Image forming device

Abstract

To provide an image formation device capable of preventing a sheet from being rotated due to an impact when sheet storage means is inserted.SOLUTION: A side end position in a width direction of a sheet of a predetermined size stored in a sheet feed cassette 60, is regulated by a depth-side side regulating member 80 and a front-side side regulating member 81 provided on an upstream side of a depth-side side regulating plate 61 and a front-side side regulating plate 62 in a sheet feeding direction. Then, when a sheet of a small size S3 having a shorter width in the width direction than the sheet of the predetermined size is stored in the sheet feed cassette 60, an auxiliary side regulating member 82 is attached to the depth-side regulating member 80 and the front-side regulating member 81, thereby regulating the side end position in the width direction of sheet of the small size S3.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, Nisi R Place of This relates to a configuration that regulates the placement of [Background technology]

[0002] In recent years, in image forming apparatuses such as copying machines, printers, and facsimiles, there have been widespread devices that feed sheets stored in a sheet storage means to an image forming section to form an image. As such sheet storage means, there is one that is provided with a plate-shaped sheet stacking means for stacking sheets, which can be raised and lowered.

[0003] When replenishing sheets, the sheet stacking means is lowered, and when feeding sheets, the sheet stacking means is raised to move the top surface of the stacked sheets to a position where they can be fed by the pickup roller above. Also, the sheet storage means is provided in the device body so as to be removable, and when storing sheets, the sheet storage means is pulled out and then the sheets are set on the sheet stacking means from above.

[0004] The sheet storage means is provided with a rear end regulating means movable along the sheet feeding direction for regulating the position of the upstream end (hereinafter referred to as the rear end) of the sheets loaded on the sheet stacking means in the sheet feeding direction so that sheets of different sizes can be stored. The sheet storage means is also provided with a side end regulating means movable in the width direction for regulating the side end position of the sheets in a direction perpendicular to the sheet feeding direction (hereinafter referred to as the width direction). The side end regulating means regulates the side end of the sheet, and the rear end regulating means regulates the rear end of the sheet, thereby regulating the position of the sheet to a predetermined position (see Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 3359174 Summary of the Invention [Problem to be solved by the invention]

[0008] by the way , salary Paper Cassette of When inserting, the paper feed cassette To When an impact is applied, the seat Is Fall over .child As a result, the sheet is Inside The image on the sheet may be misaligned by the amount of the misalignment, or the sheet may be skewed, resulting in an image being formed on the sheet at an angle.

[0009] Therefore, the present invention has been made in consideration of the above-mentioned current situation, and has an object to provide an image forming apparatus that can prevent a sheet from rotating due to an impact when being inserted into a sheet storage means. [Means for solving the problem]

[0010] One aspect of the present invention includes a sheet storage means for storing sheets, which is detachably attached to an image forming apparatus main body and is attached to the image forming apparatus main body by being inserted in an insertion direction; a sheet feeding means for feeding a sheet stored in the sheet storage means attached to the image forming apparatus main body in a direction perpendicular to the insertion direction by a roller arranged on a leading end side of the sheet; an image forming unit for forming an image on the sheet fed by the sheet feeding means; a side end regulating means provided in the sheet storage means to be movable in a sheet width direction parallel to the insertion direction and contacting a side end of the sheet stored in the sheet storage means along a direction perpendicular to the insertion direction to regulate a position of the sheet; a rear end regulating means provided on the sheet storage means so as to be movable in the insertion direction, the rear end regulating means contacting a center portion in the insertion direction of a rear end of a sheet stored in the sheet storage means to regulate a position of the sheet; and an auxiliary regulating means detachably attached to the sheet storage means, the auxiliary regulating means being attached at a predetermined position when a sheet of a specific size is stored, the auxiliary regulating means being disposed closer to the rear end of the sheet of the specific size than the side end regulating means in a direction perpendicular to the insertion direction, the auxiliary regulating means contacting a downstream side end in the insertion direction of the sheet of the specific size stored in the sheet storage means to regulate rotation of the sheet of the specific size when the sheet storage means is attached to the image forming apparatus main body, the auxiliary regulating means is detachable from the sheet storing means independently of the trailing end regulating means, and the trailing end regulating means is movable independently of the auxiliary regulating means; This image forming apparatus is characterized in that when a sheet of the specific size is stored in the sheet storage means, the auxiliary regulating means, the side end regulating means and the rear end regulating means at the predetermined position regulate the sheet of the specific size, and the side end regulating means is positioned at a position where, in a direction perpendicular to the insertion direction, the distance between the rear end of the sheet of the specific size and the point of contact between the side end of the sheet on the side end regulating means is greater than the distance between the leading end of the sheet of the specific size and the point of contact between the side end of the sheet on the side end regulating means, and the predetermined position of the auxiliary regulating means is set at a position where, in a direction perpendicular to the insertion direction, the distance between the rear end of the sheet of the specific size and the point of contact between the side end of the sheet on the auxiliary regulating means is smaller than the distance between the leading end of the sheet of the specific size and the point of contact between the side end of the sheet on the side end regulating means. Effect of the Invention

[0011] The present invention According to Sheet of Rotation can be prevented. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a schematic configuration of a full-color laser beam printer as an example of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] 2A and 2B are diagrams illustrating the configuration of a mounting unit of the full-color laser beam printer and a paper feed cassette that is detachably mounted in the mounting unit; [Diagram 3] 5A and 5B are diagrams illustrating a configuration of a front side regulating member provided in the paper feed cassette. [Figure 4] 10A to 10C are diagrams illustrating an operation of attaching an auxiliary side regulating member to the front side regulating member. [Diagram 5] 6A and 6B are diagrams illustrating a state in which sheets of different sizes are stored in the paper feed cassette. [Figure 6] FIG. 1 illustrates a configuration of a conventional paper feed cassette. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An example of the sheet feeding device of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing 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. In FIG. 1, 1 is a full-color laser beam printer (hereinafter referred to as printer), 1A is a printer main body which is the main body of the image forming apparatus, 1B is an image forming section which forms an image on a sheet, and 20 is a fixing section. 2 is an image reading device which is an upper device installed approximately horizontally above the printer main body 1A, and a discharge space P is formed between this image reading device 2 and the printer main body 1A. In addition, 30 is a sheet feeding device provided at the bottom of the printer main body 1A, and 15 is a toner cartridge.

[0014] 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 subjected to image processing, converted into an electric signal, and transmitted to a laser scanner 10 of the image forming unit 1B. Then, in the image forming unit 1B, the surface of the photosensitive drum 12 of each process cartridge 11 is scanned with laser light corresponding to image information of yellow, magenta, cyan, and black component colors emitted from the laser scanner 10. As a result, the surface of the photosensitive drum 12, the surface of which is uniformly charged to a predetermined polarity and potential by the charger 13, is sequentially exposed to light, and electrostatic latent images of yellow, magenta, cyan, and black are sequentially formed on the photosensitive drum of each process cartridge 11, respectively.

[0015] Thereafter, the electrostatic latent image is developed and visualized by the developing device 14 using toner of each color, yellow, magenta, cyan, and black. Then, the toner images of each color on each photoconductor drum are transferred in order, superimposed on the intermediate transfer belt 16, by a primary transfer bias applied to the primary transfer roller 19. As a result, a toner image is formed on the intermediate transfer belt 16.

[0016] Meanwhile, the sheet S sent out from the sheet feeding device 30 passes through a pair of registration rollers 40 and is sent to a secondary transfer section constituted by a drive roller 16a and a secondary transfer roller 17. In the secondary transfer section, the toner images formed in the image forming section 1B are transferred all at once onto the sheet S. Next, the sheet S onto which the toner images have been transferred in this manner is conveyed to the fixing section 20, where the toner images are fixed onto the sheet S as a color image by being subjected to heat and pressure.

[0017] Thereafter, the sheet S on which the image has been fixed is discharged to the discharge space P by the pair of discharge rollers 25a, 25b, and is stacked on the stacking section 23 protruding from the bottom surface of the discharge space P. When images are formed on both sides of the sheet S, after the images are fixed, the sheet S is transported to a re-conveying path R by a pair of reversible rollers 22 provided in the double-sided reversing section 1D, which are capable of forward and reverse rotation, and is then transported again to the image forming section 1B.

[0018] Here, the sheet cassette 60, which is a sheet storage means, is detachably mounted in a mounting portion 1E shown in FIG. 2 formed at the bottom of the printer main body 1A. As shown in FIG. 2, the sheet cassette 60 is provided with a rear side regulating plate 61 that regulates one of the depth directions (width directions) perpendicular to the sheet feeding direction of the sheet S, i.e., the downstream side position in the depth direction, so as to be movable in the depth direction. The sheet cassette 60 is also provided with a front side regulating plate 62 that is provided opposite the rear side regulating plate 61 and regulates the upstream side position in the depth direction of the sheet S, so as to be movable in the depth direction. The rear side regulating plate 61 and the front side regulating plate 62 that constitute a pair of side end regulating means 61A move in conjunction with each other to regulate the upstream side and downstream side side end positions in the depth direction of the sheet by an interlocking mechanism (not shown).

[0019] The sheet feed cassette 60 is provided with a rear end regulating plate 63 that is movable along the sheet feed direction and regulates the position of the rear end, which is the upstream end in the sheet feed direction, of the sheet S. The sheet feed cassette 60 is further provided with a middle plate (not shown) on which sheets are stacked. The positions of the sheets stacked on the middle plate are regulated by the rear side regulating plate 61, the front side regulating plate 62 and the rear end regulating plate 63.

[0020] A swing arm 64 having a swing pin 65 at its tip is supported on a shaft 64a as a fulcrum on a rear side wall 60a of the cassette body 60A of the paper feed cassette 60 so as to be swingable about a shaft 64a. A retraction unit 66, which is a retraction means for retracting the paper feed cassette 60 into the mounting section 1E, is disposed on the rear inner wall surface of the mounting section 1E. The retraction unit 66 includes a retraction unit base 69 and a retraction arm 68 having a retraction hook 67 at its tip and supported on the retraction unit base 69 so as to be rotatable about a fulcrum 70.

[0021] A recess 91 for engaging the swing pin 65 of the swing arm 64 is formed in the retraction hook 67 of the retraction arm 68. An arm pin 71 is provided between the retraction hook 67 of the retraction arm 68 and the fulcrum 70, and one end of a tension spring 73 is engaged with a base pin 72 provided on the retraction unit base 69, and the other end of the tension spring 73 is engaged with the arm pin 71. The retraction arm 68 is biased by the tension spring 73 to rotate around the fulcrum 70.

[0022] When the paper feed cassette 60 is pulled out, while the recess 91 is locking the swing pin 65, the retraction arm 68 rotates counterclockwise from the position shown in FIG. 2 around the fulcrum 70 in the pulling direction against the tension spring 73. When the paper feed cassette 60 is subsequently pulled out further, the retraction arm 68 rotates to a standby position where the lock of the swing pin 65 by the recess 91 is released. When the retraction arm 68 rotates a predetermined amount before rotating to the standby position, a force to rotate counterclockwise is applied to the retraction arm 68 by the tension spring 73. This force causes the retraction arm 68 to move to the standby position and then come into contact with a stopper (not shown) and stop.

[0023] When the retracting arm 68 is in the standby position, the retracting arm 68 is in a position where the swing pin 65 of the swing arm 64 enters the recess 91 of the retracting hook 67 when the paper feed cassette 60 is mounted in the printer main body 1A. Therefore, when the paper feed cassette 60 is inserted into the mounting section 1E, the swing pin 65 enters the recess 91 of the retracting hook 67. If the paper feed cassette 60 is then pushed further in, the retracting arm 68 is pressed toward the rear via the swing pin 65 and the retracting hook 67.

[0024] As a result, the retractable arm 68 rotates clockwise around the fulcrum 70 against the tension spring 73, and thereafter, when it rotates to a predetermined position, the retractable arm 68 rotates clockwise due to the biasing force of the tension spring 73. Then, in the process of the retractable arm 68 rotating clockwise in this manner, the recess 91 of the retractable hook 67 engages with the swing pin 65. As a result, when the retractable arm 68 rotates due to the tension spring 73, the paper feed cassette 60 is attached while receiving a biasing force in the depth direction from the tension spring 73 via the retractable arm 68.

[0025] 2, a positioning portion 74 is provided at one end (right end) of the cassette body 60A that is perpendicular to the depth direction and upstream in the depth direction, for positioning the sheet feed cassette 60 in the depth direction when the sheet feed cassette 60 is attached. When the sheet feed cassette 60 is attached, the positioning portion 74 positions the sheet feed cassette 60 in the depth direction. After the sheet feed cassette 60 is attached, a middle plate that is provided on the cassette body 60A so as to be rotatable in the vertical direction is lifted, and the sheets S on the middle plate come into contact with the pickup roller 75.

[0026] 2, in this embodiment, a rear side regulating member 80 is provided on the upstream side of the rear side wall 60a in the sheet feeding direction, and a front side regulating member 81 is provided on the upstream side of the front side wall 60b of the cassette body 60A in the sheet feeding direction. The widthwise distance between the rear side regulating member 80 and the front side regulating member 81 constituting the pair of upstream end regulating means 80A is set to the maximum sheet width that can be accommodated in the sheet feed cassette 60.

[0027] In this embodiment, since the maximum sheet size is LGL, the widthwise distance between the rear side regulating member 80 and the front side regulating member 81 is set to the LGL width, and Fig. 2 shows a state when a sheet S1 of LGL size is stored. The rear side regulating plate 61, the front side regulating plate 62, the trailing end regulating plate 63, the rear side regulating member 80, and the front side regulating member 81 prevent the sheet S1 from being displaced in the paper feed cassette 60.

[0028] 3, the front side regulating member 81 has a regulating portion (regulating surface) 81a on its side that regulates the widthwise position of a sheet of a predetermined size (a sheet of LGL size) that has the maximum sheet width among sheets that can be stored in the paper feed cassette 60. Note that the rear side regulating member 80 has the same configuration, so only the front side regulating member 81 will be described below.

[0029] Further, the front side regulating member 81 is provided with an attachment space 81c for selectively attaching an auxiliary side regulating member 82, which is an auxiliary side end regulating means, from an upper opening. 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 has a protrusion 82a that comes into contact with the side end of the small-sized sheet.

[0030] In addition, a slit groove 81b, which is an opening extending in the vertical direction and causes the protrusion 82a to protrude from the front side regulating member 81 to the sheet side when the auxiliary side regulating member 82 is attached, is formed in the center of the regulating portion 81a of the front side regulating member 81 in the sheet feeding direction. As a result, when the auxiliary side regulating member 82 is inserted from the opening at the top of the attachment space of the front side regulating member 81 as shown in Fig. 4(a), the protrusion 82a of the auxiliary side regulating member 82 protrudes from the front side regulating member 81 to the inside of the cassette body as shown in Fig. 4(b). Note that a slide groove (not shown) extending in the vertical direction is formed on the back side of the regulating portion 81a to guide the attachment of the auxiliary side regulating member 82 to the attachment space 81c from above.

[0031] In this embodiment, when small-sized sheets are stored in the paper feed cassette 60, auxiliary side regulating members 82 are attached to the rear side regulating member 80 and the front side regulating member 81. This makes it possible to regulate the side edge positions of small-sized sheets stored in the paper feed cassette 60.

[0032] 3 and 4, an auxiliary member accommodating portion 83 is provided adjacent to the front side wall 60b of the cassette body 60A at a position that does not interfere with stacking of sheets near the front side regulating member 81. When the auxiliary side regulating member 82 is not used, that is, when sheets of the maximum sheet width are stored in the paper feed cassette 60, the auxiliary side regulating member 82 is stored in the auxiliary member accommodating portion 83. This makes it possible to prevent the auxiliary side regulating member 82 from being lost.

[0033] In this embodiment, the regulating width by the auxiliary side regulating members 82 attached to the rear side regulating member 80 and the front side regulating member 81 is set to A4 width (210 mm) which is smaller than the LGL width (215.9 mm) as shown in Fig. 5(b) described later. When storing sheets of a smaller size, for example when the regulating width is to be set to B5 width (182 mm), an auxiliary side regulating member is prepared whose protrusion amount from the slit groove 81b is set to B5 width.

[0034] In this embodiment, the positions of the rear side regulating member 80 and the front side regulating member 81 in the sheet feeding direction are set to positions where the side edges of LTR (215.9 mm) and A4 (210 mm) size sheets can be regulated. Note that Fig. 5(a) shows a state where 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 abuts against the regulating surfaces of the regulating portion 80a of the rear side regulating member 80 and the regulating portion 81a of the front side regulating member 81, and the position of the sheet S2 in the width direction is regulated.

[0035] 5B shows a state in which A4-sized sheets S3 are stored in the sheet feed cassette 60. When A4-sized sheets S3 are stored in this manner, the auxiliary side regulating members 82 are attached to the rear side regulating member 80 and the front side regulating member 81, as described above. As a result, when A4-sized sheets S3 are stored, the rear end of the sheets S3 abuts against the convex portion 82a, which serves as the regulating surface of the auxiliary side regulating member 82, and the widthwise position of the sheets S3 is regulated. 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 sheets are stored with the auxiliary side regulating member 82 removed, as shown in FIG. 2.

[0036] As described above, when storing sheets whose length in the depth direction (width direction) is shorter than that of sheets of a predetermined size, the auxiliary side regulating members 82 are attached to the rear side regulating members 80 and the front side regulating members 81 to regulate the side edge positions of the sheets. This makes it possible to prevent the sheets from rotating due to the impact when the sheet feed cassette 60 is inserted. As a result, the sheets can be supplied to the image forming unit 1B in a state in which skewing and positional deviation are suppressed, and image deviation on the sheets can be suppressed.

[0037] In this embodiment, the auxiliary side regulating member 82 is configured to slide in the sheet stacking direction and be detached. Therefore, even if the user touches the auxiliary side regulating member 82 or inserts the paper feed cassette 60 with great force when storing sheets, the auxiliary side regulating member 82 will not easily come off the rear side regulating member 80 and the front side regulating member 81. As a result, the auxiliary side regulating member 82 can reliably regulate the widthwise position of the sheet. [Explanation of symbols]

[0038] 1...full-color laser beam printer, 1A...printer body, 1B...image forming section, 1E...mounting section, 60...paper feed cassette, 60A...cassette body, 60a...back side wall of cassette body, 60b...front side wall of cassette body, 61...back side regulation plate, 61A...side end regulation means, 62...front side regulation plate, 63...rear end regulation plate, 80...back side regulation member, 80A...upstream end regulation means, 81...front side regulation member, 81a...regulation section, 81b...slit groove, 81c...mounting space, 82...auxiliary side regulation member, 82a...projection, 83...auxiliary member storage section, S, S1, S2, S3...sheet

Claims

1. a sheet storage unit that stores sheets, is detachably provided on the image forming apparatus body, and is attached to the image forming apparatus body by being inserted in an insertion direction; a sheet feeding means for feeding the sheet stored in the sheet storage means attached to the image forming apparatus body in a direction perpendicular to the insertion direction by a roller disposed on the leading end side of the sheet; an image forming section for forming an image on the sheet fed by the sheet feeding means; a side end regulating means provided in the sheet storage means so as to be movable in a sheet width direction parallel to the insertion direction, the side end regulating means contacting a side end of the sheet stored in the sheet storage means along a direction perpendicular to the insertion direction to regulate a position of the sheet; a rear end regulating means provided on the sheet storage means so as to be movable in a direction perpendicular to the insertion direction, the rear end regulating means contacting a center portion of a rear end of a sheet stored in the sheet storage means in the insertion direction to regulate a position of the sheet; an auxiliary regulating means detachably attached to the sheet storage means, the auxiliary regulating means being attached at a predetermined position when a sheet of a specific size is stored, the auxiliary regulating means being disposed toward the rear end of the sheet of the specific size relative to the side end regulating means in a direction perpendicular to the insertion direction, and contacting a downstream side end in the insertion direction of the sheet of the specific size stored in the sheet storage means to regulate rotation of the sheet of the specific size when the sheet storage means is attached to the image forming apparatus main body; the auxiliary regulating means is detachable from the sheet storing means independently of the trailing end regulating means, the trailing edge regulating means is movable independently of the auxiliary regulating means, When a sheet of the specific size is stored in the sheet storage means, the auxiliary regulating means, the side end regulating means and the rear end regulating means at the predetermined positions regulate the sheet of the specific size, the side edge regulating means is disposed at a position where, in a direction perpendicular to the insertion direction, a distance between a rear end of a sheet of the specific size and a contact point of the side edge regulating means with the sheet is greater than a distance between a front end of a sheet of the specific size and a contact point of the side edge regulating means with the sheet, An image forming apparatus characterized in that the specified position of the auxiliary regulating means is set at a position in a direction perpendicular to the insertion direction such that the distance between the rear end of a sheet of the specific size and the contact point between the side end of the sheet on the auxiliary regulating means is smaller than the distance between the leading end of a sheet of the specific size and the contact point between the side end of the sheet on the side end regulating means.

2. An image forming apparatus as described in claim 1, characterized in that the length of the contact point of the auxiliary regulating means positioned at the specified position with the side end of the specific size sheet in a direction perpendicular to the insertion direction is shorter than the length of the contact point of the side end regulating means with the side end of the specific size sheet in a direction perpendicular to the insertion direction.

3. An image forming apparatus as described in claim 1 or 2, characterized in that the sheet of the specific size whose side edge is regulated by the auxiliary regulating means is stored in the sheet storage means with the side edge that intersects the insertion direction being the long side and the short side aligned with the insertion direction.

4. 4. An image forming apparatus as claimed in claim 1, wherein the sheet storage means and the auxiliary regulating means are configured so that the auxiliary regulating means can be attached to the sheet storage means by sliding downward and the auxiliary regulating means can be removed from the sheet storage means by sliding upward.

5. The sheet storage means is provided with an opening on the outer side in the sheet width direction with respect to a space for storing the sheets, An image forming apparatus as described in any one of claims 1 to 4, characterized in that the auxiliary regulating means is attached to the sheet storage means by inserting a portion of the auxiliary regulating means into the opening from above, and the auxiliary regulating means, the portion of which is inserted into the opening of the sheet storage means, is moved upward to remove the auxiliary regulating means from the sheet storage means.

6. The sheet storage means includes: a hole disposed on a bottom surface of the sheet storage means and into which a lower portion of the auxiliary regulating means is inserted; An image forming apparatus as described in any one of claims 1 to 4, characterized in that an opening is provided that is positioned outside the hole and the space for storing the sheet in the sheet width direction and above the hole in the sheet stacking direction, and into which a portion of the auxiliary regulating means is inserted from above.

7. 7. The image forming apparatus according to claim 1, wherein the auxiliary regulating means is configured to be detachably attached to a plurality of positions in the sheet storing means.

8. 6. The image forming apparatus according to claim 1, further comprising a retracting unit that urges the sheet storage unit in the insertion direction to retract the sheet storage unit into a mounting position.

Images