JP4956280B2 - Paper feeding cassette and image forming apparatus - Google Patents

Description

  The present invention relates to a paper feed cassette and an image forming apparatus, and more particularly, to a paper feed cassette that is mounted on an image forming apparatus and stores printing paper, and an image forming apparatus including the paper feed cassette.

  The electrophotographic image forming apparatus can form an image on the surface, an image forming unit that can form an image on a sheet based on image information, a fixing unit that fixes the image formed on the image forming unit on the sheet, and the like. A sheet feeding unit for storing a sheet of paper and a sheet conveying unit for conveying the sheet to the image forming unit and the fixing unit. In this image forming apparatus, a sheet fed from a sheet feeding unit is conveyed to the image forming unit, and an image is formed on the sheet based on image information by the image forming unit. The sheet on which the image is formed on the surface by the image forming unit is conveyed to the fixing unit by the sheet conveying unit, and the image is fixed on the sheet by the fixing unit. The sheet on which the image is fixed on the sheet by the fixing unit is discharged to the outside of the image forming apparatus.

Here, the paper feed unit has a paper feed cassette that can store printing paper, a roller for paper feed, and the like. The paper feed cassette includes a placement plate capable of placing paper, a pair of support plates capable of supporting both sides of the paper in the width direction, and a frame and width alignment plate capable of supporting both sides of the paper in the longitudinal direction. Have. Here, the width adjusting plate is a plate-like member that can be adjusted in width according to the size of the paper (see Patent Document 1). Here, some support plates are formed so that projecting portions for supporting the paper project in a direction substantially orthogonal to the pair of support plates.
JP-A-11-139572

  In such a paper feeding cassette, when the paper is set in the paper feeding cassette, the paper is placed between the pair of support plates from above. And width alignment is performed with a width alignment board. Here, when the paper is set in the paper feed cassette, the paper may be placed between the pair of support plates so that the paper slides between the pair of support plates. In such a case, it is difficult to place the paper because the paper is caught by the protruding portion.

  An object of the present invention is to make it difficult for a sheet to be caught by a protruding portion.

Sheet feeding cassette of the image forming apparatus according to claim 1 is mounted on the image forming apparatus, a paper feed cassette for accommodating paper for printing, a sheet placing plate of the paper is placed, the sheet mount and a support plate of a pair for supporting the widthwise sides of the placed paper plate, each of the support plates of said pair, perpendicular to the sheet width direction and having a predetermined height A side portion that extends in the paper transport direction and faces the side of the paper, and a support protrusion that protrudes from the side toward the paper and is linearly formed in the vertical direction and can contact the side of the paper. The side of the side facing the side of the sheet is inclined so as to gradually move away from the sheet side with a draft of the mold from the bottom upward while leaving the support protrusion. The insertion guide side surface on the upstream side in the paper insertion direction of the protrusion is the support protrusion upward. The support protrusion is inclined from the sheet contact surface to the side with a draft angle of the mold in a direction in which the width of the support protrusion decreases, and the side surface of the support protrusion on the downstream side in the sheet insertion direction is upward from the bottom. It is characterized by being inclined with a draft angle of the mold.

  In the paper feed cassette of this image forming apparatus, when replenishing printing paper, the paper is placed on a paper placement plate, and both ends of the paper in the width direction are supported by a pair of support plates. At this time, the paper is placed on the paper placement plate from above and between the pair of support plates. Alternatively, when the paper is placed on the paper placement plate, the paper is placed between the pair of support plates by inserting the paper from the upstream side in the paper insertion direction. Here, the paper insertion direction refers to the direction behind the pair of support plates in the paper transport direction and from the upper side of the pair of support plates to the space between the pair of support plates. For this reason, when a sheet is inserted from the upstream side in the sheet insertion direction, the sheet slides between a pair of support plates. At this time, the insertion guide side surface on the upstream side in the paper insertion direction of the support protrusion is inclined from the paper contact surface of the support protrusion to the side, so that the paper can be prevented from being caught by the support protrusion. It becomes easy to insert.

An image forming apparatus according to claim 2 is provided with a paper feed cassette according to claim 1, an image forming unit for forming an image on a sheet stored in the sheet feeding cassette, a.

  In the present invention, it is possible to make it difficult for the sheet to be caught by the protruding portion.

1. Overall Configuration FIG. 1 shows a color printer 1 as a color image forming apparatus according to an embodiment of the present invention. FIG. 1 is a schematic diagram for showing the arrangement of each component, and details of each part are omitted.

  The color printer 1 is connected to a computer (not shown) or the like, and is a device that can print a color image on paper based on image information sent from the computer or the like. In the color printer 1, the right side in FIG. 1 is the side operated by the operator, and in the following, the right side of the apparatus in FIG. 1 is the front side and the left side is the back side.

  The color printer 1 includes an image forming unit 2 that forms a toner image, a toner replenishing unit 23 that supplies toner to the image forming unit 2, a fixing unit 4 that fixes an image formed by the image forming unit 2 to a sheet, And a paper transport unit 5 for transporting paper from the paper feed unit 6 to the image forming unit 2 and the fixing unit 4.

  The image forming unit 2 includes a rotary developing device 10, a photosensitive drum 11 disposed in the vicinity of the rotary developing device 10, a laser unit 12 that irradiates the photosensitive drum 11 with a laser, and an intermediate that contacts the photosensitive drum 11. A transfer belt 13 and a secondary transfer roller 14 are included.

  The rotary developing device 10 includes a rotary frame 15 and four developing devices 16 provided corresponding to the four color toners and supported by the rotary frame 15. The rotary frame 15 has a cylindrical shape that is rotatable around an axis parallel to the rotation axis of the photosensitive drum 11 and is rotated by a drive mechanism including a motor and a gear (not shown). The rotating frame 15 has four sections divided into four equal in the circumferential direction by a partition frame extending radially from the center of the rotating shaft, and each section has four toners of yellow, cyan, magenta, and black. A developing device 16 corresponding to the color is arranged.

  The developing device 16 is a portion for supplying toner to the photosensitive drum 11. Each developing device 16 has substantially the same configuration, and includes a developing roller 17, a toner container 18 as a developing device housing, and a toner supply roller 19.

  The developing roller 17 is a member for supplying toner to the photosensitive drum 11 and has a metal cylindrical portion and an elastic portion provided around the cylindrical portion. The developing roller 17 is disposed at a distance from the photosensitive drum 11.

  The toner storage container 18 is a part for storing toner therein, and has an opening and a toner stirring member disposed inside. The toner container 18 rotatably supports the developing roller 17. Further, the opening is opened along the axis of the developing roller 17 so that a part of the developing roller 17 is exposed to the photosensitive drum 11 side.

  The toner supply roller 19 is disposed inside the toner container 18 so as to be in contact with the developing roller 17 and is a cylindrical member having a surface formed of a sponge material.

  The photosensitive drum 11 has an electrostatic latent image formed on the surface thereof, and is rotatably provided in the center of the apparatus. The rotation axis of the photosensitive drum 11 extends in the lateral direction when viewed from the front side of the apparatus. It is provided so as to extend perpendicular to the paper surface of FIG. Further, the photosensitive drum 11 is disposed with a gap from the developing roller 17. Further, a drum cleaning device for cleaning toner and adhering matter remaining on the surface of the photosensitive drum 11 is provided on the side of the photosensitive drum 11.

  The laser unit 12 scans and exposes the photosensitive drum based on image information sent from an external computer or the like. The internal configuration of the laser unit 12 is the same as the conventional configuration, and includes a laser light source, a polygon mirror, a polygon mirror driving motor, and the like. A reflection mirror is provided in front of the laser beam path of the laser unit 12. Therefore, as indicated by the one-dot chain line in FIG. 1, the laser light emitted from the laser unit is bent by the reflection mirror, passes above the front side of the rotary developing device 10, and is irradiated onto the surface of the photosensitive drum 11. It has come to be.

  The intermediate transfer belt 13 sequentially transfers the toner images of the respective colors formed on the photosensitive drum 11, and is hung between the driving roller and a driven roller urged away from the driving roller by a spring. Has been passed. Further, the portion of the transfer belt 13 that faces the photosensitive drum 11 is configured to contact the photosensitive drum 11 by a pair of primary transfer rollers 26a and 26b.

  The secondary transfer roller 14 is for transferring the image transferred to the intermediate transfer belt 13 onto the conveyed paper, and is disposed below the drive roller so as to face the drive roller.

  The toner replenishing unit 23 includes a toner container 24 provided therein with toner to be replenished to the toner container 18 and a toner replenishing device 25 for replenishing the toner container 18 with toner.

  The toner container 24 is a box-like member having toner therein, and is disposed above the front side of the rotary developing device 10.

  The toner replenishing device 25 is for supplying the toner in the toner container 24 to the toner container 18, and includes a toner replenishing pipe that supplies toner and a toner transport unit that transports the toner.

  The fixing unit 4 is for fusing and fixing the toner transferred onto the paper, and is disposed below the rotary developing device 10 and on the back side of the device. The fixing unit 4 includes a heating roller having a built-in heater and a pressure roller that is in pressure contact with the heating roller.

  The paper feed unit 6 is disposed below the color printer 1 and has a plurality of paper feed cassettes 7 capable of storing papers for each type of paper, rollers for supplying papers to the paper transport unit, and the like. And have. Here, the paper feed cassette 7 will be described in detail later.

  The paper transport unit 5 is a part for transporting the paper in the paper feed cassette to the image forming unit 2 and the fixing unit 4.

2. Paper Feed Cassette The paper feed cassette 7 is a member that can store paper and is disposed in the paper feed unit 6. As shown in FIG. 2, the paper feed cassette 7 includes a frame 71, a pair of support plates 72, and an alignment plate 74.

  The frame 71 is a box-shaped member, and includes a sheet placement plate 711, a first wall portion 712, a second wall portion 713, a third wall portion 714, and a fourth wall portion 715. ing. The frame 71 has a roller 716 for facilitating pulling out from the color printer 1 on the back side of the color printer 1. The paper placement plate 711 is a portion disposed on the bottom surface of the frame 71, on which paper is placed. Here, the sheet can be fed to the sheet transport unit 5, specifically, between the pair of support plates 72 and between the alignment plate 74 and the third wall portion 714 of the frame 71. Placed. The first wall portion 712 is a portion provided on the front side of the color printer 1, and a handle 712 a that can be gripped when being pulled out from the color printer 1 is formed. The second wall portion 713 is disposed so as to face the first wall portion 712 and is a portion located on the back side of the color printer 1. The third wall portion 714 is a portion disposed between the first wall portion 712 and the second wall portion 713, and a support surface 714a that supports the end portion in the longitudinal direction of the sheet is formed. The fourth wall portion 715 is disposed between the first wall portion 712 and the second wall portion 713 and is a portion disposed so as to face the third wall portion 714.

  The pair of support plates 72 are members that support both sides of the sheet, specifically, both ends in the direction orthogonal to the longitudinal direction (the width direction of the sheet), and are provided so as to be movable in the width direction of the sheet. Further, the pair of support plates 72 has a bottom 721 and a support portion 722 (side portion). The bottom 721 is a portion that contacts the paper placement plate 711 and is a portion on which a part of the paper can be placed. The paper is placed on the paper placement plate 711 in parallel with the paper placement plate 711 and slidable in the paper width direction with respect to the paper placement plate 711. The support portion 722 is provided in a direction substantially orthogonal to the bottom portion 721, and is formed obliquely so that the surface on the side facing the sheet gradually moves away from the sheet side from the bottom portion 721. Further, the support portion 722 has a support protrusion 73. The support protrusion 73 is a part for supporting the paper at the tip, and is a part that protrudes from the support part 722 of the pair of support plates 72 toward the paper when the paper is placed on the paper placement plate 711. is there. Moreover, the support protrusion 73 is formed in the whole vertical direction of the support part 722, and the protrusion side front-end | tip position is the same without changing with height positions. Here, as described above, the surface of the support portion 722 facing the sheet is formed obliquely so as to gradually move away from the sheet side from the bottom portion 721, so that it faces upward in the vertical direction as shown in FIG. The amount of protrusion gradually increases. Thus, the mold has a draft angle upward from the bottom 721. Further, a plurality of support protrusions 73 are arranged at equal intervals in the direction in which the support plate 72 extends. Of the support protrusions 73, the three support protrusions 73 located on the third wall 714 side have a contact surface 731 and a tapered surface 732 (side surface for insertion guide) as shown in FIG. ing. The contact surface 731 (paper contact surface) is provided at the front end of the support protrusion 73 in the protrusion direction, and is a surface facing the side of the paper. The contact surface 731 is formed so that the width gradually decreases upward in the vertical direction, and is formed flat and smooth. In this way, the die has a draft angle upward from the bottom 721. The tapered surface 732 is formed to make it difficult to catch the support protrusion 73 when the paper is slid between the pair of support plates 72 and inserted into the paper placement position. It is formed on the side surface on the part 715 side. Further, the tapered surface 732 is formed so as to gradually become inclined upward in the vertical direction. Specifically, the tapered surface 732 is provided so as to incline from the front end in the projecting direction of the support projecting portion 73 to the support portion 722.

  The alignment plate 74 is a member for accurately placing the paper at the paper placement position, and is slidably disposed between the third wall portion 714 and the fourth wall portion 715. The alignment plate 74 is a member that extends in a direction substantially orthogonal to the paper placement plate 711 and is a portion that supports one end of the paper in the longitudinal direction.

3. Operation In this color printer 1, when image information is sent from an externally connected computer or the like, an electrostatic latent image is formed on the photosensitive drum 11 based on the sent image information. Toner is supplied from the developing device 16 to the electrostatic latent image formed on the photosensitive drum 11, and a toner image is formed on the photosensitive drum 11. This toner image is transferred to the intermediate transfer belt 13. At this time, the paper is conveyed from the paper supply unit 6 to a position where it contacts the intermediate transfer belt 13, and the toner image on the intermediate transfer belt 13 is transferred to the paper. The sheet on which the toner image is transferred is conveyed to the fixing unit 4 and the toner image is fixed on the sheet. The sheet on which the toner image is fixed is discharged outside the color printer 1.

  Here, the operation of replenishing paper into the paper feed cassette 7 will be described.

  When paper is replenished to the paper feed cassette 7, the handle 712 a of the first wall portion 712 of the paper feed cassette 7 is gripped, and the paper feed cassette 7 is pulled out to the front side of the color printer 1. Then, the pair of support plates 72 are adjusted according to the size of the sheet, and the sheet is inserted between the pair of support plates 72 from above. Alternatively, the sheet is inserted between the pair of support plates 72 from the upper side of the pair of support plates 72 and into the fourth wall portion 715 side, and the pair of sheets is supported toward the third wall portion 714 side. It is mounted by sliding between the plates 72. Thereafter, alignment is performed by the alignment plate 74.

Here, the sheet is inserted between the pair of support plates 72 from the upper side of the pair of support plates 72 and on the fourth wall portion 715 side, and the sheet is paired toward the third wall portion 714 side. When the paper is placed by being slid between the support plates 72, the paper is less likely to be caught by the support protrusion 73. For this reason, it becomes easier to place the paper on the paper placement plate 711 .

4). Other Embodiments (a) Although the color printer 1 has been described in the above embodiment, the present invention is not limited to this, and may be a copying machine or a multifunction machine.

  (B) Moreover, in the said embodiment, although the taper surface 732 is formed only in three by the side of the 3rd wall part 714 among the support protrusion parts 73, this invention is not restricted to this, All support protrusion parts A tapered surface 732 may be formed on 73.

1 is an overall schematic diagram of a color printer 1. FIG. The whole perspective view of a paper feed cassette. The figure when the support plate of a paper feed cassette is seen from the upper side. The figure when the support plate of a paper feed cassette is seen from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color printer 2 Image formation part 7 Paper feed cassette 72 Support plate 73 Support protrusion part 74 Position alignment board 711 Paper mounting board 714a Support surface 722 Support part (side part)
731 Contact surface (paper contact surface)
732 Tapered surface (side surface for insertion guide)

Claims (2)

A paper feed cassette that is mounted on an image forming apparatus and stores printing paper,
A paper placement plate on which the paper is placed;
A pair of support plates for supporting both sides in the width direction of the paper placed on the paper placement plate;
With
Each of the pair of support plates has a predetermined height and extends in a sheet conveying direction orthogonal to the sheet width direction and faces a sheet side, and protrudes from the side toward the sheet. A support protrusion that is linearly formed in the vertical direction and that can contact the side of the paper,
The side of the side facing the side of the sheet is inclined so as to gradually move away from the sheet side with a draft angle of the mold upward from the bottom, leaving the support protrusion.
The insertion guide side surface upstream of the support protrusion in the sheet insertion direction has a die draft in a direction in which the width of the support protrusion narrows upward, and the sheet contact surface of the support protrusion To the side,
A sheet feeding cassette of an image forming apparatus, wherein a side surface of the supporting protrusion on the downstream side in the sheet insertion direction is inclined with a die draft from the bottom toward the upper side . A paper feed cassette according to claim 1 ;
An image forming unit that forms an image on paper stored in the paper cassette;
An image forming apparatus.

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