JPS5921031B2 - Copy machine automatic document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic document feeder for a copying machine, and more particularly, to an automatic document feeder for a copying machine, and more specifically, to automatically align a copy document on a document mounting table (platen) for exposure, and to automatically eject the document after copying is completed. This invention relates to an automatic document feeder for a copying machine.

A conventional automatic document feeder of a copying machine consists of a paper feeder and a conveyor, as schematically shown in FIG. The paper feed device is provided with a paper feed roller a and a separation roller c in contact with each other, and drives the paper feed roller a in the direction of arrow A and the separation roller in the direction of arrow B via a slip clutch c.
The frictional force between the paper feeding roller a and the separation roller is greater than the frictional force of the clutch plate of the slip clutch c, and the frictional force between the separation roller and the paper, that is, the document d, is greater than the frictional force between the separation roller a and the document d. It is set smaller than the friction force of the clutch plate of slip clutch c and the friction force of the clutch plate of slip clutch c. Therefore,
When the paper feed roller a is stopped, the separation roller is also stopped, and the slip clutch c is slipping. When the paper feed roller a is driven, the frictional force between the paper feed roller a and the separation roller is greater than the frictional force of the clutch plate of the slip clutch c, so the paper feed roller a and the separation roller rotate in the normal direction.
A document d is inserted between both rollers a and b, and the separation roller comes into contact with the document d, and the frictional force between the separation roller and the document d is smaller than the frictional force of the clutch plate of the slip clutch c. Since the slip clutch c no longer slips, the separating roller rotates in the direction of arrow C to perform a separating action, and only the lowest document sheet is sent out in the direction of arrow D by the paper feed roller a. And the conveyance device is platen e
It consists of a belt gJ that is stretched around rollers f and f provided above, and is configured to convey the original sent in the direction D by the paper feeder onto the platen e and set (align) it in a predetermined position. . In this automatic document feeder, there are the following 27 methods when stopping and aligning the document at a predetermined position on the platen e.

The first method is to align the rear edge of the document with the stop position E on the rear end side of the platen e, and the second method is to align the leading edge of the document with the stop position F on the front end side of the platen e. It is something.

Which method is used generally depends on which side of the platen the scanning start point of the exposure device of the copying machine is located.

For example, when the scanning start point of the exposure device is at the stop position E on the rear end side of the platen e, alignment is performed by the first method, and when it is at the stop position F on the front end side, the alignment is performed by the second method. Conventionally, the first and second methods are carried out as follows.

That is, a micro switch h is provided in the document path in front of the platen e, and in the case of the first method, a timer is started by detecting passage of the rear end of the document by the micro switch h, and after a certain period of time, the drive of the belt g is started. In the second method, a timer is started by detecting the passage of the leading edge of the document using a microswitch h, and the drive of the belt g is stopped after a certain period of time.

In the case of the first method, the trailing edge of the document is
Since the moving distance 1 from when it is detected by the platen e until it stops at the stop position E on the platen e is small (can be made small), there is little deviation in the conveyance of the document by the belt g (due to slippage between the document and the belt). The position of the trailing edge of the document actually stopped with respect to the stop position E can be within an error range (usually ±1 mm or less) that is permissible in terms of the performance of the copying machine. However, in the case of the second method, the movement distance J from when the leading edge of the document is detected by the microswitch h until it stops at the stop position F on the platen e is equal to the movement distance 1 in the case of the first method. In contrast, since the length of the document is increased by the length of the document, the deviation in conveyance of the document by the belt g becomes large, and it is difficult to improve the accuracy of the actual stop position of the leading edge of the document relative to the stop position F.

The present invention has been made in view of the above circumstances, and its purpose is to improve the accuracy of the document stopping position in an automatic document feeder of the type that aligns the leading edge of the document with the stopping position on the front end side of the platen. To provide an automatic document feeding device for a copying machine which can efficiently feed documents.

That is, in aligning the leading edge of the original with a predetermined position on the front end side of the platen, the automatic document feeder according to the present invention first passes the leading edge of the original through a predetermined position, and then moves the original backward to bring it to the predetermined position. In order to align the leading edge of the original with the original, and to make effective use of the time it takes for the leading edge of the original to pass the specified position, move backwards, and return to the specified position, the next original is sent out at the same time as the original moves backwards. It is configured to start.

Embodiments of the present invention will be described below with reference to FIGS. 2, 3, and 4.

FIGS. 2 and 3 schematically show the configuration of the present invention.

The paper feeding device consists of a paper feeding roller 1 and a separation roller 2, and feeds original documents 4 on a paper feeding tray 3 one by one. Paper feed roller 1
A paper feeding electromagnetic clutch 6 is attached to the rotating shaft 5 of the separating roller 2, and a slip clutch 8 is attached to the rotating shaft 7 of the separation roller 2. Sprockets 9 and 10 attached to clutches 6 and 8
and the sprocket 12 of the drive motor 11 are the chain 13.
Exercise by. The paper feeding and separation operations by this paper feeding device are the same as in the conventional case described above. The paper feed roller 1
, there is a pinch roller 15 between the separation roller 2 and the platen 14 of the copying machine, and one rotation shaft 1 of this roller 15
6 has a sprocket 7 attached to it.

A conveyor belt 20 is provided on the platen 14 and is stretched around rollers 18 and 19.

A sprocket 22 is attached to one end of the rotating shaft 21 of one roller 18, and a magnetic field brake 23 is attached to the other end. The sprocket 22 includes a sprocket 26 attached to the rotating shaft 25 of the electromagnetic clutch 24 for forward rotation and a sprocket 2 attached to the rotating shaft 28 of the electromagnetic clutch 27 for reverse rotation.
9 and chain 30. A sprocket 31 attached to the electromagnetic clutch 24 for forward rotation, a sprocket 32 attached to the electromagnetic clutch 27 for reverse rotation, the sprocket 17 of the pinch roller 15 mentioned above, and the drive motor 11.
A chain 34 is extended between the sprocket 33 and the sprocket 33, as shown in FIG.

Between the pinch roller 15 and the conveyance belt 20 and in front of the conveyance belt 20, there is a micro switch MS which is activated when the leading edge of the document passes and is deactivated when the trailing edge of the document passes.
1 and MS2 are provided, respectively.

The document 4 on the paper feed tray 3 is moved by the paper feed roller 1 and separation roller 2.
is sent out by the pinch roller 15,
After activating the micro switch MSl, the conveyor belt 20
The tip slides on the platen 14 until the tip activates the micro switch MS2.

After activating the micro switch MS2, the conveyor belt 2
0, the document is reversely fed, and the leading edge of the document matches a predetermined stop position G and stops. Also, when the leading edge of the original 4 operates the micro switch MS2, the next original 4'' on the paper feed tray 3 is fed out at the same time, and at the same time the previous original 4 stops at the stop position G, the leading edge of the original 4 is placed in front of the transport bed 20. After that, the next document is exposed for copying, and the conveyor belt 2
0, the paper is ejected to the paper ejection tray 35. The operation of the present invention will be explained based on the circuit shown in FIG.

First, when the paper feed start button of the copying machine is pressed, the paper feed signal activates relays RL6 and RLl, and as contact RLl/1 closes, relay RLl self-holds.
Contact RLl/3 closes and drive motor 11 rotates.
As a result, each sprocket in Figure 2 is connected to chain 1.
Rotate by 3 and 34. When the contact RLl/2 closes, the paper feed clutch 6 is connected, and the paper feed roller 1
rotates, and the document 4 is sent out. At the same time, the right-up clutch 24 is also connected, and the conveyor belt 20 rotates in the direction to advance the document 4. When the leading edge of document 4 activates micro switch MSl, contact MSl closes and relay RL2 is activated.
is activated and the contact RL2/1 is switched to the normally open side, causing the relay RL2 to self-hold and the sheet feeding clutch 6 to be disconnected.

The document 4 is conveyed to the conveyor belt 20 only by the pinch roller 15, and after the leading edge is bitten by the conveyor belt 20, the document 4 is conveyed by the conveyor belt 20 while sliding on the platen 14. When the leading edge of document 4 passes stop position G and activates micro J switch MS2, contact MS2
switches to the normally open side, relay RL3 operates (self-holding by contact RL3/1), and contact R
Since L6/2 is closed (because relay RL6 is self-holding from the beginning), relay RL5 is activated (
Self-holding by contact RL5Z).

Then, the contact RL5/3 is switched to the normal offset side, thereby connecting the reverse rotation clutch 27 (the forward rotation clutch 24 is disconnected). <> As a result, the conveyor belt 20 rotates in the opposite direction, and the original document 4 is conveyed in the reverse direction.

At the same time, contacts RL5/4 are connected, and the paper feed clutch 6 is also connected, and the next document 47 starts to be fed.

When the reverse feed is started, the operation of the micro switch MS2 is canceled and the contact MS2 is switched to the normally closed side, and then the relay RL4 is activated and the contact RL4/1 is self-held.

At the same time, the timer T1 starts a timed operation, and after a certain period of time (the time required for the leading edge of the document 4 to move between the actuation piece of the microswitch MS2 and the stop position G), it operates and closes the contact T1/1. Switch to the normal orthostatic side. As a result, the reversing clutch 27 is disconnected, the brake 23 is activated, and the conveyor belt 20 is stopped. At the same time, contact T1/2 opens and motor 11 also stops. As a result, the leading edge of the original 4 is brought to a stop coincident with the stop position G, and is exposed for copying.

At the same time, the next document 4'', which was being sent out by the paper feed roller 1, also stops before the conveyor belt 20.At this time,
This document 4' is stopped with the microswitch MSl being activated.

That is, when the original 4'/)'-micro switch MSl is activated, the relay RL2 is activated, the contact RL2/1 is switched to the normally open side, and the paper feed clutch 6 is set to 0F.
It becomes F, so it stops. When the exposure is completed, relay RLl is activated by an automatic signal to hold itself, and contact RLl/3 is activated.
The motor 11 rotates again by the connection.

Then, the paper feed clutch 6 and the forward rotation clutch 24 are connected by the same operation as described above, and the copied original 4 is ejected to the paper output tray 35 by the conveyor belt 20, and at the same time, it is stopped in front of the conveyor belt 20. The next document 4'' that has been loaded is sent out toward the conveyor belt 20.

When the copied original 4 is ejected, the micro switch M
S2 is activated to self-hold relay RL3, and then microswitch MS2 is deactivated to self-hold relay RL4.

After that, the next document 4/ repeats the above operation (however, 2
(For the subsequent sheets, relay RL6 does not operate at all, and relay RL4 operates instead.) When a predetermined number of original documents 4 have been copied, the automatic signal is no longer input and the apparatus stops.

According to the above embodiment, the leading edge of the document is first passed through the stop position G, the leading edge is detected, and then the document is fed backwards and stopped at the stop position G, so that the document is not placed on the conveyor belt. Compared to the case where the leading edge is detected before entering the document and then stopped at the leading edge stop position, the distance the document is transported by the belt between detection and stopping can be shortened by the length of the document. The accuracy of the stop position based on conveyance deviation can be improved.

Furthermore, since the next original is being fed to the front of the conveyor belt while the previous original is being fed backwards, the time required to convey the second and subsequent originals can be shortened. As described above, in the present invention, a document sent out from a paper feeder is conveyed along the platen by a conveyance device provided on the platen, and the leading edge of the document is conveyed on the platen in the normal feeding direction of the conveyance device. In an automatic document feeder of a copying machine configured to stop at a predetermined position near the front end, a detection means for detecting the leading edge of the document is provided at a position slightly forward of the predetermined position in the normal feeding direction of the transport device. When the detection means detects the leading edge of the document, the conveyance device is driven in reverse until the leading edge of the document coincides with the predetermined position. The document is detected by a detection means located slightly ahead of the position, and based on the detection, the conveyance device is driven in reverse to bring the leading edge of the document to a stop at the predetermined position,
The document whose leading edge has been detected by the front position detection means is simply moved back slightly to a predetermined position near the front edge. Compared to a method in which the conveyor belt is moved forward by more than the length of the document and then stopped at a predetermined position near the front end of the conveyor belt in the normal feeding direction on the platen, the conveyor belt is moved forward by at least the length of the document and then stopped at a predetermined position near the front end of the conveyor belt in the normal feeding direction. It is possible to shorten the document conveyance distance until the document stops, which naturally reduces the deviation in document conveyance by the conveyance device, and therefore improves the accuracy of the stopping position.
It is possible to obtain good copies. In addition, when the detection means detects the leading edge of a document, it drives the paper feeder to feed the next document to a position where the leading edge of the document is adjacent to the conveying device. Since the document can be fed in, the document can be fed in efficiently.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is an overall view of an embodiment of the present invention, FIG. 3 is a schematic front view thereof, and FIG. 4 is a control circuit diagram thereof.

Claims (1)

[Claims] 1. A conveyance device is provided on the platen, and the conveyance device conveys the document sent out from the paper feeder along the platen, and the leading edge of the document is placed on the platen near the front end of the conveyance device in the normal feeding direction. In an automatic document feeder of a copying machine configured to stop at a predetermined position, a detection means for detecting the leading edge of the document is provided at a position slightly ahead of the predetermined position in the normal feeding direction of the conveying device, and this detection means detects the leading edge of the document. means for driving the conveying device in reverse until the leading edge of the document matches the predetermined position when the leading edge of the document is detected;
An automatic document feeder for a copying machine, comprising means for driving the leading edge of the next document to a position adjacent to the conveying device.