JP2007182320A - Sheet material feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet material feeding device having simple construction for a feed cassette to be turned within a limited device width, and to provide an image forming device. <P>SOLUTION: For space saving, a carrying guide part 13 is constructed to be set aside in linkage with the turn of the feed cassette 7. The turning center of the feed cassette 7 is optimally arranged in the image forming device and the turning track of the feed cassette 7 is not greater than the width of a device body to minimize the turning occupied area of the feed cassette, which is the substantial size of the device. When opened, the feed cassette is located lower than when stored. It has simple construction for relaxing shock when closed. The turning center of the feed cassette 7 is integrated with the frame of the device body, compatibly attaining high rigidity and high accuracy. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet material feeding device for supplying a sheet material to an image forming apparatus such as a copying machine or a printer.

  A sheet material feeding apparatus of a system (hereinafter referred to as a front loading system) in which a sheet feeding cassette in which sheet materials (paper sheets) are stacked and stored is inserted into and removed from a direction perpendicular to the sheet feeding direction in the apparatus. Various proposals have been made.

  For example, in Japanese Patent Laid-Open No. 2003-260260, a paper feeding apparatus that inserts and mounts and pulls out a paper feeding cassette in which sheet materials are stacked and stored from a direction perpendicular to the paper feeding direction in the apparatus is connected to the paper feeding cassette. A lateral registration and positioning configuration of the paper roller and the main body device is disclosed.

  A paper feed cassette that rotates toward the front side of the apparatus is also disclosed. For example, Patent Document 2 describes a configuration in which an insertion port leading to a cassette mounting chamber is provided in a region extending over both the front and side surfaces of the device main body. Further, a guide groove that is curved inward from the insertion port is provided on the bottom surface of the cassette mounting chamber, and a slider that slides along the guide groove is provided on the bottom surface of the cassette. Then, by providing a guide rail that curves inward from the insertion opening and a rolling element that rolls along the guide rail on the bottom surface of the cassette, downsizing and improved operability are achieved.

In Patent Document 3, the sheet material feeding device is pulled out to the front side, and further rotated to open the front side of the apparatus main body. Thus, the replenishment of the sheet material and the removal of the paper jam in the paper conveyance path can all be performed in the space on the front surface of the apparatus main body, thereby reducing the size and improving the operability.
JP-A-7-223744 JP-A-4-246030 Japanese Patent Laid-Open No. 11-11699

  However, in Patent Document 1, since it is configured to be movable in a direction orthogonal to the sheet feeding direction, when a large number of sheet materials are stacked, the cassette is inserted in the direction orthogonal to the inertia of the sheet material during the cassette insertion operation. It moves slightly. Therefore, although an adjustment mechanism is provided, there is a problem that positioning is not performed accurately and stably due to the number of sheets and the user's operating force. In addition, there is a problem that the cost is increased due to the complicated parts by the adjusting mechanism.

  In Patent Document 2, since a guide rail and rolling elements are required to reduce the locus when the cassette is attached and detached, there is a problem of an increase in cost. Furthermore, a part of the outer frame of the apparatus main body in the area where the cassette moves is cut out, which reduces the rigidity of the apparatus. If the rigidity is low, the accuracy between the functional components cannot be stably maintained, and problems such as image defects and a shortened life may occur.

In Patent Document 3, a rail for pulling out to the front side and parts of a lock mechanism are required, and there is a problem that costs increase. Further, in the technique described in Patent Document 3, since a large number of parts are interposed, there is a problem that the positioning accuracy of the sheet material is deteriorated as in Patent Document 1.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet material feeding device and an image forming apparatus that can rotate a paper feed cassette with a simple configuration and a limited width of the device.

  In order to achieve the above object, the present invention comprises a sheet feeding cassette for stacking sheet materials, and a transport unit for transporting sheet materials fed from the sheet feeding cassette. A sheet material feeding device that is rotatably supported and can be pulled out of the main body of the apparatus by rotating the paper feed cassette, and is interlocked with a rotation operation when the paper feed cassette is pulled out. The transport unit is configured to be retracted.

  According to the present invention, there is no need for complicated and many parts such as a slide rail or a positioning lock mechanism, and the simple and low-cost configuration is limited by retracting the conveyance unit in conjunction with the rotation of the cassette. The cassette can be rotated by the width of the apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a cassette pulling mechanism of a sheet material feeding apparatus according to the first embodiment of the present invention. FIG. 2 shows the entire image forming apparatus including the sheet material feeding apparatus according to the first embodiment of the present invention.

  As shown in FIG. 2, reference numeral 1 denotes an image forming apparatus. The image forming apparatus 1 includes a sheet material feeding device A and an image forming unit 2 that forms an image on the sheet material fed by the sheet material feeding device A. The sheet material feeding apparatus A is disposed at the lower part, the image forming unit 2 is disposed thereon, and the image reading unit 3 for reading the image of the document is disposed thereon.

  The sheet material feeding apparatus A includes upper and lower two-stage sheet feeding cassettes 7 and 8 on which a large number of sheet materials are stacked. The sheet bundles stacked in the sheet feeding cassettes 7 and 8 are separated and fed one by one, guided by the conveyance roller 6, and proceed to the image forming unit 2. The sheet bundle forms an image on the sheet material 16 in the image forming unit 2 and is discharged onto the discharge tray 4 by the discharge roller 5.

  The paper feed cassettes 7 and 8 are selectively used depending on the size of the sheet material 16. In this embodiment, it is a two-stage cassette, but the number of stages is not limited to this. Further, here, the paper feed cassettes 7 and 8 are configured to be drawable toward the front side of the image forming apparatus.

  FIG. 1 shows a sheet feeding cassette pulling mechanism of the sheet material feeding apparatus most characteristic in the present invention. FIG. 1 is a schematic top view of the upper sheet cassette 7. Since the lower sheet cassette 8 has the same configuration, it is not particularly shown, and the upper sheet cassette 7 will be described in the following description.

That is, the sheet material feeding apparatus A includes a sheet feeding cassette 7 on which the sheet material 16 is stacked, and a conveyance guide unit 13 that constitutes a conveyance unit that conveys the sheet material 16 fed from the sheet feeding cassette 7. Yes. The paper feed cassette 7 is supported so as to be rotatable about the guide fulcrum shaft 20 with respect to the apparatus main body, and the paper feed cassette 7 can be opened and stored by rotating the paper feed cassette 7. .

  The paper feed cassette 7 has a bowl-like frame configuration, and a plurality of sheet materials 16 are placed inside the paper feed cassette 7 and a pair of side guides for guiding the side end face in the paper feed direction. 17 and 18 are arranged. As shown in FIG. 7, the side guides 17 and 18 can be slidably linked by a pinion gear 36 via rack gears 37 and 38. Further, a slidable rear end guide 19 for guiding the rear end surface of the sheet material 16 is disposed.

  The guide fulcrum shaft 20 is formed on a part of the bottom lower surface of the paper feed cassette 7. The position of the guide fulcrum shaft 20 is disposed on the sheet material center line N parallel to the sheet material conveyance direction inside the apparatus main body.

  In the first embodiment, it is arranged near the end portion in the sheet feeding direction. The position of the guide fulcrum shaft 20 corresponds to the image center (center in the main scanning direction) of the image forming unit 2, and the positional accuracy with respect to the side guides 17 and 18 is also guaranteed.

  The guide fulcrum shaft 20 is supported by a bearing portion 32 formed from a frame of the image forming apparatus main body. The bearing unit 32 is also guaranteed in positional accuracy with respect to the image center (main scanning direction center) of the image forming unit 2. The bearing portion 32 is partially open, and wall-shaped guides 23 and 31 are formed in the opening so that the front side is continuously opened, and has a bell shape as a whole.

  The guide fulcrum shaft 20 has a two-sided cut shape having a pair of parallel cut surfaces, and the paper feed cassette 7 is positioned at the home position (solid line) where the paper feed cassette 7 is accommodated in the image forming apparatus. Fixed.

  At the position where the paper feed cassette 7 is rotated about 90 degrees (two-dot broken line), the two-sided width cut shape is also rotated 90 degrees, and the minimum width portion sandwiched between the cut surfaces coincides with the opening of the bearing portion 32. Comes out of position. By arranging the guide fulcrum shaft 20 inside the apparatus, the turning radius of the paper feed cassette 7 is reduced, and the swirling occupation area is kept to a minimum.

  In particular, by disposing at the sheet material center, the swiveling occupation area of the sheet feeding cassette 7 can be kept to a minimum, and the apparatus can be substantially downsized. In the first embodiment, the guide fulcrum shaft 20 is close to the sheet feeding side, but the guide fulcrum shaft 20 is not limited to the sheet feeding side. can get.

  Further, the outer frame 1a (shaded area in the figure) forming the apparatus main body of the image forming apparatus 1 is formed outside the swivel area of the paper feed cassette 7, but can be formed without cutting out the side. , Maximum rigidity in a limited space. The outer frame of the shaded area is made of synthetic resin or metal, maintaining the accuracy between functional parts for image formation, such as rollers and photosensitive drums (not shown), and has the effect of stable image formation and long life. is there.

  Rollers 21 and 22 are disposed on the rear end side of the sheet feeding cassette 7 in the sheet feeding direction, and roll on the main body frame 1b when the sheet feeding cassette 7 is rotating. The roller shafts 21a and 22a are inclined so that the rollers 21 and 22 face the guide fulcrum shaft 20. At the home position of the paper feed cassette 7, the rollers 21 and 22 are positioned above the slopes 29 and 33 provided on the main body frame 1b.

An auxiliary cover 9 is disposed on the opposite side of the paper feed cassette 7 in front of the apparatus. The auxiliary cover 9 rotates together with the cover ring about a reference numeral 11 and is usually present at a solid line position in the drawing by a spring (not shown).

  At the same time as the paper feed cassette 7 rotates, the auxiliary cover 9 also rotates. A guide roller 12 is disposed at the tip of the auxiliary cover 9, and when the auxiliary cover 9 rotates, the conveyance guide unit 13 is moved. The conveyance guide unit 13 includes rotation fulcrum shafts 14 and 15 and is usually located at a solid line position in the drawing by a spring (not shown).

  FIG. 3 shows the paper feed cassette 7 from the front of the apparatus. As shown in FIG. 3, a plurality of sheet materials 16 are placed on the paper feed cassette 7, and a pick roller 24 for picking from the upper part, a separation roller 25 for separating and feeding paper one by one, and opposing positions. A separation pad 26 is arranged on the surface, and a predetermined separation pressure is generated by a spring 27.

  When the sheet is separated and fed, the sheet advances to the conveyance guide unit 13 and is guided to the upper conveyance roller 6 through a path 13a curved upward. The conveyance guide unit 13 is also formed with a vertical path 13b for guiding a sheet material from the lower sheet cassette 8 to form a merge path. The conveyance guide unit 13 is rotatable about the rotation fulcrum shaft 15 at the lower end from the vertical state to the horizontal state in the direction of reference numeral 28. For example, when the sheet cassette 7 is pulled out to replenish the sheet material 16 in the sheet cassette 7, the auxiliary cover 9 is rotated in conjunction with the rotation of the sheet cassette 7, and the conveyance guide unit 13 is retracted. So as to rotate downward. Therefore, the conveyance guide unit 13 does not interfere with the paper feed cassette 7 and the auxiliary cover 9.

  In the first embodiment, the conveyance guide unit 13 is retracted by interlocking with the paper feed cassette 7. Note that not only the conveyance guide unit 13 but also the conveyance roller 6 may be retracted simultaneously. Further, the retracting portion of the transport guide portion 13 can be configured to be partially retracted only in the region on the near side in the main operation direction. That is, at least a portion of the transport unit that interferes with the rotation locus of the sheet feeding cassette is retracted in conjunction with the rotation operation when the sheet feeding cassette 7 is pulled out.

  FIG. 4 shows a position where the paper feed cassette 7 is rotated about 45 degrees. In a state where the auxiliary cover 9 is interlocked and the conveyance guide portion 13 is retracted, the area on which the sheet material 16 is placed is not exposed at this position, but the side guide 18 on the front side can be operated sufficiently. Has been pulled out. If the side guide 18 is operated, the back side of the side guide 17 is interlocked with the above-described rack and pinion mechanism, so that it is not necessary to operate the side guide 17 located on the back side, and the minimum required for operation. Space.

  Further, since the rear end guide 19 is also pulled out to the near side, it can be fully operated. Regarding the replenishment and removal operation of the sheet material 16, although it is A3 size in the drawing, since the substantially central part of the sheet material bundle comes out of the apparatus, it can be replenished and can be operated by the user with a minimum space. In addition, a small-sized sheet, for example, A4 size or B5 size, can be operated with one hand, so that it is a sufficient operation space. In particular, in order to place the sheet material 16, the entire surface of the sheet cassette 7 is not pulled out and exposed outside the apparatus, and the area occupied by the apparatus body is minimized by optimizing the rotation center position of the sheet cassette 7. Can be suppressed.

FIG. 5 shows a position where the paper feed cassette 7 is rotated by about 90 degrees. Since the position shown in FIG. 5 is a position where the guide fulcrum shaft 20 of the paper feed cassette 7 is disengaged from the bearing portion 32, the paper feed cassette 7 can be attached and detached by insertion and removal. This position is the maximum opening position of the paper feed cassette 7. Normally, the user does not open the paper feed cassette 7 up to this position. However, at the time of manufacturing assembly and service maintenance, it is necessary to rotate to this position, and the paper feed cassette 7 can be pulled out in the direction of reference numeral 35 as shown in FIG. On the contrary, when the paper feed cassette 7 is inserted, the wall-shaped guides 23 and 31 have a bell-shaped shape so that the guide fulcrum shaft 20 at the end of the bearing portion 32 can be guided.

  FIGS. 8 to 10 show detailed left side partial views showing the guide fulcrum shaft 20 and the bearing portion 32 of the paper feed cassette 7. FIG. 8 shows the paper feed cassette 7 in the home position, and the guide fulcrum shaft 20 is positioned by the bearing portion 32. A protrusion 34 is disposed in the vicinity of the guide fulcrum shaft 20 and is in contact with the upper surface of the wall of the bearing portion 32. The protrusion 34 can move on the guide cam surface 39 that forms the upper surface of the wall of the bearing portion 32 and the inclined surface by the rotation of the paper feed cassette 7. Therefore, the position in the height direction of the paper feed cassette 7 at the home position in FIG. 8 is determined by the projection 34 being placed on the upper surface of the wall of the bearing portion 32.

  FIG. 9 shows a state in which the paper feed cassette 7 is rotated 45 degrees. As shown in FIG. 9, the projection 34 is placed on the guide cam surface 39 of the slope. That is, the operation of opening the paper feed cassette 7 moves the paper feed cassette 7 downward in the height direction. On the contrary, in the operation of closing the paper feed cassette 7, the paper cassette 7 moves upward as it closes and settles to the home position. Since the sheet cassette 7 moves upward as the sheet cassette 7 is closed, an operation reaction force is generated, which has an effect of reducing the impact when the sheet cassette 7 is closed, and has a damper function. By reducing the impact, the bundle of the sheet material 16 is not displaced due to the inertia of the bundle of the sheet feeding cassette 7 and the sheet material 16 and can be accurately positioned.

  Further, the position of the guide fulcrum shaft 20 corresponds to the position substantially at the center of the sheet material size, and the positional accuracy with respect to the side guides 17 and 18 is guaranteed. The bearing unit 32 is also guaranteed in positional accuracy with respect to the image center (main scanning direction center) of the image forming unit 2. Therefore, it is possible to achieve low cost and complete no adjustment with a simple configuration without requiring a horizontal registration adjusting mechanism according to the prior art. Since the sheet material center and the guide fulcrum shaft 20 whose position is guaranteed are on the same line, the accuracy is guaranteed.

  In the first embodiment, an operation reaction force is generated when the sheet feeding cassette 7 is closed by its own weight, and the damper function is used. As the damper function, a dedicated damper such as a spring, a rubber damper, an oil damper, or the like is used. May be configured such that an operation reaction force acts just before closing.

  FIG. 10 shows a state in which the paper feed cassette 7 is rotated 90 degrees, and a protrusion 34 is placed on a plane lower than the home position. This position is the lowest position where the sheet cassette 7 can move in the height direction. This is a position where the paper feed cassette 7 can be inserted / removed. When the paper feed cassette 7 is inserted / removed, the protrusion 34 below the paper feed cassette moves while sliding on the upper surface of the guide 23 of the bearing. During a normal user operation, even if the paper feed cassette 7 is wide open, it is up to about 60 degrees. The paper feed cassette 7 is not detached by the above-described mechanism, and the paper feed cassette 7 is not accidentally dropped. Since the paper feed cassette 7 can be inserted and removed only at the 90 degree position, reliability and maintainability are improved.

  FIG. 11 shows a detailed view of the rollers 21 and 22 of the paper feed cassette 7. As shown in FIG. 11, the rollers 21 and 22 are driven to rotate by the rotation operation of the paper feed cassette 7, and the operation force of the paper feed cassette 7 is reduced. Further, the closing operation raises the slope 29, and the roller 21 settles on the dent 30 (lock mechanism). The position at which the dent 30 is settled is the home position of the paper feed cassette 7, and the position of the paper feed cassette 7 in the height direction is determined.

Therefore, the height of the paper feed cassette 7 is determined by the three points of the rollers 21 and 22 on the protrusion 34. In addition, similar to the projection 34 and the bearing portion 32, an operation reaction force is generated by the slope 29, which has an effect of reducing the impact when closing. In addition, there is no need for a dedicated rail or lock mechanism, so there is a simple and low cost effect.

(Second Embodiment)
Next explained is an image forming apparatus comprising a paper feed cassette according to the second embodiment of the invention. FIG. 12 shows an image forming apparatus provided with a sheet material feeding device according to the second embodiment.

  In the second embodiment, as in the first embodiment, an image reading device 103 is disposed above the image forming apparatus 101. Below the image forming unit 102 of the image forming apparatus 101, a sheet material feeding apparatus A1 including sheet feeding cassettes 107 and 108 is disposed. The shaded portion is the outer frame structure 150 of the image forming apparatus.

  The sheet material 116 in the paper feed cassette 107 is fed by paper feed rollers 124 and 125, and conveyed by the conveyance roller 106 through the conveyance path unit 113. Further, an image is formed by the image forming unit 102 and discharged outside the apparatus.

  The fulcrum shaft 132, which is the rotation center of the paper feed cassette 107, is located at the opposite end of the apparatus in the paper feed direction and at the front end, and has a two-sided cut shape that is integrated with the outer frame structure 150. Since the rotation center of the paper feed cassette 107 is integrated with the frame body, high accuracy can be maintained.

  Further, the hinge portion 120 of the paper feed cassette 107 that is rotatably fitted to the fulcrum shaft 132 has a C shape with a part opened, and when the paper feed cassette 107 is rotated 90 degrees, the paper feed cassette 107 is It is configured to be detached from the device.

  Further, rollers 121, 122, and 123 are arranged at the ends of the paper feed cassette 107, respectively, and the height position is determined at the home position as in the first embodiment, and an operation for opening the paper feed cassette 107 is performed. Then, the sheet feeding cassette 107 moves down the slope (not shown).

  Further, in conjunction with the rotation operation when the paper cassette 107 is pulled out, the transport path unit 113 constituting the transport unit moves in the direction of reference numeral 150 and moves to a position indicated by a dotted line that deviates from the rotation locus of the paper cassette 107. evacuate.

  Thus, by retracting the conveyance path unit 113 that interferes with the rotation trajectory of the paper feed cassette 107, the paper feed cassette 107 can be rotated without increasing the apparatus width. Therefore, a highly rigid frame configuration that makes the best use of the limited space and is not cut out by the rotation of the paper feed cassette 107 is possible.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.

1 is a top view of a sheet material feeding device according to a first embodiment of the present invention. 1 is a schematic front view of an image forming apparatus including a sheet material feeding device according to a first embodiment of the present invention. FIG. 3 is an enlarged detailed front view showing a part of the paper feed cassette unit according to the first embodiment of the present invention in a broken state. FIG. 3 is a top view showing a state of the paper feed cassette during the opening operation of the sheet material feeding device according to the first embodiment of the present invention. FIG. 3 is a top view showing a sheet feeding cassette in the vicinity of a maximum opening position of the sheet material feeding device according to the first embodiment of the present invention. FIG. 6 is a top view illustrating a state in which the paper feed cassette is detached at the maximum opening position in FIG. 5 according to the first embodiment of the present invention. It is a top view which shows the slide mechanism of the side guide of the sheet material feeding apparatus by the 1st Embodiment of this invention. It is explanatory drawing of the cam mechanism of the paper feed cassette rotation part by the 1st Embodiment of this invention. Explanatory drawing of the movement state of the cam surface of the paper feeding cassette rotation part in FIG. 8 by the 1st Embodiment of this invention. FIG. 9 is a diagram for explaining a state in which a cam surface of the sheet feeding cassette rotating unit of FIG. 8 is further moved according to the first embodiment of the present invention. It is a figure for demonstrating the roller of the paper feed cassette by the 1st Embodiment of this invention, and its guide part. FIG. 12A is a top view of a sheet material feeding device according to a second embodiment of the present invention, and FIG. 12B is a front view of a cross section of an image forming apparatus provided with the sheet material feeding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1a Outer frame frame 1b Main body frame 2 Image forming part 3 Image reading part 4 Discharge tray 5 Discharge roller 6 Conveyance roller 7, 8 Paper feed cassette 9 Auxiliary cover 12 Guide roller 13 Conveyance guide part 13a Pass 13b Pass 14 , 15 Rotating fulcrum shaft 16 Sheet material 17, 18 Side guide 19 Rear end guide 20 Guide fulcrum shaft 21, 22 Roller 21a, 22a Roller shaft 23, 31 Guide 24 Pick roller 25 Separating roller 26 Separating pad 27 Spring 29, 33 Slope 30 Kubomi 32 Bearing part 34 Projection 36 Pinion gear 37, 38 Rack gear 39 Guide cam surface

Claims (7)

A paper cassette for loading sheet materials;
A transport unit that transports the sheet material fed from the paper feed cassette,
A sheet material feeding device that rotatably supports the sheet feeding cassette with respect to the apparatus main body, and that can be pulled out with respect to the apparatus main body by rotating the sheet feeding cassette,
The sheet material feeding device, wherein the conveyance unit is configured to retract in conjunction with a rotation operation when the paper feeding cassette is pulled out.   The rotation center of the sheet feeding cassette is disposed in the vicinity of the sheet material center line parallel to the sheet material conveyance direction inside the apparatus body, and the rotation locus of the sheet feeding cassette is equal to or less than the width of the apparatus body. The sheet material feeding device according to claim 1. The sheet material feeding device according to claim 1 or 2, wherein when the paper feeding cassette is rotated and pulled out, the paper feeding cassette is positioned lower than a position accommodated in the apparatus main body. In order to move the paper feed cassette to a lower position when the paper feed cassette is pulled out, a guide cam is provided on one of the paper feed cassette or the apparatus main body, and a projection is provided on the other to be in sliding contact with the guide cam. The sheet material feeding device according to claim 3, wherein an operation reaction force is generated by the guide cam and the protrusion when the sheet feeding cassette is stored and operated. 5. The sheet feeding cassette is configured to be detachable from the apparatus main body, and the sheet feeding cassette is detachable when the sheet feeding cassette is rotated in the vicinity of a maximum rotation position. The sheet | seat material feeding apparatus of any one of these. The sheet material feeding device according to any one of claims 1 to 5, wherein a rotation center of the sheet feeding cassette is integrated with a frame body of the apparatus main body. The sheet material feeding device according to any one of claims 1 to 6,
An image forming apparatus comprising: an image forming unit that forms an image on a sheet material fed by the sheet material feeding device.

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