JPH05330692A - Automatic document feeding device - Google Patents

Abstract

PURPOSE:To perform document jam recovery work safely by performing the home alignment of a nudger roller at the beginning of document jam generation. CONSTITUTION:Feed mechanism for feeding documents from a sheet placing part 20, is provided with a built-in nudger roller 38 having the discontinuous part of the curved face. When the jam of documents fed in by this nudger roller 38 is detected by a controller, a rotatory-driving command for rotating only the nudger roller 38 clockwise or counterclockwise is outputted to a feed motor driving means, and the nudger roller 38 is driven and stopped into its home position. A cover 30 is then opened to remove the jammed documents, and the cover 30 is closed to resume the job. That is, the document jam recovery work is performed after terminating the home alignment of the nudger roller 38, so that an operator's fingers are prevented from being caught between the nudger roller 38 and a shoot at the time of opening/closing the cover 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder in a recording apparatus such as a copying machine, a printer or a facsimile, and more particularly to an automatic document feeder for controlling home position stop of a najar roller for feeding originals one by one. Regarding

[0002]

2. Description of the Related Art Recently, with the development of high precision, high speed, miniaturization and the like of a recording apparatus, as a means for efficiently performing various job functions, an automatic document feeder has been used. The functions and performance are improved. Various types of automatic document feeders have been put into practical use, but basically, the document is automatically fed, set on the platen glass, and then ejected after the reading is completed. It is prepared as an option so that it can be selectively equipped. This device feeds the originals set on the sheet mounting table one by one at the timing of image processing from the original entrance through the sheet conveyance path, conveys them on the platen glass by an endless belt, and after the original image is read, the ejection conveyance path is set. It is to be discharged to the document discharge tray via the.

By the way, the automatic document feeder is roughly divided into a tray section for placing originals before and after processing, a paper feeding section for feeding the originals, a registration section for stopping the originals at a predetermined position on the platen glass, and a post-processing section. It is configured by a document discharge unit that removes the document from the platen glass.

Here, an apparatus configuration for feeding the originals one by one will be described. The document entrance is located in the carry-in section for feeding the documents, and is provided with a nudger mechanism for feeding the set documents one by one. In the conventional nudger mechanism, a lower roller is rotatably supported by a fixed shaft, and the shaft of an upper roller facing the lower roller is provided so as to be movable in the vertical direction, and a lower rotating belt is provided. Which has an upper roller disposed to face it, or JP-A-60-26.
As proposed in Japanese Patent No. 551, there is known one provided with a sheet feeding roller (najar roller) having a portion where a curved surface is interrupted.

In the automatic document feeder having such a nudger mechanism, when a document is jammed in the device, the device is stopped and the user is notified by the document jam display.
After that, open the paper feed cover that covers the top of the carry-in section, the top cover that is provided with the sheet stacking section that covers the registration section (belt section), or the document discharge section cover that covers the document discharge section and remove the jammed document. Removed, closed cover and restarted job.

By the way, in the case of a najar mechanism having a najar roller having a portion where the curved surface is interrupted, at the regular stop position of the najar roller, that is, at the home position, the portion where the curved surface is interrupted is parallel to the chute, and the najar roller moves from the chute. It does not project. Therefore,
If a document jam occurs, the device will stop immediately.
The Najara roller stops at a position other than the home position. After that, when the cover is opened to recover the jammed document, the signal is sent from the interlock sensor to the safe side so that the drive system of the apparatus is not operated.
Then, the work of removing the jammed document is performed. When this recovery is completed and the cover is closed, the home position operation of the nudger roller is performed on the condition of the input signal from the interlock sensor.

[0007]

However, in the case where the side on which the najar roller is arranged is provided with a paper feed section cover which can be opened and closed by putting a finger on the hand, the finger is extended to the back side of the paper feed section cover to feed the paper. There is a risk of closing the part cover. When such a closing operation is performed, in the home position adjusting operation of the nudger roller, the driving of the nudger roller is started before the finger is released from the paper feed unit cover, and the finger is caught by the nudger roller. Further, when the document is sandwiched in the nip between the feed roller and the retard roller (splitting roller), it is difficult to remove the document. SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeder capable of performing a home position adjustment of a nudger roller at the initial stage of occurrence of a document jam and safely recovering a document jam.

[0008]

In order to achieve the above object, the present invention provides a feed mechanism for feeding a document from a sheet placing portion, and a najar roller having a curved discontinuous portion incorporated in the feed mechanism. In an automatic document feeder including a home position sensor that detects the position of the nudger roller and a drive unit that drives the nudger roller to the home position in response to a signal from the home position sensor, a document jam in the sheet conveyance path is prevented. It is provided with a detecting means and a controller for outputting to the nudger roller driving means a rotation drive command for adjusting the nudger roller to the home position by a document jam detection signal.

Further, in the case of a feed mechanism including a feed roller, a nudger roller, and one driving means for driving the roller, the feed roller is driven through a one-way clutch for rotating only in the sheet feeding direction. It is in. Further, in the case of the feed mechanism provided with the one-way clutch, the home position of the nudger roller is adjusted by the reverse rotation drive when a document jam occurs. Further, in the case of a feed mechanism provided with a clutch for separating the feed roller from the driving means, when the document is jammed, the clutch is operated to perform home position alignment of the nudger roller by forward rotation drive.

[0010]

When a document jam is detected, the controller issues a rotation drive command to the feed motor drive means for rotating only the nudger roller in the forward or reverse direction, and drives the nudger roller to stop the nudger roller at the home position. Then open the cover to remove the jammed document, close the cover, and restart the job. That is, since the work for recovering the jam of the document is performed after the home position adjustment of the najar roller is completed, the fingers of the hand are not caught between the najar roller and the chute during the opening / closing operation of the cover. In particular, when the home position of the nudger roller is reversed, the document sandwiched by the nip between the feed roller and the retard roller is returned, and the jammed document can be easily removed. In addition, the stop control of the home position of the nudger roller when a document jam occurs realizes the function of the automatic document feeder.Therefore, a document jam is detected using sensor outputs such as a registration sensor and a document ejection sensor that are necessary for control. Since the rotation driving command of the feed motor is output according to the document jam detection signal, it can be dealt with by changing the software of the controller.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is applied to a copying machine, and is configured by combining a base machine with additional devices such as a double-sided automatic document feeder and a sorter. FIG. 1 shows a sectional structure of an automatic document feeder according to the present invention. In the copying machine, as shown in FIG. 6, a double-sided automatic document feeder (ADF) 2 is mounted on a base machine 1, and the base machine 1 responds to a job set by a console panel (not shown). Controls the mechanical part including the attached device,
It is configured to perform image processing on a sheet of a specified size supplied from the sheet tray 3 based on the image information read from the document sent by the ADF 2, and then execute the sheet discharging process.

Explaining the image processing section, a charge corotron 5, a developing device 6, a transfer corotron 6 and a cleaning device 8 are arranged on the outer periphery of the photosensitive drum 4. In this copying machine, as the photosensitive drum 4 rotates in the direction of the arrow, the photosensitive drum 4 is uniformly charged by the charge corotron 5, and then exposed to light at the exposed portion 9 to form an electrostatic latent image. It A light image of a document placed on a platen glass 10 arranged on the upper surface of the base machine 1 is made to enter the exposure portion 9. For this purpose, for example, a light lens system optical reader 11 is provided.

The photosensitive drum 4 on which the electrostatic latent image is formed is then developed by the developing device 5. Here, the toner image formed on the photosensitive drum is transferred onto a sheet by the transfer corotron 7, thermally fixed by the fixing device 12, and discharged.
On the other hand, the photosensitive drum 4 is cleaned by the cleaning device 8 and reused.

The ADF 2 includes a sheet placing section 20 provided on an upper surface of a top cover 20a which is openably and closably supported by a hinge 21, a sheet feeding section 30 which automatically conveys and processes originals according to various job modes, A document registration unit 40 (hereinafter referred to as “document registration unit”) for positioning a document on a platen glass 10 (hereinafter referred to as “platen”) for reading a document image by an optical reading device of the base machine 1 and image processing. Subsequent originals are output tray 51
It is composed of a document discharge section 50 for discharging the document.

As shown in FIG. 2, the paper feed unit 30 feeds a document D set on the sheet mounting table 20 from a document entrance to a registration roller 31 (hereinafter referred to as a "registration roller"). Transport path 32, manual feed port 3
3 to the registration roller, a manual feeding path 34, a feed path 35 for feeding the original onto the platen at a predetermined timing, and a double-sided original processing (duplex mode). A duplex transport path 36 is provided for transporting the pulled-in document from the rear end thereof by a duplex roller in the reverse direction and to the upstream side of the registration roller. A paper feed unit cover 30a is provided on the upper portion of the paper feed unit and is opened and closed by hanging a finger on the sheet mounting table side.

The feeding / conveying path 32 is provided with a feeding mechanism for feeding the originals D one by one. This feed mechanism is a najar roller 3 having a shape (half-moon shape) having a discontinuous portion in which a curved surface is interrupted for sequentially feeding the document D stacked on the sheet mounting table 20 from the document at the bottom.
8. A feed roller 39A for feeding the document inserted by the nudger roller and a chute, which is fixed to the chute, separates the documents fed by the nudger roller 38 into the document fed by the nudger roller 38 and conveys them one by one. It is provided with a retard roller 39B.

An ingate 37 for stopping the leading edge of the original when setting the original is provided on the sheet loading table side of the original entrance, and the originals stopped by the ingate 37 are automatically inserted one by one. A najar roller 38 of a feed mechanism is provided. The ingate 37 operates the ingate solenoid in response to a signal from the document set sensor S1 to perform a vertical movement such that the document entrance is projected or retracted. The ingate solenoid is turned on when the original sensor of the tray detects the first original, and the ingate 37 is projected to the original entrance to receive the leading edge of the original, and is turned off after a predetermined time has elapsed or when the ADF start signal is received. It is operated to immerse it from the document entrance, allowing continuous feeding of documents. Najara roller 38
The home position is controlled by the signal from the home position sensor S2.

FIG. 3 shows the construction of the feed mechanism excluding the retard roller 39B. In FIG. 3, one shaft end of the nudger roller 38 is connected to the feed motor 44 via the timing belt 45, and the gear 46A and the position detection plate 47 are attached to the other shaft end. A detection unit 48 for detecting the rotation of the position detection plate 47 is provided. The position detection plate 47 and the detection unit 4
The home position sensor S2 is constituted by 8. A gear 46C is attached to the shaft end of the feed roller 39A, and is connected to the gear 46A via an intermediate gear 46B. In addition, the feed roller 39A is provided with a one-way clutch 39B so that the retard roller 39B performs a judgment operation.

In the middle of the pull-in transport path 35, there is provided a registration gate 41 for switching from the pull-in transport path to the duplex transport path 36 for reversing the original in the original register section 40 and setting it on the platen in the duplex mode. .. The registration gate 41 is a plate-shaped member having a substantially triangular cross section, and has a rotation axis parallel to the rotation axis of the belt drive roller 42 and a width substantially equal to that of the platen 10. During double-sided document processing, the registration solenoid is energized under the condition that the first processing surface of the document is in the registration section, and the operation of switching the conveyance path of the registration gate 41 is performed.

The document registration section 40 is provided with a belt 43 driven by a belt drive roller 42 which uses a belt motor as a power source. The original reaching the registration roller 31 is related to the distance between the registration roller 31 and the registration position (hereinafter referred to as “registration position”) on the platen 10 in accordance with the sheet conveyance on the base machine side and the operation timing of the optical reading device. The belt 43 is driven only for a predetermined time, and the original is conveyed by the cooperation of the registration roller 31.
The trailing edge of the original is stopped at the registration position at the end of the platen on the original loading side (including the vicinity).

A registration sensor S3 (hereinafter referred to as "registration sensor") for detecting the front end and the rear end of the original document and a size sensor (for detecting the original width) of the original are provided in the sheet feeding section 30 in the feeding path near the registration roller 31. (Not shown)
Further, a manual document sensor S4 for detecting a manual document is provided in the manual feed path 34.

The document discharge section 50 is provided with a document discharge sensor S6 for detecting the document sent from the document registration section 40 and a document discharge roller for conveying the document, and a belt motor and a document discharge are issued by a document discharge command. The motor is driven to send the processed original sent from the original register section 40 to the discharge tray 51. This document discharge section is provided with a document discharge section cover 50a for maintenance. The apparatus of the present embodiment is provided with an interlock switch on each cover, and the operation of holding the apparatus in a stopped state by a signal from the interlock switch is performed by opening / closing the cover when recovering a document jam. I am making it.

Next, the home position alignment control of the najar roller will be described. FIG. 4 shows a block configuration of home alignment control of the najar roller. The feed motor controller 100 feeds a document after a lapse of a predetermined time from a registration sensor signal output by detecting the front end of the document or an OFF signal of the belt motor (a first document feeding operation after the remaining document discharge processing). Signals input at various timings required for turning commands and home alignment control (hereinafter "timing signals")
In addition to outputting a motor reverse rotation command or a motor forward rotation command, a motor stop command for stopping the najar roller at the home position is output based on the rotating najar roller position signal.

The timing signal is a power-on signal that is issued after the power-on sequence of the control circuit board of the base machine and the additional device, and a belt motor that is issued a predetermined time after the registration sensor detects the front edge of the document. ON signal, a document set signal issued when a document is set on the document tray, and a sheet jam detection signal issued when the document is jammed in the apparatus. Here, for the sheet jam detection, the registration sensor S3, the manually fed document sensor S4 and the document discharge sensor S6 are used.
Judgment is made at the timing when the document reaches or passes these sensors.

The feed motor drive circuit 101 executes a pre-programmed motor drive during reverse rotation by a reverse rotation command or a stop command from the controller 100,
The najar roller 38 is adjusted to the home position by performing control to rotate or stop the feed motor 44 in the reverse direction. In this case, since the feed roller 38A has a one-way structure in which only the forward rotation is performed, the feed roller is in the idling state at the time of reverse rotation of the najar roller, and friction with the retard roller does not occur.

Further, the pre-programmed motor drive at the time of normal rotation is executed by the normal rotation command or the stop command from the controller 100, and the feed motor is controlled to rotate normally or stop to adjust the najar roller to the home position. Home alignment by this forward rotation,
Since it is performed at the same time when the document is pulled in, it is performed with the document interposed between the feed roller and the retard roller, and abrasion of the retard roller is prevented. Here, the home positioning operation of the nudger roller of the feed motor controller will be described with reference to FIG.

When the power of the base machine is turned on and the power-on sequence of the ADF controller is completed, various timings are judged. First, when the power-on signal is output, the operation of the belt motor is determined, and when it is ON for the remaining document discharge processing, a reverse rotation command for home position alignment is issued, and the motor is driven in reverse to drive the najar roller. Only reverse rotation (S1). At this time, the home position signal of the home position sensor is used to check the home position of the najar roller (S2). When the najar roller is rotated to the home position, the motor is stopped (S3), and the home position of the najar roller is initially adjusted. Next, when the start button is pressed (S4), the feed motor is driven in the forward direction to rotate the nudger roller in the forward direction to feed the document set on the sheet mounting table. Since the feed roller is also driven in the normal rotation by the feed motor, the document fed by the nudger roller is conveyed to the registration roller by the feed roller and then drawn into the document registration section (S5).

During this period, it is judged that the document is jammed (S6), and if there is no document jam, it is judged whether the feeding is completed based on the signal from the registration sensor (S7). When it is determined in step S6 that the document is jammed, a home position adjusting operation of the nudger roller when the document is jammed is performed (S8). When the home alignment of the najar roller is completed, the feed motor is stopped (S9).
After that, the signal from the document sensor S1 is checked (S1
0), if there is no next original, the job ends. If there is a next original, the process returns to step S5 to continue feeding the original.

When a document jam occurs, the document jam is determined in step S6, the feed motor is rotated in the reverse direction, and only the nudger roller is driven in the reverse direction to perform home alignment (S11). Next, the signal from the home position sensor is checked (S12), and when the najar roller comes to the home position, the feed motor is stopped (S13), and a document jam is displayed (S14). After that, open the paper feed unit cover to recover the document jam. When the paper feed unit cover is closed again, the home position adjustment of the nudger roller has already been completed, so it is judged that the document jam is cleared (S1).
5). If the document is not jammed, the process returns to step S4.

In this embodiment, the home position adjusting operation of the nudger roller at the time of document jamming in the paper feeding section is described, but the same applies to document jamming at the document register section and the document discharging section. Further, in this embodiment, when the document jam occurs, the home position adjustment of the najar roller is performed only by the reverse rotation drive of the najar roller. Absent. In short, the home position of the najar roller is adjusted before the opening / closing operation of the paper feed unit cover so that the finger of the hand is not caught between the najar roller and the chute when the paper feed unit cover is operated. ..

Further, in this embodiment, only the nudger roller is reversely driven by using the one-way clutch, but a clutch for cutting off the power to the feed roller when a document jam occurs is provided and only the nudger roller is normally driven to rotate. You may make it align. Further, in the present embodiment, after the document jam is detected, the home position adjustment process of the najar roller (S11 to 13) is first performed, and then the document jam display process (S14) is performed.
This process may be reversed. That is, after the document jam is detected, the document jam display process is first performed, and then the home alignment process is performed.

According to this embodiment, the home position of the nudger roller is adjusted at various timings, so that the original document to be set can be prevented from being damaged and the reliability can be improved. If the home position of the nudger roller is configured to be controlled by the reverse rotation, the retard roller will not be worn. Further, when the home position of the nudger roller is configured to be controlled by the forward rotation when the belt motor is turned on, the belt motor can be assisted and the document can be pulled in smoothly.

[0033]

As described above, according to the present invention, the home position of the nudger roller is adjusted by the document jam detection signal, so that the fingers of the hand are placed between the nudger roller and the chute when the paper feed unit cover is closed. It is not pinched, and the safety of the automatic document feeder is improved. Further, the home alignment processing of the najar roller can be performed by software processing, which is more cost effective than mechanical processing. Furthermore, when the document jams, the home position of the nudger roller is configured to be driven in reverse rotation, so even if the document is caught in the nip between the retard roller and the feed roller, the document will be returned from the nip, improving operability. To be done.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of an automatic document feeder according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a document carry-in section of the automatic document feeder.

FIG. 3 is a plan view showing a configuration of a feed mechanism.

FIG. 4 is a control block diagram of a feed mechanism.

FIG. 5 is a flowchart of home position alignment control of a nudger roller in the automatic document feeder of the present invention.

FIG. 6 is a schematic configuration diagram of a copying machine equipped with an automatic document feeder.

[Explanation of symbols]

1 base machine, 2 automatic document feeder (ADF),
10 platen glass, 20 sheet mounting table, 30 sheet feeding section, 30a sheet feeding section cover, 38 nager roller,
39A feed roller, 39B retard roller, 4
0 document registration unit, 44 feed motor, 47 rotation detection plate, 48 detection unit, 100 feed motor controller, 101 motor drive circuit, 50 document ejection unit, 51 document ejection tray, S1 to S6 sensors

Claims (4)

[Claims] 1. A feed mechanism for feeding a document from a sheet stacking portion, a najar roller having a curved discontinuous portion incorporated in the feed mechanism, a home position sensor for detecting the position of the najar roller, and the home. In an automatic document feeder including a driving unit that drives the najar roller to a home position by a signal from a position sensor, a unit that detects a document jam in the sheet conveyance path and a document jam detection signal that moves the najar roller to the home position. An automatic document feeder including a controller for outputting a rotation drive command for adjusting the above to the nudger roller drive means. 2. The feed mechanism comprises a feed roller, a nudger roller, and one drive means for driving the roller, and the feed roller is driven via a one-way clutch for rotating only in the sheet feeding direction. The automatic document feeder according to claim 1, wherein: 3. The automatic document feeder according to claim 2, wherein the home position of the nudger roller is adjusted by reverse rotation drive when a document jam occurs. 4. The automatic document feeding according to claim 1, further comprising a clutch for separating the feed roller from the driving means, and when the document is jammed, the clutch is operated so that the home position of the nudger roller is driven by forward rotation drive. apparatus.