JP2007302360A - Paper sheet stacking device, and image forming device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet stacking device capable of ensuring a space above a paper delivery tray and realizing excellent alignment with a large inclination without reducing the number of stacked paper sheets and without increasing the size of the paper delivery tray, and an image forming device having the same. <P>SOLUTION: The paper sheet stacking device comprises a paper delivery tray 101 for receiving paper sheets to be delivered, and an auxiliary tray 102 with one end thereof being turnably supported by a rotary shaft 103 arranged on a rear end side of the delivered paper sheet, and the other end thereof being held in a vertically movable manner on the paper delivery tray 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet stacking apparatus that holds sheets discharged from a sheet discharge roller, and an image forming apparatus including the sheet stacking apparatus.

  A paper discharge tray of a conventional image forming apparatus has only a function of simply holding a sheet on which an image is formed. In order to save the user the trouble of aligning the paper later in this image forming apparatus, the functions of aligning the paper are to incline the paper discharge tray and make the paper fall height constant regardless of the number of sheets stored. There has been proposed a paper discharge stack device or the like having a pantograph configuration (see, for example, Patent Document 1).

Conventionally, the paper discharge tray has been arranged outside the image forming apparatus. However, in recent years, an inner tray type product arranged inside the image forming apparatus has been increasing in order to save space. Technical development has been made on whether to maintain the space or to improve the operability.
JP-A-5-254710

  However, in the above conventional configuration, the movable part of the pantograph mechanism has a complicated configuration, and the paper discharge tray becomes large. Further, since the image forming apparatus is also increased in size, there is a problem that a large space is occupied when the apparatus is installed. Further, the conventional configuration interferes with other parts due to vertical movement, so that a large inclination cannot be formed, and there is a problem that it is difficult to align the sheets discharged from the discharge rollers. In addition, a reading unit is generally arranged above the paper discharge tray. If the paper discharge tray is inclined to align the paper, the space between the paper reading unit and the reading unit is reduced, and the number of sheets stored is reduced. Thus, there is a problem that the operability is lowered.

  The present invention solves the above-described conventional problems, and ensures a space above the paper discharge tray, reduces the number of sheets stored, and does not increase the size of the paper discharge tray. It is an object of the present invention to provide an improved paper stacking apparatus and an image forming apparatus including the same.

  In order to solve the above problems, a sheet stacking apparatus and an image forming apparatus including the sheet stacking apparatus according to the present invention include a sheet discharge tray that receives discharged sheets, and a rotation shaft that is disposed on the rear end side of the discharged sheets. And an auxiliary tray having one end rotatably supported and the other end held so as to be movable up and down on the paper discharge tray.

  Therefore, since the large inclination is formed in the auxiliary tray, the sheet alignment becomes good, and the sheet stacking space is secured by moving up and down so that the accumulated number of sheets does not decrease.

  The sheet stacking apparatus and the image forming apparatus provided with the sheet stacking apparatus according to the present invention are configured such that the length from one end to the other end of the auxiliary tray is longer than ½ of the maximum sheet size length to be used. .

  Therefore, the sheet can be held and aligned at any sheet size up to the maximum sheet size length used by the auxiliary tray.

  Further, the paper stacking apparatus of the present invention and the image forming apparatus including the same are configured such that the rotation axis of the auxiliary tray is disposed at a position shorter than the minimum paper size length to be used from the discharge roller side. Is.

  Therefore, the sheet can be held and aligned at any sheet size up to the minimum sheet size length used by the auxiliary tray.

  The paper stacking apparatus and the image forming apparatus including the same according to the present invention are configured such that the other end of the auxiliary tray that can be moved up and down moves up and down according to the weight of the accumulated paper.

  Therefore, the auxiliary tray is lowered by the weight of the accumulated paper, so that a space above the paper discharge tray is secured and the number of accumulated paper sheets does not decrease.

  The sheet stacking apparatus of the present invention and the image forming apparatus including the same are provided with a leg portion at the other end of the auxiliary tray, and an L-shaped insulator for holding the leg portion, and one end coupled to the L-shaped insulator. The holding member is composed of the elastic member and a fixing member to which the other end of the elastic member is fixed.

  Therefore, the auxiliary tray is held at the top dead center when there is no accumulated paper, so that the inclination becomes large and the alignment of the paper is good, and the accumulated number does not decrease because it descends according to the number of accumulated paper. Have.

  The paper stacking apparatus and the image forming apparatus including the same according to the present invention have the above-described configuration, so that the auxiliary tray has a large inclination, so that the alignment of the paper is improved, and the paper tray is lowered by the weight of the discharged paper. As a result, the entire paper discharge tray space is secured even in a narrow space. In addition, this can prevent a decrease in the number of sheets stored. In addition, since the length to the other end of the auxiliary tray whose one end is supported on the rotation shaft is longer than ½ of the maximum paper size length to be used, the auxiliary tray can be used for any paper size to be used. It is possible to prevent the sheets from dropping and to accumulate them. Furthermore, since the rotation axis of the auxiliary tray is arranged at a position closer to the paper discharge roller side than the minimum paper size length to be used, the paper on the auxiliary tray can be used for any paper size used in the same manner as described above. Many functions and effects such as being able to accumulate the amount can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a paper stacking apparatus of the present invention and an image forming apparatus having the same.

  The image forming apparatus in FIG. 1 includes an image forming unit 1 that forms an image on a recording sheet through charging, exposure, development, transfer, and fixing processes, a paper feeding unit 2, a paper discharging unit 4, and a reading unit 20. And. A sheet (hereinafter referred to as a recording sheet) 3 is sequentially fed to the image forming unit 1 from a sheet feeding cassette of the sheet feeding unit 2 through a sheet feeding path A toward the image forming unit 1. The recording sheet 3 on which a required image is formed by the image forming unit 1 is discharged to the paper discharge unit 4 through a paper discharge path B from the image forming unit 1 to the outside of the apparatus.

  The image forming unit 1 has a tandem structure in which the photosensitive drums 5 a to 8 a of the respective colors are arranged along the intermediate transfer belt (intermediate transfer member) 10. That is, each color component of yellow (Y), magenta (M), cyan (C), and black (K) is placed under the intermediate transfer belt 10 as an image holding unit in which toner images of respective colors are sequentially transferred and combined. A plurality of process units 5 to 8 for forming a toner image, and a laser scanning unit that scans an image forming surface of each photosensitive drum 5a to 8a in each of the process units 5 to 8 with an exposure light beam. (Hereinafter referred to as LSU) 9.

  In the process units 5 to 8, an electrostatic latent image is formed by scanning an exposure light beam from the LSU 9 on the image forming surfaces of the photosensitive drums 5a to 8a uniformly charged by the chargers 5b to 8b. Then, the electrostatic latent images on the photosensitive drums 5a to 8a are developed with the toners of the respective colors supplied from the developing devices 5c to 8c, and single color toner images for the respective color components are formed on the image forming surfaces of the photosensitive drums 5a to 8a. Formed.

  The intermediate transfer belt 10 is supported by being wound around a driving roller 11 and a driven roller 12, and the intermediate transfer belt 10 is pressed on the inner side to transfer the toner images on the photosensitive drums 5 a to 8 a to the intermediate transfer belt 10. Primary transfer rollers 13 to 16 for the respective colors to be transferred to are provided. Further, a secondary transfer roller 17 for transferring the toner image on the intermediate transfer belt 10 to the recording sheet 3 is disposed on the side of the end of the intermediate transfer belt 10, that is, on the driving roller 11 side. The recording sheet 3 passes between the intermediate transfer belt 10 and the secondary transfer roller 17 on the drive roller 11 side, and a toner image is transferred by the secondary transfer roller 17. The recording sheet 3 to which the toner image has been transferred is conveyed to the fixing device 18 and is subjected to processing for fixing the toner image to the recording sheet 3 by heat and pressure. Thereafter, the recording sheet 3 is discharged onto the paper discharge unit 4 by the paper discharge roller 19 through the paper discharge path B. Reference numeral 20 denotes a reading unit, and a space on the paper discharge unit 4 is a space of an inner tray.

  In the paper discharge unit 4, a paper discharge tray 101 is fixed to the apparatus main body, and an auxiliary tray 102 is provided on the paper discharge tray 101. Reference numeral 103 denotes a rotating shaft, 104 denotes an L-shaped insulator, 105 denotes an elastic member, and 106 denotes a fixed object, which will be described in detail later.

  FIG. 2 is an enlarged cross-sectional view of the paper discharge unit 4 when there is no recording sheet 3 discharged from the image forming apparatus, and FIG. 3 is a diagram of the paper discharge unit 4 when the discharged recording sheets 3 are accumulated almost fully. It is an expanded sectional view.

  2 and 3, reference numeral 101 denotes a paper discharge tray that receives the recording sheet 3 that is formed and discharged, 102 denotes an auxiliary tray disposed above the paper discharge tray 101, and one end is arranged on the paper discharge tray 101. It is supported so that it can be rotated by a rotation shaft 103 provided. A leg 102 a provided at the other end C of the auxiliary tray 102 passes through the paper discharge tray 101 and is held by an L-shaped lever 104 that is rotatably supported and is provided at the bottom of the paper discharge tray 101. Has been. An elastic member 105 such as a spring is coupled to the other end of the L-shaped insulator 104, and the other end of the elastic member 105 is fixed to a fixed object 106 fixed to the apparatus main body. Therefore, the other end C of the auxiliary tray 102 when there is no discharged recording sheet 3 is held at the top dead center by the holding means including the L-shaped insulator 104, the elastic member 105, and the fixed object 106. Thus, the rotating shaft 103 is disposed with a large inclination from one end thereof.

  When the recording sheet 3 on which an image is formed by use of the image forming apparatus is discharged from the paper discharge roller 19, the recording sheet 3 discharged as shown in FIG. As a result, the recording sheet 3 is accumulated while aligning the rear end of the recording sheet 3. The other end C of the auxiliary tray 102 descends against the elasticity of the elastic member 105 due to the weight of the recording sheet 3 accumulated at this time, so that the space formed by the paper discharge tray 101 and the reading unit 20 is not narrowed. The recording sheets 3 that are effectively discharged can be used for accumulation. Accordingly, it is possible to prevent the number of recordable sheets 3 that can be accumulated in the formed space from decreasing, and after the discharged record sheet 3 is separated from the sheet discharge roller 19, the auxiliary tray 102 and the reading unit 20. Since the distance until the recording sheet 3 flies in the air is short, the recording sheet 3 is prevented from being disturbed, and the recording sheet 3 can be well aligned.

  The discharge tray 101 is formed with a recess or a notch corresponding to the shape of the auxiliary tray 102. When the number of discharged recording sheets 3 reaches a specified number as shown in FIG. It becomes the structure which fits into the recessed part or notch of this, and becomes flush. The rotating shaft 103 that supports one end of the auxiliary tray 102 is disposed on the paper discharge tray 101, but may be disposed on the image forming apparatus side.

  As shown in FIG. 4, the auxiliary tray 102 is formed longer than (1/2) × L with respect to the maximum sheet size length L of the recording sheet 3 to be used. The recording sheet 3 is prevented from dropping in the discharge direction of the recording sheet 3 beyond the auxiliary tray 102 in any paper size up to the length L.

  Further, in FIG. 4, the rotation shaft 103 that supports one end of the auxiliary tray 102 is arranged in the horizontal direction of the drawing at substantially the same position as the paper discharge roller 19. You may arrange | position to the position shorter than the minimum paper size length of the paper to be used from the position of the paper roller 19 to the left side of the drawing in the horizontal direction. Specifically, if the postcard paper (size is A6 size with 148mm in the vertical and 105mm in the horizontal) is the minimum paper, it should be shorter than 105mm for the lateral feed, but practically about 90mm about the discharge roller 19 side May be arranged at a position away from the paper discharge direction. That is, if the position of the rotation shaft 103 is within the minimum paper size length from the paper discharge roller 19 in the horizontal direction, even if the auxiliary tray 102 is shortened, the recording sheets 3 can be well aligned.

  In this embodiment, the elastic member 105 is a spring as a part of the holding means, but an elastic member other than the spring may be used. The elastic member 105 is adjusted so as to move up and down little by little according to the number of recording sheets 3 accumulated.

  The paper stacking apparatus and the image forming apparatus including the same according to the present invention improve the alignment of the paper discharged from the paper discharge roller and do not reduce the number of accumulated paper sheets, so that the image forming can effectively use the paper discharge tray space. It is useful as a device.

1 is a schematic configuration diagram illustrating a sheet stacking apparatus and an image forming apparatus including the sheet stacking apparatus according to an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of a paper discharge unit when there is no recording sheet discharged from the image forming apparatus according to the embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of a paper discharge unit when recording sheets discharged from an image forming apparatus according to an embodiment of the present invention are accumulated almost fully. FIG. 3 is an enlarged cross-sectional view showing the lengths of a recording sheet and an auxiliary tray of the image forming apparatus according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image formation part 2 Paper feed part 3 Recording sheet 4 Paper discharge part 5-8 Process unit 5a-8a Photosensitive drum 5b-8b Charger 5c-8c Developer 9 LSU
DESCRIPTION OF SYMBOLS 10 Intermediate transfer belt 11 Drive roller 12 Driven roller 13-16 Primary transfer roller 17 Secondary transfer roller 18 Fixing device 19 Paper discharge roller 20 Reading part 101 Paper discharge tray 102 Auxiliary tray 103 Rotating shaft 104 L-shaped lever 105 Elasticity Member 106 Fixed object

Claims (6)

One end of the paper discharge tray for receiving the discharged paper and a rotary shaft disposed on the rear end side of the discharged paper are rotatably supported, and the other end can be moved up and down on the paper discharge tray. A paper stacking device comprising a held auxiliary tray. 2. The paper stacking apparatus according to claim 1, wherein a length from one end of the auxiliary tray to the other end is longer than ½ of a maximum paper size length to be used. 2. The paper stacking apparatus according to claim 1, wherein the rotation axis of the auxiliary tray is disposed at a position shorter than a minimum paper size length to be used from the paper discharge roller side. 2. The paper stacking apparatus according to claim 1, wherein the other end of the auxiliary tray that can be moved up and down moves up and down according to the weight of the accumulated paper. A leg portion is provided at the other end of the auxiliary tray, an L-shaped insulator for holding the leg portion, an elastic member having one end coupled to the L-shaped insulator, and a fixing in which the other end of the elastic member is fixed 2. The sheet stacking apparatus according to claim 1, further comprising a holding unit including a member. An image forming apparatus comprising the paper stacking device according to claim 1.

Images