JPH0472248A - Automatic copy feeding device - Google Patents

Abstract

PURPOSE:To discriminate a copy size correctly by making a detecting signal of no copy void when it is detected again that there is a copy, in a specific time, after it was detected that there was no copy by a copy detecting means, and continuing the discrimination of the copy size, by a size discriminating means. CONSTITUTION:When the size of a copy is detected, it is detected that there is no copy by using punched holes and the like. And after that, when it is detected again that there is a copy, in a specific time, the detecting signal of no copy is made void, and the discrimination of the copy size is continued by a discriminating means 30. As a result, whereever the punched holes may be, a correct size can be discriminated without mistaking the punched holes for the rear ends of the copies.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic document feeder that feeds a document to a predetermined position.

E. Prior Art Some ML image processing apparatuses such as copying machines are equipped with an automatic document feeder that feeds a document to a predetermined position such as an exposure position.

In such an automatic document feeder, an optical document detection sensor detects the leading edge and trailing edge of the document to be fed, and the feeding pulse is detected while the optical sensor detects the presence of the document. The document size is detected by the number or time, and the document size is automatically selected based on the detected document size, and the amount of transport until reaching a predetermined position such as the exposure position is controlled. There is something.

Incidentally, such an automatic document feeder is sometimes loaded with a document having punched holes for filing at the leading and trailing edges, such as computer printer paper.

However, when a document with such punched holes is input, the optical document detection sensor that detects the leading and trailing edges mistakenly recognizes the punched hole as the trailing edge of the document, and the document size is incorrect. This may lead to erroneous judgments. Further, in the case where the amount of conveyance to a predetermined position is set after the trailing edge of the document is detected, the set amount of conveyance is insufficient, and there is a problem that the document cannot reach the predetermined position.

Therefore, as disclosed in Japanese Patent Application Laid-open No. 59-78044, by stopping the inspection operation of the document detection sensor for a certain period of time after detecting the leading edge of the document, the punched hole portion can be mistakenly recognized as the original SaW. There are some things I tried not to do.

[Problem to be solved by the invention 1 However, in the technology disclosed in the above publication,
As shown in the waveform diagram of FIG. 5 (1), if the timing t at which the original detection signal SN output from the original detection sensor is turned off by the punched hole occurs within a certain time of 1111T, then the punched hole However, as shown in Figure 5(b), if the punch hole turns off timing t exceeds a certain time T, The S portion of the hole is mistakenly recognized as the rear edge of the document.

That is, in the technique disclosed in the above-mentioned publication, there is a problem that the size of the document may be erroneously determined if the positions of the punch holes are irregular. Further, in a method in which the amount of conveyance to a predetermined position is set after detecting the trailing edge of the document, there is a problem that the amount of conveyance is insufficient by the size of the punch hole, making it impossible to accurately reach the predetermined position.

The present invention was made to solve such problems,
It is an object of the present invention to provide an automatic document feeder that can prevent erroneous size determination when feeding documents with holes such as punch holes that are smaller than a specific size.

Another object of the present invention is to provide an automatic document feeder that eliminates insufficient conveyance due to punch holes or the like when conveying a document to a predetermined position by detecting the trailing edge of the document.

[Means for Solving the Problems 1] In order to achieve the above object, the present invention includes a feeding means for feeding a document to a predetermined position, a document detection means for detecting the presence or absence of a document being conveyed to the predetermined position. and a size determining means for determining the document size based on the detection output of the document detecting means, and the size determining means detects the presence of the document again within a certain period of time after the document detecting means detects that there is no document. In this case, the document size detection signal is disabled and the document size continues to be determined.

Also,! 11. a feeding means for feeding a document to a predetermined position; a document detecting means for detecting the presence or absence of a document to be conveyed to the predetermined position; a feeding control means for setting data regarding a conveyance amount and causing the feeding means to convey the original according to the data; When the presence of a document is detected again, the data regarding the conveyance amount is reset.

1 Effect 1 When detecting the document size, if the presence of a document is detected again within a certain period of time after detecting the absence of a document by a punch hole, etc., the original 8II no detection signal is invalidated and the document size determination is continued. Therefore, no matter where the punch hole or the like is located, it is possible to determine the correct size without misrecognizing it as the rear end.

In addition, when transporting an IfL document to a predetermined position, after detecting the trailing edge of the document using a bunch of holes, etc., if the presence of the document is detected again within a certain period of time, the data regarding the amount of conveyance is reset, so that punch holes, etc. Regardless of the position, it can be accurately transported to a predetermined position without causing insufficient transport.

[Example] Hereinafter, the present invention will be explained based on Examples.

FIG. 1 is a sectional view showing one embodiment of the overall configuration of the conveyance mechanism of the automatic document feeder of the present invention.This automatic document feeder W11 can be roughly divided into two types: A feeding section 3 that feeds originals one by one, a transport section 4 that transports the originals fed one by one to a predetermined position on the platen P, and a transporting section 4 that ejects the originals after image processing or turns them over and returns them to the platen P. It consists of an inversion discharge section 5 that guides the document to a predetermined position, and a discharge tray 6 on which the discharged document is placed.

The paper feed section 3 includes a pickup roller 7 and an empty sensor 8.
, a separation roller 9, a registration sensor 10, a pickup roller 7, and a motor M1 as a power source for the separation roller 9.The pickup roller 7 picks up several documents from the bottom of the document placed on the paper feed tray 2. The documents are taken out one by one, and only the lowest document is separated by the separation roller 9 and sent to a space 11 having a large loop margin. Here, outside! The document whose direction has been changed along the γ-id plate 12 passes through the straight guide section 13 and is directly delivered to the nip between the registration roller 14 and the pinch roller 15 of the conveyance section 4.

The conveyance section 4 includes the reno roller 14 and the pinch roller 15, a wide conveyance belt 16, and the conveyance belt 16.
a driving roller 17 and a driven roller 18 that rotationally drive the
It consists of a plurality of pinch rollers 19 that stretch the conveyor belt 16 over the top surface of the platen P, and a registration roller 14.
The document fed to the entrance of the platen is sent out in the direction of the platen P by the rotation of the registration roller 14 while being pressed between the registration roller 14 and the pinch roller 15, and starts rotating at the same time as the registration roller 14. It is conveyed onto the platen P by a conveyor belt 16. Note that an electromagnetic clutch G is interposed between the rhenostroller 14 and the conveyor belt drive motor M2, so that the rhenostroller 14 stops rotating while the conveyor belt 16 is rotating.

At this time, the Renost sensor 10 remains on until the trailing edge of the document is sent out from the registration sensor 10, so the control section (not shown) starts rotating the Renost roller 14 and the drive roller 17, and from the timing the registration sensor 10 detects the passage of the trailing edge of the document. The number of pulses applied to the motor M2, which is the power source for the drive roller 17 and the registration roller 14, is counted until the timing is turned off, and the document size L1 is classified into regular document sizes based on the count value. Then, the motor M2 is stopped when a pulse corresponding to a phase difference of 10 from the position of the registration sensor 10 to a predetermined position A on the platen P is applied to the motor M2.

As a result, the original is set at a predetermined position A on the platen P.

Next, the reversing and discharging unit 5 includes a reversing roller 20, driven rollers 21m and 21b that are in pressure contact with the reversing roller 20, a switching claw 22 that transports the document reversely in the direction of the conveyor belt 16 with the front and back sides reversed, a paper discharge sensor 23, and a reverse It consists of a sensor 24 for determining the stop timing during feeding, a paper ejection roller 25, and a motor M3 as a power source for the reversing roller 20. The discharged document is conveyed in the discharge direction by the inverter 220. At this time, if the switching claw 22 is as shown, the document is transferred to the paper output tray 6 by the # paper roller 25.
is discharged. However, when the switching claw 22 is switched to the reverse side, the sheet is guided toward the driven roller 1811 of the conveyor belt 16, and is set at the predetermined position A on the platen P again by the reverse rotation of the conveyor belt 16.

FIG. 2 is a block diagram showing the configuration of a control unit that controls the conveyance of a document in the present invention, and specifically, it is configured by a microcomputer 30. As shown in FIG.

In FIG. 2, the micro combinator 30 includes an empty sensor 8, a registration sensor 10, and a discharge sensor 23.
In addition to inputting each sensor output signal of the sensor 24 for detecting stop timing, there is also a 70 pulse φ1 that serves as a reference for the pulses PMI to PM3 applied to the motors M1 to M3.
．． φ2 is input. Also, as an output signal, the paper feed section 3t! 3 minutes @ Motor M1 for rotating the a-29 etc., motor M2 for rotating the conveyor belt 16,
Application pulses PMI to PM3. to the motor M3 for rotating the reversing roller 20. Motor M to registration roller 14
Registration roller rack for transmitting the rotation of 2? ? An on signal RCL to the switch G, a drive signal SD to a solenoid (not shown) for switching the switching claw 25, and the like are output.

Also, inside the microcomputer 3o, there is a size N
A register SZ in which a final valid size value is set, a counter CN1 for size determination, a counter CN2 for detecting the size of punch holes, etc., a transport A pulse STP that determines the transport amount to a predetermined position A. A counter CN3 is provided to set the number of .

Below is the predetermined value of 1m from size detection! The operation of the above structure will be explained in accordance with chart 70 in FIG. 3 showing the conveyance control means up to A.

First, when the leading edge of the document taken out one by one from the paper feed tray 2 is detected by the Renost sensor 10, the motor M1
is rotated for a certain period of time to form a slack in the original document by the registration roller 14 to prevent skew. Thereafter, the motor M2 starts rotating and the electromagnetic clutch G is turned on. As a result, the document that has been looped at the position of the registration roller 14 is conveyed toward the buffer plate P in synchronization with the rotation of the motor M2. In other words, the original platen P
Therefore, prior to the start of feeding, the counters CNI and CN2 in the microcomputer 30 are cleared to 0, and the counting operation of the size detection counter CNI is permitted (step S1). While the registration sensor [0] detects the presence of a document, the count value of the ONN fluorometer counter CNI of 70 pulses to the motor M2 is updated (steps 83 to S5). Then, when the trailing edge of the document passes the position of the Renost sensor 10 and the registration sensor 1o is turned off, the count value of the counter (,Nl) is assigned to the register SZ.At the same time, the counter that detects the size of the hole Enable counting operation of CN2 (step S
6) At this time, CNI counting continues.

Next, since the rear layer of the original is detected, the transport pulse ST is applied to transport the original to a predetermined position and stop it.
Set the number of P to counter CN3, counter CN3
After permitting the down-count operation (step S7), the phase separation in which the registration sensor 1o is off is measured by counting 70 pulses to the motor M2 with the counter CN2 (steps S8 to 5IO).
In other words, it is possible that the reason why the registration sensor 1o turned off in step s5 was due to the passage of a punched hole, etc. By counting , the period during which the registration census o is off is counted by the counter CN2 as the size of the punch hole. Then, the count value is compared with a predetermined value MSK in step Sll, and when the count value of the counter CN2 becomes equal to the predetermined value MSK, in step s5, the cause of the Renost sensor O being turned off is the punch hole. It is recognized that it was the true rear end and not due to
The value of the counter CNI set in the register SZ is determined as the valid value of the document size (step s12).

However, if the registration sensor 1o is turned on again before the count value of the counter CN2 becomes equal to the predetermined value MSK, the reason why the registration sensor 10 is turned off in step s5 is that a punch hole smaller than the predetermined value MSK has passed. Then, only the counting operation of counter CNI is continued, and counter CN2 . Counting operation of CN3 is prohibited. Then, [detection of the document size is continued by the counter CNI until the registration sensor 1o is turned off again.

” Thereafter, if the Renost sensor 10 has been off for a period longer than the predetermined value MSK due to the passing of the true trailing edge of the document, the count value of the counter CNI up to that point is determined as the valid value of the document size. do. And counter CNI.

The count operation of CN2 is prohibited (Step 513), and the number of transport pulses STP preset in counter CN3 is counted down every time the 70 pulses to motor M2 are turned on, and when the count value reaches rOJ, the document is stopped at the bottom. The process is performed and the rotation of motor M2 is stopped (steps 814 to 516).

This causes the document to stop at a predetermined position.

In this stop processing, if there is a punched hole that is less than the predetermined value MSK, the process returns from step Sll to step S3 and the number of conveyance pulses STP is set again in step S6. The document is moved to a predetermined position A by the number of transport pulses STP determined from the true trailing edge of
It will be transported to.

Therefore, according to this embodiment, as shown in the waveform diagram of FIG. 4, if the period TH during which the document detection signal SN of the registration sensor 1o is turned off due to a punch hole or the like is less than the predetermined value MSK, During this period TH will be ignored. Therefore, no matter where the punch hole is located on the document, if it is smaller than the predetermined value MSK, it will be ignored, and by detecting the true trailing edge of the document, the size of the document can be determined and the predetermined position A The setting operation of the number of transport pulses up to .

Note that in the above embodiment, the determination of the document size and the predetermined value jlA
Although the description has been made of a system having both of the transport controls described above, it goes without saying that the system can also be applied to a case where only one of the transport controls is provided.

[Effect of the invention 1] As is clear from the above description, in the present invention, when detecting the document size, if the presence of the document is detected again within a certain period of darkness after detecting the absence of the document by punch holes etc., it is determined that there is no document. Since the document size determination is continued with the detection signal invalidated, no matter where the punch hole or the like is located, it is possible to determine the correct document size without misrecognizing it as the trailing edge.

In addition, when conveying a document to a predetermined position, after detecting the trailing edge of the document using a punch hole, etc., if the presence of the document is detected again within a certain period of time, the data regarding the conveyance amount is reset, so that the punch hole, etc. No matter where the paper is placed, it can be accurately conveyed to a predetermined position without causing insufficient conveyance, and it is possible to eliminate paper jams caused by insufficient conveyance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the transport mechanism of the automatic document feeder of the present invention, FIG. 2 is a block diagram showing the configuration of the control section, and FIG. 3 is a diagram showing the determination of document size and transport to a predetermined position. 7a-chart showing the control procedure, Figure 4 is a waveform diagram to explain that punched holes are ignored, and Figure #S5 is a waveform diagram to explain problems when punched holes are present in the conventional device. It is. 9... Separation roller, 10... Renost sensor, 14
... Registration roller, 16... Conveyance belt, 30.
...Microcomputer, CNI, CN2. CN3...Counter, SZ...Register

Claims (4)

[Claims] (1) A feeding means for feeding a document to a predetermined position, a document detection means for detecting the presence or absence of a document being conveyed to the predetermined position, and a detection output from the document detection means from the leading edge to the trailing edge of the document. In the document feeder, the size determining means detects the presence of the document again within a predetermined period of time after the document detecting means detects the absence of the document. An automatic document feeder characterized by disabling a blank detection signal and continuing to determine the document size. (2) a feeding means for feeding a document to a predetermined position; a document detection means for detecting the presence or absence of a document being conveyed to the predetermined position; a feeding control means for setting data regarding the amount of transport to the position and causing the feeding means to transport the original according to the data; and the feeding control means, after the original detecting means detects the trailing edge of the original; An automatic document feeder characterized in that when the presence of a document is detected again within a certain period of time, the data regarding the conveyance amount is reset. (3) The automatic document feeder according to claim 2, wherein the data determines the time required to reach a predetermined position. (4) The automatic document feeder according to claim 2, wherein the data is a number of pulse signals corresponding to the amount of conveyance until reaching a predetermined position.