JPH0211902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control system for an electrophotographic copying machine that allows desired copying to be performed without reducing the copying speed.

Recently, an electrophotographic copying machine having an automatic document feeding mechanism has been proposed, and FIG. 1 shows a schematic configuration of one example thereof. Inside the main body of the copying machine 1, as in a normal copying machine, an original M conveyed and placed on a document table 11 by an automatic document feeding mechanism 3, which will be described later, is exposed to light, and reflected light from the original M is transferred to a photosensitive drum. 13; a photosensitive drum 13 on which an electrostatic latent image of the document is formed on a photosensitive member provided on the surface; and a charging system that uniformly charges the photosensitive member around the photosensitive drum 13. a developing device 15 that develops the electrostatic latent image formed on the photoreceptor into a visible image, and a transfer electrode 16 that transfers the visible image on the photoreceptor onto recording paper P.
, a separation electrode 17 that separates the recording paper P from the photosensitive drum surface after transfer, a conveyor belt 18 that transports the separated recording paper to the fixing device 19, and a cleaning device 20 that removes the developer remaining on the photosensitive drum. is located. A large number of recording papers P are stored in a paper feed cassette 21, and are conveyed one by one by paper feed rollers 22, once stopped, and fed to a transfer position by registration rollers 23 in synchronization with the copying operation. Reference numeral 24 denotes a paper discharge tray from which the copied recording paper is discharged.

On the other hand, an automatic document feed mechanism 3 is arranged on the main body of the copying machine 1. The automatic document feed mechanism 3 includes a document placement table 31 on which a plurality of documents M are placed, a document feed belt 32 driven by a document feed motor (not shown), and a document feed belt 32 that moves the documents M on the main body of the copying machine 1. It has a document stopper 33 that stops at a proper position on the table 11.

Inside the main body of the copying machine 1, there is a paper feed end sensor located just before the registration roller 23 along the conveyance path of the recording paper P.
S ₁ is provided, and when the leading edge of the recording paper P fed by the paper feed roller 22 reaches the paper feed end sensor S ₁ consisting of, for example, a micro switch, the paper feed roller 22 is stopped and the recording paper P is temporarily stopped. do. Further, the automatic document feeding mechanism 3 is provided with a document leading edge detection sensor S ₂ near the leading edge of the document table 11 on the main body of the copying machine 1 .

In the electrophotographic copying machine having the above-mentioned automatic document feeding mechanism, the feeding timing of the recording paper P is as follows.
There are two times: (1) when the automatic document feed mechanism starts feeding the document, and (2) when the document is set at the correct position on the document table 11. According to the timing (1) above, since the original is sent out and the recording paper is fed at the same time, wasted time can be reduced and the copying speed can be improved. If a document jam occurs in the copying machine 1, the recording paper has already been fed and is still inside the main body, so if you start copying after clearing the document jam, the recording paper will be fed again and double feeding will occur. The paper will be done. Conventionally, therefore, a paper jam is displayed for recording paper that has already been fed inside the main body of the copying machine, and the paper is handled as a paper jam. Another method is to use the already fed recording paper in the main unit without causing a paper jam when the copying operation is restarted. Conceivable. In addition to the problem of complicated controls and mechanisms, this method requires the user to stop copying when such a document jam occurs, and another user may have to repeat the process from the previous time (i.e. inside the copying machine). If you use recording paper of a different size from the recording paper that has already been fed, copies will be made on recording paper of an undesired size.

On the other hand, according to the timing in (2) above, there is no problem that would occur if the timing in 1 is used above, but the recording paper is not fed at all while the original is being fed. Another problem is that the copy speed is reduced.

The present invention has been made in view of the above points,
This problem is solved by feeding the recording paper and sending out the document at the same timing and by storing the size of the fed recording paper. Specifically, a control means, a means for detecting the recording paper size, a storage means for storing the detected recording paper size, a means for setting the recording paper size,
a document detecting means for detecting a document jam in the automatic document feeding mechanism; the control means determines that the document is jammed based on the output of the document detecting means, and thereby controls the copying process to an intermediate stage; after the intermediate stage; When the copy start operating means is operated after the recording paper size setting means sets the size of the recording paper to be copied for a new document to be copied, the control means adjusts the size from the setting means. The signal is compared with the recording paper size signal which is waiting in the apparatus main body and stored in the storage means, using a comparison means, and based on the output from the comparison means that the sizes are the same, it is determined that the paper size has already been fed. A copying operation is started for the recording paper that is currently being fed, and the already fed recording paper is discharged based on the output from the comparing means that the sizes are different.

The present invention will be explained below with reference to the timing chart shown in FIG. 2 of the drawings.

In Figure 2, (a) is (1) a normal case in which no original jam occurs in the automatic document feed mechanism, and (b) is (2) a case in which a document jam occurs in the automatic document feed mechanism and copying is continued using the same size of recording paper. Similar to (b), (c) shows a timing chart for the case (3) where a document jam occurs but copying continues afterward using recording paper of a different size. A document jam in the automatic document feed mechanism is detected by determining that the document is jammed if the leading edge of the document does not reach the document leading edge detection sensor _S2 within a predetermined time after the document feed motor starts operating.

First, case (1) will be explained.

When a copy start operating means (not shown) is operated at time T ₀ , a paper feed clutch (not shown) is operated inside the copying machine main body, and the recording paper P is fed by the paper feed roller 22, and the automatic document Feeding mechanism 3
Then, the document feed motor (not shown) is energized, the document feed belt 32 is driven, and the document M is moved onto the document table 11.
will be transported towards. At the same time, the optical scanning system 1
The exposure lamp No. 2 is turned on, and the main motor for rotating the photosensitive drum 13 is energized and starts rotating. After that, the leading edge of the recording paper becomes the paper feed end sensor.
When the position S ₁ is reached (time T ₁ ), the sensor S ₁ outputs an output, but the paper feed clutch becomes inactive, and the recording paper P engages with the registration roller 23 and stops at that position. On the other hand, the document M continues to be fed and when it reaches the proper position on the document table 11 (time T ₂ ), the leading edge of the document M is detected by the document leading edge detection sensor S ₂ , so that the document feeding motor and the document feeding belt 32 , the document M stops at its normal position. At this time, the forward clutch (not shown) of the optical scanning system 12
energized, the optical scanning system 12 starts forward movement and exposes the original M. Shortly thereafter, at time _T3 , the registration rollers 23 are driven to rotate, and the recording paper P, which had been stopped until then, is conveyed toward the transfer position.
At time _T4 , the registration roller 23 stops, the forward clutch of the optical scanning system 12 is deenergized, and a backward clutch (not shown) is energized instead, so that the optical scanning system 12 begins to move backward. At this time, the exposure lamp is turned off. Since the trailing edge of the recording paper P passes the paper feed end sensor _S1 a little before this time _T4 , its output becomes "0". The forward clutch is the time
Since it is deenergized at _T5 , the optical scanning system 12 stops at the start position. Through the above series of operations, an electrostatic latent image of the document is formed on the photoreceptor of the photoreceptor drum 13.
Thereafter, a series of electrophotographic processes such as development, transfer, and fixing are performed, and one copying cycle ends when the recording paper P is discharged onto the paper discharge tray 9 at time _T6 .

Next, case (2) will be explained.

In this case, a document jam occurred in the previous copying cycle, the copying process was interrupted, and although the document jam was cleared, the recording paper fed in the previous copying cycle was already in the copying machine, so the recording paper size The recording paper size of the previous copying cycle is stored in the storage means. Therefore, even if the copy start operating means (not shown) is operated at time _T0 , the comparison means outputs a signal indicating that the sizes are the same, so the paper feed roller 22 is not operated and paper is not fed. At this time, other operations such as document feeding operation, lighting of the exposure lamp, and start of driving of the main motor at _T0 , and subsequent operations are exactly the same as in case (1), so explanations thereof will be omitted. In this case also the time
The copy cycle ends at T ₆ .

Next, case (3) will be explained.

In this case, as in case (2), a document jam occurred in the previous copying cycle and the document jam was cleared, but recording paper fed in the previous copying cycle was already inside the copying machine main body. However, unlike case (2),
The size of the recording paper to be copied, which is newly set by the recording paper size setting means, is different from the size of the recording paper installed in the copying machine main body (stored in the storage means). Therefore, when the copy start operation means is operated at time _T0 , the main motor is driven based on the output from the comparison means that the sizes are different, and the registration roller 23 is driven.
operates to eject the recording paper inside the copying machine. At this time, the paper feed end sensor _S1 continues to output since the recording paper P is passing through. then time
At T ₀ ', the trailing edge of the recording paper passes the paper feeding end sensor S ₁ , so the output of the sensor S ₁ becomes "0" and at the same time, the registration roller 23 becomes inactive. In this way, the recording paper already in the copying machine main body is ejected. Therefore, further at this time T ₀ ′,
The paper feed roller 22 is actuated to feed different sizes of recording paper, and in the automatic document feed mechanism, the document feed belt 32 can also be driven to feed the document M and start a copying cycle. The operations of the copying machine main body and the automatic document feed mechanism after this time T ₀ ' are exactly the same as in case (1), so the explanation thereof will be omitted.

In actual copying operations, the control means determines that a document is jammed in the automatic document feeding mechanism based on the fact that there is no output from the document leading edge detection sensor _S2 (document detection means) within the time period _T0 to _T2 . To determine whether the size of the recording paper in the copying machine is the same as the size of the recording paper to be copied next, detect the shape of the cassette containing the recording paper or the size of the recording paper using the size selection button. Comparing the output of the recording paper size signal stored in the storage means with the signal of the newly fed recording paper size set by the recording paper size setting means such as a size selection button. Use them to compare and judge. the result,
After the control means determines that a document jam has occurred, the copying process is interrupted, and after this interruption, the same size as the previous recording paper is set by the recording size setting means, and then the copying start operation means is operated. When this happens, the control means uses a comparing means to compare the size signal from the setting means with the recording size signal stored in the storage means that is waiting in the main body of the apparatus, and determines that the sizes of the recording sheets are the same. When the comparing means outputs the output, the process for the case (2) above is used, and when the comparing means outputs the output that the recording paper sizes are different, the process for the case (3) above is used. do.

As explained above, in the present invention, when a document jam is detected in an electrophotographic copying machine equipped with an automatic document feeding mechanism and in which a document and recording paper are fed simultaneously, the following operation of the copying operation means is performed. The size of the fed recording paper and the size of the recording paper to be copied are compared, and if they are the same, the copying process is performed sequentially without feeding the recording paper, and if they are different, the fed recording paper is ejected. This improves the copying speed while ensuring that copies are not made on recording paper that the user does not want, and the recording is performed only when the recording paper that the user desires is located at the position of the registration roller in the main body of the device. Since copies are made on paper, desired copies can be made.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electrophotographic copying machine having an automatic document feeding mechanism, and FIG. 2 is a timing chart of a control system according to the present invention. DESCRIPTION OF SYMBOLS 1... Copying machine, 11... Document table, 12... Optical scanning system, 13... Photosensitive drum, 14... Charger, 15... Developing device, 16... Transfer electrode, 17... Separation electrode, 18
...Conveyor belt, 19...Fixing device, 20...Cleaning device, 21...Paper feed cassette, 22...Paper feed roller, 23...Register roller, 24...Sheet discharge plate, 3...
Automatic document feed mechanism, 31... document placement table, 32... document feed belt, 33... document stopper.

Claims (1)

[Claims] 1. A method for controlling a copying apparatus which is equipped with an automatic document feeding mechanism and in which a document and recording paper are fed simultaneously by operating a copy start operation means, comprising: a control means, a means for detecting recording paper size; The control means includes a storage means for storing the detected recording paper size, a means for setting the recording paper size, and a document detection means for detecting a document jam in the automatic document feeding mechanism, and the control means is configured to control the document detection means. The copying process is interrupted by determining that the document is jammed based on the output of When the copy start operation means is operated, the control means compares the size signal from the setting means with a recording paper size signal waiting in the main body of the apparatus and stored in the storage means using a comparison means. Based on the output from the comparing means that the sizes are the same, the copying operation is started for the already fed recording paper, and based on the output from the comparing means that the sizes are different, the copying operation is started for the already fed recording paper. 1. A method for controlling a copying apparatus, comprising ejecting recording paper that has been loaded.