JPH02204253A - Electric photograph copier - Google Patents

Abstract

PURPOSE:To prevent giving damage to a long-sized document in an automatic document sender by withdrawing a stopper for stopping the document while continuingly ejecting the supply of the document when the document is detected to be long-sized. CONSTITUTION:When a copy button is pushed, in an automatic document sender 21, a carrier motor 68 is rotated and a first document is carried by a carrier roller 59, while a plunger 65 is excited and a stopper 63 is protruded. When the edge of the paper sheet passes through an optical sensor PS1, a timer built in a controller 200 is started. The controller 200 judges the document as long- sized when the passing time of the timer exceeds the specified maximum size level, and the excitation of the plunger 65 is cut. A stopper 63 is then withdrawn from the surface of a paper sheet glass board 2, while a driving motor 69 as well as a belt 53 by which a belt 53 is driven, are kept on working, whereby the long-sized document passes through a guide 66 and is ejected on an ejection board 67. When the finishing of the ejection is detected by an optical sensor PS2, the motors 68, 69 are stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic copying apparatus having a function of automatically feeding and discharging a document to be copied.

(Prior Art) When copying originals using an electrophotographic copying machine, the originals are placed one by one on the original glass table on the top of the apparatus, and the originals are replaced one after another each time copying is completed.

This task becomes very troublesome when the number of manuscripts increases.

Therefore, recently, when multiple originals are placed in a predetermined position, they are automatically transported one by one to a specified position on the original glass stand, where they are exposed, and when the exposure is completed, they are transported to the ejection position. A device called a document feeder has been developed and is used either as a built-in device in a conventional copying device or in combination as needed.

In an electrophotographic copying machine that uses this type of automatic document feeder, when you place multiple originals to be copied at predetermined positions on the automatic document feeder and press the copy button provided on the operation section of the copying device, First, the feed mechanism of the automatic document feeder operates to feed only the lowest or highest document, and then it is stopped at a specified position on the document glass by a stopper that slightly protrudes from the document glass of the copying device. do. Then,
Inside the copying machine, an optical scanning unit installed just below the document glass table moves and illuminates the document from below with a lamp.
Reflected light from the original is projected onto the photosensitive drum via a mirror and a lens. Thereafter, a document image is formed by a series of electrophotographic processes. Thereafter, the originals are automatically fed one after another and the same copying operation is repeated.

However, this type of electrophotographic copying device usually has a specified size (
For example, it is possible to copy only B5 and A4 size originals, but if you inadvertently place a larger original (hereinafter referred to as a long original) in the specified position and start copying, the long original will not be printed. Although the original is fed and transported over the glass table, even if the leading edge is stopped by the stopper, the rear part continues to be fed by the feeding roller, so the leading edge of the original is damaged or the rear part is curved, causing the document to become stuck between the feeding rollers. Otherwise, the paper may get stuck in the paper, causing a jam or damaging the original.

(Objects and Structure of the Invention) The present invention has been made in view of the above points, and has an object of preventing damage to long originals. When it is detected that the original is a long original, the stopper for stopping the original can be retracted, and the original can continue to be fed and ejected.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 diagrammatically shows an embodiment of an electrophotographic copying apparatus according to the present invention. Although automatic sorting machines (so-called sorters) are provided, these devices are not essential to the present invention.

Now, in the illustrated electrophotographic copying apparatus, an original glass stand 2 is provided on the upper surface of the main body 1, and an original is placed on the upper surface of the original glass stand 2 from below the original glass stand 2. An exposure device 3 for irradiating a document (not shown) is provided so as to be able to reciprocate in the horizontal direction.

In the center of the apparatus main body 1 is a photosensitive tram 4 which is an image carrier.
is arranged rotatably, and around this photoreceptor tram 4, in order from the top, a charging device 5, a developing device 6, and a transfer/transfer/transfer tram.
A separation device 7 and a cleaning device t8 are provided.

Further, a paper feed unit 10 is connected to the right side of the main body 1 and has an elevating base 11 that can be moved up and down by a drive source and can store a large number of recording sheets. A manual feed unit 12 is provided.

A paper feed roller 13 is provided at the top of the recording paper ejection side of the paper feed unit 1O, and the paper feed roller 13 comes into contact with the topmost paper of the recording papers placed on the elevating base 11. It is designed to be driven by a motor that does not operate. Further, in front of the paper feed roller 13 in the conveyance direction, a rapid feed prevention mechanism 14 is provided to prevent double feeding. Between this rapid-feed prevention mechanism 14 and the transfer/separation device 17 located near the photosensitive drum 4, there is a recording paper conveyance path 16 and a recording paper feeding path 16, which temporarily stops the fed recording paper, waits for it, and then restarts it. A second paper feed roller (registration roller) 15 for feeding the paper is provided. Further, a fixing unit 17 is provided on the left side inside the main body 1.

A conveying member 18 is provided between the fixing unit 17 and the photosensitive drum 4 to convey the recording paper after the transfer.

Further, a sorter 20 is provided adjacent to the left side of the main body 1, and an automatic document feeder 21 is provided at the top.

Note that 22 is a hopper that supplies toner to the developing device t6, and 23 is a stand for adjusting the height of the sorter 20 and the discharge roller 24 that discharges the recording paper from the main body l.

The paper feed unit IO is constructed as shown in detail in FIG. 2, and the elevating base 11 of the paper feed unit 10 includes pulleys 25a, 25b, and 25c.

A member 27a is attached to the stainless steel wire 26 (indicated by chain lines) stretched between 25d, 25e, and 25f.

27b, and the drive motor 28 is in the positive direction.

When reversed, the wire 26 moves up and down in the direction of the arrow. Further, a paper feed roller 13 that is movable up and down is provided on the upper main body 1 side, and in front of this paper feed roller 13 in the conveying direction, a pair of rollers 30,
A belt 32 is stretched between the belts 31 and 31, and a double feed prevention mechanism 14 is provided, which has a tension roller 33 that presses the belt 32 from above and a conveyance roller 36 that presses it from the bottom. Conveyance path 1 in front
6 is formed, and a pair of upper and lower second paper feed rollers (registration rollers) 15 are disposed at the tip thereof. In addition,
The transport roller 36 is driven by the same drive motor as the paper feed roller 13 (
(not shown).

On the other hand, a manual feed unit 12 is disposed near the paper feed roller 13 located at the top of the elevating base 11, and the manual feed plate 37 of this manual feed unit 12 is in the upright position shown by the chain line and in the illustrated position. It is possible to move between the lodging position shown by the solid line. When the manual feed unit 12 changes its manual feed plate 37 from the upright position to the collapsed position, a photocoupler (not shown) electrically detects that the manual feed mode has been set, and a lever 3B that moves together with the manual feed plate 37 (see the figure) The paper feed roller 13 is raised by pushing up the support lever 40 of the suppression roller 39 that holds the paper feed roller 13 in the lower position shown in the drawing. let me,
Therefore, when the tip 37a of the manual feed plate 37 moves from the state shown by the solid line to the state shown by the two-dot chain line, the lower surface of the paper feed roller 13 is aligned with the top surface of the tip 37a of the manual feed plate 37 shown by the two-dot chain line. They almost match.

However, when the paper feed roller 13 reaches the raised position, it moves away from the topmost recording paper placed on the top surface of the elevating base 11 and does not feed the paper, and conversely, the paper feed roller 13
The top sheet of the plurality of recording sheets placed on the manual feed plate 37 is fed.

As shown in detail in FIG. 3, the automatic document feeder 21 is located on the document glass table 2 on the top surface of the main body of the electrophotographic copying apparatus l, and on the right side is a document storage table on which the document to be copied is placed. 50 are provided.

Further, within the main body of the automatic document feeder 21, a roller 5 -m is provided at a predetermined interval above the upper surface of the document glass table 2.
1 and 52 are provided, and a belt 53 is stretched between both rollers 51 and 52, and this belt 53 is brought adjacent to the upper surface of the original glass table 2 by a pressing roller 54. Further, between the belt 53 and the document placing table 5o, first, the belt 55 is placed in a portion near the document placing table 50.
A double-feed prevention mechanism 60 is also provided here, in which a pair of rollers 56 and 57 are provided in which belts 55 are stretched, and a tension control roller 58 that presses the belt 55 from above and a conveyance roller 59 that presses the belt 55 from the bottom surface are provided. There is. This double feed prevention mechanism 60
A conveyance path 61 is formed at the front in the conveyance direction, and a pair of upper and lower feed rollers (registration rollers) 6 are provided at the tip of the conveyance path 61.
2 are arranged. The pair of upper and lower feed rollers 62 feed the original between the belt 53 and the original glass table 2. Also, an optical sensor P for detecting the passage of the recording paper is located immediately downstream of the pair of feed rollers 62.
S1 is provided.

A stopper 63 is provided diagonally at the front end of the original glass stand 2 when viewed in the recording paper feeding direction for determining the specified position of the original, and this stopper 63 is always pulled in from the glass stand surface by a spring 64. energized. on the other hand,
An actuator of a plunger 65 is coupled to the stopper 63, and when the plunger 65 is excited, the stopper 63
3 slightly protrudes above the surface of the document glass stand 2 against the spring 64. 66 is a guide for guiding the exposed original;
Reference numeral 67 denotes a document ejection table. An optical sensor PS is provided in the middle of this guide 66 for detecting a jam of a document.

Returning to FIG. 1 again, the recording paper fixed by the fixing unit 17 disposed inside the main body 1 of the electrophotographic copying apparatus is discharged by the discharge roller 24, and is transferred to each bin of the sorter 20 by the roller 70 of the sorter 20. 71, and the recorded recording paper stored in each bin 71 can be sorted left and right in the ejection direction, so that one bin can be used to sort into two.

Next, the operation of the electrophotographic copying apparatus according to the present invention will be explained.

FIG. 4 shows a part of the control circuit of the electrophotographic copying apparatus according to the present invention, and FIG. 5 is a timing chart of signals related to the control.

First, several sheets of originals are placed on the original table 50 of the automatic document feeder 21, and on the other hand, a large stack of recording paper is placed on top of the elevating base 11 of the paper feed unit 10. Keep it
At this time, the manual feed unit 12 is in the upright position shown by the chain line in FIG.

Now, when you set the operation mode of the electrophotographic copying device to multi-copy mode and press the copy button, first, the motor 68 for driving the conveying roller starts rotating and the motor 68 starts rotating. 1 The first document on the document table 50 of the document feeder 21 is conveyed by the conveyance roller 59, and the plunger 65 is excited, causing the stopper 63 to protrude. At this time, the document is prevented from being double fed by the double feeding prevention mechanism 60, moves within the conveyance path 61, and is moved to the feed roller 6.
2, it is temporarily stopped and waits.

Thereafter, the original is sent from the feed roller 62 at a predetermined timing between the belt 53 and the original glass stand 2, and is conveyed by the belt 53 driven by a belt drive motor 69 to a stopper protruding from the surface of the original glass stand 2. 63, it is stopped at a specified position. The reflected light from the document irradiated by the exposure device 3 is transmitted via the mirror group 9 to the photosensitive drum 4 charged by the charging device 5, forming an electrostatic latent image of the document image thereon, and then developed. device 16
The image is developed at , and reaches the transfer/separation device 7 .

On the other hand, the uppermost recording paper on the elevating base ll of the paper feed unit 10 is conveyed by the paper feed roller 13,
Double feeding is prevented by the double feeding prevention mechanism 14, and one sheet of recording paper is
The leading end of the paper is stopped by the second paper feed roller 15 and is on standby within the transport path 16 .

When the electrostatic latent image formed on the photoreceptor drum 4 through a series of electrophotographic processes reaches the transfer/separation device 7 as the drum 4 rotates, the recording paper that had been waiting until then is transferred to the second paper feed. It is conveyed again by the roller 15 and reaches the transfer position, is transferred and separated by the transfer/separation device 7, and then,
The image is transported by the transport member 18 to the fixing unit 17, where it is fixed, and after being fixed, it is transported into the sorter 20 by the discharge roller 24.

Sorter 20J, l: 11 recorded sheets are discharged to each bin 71 by roller 70. At this time, each bin 71 is moved up and down by a drive source (not shown), so each bin 7
1 is sequentially discharged.

When the exposure is completed, the excitation of the plunger 65 is cut off and the stopper 63 is retracted, so that the first document exposed on the document glass table z is conveyed along the guide 66 of the automatic document feeder 21 and placed on the upper surface of the ejection table 67. During this time, the second original is sent out. After that, similar operations are repeated to copy the second, third, etc. documents and sort them into bins by the sorter 20.

Next, when attempting to manually record different originals on recording paper of different sizes during the multi-sheet copying mode described above or at time t after the end of that mode, the user should move to the upright position (as indicated by the chain line in Figure 2). ) to the lying position N (shown by the solid line in FIG. 2).

With this operation, the electrophotographic copying device switches from the previous multi-sheet copying mode to the manual copying mode, and the photocopier 1
As the output of 00 changes as shown in FIG. 5(A) (for example, from "L" to "H"), the paper feed roller 13 is raised by the lever 38.

When the manual copy mode is detected in this way.

The lifting driver 28 is activated by a command from the controller 200.
is reversed for a short period of time as shown in the same figure. As a result, the elevating base 11 is slightly lowered and the paper feed roller 13 is held at the raised position by a mechanism (not shown).

Therefore, in the manual copy mode, the manual feed plate 37
When inserting the recording paper along the lines, it goes in smoothly.

After that, when the copy button is pressed, the uppermost recording paper on the manual feed plate 37 is fed by the paper feed roller 13, and the elevating base 11
Like the recording paper placed on the top surface, it is conveyed to the second paper feed roller 15 via the double feeding prevention mechanism 14, and then fed again at a predetermined timing and transferred by the transfer/separation device 7. Ru.

When the manual feed copying mode is finished and the manual feed plate 37 is returned to the upright position, the photocoupler 1 appears as shown in FIG.
Since the output of 00 changes again (from "H" to "L"), the lifting drive motor 28 is now rotated forward for a short time,
As a result, the elevating base 11 is raised to its original position.

The above is a normal copying operation when a document of a specified size (for example, B5 or A4) is used.

Next, an explanation will be given of the operation when a large original exceeding the specified size, that is, a long original is mistakenly placed, with reference to the flowchart of FIG.

This is the same in both multi-sheet copy mode and manual copy mode, but when the copy button is pressed, the automatic document feeder 21 rotates the transport motor 68 (F -1) The first document is transported by the transport roller 59. At the same time, the plunger 65 is excited and the stopper 63 protrudes (F-2).

When the leading edge of the document passes the optical sensor ps□, a timer built into the controller 200 starts in response to the change in the output. The controller 200 calculates the elapsed time of the tie 7- to the maximum specified size (for example, A4 if the specified size of the document that can be copied is 85 and A4) and the passing time (from when the leading edge of the document passes until the trailing edge thereof passes). time), it is determined that it is a long document and the plunger 6 is pressed (F-3).
Turn off the excitation of 5. As a result, the stopper 63 is retracted from the surface of the original glass table 2 (F-4). At this time, if the conveyance motor 68 and the belt drive motor 69 that drives the belt 53 continue to move without stopping, the long original is guided 66 and is discharged to a discharge table 67. When the optical sensor PS2 detects the trailing edge of the long document and determines that ejection is complete (F-7), the transport motor 68 and belt drive motor 69 are stopped (F-8), and then the copying device's display A message indicating that copying is not possible because the document is long is displayed on the panel (F-9).

In this way, the stopper 63 is retracted before the leading edge of the long original hits the stopper 63, so the leading edge of the original is not damaged, and since the long original is completely ejected, it is possible to open the device cover and remove the stopper 63. There is no need to worry about removing the .

(Effects of the Invention) As explained above, in the present invention, when the automatic document feeder detects that the document is a long document, the stopper for stopping the document can be retracted and the document can continue to be fed. Since the document is configured to be ejected, damage to the document can be reliably prevented.

[Brief explanation of the drawing]

Section 1 is a schematic diagram showing the configuration of an embodiment of the electrophotographic copying device according to the present invention, and FIG. 2 is a partial cross-sectional view of the paper feed unit and related parts of the electrophotographic copying device shown in FIG. 1. , FIG. 3 is a schematic diagram showing the configuration of an automatic document feeder used with the electrophotographic copying device shown in FIG. 1, and FIG. 4 is a block diagram of a control circuit of the electrophotographic copying device according to the present invention. FIG. 5 is a timing chart of the signals appearing in FIG. 4, and FIG. 6 is a flowchart illustrating operations related to the present invention. l...electrophotographic copying device, 2-...original glass stand, 4
...Photosensitive drum, 5--Charging device, 6--Developing device, 7--Transfer/separation, io--Paper feeding unit,
11=-・Elevating base, 12...Manual feed unit, 13
...Paper feed roller, 14...Double feed prevention mechanism, 30.3
1...Roller, 32-...Belt

Claims (2)

[Claims] (1) In an electrophotographic copying device equipped with an automatic document feeding function that automatically feeds and ejects multiple documents in sequence, a determination device for determining whether the document is a long document, and a determination device that determines whether the document is a long document; An electrophotographic copying apparatus comprising: a control means for retracting a stopper for stopping a document when a long document is determined, and for stopping the document feeding operation after the document is ejected. (2) The electrophotographic copying apparatus according to claim 1, further comprising a display means for displaying that copying is not possible when a long original is determined by the determination means.