embodiment of the present invention, it is possible to provide a sheet feeding device capable of reducing the amount of waste and improving the convenience when opening a sheet, and an image forming apparatus including the same.

[0007] Other objects of the present invention and specific advantages obtained by the present invention are further reflected from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a cross-sectional view showing the internal structure of an image forming apparatus 100 according to one embodiment of the present invention. Figure 2 It is a perspective view showing a sheet feeding device 1 a of the image forming apparatus 100 according to one embodiment of the present invention. Figure 3 It is a perspective view showing the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. Figure 4 It is a side cross-sectional view showing the peripheral structure of the lift mechanism 30 of the image forming apparatus 100 according to one embodiment of the present invention. Figure 5 This is a perspective view showing an enlarged view of the periphery of the support piece 22 of the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. Figure 6 This is a perspective view showing an enlarged view of the periphery of the support piece 22 of the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. Figure 7 This is an enlarged longitudinal sectional view showing the periphery of the support piece 22 of the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. Figure 8 This is an enlarged longitudinal sectional view showing the periphery of the support piece 22 of the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. Fig. 9 This is a perspective view showing an enlarged view of the periphery of the support piece 22 of the sheet stacking plate 20 of the image forming apparatus 100 according to one embodiment of the present invention. DETAILED DESCRIPTION

[0009] <Configuration of Image Forming Apparatus 100 > Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 1 is a cross-sectional view showing the internal structure of an image forming apparatus 100 according to an embodiment of the present invention. In addition, the solid arrows in the figure represent the conveyance path and conveyance direction of paper.

[0010] The image forming apparatus 100 includes a cassette mounting portion 101, paper supply units 117a, 117b, a manual tray 102, a paper conveying portion 103, a document conveying device 104, an image reading portion 105, an image forming portion 106, a transfer portion 107, a fixing portion 108, a discharge bifurcation portion 109, a double-sided printing unit 110, and a control portion 120.

[0011] The cassette mounting portion 101 is disposed at the lower portion of the image forming apparatus 100. Two sheet feeding devices 1a and 1b are mounted in the cassette mounting portion 101. The sheet feeding devices 1a and 1b stack and store a bundle of paper (sheets) P ​​before printing.

[0012] The paper feeding units 117a and 117b feed sheets P one by one from a bundle of sheets P. The paper feeding unit 117a includes a pickup roller 129a and a pair of paper feeding rollers 130a provided corresponding to the sheet feeding device 1a. The paper feeding unit 117b includes a pickup roller 129b and a pair of paper feeding rollers 130b provided corresponding to the sheet feeding device 1b.

[0013] The manual tray 102 is provided outside the upper right side of the image forming apparatus 100. The manual tray 102 carries paper, OHP sheets, envelopes, postcards, invoices, etc. of different sizes and thicknesses from the sheets P in the sheet feeding devices 1a and 1b.

[0014] The paper conveying unit 103 is located on the downstream side in the sheet conveying direction, i.e., on the right side, relative to the cassette mounting unit 101, and is located on the downstream side in the sheet conveying direction, i.e., on the left side, relative to the manual feed tray 102. The sheet P fed from the sheet feeding devices 1a and 1b is conveyed vertically upward along the side surface of the image forming apparatus 100 main body by the paper conveying unit 103, and the sheet P fed from the manual feed tray 102 is conveyed horizontally.

[0015] The document feeding device 104 is arranged on the upper surface of the image forming apparatus 100, and the image reading unit 105 is arranged below the document feeding device 104. When copying documents, the user places a plurality of documents on the document feeding device 104. The document feeding device 104 feeds the documents one by one, and the image reading unit 105 reads the image data thereof.

[0016] The image forming section 106 and the transfer section 107 are arranged on the downstream side of the paper conveying direction of the paper conveying section 103 and below the image reading section 105. In the image forming section 106, an electrostatic latent image of the original image is formed based on the image data read by the image reading section 105, and the electrostatic latent image is developed to form a toner image. On the other hand, in synchronization with the formation timing of the toner image in the image forming section 106, the sheet P is conveyed to the transfer section 107 from the sheet feeding devices 1a and 1b via the registration roller pair 119 of the paper conveying section 103. The toner image formed in the image forming section 106 is transferred onto the sheet P in the transfer section 107.

[0017] The fixing section 108 is arranged on the downstream side of the transfer section 107. The sheet P to which the unfixed toner image is transferred in the transfer section 107 is conveyed to the fixing section 108. The fixing section 108 has a slit section of a fixing roller pair composed of a heating roller and a pressure roller. The unfixed toner image is fixed on the sheet P as the sheet P passes through the slit section.

[0018] The discharge branching portion 109 is disposed downstream of the fixing portion 108 and near the left side of the image forming apparatus 100. When double-sided printing is not performed, the sheet P discharged from the fixing portion 108 is discharged from the discharge branching portion 109 to a paper discharge tray 111 disposed outside the left side of the image forming apparatus 100.

[0019] The duplex printing unit 110 is disposed above the cassette mounting portion 101. When duplex printing is performed, the sheet P discharged from the fixing portion 108 is sent to the duplex printing unit 110 via the discharge branch portion 109. The sheet P sent to the duplex printing unit 110 is switched back so as to be turned over and passed through the paper conveying portion 103 again, and is conveyed to the transfer portion 107 with the surface on which an image is not formed facing upward.

[0020] The control unit 120 controls the driving of each unit constituting the image forming apparatus 100 , such as the cassette mounting unit 101 , the paper conveying unit 103 , the image reading unit 105 , the image forming unit 106 , the transfer unit 107 , and the fixing unit 108 .

[0021] <Configuration of Sheet Feeding Device 1 a > Figure 2 is a perspective view of the sheet feeding device 1a. Figure 3 It is a perspective view of the sheet stacking plate 20 . Figure 4 It is a side cross-sectional view showing the peripheral structure of the lifting mechanism 30 of the sheet stacking plate 20 of the sheet feeding device 1a. In addition, although the structure of the sheet feeding device 1a is described here, the structure of the sheet feeding device 1b is exactly the same.

[0022] In the figure, the insertion direction of the sheet feeding device 1a with respect to the cassette mounting portion 101 is indicated by an arrow X1, and the extraction direction is indicated by an arrow X2, and the sheet conveying direction of the sheet feeding device 1a coincides with the insertion direction X1 of the sheet feeding device 1a. In addition, the axial direction (Y1-Y2) of the rotation axis C coincides with the width direction of the sheet P and the front-rear direction of the image forming apparatus 100. In the present embodiment, the sheet conveying direction (X1-X2 direction), the axial direction (Y1-Y2 direction), and the up-down direction (Z1-Z2 direction) are perpendicular to each other.

[0023] The sheet feeding device 1a is mounted on the cassette mounting portion 101. A paper feeding unit 117a (see Figure 1 ), sheet body P (refer to Figure 1 The sheet feeding device 1 a includes a sheet storage portion 10 , a sheet stacking plate 20 , a stopper 7 , and a lift mechanism 30 .

[0024] The sheet storage section 10 is in a box shape with an open top surface. The sheet storage section 10 stores stacked sheets P therein. The sheet storage section 10 includes a bottom wall section 11 and a peripheral wall section 12. The bottom wall section 11 is formed in a rectangular shape in a plan view.

[0025] The peripheral wall portion 12 protrudes from the peripheral edge portion of the bottom wall portion 11 toward the upper side Z1 and is formed in an annular shape. A pair of supporting protrusions 121 are formed on each inner peripheral surface of the peripheral wall portion 12 that is opposite in the axial direction (Y1-Y2 direction) of the rotation axis C. The supporting protrusions 121 are formed to protrude from the inner peripheral surface of the peripheral wall portion 12 toward the axial direction (Y1-Y2 direction).

[0026] The sheet stacking plate 20 is supported to be rotatable in the vertical direction around a rotation axis C disposed at an end portion on the upstream side X2 in the sheet conveying direction. The sheet stacking plate 20 includes a base portion 21 and a support piece 22. The base portion 21 is a plate-shaped member for stacking sheets P, and is disposed on the bottom wall portion 11. At the end portion on the upstream side X2 in the sheet conveying direction of the base portion 21, a support piece 22 is disposed at each of the two ends in the axial direction (Y1-Y2 direction).

[0027] The support piece 22 protrudes from the upper surface of the base portion 21 toward the upper side Z1 and is formed in a plate shape. The support piece 22 is arranged in a direction perpendicular to the axial direction (Y1-Y2 direction) and parallel to the peripheral wall portion 12. Each support piece 22 has a through hole 221 that penetrates in the axial direction (Y1-Y2 direction). The lower end of the through hole 221 extends across the base portion 21. Therefore, the inner end of the through hole 221 in the axial direction (Y1-Y2 direction) is closer to the inner side in the axial direction (Y1-Y2 direction) than the inner end of the support piece 22 in the axial direction (Y1-Y2 direction). The support protrusion 121 passes through the interior of the through hole 221. In this way, the end of the downstream side (X1 direction) of the sheet conveying direction of the sheet stacking plate 20 is supported by the support protrusion 121.

[0028] The sheet stacking plate 20 is provided so that it can be lifted up and down relative to the sheet storage section 10 with the upper edge of the through hole 221 in contact with the supporting protrusion 121 as a fulcrum at the swing end 21a (the end on the downstream side X1 in the sheet conveying direction). In addition, the mounting structure of the sheet storage section 10 and the sheet stacking plate 20 will be described in detail later.

[0029] The stopper 7 is arranged on the upstream side X2 in the sheet conveying direction of the sheet stacking plate 20. The stopper 7 is provided on the bottom wall portion 11 so as to be movable back and forth in the sheet conveying direction (X1-X2 direction). The stopper 7 positions the end of the sheet P stacked on the sheet stacking plate 20 in the sheet conveying direction (X1-X2 direction).

[0030] The lifting mechanism 30 is arranged below the vicinity of the swing end 21a of the sheet stacking plate 20. The lifting mechanism 30 includes a swing shaft 31 and an operating plate 32. The swing shaft 31 extends in the sheet width direction (Y1-Y2 direction), and both ends of the swing shaft 31 are rotatably held by two bearings (not shown) formed on the bottom wall 11 of the sheet storage section 10. The axial end of the swing shaft 31 is connected to a lifting drive unit (not shown).

[0031] The base end portion of the operating plate 32 is fixed to the swing shaft 31. The operating plate 32 is disposed, for example, at a position facing a substantially central portion of the back surface of the sheet stacking plate 20 in the axial direction (Y1-Y2 direction).

[0032] When the swing shaft 31 is rotated by a lift drive unit (not shown), the operating plate 32 is also rotated. Thus, the sheet stacking plate 20 can be moved up and down between a raised position for supplying sheets P and a lowered position for placing (replenishing) sheets P.

[0033] <Attachment Structure of Sheet Storage Section 10 and Sheet Stacking Plate 20 >

[0034] Figure 5 and Figure 62 is a perspective view showing an enlarged view of the periphery of the support piece 22 of the sheet stacking plate 20. Figure 5 2 shows a state before the sheet stacking plate 20 is mounted on the sheet storage section 10. Figure 6 2 shows a state where the sheet stacking plate 20 is mounted on the sheet storage section 10. Figure 7 and Figure 8 2 is a longitudinal sectional view showing an enlarged view of the periphery of the support piece 22 of the sheet stacking plate 20. Figure 7 2 shows a state before the sheet stacking plate 20 is mounted on the sheet storage section 10. Figure 8 The state in which the sheet stacking plate 20 is attached to the sheet storage section 10 is shown.

[0035] The sheet stacking plate 20 has a protrusion 222 and a convex portion 223. The protrusion 222 protrudes outward in the axial direction (Y1-Y2 direction) from the upper end portion of the support piece 22.

[0036] The convex portion 223 protrudes outward in the axial direction (Y1-Y2 direction) from the lower end periphery of the through hole 221. More specifically, the convex portion 223 extends downward from the lower end periphery of the through hole 221, and the front end portion is bent outward in the axial direction (Y1-Y2 direction). In this way, the convex portion 223 is easily deformed, and the convex portion 223 absorbs the applied stress, thereby preventing the convex portion 223 from being damaged.

[0037] The support protrusion 121 has a stopper 121a and a rib 121b. The stopper 121a extends in the vertical direction from the front end of the support protrusion 121 in the axial direction (Y1-Y2 direction) and is formed in a plate shape. The stopper 121a is arranged parallel to the support piece 22. The lower end of the stopper 121a is located above the upper surface of the bottom wall 11, and a gap H is formed between the stopper 121a and the bottom wall 11 (see Figure 7 , Figure 8 ).

[0038] The rib 121b protrudes from the lower end of the locking portion 121a toward the inner side in the axial direction (Y1-Y2 direction) and extends in the sheet conveying direction (A1-A2 direction). The upper surface of the rib 121b is inclined downward as it moves from the lower end toward the inner side in the axial direction (Y1-Y2 direction). In this way, the convex portion 223 is smoothly guided toward the lower side Z2 by sliding on the upper surface of the rib 121b.

[0039] The peripheral wall portion 12 has groove portions 122a and 122b. The groove portions 122a and 122b are formed by being recessed outward in the axial direction (Y1-Y2 direction) from each inner peripheral surface of the peripheral wall portion 12 that is opposite in the axial direction (Y1-Y2 direction). The groove portion 122b extends from the root of the supporting protrusion 121 toward the upper side Z1, and the upper end is open. The groove portion 122a extends in the rotation direction (X1-X2) of the protrusion 222. In the present embodiment, the groove portion 122a extends from the lower end portion of the groove portion 122b to the rotation direction (X1-X2) of the protrusion 222. That is, the groove portion 122a branches from the groove portion 122b at the root of the supporting protrusion 121 and extends in the upward direction Z1.

[0040] When the sheet stacking plate 20 is mounted on the sheet storage section 10, the protrusion 222 is arranged in the groove 122b, and the sheet stacking plate 20 is pushed downward Z2. In this way, the protrusion 222 is guided along the groove 122b, and the support piece 22 moves smoothly toward the support protrusion 121 (see Figure 5 , Figure 7 ).

[0041] If the sheet stacking plate 20 is further pushed downward Z2, the protrusion 223 slides on the upper surface of the rib 121b. At this time, the locking portion 121a and the protrusion 223 are warped. The locking portion 121a and the protrusion 223 that were warped when the rib 121b was inserted into the gap H return to their original shapes. In addition, the upper end portion of the through hole 221 is supported on the supporting protrusion 121. In this way, the sheet stacking plate 20 is mounted on the sheet storage portion 10 and is supported by the supporting protrusion 121 so as to be rotatable with the rotation axis C as the center. When the sheet stacking plate 20 is raised or lowered, the protrusion 223 moves in the gap H in the sheet conveying direction (X1-X2 direction).

[0042] When the sheet stacking plate 20 is mounted on the sheet storage section 10, the upper side Z1 of the protrusion 223 is covered by the rib 121b. Thus, when the sheet stacking plate 20 is subjected to force in the upper side Z1 direction due to, for example, an impact during transportation, the protrusion 223 contacts the rib 121b. Thus, the sheet stacking plate 20 can be prevented from falling off the sheet storage section 10. Therefore, it is not necessary to fix the sheet stacking plate 20 to the sheet storage section 10 with packaging materials such as tape. Thus, a sheet supply device 1a can be provided that can reduce the amount of garbage and improve the convenience of opening.

[0043] Fig. 9This is a three-dimensional diagram showing the periphery of the support piece 22 of the sheet stacking plate 20 in an enlarged manner, and shows the state in which the sheet stacking plate 20 installed in the sheet storage section 10 is raised. When the sheet stacking plate 20 is raised, the protrusion 222 rotates around the rotation axis C, moves to the upstream side X2 in the sheet conveying direction, and is inserted into the groove 122a. On the other hand, the convex portion 223 rotates around the rotation axis C, and moves to the downstream side X1 in the sheet conveying direction. At this time, the convex portion 223 is offset to the downstream side X1 in the sheet conveying direction relative to the rib 121b.

[0044] Therefore, when the sheet stacking plate 20 is in the ascending state and receives a force in the upward Z1 direction, the protrusion 223 may fall off from the rib 121b. In the present embodiment, when the sheet stacking plate 20 is in the ascending state, the protrusion 222 is arranged inside the groove 122a. Therefore, the sheet stacking plate 20 can be further prevented from falling off from the sheet storage section 10.

[0045] In addition, all the contents of the embodiments of the present invention are illustrative and not restrictive. The scope of the present invention is not limited to the description of the above embodiments, but is indicated by the claims, and includes contents equivalent to the claims and all modifications within the scope of the claims.

[0046] For example, in the above embodiment, the lifting mechanism raises and lowers the sheet stacking plate 20 by rotating the operating plate 32, but it may be composed of other mechanisms. For example, the sheet stacking plate 20 may be raised and lowered by the pulling force of a coil spring. In addition, in the present embodiment, two sheet feeding devices 1a and 1b are provided, but one or more than three may be provided.

Claims

1. A sheet feeding device, characterized in that include: A sheet storage portion for storing sheets; The sheet stacking plate is supported to be rotatable in the vertical direction around a rotation shaft disposed at an end portion on the upstream side in the sheet conveying direction; as well as A lifting mechanism is used to raise and lower the sheet stacking plate. The sheet storage portion includes: A bottom wall portion, supporting the sheet stacking plate; and a peripheral wall portion, which protrudes upward from a peripheral edge portion of the bottom wall portion and surrounds the bottom wall portion, The sheet stacking plate comprises: A plate-shaped base portion, arranged on the bottom wall portion, for stacking the sheets; a support piece protruding upward from both axial ends of the base portion and having a through hole penetrating in the axial direction; and A protrusion protrudes axially outward from the upper end of each of the support pieces, The peripheral wall portion comprises: a pair of supporting protrusions, which protrude from two inner peripheral surfaces opposite to each other in the axial direction of the rotating shaft and penetrate through the through hole to rotatably support the sheet stacking plate; and The groove portion is recessed from two inner circumferential surfaces opposite to each other in the axial direction of the rotating shaft toward the axially outer side and extends along the rotation direction of the protrusion portion. When the sheet stacking plate is raised, the protrusion is arranged inside the groove.

2. The sheet feeding device according to claim 1, wherein: The support protrusion comprises: A locking portion extending in the up-down direction from the front end portion in the axial direction; and A rib protruding axially inward from the lower end of the locking portion, The sheet stacking plate has a convex portion protruding axially outward from the lower end peripheral edge of the through hole. The protrusion is arranged in a gap between the rib and the bottom wall in the vertical direction.

3. The sheet feeding device according to claim 2, wherein: The upper surface of the rib is inclined downward toward the axial inner side.

4. The sheet feeding device according to claim 3, wherein: The convex portion extends downward from the lower end periphery of the through hole and has a front end portion bent axially outward.

5. The sheet feeding device according to claim 1 or 2, characterized in that: The groove portion diverges at a root portion of the supporting protrusion and extends in an upward direction.

6. An image forming device, characterized in that include: The sheet feeding device according to claim 1 or claim 2; as well as An image forming unit that forms an image on a sheet.

Images