JP4155210B2 - Paper feeding device, large capacity paper feeding device, and image forming apparatus system - Google Patents

Description

  The present invention relates to a sheet feeding device capable of stacking sheets of different sizes, a large capacity sheet feeding device including the sheet feeding device, and an image forming apparatus system including the large capacity sheet feeding device.

  An image forming apparatus such as a copying machine or a printer is provided with a paper cassette for loading and feeding a predetermined amount of paper to form an image. When a large amount of paper is required, for example, 1000 sheets or more The large-capacity paper feeder (LCT) on which such a large amount of sheets can be loaded is connected to the side of the image forming apparatus, and paper is fed from the large-capacity paper feeder to the image forming apparatus.

  On the other hand, the large-capacity paper feeder can be loaded with different sized sheets, and is provided with a guide configured to be slidable so that different sized sheets can be set at regular positions. In the paper feeding direction, the leading edge of the paper abuts against a fixed member such as the inner wall of the large capacity paper feeding device, and the trailing edge is regulated by a trailing edge guide that is slidable in the feeding direction. Also, in the width direction orthogonal to the paper feeding direction, side guides are provided to regulate both side edges of the paper. When one side guide is slid, the other side guide is linked and reversed. The center position does not change even if the paper slides in the direction and has a different width. There is also a replaceable guide.

  In any case, the trailing edge guide and the side guide are variably provided in the horizontal direction with respect to the paper stacking unit for stacking the paper, and the position of the range from the lowermost surface to the uppermost surface of the paper is regulated.

  Here, among the plurality of stacked sheets, the uppermost sheet is configured to be held at a substantially constant height, and the uppermost sheet is fed by a feed roller and separated. The paper is separated into one sheet by a pair of paper rollers and fed by a pair of transport rollers. At this time, a rear end guide is provided in order to prevent the sheet from being retracted by the separating and separating roller pair and becoming unable to feed paper. The same applies to the influence of air assist for ensuring separation of the paper. As described above, the regulation of the trailing edge of the sheet by the trailing edge guide is important, and the trailing edge guide is configured so that its position can be changed according to the size of different sheets by a slide method or a replacement method.

As an example of the rear end guide for changing the position as described above, an invention has been disclosed in which an arm that expands and contracts is connected to the rear end guide so that paper of an arbitrary size can be set (see Patent Document 1).
JP 2002-46869 A

  The conventional trailing edge guide in the large-capacity paper feeder is located at the bottom of the large-capacity paper feeder so that the trailing edge of all the loaded paper can be regulated. It was long and formed so that it could be regulated. For this reason, the rear end guide has been enlarged in order to guarantee the strength. In addition, when the size is increased, precise movement becomes difficult and the cost is increased.

  The present invention has been made in view of such a problem. A sheet feeding device configured such that the rear end guide is short and small, a large-capacity sheet feeding device including the sheet feeding device, and the large-sized sheet feeding device. An object of the present invention is to provide an image forming apparatus system including a capacity sheet feeding device.

  The above object is achieved by the following means.

A paper stacking unit capable of stacking sheets of different sizes, a paper feeding unit that feeds sheets one sheet at a time on the top surface of the paper stacked on the paper stacking unit, and an opening / closing operation above the paper stacking unit in the sheet feeding apparatus having a lid, a to and slide back and forth relative to the sheet feed direction, wherein the opening and closing an end guide after you regulate the rear end with respect to the paper feeding direction of the sheet located on a top surface A paper feeder provided on a lid.

According to the paper feeding device of the first aspect, since the rear end guide for restricting the rear end portion with respect to the paper feeding direction of the paper located on the uppermost surface is provided on the opening / closing lid located above the paper stacking portion, The length of the end guide is short and small, and the rear end portion of the paper to be fed can be stably regulated.

  According to the paper feeding device of the second aspect, even when two paper feeding units are provided, the effect equivalent to that of the first aspect is obtained.

According to the paper feeding device of the third aspect , when the trailing edge guide that is driven and moved contacts the trailing edge of the sheet, it automatically stops.

According to the sheet feeding device described in claims 4 and 5 , the length (size) of the sheet can be detected and output to the image forming apparatus.

According to the large-capacity paper feeding device described in claim 6 , the effects of claims 1-5 are provided.

The image forming apparatus system according to the seventh aspect has the effects of the first to fifth aspects.

  Hereinafter, embodiments of the paper feeding device of the present invention will be described with reference to the drawings.

  First, a configuration of an image forming apparatus system including an image forming apparatus and a large-capacity sheet feeding apparatus including a sheet feeding apparatus will be described with reference to FIG.

  The image forming apparatus A is called a tandem type color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, a belt-like intermediate transfer member 6, a paper feeding device 20, a fixing device 30, and the like. Consists of.

  On the upper part of the image forming apparatus A, an image reading apparatus B is installed. The document placed on the document table is scanned and exposed by the optical system of the document image scanning exposure apparatus of the image reading apparatus B, and read by the line image sensor. The analog signal photoelectrically converted by the line image sensor is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit, and then input to the exposure means 3Y, 3M, 3C, 3K. The

  The image forming unit 10Y that forms a yellow (Y) image includes a charging unit 2Y, an exposure unit 3Y, a developing device 4Y, and a cleaning unit 5Y disposed around a photosensitive drum 1Y as an image carrier. The image forming unit 10M that forms a magenta (M) color image includes a photosensitive drum 1M as an image carrier, a charging unit 2M, an exposure unit 3M, a developing device 4M, and a cleaning unit 5M. An image forming unit 10C for forming a cyan (C) color image includes a photosensitive drum 1C as an image carrier, a charging unit 2C, an exposure unit 3C, a developing device 4C, and a cleaning unit 5C. The image forming unit 10K that forms a black (K) image includes a photosensitive drum 1K as an image carrier, a charging unit 2K, an exposure unit 3K, a developing device 4K, and a cleaning unit 5K. The charging unit 2Y and the exposure unit 3Y, the charging unit 2M and the exposure unit 3M, the charging unit 2C and the exposure unit 3C, and the charging unit 2K and the exposure unit 3K constitute a latent image forming unit.

  The developing devices 4Y, 4M, 4C, and 4K include a two-component developer including yellow (Y), magenta (M), cyan (C), and black (K) small particle size toners and a carrier.

  The intermediate transfer body 6 is wound around a plurality of rollers and is rotatably supported.

  The respective color images formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially transferred (primary transfer) by the primary transfer units 7Y, 7M, 7C, and 7K onto the rotating intermediate transfer body 6, and a color image is formed. Synthesized.

  The paper S accommodated in the paper feeding cassette 21A of the paper feeding device 20 is fed by the paper feeding means 22A and conveyed to the transfer roller 9 through the paper feeding rollers 23, 24, 25, 26, the registration rollers 27, and the like. Then, the color image is transferred (secondary transfer) onto the paper S.

  Note that the three-stage sheet feeding cassettes 21A arranged vertically in the vertical direction below the image forming apparatus A have substantially the same configuration, and thus are given the same reference numerals. Further, the three-stage sheet feeding means 22A has the same configuration and is therefore given the same reference numeral.

  Further, the sheet feeding device 21 including the sheet feeding cassette 21A and the sheet feeding unit 22A is referred to as a sheet feeding device 20.

  The sheet S on which the color image is transferred is sandwiched between the heating roller 30A and the pressure roller 30B in the fixing device 30, and heated and applied. As a result, the toner image on the paper S is fixed and fixed on the paper S, and is sandwiched between the paper discharge rollers 28 and placed on the paper discharge tray 29 outside the apparatus.

  On the other hand, after the color image is transferred onto the paper S by the transfer roller 9, the residual toner is removed by the cleaning unit 8 from the intermediate transfer body 6 that has separated the curvature of the paper S.

  In the case of reversely discharging the fixed sheet S, the sheet S passes through the lower conveyance path of the branch plate 28A disposed between the fixing device 30 and the sheet discharge roller 28, and the lower conveyance path r1. Then, the sheet is conveyed in the reverse direction, passes through the conveying path r2 on the left side of the branch plate 28A, and is discharged out of the apparatus by the paper discharge roller 28.

  When copying on both sides of the sheet S, after fixing the image formed on the first surface of the sheet S, the sheet S is introduced into the transport path r1 and further into the transport path r3, then transported in reverse, and transported path r4. Then, the sheet is detoured upward and conveyed by the paper feed roller 26. In the same manner as described above, the sheet S is formed with an image of each color on the second surface which is the back surface of the first surface, heated and fixed by the fixing device 30, and discharged to the outside by the discharge roller 28.

  The image forming apparatus A is provided with a manual sheet feeding device C. The paper S accommodated in the manual paper feed tray 21B of the manual paper feed device C is fed by the paper feed means 22B, sent to the transfer roller 9 through the paper feed rollers 25 and 26 and the registration roller 27, and Similarly, an image is formed.

  The image forming apparatus A described above is an image forming apparatus that forms a color image, but may be an image forming apparatus that forms a monochrome image.

  On the right side in the figure of the image forming apparatus A, a large capacity sheet feeder LT for feeding a large amount of sheets of, for example, 1000 sheets or more is connected. Based on the large-capacity paper feeder LT, the paper feeder according to the present invention will be described.

  The large-capacity paper feeding device LT includes a main body 40 that stores the paper S, and an opening / closing lid 50 that is configured to be openable and closable with respect to the main body 40 when the paper S is stored. The opening / closing lid 50 has a hinge (not shown) substantially parallel to the feeding direction of the paper S, for example, and opens / closes with respect to the main body 40. The main body 40 is provided with a paper stacking portion 41, a paper feeding portion including a feed roller 42, a separation roller pair 43, and a transport roller pair 44, and a rear end guide 51 is provided on the opening / closing lid 50.

  The sheet S is stacked on the sheet stacking unit 41. When the opening / closing lid 50 is opened, the sheet stacking unit 41 is positioned below. When the sheet S is stacked and the opening / closing lid 50 is closed, the sheet S is not illustrated. Driven by the motor and ascend. Then, when a sensor (not shown) detects the paper S positioned on the uppermost surface, the ascent of the paper stacking unit 41 is stopped, and the height of the paper S positioned on the uppermost surface becomes substantially constant.

  When a paper feed signal for feeding paper from the large-capacity paper feeder LT is output from the image forming apparatus A to the large-capacity paper feeder LT, the feed roller 42 pressed against the paper S located on the uppermost surface rotates. The sheet is separated into one sheet by the separating roller pair 43 and fed into the image forming apparatus A by the conveying roller pair 44.

  The large-capacity paper feeder LT can store paper of different sizes. In the paper feeding direction of the paper S, the leading edge of the paper S abuts against a fixing member in the main body 40, and the trailing edge is regulated by the trailing edge guide 51 according to the present invention. The rear end guide 51 will be described later in detail. Further, in the width direction orthogonal to the paper feeding direction of the paper S, side guides (not shown) that restrict both side ends of the paper S are provided in the main body 40, and when one side guide is moved, the other side guide is moved. The side guide is interlocked and moved in the opposite direction, so that the center position does not change even for sheets of different widths. In addition, what is necessary is just to use this well-known and common side guide.

  Next, the rear end guide 51 will be described with reference to FIG. FIG. 2 is a perspective view of the rear end guide 51 and the like.

  A guide shaft 52 penetrates the rear end guide 51 and is screwed with a screw shaft 53 provided with a screw on the outer periphery, and both ends of the guide shaft 52 and the screw shaft 53 are suspended from the opening / closing lid 50. 54, 55. Further, a motor 56 (driving means) directly connected to the screw shaft 53 is fixed to the support plate 55. Accordingly, when the motor 56 is rotated, the screw shaft 53 is also rotated, and the rear end guide 51 is driven by the screw shaft 53 and guided by the guide shaft 52 to move in the left-right direction in FIG.

  Here, when the opening / closing lid 50 is opened, the rear end guide 51 stands by at the initial position (51) by detection of a sensor (not shown). Thereafter, when the sheet S is stacked on the sheet stacking unit 41 and the opening / closing lid 50 is closed, the sheet stacking unit 41 is driven and raised by a motor (not shown). Then, when the sensor (not shown) detects the sheet S positioned on the uppermost surface, the ascent of the sheet stacking unit 41 is stopped. Subsequently, the motor 56 rotates, and the trailing edge guide 51 moves to the left from the initial position (51) and comes into contact with the right edge of the paper S, that is, the trailing edge. As a result, the movement of the rear end guide 51 is prevented, and an overcurrent flows in the circuit of the motor 56. When a microcomputer (not shown) or the like (control means) detects that an overcurrent has flowed for a predetermined time, the microcomputer turns off the circuit of the motor 56 and stops the rotation of the motor 56.

  In this way, the trailing edge guide 51 stays at a fixed position, and even if the lower sheets S are successively conveyed from the uppermost sheet S and the lower sheets S rise one after another, the rear end portion of the sheet S that is always conveyed. Continue to regulate. Therefore, the rear end guide 51 can be shorter in the vertical direction than the conventional rear end guide. Further, the conventional art also has a short distance from the abutting portion 53 a that abuts on the sheet S positioned on the uppermost surface of the rear end guide 51 and the guide shaft 52 and the screw shaft 53 that are the support portions for supporting the rear end guide 51. Compared with the prior art in which the trailing edge guide is erected longer than the lower part of the main body, the trailing edge of the sheet S can be regulated very stably and reliably.

  Note that the screw shaft is not necessarily used as a mechanism for moving the rear end guide 51, and may be moved by a rack and pinion, a belt, a wire, or the like.

  In addition, various sizes of sheets S can be stacked on the sheet stacking unit 41. Accordingly, the amount of movement until the trailing edge guide 51 moves to the left from the initial position (51) and contacts the trailing edge of the sheet S differs depending on the size of the sheet S. Since the movement amount of the trailing edge guide 51 is different in this way, the movement time is different, so the size of the paper S can be detected from the movement time, and this information can be output to the image forming apparatus A. it can.

  For example, assuming that sheets S of sizes A3, B4, A4R, B5R, A4, A5R, B5, and B6R can be stacked, the length of the sheet S in the sheet feeding direction is as shown in Table 1.

  Accordingly, if the amount of movement until the trailing edge guide 51 moves from the initial position (51) and contacts the trailing edge of the A3 sheet S is L, the trailing edge guide 51 continues to contact the trailing edge of another size sheet S. The amount of movement is as shown in Table 1. Since the movement speed of the trailing edge guide 51 can be made substantially constant, the movement time of the trailing edge guide 51 with respect to each size of the sheet S is obtained in advance, and the relationship between the movement time of the trailing edge guide 51 and the sheet size is determined. If the memory is stored as a table in a microcomputer or the like (detection means), the size of the stacked sheets S can be detected, and this information can be output to the image forming apparatus A.

  Further, in order to detect the size of the paper S, a plurality of photo sensors (detecting units) may be arranged.

  An example of this is shown in FIG. 3. Photosensors 61 are arranged at the respective stop positions of the rear end guide 51 that stops corresponding to the size of the paper S. If the rear end guide 51 stops at the position (E), the photo sensor 61e detects this and detects that the microcomputer or the like (detection means) is, for example, A4 size. If it stops at the position D), this is detected by the photo sensor 61d and the microcomputer or the like detects that the size is, for example, B5R, and if the rear end guide 51 stops at the position (C), this is detected. The photo sensor 61c detects that the microcomputer is A4R size, for example.

  If the photosensor is arranged in this way, the size of the paper S can be detected even when the rear end guide 51 is moved manually without being electrically moved.

  Further, as shown in FIG. 4, the photo sensor 62 may be arranged in the middle of each stop position of the rear end guide 51. For example, if the usable paper sizes are A3, B4, A4R, B5R, A4,..., Between the initial position and A3 size, between A3 size and B4 size, between B4 size and A4R size, A4R. Photosensors are arranged between the size and the B5R size, between the B5R size and the A4 size, and the like. If the rear end guide 51 stops at the position (E) and is A4 size, the five sensors including the photo sensors 62c, 62d, and 62e are moved until the rear end guide 51 moves to the position (E). Since the photo sensor 62 detects, the microcomputer S or the like (detection means) detects that the paper S when the rear end guide 51 stops at the position (E) is the fifth paper S and is A4 size. it can.

  Furthermore, instead of the large capacity sheet feeder LT having the rear end guide 51 described above, a large capacity sheet feeder LT1 as shown in FIG. 5 may be used.

  In the large-capacity paper feeding device LT1 shown in FIG. 5, any non-long paper S such as A4 size or B5 size can be stacked on the left and right of the paper stacking unit 141. Then, the sheets S stacked on the left side are fed into the image forming apparatus A by the feed roller 142, the separation roller pair 143, and the transport roller pair 144 (first paper feed unit), as in the large-capacity paper feeder LT described above. Paper is fed to On the other hand, the sheets S stacked on the left are conveyed to the right in the reverse direction by the feed roller 145, the separation roller pair 146, and the conveyance roller pair 147, the conveyance direction is reversed by the reverse roller pair 148, and further conveyed. It is conveyed by the roller pairs 149, 156, 157, 158 (the delivery roller 145 to the conveyance roller pair 158 are the second paper feed unit) and conveyed to the conveyance roller pair 144.

  Similarly to the large-capacity paper feeder LT, the lid 150 opens and closes with respect to the main body 140. The lid 150 has two rear end guides on the guide shaft 153 supported by the support plates 154 and 155, that is, The first rear end guide 151 and the second rear end guide 152 are slidably fitted. The first rear end guide 151 regulates the rear end portion (right end portion) of the sheets S stacked leftward, and the second rear end guide 152 is the rear end portion of the sheets S stacked rightward ( (Left end) is regulated.

  Here, if the loading amount of the sheets S stacked on the left and right is the same, the left and right sheets S are alternately conveyed, and if the loading amount of the sheets S stacked on the left and right is different, the sheet S having the larger loading amount is loaded. If the stacking amounts of the sheets S that have been transported first and left and right are the same, the left and right sheets S are transported alternately.

  In addition, the first rear end guide 151 and the second rear end guide 152 can be moved electrically or manually according to the size of the paper S, and the size of the paper S can be detected similarly. it can.

  In the case of a long and large sheet S such as B4 or A3, the sheet S can be stacked only on the left side, so that only the rear end guide 151 is used and the rear end guide 152 is retracted to the right.

1 is a configuration diagram of an image forming apparatus system including an image forming apparatus and a large-capacity sheet feeding apparatus including a sheet feeding apparatus. It is a perspective view, such as a rear end guide. It is a perspective view of the photosensor which detects a rear end guide. It is another perspective view of the photosensor which detects a back end guide. 1 is a configuration diagram of an image forming apparatus system including an image forming apparatus and a large-capacity sheet feeding device including a sheet feeding device including two sheet feeding units.

Explanation of symbols

A Image forming apparatus LT Large-capacity paper feeder S Paper 40 Main body 41 Paper stacking section 50 Opening / closing lid 51 Rear end guide 56 Motor 61, 62 Photo sensor 151 First rear end guide 152 Second rear end guide

Claims (7)

A paper stacking unit that can load paper of different sizes;
A paper feeding unit that feeds the paper located on the top surface of the paper stacked on the paper stacking unit one by one;
An open / close lid that opens and closes above the paper stacking unit;
In a paper feeder provided with
Slides back and forth relative to the sheet feeding direction, the sheet feeding apparatus, characterized in that said rear end guide for restricting the end after against the paper feed direction of the paper that is located on a top surface provided on the lid . The paper feeding unit feeds the first paper feeding unit in a direction opposite to the first paper feeding unit, then reverses the paper, and feeds the paper in the paper feeding direction by the first paper feeding unit. And a second paper feed unit
The trailing edge guide includes a first trailing edge guide that regulates a trailing edge of a sheet fed by the first sheet feeding unit, and a trailing edge of a sheet fed by the second sheet feeding unit. The sheet feeding device according to claim 1, further comprising a second rear end guide for regulating the portion. Driving means for moving back and forth relative to the sheet feed direction to drive the rear guide,
Control means for detecting the current flowing through the drive means and controlling the drive of the drive means;
With
The control means includes
Wherein the drive of the driving means controlled to move in the sheet feed direction the rear guide from a predetermined position, after it is detected that an overcurrent flows at a given time the drive means to stop the drive of the drive means The sheet feeding device according to claim 1, wherein the sheet feeding device is provided. A table for storing a relationship between a length of the paper in the paper feeding direction and a movement time of the trailing edge guide from the predetermined position;
Detecting means for measuring a moving time of moving the trailing edge guide from the predetermined position and detecting a length of the paper in the paper feeding direction based on the table;
The sheet feeding device according to claim 3, further comprising: A plurality of detection units for detecting the position of the rear end guide ;
Detection means for detecting a paper feeding direction of the length of the sheet by the detection unit,
The sheet feeding device according to any one of claims 1 to 3, further comprising: A large-capacity paper feeding device comprising the paper feeding device according to claim 1 . 7. An image forming apparatus system comprising: the large capacity sheet feeding device according to claim 6 ; and an image forming apparatus that forms an image of a sheet fed from the large capacity sheet feeding apparatus .

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