Sheet feeding device

Abstract

To provide an image forming device capable of preventing a sheet from rotating due to impact when inserting sheet storage means.SOLUTION: A rear side regulation member 80 and a front side regulation member 81 which are provided upstream in a sheet feed direction from a rear side regulation plate 61 and a front side regulation plate 62 regulate a widthwise side edge position of a sheet of a predetermined size stored in a paper feed cassette 60. When a small size S3 sheet which is shorter in width than the sheet of the predetermined size is stored in the paper feed cassette 60, an auxiliary side regulation member 82 is attached to the rear side regulation member 80 and the front side regulation member 81 to regulate the side edge position in the width direction of the small size sheet S3.SELECTED DRAWING: Figure 5

Description

Technical Field

[0005] , , , , , ,

[0001] The present invention Sheet feeding device for feeding sheets relates to a configuration for regulating the position of a sheet, particularly.

Background Art

[0002] Today, in image forming apparatuses such as copiers, printers, facsimiles, etc., those configured to feed a sheet stored in a sheet storage means to an image forming section to form an image are widely spread. As such a sheet storage means, there is one provided with a plate-like sheet loading means for loading sheets so as to be movable up and down.

[0003] When replenishing the sheet, the sheet loading means is lowered, and when feeding the sheet, the sheet loading means is raised to move the upper surface of the loaded sheet to a position where it can be fed by an upper pickup roller. Further, the sheet storage means is provided so as to be pullable out of the apparatus main body, and when storing the sheet, after pulling out the sheet storage means, the sheet is set on the sheet loading means from above.

[0004] In the sheet storage means, a rear end regulating means for regulating the position of the upstream end in the sheet feeding direction (hereinafter referred to as the rear end) of the sheet loaded on the sheet loading means so as to be able to store sheets of different sizes is provided so as to be movable along the sheet feeding direction. Further, in the sheet storage means, a side end regulating means for regulating the side end position of the sheet in the direction orthogonal to the sheet feeding direction (hereinafter referred to as the width direction) is provided so as to be movable in the width direction. And, by regulating the side end of the sheet by the side end regulating means and regulating the rear end of the sheet by the rear end regulating means, the position of the sheet is regulated to a predetermined position (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] By the way, if the paper cassette is subjected to an impact when inserting it, the sheet will rotate. As a result, the sheet will shift inside the paper cassette, causing the image on the sheet to shift by the same amount, or the sheet to become skewed, resulting in the image being formed at an angle.

[0007] Therefore, the present invention has been made in view of the current situation, and can prevent the seat from rotating due to impact when inserting the seat storage means. Sheet feeding device The purpose is to provide [something]. [Means for solving the problem]

[0008] One aspect of the present invention involves storing a sheet , equipped It is detachably attached to the main body and is inserted in the insertion direction, so that it is forward Recording A seat storage mechanism attached to the main unit, and the front Recording The sheet storage means, which is mounted on the main body, feeds the sheet stored in it in a direction perpendicular to the insertion direction by a roller positioned on the leading edge of the sheet; a side edge regulating means provided on the sheet storage means so as to be movable in the sheet width direction parallel to the insertion direction and regulating the position of the side edge of the sheet; a rear edge regulating means provided on the sheet storage means so as to be movable in a direction perpendicular to the insertion direction and regulating the position of the rear edge of the sheet by contacting the center of the rear edge of the sheet in the sheet width direction; and an auxiliary regulating means that is detachable from the sheet storage means, is attached to a predetermined position when a sheet of a specific size is stored, and contacts the downstream side edge of the sheet of the specific size in the insertion direction, wherein the auxiliary regulating means is detachable from the sheet storage means independently of the rear edge regulating means, the rear edge regulating means is movable independently of the auxiliary regulating means, the predetermined position is on the rear edge side of the sheet of the specific size from the side edge regulating means, and the auxiliary regulating means is attached to the predetermined position. Before The means for storing the sheet is in front RecordingInsert into the main body in the aforementioned insertion direction be In this process, the auxiliary restricting means is characterized by contacting the rear end of the sheet of the specified size, thereby restricting the rear end of the sheet of the specified size from moving downstream in the insertion direction. Sheet feeding It is a device. [Effects of the Invention]

[0009] According to the present invention, it is possible to prevent the sheet from rotating. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a schematic configuration of a full-color laser beam printer, which is an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] This diagram illustrates the configuration of the mounting section of the full-color laser beam printer described above and the paper feed cassette that is detachably attached to the mounting section. [Figure 3] A diagram illustrating the configuration of the front side restricting member provided on the above-mentioned paper feed cassette. [Figure 4] This diagram illustrates the process of attaching an auxiliary side restricting member to the front side restricting member shown above. [Figure 5] This diagram shows the state when different sized sheets are stored in the paper feed cassette mentioned above. [Figure 6] A diagram showing the configuration of a conventional paper feed cassette. [Modes for carrying out the invention]

[0011] Hereinafter, an example of the sheet feeding device of the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram showing the schematic configuration of a full-color laser beam printer, which is an example of an image forming apparatus according to an embodiment of the present invention. In Figure 1, 1 is a full-color laser beam printer (hereinafter referred to as the printer), 1A is the printer body which is the main body of the image forming apparatus, 1B is the image forming unit which forms an image on a sheet, and 20 is the fixing unit. 2 is an image reading device which is an upper device installed substantially horizontally above the printer body 1A, and an discharge space P is formed between this image reading device 2 and the printer body 1A. 30 is a sheet feeding device provided at the bottom of the printer body 1A, and 15 is a toner cartridge.

[0012] Image information read by the image reading device 2 or image information input from an external device such as a personal computer (not shown) is processed and then converted into an electrical signal which is transmitted to the laser scanner 10 of the image forming unit 1B. The image forming unit 1B then scans the surface of the photoreceptor drum 12 of each process cartridge 11 with laser light corresponding to the image information of yellow, magenta, cyan, and black components emitted from the laser scanner 10. As a result, the surface of the photoreceptor drum 12, which is uniformly charged to a predetermined polarity and potential by the charger 13, is sequentially exposed, and electrostatic latent images of yellow, magenta, cyan, and black are sequentially formed on the photoreceptor drum of each process cartridge 11.

[0013] Next, the developer unit 14 develops and visualizes this electrostatic latent image using yellow, magenta, cyan, and black toners. Then, the primary transfer bias applied to the primary transfer roller 19 sequentially transfers the toner images of each color on each photoreceptor drum onto the intermediate transfer belt 16. As a result, a toner image is formed on the intermediate transfer belt 16.

[0014] On one hand, the sheet S fed out from the sheet feeding device 30 passes through the registration roller pair 40 and is sent to the secondary transfer unit composed of the driving roller 16a and the secondary transfer roller 17. In the secondary transfer unit, the toner image formed in the image forming unit 1B is collectively transferred onto the sheet S. Next, the sheet S onto which the toner image has been transferred in this way is conveyed to the fixing unit 20, and is fixed as a color image on the sheet S by receiving heat and pressure in the fixing unit 20.

[0015] After that, the sheet S on which the image has been fixed is discharged into the discharge space P by the discharge roller pair 25a, 25b, and is stacked on the stacking unit 23 protruding from the bottom surface of the discharge space P. When forming images on both sides of the sheet S, after the image is fixed, the sheet S is conveyed to the re-feed path R by the reversible inversion roller pair 22 provided in the duplex inversion unit 1D, and then is conveyed to the image forming unit 1B again.

[0016] Here, the paper feed cassette 60, which is the sheet storage means, is detachably mounted on the mounting portion 1E shown in FIG. 2 formed at the lower part of the printer main body 1A. As shown in FIG. 2, on the paper feed cassette 60, a back side side regulation plate 61 that regulates one position in the depth direction (width direction) orthogonal to the sheet feeding direction of the sheet S, that is, the position on the downstream side in the depth direction, is provided so as to be movable in the depth direction. Further, on the paper feed cassette 60, a front side side regulation plate 62 that is provided opposite to the back side side regulation plate 61 and regulates the position on the upstream side in the depth direction of the sheet S is provided so as to be movable in the depth direction. The back side side regulation plate 61 and the front side side regulation plate 62 that constitute the pair of side end regulation means 61A move in conjunction with each other so as to regulate the side end positions on the upstream side and the downstream side in the depth direction of the sheet by an interlocking mechanism not shown.

[0017] Further, in the paper feed cassette 60, a rear end regulating plate 63 for regulating the position of the rear end, which is the upstream end of the sheet S in the sheet feeding direction, is provided so as to be movable along the sheet feeding direction. Further, the paper feed cassette 60 is provided with a middle plate (not shown) on which the sheets are stacked, and the position of the sheets stacked on this middle plate is regulated by the back side regulating plate 61, the front side regulating plate 62, and the rear end regulating plate 63.

[0018] On the back side wall 60a of the cassette main body 60A of the paper feed cassette 60, a swing arm 64 having a swing pin 65 at its tip is supported so as to be swingable about a shaft 64a as a fulcrum. Further, on the inner wall surface of the back side of the mounting portion 1E, a drawing-in unit 66, which is a drawing-in means for drawing the paper feed cassette 60 into the mounting portion 1E, is arranged. The drawing-in unit 66 includes a drawing-in unit base 69 and a drawing-in arm 68 provided with a drawing-in hook 67 at its tip and supported so as to be rotatable about a fulcrum 70 on the drawing-in unit base 69.

[0019] A recess 91 for locking the swing pin 65 of the swing arm 64 is formed in the drawing-in hook 67 of the drawing-in arm 68. Further, an arm pin 71 is provided between the drawing-in hook 67 of the drawing-in arm 68 and the fulcrum 70, and the other end of a tension spring 73, one end of which is locked to a base pin 72 provided on the drawing-in unit base 69, is locked to this arm pin 71. Then, the drawing-in arm 68 is urged to rotate about the fulcrum 70 by this tension spring 73.

[0020] When the paper feed cassette 60 is pulled out, while the recess 91 is engaged with the pivot pin 65, the retraction arm 68 rotates counterclockwise from the position shown in Figure 2 around the pivot point 70 in the pulling direction, against the tension spring 73. After this, when the paper feed cassette 60 is pulled out further, the retraction arm 68 rotates to a standby position where the engagement of the pivot pin 65 by the recess 91 is released. Before rotating to the standby position, once the retraction arm 68 has rotated a predetermined amount, a force is applied to the retraction arm 68 by the tension spring 73, causing it to rotate counterclockwise. Due to this force, the retraction arm 68 moves to the standby position and then comes into contact with a stopper (not shown) and stops.

[0021] When in the standby position, the retraction arm 68 is positioned so that when the paper feed cassette 60 is mounted on the printer body 1A, the pivot pin 65 of the pivot arm 64 fits into the recess 91 of the retraction hook 67. Therefore, when the paper feed cassette 60 is inserted into the mounting section 1E, the pivot pin 65 fits into the recess 91 of the retraction hook 67. After this, when the paper feed cassette 60 is pushed further in, the retraction arm 68 is pushed inward via the pivot pin 65 and the retraction hook 67.

[0022] As a result, the retraction arm 68 rotates clockwise around the pivot point 70, resisting the tension spring 73. Once it reaches a predetermined position, the retraction arm 68 rotates clockwise due to the biasing force applied by the tension spring 73. During this clockwise rotation of the retraction arm 68, the recess 91 of the retraction hook 67 engages with the pivot pin 65. Consequently, as the retraction arm 68 rotates beyond the tension spring 73, the paper feed cassette 60 is mounted via the retraction arm 68, receiving a biasing force in the depth direction from the tension spring 73.

[0023] As shown in Figure 2, a positioning unit 74 is provided at one end (right end) of the cassette body 60A perpendicular to the depth direction on the upstream side in the depth direction, which positions the paper feed cassette 60 in the depth direction when the paper feed cassette 60 is installed. When the paper feed cassette 60 is installed, this positioning unit 74 positions the paper feed cassette 60 in the depth direction. After the paper feed cassette 60 is installed, the middle plate, which is provided on the cassette body 60A so as to be rotatable in the vertical direction, is lifted, and the sheet S on the middle plate comes into contact with the pickup roller 75.

[0024] In this embodiment, as shown in Figure 2, a rear side restricting member 80 is provided on the upstream side in the sheet feeding direction of the rear side wall 60a, and a front side restricting member 81 is provided on the upstream side in the sheet feeding direction of the front side wall 60b of the cassette body 60A. The widthwise spacing between the rear side restricting member 80 and the front side restricting member 81, which constitute this pair of upstream end restricting means 80A, is set to the maximum sheet width that can be accommodated in the paper feed cassette 60.

[0025] In this embodiment, since the maximum sheet size is LGL, the distance between the rear side restricting member 80 and the front side restricting member 81 in the width direction is set to the LGL width, and Figure 2 shows the state when an LGL size sheet S1 is stored. These rear side restricting plate 61, front side restricting plate 62, rear end restricting plate 63, rear side restricting member 80, and front side restricting member 81 prevent the sheet S1 from shifting position within the paper feed cassette 60.

[0026] Here, the front side restricting member 81 has a restricting portion (restricting surface) 81a on its side surface, as shown in Figure 3, which restricts the position in the width direction of a predetermined size sheet (LGL size sheet) that has the maximum sheet width among the sheets that can be accommodated in the paper feed cassette 60. The rear side restricting member 80 has the same configuration, so only the front side restricting member 81 will be described below.

[0027] Furthermore, the front side regulating member 81 is provided with a mounting space 81c for selectively attaching an auxiliary side regulating member 82, which is an auxiliary side edge regulating means, from an opening above. Here, the auxiliary side regulating member 82 regulates the widthwise position of small-sized sheets that are smaller than the maximum sheet width that can be accommodated in the paper feed cassette 60, and is provided with a protrusion 82a that abuts against the side edge of the small-sized sheet.

[0028] Furthermore, a slit groove 81b, which is an opening extending vertically, is formed in the center of the regulating portion 81a of the front side regulating member 81 in the sheet feeding direction, causing the protrusion 82a to protrude from the front side regulating member 81 toward the sheet when the auxiliary side regulating member 82 is installed. As a result, as shown in Figure 4(a), when the auxiliary side regulating member 82 is inserted from the opening at the top of the installation space of the front side regulating member 81, the protrusion 82a of the auxiliary side regulating member 82 protrudes from the front side regulating member 81 toward the inside of the cassette body, as shown in Figure 4(b). Note that a vertically extending slide groove (not shown) is formed on the back side of the regulating portion 81a to guide the installation of the auxiliary side regulating member 82 into the installation space 81c from above.

[0029] In this embodiment, when storing small-sized sheets in the paper feed cassette 60, auxiliary side restricting members 82 are attached to the rear side restricting member 80 and the front side restricting member 81. This allows the side edge position of the small-sized sheets stored in the paper feed cassette 60 to be restricted.

[0030] As shown in Figures 3 and 4, an auxiliary member storage section 83 is provided adjacent to the front side wall 60b of the cassette body 60A, in a position that does not interfere with the loading of sheets near the front side regulating member 81. When the auxiliary side regulating member 82 is not used, that is, when loading sheets of the maximum sheet width into the paper feed cassette 60, the auxiliary side regulating member 82 is stored in the auxiliary member storage section 83. This prevents the loss of the auxiliary side regulating member 82.

[0031] In this embodiment, as shown in Figure 5(b) described later, the regulating width provided by the auxiliary side regulating member 82 attached to the rear side regulating member 80 and the front side regulating member 81 is set to an A4 width (210 mm), which is smaller than the LGL width (215.9 mm). When storing a sheet of a smaller size, for example, if you want to set the regulating width to a B5 width (182 mm), prepare an auxiliary side regulating member whose protrusion from the slit groove 81b is set to a B5 width.

[0032] Furthermore, in this embodiment, the positions of the rear side restricting member 80 and the front side restricting member 81 in the sheet feeding direction are set to a position that can restrict the side edges of LTR (215.9 mm) and A4 (210 mm) size sheets. Figure 5(a) shows the state in which an LTR size sheet S2 is stored in the paper feed cassette 60. As a result, when an LTR size sheet S2 is stored, the rear end of the sheet S2 comes into contact with the restricting surfaces of the restricting portion 80a of the rear side restricting member 80 and the restricting portion 81a of the front side restricting member 81, thereby restricting the position of the sheet S2 in the width direction.

[0033] Furthermore, Figure 5(b) shows the state in which an A4-sized sheet S3 is stored in the paper feed cassette 60. When storing an A4-sized sheet S3 in this manner, auxiliary side restricting members 82 are attached to the rear side restricting member 80 and the front side restricting member 81, respectively, as described above. As a result, when an A4-sized sheet S3 is stored, the rear end of the sheet S3 abuts against the convex portion 82a, which is the restricting surface of the auxiliary side restricting member 82, and the position of the sheet S3 in the width direction is restricted. Note that when storing LGL, which is the maximum sheet size in this embodiment, the sheet width of LGL is the same as the sheet width of LTR, so the sheet is stored with the auxiliary side restricting member 82 removed, as shown in Figure 2.

[0034] As explained above, when storing a sheet whose length in the depth direction (width direction) is shorter than a predetermined size sheet, the auxiliary side regulating member 82 is attached to the rear side regulating member 80 and the front side regulating member 81 to regulate the position of the side edge of the sheet. This prevents the sheet from rotating due to impact when inserted into the paper feed cassette 60. As a result, the sheet can be supplied to the image forming unit 1B while suppressing skew and misalignment, and image misalignment relative to the sheet can be suppressed.

[0035] In this embodiment, the auxiliary side restricting member 82 is configured to slide and detach in the sheet loading direction. Therefore, when storing sheets, even if the user touches the auxiliary side restricting member 82 or inserts the paper feed cassette 60 with strong force, the auxiliary side restricting member 82 will not easily detach from the rear side restricting member 80 and the front side restricting member 81. As a result, the position of the sheet in the width direction can be reliably restricted by the auxiliary side restricting member 82. [Explanation of symbols]

[0036] 1...Full-color laser beam printer, 1A...Printer body, 1B...Image forming unit, 1E...Mounting unit, 60...Paper feed cassette, 60A...Cassette body, 60a...Rear side wall of cassette body, 60b...Front side wall of cassette body, 61...Rear side regulating plate, 61A...Side edge regulating means, 62...Front side regulating plate, 63...Rear end regulating plate, 80...Rear side regulating member, 80A...Upstream side regulating means, 81...Front side regulating member, 81a...Regulating part, 81b...Slit groove, 81c...Mounting space, 82...Auxiliary side regulating member, 82a...Protrusion, 83...Auxiliary member housing part, S,S1,S2,S3...Sheet

Claims

1. A sheet storage means for storing a sheet, which is detachably provided on the main body of the device and is attached to the main body of the device by being inserted in the insertion direction, A sheet feeding means that feeds the sheet stored in the sheet storage means attached to the main body of the device in a direction perpendicular to the insertion direction by a roller positioned on the leading edge of the sheet, A side edge regulating means is provided on the sheet storage means so as to be movable in the sheet width direction parallel to the insertion direction, and regulates the position of the side edge of the sheet, A rear end regulating means is provided on the sheet storage means so as to be movable in a direction perpendicular to the insertion direction, and contacts the central part of the rear end of the sheet in the sheet width direction to regulate the position of the rear end of the sheet, The sheet storage means is detachable from the sheet storage means and is attached to a predetermined position when a sheet of a specific size is stored, and includes an auxiliary restricting means that contacts the downstream side end of the sheet of the specific size in the insertion direction, The auxiliary restricting means is detachably attached to the seat storage means independently of the rear end restricting means. The rear end restricting means is movable independently of the auxiliary restricting means. The predetermined position is located on the rear end side of the sheet of the specific size, relative to the side end restricting means. When the sheet storage means, which is attached to the predetermined position, is inserted into the main body of the device in the insertion direction, the auxiliary restricting means abuts against the rear end of the sheet of the specific size, thereby restricting the rear end of the sheet of the specific size from moving downstream in the insertion direction. A sheet feeding device characterized by the following features.

2. The side edge restricting means is positioned such that, in a direction perpendicular to the insertion direction, the distance between the rear end of the sheet of the specified size and the contact point between the side edge of the sheet in the side edge restricting means, specifically the end position on the rear end side of the sheet, is greater than the distance between the front end of the sheet of the specified size and the contact point between the side edge of the sheet in the side edge restricting means, specifically the end position on the front end side of the sheet. The sheet feeding device according to feature 1.

3. The predetermined position in the auxiliary regulating means is set such that, in a direction perpendicular to the insertion direction, the distance between the rear end of the sheet of the specified size and the contact point between the side end of the sheet in the auxiliary regulating means, which is on the rear end side of the sheet, is smaller than the distance between the front end of the sheet of the specified size and the contact point between the side end of the sheet in the side end regulating means, which is on the front end side of the sheet. The sheet feeding device according to feature 1.

4. The auxiliary regulating means is in contact with the rear end of the side edge of the sheet of the specified size, A sheet feeding device according to any one of claims 1 to 3.

5. The length of the contact point between the auxiliary regulating means located at the predetermined position and the side edge of the sheet of the specified size, in a direction perpendicular to the insertion direction, is shorter than the length of the contact point between the side edge regulating means and the side edge of the sheet of the specified size, in a direction perpendicular to the insertion direction. A sheet feeding device according to any one of claims 1 to 4.

6. The sheet of a specific size, whose side edges are restricted by the auxiliary restricting means, is stored in the sheet storage means with the side edges intersecting the insertion direction being the longer sides and the shorter sides aligned with the insertion direction. A sheet feeding device according to any one of claims 1 to 5.

7. The seat storage means and the auxiliary restricting means are configured such that the auxiliary restricting means can be attached to the seat storage means by sliding downward, and can be removed from the seat storage means by sliding upward. A sheet feeding device according to any one of claims 1 to 6.

8. The seat storage means is provided with an opening on the outside in the width direction of the seat relative to the space for storing the seat. The seat storage means and the auxiliary restricting means are configured such that a portion of the auxiliary restricting means is inserted into the opening from above to attach the auxiliary restricting means to the seat storage means, and the auxiliary restricting means is removed from the seat storage means by the auxiliary restricting means, with a portion of it inserted into the opening of the seat storage means, being moved upward. A sheet feeding device according to any one of claims 1 to 7.

9. The sheet storage means is provided with an opening that is located outside the side edge of the sheet of the specified size in the sheet width direction, and above the bottom surface of the sheet storage means on which the sheets are loaded in the sheet loading direction, into which a part of the auxiliary restricting means is inserted from above. The auxiliary restricting means is inserted into the opening from above, thereby determining the position of the auxiliary restricting means relative to the seat storage means in the seat width direction. A sheet feeding device according to any one of claims 1 to 7.

10. The bottom surface of the seat storage means is provided with a hole into which the lower part of the auxiliary regulating means is inserted. The sheet feeding device according to feature 9.

11. The auxiliary restricting means is configured to be detachably attached to multiple positions in the seat storage means. A sheet feeding device according to any one of claims 1 to 10.

12. The system further includes a retraction mechanism that biases the seat storage mechanism toward the insertion direction and pulls the seat storage mechanism into the mounting position. A sheet feeding device according to any one of claims 1 to 11.

13. The auxiliary restricting means is not screwed to the seat storage means. A sheet feeding device according to any one of claims 1 to 12.

14. The seat storage means includes a storage section for accommodating the auxiliary restricting means when the auxiliary restricting means is not in use. The aforementioned housing section is provided upstream of the sheet of the specified size in the insertion direction. A sheet feeding device according to any one of claims 1 to 13.

Images