JPS60233662A - Control device for copying machine - Google Patents

Abstract

PURPOSE:To stop driving of a copying machine and to suppress generation of a cleaning defect by detecting overlapped feed of paper from a double-side tray and stopping driving of the copying machine prior to starting of an exposing operation. CONSTITUTION:Conveyance change-over selectors 16, 18 are changed over to positions 16b, 18b of dotted lines and paper is guided by the selector 16 and is delivered onto a discharge paper tray 15 on the outside of the machine in the stage of performing a copying operation in an ordinary copying mode. The copying operation on the front of the copying paper is first carried out in the case of performing the copying operation in a double-side mode. More specifically, the selectors 16, 18 are changed over to the positions 16a, 18a of solid lines and the copying paper fed from a paper feed cassette 9 is delivered to a double-side tray 13 via selectors 16a, 18a after the required copying operation. When plural sheets of the copying paper are simultaneously fed by feed rollers 23 for the purpose of copying the rear side, the feed is detected by an overlap feed detector 23 which emits an overlap feed detection signal to operate a control part 27. Said part outputs a control command to a driving part 28 to stop a scanning mechanism 3, a photosensitive drum 6, etc. The drum 6 is thus not exposed and therefore the generation of the cleaning defect is obviated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device for a copying machine equipped with a double-sided copying function, and in particular, when double-feeding of copy paper on which front side copying has been completed occurs, the control device for the exposure operation is controlled. The present invention relates to a control device for a copying machine that stops a copying operation before it starts.

[Conventional technology]

In a conventional copying machine, for example, copy paper is taken out from the paper feed tray, transferred to the front side, then temporarily transported to the duplex tray, then the copy paper is fed from the duplex tray, and copies are made on the back side. There is a double-sided copy machine.

According to this copying machine, when an original is set on the platen and a copy operation is commanded, the paper whose front side has been copied is stored in the duplex tray, and then when the original is set on the back side and a copy operation is commanded, the paper is stored in the duplex tray. , paper is fed from the duplex tray, the back side is copied, and the paper is ejected to the ejection tray.

Even if the document has multiple pages, the front side is continuously copied, and the number of sheets equal to the number of pages is stored in the duplex tray, waiting for the back side copying operation.

[Problem that the invention seeks to solve]

However, with conventional copying machines, if the paper stored in the double-sided tray is fed in duplicate, the pages will be misaligned, resulting in wasted paper. Even if the photoreceptor is stopped, there is a risk that cleaning failure will occur because the photoreceptor is still being developed.

[Means and effects for solving the problems] The present invention has been made in view of the above, and in order to prevent page misalignment of back side copies and suppress the occurrence of cleaning defects,
The present invention provides a control device for a copying machine that stops driving the copying machine prior to starting a color exposure operation when double feeding of sheets from a double-sided tray is detected.

〔,Example〕

Hereinafter, a copying machine control device according to the present invention will be explained in detail.

Figure wJ1 shows an embodiment of the present invention, in which a platen 2 on which a document 1 is placed, a scanning mechanism 3 that optically scans the document 1 placed on the platen 2, and a scanning mechanism 3 attached to the platen 2. a motor 4 that reciprocates horizontally along the scanning mechanism 3; a group of mirrors 5 that reflects in a predetermined direction the light emitted from the exposure lamp of the scanning mechanism 3 and reflected on the document surface; A photoreceptor drum 6 whose surface is exposed to light to form a latent image, a developer unit 8 which applies toner to the latent image formed on the surface of the photoreceptor drum 6 and develops it, and a copying paper 10. A transfer device 11 transfers the visible image formed by the accommodated paper feed cassette 9 and the developing device 8 onto the copy paper 10 fed from the paper feed cassette 9, and the visible image is transferred. A paper feed belt 12 that feeds the copy paper 10 into the paper feed cassette 9 at the same time as the copy paper 10 arrives at the container 11, and a double-sided tray that temporarily stores the copy paper that has been copied on one side in preparation for double-sided copying. 13 and double-sided tray 13 or paper cassette 1
a conveyance mechanism 14 that conveys the copy sheets of 9 and 9 to a transfer position;
A discharge tray 15 that stores copied paper after copying, a selector 16 that selects the conveyance destination of the copy paper after being transferred to the duplex tray 13 or the discharge tray 15, a solenoid 17 that drives the selector 16, and the duplex tray 13. ] A selector 18 that is rotated when feeding copy paper to the transport mechanism 14, a solenoid 19 that drives the selector 18, and a tray sensor that detects the presence of copy paper 21 on the double-sided tray 13. 20, an ejection sensor 22 that detects when copy paper is ejected to the ejection tray 15, a paper feed roll 23 that feeds the copy paper 21 from the duplex tray 13, and a paper feed roll 23 that feeds the copy paper 21 only when discharging the copy paper 21. Transfer roll 23 to copy paper 2
Roll drive 11 [24 sheets, double-sided tray 1]
3. A detection device 25 that detects double feeding of copy paper 21 that is dispensed from the third page, and buttons provided on the top of the copying machine body for setting the number of copies, magnification, mode, copy paper size, etc., and displaying various setting contents. a control unit 27 that executes single-sided and double-sided copying processing, etc. based on information from the console 26, various sensors, the tray sensor 2°, and the ejection sensor 22; The drive unit 28 is configured to drive the motor, solenoid, corotron, etc. of each drive mechanism according to the control command given.

In the above configuration, the number of copies, copy mode, reduction ratio, paper size, etc. are set using the console 26, and the original l is placed on the platen 2. When the copy start button on the console 26 is pressed, the exposure lamp of the scanning mechanism 3 is turned on and the motors 4 and 7 are driven.The scanning mechanism 3 starts running and the photosensitive drum 6 starts rotating. Note that in the double-sided copying mode, the selector 16 is located on the upper side, and the selector 18 is located on the lower side.As the scanning mechanism 3 scans, the surface of the photoreceptor drum 6 is sequentially exposed to light. The formed latent image is developed with toner by the developing device 8. At the same time that the visible image produced by the toner development reaches the transfer device 11, one sheet of copy paper is transferred from the paper feed cassette 9 to the paper feed belt 12. The fed copy paper is sent to the transfer position by the transport mechanism 14.The next copy paper sent to the transfer position is transferred with the visible image on the photoreceptor drum surface by the transfer device 11, and the transferred copy paper is transferred to the transfer position. After the copy paper is fixed by a fixing device (not shown), it is ejected to the output tray 15 in the single-sided copy mode, and sent to the duplex tray 13 in the duplex copy mode. The paper feed roller 23 that feeds the paper 21 is raised upward so as not to obstruct the paper from entering the duplex tray 13.
When the paper has been placed above, the paper feed row 223, which had been retracted upward, comes down to the paper, and the preparation for paper feeding is completed again. In the double-sided copy mode, when the first original is copied, the paper is fed to the double-sided tray 13 by the selector 16, and the second original is placed on the platen 2 and scanned. Accordingly, the roller drive mechanism 24 is driven at an appropriate time, and the selector 18 is
is rotated clockwise by the solenoid 19, and the selector 16 is further rotated clockwise by the solenoid 17. This allows the double-sided tray 13 to be removed from the paper feed row 2.
Copy paper 21 is fed by a conveyor 23.

It is delivered to the transfer mechanism 14 and transported to the transfer position by the nuclear mechanism. Note that when the paper feed row 223 is being driven, the paper feed belt 12 is not driven. This paper feed belt 12
Stop control is performed based on the detection signal of the tracer/sustainer 20. The paper with the contents of the second manuscript copied on the back side is
After being fixed, the paper is ejected to the ejection tray 15.

Thereafter, the above-described process is repeated every time a copying process is executed, and a double-sided copy is made.

Figure 2 (A), (→ indicates a detection device 25, in which piezoelectric elements 25a are provided at intervals on the outer periphery of one of the pair of rolls, and a voltage corresponding to the number of sheets fed is output to the control unit. (The voltage according to the thickness of a sheet of paper is stored in advance for each type of paper.)
.

The pressure applied to the piezoelectric element 25a when one sheet of copy paper is passed is different from the pressure applied to the piezoelectric element 25m when a plurality of copies are passed simultaneously, and the output voltages are also different accordingly. Utilizing this fact, by setting a reference voltage in advance when one sheet of copy paper passes through, and detecting that the output voltage exceeds this reference voltage when multiple sheets of copy paper pass at the same time. Detects double feeding of copy paper.

Now, when the copying machine shown in FIG. 1 is configured to perform a copying operation in the normal copying mode, the conveyance path switching selector 16.18 is at the position 16b indicated by the dotted line in FIG.

18bK is switched, and the copy paper fed by the paper feed force set 9 is copied by the necessary copying operation, and then guided to the conveyance path switching selector 16b and placed on the paper discharge tray 15 outside the machine. When the paper is ejected and the copy mode is double-sided copy mode and a copy operation is to be performed, the process shown in FIG. 3 is executed. When performing a copying operation on the surface of copy paper, the conveyance path switching row 2
16.18 is switched to the solid line positions 16m and 18a in FIG. Selector 168. The paper is discharged onto the double-sided tray 13 via the paper 18a. By the way, when performing a copying operation on the back side of copy paper, the double feed detection device 25 detects that multiple sheets of copy paper are simultaneously fed from the double-sided tray 23; In response to the double feed detection signal, the control section 27 is activated, and the control section 27 sends a control command to the drive section 2 in a predetermined format and timing.
7, and immediately sends the output to the scanning mechanism 3, via the drive unit 28.
Photosensitive drum 6, transfer device 11. The paper feed bell) 1249 is stopped.

At this time, the scanning mechanism 3 has not started scanning, and therefore the photosensitive drum 6 is not exposed. Furthermore, it is desirable to set the impersonation timing so that the photoreceptor drum 6 is not charged for bonding.

〔Effect of the invention〕

As explained above, according to the copying machine control device of the present invention, the drive of the copying machine is stopped prior to starting the exposure operation when double feeding of paper is detected from the double-sided tray, so that the copying machine can be copied on the back side. It can eliminate page errors and cleaning defects.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a double feed detection device, and Fig. 3 is a flow diagram explaining the process of the present invention. , 13... double-sided tray, 15.
・・Output tray, 16. 18・・Selector, 25・
...Double feed detection device.

Claims (1)

[Scope of Claims] A copying machine that stores a sheet on which the front side has been copied in a duplex tray, performs a back side copy on the sheet fed from the duplex tray, and discharges the sheet to an output tray, comprising: The apparatus is characterized in that it is provided with means for detecting double feeding of the paper, located on the paper feed side, and a control section that stops driving the copying machine before starting the color exposure operation when the double feeding is detected. Control device for copying machines.