JP3933865B2 - Paper feeding device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet feeding device in which a pair of sheet storage units are provided side by side, and in particular, a sheet feeding mechanism of a first sheet storage unit and a mechanism for transferring sheets of a second sheet storage unit to the first sheet storage unit. And an image forming apparatus having the same.
[0002]
[Prior art]
Copiers, printers, fax machines, printing devices, and the like are known as image forming apparatuses that pass a sheet through a sheet passing path from a sheet feeding unit to a sheet discharging unit and form a desired image on the sheet through the sheet passing path. It is used properly according to the application. The paper feed unit used in these image forming apparatuses stacks paper on its mounting table, separates the paper one by one by a paper feed roller, etc., and feeds it to the paper feed path. A desired image is formed, and the paper is sent to a paper discharge unit at the downstream end of the paper path.
[0003]
Such image forming apparatuses tend to be multi-functional, and accordingly, the sizes of sheets on which images can be formed are diversified and the number of sheets is increasing. For this reason, a plurality of types of paper feed trays are dispersedly arranged in the paper feed unit, and these selectively feed paper to feed the image forming process unit in the paper passing path.
In such a paper feed unit, paper feed trays having different sizes according to the paper size are distributed, and in particular, a paper with a large amount of consumption can accommodate a large number of paper bundles on a mounting table having a lifting function. A paper tray is used. In this case, if the paper is of a relatively small size, an air space tends to be generated on the rear side compared to other relatively large paper feed trays. In order to make effective use of this air space, there is known a paper feeding base side system in which a pair of paper storage portions are provided side by side. One example is disclosed in Japanese Patent Laid-Open No. 2000-108480.
[0004]
For example, as shown in FIGS. 12 and 13, a paper feeding apparatus that employs a paper feeding table with a plurality of paper storage units is provided with first and second paper feeding trays 110 and 120 on a paper feeding tray 100. In addition, a pair of side fences 130 and 140 facing each other are provided on each of the paper feed trays 110 and 120, and a large number of sheets P are stacked between them without collapsing. Then, the paper P on one of the paper feed trays 110 is sequentially sent to a paper passing path (not shown) by the paper feed roller 150 at the time of paper feeding. When the sheet P runs out due to use, as shown in FIG. 12B, one sheet feed table 110 is aligned with the placement surface 160 of the other sheet feed table 120, and then the other sheet feed table 120. As shown by a two-dot chain line in FIG. 12A, the paper is placed on one of the paper feed bases 110, thereby enabling a large number of image forming processes.
[0005]
[Problems to be solved by the invention]
By the way, in general, each paper feed table of the paper feed unit is provided with a pair of side fences 130 and 140 facing each other, and the facing distance (span) L1 between these side fences is adjusted according to the size of the paper P. It has been adjusted. In this case, as shown in FIG. 13A, in order to smoothly feed and convey the paper P, the facing distance L1 between the side fences 130 and 140 is set larger than the paper size. For this reason, a gap t1 is generated between the side fences 130 and 140 and the sheet bundle.
[0006]
Therefore, when the paper feed tray 100 is set, the upper end of the sheet bundle between the side fences 130 and 140 of the paper feed stands 110 and 120 as shown in FIGS. Is disrupted in the direction indicated by the arrow s, which affects the paper feeding and conveying performance. In particular, as shown in FIG. 13B, there is a case where the paper feed roller 150 is disengaged from the upper end of the paper P due to the collapse of the upper end of the paper of one paper feed table 110 and the paper P cannot be fed. Further, the misset detection member 160 mounted on the other paper feed tray 120 is brought into contact state k1, k2 at the upper end due to the collapse of the upper end of the paper of each paper feed tray 110, 120, and is closed from the open state. In this case, an erroneous set detection signal is output to the control unit of the image forming apparatus, and one of the paper feed trays 110 does not perform a lift operation and cannot return to the paper feed standby state.
[0007]
Japanese Patent Application Laid-Open No. 2000-108480 discloses a paper feeding device that employs a paper feeding table with a plurality of paper storage units. However, the upper end of a sheet bundle between a pair of side fences on each paper feeding table is disclosed. It does not give any means to prevent the collapse.
In the present invention, based on the above problems, first, the edge of the paper placed on the stacking surface is curled to utilize the stiffness of the paper, and the first and second paper storage portions are attached to the paper feeding device. An object of the present invention is to provide a paper feeding device capable of suppressing the collapse of the sheet bundle toward the opposite end when the sheet is set in the section.
Second, there is provided a paper feeding device that can prevent the sheet bundle from collapsing toward the opposite end when the first and second paper storage portions are set on the paper feeding device mounting portion without curling the paper. The purpose is to provide.
[0008]
Thirdly, an object of the present invention is to provide a paper feeding device in which a first paper storage unit, a second paper storage unit, and a paper transfer unit are provided in a paper supply tray, and these can be easily set in a paper supply device mounting unit. .
A fourth object of the present invention is to provide a paper feeding device that can easily determine the necessity of replenishing paper in the second paper storage unit by means of the load amount detection means.
[0009]
A fifth object of the present invention is to provide a paper feeding device that can prevent malfunction of the paper feeding device by an erroneous set detection means.
Sixth, to provide an image forming apparatus capable of preventing the sheet feeding control from malfunctioning by performing the image forming control using the sheet feeding apparatus according to any one of claims 1 to 5. With the goal.
[0010]
Seventhly, an object of the present invention is to provide an image forming apparatus capable of obtaining the same effect as in the case of forming an image with an electrophotographic process or forming an image with a stencil printing apparatus. .
[0011]
[Means for Solving the Problems]
  In order to achieve the above-mentioned object, the invention of claim 1 is characterized in that a first sheet storage portion in which a plurality of sheets are stacked on a first stacking surface and a substantially same surface parallel to the first stacking surface. A second sheet storage unit having a second stacking surface that can be arranged in parallel, and a sheet transfer unit that collectively transfers a plurality of sheets of the second stacking surface onto the first stacking surface. In the paper device, an upward convex portion is formed on at least one of the opposing end portions of the first stacking surface and the second stacking surface.The second sheet storage unit is provided with an erroneous set detection means for detecting whether or not the sheets stacked on the second stacking surface are normally stacked.And features.
  In this way, the paper end on the upward convex portion of the paper placed on at least one of the stacking surfaces is curled by the upward convex portion formed on at least one of the opposing end portions of the first and second stacking surfaces. . For this reason, curling of the edge of the sheet makes it possible to suppress the collapse of the sheet bundle toward the opposite end when the first and second sheet storage portions are set on the sheet feeding device mounting portion using the stiffness of the sheet.In addition, since the paper size and paper misalignment on the second stacking surface are detected by the erroneous set detection means, malfunction of the paper feeding device can be prevented.
[0012]
  According to a second aspect of the present invention, there is provided a first sheet storage portion in which a plurality of sheets are stacked on the first stacking surface, and a second stacking surface that can be arranged in parallel so as to form a continuous surface with respect to the first stacking surface. 2. A sheet feeding apparatus comprising: a sheet storage unit; and a sheet transfer unit that collectively transfers a plurality of sheets on the second stacking surface onto the first stacking surface. At least one of the surfaces is provided with a gradient that rises toward the opposite edge of each otherThe second sheet storage unit is provided with an erroneous set detection means for detecting whether or not the sheets stacked on the second stacking surface are normally stacked.And features.
  As described above, since at least one of the first stacking surface and the second stacking surface is provided with a gradient that rises toward the opposite edge of each other, the self-weight of the paper placed on at least one of the stacking surfaces is shifted in the regulation direction. Can work. For this reason, it is possible to suppress the collapse of the sheet bundle toward the opposite end when the first and second sheet storage portions are set on the sheet feeding device mounting portion without causing curling or the like on the sheets.In addition, since the paper size and paper misalignment on the second stacking surface are detected by the erroneous set detection means, malfunction of the paper feeding device can be prevented.
[0013]
According to a third aspect of the present invention, in the paper feeding device according to the first or second aspect, the first paper storage unit, the second paper storage unit, and a paper transfer unit are provided in a paper supply tray. .
As described above, since the first paper storage unit, the second paper storage unit, and the paper transfer unit are provided in the paper feed tray, the workability of setting the paper feed tray in the paper feed device mounting portion is improved.
[0014]
According to a fourth aspect of the present invention, in the paper feeding device according to the first, second, or third aspect, the stacking amount for detecting the amount of sheets stacked on the second stacking surface in the second sheet storage portion in a plurality of stages. A detection means is provided.
As described above, since the amount of paper on the second stacking surface is detected in a plurality of stages by the load amount detecting means, it is possible to easily determine the necessity of paper replenishment.
[0016]
  Claim5According to another aspect of the present invention, there is provided an image forming apparatus that allows a sheet to pass through a sheet passing path from a sheet feeding unit to a sheet discharging unit, and forms a desired image on the sheet in the sheet passing path.4The sheet feeding device according to claim 1 is provided as the sheet feeding unit.
  Thus, the image forming apparatus comprises:4Since the sheet feeding device according to any one of the above descriptions is provided as the sheet feeding unit, it is possible to suppress the collapse of the sheet bundle in the first and second sheet storage units. It is possible to prevent a malfunction such as a set detection and the like from returning to the paper feed standby state.
[0017]
  Claim6The invention of claim5In the described image forming apparatus, the image forming apparatus visualizes the latent image of the image carrier in the electrophotographic system to form a toner image, and transfers the toner image to the paper in the sheet passing path to form an image. It is characterized by doing.
  Thus, when the image forming apparatus forms an image by an electrophotographic process, the same operation and effect as in the sixth aspect can be obtained.
[0018]
  Claim7The invention of claim5In the image forming apparatus described above, the image forming apparatus is a stencil printing apparatus that winds a master on an outer peripheral surface of a plate cylinder and performs printing on a sheet of the sheet passing path.
  Thus, even when the image forming apparatus is a stencil printing apparatus,5The same action and effect can be obtained.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show an electrophotographic copying machine (hereinafter simply referred to as a copying machine) 1 as an image forming apparatus using a sheet feeding device according to a first embodiment of the present invention. The copying machine 1 includes an upper housing 501 and a lower housing 502, and a connecting means J including a pin hole J1 and a pin J2 that is fitted in the pin hole J1 without displacement in one of them. (See FIG. 2).
The lower casing 502 is mounted with a sheet feeding unit 2 constituting a sheet feeding device and a lower sheet passing path r extending from the sheet feeding unit. In the upper casing 501, an image forming process for forming a desired image on the sheet discharging unit 3, an upper sheet passing path r from the sheet feeding unit 2 to the sheet discharging unit 3, and a sheet conveyed to the sheet passing path r. Part 4 is mounted.
[0020]
The image forming process unit 4 of the copying machine 1 rotatably supports the photosensitive drum 6 on the upper housing 501 side, and around the photosensitive drum 6, a charging charger 7, an exposure device 8, a developing device 9, and a transfer device. 10 and a cleaning device 11 are arranged, and a visible image is formed on the paper P by executing an electrophotographic image forming process including a charging process, an exposure process, a developing process, and a transfer process, and after passing through the transfer process. The toner image of the sheet P is fixed on the sheet P of the transfer medium by the fixing means 30. The fixed paper P is stored in a paper discharge unit 3 including a paper discharge tray.
A main part of the exposure device 8 is disposed above the photosensitive drum 6, and an automatic document feeder (ADF) 12 is disposed on the upper wall of the upper casing 501.
[0021]
The exposure device 8 includes an automatic document feeder (ADF) 12 or a manual light source 14 for irradiating light on the document O placed on the contact glass 13 by manual feed, and a reflected light image from the document O on the photosensitive drum 6. The exposure optical system is composed of a mirror group 15 and a lens 16 for exposing upward. The exposure apparatus 8 is an example of an analog exposure optical system, but a method of performing optical writing on the photosensitive drum 6 according to an image signal using a laser scanning optical system using a laser light source and a deflector. In this case, it can function as a laser printer, and if a document reading device is installed between the automatic document feeder (ADF) 12 and the exposure device 8, it is possible to adopt a configuration of a digital copying machine or a facsimile machine. It is.
[0022]
A paper feeding unit 2 is provided in the lower casing 502 of the copying machine 1, and the paper feeding unit 2 is connected to a paper feeding path r. A sheet feeding roller group 20, pickup rollers 21a and 21b, and registration rollers 22 are arranged on a sheet passing path r from the sheet feeding unit 2 to the sheet discharging unit 3, and these are driven and controlled by a control unit (not shown). Thus, it is possible to control the conveyance of the sheet in the sheet passing path r.
The paper feed unit 2 includes a first paper feed tray 17 on which relatively small paper P can be stacked, and a second paper feed tray 18 on which large paper PL can be stacked. The first paper feed tray 17 is provided with first and second paper storage portions 23 and 24 in the horizontal direction. A pickup roller 21 a is provided above the first paper storage portion 23, and a second paper supply tray 18 is provided above the second paper supply tray 18. Each pickup roller 21b is rotatably arranged.
The first and second paper storage portions 23 and 24 include first and second placement tables 27 and 28, respectively, and are formed on the first and second placement surfaces f1 and f2 so that sheets P of the same size can be stacked. The
[0023]
  The first loading table 27 of the first sheet storage unit 23 is a first sheet feeding tray via a guide member (not shown).17It is supported so that it can move up and down.
[0024]
As shown in FIGS. 1 and 4, a push-up mechanism 29 that is driven up and down by a motor M <b> 1 as drive means is mounted in the first paper feed tray 17, and the push-up mechanism 29 is coupled to the first mounting table 27. . The push-up mechanism 29 is slidably supported by a motor M1 supported by the first paper feed tray 17, a pinion 291 rotated by the motor M1, and a guide rail 294 supported by the first paper feed tray 17. And a rack 292 that is moved up and down by a pinion 291. An arm 293 is integrally coupled to the upper end of the rack 292, and this is fitted into the fitting portion 271 of the first mounting table 27, thereby forming a rack and pinion type push-up mechanism portion 29. The push-up mechanism 29 can be a pantograph type or chain drive type lifting mechanism (not shown) instead of the rack and pinion type.
[0025]
In the vicinity of the pickup roller 21a shown in FIG. 1, a separation roller pair 32 including a driving roller 32a and a driven roller 32b is disposed. The pickup roller 21a and the drive roller 32a are rotatably supported by the bracket 33 as shown in FIG. The bracket 33 is swingably supported by a side plate (not shown) of the lower housing 502 around the support shaft 32c of the drive roller 32a, and the end of the side opposite to the side supporting the pickup roller 21a is pulled. One end of the coil spring 34 is attached. A pulley 35 is attached to the pickup roller 21a, and two pulleys 32d are attached to the drive roller 32a. An endless belt that transmits driving force from a motor M2 provided in the lower housing 502 is attached to the pulley 32d. 36 is stretched, and an endless belt 37 is stretched between the pulleys 35 and 32d.
[0026]
A rack 39 is attached to the other end of the tension coil spring 34 so as to be movable up and down on the side plate of the lower housing 502. A pinion 38 that meshes with the rack 39 is connected to the output shaft in the vicinity of the rack 39. A stepping motor M3 is provided. With this configuration, when the stepping motor M3 rotates and the rack 39 moves upward, the bracket 33 swings counterclockwise about the support shaft 32c, and the paper feed pressure of the pickup roller 21a with respect to the paper P increases. .
[0027]
As shown in FIG. 5, the driven roller 32b is supported by a guide member (not shown) provided in the lower housing 502 so as to be movable up and down and rotatable, and one end of a compression coil spring 42 is attached to the support shaft 32e. ing. The other end of the compression coil spring 42 is attached to a rack 43 that is supported by a side plate (not shown) of the lower housing 502 so as to be movable up and down. In the vicinity of the rack 43, a pinion 44 that meshes with the rack 43 on its output shaft. A stepping motor M4 having is provided. With this configuration, when the stepping motor M4 rotates and the rack 43 moves upward, the compression coil spring 42 is compressed and the separation pressure of the driven roller 32b with respect to the drive roller 32a increases.
[0028]
  As shown in FIGS. 1 and 3, the first mounting table 27 detects a presence or absence of a pair of side fences 45 that guide the width direction of the paper P and the paper P on the first mounting table 27. One sheet presence / absence detection sensor 41 (see FIG. 1) is provided. The first paper feed tray17A guide wall 46, which is a vertical wall surface that aligns the leading ends of the sheets of the first mounting table 27, is formed at a portion of one side of the first mounting table 27 facing the holding space of the side fences 45.
[0029]
  Next, the second paper storage unit 24 includes a second placement table 28, which is a first paper feed tray.17When the paper P on the first mounting table 27 is used up, the paper P on the second mounting table 28 is collectively moved onto the first mounting table 27 in the second paper storage unit 24 fixed inside. A sheet moving member 48 (see FIG. 9), a side fence 49 that guides the width direction of the sheet P, a second sheet presence / absence detection sensor 51 that detects the presence / absence of the sheet P on the second sheet feeding tray 29, A set detection means 57 and a remaining amount detection sensor 77 for detecting the remaining amount of the paper P on the second paper storage unit 23 in a plurality of stages are provided.
[0030]
The erroneous set detection means 57 is mounted on the side wall portion of the second mounting table 28 via a bracket 572, and an erroneous set detection member 571 that can rotate around the vertical axis is pivotally supported on the bracket 572. The position is formed so as to be detected by a position sensor (not shown). Here, when the sheet P bundle is normally stacked, if the erroneous set detection member 571 reaches the steady position q1 and the upper end side of the sheet P bundle is misaligned, for example, as shown in FIGS. If the set detection member 571 is in contact with the upper end of the sheet k1 and k2 and does not return to the steady position q1, the set detection member 571 cannot return from the open state to the closed state, and outputs an erroneous set signal to a control means (not shown). The
[0031]
The sheet moving unit 48 is integrally coupled to a slider-like member 481 that is slidably attached along a guide long groove 53 (see FIG. 9) formed in the center of the second mounting table 28 so as not to be detached. And a feed screw mechanism 483 connected to a slider-like member 481. In this case, when the sheet moving unit 48 receives a transfer command from a control unit (not shown), it drives a motor (not shown) of a feed screw mechanism 483 provided at the lower part of the second mounting table 28 to thereby move the slider-like member 481 and the fence 482. Is pushed along the guide long groove 53 (see FIG. 9 (a-1)), and the sheet P bundle of the second mounting table 28 is pressed and moved toward the first mounting table 27, so that the return operation can be performed. . In some cases, a manual operation structure is employed in which the slider-like member 481 and the fence 482 are manually pressed along the guide long groove 53 to press and move the sheet P bundle of the second mounting table 28 toward the first mounting table 27. Also good.
[0032]
Here, the first and second placement tables 27 and 28 of the first and second sheet storage portions 23 and 24 are parallel to each other, and when the first placement table 27 reaches the lower end position (see FIG. 4), The first and second mounting surfaces f1 and f2 are formed so as to be arranged in parallel while maintaining substantially the same surface. In particular, the first placement surface f1 is formed with an upward convex portion A1 having an arcuate cross section at the end facing the second stacking surface f2 in the direction of the paper width, which is the direction perpendicular to the paper surface. The top portion of the upward convex portion A1 and the second placement surface f2 are supported on substantially the same surface, whereby both portions form a continuous surface.
[0033]
In the vicinity of the pickup roller 21b facing the second paper feed tray 18 on which large-size paper PL can be stacked, a separation roller pair 54 including a driving roller 54c and a driven roller 54b is disposed. Each roller 21b, 54c, 54b is rotatably supported by a bracket (not shown) that is swingably supported by the lower housing 502 around a support shaft (not shown), and from a motor (not shown) provided in the lower housing 502. Is driven to rotate.
[0034]
In addition, the second paper feed tray 18 is equipped with a push-up mechanism (not shown) that operates in conjunction with the tray mounting, so that the paper PL can be pressed against the pickup roller 21b. Further, the second paper feed tray 18 has a third paper size detection sensor 55 that detects the size of the paper PL and a third paper presence or absence that contacts the paper P and detects the presence of the paper PL on the second paper feed tray 18. A detection sensor 56 (see FIG. 1) is disposed.
[0035]
When the image forming operation is started in the image forming process unit 4 during the operation of the copying machine 1 in FIG. 1, the photosensitive drum 6 is charged by the charging charger 7, and the original image from the exposure device 8 is exposed and statically exposed. An electrostatic latent image is formed. This electrostatic latent image is developed and visualized by the two-component developer or the one-component developer of the developing device 9, and a toner image is formed on the photosensitive drum 6 of the image carrier. This toner image is transferred by a transfer device 10 to paper P and PL conveyed along a paper passage path r from a paper feed unit 2 to be described later, and the transferred paper P is fixed with a toner image by fixing means 30. It is stored in the paper discharge unit 3.
[0036]
  Prior to this, the control means (not shown) has a first paper feed tray.17The first and second paper presence / absence detection sensors 41 and 51 detect the presence / absence of the paper P on the first and second paper storage units 23 and 24, and the presence / absence of the paper on the second paper feed tray 18 is third. The remaining amount sensor 77 detects the amount of sheets stacked on the second stacking surface f2 on the second sheet storage unit 23 in a plurality of stages. Further, the erroneous setting detection means 57 detects whether or not the upper end side of the sheet P bundle of the second mounting table 28 is misaligned. Since the remaining amount detection sensor 77 detects the amount of sheets stacked on the second stacking surface f2 in a plurality of stages, it is possible to easily determine the degree of necessity of sheet supply and predict the sheet supply timing.
[0037]
Here, when all the sheets P are stacked at the proper positions, the control unit is held in a sheet feeding standby state, and starts to drive the above-described image forming process unit 4 in response to a copy command.
When a paper size abnormality or a wrong set is detected, it is not possible to return to the paper feed standby state, and a wrong set is displayed on an operation panel (not shown). In response to this, the operator replaces the sheets P and PL on the first and second sheet feed trays 17 and 18 with appropriate states.
Further, when it is detected that there is no paper P on the first loading table 23 of the first paper feed tray 17 and no paper PL on the second paper feed tray 18, the control means displays a paper out indication, and the operator Paper is supplied to the tray.
[0038]
As shown in FIGS. 8A-1 and 8A-2, the first paper feed tray 17 is set in advance with the appropriate amount of paper P bundles on the first and second mounting tables 27, 28 in advance. deep. Then, by setting the first paper feed tray 17 on the lower casing 502, the first mounting table 27 is held in an interlocked state with the arm 293 of the push-up mechanism 29, and the upper end of the sheet P bundle is pressed against the pickup roller 21a. And the copying machine 1 is set in a paper feed standby state.
[0039]
When the consumption of the paper P progresses and the paper P on the first loading table 23 of the first paper feed tray 17 runs out as shown in FIGS. 8B-1 and 8B-2, the control means (not shown) The first mounting table 27 is lowered and held in parallel with the second mounting table 28. In this state, as shown in FIGS. 9A-1 and 9A-2, the operator presses the sheet moving member 48 along the guide long groove 53 toward the first mounting table 27, and the second mounting table. 28 sheets P are moved to the first placement surface f1 of the first placement table 27. As a result, as shown in FIGS. 9B-1 and 9B-2, the paper P of the second mounting table 28 is transferred to the first mounting surface f1 of the first mounting table 27. Then, the first paper feed tray 17 is set in the lower housing 502, whereby a control unit (not shown) detects the paper set, drives the push-up mechanism 29, and the upper end of the paper P bundle is placed on the pickup roller 21a. Lifting is performed until the pressure contact is made, and the copying machine 1 is set in a paper feed standby state.
[0040]
During the transfer of the bundle of sheets P, as shown in FIG. 6A, the second placement surface f2 of the second placement table 28 and the upward convex portion A1 of the first placement surface f1 facing the second placement surface f1 are approximately. At the same height, on the continuous surface, the paper P is smoothly transferred. In addition, the sheet P after passing through the upward convex portion A1 is curled by pushing up only the end portion facing the upward convex portion A1.
[0041]
For this reason, the edge of the paper P is curled so that the stiffness of the paper P can be used. After the stack of paper is properly stacked, the upper end side of the paper P collapses and displaces in the opposite end direction s1 due to impact or vibration. Can be suppressed. In particular, the impact caused by the speed when the first paper feed tray 17, that is, the first and second paper storage portions 23 and 24 are set in the paper feed device mounting area E in the lower housing 502, It is possible to easily prevent the upper end side of the sheet bundle from being shifted in the arrow direction s as shown in FIG. 12, for example, despite being properly stacked by the applied vibration or the like. For this reason, the erroneous setting detection means 57 detects an erroneous setting due to a deviation of the upper end side of the sheet P bundle and the copying machine 1 falls into a state in which it cannot be set in the paper feed standby state, or the pickup roller 21a moves to the upper end of the sheet P bundle. Therefore, it is possible to prevent the paper feeding function from being accurately performed and preventing a misfeed state.
[0042]
As described above, the upward convex portion A1 is formed at the end of the first placement surface f1 facing the second placement surface f2, but instead of this, as shown in FIG. An upward convex portion A2 may be formed in the paper width direction (perpendicular to the paper surface) at the end of the second placement table 28 opposite to the first placement surface f1 of the second placement surface f2. One sheet feeding tray 17, that is, the first and second sheet storage portions 23 and 24, is impacted by the speed when the sheet feeding device mounting area E is set. For example, it is possible to easily prevent the upper end side from deviating in the arrow direction s as shown in FIG. 12, and to prevent the copying machine 1 from being set in the paper feed standby state.
[0043]
In the above description, the first and second mounting surfaces f1 and f2 are formed with the upward convex portions A1 and A2 at either one of the opposing end portions. On the second placement surfaces f1 and f2, upward convex portions A1 and A2 may be formed at opposite ends of each other. In this case, both sheet bundles of the first and second sheet storage portions 23 and 24 are formed. Is prevented from collapsing due to impact when the first paper feed tray 17 is set in the paper feed device mounting area E, vibrations applied over time, etc. It is possible to prevent the paper from being set in the paper standby state or falling into a misfeed state.
[0044]
Furthermore, upward convex portions A1 and A2 are formed on at least one of the first and second placement surfaces f1 and f2 of the first and second paper storage portions 23 and 24, but instead of this, FIG. As shown to a) and (b), the 1st, 2nd mounting surface which provided the gradient (alpha) which raises as one of the 1st, 2nd paper accommodating parts 23 and 24 approaches a mutual opposing edge. You may form f1 'and f2'. Also in this case, the second mounting surface f2 of the second mounting table 28 and the gradient upper end of the first mounting surface f1 ′ opposite to the second mounting surface f2 are set at substantially the same height, or the first mounting table 27 The first loading surface f1 and the upper end of the gradient of the second loading surface f2 ′ opposite to the first loading surface f1 are set at substantially the same height, whereby both opposing surfaces are set on the continuous surface, and the paper P is smoothly transferred. Will be. In this case, the end of the sheet P on the first and second placement surfaces f1 ′ and f2 formed with the respective gradients is pushed upward at the end facing the upper end of the gradient, so that the weight of the sheet can be shifted and act in the regulation direction. it can. For this reason, the paper feed of the first paper feed tray 17 is performed without the paper P being curled or the like, although both paper bundles of the first and second paper storage portions 23 and 24 are properly stacked. It can be prevented from collapsing due to an impact at the time of setting in the apparatus mounting area E, and the copying machine 1 can be prevented from being set in a paper feed standby state or falling into a misfeed state.
[0045]
FIG. 11 shows a stencil printing apparatus 60 as an image forming apparatus according to another embodiment of the present invention.
In the stencil printing apparatus 60, a paper feeding unit 62 is provided at the lower part of the housing 61, and a paper discharging unit 63 is provided at the upper part of the housing 61. r is mounted, and an image forming process unit 64 is arranged in the sheet passing path r, and the image forming process unit 64 performs a printing process on the paper P. Here, the paper feeding unit 62 has the same configuration as that of the paper feeding unit 2 in FIG.
[0046]
The stencil printing apparatus 60 includes a cylinder-shaped plate cylinder 65 inside, and a master 66 made on the peripheral surface of the plate cylinder 65 is attached to the master 66 by an attaching / detaching mechanism (not shown). Ink is supplied by an arranged ink supply mechanism (not shown), conveyed to the surface of the master 66, and transferred onto the stacked paper P through the perforations of the master 66. . The plate cylinder 65 is rotationally driven by a drive motor 67 in the direction of the arrow shown. The plate cylinder 65 is provided with a configuration for starting the feeding of the paper from the paper supply unit 62 by the pickup roller 21 a and the like, and this configuration is a shielding member 68 provided on the peripheral surface of the plate cylinder 65. And a paper feed roller trigger sensor 69 disposed in the moving path of the shielding member 68.
[0047]
The paper feeding unit 62 for feeding the paper P to the plate cylinder 65 is a pickup roller 21a, a paper feeding roller group 20, and the paper feeding roller group 20, which are arranged in order from the upstream side in the paper P feeding direction indicated by the arrow A. A configuration for discharging the paper P which has been configured by the registration unit 71 and the paper pressing unit 72 and has received the image transfer from the master 66 on the plate cylinder 65 is that of the plate cylinder 65 in the feeding direction of the paper P. The separation claw 73, the discharge roller pair 74, and the discharge tray 63 are disposed behind the plate cylinder 65 corresponding to the downstream side. The separation claw 73 peels off the paper P adhered to the master 66 of the plate cylinder 65 with the ink, and the paper P peeled off by the separation claw 73 is nipped and conveyed by a roller pair 74 to form a discharge tray. The paper is discharged to the paper discharge unit 63.
[0048]
The paper feed unit 62 is capable of stacking a first paper feed tray 17 (paper feed device) that houses first and second paper storage units 23 and 24 that can stack paper P of the same size, and a large size paper PL. The second paper feed tray 18 is provided, the pickup roller 21a passes the paper P in the first paper storage section 23 in the first paper feed tray 17, and the pickup roller 21b passes the paper PL in the second paper feed tray 18. It is configured to be sent to the registration unit 71 of the route r.
[0049]
The registration unit 71 is composed of a pair of rollers facing each other across the conveyance path of the paper P. The lower registration roller 71a located on the lower side of the transport path is rotated by the rotational force transmitted from the drive motor 67 of the plate cylinder 65, and a displacement mechanism (not shown) with respect to the upper registration roller 71b. It is comprised so that it can contact / separate periodically with the drive force from the drive motor 67 via. The contact timing of the lower registration roller 71a is determined by, for example, the upper registration roller 71b before the leading edge of the paper P fed from the pickup roller 21a reaches the registration unit 71 due to the cam profile provided in the displacement drive mechanism. The upper registration roller 71b is rotated when the lower registration roller 71a starts to rotate when the rotational force from the drive motor 67 side is transmitted after the lower registration roller 71a comes into contact. It is like that.
[0050]
During the operation of the stencil printing apparatus 60, a control unit (not shown) drives the drive motor 67 in response to a printing command, and, for example, a rotational force is transmitted to the pickup roller 21a, whereby the first paper feed is performed. The paper P in the first paper storage unit 23 in the tray 17 is fed out, and it is determined whether or not the passage of the front end of the paper is detected by the paper passage sensor 74, and the registration unit 71 is driven according to the detected time to 65, printing on the paper P that has received image transfer from the master 66 at an appropriate timing is performed and discharged to the paper discharge unit 63.
[0051]
In the paper feeding unit 62 of the stencil printing apparatus 60, as in the paper feeding unit 2 in the copier 1 of FIG. 1, the first and second placement surfaces f1, f1 of the first and second paper storage units 23, 24 are used. In f2, an upward convex portion A1 (see FIG. 4) is formed on at least one of the opposing end portions. In this case, both the sheet bundles of the first and second sheet storage portions 23 and 24 are formed. Despite being properly stacked, these bundles of sheets collapse due to vibrations applied over time and impact when set in the sheet feeding device mounting area E provided at the bottom of the casing 61 of the first sheet feeding tray 17. This can prevent the stencil printing apparatus 60 from being set in a paper feed standby state or being in a misfeed state.
In the above description, the image forming apparatus is described as the copying machine 1 or the stencil printing apparatus 60. However, the present invention is not limited to this, and the present invention may be applied to a facsimile, a digital copying machine, and the like. The same effects as those of the above-described copying machine 1 and stencil printing apparatus 60 can be obtained.
[0052]
【The invention's effect】
  As described above, the invention according to claim 1 is directed to the upward convexity of the paper placed on at least one of the stacking surfaces by the upward convex portion formed on at least one of the opposing end portions of the first and second stacking surfaces. In order to curl the end of the sheet on the sheet, the end of the sheet is curled, so that the sheet bundle is opposed when the first and second sheet storage units are set on the sheet feeding device mounting unit. Can suppress collapse to the end sideIn addition, since the paper size and paper misalignment on the second stacking surface are detected by the erroneous set detection means, malfunction of the paper feeding device can be prevented.
  In the second aspect of the invention, since at least one of the first stacking surface and the second stacking surface is provided with a gradient that rises toward the opposite edge of each other, the weight of the paper placed on at least one of the stacking surfaces is reduced. It can work in the direction of deviation regulation. For this reason, it is possible to suppress the collapse of the sheet bundle toward the opposite end when the first and second sheet storage portions are set on the sheet feeding device mounting portion without causing curling or the like on the sheets.In addition, since the paper size and paper misalignment on the second stacking surface are detected by the erroneous set detection means, malfunction of the paper feeding device can be prevented.
[0053]
According to the third aspect of the present invention, since the first paper storage portion, the second paper storage portion, and the paper transfer means are provided in the paper feed tray, the workability of setting the paper feed tray to the paper feed device mounting portion is improved.
According to the fourth aspect of the present invention, since the amount of paper on the second stacking surface is detected in a plurality of stages by the load amount detecting means, it is possible to easily determine the necessity of paper supply.
[0055]
  Claim5In the present invention, the image forming apparatus is the first aspect.4Since the sheet feeding device according to any one of the above descriptions is provided as the sheet feeding unit, it is possible to suppress the collapse of the sheet bundle in the first and second sheet storage units. It is possible to prevent a malfunction such as a set detection and the like from returning to the paper feed standby state.
[0056]
  Claim6The invention of claim 1 also applies when the image forming apparatus forms an image by an electrophotographic process.5The same action and effect can be obtained.
  Claim7According to the present invention, even when the image forming apparatus is a stencil printing apparatus,5The same action and effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a main part of a sheet feeding device as an embodiment of the present invention and a copier as an image forming apparatus to which the sheet feeding device is attached.
2 is an exploded perspective view showing an appearance of the copying machine of FIG. 1. FIG.
FIG. 3 is a schematic perspective view of a main part of a paper feeding device attached to the copier of FIG.
4 is an enlarged configuration diagram of an elevating mechanism unit used by the paper feeding device in FIG. 1. FIG.
5 is an enlarged configuration diagram of a support mechanism portion of a pickup roller used by the paper feeding device in FIG. 1. FIG.
6 is an enlarged cutaway view of a main part of first and second mounting tables used by the paper feeding device in FIG. 1. FIG.
7 is an enlarged cutaway view of a main part of first and second mounting tables as another embodiment used by the paper feeding device in FIG. 1. FIG.
8 is an enlarged plan view of the first and second mounting tables used by the paper feeding device in FIG. 1, in which (a-1) and (a-2) are stationary, and (b-1) and (b -2) indicates when the paper is out.
9 is an enlarged plan view of the first and second mounting tables used by the paper feeding device in FIG. 1, wherein (a-1) and (a-2) indicate the time of paper transfer, and (b-1) and (b) b-2) shows the time when the paper transfer is completed.
FIG. 10 is a schematic configuration diagram of a main part of a stencil printing machine as an image forming apparatus to which a paper feeding device according to another embodiment of the present invention is attached.
11 is a perspective view showing an external appearance of the stencil printing machine shown in FIG.
FIGS. 12A and 12B show a sheet bundle collapse state of a second sheet storage portion of a conventional sheet feeding device, where FIG. 12A is a plan view and FIG. 12B is a side sectional view.
FIGS. 13A and 13B show a sheet bundle collapse state of a first sheet storage unit of a conventional sheet feeding device, where FIG. 13A is a plan view and FIG. 13B is a side sectional view.
[Explanation of symbols]
1 Copying machine
2 Paper feeder
5 Case
21a Pickup roller
23 First paper storage section
24 Second paper storage unit
27 First mounting table
28 Second mounting table
48 Paper transport means
60 Stencil printing machine
f1, f1 'first loading surface
f2, f2 'second loading surface
r Paper path
α gradient
A1, A2 Upward convex part
P paper

Claims (7)

A second paper storage unit having a first paper storage unit in which a plurality of sheets are stacked on the first stacking surface and a second stacking surface that can be arranged in parallel so as to be substantially parallel to the first stacking surface. A sheet feeding device comprising: a section; and a sheet transporting unit that collectively transports a plurality of sheets of the second stacking surface onto the first stacking surface;
Forming an upward convex portion on at least one of the opposing ends of the first loading surface and the second loading surface ;
Wherein the second sheet storage portion the sheet feeding apparatus which is characterized that you erroneous setting detection means paper to be stacked on the second stacking surface to detect whether normal loading or provided. A first sheet storage unit configured to stack a plurality of sheets on a first stacking surface; a second sheet storage unit having a second stacking surface that can be arranged in parallel so as to form a continuous surface with respect to the first stacking surface; A sheet feeding device comprising a sheet transporting unit configured to collectively transport a plurality of sheets on the second stacking surface onto the first stacking surface;
The ramp rising closer to opposing end edges of each other in at least one of the first stacking surface and the second stacking surface provided,
Wherein the second sheet storage portion the sheet feeding apparatus which is characterized that you erroneous setting detection means paper to be stacked on the second stacking surface to detect whether normal loading or provided.   3. The paper feeding device according to claim 1, wherein the first paper storage unit, the second paper storage unit, and the paper transfer unit are provided in a paper supply tray.   The load amount detecting means for detecting the amount of sheets stacked on the second stacking surface in a plurality of stages is provided in the second sheet storage portion. Paper feeder. In an image forming apparatus for passing a sheet through a sheet passing path from a sheet feeding unit to a sheet discharging unit and forming a desired image on the sheet of the sheet passing path.
An image forming apparatus comprising the sheet feeding device according to claim 1 as the sheet feeding unit. The image forming apparatus is characterized in that a latent image of an image carrier in an electrophotographic system is visualized to form a toner image, and the toner image is transferred to a sheet in the sheet passing path to form an image. The image forming apparatus according to claim 5 . 6. The image forming apparatus according to claim 5, wherein the image forming apparatus is a stencil printing apparatus that winds a master on an outer peripheral surface of a plate cylinder and performs printing on a sheet of the sheet passing path .

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