JP4099963B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus including a plurality of paper feed trays.
[0002]
[Prior art]
A copy having a plurality of paper feed trays and configured to continuously supply the transfer material to the image transfer unit while switching the paper feed trays according to the preset order of the paper feed trays, and to perform image transfer. Image forming apparatuses such as printers and printers are well known.
[0003]
At this time, the transfer material is supplied from the paper feed unit of the paper feed tray in the order in which the image is transferred by the image transfer unit.
[0004]
That is, as shown in the schematic diagram of FIG. 2, the transfer materials P1, P2, and P3 are transferred in the order of the transfer materials P1 → P2 → P3 on the photosensitive drum 401 constituting the image forming unit.
[0005]
The transfer material feeding order from the paper feed tray corresponding to this is as an example in FIG. 3 where the transfer material P2 is fed from the paper feed tray 511 and the transfer material P3 is fed from the paper feed tray 531. This will be described with reference to a schematic diagram.
[0006]
That is, the transfer material P2 stored in the paper feed tray 511 with respect to the transfer material P1 fed from the paper feed tray and transported to the photosensitive drum 401 has a rear end in the transport direction of the transfer material P1 and the transfer material P2. The paper is fed from the paper feed tray 511 when the interval from the leading edge in the transport direction is a time interval corresponding to a preset interval.
[0007]
Similarly, the transfer material P3 is fed from the paper feed tray 531 at a time interval with respect to the transfer material P3.
[0008]
However, if the paper feed tray in which the transfer material P3 is stored is the same paper feed tray 511 as the transfer material P2, the transfer interval between the transfer materials P2 and P3 is equal to the time interval, and there is no time waste. As shown in FIG. 1, if the paper feed tray 511 and the paper feed tray 531 are separated from each other, the transport time corresponding to the transport distance between them becomes a waste time in continuous processing.
[0009]
The dead time is similarly generated between the paper feed tray 521, the paper feed tray 541, and the re-transport unit 9 (ADU) shown in FIG.
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and its main purpose is to eliminate waste of transfer material conveyance time and to shorten time to image transfer.
[0011]
[Means for Solving the Problems]
The object of the present invention can be achieved by the following constitution.
[0014]
( 1 ) In an image forming apparatus that includes a plurality of paper feed trays and continuously supplies a transfer material to an image transfer unit while switching the paper feed trays according to a preset paper feed order, and performs image transfer. The transfer material starting from the paper supply tray is switched with respect to the preset paper supply order, and the transfer unit is placed at the tip of the paper supply from the succeeding paper supply tray. When there is no transfer material supplied to the printer or when an image cannot be transferred due to a jam, control means for controlling the transfer material, which has started feeding from the preceding paper feed tray, to stop and wait in the paper feed path An image forming apparatus comprising:
[0015]
( 2 ) In an image forming apparatus that includes a plurality of paper feed trays, continuously supplies a transfer material to an image transfer unit while switching the paper feed trays according to a preset paper feed order, and performs image transfer. The transfer material starting from the paper supply tray is switched with respect to the preset paper supply order, and the transfer unit is placed at the tip of the paper supply from the succeeding paper supply tray. If there is no transfer material supplied to the printer, or if an image cannot be transferred due to a jam, control is performed so that the transfer material that has started feeding from the preceding paper feed tray is output as a blank sheet and the operator is notified of this. An image forming apparatus comprising: means.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment according to the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus (hereinafter also referred to as a copying machine) when viewed from the front.
[0018]
The copying machine of the present embodiment is provided with an automatic document feeder ADF at the top of the copying machine main body, and an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, and a transfer in the copying machine body. A material storage unit 5, a transfer material conveyance belt unit 6, a fixing unit 7, a paper discharge / switching unit 8, and a reconveying unit (ADU) 9 are provided.
[0019]
The automatic document feeder ADF is a device that feeds documents d one by one, conveys them to the image reading position, and discharges the document after the image reading to a predetermined place.
[0020]
In the image reading unit 1, reading of image information from the document d passing through the image reading position by the ADF or the document d placed on the platen glass 101 on the document table is performed using a movable exposure lamp and a first mirror. Are reflected by a first mirror unit 102 including a second mirror unit 103 including a second mirror and a third mirror, and are imaged on a line-shaped image sensor (hereinafter referred to as a CCD) 105 via an imaging lens 104. Is done.
[0021]
The line-shaped optical image formed on the CCD 105 is sequentially converted into an electric signal (luminance signal), A / D converted, and subjected to processing such as density conversion and filter processing in the image processing unit 2. The image data is temporarily stored in the memory.
[0022]
On the other hand, in the image forming unit 4, an image transfer unit 402 that transfers a charged image formed on the photosensitive drum 401 that is an image carrier to a transfer material, and a separation electrode 403 that separates a transfer material that is in close contact with the photosensitive drum 401. The transfer material conveying belt unit 6 serving as a conveying unit, the cleaning unit 407 of the photosensitive drum 401, and the precharge lamp (PCL) 406 serving as a light neutralizing unit are arranged in the order of operation.
[0023]
When the photosensitive member drive motor (not shown) is started, the photosensitive drum 401 rotates counterclockwise, and a potential is applied to the photosensitive drum 401 by the charging action of the scorotron charger 404.
[0024]
Thereafter, the exposure optical system 3 serving as an image exposure unit serving as a writing unit uses a laser diode (not shown) as a light emission source, passes through a rotating polygon mirror 301, and passes through reflection mirrors 302 and 303 to the photosensitive drum 401. The image exposure in the main operation direction is performed at the position A indicated by the arrow based on the image signal called from the memory of the image processing unit 2, and the photosensitive drum 401 is subjected to sub-scanning by the rotation of the photosensitive drum 401. A latent image is formed on the top.
[0025]
Subsequently, the latent image formed on the photosensitive drum 401 is reversely developed by the developing unit 408, and a visible toner image is formed on the surface of the photosensitive drum 401.
[0026]
On the other hand, in the transfer material storage unit 5, paper feed trays 511, 521, 531, and 541 are provided as transfer material storage units 5 in which transfer materials P of different sizes, the same sizes, or materials are stored below the image forming unit 4. Is provided.
[0027]
The transfer material P stored in the paper feed tray 511 (521, 531, 541) selected based on the memory input in advance is sent out by the paper feed rollers 512 (522, 532, 542), and the separation rollers 513 (523, 523, 542). 533, 543), and the sheet feeding state is checked by the transfer material detection sensor S1 (S2, S3, S4).
[0028]
Next, the paper is transported in the transport path 550 by a guide roller selected from R 1 to R 7, temporarily stopped by the registration roller pair 501, and then fed again by the rotation of the registration roller pair 501, and guided to the image transfer unit 402. Is done.
[0029]
On the other hand, the toner image on the photosensitive drum 401 is transferred onto the transfer material P via the image transfer unit 402 at the transfer position B (position indicated by the arrow).
[0030]
Next, the transfer material P is separated from the surface of the photosensitive drum 401 by the action of the separation unit 403 and then conveyed toward the fixing unit 7 by the transfer material conveyance belt 6.
[0031]
The fixing unit 7 includes a fixing roller 701 and a pressure roller 702. When the transfer material P passes between the fixing roller 701 and the pressure roller 702, the fixing unit 7 is heated and pressed. The toner image is melted and fixed on the transfer material P.
[0032]
Further, the transfer material P on which the toner image is fixed is conveyed by a fixing discharge roller 703 and a discharge roller 801 and discharged onto a discharge tray 802.
[0033]
On the other hand, the photosensitive drum 401 from which the transfer material P has been separated is neutralized by the separation pole 403, and then the toner remaining on the peripheral surface of the photosensitive drum 401 is rubbed by the cleaning blade 405. By cleaning, the history is canceled and preparation for the next image formation is made.
[0034]
Next, embodiments of control by the control means according to the present invention will be described below.
[0035]
As shown in FIG. 1, in a copier equipped with the four paper feed trays 511, 521, 531, 541 that store the transfer material P, a paper feed tray 511 that supplies the transfer material P to the image transfer unit 402, The order of 521, 531, 541 is input in advance from the key switch of the operation unit, stored in the memory, and set.
[0036]
The control means controls the paper feed trays 511, 521, 531 and 541 to be set in the memory and to switch the paper feed trays according to the order, so that the transfer material P is continuously supplied to the image transfer unit 402. It has become.
[0037]
Here, one embodiment of the present invention will be described based on the following examples.
A so-called intersheet function that inserts an intersheet (color sheet, etc.), which is one form of transfer material, at an arbitrary page position of a plurality of transfer material copies is generally adopted as one special function of a copying machine. Yes.
[0038]
In FIG. 1, the transfer material P3 (shown in FIG. 3) previously laminated on the paper feed tray 531 is stored, and the intersheet which is one form of the transfer material is stored in the paper feed tray 511. The above copy can be executed.
[0039]
That is, when an application function button is selected and pressed in a key operated mode in an operation unit having a liquid crystal touch panel, an application function selection screen is displayed on the liquid crystal touch panel.
[0040]
When the inter sheet mode displayed on the application function selection screen is selected and the OK key is pressed, a page setting screen is displayed on the display.
[0041]
The page position for inserting the inter sheet (color sheet or the like) is set with the display key and the number setting button, and the setting key is pressed to confirm the page, and the setting for switching to the paper feed tray 511 for storing the inter sheet is set. Is done.
[0042]
By repeating the above, specifying a necessary page and pressing the OK key, the order of switching to the intersheet function and the paper feed tray 511 is set.
[0043]
In this way, the setting of the order of supplying the transfer material P or P3 from the paper feed tray 511 or 531 to the image transfer unit 402 is stored in advance in the memory by the key input in the operation unit described above, and is set in the memory. By controlling the control means to switch the paper feed tray in accordance with the order, the transfer material P or P3 is continuously supplied to the image transfer unit 402.
[0044]
At this time, as the paper feed tray is switched, which of the two paper feed trays 511 or 531 before and after the switching is longer with respect to the length of the paper feed path from the paper feed tray to the image transfer unit 402. Since it is known in advance, the order of starting the feeding of the transfer material P or P3 is switched by setting in advance a program for controlling to feed paper from the paper feed tray 531 having a long paper feed path first. Whether or not can be controlled.
[0045]
Next, the sheet feeding of the transfer material P3 from the sheet feeding tray 531 is started continuously, and the intersheet function and sheet feeding tray switching control based on the order set in the memory are schematically shown in FIG. This will be described with reference to the drawings.
[0046]
Switching from the paper feed tray 531 to the paper feed tray 511 is controlled in accordance with the order set in the memory. At this time, the image transfer unit 402 (see FIG. 1) disposed from the paper feed tray 511 to the photosensitive drum 401 is controlled. And the length of the paper feed path from the paper feed tray 531 to the image transfer unit 402 are compared.
[0047]
Next, since the length of the paper feed path from each paper feed tray is known in advance, if it is determined that the paper feed path from the paper feed tray 531 to the image transfer unit 402 is longer, it is input in advance. The order of starting the sheet feeding from the sheet feeding tray is switched, and the sheet feeding from the sheet feeding tray 511 is started instead of starting the sheet feeding from the sheet feeding tray 531 in advance. Be controlled.
[0048]
In this manner, by starting the feeding of the transfer material from the paper feed tray in an order different from the order in which the images are transferred, the influence of the difference in the arrangement of the paper feed trays is eliminated. It is possible to eliminate waste of transport time.
[0049]
On the other hand, the transfer material (intersheet) P2 accommodated in the paper feed tray 511 includes the rear end in the feed direction of the transfer material P1 fed to the previous image transfer unit 402 and the transfer material (intersheet) P2. When the distance from the leading end in the feeding direction reaches a preset distance, the sheet feeding is started from the sheet feeding roller 512 of the sheet feeding unit of the sheet feeding tray 511 following the transfer material P3.
[0050]
The transfer material P3 transported in advance is temporarily stopped and put on standby at a point T1 immediately before the transfer path of the transfer material (intersheet) P2 and the transfer path of the transfer material P3 merge.
[0051]
Next, when the distance between the trailing edge of the transfer material (intersheet) P2 in the conveyance direction and the leading edge of the transfer material P3 in the conveyance direction reaches a preset distance, the transfer material P3 stops at the point T1 of the paper feed path and waits. Feeding of the transferred transfer material P3 is resumed by the feed roller 532 of the feed tray 531.
[0052]
Thereafter, the transfer material P3 stored in the tray 531 is continuously fed by the paper feed roller 532, and the transfer material (intersheet) P2 stored in the paper feed tray 511 is fed by the paper feed roller 512. The next control signal is sent out from the control means, and the same order and timing of paper feeding and conveyance as described above are repeated.
[0053]
As described above, the feeding interval between transfer materials to which images are transferred continuously is not affected by the length of the feeding path due to the difference in the arrangement of the feeding trays, and the feeding at the minimum feeding interval is always performed. Paper can be used, and waste time due to paper feeding can be saved, and the time until image transfer can be shortened.
[0054]
During the continuous operation, in the feeding of the transfer material (intersheet) P2 stored in the paper feed tray 511, paper feed is started by the paper feed roller 512 of the paper feed tray 511, and one sheet is conveyed by the separation roller 513. If the transfer material P2 is not detected even if the time to reach the transfer material detection sensor S1 elapses in advance, it is determined that there is no transfer material or a jam, and a trouble is displayed on the operation unit of the copying machine. And the function of the copier is controlled to stop.
[0055]
At this time, the transfer material P3 is started to be fed from the paper feed roller 532 of the paper feed tray 531 prior to the start of feeding the transfer material P2 from the paper feed roller 512 of the paper feed tray 511. The transfer material P3 is in a stopped / standby state at the point T1, or is in a conveying state in the middle of the paper feed path upstream from the point T1, and the transfer material P3 is moved at this point as the copying machine stops functioning. Stop.
[0056]
Next, the cause of the trouble is removed from the paper feed tray 511 determined to have no transfer material or jammed, the current state is restored, the trouble display on the operation unit of the copier disappears, and the copier is restarted. If it does, it will control so that a function may be started from the process just before a trouble mentioned above.
[0057]
As a result, the order of transfer material output is not upset and can be handled without waste.
In addition, when the above jam occurs, the transfer material P3 that has started feeding from the paper feed tray 531 remains in the middle of the paper feed path 550, and at the time of restart, the transfer material P3 and the next transfer material are fed. There is a possibility that the control of paper feeding becomes complicated and the order of pages of the output transfer material may be out of order. As another method for preventing this, the transfer material P3 from the paper feed tray 531 is automatically output as one blank sheet. Then, there is a control method in which a display to that effect is displayed on the operation unit of the copying machine to notify the operator.
[0058]
Based on this, the operator can remove the blank sheet output to the paper discharge tray 802 and transfer the image of the page corresponding to the blank sheet output at the time of restart to prevent the page from shifting.
[0059]
The above has been described in the embodiment between the paper feed tray 531 and the paper feed tray 511, but the same can be applied to combinations with other paper feed trays 521 and 541.
[0060]
For example, in the case of the combination of the paper feed tray 531 and the paper feed tray 521, the position where the transfer material P3 stored in the paper feed tray 531 temporarily stops in the paper feed path and the standby position is as shown in FIG. This is a point T2 immediately before the feeding path of P2 and the feeding path of the transfer material P3 merge.
[0061]
Also, the present invention can be applied to a combination with the above-mentioned 531 and 541 which are paper feed trays for large-volume processing (accommodating about 1000 sheets, 1500 sheets).
[0062]
Further, the present invention can be similarly implemented by combining the ADU 9 and the paper feed trays 511 (521, 531, 541) in FIG.
[0063]
That is, in a copying machine configured to continuously transfer images onto both sides of a transfer material using a double-sided copy function, an image is formed on the first side (or front side) of the transfer material, and then the transfer is performed. In order to transfer the image to the second surface side (or back side) of the material where the image has not yet been transferred, the transfer material is fed to the paper feed path of the ADU 9 and close to the upstream side of the final discharge roller pair R10 of the ADU 9 The transfer material detection sensor S5 arranged in this manner detects the leading edge of the preceding transfer material in the feeding direction.
[0064]
Next, when a time corresponding to a preset interval with the succeeding transfer material comes, the succeeding transfer material already waiting at the point T3 is preset with the preceding transfer material. The paper feeding is resumed while maintaining the interval.
[0065]
Further, the sheet feeding trays 511, 521, 531, 541 for guiding the transfer material to the common sheet feeding path 550 constituted by the guide roller pairs R3, R4, R5, R6, and R7 and the joining portion from the sheet feeding path of the ADU 9 are viewed. Thus, in contrast to the case of the paper feed trays 531 and 541 in which the merging portion is disposed on the upstream side of the merging portion of the ADU 9, the paper feeding trays 511 and 521 in which the merging portion is disposed on the downstream side of the merging portion of the ADU 9 In this case, the distance between the rear end in the feed direction of the transfer material discharged from the final discharge roller pair R10 of the ADU 9 and the front end in the feed direction of the transfer material fed from the paper feed tray 511 (or 521) is. The transfer material P stacked and stored in the paper feed tray 511 (or 521) at a preset interval is fed from the paper feed roller 512 (or 522) to the paper feed path.
[0066]
In the present embodiment, the case where the ADU 9 is disposed between the upper and lower sides of a plurality of paper feed trays as shown in FIG. 1 has been described, but it is directly above the paper feed tray 511 and directly below the image forming unit 4. The above-described embodiment can be applied even in the case where it is disposed in the middle of the sheet feeding tray 531 (or 541) disposed in the lowermost part.
[0067]
The above description has been made in the case of the intersheet function. However, as another embodiment, a transfer material (for example, A4 size) mainly for image formation is stacked and stored in the paper feed tray 531, and has a different size from the transfer material. In some cases, transfer materials (for example, A3, B4 sizes, etc.) are stacked and stored in the paper feed trays 511 and 521, and the transfer materials of different sizes are sometimes inserted at arbitrary page positions in image formation of the transfer material. is there.
[0068]
Even in such a case, the above-described embodiment can be applied.
The image forming apparatus according to the present invention can be applied to all apparatuses equipped with a plurality of paper feed trays such as printers and facsimiles in addition to copying machines.
[0069]
【The invention's effect】
By starting the feeding of transfer material with priority from the paper feeding tray with the longer paper feeding path from the paper feeding tray to the image transfer unit, the paper feeding interval between the transfer materials to which images are transferred continuously is increased. It is possible to eliminate the influence of the difference in the arrangement position of the paper tray, to feed the paper at the minimum paper feeding interval, to save the waste time due to paper feeding, and to shorten the time until image transfer.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration when a copying machine according to an embodiment of the present invention is viewed from the front.
FIG. 2 is a schematic diagram illustrating a transfer order of transfer materials from a paper feed tray to a photosensitive drum of an image forming unit.
FIG. 3 is a schematic diagram showing a state in which a transfer material is fed from a conventional paper feed tray.
FIG. 4 is a schematic diagram illustrating a state in which a transfer material is fed from a paper feed tray according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image reading part 2 Image processing part 3 Image writing part 4 Image forming part 401 Photosensitive drum 402 Image transfer part 5 Transfer material storage part 511 Paper feed tray 512 Paper feed roller 513 Separation roller S1 Transfer material detection sensor 8 Paper discharge / switching Section 9 Re-transport section (ADU)
P (P1, P2, P3) Transfer material

Claims (2)

In an image forming apparatus that includes a plurality of paper feed trays and continuously supplies a transfer material to an image transfer unit while switching the paper feed trays according to a preset paper feed order, The order of the transfer material that starts feeding from the paper feed tray is switched with respect to the set paper feed order, and is fed from the succeeding paper feed tray to the transfer section at the end of the paper feed. If there is no transfer material to be transferred or if an image cannot be transferred due to a jam, the image forming apparatus has a control means for controlling the transfer material that has started feeding from the preceding paper feed tray to be stopped / standby in the paper feed path. An image forming apparatus. In an image forming apparatus that includes a plurality of paper feed trays and continuously supplies a transfer material to an image transfer unit while switching the paper feed trays according to a preset paper feed order, The order of the transfer material that starts feeding from the paper feed tray is switched with respect to the set paper feed order, and is fed from the succeeding paper feed tray to the transfer section at the end of the paper feed. If there is no transfer material to be transferred or if an image cannot be transferred due to a jam, a control means is provided for controlling the output of the transfer material that has started feeding from the preceding paper feed tray as a blank sheet and notifying the operator of that. An image forming apparatus.

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