JP2010126345A - Paper delivery device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper delivery device and an image forming device ensuring loading capacity and alignability of sheets and achieving excellent sheet taking-out performance even if a plurality of sheets is loaded on a paper ejection tray. <P>SOLUTION: This paper delivery device includes: the paper ejection tray 15 loading the sheet 23 delivered from a delivery port 32; a sidewall surrounding the sheet loading surface 35 of the paper ejection tray 15; an auxiliary member 17 provided to a part of the sheet loading surface 35 of the paper ejection tray 15; and a drive source driving the auxiliary member 17. The auxiliary member 17 is freely vertically moved. When the auxiliary member 17 is upwardly moved by being driven by the drive source, only some of the peripheries of the sheets loaded on the sheet loading surface 35 are lifted higher than the sheet loading surface 35 of the paper ejection tray 15, thereby a clearance for inserting fingers when taking out the sheet is formed between the sheet loading surface 35 of the paper ejection tray and the lowermost sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a paper discharge device for stacking sheets (paper) on a paper discharge tray and an image forming apparatus including the paper discharge device.

  2. Description of the Related Art Generally, a sheet discharge tray of an image forming apparatus is configured by arranging a stacking surface of sheets discharged from a discharge port, a wall around the sheet stacking surface, or a movable regulating member. This is for orderly aligning the stacked sheets (paper). Therefore, in order to stack sheets on a plurality of sheet discharge trays, it is necessary to increase the side wall height around the sheet stacking surface. In recent years, in image forming apparatuses, there has been a great demand for printing on various recording media having different thicknesses and sizes, such as envelopes and postcards, as well as ordinary cut sheets, and various types of sheets that are arranged in an orderly manner. Have been proposed.

  For example, as disclosed in Patent Document 1 and Patent Document 2, an apparatus that elastically supports the paper discharge tray so as to gradually descend according to the weight of the sheets stacked thereon is known.

Japanese Patent No. 3233654 Japanese Utility Model Publication No. 56-10751

  However, the techniques of Patent Documents 1 and 2 are effective in terms of sheet alignment and securing the stacking amount, but when considering the take-out property of the sheets stacked on the discharge tray, as described above, When multiple sheets are stacked on the output tray, the side wall height around the sheet stacking surface increases, so there is little space for inserting hands when taking out the sheets, and it is not convenient for the user. There was no.

  Accordingly, the present invention provides a paper discharge device and an image forming apparatus that ensure the sheet stacking capacity and alignment even when a plurality of sheets are stacked on a paper discharge tray, and that have good sheet pick-up performance. .

  The present invention relates to a discharge tray for stacking sheets discharged from a discharge port, a side wall surrounding a sheet stacking surface of the discharge tray, an auxiliary member provided on a part of the sheet stacking surface of the discharge tray, and an auxiliary member The auxiliary member is movable up and down, and the auxiliary member moves upward by driving the drive source, so that only a part of the peripheral edge of the sheet placed on the sheet stacking surface is discharged. The sheet tray is lifted above the sheet stacking surface of the paper tray.

  According to the present invention, the sheet stacking capacity and alignment are ensured by the side wall surrounding the sheet stacking surface, and only a part of the peripheral edge of the lowermost sheet on which the auxiliary member is stacked is lifted above the sheet stacking surface. Thus, when a sheet is taken out, a gap for inserting a finger can be formed between the sheet stacking surface of the paper discharge tray and the lowermost sheet.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below with reference to the accompanying drawings. First, the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of the image forming apparatus according to the first embodiment, and is a longitudinal sectional view showing a state where the auxiliary member lifts the sheet. FIG. 2 shows the image forming apparatus according to the first embodiment. FIG. 3 is a longitudinal sectional view showing a schematic configuration before the auxiliary member lifts the sheet, and FIG. 3 is a sectional view showing the configuration of the control block while cutting the image forming apparatus shown in FIG. 4 at the BB position. FIG. 4 is a perspective view of the image forming apparatus according to the first embodiment. In FIG. 4, the sheet is omitted. In each figure, reference numeral 23 denotes a sheet after image formation, and reference numeral 23a denotes a sheet before image formation.

  As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment is a printer, and an image forming unit 2 that forms an image on a sheet (paper) 23 and a sheet on which the image is formed are discharged from a discharge port 32. Thus, a sheet discharge unit 30 (sheet discharge device) for stacking sheets is provided.

  As shown in FIG. 3, the image forming apparatus 1 is connected to a personal computer (PC) 31 through a communication line. When the image forming apparatus 1 receives an output signal together with a setting signal such as the number of prints from the personal computer 31, the image forming apparatus 1. The controller 33 forms an image on a predetermined number of sheets 23 a in response to the output signal, and then sequentially discharges the sheets 23 after the image formation to the paper discharge unit 30.

  As shown in FIGS. 1 and 4, the paper discharge unit (paper discharge device) 30 includes a paper discharge tray 15 on which sheets discharged from the discharge port 32 are stacked, and a side wall that surrounds the sheet stacking surface 35 of the paper discharge tray 15. 29, an auxiliary member 17 provided on a part of the sheet stacking surface 35 of the paper discharge tray 15, and a drive source 37 (see FIG. 3) for driving the auxiliary member 17.

  A pair of paper discharge rollers 14 is provided at the discharge port 32, and the sheet on which the image is formed by the image forming unit 2 is discharged to the paper discharge tray 15. A sheet discharge detector 34 is provided at the sheet discharge port 32, and the detection unit 34 counts the number of discharged sheets by sending a detection signal to the control unit 33 shown in FIG. It is supposed to be.

  The sheet stacking surface 35 of the sheet discharge tray 15 is inclined with the downstream side in the sheet discharge direction from the discharge port 32 (the side away from the discharge port 32) upward.

  The auxiliary member 17 supports only a part of the peripheral edge of the lowermost sheet placed on the sheet stacking surface 35 of the paper discharge tray 15 and lifts it above the sheet stacking surface 35 of the paper discharge tray 15. In the present embodiment, as shown in FIG. 4, the sheet is provided on one end side (right side) in the left-right direction orthogonal to the sheet discharge direction, and the sheets stacked on the sheet stacking surface 35 of the sheet discharge tray 15. The left and right end portions perpendicular to the discharge direction are lifted.

  The auxiliary member 17 is a plate-like member that is rotatably provided. As shown in FIG. 1, the auxiliary member 17 has a rotation fulcrum 16 on the downstream side in the sheet discharge direction, and a tip on the upstream side in the sheet discharge direction of the rotation fulcrum 16. A portion 17a is provided, and the distal end portion 17a moves up and down as the auxiliary member 17 rotates about the rotation fulcrum 16.

  A cam 18 that contacts the lower surface of the auxiliary member 17 is provided under the auxiliary member 17. A rotating shaft 19 of a motor, for example, is connected to the rotating shaft 19 of the cam 18 as a drive source 37 (see FIG. 3). The auxiliary member 17 is swung up and down by rotating around the rotation shaft 19 by driving the drive source.

  A side wall 29 surrounding the sheet stacking surface 35 is provided in the paper discharge tray 15. As shown in FIG. 4, the side wall 29 is composed of left and right side walls 29a and 29b, a front wall 29d, and a rear wall 29c, and the sheet 23a discharged from the discharge port 32 is regulated in the left and right front and back and stacked. The sheet edges are aligned. In this embodiment, the rear wall 29c is a fixed wall. However, a long sheet can be accommodated by making it movable in the paper discharge direction. By providing the side wall 29 as described above, the alignment of the sheets can be ensured.

  As shown in FIG. 3, the left wall 29 a is provided with a sheet detector 28 that detects the presence or absence of a sheet on the paper discharge tray 15, and the sheet detector 28 detects the presence or absence of a sheet 23 on the paper discharge tray 15. Then, a detection signal is sent to the control unit 33, and the control unit 33 controls to drive the drive source 37 only when a detection signal indicating the presence of a sheet is received from the sheet detector 28.

  Here, the configuration of the image forming unit 2 will be described with reference to FIGS. 1 and 2. The image forming unit 2 includes a plurality of drum-shaped photoconductors 3a, 3b, 3c, and 3d configured as image carriers, and toner images of different colors are formed on the respective photoconductors. The In the illustrated example, a yellow toner image, a cyan toner image, a magenta toner image, and a black toner image are formed on the surfaces of the photoreceptors 3a to 3d, respectively. The photoconductors 3a to 3d are arranged in parallel with each other at a predetermined interval, and an intermediate transfer belt 4 configured as an intermediate transfer body is arranged facing the lower part of the photoconductors 3a to 3d. A drum may be used as the intermediate transfer member, but in the illustrated example, an endless belt that is wound around and driven by a plurality of support rollers 5 and 6 is used. Around each of the photoreceptors 3a to 3d, there are charging devices 7a to 7d for charging the surface of the photoreceptor, an optical scanning device (LSU) 8 for irradiating the photoreceptor surface with laser light with image information, and the photoreceptor 3a by exposure. Developing devices 9a to 9d for visualizing the electrostatic latent images formed on the surfaces 3d to 3d, and transfer devices 10a to 10d arranged to face the photoconductors 3a to 3d via the intermediate transfer belt 4. ing.

  Next, the operation of the image forming unit 2 will be described. When image formation is started by a print start signal from the PC 31 (see FIG. 3), the photosensitive member 3a is rotated by a driving source not shown here, and at this time, the surface of the photosensitive member 3a by the charging device 7a. Is charged to a predetermined polarity. Next, the charged surface is irradiated with laser light based on image information from the optical scanning device 8, thereby forming an electrostatic latent image on the photoreceptor 3 a. The electrostatic latent image formed on the surface of the photoreceptor 3a is visualized as a toner image by the developing device 9a, and the toner image is transferred onto the intermediate transfer belt 4 by the transfer device 10a. At the time of color image formation, the above-described image forming operation is performed on all the photoconductors 3a to 3d, and thereby the yellow toner image, cyan toner image, magenta toner image, and black toner image respectively formed on the photoconductors 3a to 3d. Are sequentially superimposed and transferred onto the intermediate transfer belt 4. Further, the image forming apparatus is provided with a secondary transfer roller 12 facing the support roller 6 with the intermediate transfer belt 4 interposed therebetween. On the other hand, sheets 23 are stacked on a sheet feeding cassette 21 disposed at the lower portion of the image forming unit 2 and a sheet feeding roller 22 for feeding the stacked sheets 23a is provided. The sheet 23a fed from the paper feed cassette 21 is sent out toward the registration roller 11 and abuts against the registration roller 11 whose leading end is stopped. Thus, after the sheet 23a is aligned, the registration roller 11 causes the color toner image formed on the intermediate transfer belt 4 to coincide with the leading end of the sheet 23a at the secondary transfer portion provided with the secondary transfer roller 12. The rotation is resumed at a proper timing, and the sheet 23a is sent out toward the secondary transfer portion. The sheet 23 a on which the unfixed toner image is transferred in the secondary transfer unit is sent to the fixing unit 13, and after the unfixed toner image is fixed on the sheet 23 a, the sheet 23 on which the image is formed by the paper discharge roller 14. Is discharged in the direction of arrow A in the figure, and is discharged to the paper discharge tray 15 from the paper discharge port 32 provided at the top of the image forming apparatus 1.

  Next, the operation of the paper discharge unit (paper discharge device) 30 will be described. As shown in FIG. 2, the image-formed sheets 23 are sequentially discharged and stacked on the paper discharge tray 15, and a predetermined number of sheets, for example, 20 sheets set by the PC shown in FIG. When a detection signal indicating the presence of a sheet is sent from the device 28 to the control unit 33, the control unit 33 drives the drive source 37, the cam 18 rotates in the direction of arrow B in FIG. 1, and the auxiliary member 17 is moved to FIG. It raises from the position shown to the position shown in FIG.1 and FIG.3.

  As a result, as shown in FIG. 1, only the rear end (the end on the front wall 29d side) of the sheets 23 stacked on the sheet discharge tray 15 is lifted. That is, as shown in FIG. 3, a part of the sheet 23 stacked on the sheet discharge tray 15 is lifted so as to create a gap σ between the sheet stacking surface of the sheet discharge tray 15 and the sheet 23. The remaining portion of the sheet 23 is in a state in which the sheet 23 is stacked without forming a gap between the other portion of the sheet 23 and the sheet stacking surface 35 of the sheet discharge tray 15. Thus, by lifting the sheet 23 and creating a gap between only a part of the sheet 23 and the paper discharge tray, it is possible to secure a space where a finger can be inserted. Therefore, the user can easily take out the sheets 23 stacked on the paper discharge tray 15 by inserting a finger into the gap.

  According to the present embodiment, the side wall 29 surrounding the sheet stacking surface 35 ensures the stacking capacity and alignment of the sheets 23, and only a part of the peripheral edge of the sheet 23 on which the auxiliary member 17 is stacked is the sheet stacking surface 35. When the stacked sheet 23 is taken out, the sheet 23 can be easily taken out by placing a finger in the gap between the sheet stacking surface 35 of the paper discharge tray 15 and the lowermost sheet. .

  Further, as shown in FIG. 3, the auxiliary member 17 lifts the rear end portion of the sheet 23 so as to create a gap σ between the sheet stacking surface of the sheet discharge tray 15 and the sheet 23 only at the left and right sides. Since the portion is not lifted, there is no space between the sheet stacking surface 35 of the paper discharge tray 15 and the load on the cam 18 and the drive source 37 can be minimized.

  The detection sensor 28 detects the presence / absence of the sheet 23 on the paper discharge tray 15. If there is no sheet 23 on the paper discharge tray 15, control is performed so that the cam 18 and the auxiliary member 17 are not operated. Energy saving can be achieved.

  In this embodiment, the number of discharged sheets 23 is counted, and the auxiliary member 17 is raised after discharging the number of sheets set by the PC. Therefore, after the discharge of a predetermined number of sheets 23 is completed, The sheet 23 can be easily removed.

  Other embodiments of the present invention will be described below. In the embodiments described below, the same reference numerals are given to the same portions as the above-described embodiments, and the details of the portions are described. The description will be omitted, and the following description will mainly describe differences from the embodiment described above.

  A second embodiment will be described with reference to FIGS. 5 and 6 are enlarged cross-sectional views showing the auxiliary member 17 and its surroundings. FIG. 5 shows the auxiliary member 17 in the raised position, and FIG. 6 shows the auxiliary member 17 in the lowered position. ing.

  The second embodiment is different from the above-described embodiment in that a retraction mechanism 39 that retreats the auxiliary member 17 when a downward load on the auxiliary member 17 becomes larger than a predetermined value is provided. The retraction mechanism 39 includes a support member 24 and a spring 25, and both ends of the rotating shaft 19 of the cam 18 are pivotally supported on the support member 24, and a spring 25 is provided below the support member 24. The lower end of the spring 25 is fixed in the housing of the image forming apparatus 1. The interlocking gear 26 driven by the drive source 37 is fixed to the casing of the image forming apparatus, and the driven gear 26a fixed to the rotating shaft 19 of the cam 18 is detachably connected to the interlocking gear 26.

  Note that the gear of the motor as the drive source 37 is connected to the gear of the paper discharge roller 41 provided at the sheet discharge port 32 via the chain 40a, and is connected to the interlocking gear 26 via the chain 40b. In addition, a drive source (motor) 37 for the discharge roller is commonly used as a drive source for the auxiliary member 17. Thereby, the number of parts can be reduced.

  In the second embodiment, for example, the number of sheets 23 stacked on the sheet discharge tray 15 is too large, and the auxiliary member 17 and the cam 18 via the auxiliary member 17 exert an external force of a predetermined level or more from above. When (weight) F works, as shown in FIG. 6, the cam 18 descends together with the support member 24, so that the driven gear 26 a disposed on the rotating shaft 19 and the interlocking gear 26 are disconnected. Thereby, even when the number of stacked sheets is too large and an excessive weight is applied, the cam 18 and the auxiliary member 17 can be prevented from being damaged. In the second embodiment, the drive source 37 is provided exclusively for driving the cam 18 in addition to the drive source for the paper discharge roller, and the drive source 37 for the cam 18 is also supported by the support member 24. good.

  Next, a third embodiment of the present invention will be described with reference to FIG. 7 is a cross-sectional view of the image forming apparatus according to the third embodiment cut at the same position as the BB position of image formation shown in FIG. 4, and corresponds to FIG. 3 of the first embodiment. It is a thing.

  In the third embodiment, the rotation fulcrum 16 of the auxiliary member 17 is provided on the right side wall 29d, and the tip 17a of the auxiliary member 17 is provided to extend toward the left side wall 29a of the paper discharge tray. The cam 18 provided below the auxiliary member 17 is configured to rotate in the direction of arrow C in FIG.

  According to the third embodiment, as the cam 18 rotates, the auxiliary member 17 removes only a part of the right end of the sheet 23 stacked on the sheet discharge tray 15 from the sheet stacking surface 35 of the sheet discharge tray 15. And the sheet 23 are lifted so as to create a gap G. In the sheet 23, no gap is formed between the sheet 23 and the sheet stacking surface 35 of the sheet discharge tray 15 at a portion other than the lifted portion. By lifting the sheet 23 and creating a gap between the sheet 23 and the sheet stacking surface 35 in this way, it is possible to secure a space where a finger can be inserted, and the same effect as in the first embodiment can be obtained. Can do.

  Further, according to the third embodiment, since the rotation fulcrum 16 of the auxiliary member 17 is provided on the right side wall 29b, a finger is sandwiched between the auxiliary member 17 and the cam 18 when the sheet is taken out from the right side. Can be prevented.

  A fourth embodiment will be described with reference to FIGS. FIG. 8 is a perspective view of the image forming apparatus 1 according to the fourth embodiment, and FIG. 9 is a cross-sectional view taken along line AA shown in FIG. In FIG. 8, the sheet 23 is omitted. As shown in FIG. 8, in the fourth embodiment, a recess 27 in which a part of the upper surface of the right side wall 29b is recessed is formed, and when the auxiliary member moves upward, the upper surface 17 of the auxiliary member. Is moved higher than the upper surface 27 a of the recess 27. Other points are substantially the same as those of the first embodiment described above.

  In the fourth embodiment, as is clear from FIG. 8, when the auxiliary member 17 is lifted, the seat portion lifted by the auxiliary member 17 has a recessed portion 27 whose height of the lower surface of the lowermost sheet is higher. 9, the gap h shown in FIG. 9 is formed, so that a space for inserting a finger can be secured. Therefore, when the concave portion 27 is provided and the hand is taken out from the direction of the arrow D in the drawing and the sheet is taken out, the taking-out property of the sheet is further improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  For example, the paper discharge unit (paper discharge device) 30 may be provided in a post-processing device such as a sheet punching process or a folding process.

  The auxiliary member 17 is not limited to one that rotates one end and moves the tip up and down, but may also move the entire auxiliary member 17 up and down.

  The retraction mechanism 39 is not limited to the spring 25, and may be one that detects the weight of the auxiliary member 17 and lowers the holding member 24 by driving a motor or the like.

  In the fourth embodiment shown in FIGS. 8 and 9, the recess 27 is not limited to being provided on the right side wall 29b, but may be provided on other side walls such as the left side wall 29a and the rear side wall 29c.

FIG. 2 is a longitudinal sectional view illustrating a schematic configuration of the image forming apparatus according to the first embodiment and showing a state where an auxiliary member lifts a sheet. FIG. 2 is a longitudinal sectional view illustrating a schematic configuration of the image forming apparatus according to the first embodiment and illustrating a state before the auxiliary member lifts the sheet. FIG. 5 is a cross-sectional view showing a configuration of a control block while cutting the image forming apparatus shown in FIG. 4 at a BB position. 1 is a perspective view of an image forming apparatus according to a first embodiment. It is a figure which shows 2nd Embodiment, and is sectional drawing which expands and shows an auxiliary member and its peripheral part when an auxiliary member exists in a raise position. It is a figure which shows 2nd Embodiment, and is sectional drawing which expands and shows an auxiliary member and its peripheral part when an auxiliary member exists in a lowered position. FIG. 6 is a diagram illustrating a third embodiment, and is a cross-sectional view of the image forming apparatus cut at the same position as the BB position of image formation illustrated in FIG. 4. FIG. 10 is a diagram illustrating a fourth embodiment, and is a perspective view of an image forming apparatus. It is a figure which shows 4th Embodiment and is AA sectional drawing shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image forming part 15 Paper discharge tray 16 Rotation fulcrum 17 Auxiliary member 18 Cam 23 Sheet 28 Sheet detector 29 Side wall 30 Paper discharge part (paper discharge apparatus)
32 discharge port 33 control unit 35 sheet stacking surface 37 drive source

Claims (10)

  A discharge tray for stacking sheets discharged from the discharge port, a side wall surrounding the sheet stacking surface of the discharge tray, an auxiliary member provided on a part of the sheet stacking surface of the discharge tray, and a drive for driving the auxiliary member The auxiliary member is movable up and down, and the auxiliary member moves upward by driving the drive source, so that only a part of the peripheral edge of the sheet placed on the sheet stacking surface is placed on the sheet on the discharge tray. A paper discharge device that lifts upward from a loading surface.   The paper discharge device according to claim 1, wherein the auxiliary member is provided on one end side of the sheet stacked on the paper discharge tray in the left-right direction perpendicular to the discharge direction.   A holding member that holds the auxiliary member and the drive source, and a retracting mechanism that lowers the holding member, and in the state where the auxiliary member is in an upper position where the stacked sheets are lifted, an external force that is greater than or equal to a predetermined value is applied to the auxiliary member in the downward direction. The paper discharge device according to claim 1, wherein the retracting mechanism lowers the holding member when the is operated.   The sheet stacking surface of the discharge tray is inclined with the downstream side in the sheet discharge direction upward from the discharge port, and the auxiliary member has a rotation fulcrum, and the leading end is rotated by rotating about the rotation fulcrum. The sheet discharge device according to any one of claims 1 to 3, wherein the sheet discharge device is configured to move up and down, and the auxiliary member is provided with a rotation fulcrum and a front end along the sheet discharge direction.   The side wall of the paper discharge tray has a recess on at least a part of the upper surface, and when the auxiliary member is in the upper position, the lowermost sheet is positioned above the upper surface of the recess. The paper discharge device according to any one of claims 1 to 4.   The paper discharge device according to any one of claims 1 to 5, wherein the auxiliary member is installed on the upstream side of the central portion of the paper discharge direction on the sheet stacking surface of the paper discharge tray.   A discharge roller provided at a sheet discharge port and a drive source of the discharge roller are provided, and the drive source of the discharge roller is used as a drive source of the auxiliary member. The paper discharge device according to the item.   8. A sheet detector for detecting the presence or absence of a sheet on a sheet discharge tray, and the auxiliary member is operated only when the sheet detector detects a sheet on the sheet discharge tray. The paper discharge device according to claim 1.   An image forming apparatus comprising the paper discharge device according to claim 1, wherein a sheet on which an image is formed by an image forming unit is discharged from a discharge port of the paper discharge device to a paper discharge tray. .   An input means for inputting the number of sheets to be imaged and a counting means for counting the number of sheets discharged from the discharge port of the paper discharge device, the number of sheets counted by the counting means match the number of input means The image forming apparatus according to claim 9, wherein the driving source drives the auxiliary member upward.

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