JP2007171379A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which can eliminate waste paper when printing on a roll paper and prevent the productivity from falling. <P>SOLUTION: This image forming device 10 has a transfer section 14 to carry roll paper P, image forming sections 16 provided along the transfer section 14, and buffer sections 30 provided between the image sections 16 to make the roll paper P length integral multiple times the page size of the roll paper P between the image forming sections 16. It synchronizes the printing end timing or start timing in the image forming sections 16 within the range not exceeding the roll paper P length adjusted in the buffer sections 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to a continuous paper printer that records images on continuous paper.

  In recent years, colorization of printed materials such as newspapers and advertisement flyers has become natural. Most of these are printed on a rotary press for mass printing, but advertising flyers should be developed in a pinpoint manner, taking into account regional characteristics, industry types, and the characteristics of products targeted for advertising. However, it is effective from the viewpoint of advertising efficiency and environment. For this reason, an electrophotographic high-speed color continuous paper printer or the like is more advantageous than a rotary press that prints many types of documents in a relatively small amount.

  High-speed color continuous paper printers that print images on continuous paper in an electrophotographic manner have been widely used in recent years because they can print many sheets in a short time. This continuous paper printer has yellow (Y), magenta (M), cyan (C), and black (K) image forming units, and each image forming unit has a photosensitive drum rotating at a constant speed. In addition to forming a toner image, conveying the continuous paper according to the transfer timing of the toner image, and transferring and fixing the toner image from the photosensitive drum to the continuous paper, the image is printed. (For example, refer to Patent Document 1).

  As described above, the current high-speed color continuous paper printer is provided with a plurality of image forming units, and mainly employs a method of transferring multiple colors. However, in such a continuous paper printer, if the printer is stopped in the middle of the printing operation, all of the plurality of image forming units are stopped after completing the transfer of the image data (after full color printing). Therefore, there is a problem that waste paper corresponding to the distance from the first image forming unit to the final image forming unit is generated every time the printer is restarted (printing is resumed).

In addition, each image forming unit prints intermittently even when the processing speed for developing an image with a large amount of data or an image composed of complex logic on the image memory is inferior to the transport speed for transporting continuous paper. Since the operation is repeated, waste paper is generated each time. As a method of preventing the generation of such waste paper, after fixing a page on which full color printing (transfer) has been completed, the start of the next page that has not been printed is set to the transfer start position of the first image forming unit. However, this causes a problem that the printing performance (productivity) is remarkably lowered.
Japanese Patent Laid-Open No. 5-42693

  In view of the above problems, an object of the present invention is to obtain an image forming apparatus capable of preventing the generation of waste paper and preventing the reduction of productivity in the printing of continuous paper.

  In order to achieve the above object, an image forming apparatus according to claim 1 of the present invention includes a transport unit that transports continuous paper, and a plurality of image forming units provided along the transport unit. A buffer unit that is provided between the plurality of image forming units and adjusts the length of the continuous paper existing between the image forming units so as to be an integral multiple of the page size of the continuous paper. And the printing operation completion timings or printing operation start timings of the plurality of image forming units are synchronized within a range not exceeding the length of the continuous paper adjusted by the buffer unit.

  According to the first aspect of the present invention, when the image forming apparatus is stopped during the printing operation, the conveying operation can be stopped almost simultaneously with the stop instruction. That is, the continuous paper existing between the image forming units is always set to a length (an integer multiple of the page size) defined by the buffer unit based on the page size. If the printing of the page that is being printed at the completion of the printing is completed, it is possible to stop the continuous paper transporting operation.

  For this reason, when the image forming apparatus is restarted and printing is resumed, printing from the next page is always possible. Therefore, it is necessary to control the conveyance operation to stop after full-color printing is completed as in the past. And not. Accordingly, there is no waste paper corresponding to the distance from the first image forming unit to the final image forming unit. In addition, as a result, it is not necessary to back-feed the unprinted next page up to the first image forming unit as in the prior art, so that it is possible to prevent a decrease in printing performance (a decrease in productivity).

  The image forming apparatus according to claim 2 is characterized in that, in the image forming apparatus according to claim 1, the buffer unit is configured to be position-adjustable in accordance with a change in page size. .

  According to the second aspect of the present invention, even if the page size of the continuous paper is different, it can be flexibly dealt with.

  According to a third aspect of the present invention, there is provided the image forming apparatus according to the first or second aspect, wherein the continuous paper transporting operation is stopped during the printing operation by the plurality of image forming units. Further, the image data at the time of the printing operation is held until it is completely transferred to the continuous paper.

  According to the third aspect of the present invention, when the printing operation is resumed, it is possible to continue printing. Therefore, generation of waste paper can be further prevented.

  As described above, according to the present invention, it is possible to provide an image forming apparatus capable of preventing the generation of waste paper and preventing the decrease in productivity in the printing of continuous paper.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail based on the embodiments shown in the drawings. The image forming apparatus according to the present invention is an electrophotographic high-speed color continuous paper printer 10 that records images on continuous paper P, and its schematic configuration is shown in FIGS. In the figure, the direction of arrow A is the transport direction and the direction of arrow B is the upward direction.

  As shown in FIGS. 1 and 2, the continuous paper printer 10 includes a paper feeding unit 12 that feeds web-like continuous paper P, a transport unit 14 that transports the continuous paper P, and the continuous paper. A plurality of papers which are arranged (transferred) on the continuous paper P which is arranged at a predetermined interval (from the upstream side to the downstream side) along the P conveyance direction (arrow A direction) Four image forming units 16Y, 16M, 16C, and 16K of yellow (Y), magenta (M), cyan (C), and black (K) and the transferred full-color toner image are fixed on the continuous paper P. And a fixing unit 18.

  The paper feeding unit 12 includes a paper feeding device 20 that rotatably holds an axial center around which the continuous paper P is wound, and sequentially feeds the continuous paper P to the image forming units 16Y to 16K. It is configured. The conveyance unit 14 guides the continuous paper P from the paper supply unit 12 to the first image forming unit 16Y and guides the continuous paper P from the final image forming unit 16K to the fixing unit 18. And a roller 24.

  Further, the transport unit 14 transfers the continuous paper P to the transfer units 36Y to 36K (described later) of the image forming units 16Y to 16K in synchronization with the writing (transfer start) timing by the photosensitive drums 32Y to 32K (described later). It includes registration rollers 26Y to 26K for guiding (conveying), and discharge guide rollers 28Y to 28K for guiding (conveying) the continuous paper P transferred by the transfer units 36Y to 36K to the next process. 28K and discharge guide rollers 28Y to 28K are provided in pairs for each of the image forming units 16Y to 16K.

  The image forming units 16Y to 16K are respectively connected to photosensitive drums 32Y to 32K rotating in the direction of arrow D, exposure units 34Y to 34K having a laser exposure device (not shown), and developing units 35Y to 35K having a development device (not shown). Transfer sections 36Y to 36K for transferring toner images developed on the photosensitive drums 32Y to 32K to the continuous paper P are disposed opposite to the photosensitive drums 32Y to 32K across the conveyance path of the book paper P. ing.

  The transfer units 36Y to 36K are provided with transfer guide rollers (not shown) that rotate following the photosensitive drums 32Y to 32K, respectively. The transfer guide rollers transfer the continuous paper P to the surfaces of the photosensitive drums 32Y to 32K. The toner images formed on the surfaces of the photosensitive drums 32Y to 32K are transferred onto the continuous paper P.

  Further, the transfer portions 36Y to 36K are structured so as to be detachable from the photosensitive drums 32Y to 32K. That is, the transfer guide rollers provided in the transfer units 36Y to 36K approach so that the continuous paper P is in close contact with the photosensitive drums 32Y to 32K during the transfer, and when the continuous paper P transport operation is stopped, The continuous paper P is separated so as not to contact the photosensitive drum 32. This prevents inadvertent contamination of the continuous paper P.

  Further, there is a variation in the page size of the continuous paper P between the image forming unit 16Y and the image forming unit 16M, between the image forming unit 16M and the image forming unit 16C, and between the image forming unit 16C and the image forming unit 16K. Accordingly, buffer rollers 30 configured to be movable up and down are provided. The three buffer rollers 30 are configured to be movable up and down independently or synchronously by a conventionally known means.

  Further, the printing operation completion timing (or printing operation start timing) of each of the image forming units 16Y to 16K is configured to be synchronized within a range not exceeding the length of the continuous paper P adjusted by the buffer roller 30. That is, when the continuous paper printer 10 is stopped in the middle of the printing operation, after each of the image forming units 16Y to 16K prints the page currently printed (transferred) (delimited by the dotted line T in FIG. 3). When the trailing edge (leading edge of the next page) T of the page coincides with the transfer start position, the conveyance operation of the continuous paper P is stopped.

  The fixing unit 18 includes a flash fixing device 38 that flash-fixes the toner image transferred to the continuous paper P. The fixing unit 18 fixes the toner image transferred to the continuous paper P in a non-contact manner on the continuous paper P. A post-processing device unit (not shown) is provided on the downstream side of the fixing unit 18.

  The continuous paper printer 10 is provided with a control unit (not shown) for controlling each unit, and the image data is temporarily held by the control unit and input to the image forming units 16Y to 16K. . In other words, even if the continuous paper P transport operation is stopped during the printing operation by each of the image forming units 16Y to 16K, the continuous paper printer 10 transfers the image data being printed (transferred) to the continuous paper. Until the transfer to P is completed, it is held by the control unit.

  Next, the operation of the continuous paper printer 10 having the above configuration will be described. When an instruction to execute printing is given, the control unit controls the paper feeding unit 12 and the conveyance unit 14 to apply a predetermined tension to the continuous paper P and perform a predetermined amount along the conveyance direction (arrow A direction). The continuous paper P is transported at the transport speed.

  At the same time, image data is input from the control unit to each of the image forming units 16Y to 16K. When the image data is input to each of the image forming units 16Y to 16K, each of the image forming units 16Y to 16K irradiates the photosensitive drums 32Y to 32K with a laser beam by a laser exposure device (exposure units 34Y to 34K). The surface is exposed to form a latent image corresponding to the image data.

  Then, the developing device (developing units 35Y to 35K) attaches toner to the latent images formed on the surfaces of the photosensitive drums 32Y to 32K, and forms a toner image on the surface. The toner images formed on the surfaces of the photosensitive drums 32Y to 32K are transferred to the continuous paper P by transfer guide rollers (transfer units 36Y to 36K).

  That is, when the continuous paper P passes through the image forming unit 16Y, the image forming unit 16M, the image forming unit 16C, and the image forming unit 16K in this order, the toner images formed on the surfaces of the photosensitive drums 32Y to 32K are formed. Then, yellow (Y), magenta (M), cyan (C), and black (K) are overlaid in this order by the transfer guide rollers of the transfer portions 36Y to 36K. As a result, a full-color toner image is formed on the continuous paper P.

  Thus, the continuous paper P on which the full-color toner image is formed (transferred) is conveyed to the fixing unit 18, and the toner image is fixed by the flash fixing device 38. Then, after the toner image is fixed, it is further conveyed to a post-processing device (not shown).

  Here, the continuous paper P transported to the image forming units 16Y to 16K is page size (length in the transport direction, dotted line) by the buffer roller 30 disposed between the image forming units 16Y to 16K. The buffer amount is adjusted so as to be an integral multiple of (interval divided by T).

  More specifically, FIG. 3 shows continuous paper P having different page sizes. The continuous paper P shown in FIG. 3A is a continuous paper P having a page size of, for example, 14 inches, and the continuous paper P shown in FIG. 3B has a page size of, for example, 11 inches. It is the continuous paper P which is said.

  As shown in FIG. 3, the image forming unit 16M (photosensitive drum 32M) and the image forming unit 16C (photosensitive) within a distance L1 between the image forming unit 16Y (photosensitive drum 32Y) and the image forming unit 16M (photosensitive drum 32M). The length (buffer amount) of the continuous paper P to be present within the distance L2 between the drums 32C) and within the distance L3 between the image forming unit 16C (photosensitive drum 32C) and the image forming unit 16K (photosensitive drum 32K). ) Is adjusted so that the position of the buffer roller 30 in the vertical direction is an integral multiple of the page size (two in the figure).

  The printing operation completion timing (or printing operation start timing) of each of the image forming units 16Y to 16K is the length (buffer amount) of the continuous paper P adjusted by the buffer roller 30, that is, in this case, for two pages. It is set as the structure synchronized within the range which does not exceed length. That is, when an instruction is given to stop the continuous paper printer 10 during the printing operation, when the trailing edge (leading edge of the next page) T of the page being printed coincides with the transfer start position, The conveyance operation of the continuous paper P is stopped.

  Therefore, even if the continuous paper printer 10 is stopped during the printing operation by each of the image forming units 16Y to 16K, the transport operation of the continuous paper P can be stopped almost simultaneously with the instruction. That is, the continuous paper P existing between the image forming units 16Y to 16K is always set to a length (an integer multiple of the page size) defined by the buffer roller 30 on the basis of the page size. If printing of the page that is being printed when the stop of the book printer 10 is instructed, the transport operation of the continuous paper P can be stopped.

  For this reason, when the continuous paper printer 10 is restarted and printing is resumed, the image forming units 16Y to 16K can always perform printing (transfer) from the top of the next page. There is no need for control to stop the conveying operation after the printing at the end. Therefore, there is no waste paper corresponding to the distance from the first image forming unit 16Y to the final image forming unit 16K.

  This also prevents a decrease in print throughput performance (a decrease in productivity due to backfeeding the unprinted next page tip T to be printed to the transfer start position of the first image forming unit 16Y). It is also possible to prevent a decrease in printing performance (a decrease in productivity) during intermittent printing or printing of a plurality of jobs.

  Further, when the continuous paper P transport operation is stopped during the printing operation by the image forming units 16Y to 16K, the continuous paper printer 10 transfers the image data being printed (transferred) to the continuous paper P. Until the transfer is completely completed, the control unit holds it. Therefore, when the printing operation (conveying operation) is resumed, it is possible to continue printing, thereby further preventing the generation of waste paper.

Schematic side view showing a part of the configuration of the continuous paper printer Schematic side view showing a part of the configuration of the continuous paper printer Schematic perspective view showing the length of continuous paper defined by the buffer roller

Explanation of symbols

10 Continuous paper printer (image forming device)
DESCRIPTION OF SYMBOLS 12 Paper feed part 14 Conveyance part 16 Image formation part 18 Fixing part 20 Paper feed device 21, 22, 24 Guide roller 26 Registration roller 28 Discharge guide roller 30 Buffer roller (buffer part)
32 Photosensitive drum 34 Exposure unit 35 Development unit 36 Transfer unit 38 Flash fixing device P Continuous paper

Claims (3)

A transport unit for transporting continuous paper;
A plurality of image forming units provided along the conveying unit;
A buffer unit that is provided between the plurality of image forming units and adjusts the length of the continuous paper existing between the image forming units to be an integral multiple of the page size of the continuous paper;
With
An image forming apparatus having a configuration in which printing operation completion timings or printing operation start timings of the plurality of image forming units are synchronized within a range not exceeding the length of the continuous paper adjusted by the buffer unit. .   The image forming apparatus according to claim 1, wherein the buffer unit is configured to be position-adjustable according to a change in page size.   When the transport operation of the continuous paper is stopped during the printing operation by the plurality of image forming units, the image data at the time of the printing operation is held until the transfer to the continuous paper is completed. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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