JPH0338177B2 - - Google Patents

Description

Control unit 41 to control An electronic copying machine comprising:

[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 operation for a large number of manuscripts, but it is also undesirable 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. 10 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.
Further, a registration sensor 14 is installed adjacent to this, which detects when the leading edge of the original 4 reaches the registration gate 13 and outputs 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. 11 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. feed belt 5 and feed roller 8
and the conveyor belt 12, the platen glass 2
is fed into the copy position above.

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. 11, the copy paper 33 is sent out from the paper feeder 34, and the flash light source is turned on at a predetermined timing to perform exposure. Thereafter, the photoreceptor 27 is developed, and this is transferred to the copy paper 33.
3 is discharged 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" In such an electronic copying machine, the air suction mechanism 5' of the feed belt is, for example, a mechanism for reducing the pressure inside a box having a large number of slits on the side in contact with the feed belt. There is. A separately provided suction pump and this box are connected by a pipe, and the suction action is controlled by opening and closing a solenoid valve inserted into the pipe.

Normally, even if the solenoid valve is normally open,
It takes a certain amount of time for the suction force of the feed belt to become sufficient.

Therefore, if this solenoid valve is opened after the main unit finishes the copying operation and a document feed start signal is issued, the timing of document feed will be delayed, and sufficient speed cannot be achieved.

On the other hand, if the solenoid valve is kept open all the time during the operation of the automatic document feeder, there is a problem in that the on-time of the solenoid becomes longer and the performance deteriorates significantly. If the solenoid deteriorates, the solenoid valve may not open sufficiently, resulting in a decrease in suction power, which may cause a delay in sending out the document and interrupt the copying process. Moreover, while the suction action is in operation, a relatively harsh noise is generated.

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 in which the operating time of a suction mechanism is minimized, the life of a solenoid is extended, and noise is reduced.

"Means for Solving the Problems" The electronic copying machine of the present invention includes an automatic document feeder that automatically feeds a document onto a platen glass, and an automatic document feeder that transports the document contained therein. This device has a feed belt that feeds the document toward the conveyance path, a suction mechanism that attracts the document to the feed belt, a document passage sensor that detects the fed document in the conveyance path, and a control unit that controls these operations. The control section is
The feed belt starts feeding by the feed belt after a predetermined time after the suction mechanism is started, and when the document passage sensor detects a document, the suction mechanism is stopped, and the next feed start time is calculated, and the suction mechanism starts feeding after a predetermined time. It is characterized by activating.

"Operation" As described above, in the electronic copying machine of the present invention,
A suction mechanism is activated a predetermined time before the document sending time by calculating the document sending time, and is stopped at the minimum necessary time after the document is sent out. A document passage sensor is provided on the conveyance path in order to determine the timing of this operation stop. With this, the above objective can be achieved.

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

In the figure, the mechanism of the automatic document feeder is number 10.
It is almost the same as that explained in the figures, and the same parts are given the same reference numerals and redundant explanation will be omitted.

In the present invention, a document passage sensor 40 is attached to the side of the guide plate 7 of the automatic document feeder that is closest to the feed belt 5.

The detection signal 40' of the document passage sensor 40 is input to the control section 41. The control unit 41 includes a CPU (microprocessor) 42, a ROM (read only memory) element 43, a RAM (random access memory) element 44, an interface (I/F) 45, and and a bus line 46 connecting between the two. An interface (I/F) 45 is a circuit for accepting input signals from sensors and the like or for outputting various control signals. The CPU 42 is provided to control the operation of each part of the device, and the ROM element 43 stores various programs for the operation. The RAM element 44 is provided to temporarily store data necessary for executing a program.

The electronic copying machine of the present invention operates as shown in FIG. 2 in principle.

First, as shown in FIG. 2a, the suction mechanism 5' is operated for 710 msec each time one document 4 is pulled out.
It operates in steps of (600msec + 110msec). and,
The waiting time t _i determined as a result of calculation by the CPU 42
and restart. This t _i time expands and contracts depending on the number of copies, etc., and is not necessarily constant.

Then, the feed belt 5 starts rotating 600 msec after the suction mechanism 5' is activated, and feeds out the document 4. FIG. 2b shows a command signal for starting rotation of the feed belt 5. The feed belt 5 then rotates for about 150 msec. As a result, the leading edge of the original 4 passes directly under the original passage sensor 40, is sandwiched between the feed roller 8 and the pinch roller 9, and is conveyed to the destination.

When the document passage sensor 40 detects the document 4, the detection signal 40' is outputted to the control section 41. This detection signal 40' is shown in FIG. 2c. The suction mechanism 5' is controlled to stop its operation at the timing of the rise of the detection signal 40' of the document passage sensor 40.

By starting the suction mechanism 5' a predetermined time (600 msec in the above example) before the rotation of the feed belt 5 starts, preparations can be made to pull out the document 4 with sufficient suction force. Further, the position where the document passage sensor 40 is installed is appropriately selected, and the suction mechanism 5' is stopped as soon as possible without affecting the feeding of the document.

In this way, the noise of the suction mechanism 5' can be reduced and the performance of the solenoid can be prevented from deteriorating.

(Calculation of t _i ) Next, a specific example of calculating the waiting time t _i from when the suction mechanism stops operating until it starts will be described.

Embodiment 1 FIG. 3 is a timing chart of the copying operation of this apparatus.

This electronic copying machine is of the flash lamp type, and its flash interval (exposure interval) is 650 m.
sec. This device can make 92 copies per minute. Further, in this embodiment, the number of copy sets, that is, the number of exposures for one document, is set to four. The number of exposures is specified by the operator using the keys on the console panel before copying, and the value is stored in the RAM of the control unit 41.
It is stored in element 44.

The flash lamp is as shown in Figure 3a.
Lights up at a constant cycle of 650msec. In FIG. 1, when a document 4 is fed onto a platen glass, a registration signal is generated from a registration sensor 14. If the flash lamp is turned on while this registration signal is being output, effective exposure is performed. The time when this effective exposure was performed is indicated by a circle in FIG. 3a.

As shown in Figure 3c, the automatic document feeder 1 (ADF) completes the replacement of the original 4 in 1200 msec, waits in the registration state until the specified four exposures are completed, and then starts its operation. Repeat.

Immediately after the completion of the fourth exposure, the next document exchange operation begins. At the beginning of this manuscript exchange work,
The feed belt 5 shown in the figure rotates for about 150 msec. The suction mechanism operates for a total of 710 msec, from 600 msec before that to 110 msec after that (Fig. 3b). From this figure, we can see that the waiting time for the operation of the suction mechanism t _i
It can be seen that satisfies the following equation.

650×5=110+t _i +600 From this, t _i =650×5−710 =650×4−60 Here, “4” is the number of exposures, and to generalize this, if the number of exposures is set as n, then t _i can be expressed as the following equation.

t _i =650×n-60... By performing calculations according to this formula, t _i can be immediately obtained.

FIG. 4 shows a flowchart of the operation.

First, the number of copy sets specified by the operator is stored in the RAM element (FIG. 1) (step). Next, turn on the solenoid valve to start the suction mechanism. (step).

Next, the document passing sensor is monitored (step).
Immediately after the document passage sensor is turned on, the suction mechanism is stopped (step). Then, it is checked whether there is a document to be sent next in the document tray (step). If there is no such document, the operation of the automatic document feeder ends, but if there is a next document, the t _i time is calculated (step), and after waiting for the t _i time, the suction mechanism is activated again.

Example 2 This example describes the waiting time for double-sided copying.
This timing chart is shown in FIG. 5 to explain the calculation method of t _i .

The operation of the flash, the interval thereof, the operation time of the suction mechanism, etc. (FIGS. 5a and 5b) are the same as those in FIG. 3, so their explanation will be omitted.

The automatic document feeder (ADF) is operable to invert the document as previously described with reference to FIG. Therefore, as shown in Figure c, after registering one side of the document, flip it over and register the other side, and then start replacing the document. .

At this time, at the same time as the document reversal process is started, the setup process for reversing the copy sheet and returning it to the transfer position also proceeds on the main unit side.
This is as explained in FIG. 10, but the time required for this is 3500 msec, and the time required for the side registration state is longer due to the waiting time.

From this figure, the following equation can be obtained.

650×10=110+t _i +600 From this, t _i =650×10−710 =650×9−60 Here, if the number of exposures is set as n, t _i can be expressed as in the following equation.

t _i =650(2n+5)−60... By performing calculations according to this formula, t _i can be obtained.

FIG. 6 shows a flowchart of the operation in that case.

The steps from step to step are the same as those shown in FIG. 4, and the explanation thereof will be omitted, but in step, the equation is calculated, and in step, the process waits for the time t _i calculated. The following is the same as in the case of FIG.

Embodiment 3 FIG. 7 shows a timing chart of processing when a copy jam occurs in the main body of the apparatus.

The operation of the flash and the suction mechanism are the same as in the previous example (Fig. 7a, b).

Here, when this device is restarted after a jam occurs, the flash will turn on at the same time as the restart, the suction mechanism will start after waiting for t _s , and the ADF will turn on at 600.
It is assumed that the setup is completed in msec and a registration signal is issued to the main unit.

Also, the number of copies set at this time is “3”.
Then, restart after a jam occurs after copying one sheet. Calculating t _s from this figure gives the following equation.

t _s + 600 = 650 x 2 t _s = 650 x 2 - 600 = 650 x 1 + 50 Here, if the number of copies set is n and the number of copies completed before a jam occurs is m, the following general formula can be obtained. can.

_ts =650(n-m-1)+50...Based on this formula, the waiting time _ts at the time of restart after jamming can be calculated.

The subsequent t _i may be determined by the method described in Examples 1 and 2.

FIG. 8 is a flowchart of the operation.

First, just before restarting, the number n of copies set and the number m of copies completed are stored in the RAM element (step). Next, check the presence or absence of registration (step). Here, if there is no registration of the document, the same process (process A) as explained in the steps from FIG. 4 is performed. If there is no document in the document tray, there is no need to prepare for transporting the next document, so the operation of the automatic document feeder is terminated after copying the document currently being registered (step).

If there is a next document, _ts explained using FIG. 7 is calculated (step), and after waiting for _ts time (step), the process returns to the beginning.

FIG. 9 shows a flowchart for a similar case of double-sided copying.

In this flowchart, the steps from step to step are the same as in the previous example. In this step, it is determined whether or not side registration is in progress. If the side is not being registered, _ts is determined in the same manner as in FIG. 8 (step). Furthermore, if the side registration is in progress, then the operation of inverting the original to the side is performed, _{so ts} is determined in the same manner as explained with reference to FIG. 5, and step calculations are performed. In this way, after waiting the determined time, the next operation is started (step).

The subsequent operation is the same as explained in Fig. 6,
The same process (processing B) is repeated from that step onwards.

If it is determined that the document is not currently being registered in the step shown in Fig. 9, and if the registration starts from the side, the process (processing B) is exactly the same as that shown in Fig. 6. When starting from the ration, the process goes through the same process (process A) as the steps from step to step in FIG. 4, and then enters process B.

"Effects of the Invention" The electronic copying machine of the present invention described above can reduce the operation time of the suction mechanism to the shortest time required for high-speed conveyance, prevent deterioration of the suction mechanism, and reduce noise. Can be done.

Further, according to the present invention, the next feeding start time is calculated based on the time when the document passing sensor detects the document, and the suction mechanism is activated a predetermined time before that time, so the suction mechanism is activated before the document is sent out. There will be no delay in sending out the original, and
High-speed conveyance is possible even under conditions where the document sending time may change.

Further, according to the present invention, the suction mechanism is stopped when the document passage sensor detects the document, so even if conditions such as the document size change, the suction mechanism is always set at the time that minimizes the operation time of the suction mechanism. can be stopped.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the electronic copying machine of the present invention, FIG. 2 is a timing chart explaining its operating principle, and FIGS. 3, 5, and 7 are:
Explanatory drawings for determining the waiting time t _i of the suction mechanism, FIGS. 4, 6, 8, and 9 show flowcharts of the operation. FIG. 10 is a longitudinal cross-sectional view of an automatic document feeder suitable for carrying out the present invention, and FIG. 11 is a longitudinal cross-sectional view of an electronic copying machine in which the automatic document feeder is installed. 1... Automatic document feeder, 2... Platen glass, 4... Original, 5... Feed belt, 5'...
...Suction mechanism, 40...Document passage sensor, 41...
control section.

Claims (1)

[Claims] 1. In an electronic copying machine equipped with an automatic document feeder 1 that automatically feeds a document onto a platen glass 2, the automatic document feeder 1 directs the accommodated document 4 toward a conveyance path 7. a suction mechanism 5' that causes the document 4 to be attracted to the feed belt 5; a document passage sensor 40 that detects the document 4 fed out by the feed belt 5 in its conveyance path 7; and the suction mechanism 5. ′ starts feeding by the feed belt 5 after a predetermined time after starting, and when the document passing sensor 40 detects the document 4, the suction mechanism 5′ is stopped, and the document passing sensor 40
The feed belt 5 is configured to calculate the next feeding start time based on the time when the document 4 is detected by the feed belt 5, and to start the suction mechanism 5' a predetermined time before that time.
The operation of the suction mechanism 5' and the document passage sensor 40 is