JP2005343677A - Image forming device, paper feeding device, and paper feeding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of shortening the time until a first sheet body arrives at an image forming part from the time when printing demand is given and to provide a paper feeding device and a paper feeding method. <P>SOLUTION: This image forming device A is provided with a main body 100 and a plurality of paper feeding units 1a to 1c. The main body 100 includes the image forming part for forming image based on image information on a paper sheet S by corresponding to printing demand and at least one paper feeding part W. The paper feeding units 1a to 1c include paper feeding parts X, Y, Z, respectively. Paper sheets having the same size are stored in the paper feeding parts W, X, Z. A first paper sheet S corresponding to printing demand is fed from the paper feeding part W closest to the image forming part, and a second paper sheet S and after corresponding to printing demand are fed from the paper feeding part X or the paper feeding part Z other than the paper feeding part W closest to the image forming part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus including a plurality of sheet feeding units, a sheet feeding apparatus, and a sheet feeding method.

  An image forming apparatus is an example of a main apparatus that receives a sheet body such as a sheet from a sheet feeding apparatus. In recent years, multifunctional image forming apparatuses and printing processing speeds have been increased. For example, an image forming apparatus having a plurality of processing modes such as a copier mode, a printer mode, and a FAX mode, and a printing processing speed of one sheet or more per second has been developed. Such a high-speed image forming apparatus requires a paper feeding device capable of supplying a large amount of paper. The necessity is remarkably exhibited in the printer mode and the FAX mode in which printing is performed even when there is no user near the image forming apparatus. In particular, in the FAX mode, a large-capacity paper feeding device as described above is indispensable. When storing a large amount of information received when the user is absent at night or the like in a memory in the image forming apparatus without printing in order to prevent running out of paper, a large-capacity memory is required and the information stored in the memory is stored later. This is because time is lost when printing.

  As a means for supplying a large amount of paper to the image forming apparatus, a means for increasing the capacity of a paper feed cassette conventionally provided in the image forming apparatus and a paper feed cassette provided in the image forming apparatus are provided in the image forming apparatus. Means for arranging a large capacity sheet feeding device adjacent to each other can be considered. However, when the capacity of the paper feed cassette provided in the image forming apparatus is increased, there is a problem that the image forming apparatus becomes higher overall, and the operation unit and the display unit become higher, resulting in lower operability. Under such circumstances, development of a large-capacity paper feeding device that is disposed adjacent to the image forming apparatus apart from the paper feeding cassette provided in the image forming apparatus is underway (for example, see Patent Document 1). ).

  However, even with a large-capacity paper feeder as described above, the number of sheets stored cannot be increased without limit. The number of sheets stored is generally limited to 2000 to 4000 sheets. This is because the paper feeder has a lift-up mechanism that adjusts the height of the paper bundle at any time in order to sequentially feed the topmost paper. However, if the number of sheets stored is too large, the weight of the paper bundle becomes too high. This is because the up mechanism needs to have a sturdy configuration, which increases the size and cost of the apparatus, and makes it difficult to precisely adjust the paper height.

  Therefore, Patent Document 1 proposes a paper feeding device that includes a plurality of paper feeding units in order to increase the number of sheets to be stored, and in which the paper feeding units are arranged in several stages in the vertical direction. The paper supplied from the paper supply device is received from a paper receiving portion that communicates with the paper conveyance path of the image forming apparatus. Since the sheet receiving unit of the image forming apparatus needs to communicate with the sheet conveyance path, the position where the sheet receiving unit is provided is limited. Therefore, in the paper feeding device described in Patent Document 1, a bent portion is formed in the conveyance path in the paper feeding device from the paper feeding unit arranged at a different height from the paper receiving unit of the image forming apparatus to the paper receiving unit. Accordingly, the chance that the conveyed paper bends in the paper feeder increases, and the paper tends to be bent unnecessarily. Unnecessary bending of the paper causes a conveyance jam and a decrease in print quality. Further, in the paper feeder disclosed in Patent Document 1, when the amount of paper stored is increased, the paper feeders are further stacked in the vertical direction, and the conveyance path is further complicated, which easily causes a conveyance jam or the like.

  In order to solve the above-described problems, the applicant of the present invention proposes a paper feeding device including a plurality of paper feeding units configured to be arranged in parallel with the main device. When sheets are supplied from a plurality of sheet feeding units including a sheet feeding cassette in the image forming apparatus and a plurality of sheet feeding units arranged adjacent to each other as described above, a conventional method as shown in FIGS. Thus, paper is fed from each paper feed unit (see, for example, Patent Document 2).

  Here, with respect to the image forming unit of the image forming apparatus, a plurality of paper feeding units W arranged in parallel to the side of the image forming apparatus and a paper feeding unit W corresponding to a predetermined paper feeding cassette in the image forming apparatus. A paper feed unit X, a paper feed unit Y, and a paper feed unit Z corresponding to each paper feed unit of the paper unit are arranged, and sheets of the same size are placed in the paper feed unit W, the paper feed unit X, and the paper feed unit Z. The case where it is stored is assumed. Assume that the sheet feeding unit X, the sheet feeding unit Y, and the sheet feeding unit Z are close to the image forming unit in this order (see FIG. 1).

FIG. 8 is a diagram illustrating an example of a conventional paper feeding method when sheets of the same size are stored in the paper feeding unit W, the paper feeding unit X, and the paper feeding unit Z. FIG. 6 is a timing chart in the case of method V1 shown in FIG. FIG. 10 is a timing chart in the case of the method V3 shown in FIG. In the conventional paper feeding method, the priority of the paper feeding order is always set higher in order from the paper feeding unit closest to the image forming unit. Specifically, when the paper is stored in all of the paper feeding units W, X, and Z, as shown in the method V1, all the papers according to the print request from the paper feeding unit W closest to the image forming unit. Is fed. When the paper feed unit W runs out of paper, as shown in the method V2, all papers corresponding to the print request are fed from the paper feed unit X next to the image forming unit next to the paper feed unit W. The Further, when the paper feeding unit X runs out of paper, as shown in the method V3, all the papers according to the print request are fed from the paper feeding unit Z next to the image forming unit next to the paper feeding unit X. The
JP-A-5-193766 Japanese Patent Laid-Open No. 4-123072

  As described above, since the conventional paper feeding method always feeds paper from the paper feeding unit closest to the image forming unit, the paper feeding unit near the image forming unit tends to run out of paper. When the paper feeding unit near the image forming unit runs out of paper, the time required for transporting the paper is extended by the distance from the paper feeding unit to the image forming unit, and the first sheet after the print request is made. It takes a long time to reach the image forming unit. For example, the time required from the printing request to the transfer of the first sheet is time T2 when paper is fed from the paper feed unit W, whereas time T3 is fed when paper is fed from the paper feed unit Z. Thus, the time T3 is significantly longer than the time T2. As described above, in the conventional paper feeding method, the time from when a print request is made until the first sheet reaches the image forming unit is shortened while the paper is stored in all the paper feeding units. Although the sheet feeding unit close to the image forming unit is likely to run out of paper, the time from when a print request is made until the first sheet reaches the image forming unit is kept short over a long period of time. I couldn't.

  SUMMARY OF THE INVENTION An object of the present invention is to keep the time from when a print request is made until the first sheet reaches the image forming unit over a long period of time by preventing the paper feeding unit near the image forming unit from running out of paper. An image forming apparatus, a paper feeding device, and a paper feeding method that can perform the above.

  The image forming apparatus of the present invention is configured as follows in order to solve the above-described problems.

  (1) An image forming unit that forms an image based on image information in response to a print request on a sheet member, and a plurality of sheet feeding units that respectively store sheet members of the same size to be supplied to the image forming unit. In the image forming apparatus, the first sheet body corresponding to the print request is fed from a paper feeding section closest to the image forming section, and the second and subsequent sheet bodies corresponding to the print request are fed to the image. Paper is fed from a paper feeding unit other than the paper feeding unit closest to the forming unit.

  In this configuration, a plurality of paper feed units that store sheets of the same size are arranged. Since the first sheet corresponding to the print request is fed from the paper feed unit closest to the image forming unit, the time from when the print request is made until the first sheet reaches the image forming unit Is kept short. In addition, since the second and subsequent sheets are fed from a sheet feeding unit other than the sheet feeding unit closest to the image forming unit, the sheet feeding unit closest to the image forming unit is prevented from being out of paper.

  (2) A main body including at least one paper feeding unit among the image forming unit and the plurality of paper feeding units, and a plurality of paper feeding units configured to be arranged in parallel to a side of the main body. A plurality of sheet feeding units, and a conveyance path that conveys the sheet member in the conveyance direction from the sheet feeding unit to the image forming unit of the main body in response to the print request. A first sheet body corresponding to the printing request from the sheet feeding unit of the main body, and the second and subsequent sheet bodies corresponding to the printing request The sheet path fed from the sheet feeding unit of one of the sheet feeding units and fed from the sheet feeding unit is provided in the sheet feeding unit in which the sheet body is stored. And a feeding unit disposed downstream of the feeding unit in the transport direction. Via a conveyance path provided in the unit, characterized in that it conveyed to the image forming portion of said body.

  In this configuration, the image forming apparatus includes a main body and a plurality of paper feeding units. The main body includes an image forming unit and at least one paper feeding unit. Each paper feed unit is arranged in parallel to the side of the main body, and has a paper feed unit and a conveyance path. Since the paper supply units are arranged in parallel, the conveyance paths of the respective paper supply units are arranged in a substantially straight line, and the sheet body is conveyed without being bent in the conveyance direction. The distance between the paper feeding unit provided in the main body and the image forming unit is shorter than the distance between the paper feeding unit provided in the paper feeding unit disposed closest to the main body and the image forming unit. The first sheet body corresponding to the print request is fed from a sheet feeding unit provided in the main body, and the second and subsequent sheet bodies are one of a plurality of sheet feeding units. Paper is fed from the paper feeder. The sheet body fed from the sheet feeding unit is fed to the transport path provided in the sheet feeding unit in which the sheet body is stored, and the sheet feed disposed downstream of the sheet feeding unit in the sheet transport direction. It is conveyed to the image forming unit of the main body via a conveyance path provided in the unit.

  (3) When the next print request is made before the operation of the image forming unit relating to the sheet body supplied in response to the print request is completed, the first sheet body corresponding to the next print request is Paper is fed from any one of the plurality of paper feeding units.

  In this configuration, the operation in the image forming unit related to the sheet body corresponding to the print request for the first job has not been completed, and the print request for the second job has been made while the image forming unit is still operating. In this case, the first sheet of the second job is fed from the paper feed unit of one of the paper feed units instead of the paper feed unit of the main body. When the sheet body is fed from the sheet feeding unit of the sheet feeding unit, it takes longer to reach the image forming unit than when the sheet is fed from the sheet feeding unit of the main body. Since the operation relating to the previous sheet member has not yet been completed, the sheet member is conveyed from the paper feeding unit toward the image forming unit while the image forming unit is performing the operation relating to the previous sheet member. As soon as the operation relating to the previous sheet is completed, an image corresponding to the print request for the second job is formed.

  (4) The second and subsequent sheets are fed at a timing when they are supplied to the image forming unit according to the interval of image formation on the sheet in the image forming unit.

  In this configuration, the second and subsequent sheet bodies are fed at a timing such that useless empty time does not occur between the first sheet body and the second and subsequent sheet bodies in the image forming unit. Is started. Specifically, for example, when the first sheet member is fed from the sheet feeding unit closest to the image forming unit and the second sheet member is fed from the sheet feeding unit farthest to the image forming unit, 2 The feeding of the first sheet body is started at a predetermined timing earlier than the feeding of the first sheet body. As a result, the second sheet body is supplied without wasted time following the first sheet body in the image forming unit.

  (5) The second and subsequent sheets are fed from a sheet feeding unit other than the sheet feeding unit closest to the image forming unit among the plurality of sheet feeding units.

  In this configuration, since the second and subsequent sheets are fed from a paper feed unit other than the paper feed unit closest to the image forming unit among the plurality of paper feed units, the sheet supply closest to the image forming unit is provided. Paper out of the paper unit is suppressed.

  (6) The sheet conveying speed in the conveying path provided in the sheet feeding unit is higher than the image forming speed in the image forming unit.

  In this configuration, the sheet body fed from the paper feed unit is conveyed at high speed to the vicinity of the image forming unit.

  The paper feeding device of the present invention is configured as follows in order to solve the above-described problems.

  (7) A plurality of conveyance paths each accommodating a sheet body to be supplied to the main apparatus in a sheet feeding unit and conveying the sheet body in a conveyance direction from the sheet feeding unit to the main apparatus in response to a print request. In the paper supply device including the paper supply unit, the plurality of paper supply units are configured to be freely arranged in parallel, and a first sheet body corresponding to the print request is a sheet having a size corresponding to the print request. A sheet is fed from a sheet feeding unit that is closest to the main apparatus among the sheet feeding units that store the body, and the second and subsequent sheet bodies corresponding to the print request are stored in a sheet body having a size corresponding to the print request. A sheet feeding unit other than the sheet feeding unit closest to the main unit among the sheet feeding units feeds the fed sheet body to the sheet feeding unit in which the sheet body is stored. And the paper feed unit Via a conveyance path provided in the paper feeding unit disposed on the downstream side in the transport direction than Tsu preparative characterized by conveying to the main device.

  In this configuration, the sheet feeding device includes a plurality of sheet feeding units, and each sheet feeding unit is configured to be arranged in parallel to the side of the main device. Since the sheet feeding units are arranged in parallel, the conveyance paths of the sheet feeding units are arranged in a substantially straight line, and the sheet body is conveyed without being bent in the conveyance direction. In addition, the first sheet body corresponding to the print request is fed from the paper feed unit closest to the main apparatus among the paper feed units storing the sheet body of the size corresponding to the print request. The sheet body is fed from a sheet feeding unit other than the sheet feeding unit closest to the main apparatus among the sheet feeding units storing the sheet body of a size corresponding to the print request. A sheet body fed from a paper feeding unit closest to the main apparatus is conveyed to the main apparatus via a conveyance path provided in the paper feeding unit. A sheet body fed from a sheet feeding unit other than the sheet feeding unit closest to the main apparatus is transported from the sheet feeding unit in which the sheet body is stored, and the sheet body is conveyed from the sheet feeding unit. The sheet is conveyed to the main apparatus via a conveyance path provided in a sheet feeding unit arranged on the downstream side in the direction.

  (8) When a next print request is made before the operation of the main device relating to the sheet body supplied in response to the print request is completed, the first sheet body in response to the next print request is The sheet feeding unit is configured to feed a sheet from a sheet feeding unit other than the sheet feeding unit closest to the main apparatus among sheet feeding units storing a sheet having a size corresponding to a next print request.

  In this configuration, when the operation of the main apparatus related to the sheet body corresponding to the print request for the first job is not completed and the print request for the second job is made while the main apparatus is still operating, 2 The first sheet of the job is fed from a sheet feeding unit other than the sheet feeding unit closest to the main apparatus, not the sheet feeding unit closest to the main apparatus. When the sheet body is fed from a paper feeding unit other than the paper feeding unit closest to the main apparatus, the sheet body reaches the main apparatus as compared with the case where the sheet body is fed from the paper feeding unit closest to the main apparatus. However, since the main apparatus has not yet completed the operation related to the previous sheet body, the sheet body is directed from the sheet feeding unit to the main apparatus while the main apparatus performs the operation related to the previous sheet body. As soon as the main apparatus completes the operation related to the previous sheet, an image is formed in response to the print request for the second job.

  The paper feeding method of the present invention is configured as follows to solve the above-described problems.

  (9) In a paper feeding method in which the sheet body is fed in response to a printing request from a plurality of paper feeding units each containing a sheet body of the same size and conveyed to the image forming unit, 1 corresponding to the printing request The second sheet body is fed from the sheet feeding unit closest to the image forming unit, and the second and subsequent sheet bodies corresponding to the print request are fed other than the sheet feeding unit closest to the image forming unit It is characterized by feeding paper from.

  In this configuration, a plurality of paper feed units that store sheets of the same size are arranged. Since the first sheet corresponding to the print request is fed from the paper feed unit closest to the image forming unit, the time from when the print request is made until the first sheet reaches the image forming unit Is kept short. In addition, since the second and subsequent sheets are fed from a sheet feeding unit other than the sheet feeding unit closest to the image forming unit, the sheet feeding unit closest to the image forming unit is prevented from being out of paper.

  According to the present invention, the following effects can be obtained.

  (1) Since it is possible to suppress the paper out of the paper feeding unit closest to the image forming unit, the time from when a print request is made until the first sheet reaches the image forming unit is shortened over a long period of time. Can be suppressed.

  (2) The sheet body is conveyed without being bent in the conveyance direction, and the sheet body is not bent in the conveyance direction, so that the sheet body can be prevented from being obliquely conveyed and conveyance jammed. Further, since the first sheet body corresponding to the print request is fed from the sheet feeding unit of the main body, the distance from the sheet feeding unit to the image forming unit is the shortest, and the sheet body is imaged after the print request is made. The time required to reach the formation portion can be shortened. In addition, since the second and subsequent sheet bodies corresponding to the print request are fed from the sheet feeding unit of one of the sheet feeding units, consumption of the sheet body stored in the sheet feeding unit of the main body is suppressed. It is possible to suppress the paper out of the paper supply unit of the main body, and it is possible to reduce the time from when the print request is made until the first sheet reaches the image forming unit over a long period of time.

  (3) When the next print request is made before the operation of the image forming unit relating to the sheet body supplied in response to the previous print request is completed, the first sheet body corresponding to the next print request is supplied. Paper is fed from the paper feed unit of the paper unit, but the sheet body corresponding to the next print request is conveyed while the image forming unit performs an operation related to the sheet body supplied according to the previous print request. Therefore, the image forming operation corresponding to the next print request can be performed immediately after the image forming operation corresponding to the previous print request is completed. Accordingly, the first sheet corresponding to the next print request from the completion of the operation of the image forming unit related to the sheet body corresponding to the previous print request while suppressing the paper out of the sheet feeding unit of the main body closest to the image forming unit. The time until the start of image formation on the sheet can be kept short.

  (4) In the image forming unit, the image can be continuously formed on the sheet member without wasted time.

  (5) Since paper out of the paper feeding unit of the paper feeding unit closest to the image forming unit is suppressed, even if the paper feeding unit of the main body runs out of paper, the paper is fed to the paper feeding unit next to the image forming unit. Therefore, the time from when a print request is made to when the first sheet reaches the image forming unit can be reduced over a long period of time in accordance with the case where paper is fed from the paper feeding unit of the main body. .

  (6) Since the sheet member is conveyed at high speed to the vicinity of the image forming unit, the interval between the sheet members in the image forming unit can be reduced. Further, since the sheet body reaches the vicinity of the image forming portion quickly, a sufficient time can be taken for resist of the sheet body.

  (7) The sheet body is conveyed without being bent in the conveyance direction, and the sheet body is not bent in the conveyance direction, so that the sheet body can be prevented from being obliquely conveyed and conveyance jammed. Further, the first sheet body according to the print request is fed from the paper feed unit closest to the main apparatus among the paper feed units that store the sheet body of the size according to the print request. The distance to the main device is the shortest, and the time from when the printing request is made until the sheet reaches the main device can be kept short. The second and subsequent sheet bodies corresponding to the print request are fed from paper feed units other than the paper feed unit closest to the main apparatus among the paper feed units storing the sheet bodies of the size corresponding to the print request. Therefore, it is possible to suppress the consumption of the sheet body stored in the sheet feeding unit closest to the main apparatus among the sheet feeding units storing the sheet body of the size according to the printing request, and to suppress the printing out. The time from the request to the arrival of the first sheet at the main apparatus can be kept short over a long period of time.

  (8) If the next print request is made before the operation of the image forming unit relating to the sheet body supplied in response to the previous print request is completed, the first sheet body corresponding to the next print request is the main sheet body. A sheet is fed from a sheet feeding unit other than the sheet feeding unit closest to the apparatus, but the sheet corresponding to the next print request is being processed while the main apparatus is performing operations related to the sheet body supplied in response to the previous print request. Since the body is conveyed, the operation corresponding to the next print request can be performed immediately after the operation corresponding to the previous print request is completed. Therefore, the first sheet body corresponding to the next print request from the completion of the operation of the main apparatus related to the sheet body corresponding to the previous print request is suppressed while suppressing the paper out of the paper feeding unit closest to the main apparatus. The time to reach the main device can be kept short.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus A according to this embodiment includes a main body 100 and a paper feeding device 1. The paper feeding device 1 includes a plurality (three in this embodiment) of paper feeding units 1a, 1b, and 1c. The plurality of paper feeding units 1a, 1b, and 1c are arranged in parallel on the side of the main body 100 as an example of a main apparatus that receives the supply of the sheet body. In this embodiment, the sheet feeding device 1 supplies the sheet S as an example of a sheet body to the main body 100, but can also supply other sheet bodies such as an OHP film.

  The main body 100 forms an image on the paper S through an electrophotographic image forming process. The main body 100 includes paper feed cassettes 101, 102, and 103 at the bottom, and a paper discharge tray 104 at the top. A paper transport path F <b> 1 is provided between the paper feed cassettes 101, 102, 103 and the paper discharge tray 104. A photosensitive drum 105 is disposed in the vicinity of the paper transport path F1. Around the photosensitive drum 105, a charging device 106, an optical scanning unit 107, a developing unit 108, a transfer device 109, a cleaning unit 110, and a static elimination device (not shown) are disposed. In addition, a registration roller 111 that adjusts the timing of supplying the paper S to the transfer unit between the photosensitive drum 105 and the transfer device 109 is disposed upstream of the photosensitive drum 105 in the conveyance direction of the paper S. A fixing device 112 is disposed downstream of the drum 105.

  The charging device 106 charges the outer peripheral surface of the photosensitive drum 105 to a predetermined potential. The optical scanning unit 107 forms an electrostatic latent image on the outer peripheral surface of the photosensitive drum 105 based on image data input from the outside. The developing unit 108 supplies toner onto the outer peripheral surface of the photosensitive drum 105 to visualize the electrostatic latent image, and forms a toner image. The toner image formed on the photosensitive drum 105 is transferred to the paper S by the transfer device 109, further fixed to the paper S by the fixing device 111, and discharged to the paper discharge tray 104. The toner remaining on the outer peripheral surface of the photosensitive drum 105 after the toner image is transferred to the paper S is collected by the cleaning unit 110, and the electric charge on the outer peripheral surface of the photosensitive drum 105 is removed by the static eliminator.

  The main body 100 also includes a reversal conveyance path F2 for reversing the front and back of the sheet and conveying it to the transfer unit in order to form an image on the back side of the sheet having an image formed on one side. Further, the main body 100 includes a paper transport path F3 that joins the paper transport path F1 between the paper feed cassettes 101, 102, and 103 and the transfer unit. The paper transport path F3 is provided substantially horizontally. The paper transport path F3 is connected to a manual feed tray 113 that is provided on the side surface of the main body 100 and that supplies paper of an irregular size, and a paper receiving unit 114 that receives the paper S supplied from an external device. Alternatively, the paper supplied from the paper receiving unit 114 is conveyed to the transfer unit. The sheet S stored in the sheet feeding device 1 is supplied from the sheet receiving unit 114 of the main body 100 to the sheet conveyance path F3 and is conveyed to the transfer unit.

  FIG. 2 is a cross-sectional view showing the configuration of the paper feed unit 1c. The paper feed unit 1 c includes a mounting plate 2, a pickup roller 3, a feed roller 4, a reverse roller 5, a transport roller 6, a discharge unit 7, paper guides 8 and 9, and a receiving port 10.

  The paper S is positioned by the paper positioning plate 16 and stored in a stacked state on the placement plate 2 that is the paper feeding unit Z. The paper feed unit 1 c is formed on the placement plate 2 so as to be able to store a large amount of paper. The mounting plate 2 is moved up and down along the guide rails 13 and 14 by the lifting members 11 and 12, and the vertical position is detected by the detection sensor 15. The elevating members 11, 12 move the mounting plate 2 in the vertical direction so that the upper surface of the uppermost sheet S in the sheet bundle placed on the mounting plate 2 is at a predetermined position 18 in the height direction. Displace. In this embodiment, the detection sensor 15 also detects whether or not the sheet S is on the placement plate 2.

  The placement plate 2 is positioned at the lowest position when the paper S is replenished, and in this state, the paper S is replenished to an arbitrary position below the height of the paper loading capacity index 17. Further, when there is a paper feeding unit arranged on the upstream side in the transport direction of the paper S from the paper feeding unit 1c, the placing plate 2 is transporting the paper S from the upstream paper feeding unit, When there is no paper S on the placement plate 2 of the paper feeding unit 1 c, the placement plate 2 is not lowered to the lowest position, and the upper surface of the placement plate 2 is arranged at the height of the position 18.

  The pickup roller 3 is formed so as to be displaceable in the vertical direction. The pickup roller 3 is lowered when printing is requested, and feeds the uppermost sheet S of the sheet bundle placed on the placement plate 2. The feed roller 4 and the reverse roller 5 are disposed on the downstream side of the pickup roller 3 in the transport direction of the paper S so as to face each other. The feed roller 4 is rotationally driven in the same direction as the pickup roller 3. The reverse roller 5 is rotationally driven so that the circumferential surface moves in the direction opposite to the circumferential surface of the feed roller 4. The paper S fed by the pickup roller 3 is fed by the feed roller 4 and the reverse roller 5 and supplied to the transport path R one by one.

  A transport roller 6 is disposed downstream of the feed roller 4 and the reverse roller 5 in the transport direction of the paper S. On the transport path R and on the downstream side of the transport roller 6, a discharge unit 7 that opens to the outside of the paper feed unit 1c is provided. The sheet S fed by the pickup roller 3 and rolled by the feed roller 4 and the reverse roller 5 is further conveyed downstream by the conveying roller 6 and is discharged from the discharge unit 7 to the outside of the sheet feeding unit 1c.

  Paper guides 8 and 9 are disposed in the discharge unit 7. Each of the paper guides 8 and 9 is formed to be rotatable, and is displaced between a folded state along the side surface of the paper feeding unit 1c and a use state supported in the horizontal direction. The paper guides 8 and 9 guide the paper S discharged from the discharge unit 7 when set to the use state.

  A receiving unit 10 is provided on the upstream side of the conveyance path R of the paper S. The receiving unit 10 is provided on the side surface opposite to the side surface of the paper feeding unit 1 c where the discharging unit 7 is provided at substantially the same height as the discharging unit 7. The receiving unit 10 is open to the outside of the paper feed unit 1c, and receives the paper S supplied from the outside of the paper feed unit 1c into the paper feed unit 1c. The discharge unit 7 and the receiving unit 10 are formed so that the conveyance path R can communicate with each other when the plurality of sheet feeding units 1c are arranged in parallel in the same direction.

  The paper feed unit 1a and the paper feed unit 1b are configured in the same manner as the paper feed unit 1c.

  The paper feed units 1 a to 1 c are formed lower than the manual feed tray 113 so that the paper S can be supplied to the paper receiving unit 114 of the main body 100 without interfering with the manual feed tray 113 of the main body 100. Here, the description will be made mainly with respect to the relationship between the paper feed unit 1b and the paper feed unit 1c, but the same applies to the relationship between the paper feed unit 1a and the paper feed unit 1b. The sheet S is conveyed in a direction (leftward in FIG. 1) from the sheet supply unit 1c farthest to the main body 100 to the sheet supply unit 1a closest to the main body 100.

  In each of the paper feeding units 1b and 1c, the receiving unit 10 of the paper feeding device 1b arranged on the downstream side in the conveyance direction of the paper S and the discharge unit 7 of the paper feeding device 1c arranged on the upstream side face each other. Are arranged in parallel in the horizontal direction. The paper guides 8 and 9 of the paper feeding units 1b and 1c are set in use and are inserted into the receiving portions 10 of the paper feeding units 1a and 1b adjacent to the downstream side, respectively. By inserting the paper guides 8 and 9 into the receiving portion 10 of the paper feed unit 1b adjacent to the downstream side, the transport path R of the upstream paper feed unit 1c and the transport path R of the downstream paper feed unit 1b Is communicated.

  The paper guides 8 and 9 of the paper feeding unit 1c are mounted on the paper feeding unit 1b when the paper feeding units 1b and 1c are arranged in parallel and inserted into the receiving portion 10 of the paper feeding unit 1b adjacent to the downstream side. From the upper end of the sheet S placed on the placing plate 2 of the sheet feeding unit 1b, above the upper surface of the uppermost sheet S in the sheet bundle placed on the placing plate 2. A downstream end is formed on the downstream side. As a result, the sheet S conveyed from the sheet feeding unit 1c does not stick to the sheet S stored in another sheet feeding unit 1b adjacent to the downstream side, and the sheet S stored in the sheet feeding unit 1b. Is smoothly conveyed to the top surface of the.

  In a state in which the paper feed units 1b and 1c are arranged in parallel, the distance L1 between the pickup roller 3 of the downstream paper feed unit 1b and the transport roller 6 of the upstream paper feed unit 1c is the transported paper S Is set to be shorter than the dimension L2 in the transport direction. Specifically, for example, in the conventional paper feeding unit, the pickup roller is disposed so as to feed the paper at a position of 10 mm to 20 mm from the edge of the paper on the placing plate. In the units 1b and 1c, the pickup roller 3 is disposed so as to feed the paper S at a position of 50 mm to 60 mm from the front end portion of the paper S arranged on the placement plate 2. As a result, the sheet S is gripped by the pickup roller 3 of the sheet feeding device 1 b and conveyed by the pickup roller 3 while being gripped by the conveyance roller 6 of the sheet feeding device 1 c and being conveyed by the conveyance roller 6. Therefore, even when the paper S is transported via the plurality of paper feeding devices 1b and 1c, the transport force with respect to the paper S is not interrupted, and the transport jam is suppressed.

  The paper S supplied from the upstream paper feed unit 1c and received from the receiving unit 10 is placed on the upper surface of the uppermost paper S in the paper bundle placed on the placement plate 2 of the paper feed unit 1b. Guided and transported. That is, the upper surface of the uppermost sheet S in the sheet bundle placed on the placing plate 2 constitutes a part of the transport path R. When there is no sheet S on the placement plate 2, the sheet S being conveyed is guided and conveyed by the upper surface of the placement plate 2. In this case, the upper surface of the mounting plate 2 constitutes a part of the transport path R.

  By the driving force of the transport roller 6 of the upstream paper feed unit 1c, the paper is transported on the upper surface of the uppermost paper S in the paper stack placed on the placement plate 2 of the downstream paper feed unit 1b. The sheet S is gripped at the front end by the pickup roller 3 of the sheet feeding unit 1b that descends at a predetermined timing while being gripped by the transport roller 6 of the sheet feeding unit 1c, and is picked up by the pickup roller 3 of the sheet feeding unit 1b. Further, the sheet is conveyed and further conveyed further downstream by the conveying roller 6 of the sheet feeding unit 1b.

  As described above, in the paper feeding device 1 according to the present invention, the paper S stored in the paper feeding unit 1c is fed on the conveyance path R of the paper feeding unit 1c and on the downstream side of the paper feeding unit 1c. It is transported to the main body 100 via the transport path R of the units 1a and 1b. That is, the transport path R of each paper feed unit 1a, 1b having a paper feed unit arranged on the upstream side is used for transporting the paper S stored in each paper feed unit 1a, 1b itself and each paper feed unit 1a. , 1b, and for conveying the paper S stored in the paper feeding units 1b, 1c arranged on the upstream side.

  In this embodiment, the transport speed of the paper S in the transport path R of each of the paper feed units 1 a to 1 c is set higher than the speed of the image forming process in the image forming unit of the main body 100. Further, the transport speed of the paper transport path F3 from the paper receiving unit 114 of the main body 100 to the registration roller 111 is set to be equal to the transport speed of the transport path R of the paper feed units 1a to 1c.

  FIG. 3 is a block diagram illustrating a schematic configuration of the image forming apparatus A. A control unit 121 is provided in the main body 100 of the image forming apparatus A. Based on the image information, the control unit 122 receives various information display and setting condition input operations, for example, an operation unit 122 embodied by a touch panel, an external I / F 123 to which image information or the like is input from an external device, and the image information. A print data generating unit 124 that generates print data, an image forming unit 125 including a developing unit load device 126, a transfer unit load device 127, and a fixing unit load device 128, and pickup rollers of the paper feed cassettes 101 to 103. The paper feed unit load device 129, the transport unit load device 130 including transport rollers and the like disposed in the paper transport paths F1 to F3, and the paper feed units 1a to 1c are connected. The sheet feeding unit 1 a includes a transport unit load device 131 including the pickup roller 3 and the transport roller 6, a lifting member load device 132 including the lifting members 11 and 12, and a detection sensor 15. The sheet feeding units 1b and 1c are the same as the sheet feeding unit 1a. The control unit 121 controls the input / output devices as described above.

  For convenience of explanation, the paper feed cassette 101 of the main body 100 is fed by the paper feed unit W, the paper S storage position in the paper feed unit 1a is fed by the paper feed unit X, and the paper S storage location by the paper feed unit 1b is fed. It will be called a paper portion Y. Further, as described above, the storage position of the paper S in the paper supply unit 1c is referred to as a paper supply unit Z.

  FIG. 4 is a diagram illustrating an example of a paper feeding method when the paper S of the same size corresponding to the print request is stored in the paper feeding unit W, the paper feeding unit X, and the paper feeding unit Z. As shown in the method U1, when the paper feeding units X and Y are out of paper, all the paper is fed from the paper feeding unit W of the main body 100. As shown in the method U2, when the paper feeding unit Z is out of paper, the first sheet is fed from the paper feeding unit W of the main body 100, and the second and subsequent sheets are fed by the paper feeding unit 1a closest to the main body 100. Paper is fed from part X.

  Further, when all of the paper feeding units W, X, and Z are not out of paper, the paper is fed by a method as shown in, for example, the methods U3 to U5. In the method U3, the first sheet is fed from the sheet feeding unit W of the main body 100, the second sheet is fed from the sheet feeding unit X of the sheet feeding unit 1a closest to the main body 100, and the third and subsequent sheets are fed from the main body 100. The paper is fed from the paper feeding unit Z of the paper feeding unit 1c other than the paper feeding unit 1a closest to. In the method U4, the first sheet is fed from the sheet feeding unit W of the main body 100 as in the method U3, and the second and third sheets are fed from the sheet feeding unit X of the sheet feeding unit 1a. Thereafter, paper is fed from the paper feed unit Z of the paper feed unit 1c. In the method U5, the first sheet is fed from the sheet feeding unit W of the main body 100 in the same manner as the methods U3 and U4, and the second and subsequent sheets are fed from the sheet feeding unit 1c other than the sheet feeding unit 1a closest to the main body 100. Paper is fed from part Z.

  Further, when the paper feeding unit W runs out of paper, the first sheet is fed from the paper feeding unit X of the paper feeding unit 1a closest to the main body 100, and the second and subsequent sheets are fed by the paper feeding unit 1c. Paper is fed from part Z.

  FIG. 5 is a timing chart in the case of the method U3 shown in FIG. When there is a print request, the first sheet S is fed from the sheet feeding unit W of the main body 100, chucked by the registration roller 111, conveyed to the transfer unit, and the image is transferred to the sheet S. In addition, during the process of feeding the first sheet S from the sheet feeding unit W, feeding of the second sheet S from the sheet feeding unit X is started, and the second sheet S is changed to the first sheet S. It waits in front of the registration roller 111 until the transfer process is completed. Further, the third sheet feeding process is started from the sheet feeding unit Z while the feeding process of the first and second sheets S is not completed, and the transport path R of the sheet feeding unit Y and the sheet feeding unit W is started. Is then chucked by the registration roller 111 and conveyed to the transfer section. As described above, since the paper feeding unit Z to which the third paper S is fed is long from the transfer unit, the third paper S is loaded at such a timing that no unnecessary empty time is generated in the transfer unit. Feeding of the third sheet S is started so as to reach the transfer unit. Therefore, in the transfer unit, images are continuously transferred onto the paper S while maintaining a predetermined interval in a state where there is no wasted time according to the speed of the image forming process of the image forming unit.

  Note that the above-described control can be applied not only to paper feeding within one job but also when a plurality of jobs are executed continuously. That is, for example, when the print request for the next second job is made while the photosensitive drum 105 is rotating, such as during the cleaning of the photosensitive drum 105, after the final transfer process of the first job is completed. The first sheet S of the second job is fed from the sheet feeding unit X or the sheet feeding unit Z instead of the sheet feeding unit W.

  According to the image forming apparatus A, the paper S is transported almost without being bent in the transport direction, and the paper S is not bent in the transport direction, so that it is possible to prevent the paper S from being obliquely transported and transport jammed. . Further, since the first sheet S corresponding to the print request is fed from the sheet feeding unit W of the main body 100, the distance from the sheet feeding unit to the image forming unit is the shortest, and the sheet S is printed after the print request is made. The time T1 until the image reaches the image forming unit and the image is transferred to the paper S can be shortened. Further, since the second and subsequent sheets S corresponding to the print request are fed from the sheet feeding unit of one of the sheet feeding units, they are stored in the sheet feeding unit W of the main body 100 closest to the image forming unit. It is possible to suppress the consumption of the sheet S that is present, and to prevent the sheet feeding unit W of the main body 100 from running out of paper, and the time from when a print request is made until the first sheet S reaches the image forming unit is extended. Over a short period of time.

  Further, when the next print request is made before the operation of the image forming unit relating to the paper S supplied in response to the previous print request is completed, the first sheet S corresponding to the next print request is the main body 100. The sheet is fed from the sheet feeding unit of the sheet feeding unit instead of the sheet feeding unit W, but the next print request is made while the image forming unit is performing an operation related to the sheet S supplied in response to the previous print request. Therefore, the sheet forming operation corresponding to the next print request can be performed immediately after the image forming operation corresponding to the previous print request is completed. Accordingly, while suppressing the paper out of the paper feeding unit W of the main body 100 closest to the image forming unit, 1 corresponding to the next print request from the completion of the operation of the image forming unit regarding the paper S corresponding to the previous print request. The time until the start of image formation on the first sheet S can be shortened.

  Further, the second and subsequent sheets S are started to be fed so as to reach the transfer section at a timing that does not cause useless empty time in the transfer section. Formation can be performed continuously without wasted time.

  Further, when the second and subsequent sheets are fed from the sheet feeding unit of the sheet feeding unit other than the sheet feeding unit 1a closest to the main body 100, the sheet feeding of the sheet feeding unit 1a closest to the image forming unit is performed. Since the paper out of the part X is suppressed, even when the paper feeding unit W of the main body 100 runs out of paper, the paper remains in the paper feeding unit X next to the next image forming unit, and the paper feeding of the main body 100 The time from when a printing request is made to when the first sheet S reaches the image forming unit can be reduced over a long period of time in accordance with the case of feeding from the unit W.

  Further, since the sheet S is conveyed at high speed to the vicinity of the image forming unit, the interval between the sheets S in the image forming unit can be reduced. In addition, since the paper S reaches the vicinity of the image forming portion quickly, a sufficient time can be taken for registration of the paper S.

  Further, according to the paper feeding device 1, the paper S is transported without being bent in the transport direction, and the paper S is not bent in the transport direction, so that it is possible to prevent the paper S from being obliquely transported and transport jammed. it can. In addition, the first sheet S corresponding to the print request is fed from the sheet feed unit 1a closest to the main body 100 among the sheet feed units 1a and 1c storing the sheet S having a size corresponding to the print request. The distance from the paper supply unit to the main body 100 is the shortest, and the time from when a print request is made until the paper S reaches the main body 100 can be kept short (see method U6 shown in FIG. 4). The second and subsequent sheets S corresponding to the print request are sheet supply units other than the sheet supply unit 1a closest to the main body 100 among the sheet supply units 1a and 1c that store the sheet S of the size corresponding to the print request. Since the paper is fed from 1c, the consumption of the paper S stored in the paper feeding unit 1a closest to the main body 100 out of the paper feeding units 1a and 1c that store the paper S of the size according to the print request is suppressed. Cutting can be suppressed, and the time from when a print request is made until the first sheet S reaches the main body 100 can be reduced over a long period of time.

  Here, in a configuration in which a plurality of paper feeding devices are arranged in parallel on the side of the main body 100, a case where each paper feeding unit constituting the paper feeding device has a unique conveyance path will be considered.

  In the paper feeding device 200 shown in FIG. 6, the paper S is transported from the paper feeding units 201, 202, and 203 to the main body 100 via the transport paths H1, H2, and H3, respectively. In the sheet feeder 300 shown in FIG. 7, the sheet S is conveyed from the sheet feed unit 301 to the main body 100 via the conveyance path J1, and from the sheet supply unit 302 via the conveyance path J2 and the conveyance path J1. The sheet S is conveyed to the main body 100, and further, the sheet S is conveyed from the paper supply unit 303 to the main body 100 via the conveyance path J3, the conveyance path J2, and the conveyance path J1.

  When each of the paper feeding units as described above has an individual conveyance path for the sheet S to the main body 100, the shapes of the conveyance paths H <b> 1 to H <b> 3 and J <b> 1 to J <b> 3 differ depending on the position with respect to the main body 100. The order in which the paper units are arranged is fixed, and the compatibility of the paper feeding units becomes poor.

  On the other hand, according to the sheet feeding device 1 of the present invention, the sheet feeding units 1a to 1c are formed in substantially the same shape, so that the compatibility between the sheet feeding units 1a to 1c is high and the position relative to the main body 100 is high. The order of is not fixed. Further, since the paper feeding units 1a to 1c are formed in substantially the same shape, the workability of manufacturing the paper feeding units 1a to 1c can be improved and the cost can be reduced.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows the structure of the paper feed unit shown in FIG. FIG. 2 is a block diagram illustrating a schematic configuration of the image forming apparatus illustrated in FIG. 1. 6 is a diagram illustrating an example of a paper feeding method when paper S of the same size corresponding to a print request is stored in the paper feeding unit W, the paper feeding unit X, and the paper feeding unit Z. FIG. 5 is a timing chart in the case of a method U3 shown in FIG. It is a figure which shows the structure of a comparative example. It is a figure which shows the structure of another comparative example. FIG. 6 is a diagram illustrating an example of a conventional paper feeding method when sheets of the same size are stored in a paper feeding unit, a paper feeding unit, and a paper feeding unit. FIG. 9 is a timing chart in the case of a method V1 shown in FIG. 10 is a timing chart in the case of method V3 shown in FIG.

Explanation of symbols

A Image forming apparatus 1 Paper feeding device 1a, 1b, 1c Paper feeding unit 2 Mounting plate 3 Pickup roller 6 Carrying roller 8, 9 Paper guide 100 Main body R Carriage path S Paper W, X, Y, Z Paper feeding unit

Claims (9)

An image forming unit that forms an image based on image information on a sheet body in response to a print request;
In an image forming apparatus comprising: a plurality of sheet feeding units each storing sheet bodies of the same size to be supplied to the image forming unit,
The first sheet body corresponding to the print request is fed from the paper feeding section closest to the image forming section, and the second and subsequent sheet bodies corresponding to the print request are fed closest to the image forming section. An image forming apparatus that feeds paper from a paper feed unit other than a paper unit. A main body including at least one paper feeding unit among the image forming unit and the plurality of paper feeding units;
The sheet body is configured to be freely arranged in parallel to a side of the main body, and the sheet body is moved from the sheet feeding section to the main body according to the print request in response to another sheet feeding section among the plurality of sheet feeding sections. A plurality of paper feed units each having a conveyance path that conveys in the conveyance direction toward the image forming unit,
The first sheet body corresponding to the printing request is fed from the sheet feeding unit of the main body, and the second and subsequent sheet bodies corresponding to the printing request are selected from any of the plurality of sheet feeding units. Paper from the paper feed unit of
A sheet body fed from the sheet feeding unit is provided in a conveyance path provided in the sheet feeding unit in which the sheet body is accommodated, and in a sheet feeding unit disposed downstream of the sheet feeding unit in the conveyance direction. The image forming apparatus according to claim 1, wherein the image forming apparatus conveys the image to the image forming unit of the main body via the conveyed path.   When a next print request is made before the operation of the image forming unit relating to the sheet body supplied in response to the print request is completed, the plurality of first sheet bodies corresponding to the next print request are included in the plurality of sheets. The image forming apparatus according to claim 2, wherein paper is fed from any one of the paper feeding units.   3. The second and subsequent sheets are fed at a timing to be supplied to the image forming unit in accordance with an image forming interval on the sheet in the image forming unit. The image forming apparatus according to 3.   5. The second and subsequent sheet bodies are fed from a sheet feeding unit other than the sheet feeding unit closest to the image forming unit among the plurality of sheet feeding units. Image forming apparatus.   The image forming apparatus according to claim 2, wherein a conveying speed of the sheet member in a conveying path provided in the sheet feeding unit is higher than an image forming speed in the image forming unit. apparatus. A plurality of paper feed units each having a transport path for storing a sheet body to be supplied to the main apparatus in a paper feed section and transporting the sheet body in a transport direction from the paper feed section toward the main apparatus in response to a print request. In a paper feeding device comprising:
The plurality of paper feeding units are configured to be freely arranged in parallel,
The first sheet body corresponding to the print request is fed from the paper feed unit closest to the main apparatus among the paper feed units storing the sheet body of the size corresponding to the print request, and the print request is met. The second and subsequent sheet bodies are fed from a sheet feeding unit other than the sheet feeding unit closest to the main apparatus among the sheet feeding units storing the sheet bodies of a size corresponding to the print request,
Conveying the fed sheet body to a conveyance path provided in a paper supply unit in which the sheet body is accommodated and a paper supply unit disposed downstream of the paper supply unit in the conveyance direction A sheet feeding device that conveys the main device via a path.   When the next print request is made before the operation of the main apparatus relating to the sheet body supplied in response to the print request is completed, the first sheet body corresponding to the next print request is transferred to the next print request. The sheet feeding device according to claim 7, wherein sheets are fed from a sheet feeding unit other than a sheet feeding unit closest to the main unit among sheet feeding units storing a sheet body having a size according to a request. In a paper feeding method for feeding the sheet body in response to a print request from a plurality of paper feeding sections each containing a sheet body of the same size and transporting it to the image forming section,
The first sheet body corresponding to the print request is fed from the paper feeding section closest to the image forming section, and the second and subsequent sheet bodies corresponding to the print request are fed closest to the image forming section. A paper feeding method characterized in that paper is fed from a paper feeding unit other than the paper unit.

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