JP2007308210A - Paper feeding cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding cassette capable of being commonly used and attached so as to come in and out of both image forming device main body and paper feeding device main body extendable by piling up at a plurality of steps, and preventing unnecessary parts from being arranged as they are. <P>SOLUTION: This paper feeding cassette C2 is composed of a cassette main body 1 and a unit 2 capable of being freely attached or detached to/from the cassette main body 1. Conveyance rollers 3a, 3b coming into pressure-contact with a conveyance roller 43 attached to a paper feeding device main body FB side when the paper feeding cassette C2 is mounted on the paper feeding device main body FB are attached to the unit 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet feeding cassette, and more particularly to an image forming apparatus main body and a sheet feeding cassette that is detachably attached to a sheet feeding apparatus that can be expanded by being stacked in a plurality of stages.

  2. Description of the Related Art In image forming apparatuses such as facsimiles, printers, and copiers, the apparatus body is usually provided with a paper feed cassette that allows a predetermined number of sheets of a predetermined size to be loaded. In addition, when a plurality of sizes of paper are used, a plurality of paper feeders on which the paper of each size is placed are stacked under the image forming apparatus main body.

  FIG. 6 shows a conventional image forming apparatus in which one sheet feeding device is stacked below the main body of the image forming apparatus. As shown in the figure, when the paper P is supplied from the paper feed cassette C1 ′ provided in the image forming apparatus main body MB, the paper P placed on the paper feed cassette C1 ′ by the pickup roller 40 is removed. The paper P is pulled out in the direction of the transport path, and the paper P is supplied to the transport path one by one by the feed roller 42 and the separating roller 41. Then, the sheet P is sent to a registration roller (not shown) through a conveyance roller pair 81 provided in the middle of the conveyance path. Since the distance from the nip portion of the feed roller 42 and the separation roller 41 to the nip portion of the conveyance roller pair 81 is shorter than the length of the minimum size paper that can be placed on the paper feed cassette C1 ′, the feed roller 42 and the separation roller In the state where the sheet is sandwiched by 41, the leading end of the sheet P is sandwiched by the transport roller pair 81. As a result, the paper P is smoothly conveyed.

  On the other hand, when the paper P is supplied from the paper feed cassette C2 ′ provided in the paper feeder main body FB, the paper is pulled out in the direction of the transport path by the pickup roller 40, and the paper is fed one by one by the feed roller 42 and the separating roller 41. The point that P is supplied to the conveyance path is the same as that of the sheet feeding cassette C1 ′ of the image forming apparatus main body MB. However, unlike the paper feed cassette C1 ′ of the image forming apparatus main body MB, in the paper feed cassette C2 ′ of the paper feed apparatus main body FB, from the nip portion of the feed roller 42 and the separating roller 41 to the nip portion of the conveying roller pair 81. Therefore, depending on the size of the paper placed in the paper feed cassette C2 ′, even if the rear edge of the paper passes through the nip portion between the feed roller 42 and the separation roller 41, the front edge of the paper is There is a case where it is not yet clamped by the transport roller pair 81. In this case, the sheet cannot be conveyed. Therefore, as shown in the drawing, the sheet feeding cassette C2 ′ provided in the sheet feeding apparatus main body FB has a conveying roller 43 and a conveying roller that are in pressure contact with the feeding roller 42 and the separating roller 41 on the downstream side in the conveying direction. The roller 3 is provided, and the paper is nipped and conveyed by the conveyance roller 43 and the conveyance roller 3 until the leading end is nipped by the conveyance roller pair 81 even for a small size sheet.

As described above, in the conventional paper feed cassette, there are different forms depending on what is attached to the image forming apparatus main body MB and what is attached to the paper feed apparatus main body FB.
JP 2002-293443 A

  However, in recent years, sharing of parts has been promoted in various products from the viewpoint of reducing production costs and simplifying parts management, and sharing of parts has also been promoted in image forming apparatuses. Regarding the paper feed cassette, it is conceivable to use the paper feed cassette C2 'mounted on the paper feed apparatus main body FB as the paper feed cassette mounted on the image forming apparatus main body MB.

  However, if the paper feed cassette C2 ′ attached to the paper feed apparatus main body FB is also used as a paper feed cassette to be attached to the image forming apparatus main body MB, it is not necessary for the paper feed cassette of the image forming apparatus main body MB. The roller 3 will be arranged as it is.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to share a sheet feeding cassette mounted on the image forming apparatus main body and the paper feeding apparatus main body, and to provide unnecessary parts. It is to prevent it from being placed as it is.

  According to the present invention, the image forming apparatus main body and the paper feeding apparatus main body that can be expanded by stacking in a plurality of stages are attached to the paper feeding apparatus main body so as to be freely accessible. In addition, a paper feed cassette is provided in which a transport roller that comes into pressure contact with the transport roller is detachably provided.

  Here, from the viewpoint of facilitating attachment / detachment of the conveyance roller, it is preferable that the unit to which the conveyance roller is attached is detachable from the paper feed cassette.

  Further, according to the present invention, there is provided a paper feeding device comprising the paper feeding cassette described above.

  The sheet feeding cassette of the present invention can be mounted on either the image forming apparatus body or the sheet feeding apparatus body. In addition, since the conveyance roller that presses the conveyance roller attached to the sheet feeding device main body side is detachably provided, if the conveyance roller is removed when the image forming device main body is mounted, unnecessary parts are arranged as they are. Disappears.

  Further, if the transport roller is attached to the unit and the unit is detachable from the paper feed cassette, the transport roller can be easily attached and detached.

  Hereinafter, a paper feed cassette and a paper feed device according to the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a schematic configuration diagram of a full-color image forming apparatus in which an embodiment of the present invention is adopted. In the image forming apparatus of FIG. 1, an image forming unit 5 is provided substantially at the center. The image forming unit 5 includes a photoconductor drum 6 using an a-Si photoconductor and a charging device 51, an exposure device 52, a developing device 53, a transfer device 7, and a cleaning device disposed around the photoconductor drum 6. 54. A fixing device 9 is disposed downstream of the photosensitive drum 6 in the sheet conveyance direction. A paper feed cassette C1 is attached to the lower part of the image forming apparatus M so as to be able to enter and leave the image forming apparatus main body MB. A sheet feeding device F is attached to the lower part of the image forming apparatus M. The sheet feeding devices F can be stacked in a plurality of stages as necessary. The paper feed cassettes C1 and C2 and the paper feed device F will be described later.

  The photosensitive drum 6 has an electrostatic latent image formed on the surface. The charging device 51 is installed above the photosensitive drum 6 and is a device for uniformly charging the photosensitive drum 6. The exposure device 52 is a device for forming an electrostatic latent image on the photosensitive drum 6 based on a document image read from an image data input unit (not shown).

  The developing device 53 is a device that forms a toner image by supplying toner to the surface of the photosensitive drum 6 on which the electrostatic latent image is formed. Here, the developing device 53 includes a rotary rack 531 and a plurality of developing devices 5Y, 5M, 5C, and 5B. The rotary rack 531 is configured to perform development by sequentially moving a plurality of developing units 5Y, 5M, 5C, and 5B to a developing position facing the photosensitive drum 6 while rotating around a rotating shaft 532 by a rotating means (not shown). It is. Among the plurality of developing devices, the yellow developing device 5Y, the magenta developing device 5M, the cyan developing device 5C, and the black developing device 5B are held side by side in the circumferential direction of the rotary rack 531 in the order of 5Y, 5M, 5C, and 5B. The developing units are arranged at intervals of about 90 degrees in the circumferential direction.

  The transfer device 7 is a device for transferring the toner image on the photosensitive drum 6 to a sheet, and includes an intermediate transfer belt 71, primary transfer rollers 72 and 73, a driving roller 75, a secondary transfer counter roller 74, and a secondary transfer. A roller 76 is provided. The intermediate transfer belt 71 is wound endlessly around the primary transfer rollers 72 and 73, the drive roller 75, and the secondary transfer counter roller 74, and is driven by the drive roller 75, and the toner image formed on the photosensitive drum 6. Plays the role of a transcript that is transferred and temporarily held. The secondary transfer roller 76 is disposed on the outer peripheral surface of the intermediate transfer belt 71 at a position facing the secondary transfer counter roller 74 and plays a role of secondary transfer of the toner image onto the sheet.

  The cleaning device 54 is a device for cleaning deposits such as residual developer remaining on the photosensitive drum 6, and the image forming apparatus is provided with a cleaning blade. The fixing device 9 is a device for heating and pressurizing the transferred toner image to melt and fix it on a sheet.

  In the image forming apparatus M having such a configuration, at the time of image formation, after the photosensitive drum 6 is charged by the charging unit 51, the rotary rack 531 rotates around the rotation shaft 532, and the first color is yellow. Is provided at a position facing the photosensitive drum 6. The exposure unit 52 performs exposure corresponding to yellow, and an electrostatic latent image corresponding to yellow is formed on the surface of the photosensitive drum 6. This electrostatic latent image is converted into a toner image by the developing device 5Y. The toner image formed on the surface of the photosensitive drum 6 is transferred onto the transfer belt 71 by a transfer bias applied to the primary transfer rollers 72 and 73. When the formation of the yellow toner image on the transfer belt 71 is completed in this way, the rotary rack 531 rotates about the rotation shaft 532, and then the developing device 5M corresponding to magenta is disposed at the development position. Such an operation is also performed for other colors, magenta, cyan, and black, and a full-color toner image is formed on the transfer belt 71.

  In the process in which the toner images of the respective colors are primarily transferred to the intermediate transfer belt 71, the secondary transfer roller 76 is held away from the transfer belt 71. On the other hand, when a full-color toner image is formed on the transfer belt 71, the secondary transfer roller 76 is in contact with the transfer belt 71. Then, by applying a secondary transfer via to the secondary transfer roller 76, the full-color toner image on the transfer belt 71 is transferred to the paper P that has been conveyed to the transfer position in time by the registration roller pair 82. To do. The sheet P on which the toner image is transferred is conveyed to the fixing unit 9. The fixing unit 9 applies heat and pressure to the toner image on the paper, and the toner image is fixed on the paper P. Thereafter, the paper P is discharged onto the paper discharge tray 85 through the conveyance roller pair 83 and the paper discharge roller pair 84.

  The developer remaining on the photosensitive drum 6 is cleaned by the cleaning blade 54 and discarded in a waste toner container (not shown). The toner remaining on the transfer belt 71 is cleaned by bringing a cleaning device (not shown) of the transfer belt 71 into contact with the transfer belt 71 after the secondary transfer, and is discarded in a waste toner container (not shown). The cleaning device for the transfer belt 71 is separated from the transfer belt 71 after cleaning the entire circumference of the transfer belt 71.

  FIG. 2 shows a perspective view of the paper feed cassette C2 used in the image forming apparatus of FIG. 1, and FIG. 3 shows a perspective view of the cassette main body 1 with the unit 2 removed. The sheet feeding cassette C2 in this figure is used in common for both the image forming apparatus body MB and the sheet feeding apparatus body FB. As shown in FIG. 3, the paper feed cassette C <b> 2 includes a cassette body 1 and a unit 2 that can be attached to and detached from the cassette body 1. An elevating plate 11 is attached to the inner bottom surface of the cassette body 1 so as to be swingable about the shafts 14a and 14b. The elevating plate 11 is urged upward by a spring (not shown) attached to the back side. As a result, the sheet placed on the elevating plate 11 is also urged upward and comes into contact with the pickup roller 40 (shown in FIG. 4) attached to the sheet feeder main body FB side. Further, side cursors 12a and 12b for regulating the positions of the left and right sides and the rear side of the sheet and a back cursor 13 are slidably attached to the inner bottom surface of the cassette body 1.

  A separation roller 41 is rotatably attached to the side wall of the cassette body 1 on the downstream side in the paper conveyance direction. The separation roller 41 comes into pressure contact with a feed roller 42 (shown in FIG. 4) attached to the sheet feeding apparatus body FB side when the sheet feeding cassette C is mounted on the sheet feeding apparatus body FB. Further, an attachment surface 10 for attaching the unit 2 is formed on the upper surface of the side wall of the cassette body 1, and four locking holes 16a, 16b, 16c, 16d are symmetrically formed about the center in the width direction. Two positioning holes 15a and 15b are formed.

  On the other hand, the unit 2 has a long and thin rectangular parallelepiped shape, and two conveying rollers 3a and 3b are attached to one side surface so as to be rotatable at a separated position. Further, four claw portions 22a, 22b, 22c, and 22d and two rod-shaped portions 21a and 21b that are slightly longer than these claw portions are formed on the bottom surface of the unit 2.

  When the unit 2 is attached to the cassette body 1, the rod-like portions 21 a and 21 b of the unit 2 are first inserted into the positioning holes 15 a and 15 b formed in the attachment surface 10 of the cassette body 1. As a result, the unit 2 is positioned with respect to the cassette body 1. Then, the unit 2 is moved closer to the cassette body 1. When the unit 2 is just in contact with the mounting surface 10 of the cassette body 1, the claw portions 22a, 22b, 22c and 22d of the unit 2 are engaged with the locking holes 16a, 16b, 16c and 16d of the mounting surface 10, respectively. 2 is fixed to the cassette body 1. On the other hand, when removing the unit 2 from the cassette body 1, the claws 22a, 22b, 22c, 22d and the locking holes 16a, 16b, 16c are elastically deformed by applying force to the claws 22a, 22b, 22c, 22d. , 16d is released and the unit 2 is separated from the cassette body 1. In this way, the unit 2 is detachably attached to the cassette body 1. Of course, the attachment / detachment mechanism of the unit 2 is not limited to such a mechanism, and a conventionally known mechanism can be adopted.

  FIG. 4 shows a schematic diagram when the paper feed cassette shown in FIGS. 2 and 3 is mounted on the image forming apparatus main body MB and the paper feed apparatus main body FB. The difference between the paper feed cassette C1 and the paper feed cassette C2 is that the unit 2 is attached to the paper feed cassette C2, and the unit 2 is attached to the paper feed cassette C1. Since other configurations are common, the sheet cassette C2 will be described as a representative. A lift plate 11 is attached to the bottom surface of the sheet cassette C2 so as to be movable up and down, and a sheet P of a predetermined size is placed on the lift plate 11. Is placed. A separation roller 41 is attached to the front side wall of the paper feed cassette C2. When the paper feeding cassette C2 is mounted on the paper feeding device main body FB, the elevating plate 11 is urged upward by a spring (not shown), and the uppermost paper of the paper P comes into contact with the pickup roller 40 (FIG. 4B). At the same time, the separation roller 41 comes into pressure contact with the feed roller 42 attached to the sheet feeder main body FB side.

  When paper is fed from the paper feed cassette C1, the paper P placed on the paper feed cassette C2 is pulled out in the direction of the transport path by the pickup roller 40, and the paper is fed one by one by the feed roller 42 and the separating roller 41. Supplied to the transport path. Then, the sheet P is sent to the registration roller 82 (shown in FIG. 1) through the conveyance roller pair 81. Since the distance from the nip portion of the feed roller 42 and the separating roller 41 to the nip portion of the conveyance roller pair 81 is short, the unit 2 having the conveyance roller 3 is not attached to the sheet feeding cassette C1, and the image forming apparatus main body The conveyance roller 43 is not attached to the MB.

  On the other hand, when paper is fed from the paper feed cassette C2, the pickup roller 40 pulls out the paper in the direction of the conveyance path, and the feed roller 42 and the separating roller 41 feed the paper P one by one to the conveyance path. This is the same as in the case of the paper feed cassette C1. The difference from the paper feed cassette C1 is that the paper P is further sandwiched and transported by the transport roller 3 of the unit 2 attached to the paper feed cassette C2 and the transport roller 43 attached to the paper feeder main body FB. is there. As a result, even for a small-sized sheet, a conveying force is applied to the sheet until the leading end of the sheet is nipped by the pair of conveying rollers 81, and the sheet is smoothly conveyed.

  The paper feed cassettes C1 and C2 can be attached to both the image forming apparatus main body MB and the paper supply apparatus main body FB. When the paper feed cassettes C1 and C2 are attached to the image forming apparatus main body MB, the transport roller 3 is not necessary. The unit 2 may be removed from the unit and used.

  When a plurality of paper feeding devices F are stacked and used, depending on the paper size placed on each paper feeding device, a paper feeding cassette that does not require the transport roller 3 may come out. In such a case, the unit 2 may be removed from the cassette body 1 for use. An example is shown in FIG.

  In the image forming apparatus shown in FIG. 5, one sheet feeding cassette C1 is attached to the image forming apparatus main body MB, and two sheet feeding apparatuses F1 and F2 are stacked below the image forming apparatus main body MB. As described above, the unit 2 is not attached to the paper feed cassette C1 attached to the image forming apparatus main body MB. A unit 2 is attached to a paper feed cassette C2 that stores paper of a small size. On the other hand, the unit 2 is not attached to the paper feeding cassette C3 of the paper feeding device F2. This is because the length of the paper stored in the paper feed cassette C3 in the conveyance direction is such that the conveyance roller 43 of the paper feed cassette C2 and the conveyance roller 3 from the nip portion of the feed roller 42 and the separation roller 41 of the paper feed cassette C3. Since the distance to the nip portion is longer than the distance between the nip portion and the feed roller 42 of the paper feed cassette C3 and the separation roller 41, the front end of the paper is in contact with the transport roller 43 of the paper feed cassette C2. It is because it is pinched by the conveyance roller 3. Of course, the size of the paper stored in the paper feed cassette C3 is small, and the length in the transport direction is such that the feed roller 42 of the paper feed cassette C3 and the nip portion of the separating roller 41 are connected to the transport roller 43 of the paper feed cassette C2. If it is shorter than the distance to the nip portion of the conveyance roller 3, the conveyance roller 3 is required, and the unit 2 is attached to the paper feed cassette C3.

  In the embodiment described above, the unit 2 to which the transport roller 3 is attached is attached to and detached from the cassette body 1. However, the transport roller 3 itself is attached to and detached from the cassette body 1 without using the unit 2. Of course. In this case, a conventionally known mechanism can be adopted as the attachment / detachment mechanism of the transport roller 3.

  In the above-described embodiment, the combination of the pickup roller 40, the feed roller 42, and the separation roller 41 is used as the mechanism for feeding the paper P from the paper feed cassette 1. However, for example, the feed roller 42 is provided and the front end of the paper feed side is provided. It is of course possible to provide a form in which separation claws are provided at the corners on both sides of the sheet and the both sides of the leading edge of the sheet are locked and the sheets are separated and fed one by one by the feeding force by the feed roller 42 and the resistance action by the separation claw. .

1 is a schematic diagram illustrating an example of an image forming apparatus using a paper feed cassette and a paper feed device according to the present invention. It is a perspective view which shows an example of the paper feed cassette which concerns on this invention. FIG. 3 is a perspective view of the sheet feeding cassette of FIG. 2 with a unit removed from the cassette body. FIG. 3 is a schematic diagram when the paper feeding cassette according to the present invention is attached to the paper feeding apparatus main body and the image forming apparatus main body. It is an outline figure in the case of using a paper feeder piled up. It is a schematic diagram which shows the usage example of the conventional paper feed cassette.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cassette main body 2 Unit 3 Conveyance roller 3a, 3b Conveyance roller C Paper feed cassette C1, C2, C3 Paper feed cassette F Paper feed device F1, F2 Paper feed device M Image forming device FB Paper feed device main body MB Image forming device main body

Claims (3)

In a paper feed cassette that is removably attached to an image forming apparatus main body and a paper feeding apparatus main body that can be expanded by stacking in a plurality of stages,
A paper feed cassette comprising a transport roller that is detachably provided in contact with a transport roller attached to the paper feed device main body when loaded into the paper feed device main body.   The paper feed cassette according to claim 1, wherein a unit to which the transport roller is attached is detachably provided.   A paper feeding device comprising the paper feeding cassette according to claim 1.

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