JPH0437419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an electronic copying machine equipped with an automatic document feeder.

``Prior Art'' Generally, in an electronic copying machine, an original is placed on a platen glass and an operator presses a print start button to copy the original onto copy paper. However, it is not only time consuming for the operator to repeat this task for a large number of manuscripts, but also is not desirable in terms of office efficiency.

Therefore, an automatic document system that automatically transports originals one by one onto this platen glass, automatically starts printing, and after copying is completed, ejects the original and supplies the next new original. A transport device has been developed.

FIG. 5 shows a longitudinal sectional view of the automatic document feeder 1.

This device is supported by three legs (not shown) and placed at a predetermined position above the platen glass 2. On the top of this device, there is a document 4 to be copied.
A document tray 3 for accommodating documents is provided. A feed belt 5 is provided at the lower right of the document tray 3 to feed the documents 4 sequentially from the bottom layer. This feed belt 5 is equipped with an air suction mechanism 5', which sucks the leading edge of the lowest document 4 and sends it out in the direction of arrow 6.

A guide plate 7, a feed roller 8 and two pinch rollers 9 are provided in front of the guide plate 7. Further, the claw 11 is in an open state as shown by the broken line.

After being pulled out by the feed belt 5, the document 4 advances along a guide plate 7, and is conveyed onto the platen glass 2 below by a feed roller 8 and a pinch roller 9.

A conveyor belt 12 is provided directly above the platen glass 2 to convey the original to a final copying position. This conveyor belt 12 conveys the original in the direction of arrow 16.

A registration gate 13 is provided at the left end of the platen glass 2 to stop the progress of the transported original 4 and stop the original 4 at a predetermined copying position.
Also, in the vicinity of this registration gate 13, the original 4
A registration sensor 14 is installed in the copying position for detecting when the leading edge of the original 4 reaches the registration gate 13 and outputting a detection signal for operations such as starting exposure.

After exposure, the registration gate 13 is opened and the conveyor belt 12 conveys the document in the direction of arrow 16, and the document is discharged to the outside via the guide plate 17 and the discharge roller 18.

Further, when the original has images to be copied on both sides, after the exposure is completed, the conveyor belt 12 is reversed and conveys the original 4 in the direction of the arrow 21. The original 4 is fed backward along the guide plate 7, and at this time, the feed roller 8 is also reversed in the same direction. The claw 11 now enters the conveyance path as shown by the solid line in the figure, advances the document 4 along the guide plate 22, and then moves the document 4 along the conveyance belt 12 again.
Send it under.

At this time, the document 4 has just been turned over, and the side opposite to the previous side will be exposed.

In order to synchronize the feeding of the original 4 of such an automatic document feeder, the opening and closing of the register gate 13, and the timing of exposure, this device and the main body of the electronic copying machine are connected by a signal cable (not shown).

FIG. 6 shows a longitudinal sectional view of a conventional electronic copying machine equipped with this automatic document feeder.

The automatic document feeder 1 is placed above the platen glass 2, and the optical system 26 is placed below.

The image drawn on the original document 4 is configured to be formed on the upper surface of a belt-shaped photoreceptor 27 by this optical type 26. Exposure is instantaneously performed by a flash light source (not shown).

The photoreceptor 27 rotates in the direction of an arrow 28, is developed by a developing device 29, passes through a transfer device 31, and is transferred to a charger 3.
2 and then returns to the exposure section again.

Copy paper 33 is stored in two paper feed devices 34, and is pulled out one by one, passes through the path indicated by the broken line arrow 36 in the figure, is transferred by the transfer device 31, and is transferred by the fixing roller 37. It will be established. After that, the output roller 38 outputs the paper onto the output tray 40, but in the case of double-sided copying, the auxiliary tray 3
Sent to 9 and turned over. And again arrow 3
Copying of the back side is performed through route 6.

Normally, in such an electronic copying machine, when an operator first sets a predetermined number of originals 4 on the original tray of the automatic document feeder 1 and presses a print start button on a console panel (not shown), the originals start printing as shown in FIG. The paper is fed to a copying position above the platen glass 2 by the feed belt 5, the feed roller 8, and the conveyor belt 12.

The registration gate 13 is closed at this time, and the registration sensor 14 detects that the document has been sent there and outputs a detection signal. Next, in FIG. 6, the copy paper 33 is fed out from the paper feeder 34, and the flash light source is turned on at a predetermined timing to perform exposure. After that, the photoreceptor 27 is developed,
This is transferred onto the copy paper 33, and the copy paper 33 is ejected as is.

On the other hand, after exposure, the automatic document feeder 1 opens the registration gate 13, discharges the original 4, closes the registration gate again, drives the feed belt 5, and starts feeding the next original 4.

In the manner described above, this apparatus automatically copies the set original 4.

"Problems to be Solved by the Invention" Here, attention will be paid to the vicinity of the regigate 13 in FIG. 5.

When the conveyance belt 12 conveys the document 4 in the direction of the arrow 16, the leading edge of the document 4 collides with the registration gate 13, and its progress is hindered. This causes the document 4 to stop at a predetermined copying position.

However, as shown in FIG. 7, for example, if the leading edge of the document 4 is curved upward, the document 4 will slip through the small gap between the registration gate 13 and the conveyance roller 12. Sometimes. Furthermore, even if the document 4 stops advancing due to the registration gate 13, the conveyor belt 12 continues to rotate for a certain period of time due to inertia. During this time, if an operator or the like accidentally comes into contact with the automatic document conveying device, the gap between the registration gate and the conveyance belt may open wide and the document may pass through. This automatic document feeder has three
This is because the document is placed with point support, so if you touch it, the automatic document feeder will tilt.

Even if the original 4 slips through the registration gate 13 in this way, this is after the registration sensor 14 has detected the feeding of the original 4.
As the feeding, exposure, etc. proceed, a blank copy is created. Moreover, this will also be counted as a normal copy.
Of course, there is also the disadvantage of wasting copy paper.

The present invention has been made focusing on the above points,
It is an object of the present invention to provide an electronic copying machine that can take appropriate measures when a document slips through a registration gate.

"Means for Solving the Problems" The electronic copying machine of the present invention is equipped with an automatic document feeder that automatically feeds a document onto a platen glass. a registration gate that stops the original at the copying position, and a first registration gate located near the registration gate and within the copying position for starting exposure and pulling out copy paper when the original is detected.
When the disappearance of the original is detected at a predetermined time or period after the output of the first detection signal until the end of exposure, a second detection signal is output to stop the exposure and the withdrawal of the copy paper. a registration sensor outputting a detection signal; controlling exposure and withdrawal of the copy paper according to the output signal of the registration sensor; and starting exposure and withdrawal of the copy paper according to the first detection signal;
and control means for immediately stopping exposure and withdrawal of copy paper in response to the second detection signal.

``Function'' In this way, when a document slips through and disappears from the platen glass, the registration sensor detects its disappearance, and the detection signal immediately stops the withdrawal of the copy paper. Waste can be kept to a minimum.

Furthermore, by stopping the operation, the operator can check the original that could not be copied.

"Embodiment" (Description of Block) FIG. 1 is a block diagram showing an embodiment of an electronic copying machine of the present invention.

The automatic document feeder 1 (indicated as ADF in the figure) has
A control unit (ADFCPU) 41 for controlling the operation is provided, and drive devices such as a registration gate 13, a registration sensor 14, a feed belt 5, a feed roller 8, and a conveyor belt 12 are connected to this.

This control unit 41 includes a ROM (not shown) that stores a microcomputer and its operating program.
(read-only memory), RAM (random
It is a module consisting of an access memory) and an I/O port.

The main unit 42 is also provided with a master CPU 43, to which a flash light source 44 and a copy paper feed roller 45 are connected.

This master CPU 43 is also a module having exactly the same configuration as the control unit 41 such as the ADF described above. Both are connected by a communication line 46. Each of them also controls other parts of each device. However, illustrations of parts not directly related to the implementation of the present invention are omitted. Further, the same parts as those in FIG. 5 are indicated by the same symbols.

This device operates as follows. FIG. 2 shows a timing chart of the detection signal of the register sensor and the signal sent by the control section.

First, conveyance is started (a in the figure), and then when the registration sensor 14 detects feeding of the document, it is turned on and becomes the first detection signal (b in the figure). It is assumed that when the document slips through and disappears, the registration sensor is turned off, and this becomes the second detection signal. When the registration sensor is turned on, the control section sends a registration signal to the master CPU via the communication line (c in the figure).

Also, when the register sensor turns off (d in the same figure),
The control unit sends a register cancel signal to the master CPU (e in the figure).

That is, in FIG. 1, the registration gate 13 is closed in response to a command from the control unit 41, the feed belt 5, the feed roller 8, and the conveyor belt 12 transport the original, and when the original is sent to the copying position, the registration sensor 14 is turned on and the master CPU
A registration signal is output to 43 via a communication line 46.

Further, as shown in FIG. 2D, when the document passes through the registration gate and the registration sensor 14 is turned off, a registration cancel signal is sent to the master CPU 43. Then, conveyance of the document is stopped.

Further, as a result, the master CPU 43 immediately stops driving the feed roller 45 for the copy paper, displays a predetermined error message on a control panel (not shown), and stops the copying operation.

In this case, the following may be considered as the operation of the master CPU 43, for example.

Example 1 A first example of operation will be explained using the flowchart of FIG.

This example shows an example in which the apparatus is operated so as not to waste any copy paper.

First, the automatic document feeder (ADF) transports the original (step). Next, it is checked whether the register sensor is turned on (step). After the registration sensor is turned on, a registration signal is generated (step). Next, wait for 300 milliseconds (step).

Typically, automatic document feeders can feed documents at a speed of 1000 mm per second or more. Therefore, in the case of the maximum size document, that is, A3 size document, the total length is about 297 mm, so it will take 300 m.
It slips through the regigate within sec.

On the other hand, the registration signal is sent to the master CPU.
Approximately 350 msec after the copy paper is received, the copy paper feed roller starts feeding the copy paper.

Therefore, after the register sensor is turned on, the process waits for 300 msec, and then immediately checks whether the register sensor has been turned off again (step).

If the registration sensor is not turned off at that time, then normal copying operation begins.

Additionally, if the registration sensor is off, a registration cancel signal is sent (step), the control section stops driving the document feed belt, and the master
The CPU stops driving the copy paper feed roller (step).

In this way, even if the original slips through, the copy paper is prevented from being sent out, so that it is not wasted.

However, the slippage of the original may occur after 300 msec has passed after the registration signal is sent. Even if this slippage occurs after the exposure has finished, a normal copy can be obtained, but
It is desirable to take some kind of measure against slippage before the end of exposure.

Example 2 In Figure 4, after sending the registration signal
This is a flowchart of the operation when a document slips through after 300 msec or more has elapsed.

First, as in Example 1, the automatic document feeder conveys the document (step). Next, check whether the register sensor is turned on (step). Then, when the registration sensor is turned on, a registration signal is sent out (step). here,
Monitor whether an exposure end signal is issued from the master CPU (step). If the exposure is completed normally, it is determined whether a replacement operation is necessary to eject the original and supply the next original (step).
In case of exchange, return to the beginning. In addition, in the case of termination, the original is ejected and the operation is terminated (step).

On the other hand, before the exposure end signal is issued, it is monitored whether the registration sensor is turned off (step), and when it is turned off, a registration cancel signal is sent out (step).

As a result, the automatic document feeder stops conveying the document, and the master CPU stops feeding out the copy paper.

At this time, copies of the missed original may be treated as abnormal copies and not counted.

As described above, the electronic copying machine of the present invention monitors whether the registration sensor is turned off again at a predetermined time or period after the registration sensor is turned on until the end of exposure, thereby preventing the document from slipping through. Detect and take appropriate measures in each case.

"Effects of the Invention" The electronic copying machine of the present invention described above can take appropriate measures immediately when a document slips through the registration gate, thereby preventing the occurrence of copy errors and waste of copy paper. Further, according to the present invention, the copying operation is started in response to the first detection signal from the register sensor, and then immediately stopped when the second detection signal is output from the register sensor. This has the advantage that the copying operation can be stopped immediately when the document slips through without delaying the operation.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the electronic copying machine of the present invention, Fig. 2 is a timing chart of its operation, Fig. 3 is a flowchart showing an example of its operation, and Fig. 4 is another example of its operation. A flowchart showing an example, FIG. 5 is a vertical cross-sectional view of an automatic document feeder suitable for carrying out the present invention, FIG. 6 is a vertical cross-sectional view of an electronic copying machine equipped with the automatic document feeder, and FIG. It is an explanatory diagram of operation. 1... Automatic document feeder, 2... Platen glass, 4... Original, 14... Registration sensor, 33...
Copy paper.

Claims (1)

[Scope of Claims] 1. In an electronic copying machine equipped with an automatic document feeder that automatically feeds a document onto a platen glass, the document fed onto the platen glass by the automatic document feeder is moved to a copying position. a registration gate to be stopped; and a registration gate disposed near the registration gate and within the copying position, which outputs a first detection signal for starting exposure and withdrawal of the copy paper when a document is detected, and also outputs a first detection signal for starting exposure and withdrawal of the copy paper; a registration sensor that outputs a second detection signal for stopping exposure and withdrawal of the copy paper when the disappearance of the original is detected at a predetermined time or period after the output of the signal until the end of exposure; and an output of the registration sensor. Controls exposure and withdrawal of the copy paper in response to the signal, starts exposure and withdrawal of the copy paper in response to the first detection signal, and starts exposure and withdrawal of the copy paper in response to the second detection signal. An electronic copying machine characterized by comprising: control means for immediately stopping the copying machine.