JP2008068996A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing a continuous printing performance from being lowered by individually controlling the conveying of paper sheets even if the interval between the paper sheets is increased during the conveyance of the paper sheets. <P>SOLUTION: Paper sheets are conveyed for each of a first feed tray to a fifth feed tray with conveyor rollers 6 and conveyor sensors 5. To drive each of the rollers, each clutch is controlled by a CPU 7, and each roller is driven by each clutch. The front end of the preceding paper 1 fed from the first feed tray is detected by the conveyor sensor 5, and the rear end of the paper during the feeding is calculated from the timing of the detection. Depending on whether the interval between the paper and the preceding paper is large or not, the preceding paper 1 fed from the first feed tray is temporarily stopped, and the conveyance of the subsequent paper 2 fed from the fifth feed tray is continued to a predetermined position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that reduces a gap between sheets fed from different trays when sheets are continuously conveyed.

  A sheet feeding device in today's image forming apparatus has a configuration in which a plurality of sheet feeding trays exist. When a document is conveyed, sheets from the sheet feeding tray are fed one by one. When continuous printing is performed, the positional distance of the tray is always generated. In such a case, since the sheet interval is widened, there is a problem that the continuous printing performance originally possessed by the image forming apparatus cannot be exhibited.

  In order to increase the amount and number of copied paper produced by the image forming device and increase productivity, increase the operating speed in the device or shorten the interval between papers as much as possible. It is necessary to take measures such as reducing the image time. Increasing the operating speed of the device will accelerate the consumption of each part of the device, shorten the life of the device, and shorten the maintenance cycle. Or the operating noise of the device increases and the noise increases. These measures are costly, resulting in an increase in device costs. In order to shorten the sheet interval, it is necessary to strictly manage the feeding control for each sheet. The time for each sheet to reach the image transfer unit from the sheet feeding tray depends on the sheet type, sheet thickness, roller Due to the change over time, the performance of individual electrical parts, and the like, the conveyance conditions for each sheet are not stable, and therefore the time from the paper feed tray to the image transfer unit varies. In the conventional transport control method, the paper interval is set in accordance with the maximum delay time in consideration of the variation, and therefore, it is possible to reduce the interval only to the point where no problem occurs. Therefore, various developments have been performed conventionally. Next, the example is given.

  For example, in Patent Document 1, a casing, a sheet feeding tray that is linked to the casing, and a downstream edge of the sheet feeding tray are mounted on a collating machine that converges a plurality of newspaper advertisement sheets. A sheet feeding roll rotatably supported so as to communicate with the sheet feeding mechanism, a mechanism for separating the sheets stacked and loaded on the sheet feeding tray, and a lateral side for conveying the sheets separated by the mechanism. By having a transport roll, a paper feed roll drive motor and a lateral transport roll drive motor for driving the paper feed roll / lateral transport roll, and a control means for each motor, an external signal is obtained, A control device and a control method for a paper feeding device that enable start / stop and control of speed and acceleration are proposed.

In Patent Document 2, during continuous paper feeding, after paper is fed from the paper feeding device to the transport unit, the paper feed clutch is turned off, and the paper is being fed based on a detection signal from the paper transport unit paper detection unit. The paper interval is calculated by calculating the time when the trailing edge of the paper reaches the delivery position of the paper feed device, turning on the paper feed clutch at the calculated timing, and feeding in the continuous feed state. In light of the fact that complicated control is unavoidable due to the presence of paper, the burden associated with transport control is reduced without providing paper intervals, paper intervals are provided only where necessary, and machine life and maintenance intervals are shortened. Productivity can be increased without increasing noise and cost. Also, an image forming apparatus that can reduce a burden related to conveyance control since no sheet interval is provided has been proposed.
JP 2003-176045 A JP 2004-1930 A

  However, in the sheet conveyance of the image forming apparatus having a plurality of sheet feeding trays as in Patent Documents 1 and 2, the sheet is fed from another sheet feeding tray immediately after the sheet is fed from the sheet feeding tray. In this case, a positional distance is generated, and the paper conveyance speed is reduced. This still has room for improvement.

  Therefore, in the present invention, during continuous feeding from different paper feeding trays, the position of the paper being fed is calculated based on the detection signal from the paper detection unit, and the conveyance of the paper being fed is temporarily stopped. It is an object of the present invention to provide an image forming apparatus that continues to convey subsequent sheets up to a predetermined sheet interval.

  In order to achieve the above object, the invention according to claim 1 is characterized in that a sheet feeding unit that feeds sheets stacked on a sheet feeding tray and a conveyance unit that conveys the sheet fed from the sheet feeding unit. Means, an individual driving means for individually driving the transport means, a transport section paper detecting means for detecting the paper fed by the paper feed means, and the transport during continuous feeding from different paper feed trays Position calculating means for calculating the positions of the leading and trailing edges of the paper being fed based on a detection signal from the paper detection means, and a plurality of papers fed from the different paper feed trays are individually paused The image forming apparatus includes: a pause control unit that controls; and a conveyance continuation unit that continues conveyance of the following sheet to a predetermined sheet interval when conveyance of the sheet being fed is temporarily stopped. It is characterized by.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control unit performs the control by reducing the sheet interval.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the temporary stop by the temporary stop control unit is controlled by driving a plurality of motors by the individual driving unit. It is characterized by.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the first or second aspect, the temporary stop by the temporary stop control unit is controlled by arranging a clutch on the transport path by the individual driving unit. It is characterized by performing.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the position calculating unit detects a leading edge of the paper and determines a trailing edge position of the paper being fed from the detection timing. It is characterized by calculating.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the first aspect, the position calculating unit detects the rear end of the paper and detects the rear end position of the paper being fed from the detection timing. Is calculated.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control means sets the timing of the temporary stop when waiting for an image at the registration position.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control means sets the timing of the temporary stop to the color mode switching waiting time.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control means sets the timing of the temporary stop to a fixing temperature setting waiting time.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control means sets the timing of the temporary stop at the time of image quality adjustment.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to the first aspect, the temporary stop control unit performs a set for individually performing the temporary stop control at a break of a conveyance load.

  According to the present invention, during continuous sheet feeding from different sheet feeding trays, sheet feeding is controlled, the position of the sheet being fed is calculated based on the detection signal from the conveyance sheet detecting unit, It is possible to provide an image forming apparatus that conveys a sheet without reducing the sheet conveyance speed by continuing to convey subsequent sheets until a predetermined sheet interval when conveyance of the sheet is temporarily stopped.

  The present embodiment aims to prevent continuous printing performance from being deteriorated by individually controlling the sheet conveyance even when the sheet interval is widened during sheet conveyance.

  FIG. 1 is a schematic view of the exterior of the image forming apparatus of the present embodiment.

  As shown in FIG. 1, the image forming apparatus according to the present exemplary embodiment includes a paper feed tray 10 including a first tray, a second tray, a third tray, a fourth tray, and a fifth tray.

  The width of the sheet interval at the time of sheet feeding in the image forming apparatus of this embodiment will be described with reference to FIG. FIG. 2A is a schematic diagram illustrating a sheet interval when the image forming apparatus according to the present exemplary embodiment feeds paper from the fifth tray immediately after feeding the first tray.

  When the sheet (2) is fed from the fifth tray immediately after the sheet (1) is fed from the first tray, the sheet interval between the sheet (1) and the sheet (2) depends on the position of the sheet feed tray. The distance will be generated by the difference.

  A sheet conveying unit of the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 2B is a schematic diagram of the paper transport unit of the image forming apparatus according to the present embodiment.

  The sheet conveyance in the image forming apparatus of the present embodiment is performed using the conveyance roller 6 and the conveyance sensor 5 for each of the first to fifth trays. The continuation means for continuing the conveyance of the succeeding paper (2) fed from the fifth tray is performed by individually driving the rollers, and this roller driving method is a CPU that controls all the conveyance control of this embodiment. Thus, the individual clutch is controlled and driven by the individual clutch. In the leading edge detection method, the leading edge of the preceding sheet (1) fed from the first tray is detected by the transport sensor 5 and the trailing edge position of the sheet being fed is calculated from this detection timing. Then, the determination unit determines whether the sheet interval from the preceding sheet is wide. In the trailing edge detection method, the trailing edge of the preceding sheet (1) fed from the first tray is detected by the transport sensor 5 and the trailing edge of the sheet being fed is detected from this detection timing. The position is calculated, and the determination unit determines whether the sheet interval from the preceding sheet is wide. The preceding sheet (1) fed from the first tray is temporarily stopped, and the conveyance of the succeeding sheet (2) fed from the fifth tray is continued to a predetermined sheet interval position. This temporary stop factor can be any of waiting for an image at the registration position, fixing temperature setting waiting time, color mode switching waiting time, or image quality adjustment time. To what extent the conveyance of the succeeding paper (2) fed from the fifth tray is continued is to convey it to a conveyance roller that uses the same motor in the paper conveyance unit of the image forming apparatus of this embodiment. Can be realized.

  The conveyance control of the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram of conveyance control of the image forming apparatus according to this embodiment.

  As shown in FIG. 3, the CPU 7 includes the first sensor 1, the second sensor 2, the third sensor 3, the fourth sensor 4, the first motor 11, the second motor 12, the first clutch 21, and the second clutch 22. Control everything. The first sensor 1 to the fourth sensor 2 detect paper. The first motor 11 and the second motor 12 convey paper. The first clutch 21 and the second clutch 22 transmit driving. The image forming apparatus of the present embodiment has a plurality of sensors for detecting paper, and has a plurality of motors and clutches for individually controlling conveyance.

  A driving structure for paper feeding and conveyance according to the present embodiment will be described with reference to FIG. FIG. 4 is a drive configuration diagram of paper feeding and conveyance in the paper conveyance unit of the present embodiment.

  A sheet feeding unit and a driving configuration of the conveying unit in the sheet conveying apparatus of the present embodiment will be described. As a whole, the driving force of the driving motor 9 is distributed to the conveying roller 19 and the paper feeding roller 16 via the timing belt 27. A gear 23 is attached to the output shaft of the drive motor 22, and a transport clutch 25 is connected to a gear 24 that meshes with the gear 23. A gear 26 is attached to the shaft of the gear 24, and the timing belt 27 is driven by the gear 26. A gear 28 that meshes with the timing belt 27 is provided, a gear 29 meshes with the gear 28, and a gear 31 is attached to the gear 29. The gear 29 is provided with a paper feed clutch 30. A gear 35 and a paper feed roller 16 are attached to the shaft of the gear 29. A gear 36 is attached to the gear 35, and a gear 37 attached to the shaft of the feed roller 15 is attached to the gear 36. With the configuration shown in FIG. 4, the feed roller 15 and the paper feed roller 16 rotate synchronously.

  A gear 32 is attached to the shaft of the gear 31, and a gear 33 attached to the shaft of the separation roller 17 is attached to the gear 32. A torque limiter 14 is provided on the shaft of the separation roller 17. Therefore, the paper feeding method of the paper feeding means 11 in this embodiment is an FRR paper feeding method based on a combination of the feed roller 15, the paper feeding roller 16, the separation roller 17, and the torque limiter 14 whose rotation direction can be switched. The separation method is not particularly limited as long as it is a friction separation method using a sheet feeding roller 16 and a separation member of a roller or a separation pad. Although the drive configuration corresponding to the lower stage of the paper feed tray 10 has been described, this configuration is the same in the upper stage. Although not shown, the conveying roller 19 is also driven by the driving force of the driving motor 9, and the feeding roller 15, the feeding roller 16, and the conveying roller 19 are collectively moved by the operation of the conveying clutch 25 arranged immediately after the driving motor 9. Turned on / off.

  After distributing the driving force from the driving motor 9 to the feeding roller 15, the feeding roller 16, the separating roller 17, and the conveying roller 19, a clutch is arranged so that the driving of each roller is controlled by a plurality of clutches or stepping is performed on each roller. A drive source such as a motor may be directly connected, and rotation may be controlled by an on / off operation of the drive source. The registration roller (not shown) is adapted to receive a driving force from a driving source (not shown) via a registration clutch (not shown). You may make it drive by a direct drive source not via a registration clutch.

  A series of paper conveyance processes of the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 5 is a block diagram showing a series of paper conveyance processes of the image forming apparatus according to this embodiment.

  When paper feeding is started from different paper feeding trays at the same time, the positional paper spacing of the paper feeding trays occurs. If the conveyance is continued, the preceding sheet fed from the first tray is temporarily waiting for the image, so that the conveyance of the subsequent sheet is temporarily stopped (step S1). At this time, it is determined whether or not the succeeding sheet fed from the fifth tray has a wide sheet interval from the preceding sheet (step S2). As a result of the determination, if it is determined that the subsequent sheet fed from the fifth tray is to be conveyed (step S2 / YES), the conveyance is continued (step S3). By continuing the conveyance, it is possible to reduce the sheet interval from the preceding sheet fed from the first tray, and it is possible to prevent the continuous printing performance from being deteriorated. At this time, the means for continuing the conveyance of the succeeding paper (2) fed from the fifth tray can be realized by driving the roller individually by an individual motor according to the block diagram of FIG.

  Productivity can be improved even when the conveyance start position is different by the control for conveying the object continuously.

1 is an overview of an image forming apparatus according to an embodiment. (A) is a figure which shows typically description of the sheet | seat space | interval in this embodiment. FIG. 4B is an overview diagram illustrating sheet conveyance of the image forming apparatus according to the present exemplary embodiment. 3 is a block diagram illustrating conveyance control of the image forming apparatus according to the present exemplary embodiment. FIG. FIG. 3 is a drive configuration diagram illustrating sheet feeding and conveyance of the image forming apparatus in the present embodiment. FIG. 5 is a flowchart illustrating individual control of sheet conveyance in the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st sensor 2 2nd sensor 3 3rd sensor 4 4th sensor 5 Conveyance sensor 6 Conveyance roller 7 CPU
9 drive motor 10 paper feed tray 11 first motor 12 second motor 21 first clutch 22 second clutch

Claims (11)

A paper feeding means for feeding the paper loaded in the paper feed tray;
Transport means for transporting the paper fed from the paper feed means;
Individual driving means for individually driving the conveying means;
A conveyance section paper detection means for detecting the paper fed by the paper feed means;
Position calculating means for calculating the positions of the leading edge and the trailing edge of the paper being fed based on a detection signal from the conveying section paper detecting means during continuous paper feeding from different paper feed trays;
A pause control means for individually pause-controlling a plurality of sheets fed from the different sheet feed trays;
An image forming apparatus comprising: a conveyance continuation unit configured to continue conveyance of a succeeding sheet up to a predetermined sheet interval when conveyance of the sheet being fed is temporarily stopped.   The image forming apparatus according to claim 1, wherein the pause control unit performs control by reducing the sheet interval.   The image forming apparatus according to claim 1, wherein the temporary stop by the temporary stop control unit is controlled by driving a plurality of motors by the individual driving unit.   The image forming apparatus according to claim 1, wherein the temporary stop by the temporary stop control unit is controlled by arranging a clutch on a transport path by the individual driving unit.   The image forming apparatus according to claim 1, wherein the position calculating unit detects a leading edge of the sheet and calculates a trailing end position of the sheet being fed from the detected timing.   The image forming apparatus according to claim 1, wherein the position calculating unit detects a rear end of the paper and calculates a rear end position of the paper being fed from the detected timing.   The image forming apparatus according to claim 1, wherein the temporary stop control unit sets a timing of the temporary stop when waiting for an image at a registration position.   The image forming apparatus according to claim 1, wherein the suspension control unit sets the timing of suspension to a color mode switching waiting time.   The image forming apparatus according to claim 1, wherein the temporary stop control unit sets the timing of the temporary stop to a fixing temperature setting waiting time.   The image forming apparatus according to claim 1, wherein the temporary stop control unit sets the timing of the temporary stop at the time of image quality adjustment.   The image forming apparatus according to claim 1, wherein the pause control unit performs a set for which pause control is individually performed at a break of a conveyance load.

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