JPH066457B2 - Automatic document feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder that supplies and conveys a document onto a platen of an image processing apparatus such as a copying machine or an image reader.

[Conventional technology]

An image forming apparatus, such as an automatic document feeder attached to a copying machine, feeds the documents set on a document tray one by one by a separating / feeding device, conveys them on a platen with a conveyor belt, and stops the documents at a reference position. Copying is performed, and after the copying is completed, the document is again transported from the platen by the transport belt and discharged to the discharge tray by the discharge rollers.

In such an automatic document feeder, the conveying belt is decelerated immediately before the stop in order to improve the accuracy of stopping the original at the reference position.

Also, when ejecting a copied document to the output tray,
The paper ejection roller is decelerated to improve the alignment.

[Problems to be solved by the invention]

However, if the above two deceleration operations are simply performed, the drive of the deceleration belt and the discharge roller must be separated.

[Object of the Invention]

The present invention, while driving the conveying means such as a conveyor belt and the discharging means such as a paper discharge roller by the same driving device,
An object of the present invention is to obtain an automatic document feeder which has good stopping accuracy on the document setting surface and good alignment of discharged documents.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings.

<Structure> As shown in FIG. 2, an automatic document feeder 5 is mounted on an image processing apparatus, for example, a platen 3 (original setting surface) of the copying machine 1.

The automatic document feeder 5 includes a document tray 7, a separating / feeding unit 9 (feeding means) for separating and feeding the document set on the document tray 7 into one sheet, and the separating / feeding unit 9
The document sent from the platen 3, a transport unit 11 (transport unit), a discharge unit 13 (discharge unit) that reverses and discharges the copied document, and a document discharged from the discharge unit 13. A paper discharge tray 15 for accommodating paper and a control device (not shown) are provided to automatically feed and discharge a document. The transport unit 11 and the discharge unit 13 are integrated with the cover C, and are attached to the rear surface of the copying machine 1 via a hinge so that they can be opened and closed manually.

The separating / feeding unit 9 is configured as shown in FIG.

First, the paper feed path 19 is formed by the guides 23, 24, and 25, and the separation roller 31 and the paper feed roller 33 are arranged to face each other.

The separation roller 31 is attached to the rotary shaft 35 via a one-way clutch, and is rotationally driven by a motor 27 in a direction opposite to the paper feeding direction (clockwise in the drawing). Paper feed roller 3
3 is also attached to the rotary shaft 37 via a one-way clutch, and is rotationally driven by the motor 27 in the paper feeding direction (clockwise in the drawing).

The separation roller 31 is pressed against the paper feed roller 33 by the solenoid 32 or separated from the paper feed roller 33.

The shaft 37 of the paper feed roller 33 has a connecting portion 39 and a locking portion 4 on the shaft 37.
An arm 43 provided with 1 is rotatably attached. A pickup roller 47 is attached to the connecting portion 39 via a rotary shaft 45, and the timing pulleys 44, 46 are attached.
Also, it rotates together with the paper feed roller 33 via the timing belt 49.

A lever-type sensor 48 for detecting whether or not the document P is set on the document tray 7 is attached near the pickup roller 47.

Above the arm 43, a lever 55 attached to a shaft 53 driven by a latching (keeping) solenoid 52 is provided. The lever 55 supports the locking portion 41 and locks the rotation of the arm 43.

Also, the shaft 5 driven by the latching solenoid 52
7 is provided with a set stopper 59, which prevents the document P from entering the paper feed path 19 when the document P is descending.

For the latching solenoid 52, for example, a permanent magnet is also used in the magnetic circuit of a DC solenoid, and when an instantaneous current is applied to the solenoid, the iron core in the solenoid is attracted and the state is retained by the permanent magnet. When an instantaneous current having a polarity opposite to that of time is applied, the holding force of the permanent magnet is weakened, and the iron core is restored by the return spring.

Registration rollers 51 and 54 are provided in front of the separation roller 31 and the paper feed roller 33. The registration roller 51 is driven by the motor 56.

A clock plate 61 having a plurality of holes provided at equal intervals on the same circumference is attached to the rotation shaft of the motor 56, and the holes of the clock plate 61 are opened by an optical sensor 62 having a light emitting element and a light receiving element. By detecting as a pulse, the rotation amount of the motor 56 is detected.

A lever-type contact sensor 63 is provided at the entrance of the registration rollers 51 and 54, and an optical non-contact sensor 64 is provided on the contact portion between the registration roller 51 and the registration roller 54. There is.

As shown in FIG. 2, the transport unit 11 has a transport belt 81 whose both ends are supported by rollers 83 and 85, and the middle of which is pressed against the platen 3 by rollers 87. The roller 85 is the motor 9
1 (driving device).

A clock plate 93 is attached to the rotation shaft of the motor 91, and the amount of rotation is detected by the sensor 65.

As shown in FIG. 2, the discharge unit 13 is provided with a reversal path 101, discharge rollers 107, 109, 111, 113, a discharge sensor 110, and a discharge port 114. The paper discharge rollers 107 and 111 are driven by the motor 91.

The paper discharge tray 15 is configured as shown in FIGS.

The paper discharge tray 15 is formed integrally with the cover C and has a recess 1
41 is provided. Above the paper discharge tray 15, a hollow slide rail 14 is arranged in the discharge direction from above the paper discharge port 114.
3 is provided horizontally.

A groove 145 is provided in a portion of the sliding rail 143 corresponding to the recess 141. In the sliding rail 143, a plurality of photo interrupters 147 provided with position detecting means, for example, a light emitting element and a light receiving element, are provided facing the groove 145. These photo interrupters 147 are
They are attached at positions separated from the sheet discharge port 114 by a distance obtained by adding a predetermined length to the lengths of various documents. The position detecting means may be a reed switch or the like.

The sliding rail 143 has arms 149L and 149 on the left and right.
A document stopper 149 having an R is slidably fitted therein. Inside the document stopper 149, a light-shielding plate 151 that enters the groove 145 is provided as shown in FIG. 5, and the document stopper 14 is provided along the slide rail 143.
By moving 9, the photo interrupter 147 is turned on / off by the light shielding plate 151.

The document stopper 149 is configured to move on the slide rail 143 by the moving device 153 shown in FIG. This moving device 153 has wires 1 attached to both ends of the light shielding plate 151 through the inside of the slide rail 143.
55 and the pulley 15 supporting both ends of this wire 155.
7, 159, a pulley 161 coaxially attached to the pulley 159, a motor 163, a pulley 165 attached to a rotation shaft of the motor 163, and the pulley 1
65 and a wire 167 that connects the pulley 161.

The photo interrupter 147 and the motor 163 are connected to a determination unit such as a microcomputer that determines the position compatibility of the document stopper 149, and the size of the document detected by the size detection unit provided in the separation feeding unit 9 and the light shielding plate 151. It is determined whether the document size of the photo interrupter 147 that has detected is coincident, and if they are not coincident, the motor 163 is driven, and the photo interrupter 147 corresponding to the document size detects the light shielding plate 151. The document stopper 149 is moved up to.

The control device includes, for example, a microcomputer, and based on signals from the sensors 48, 62, 63, 64, 65, 110 and the photo interrupter 147, the solenoids 32, 52.
The motors 27, 56, 91, 163 and the like are driven and controlled.

Particularly, this control device operates the motor 91 to discharge the original document, which has been copied, to the discharge tray 15 by the motor 56.
Is operated to set the original at the reference position by supplying the next original to the conveyor belt 81, and the motor 91 is decelerated while performing these operations. It is supposed to do.

In FIG. 7, L1 is the distance from the reference position to the trailing edge of the document A at the time of deceleration ejection. Distance L2: Sum of X1 and X2 V1: Document transport speed of the transport belt 81 V2: Circumferential velocity of the registration rollers 51, 54 T7: Time difference between when the motor 91 starts driving and when the motor 56 starts driving (document Replacement timing time), the time T5 from the drive start of the motor 91 to the deceleration discharge timing is T5 = L1 / V1. The time T6 from the start of driving the motor 91 to the deceleration stop timing is T6 = (X1 / V2) + (X2 / V1) + T7. Therefore, the original replacement timing time T7 is variable depending on the size of the original so that T5 = T6.

<Operation> The operation of this device having such a configuration will be described with reference to the timing chart of FIG.

First, when the document P is set on the document tray 7 with the surface thereof facing downward, the sensor 48 detects the document and the document can be automatically fed.

When a paper feed button (not shown) of the automatic document feeder 5 is pressed in such a state, the latching solenoid 52 and the solenoid 32 shown in FIG. 3 are excited. Excitation of the solenoid 52 causes the lever 55 to rotate counterclockwise in the figure.
Therefore, the pickup roller 47 falls on the document.

Further, the excitation of the solenoid 52 causes the shaft 57 to rotate clockwise, and the set stopper 59 to rotate upward. Therefore,
Paper can be fed. Further, the separation roller 31 is pressed against the paper feed roller 33 by the excitation of the solenoid 32.

When the pickup roller 47 contacts the document P on the document tray 7, the motor 27 is rotated. As a result, the paper feed roller 33 and the pickup roller 47 rotate in the paper feed direction, and the separation roller 31 rotates in the opposite direction to the paper feed direction.

The original on the original tray 7 is sent out by the rotation of the pickup roller 47, and the original following the original is rejected by the separating roller 31 and fed by the paper feed roller 33. Then, the sensor 63 detects the leading edge of the document, and the leading edge of the document is abutted against the contact portion between the registration roller 51 and the registration roller 54. Since the document is further fed by the paper feed roller 33 with the leading edge of the original locked, the original bends and the leading edge of the original is registered.

The energization of the solenoid 32 and the motor 27 is stopped T1 time after the sensor 63 detects the leading edge of the document.

Therefore, the motor 27 is stopped, the feeding of the original is stopped, and the separation roller 31 is separated from the feeding roller 33. At that time, since the pickup roller 47 is in contact with the document, the deflection of the document is maintained.

The motors 56, 9 after T2 time from when the sensor 63 is turned on
1 is rotated, and the solenoid 52 is reversely excited.
As a result, the registration roller 51 and the conveyor belt 81 rotate and the pickup roller 47 moves up.

The rotation of the motors 56 and 91 causes the sensors 62 and 65 to detect the pulses of the clock plates 61 and 93. Further, the original document registered by the rotation of the registration roller 51 is sent out and detected by the sensor 64. When the trailing edge of the document passes the sensor 64, the sensor 64 turns off and the motor 56 stops. Further, the motor 91 is decelerated.

By the way, after the contact type sensor 63 detects a document, which has a slow response speed but does not interfere with the document detection even if the document has a black portion, the response speed is fast but the document detection is made when there is a black portion on the detection line of the document. When the non-contact sensor 64 detects a document, the registration roller 51 (motor 5
The size obtained as the starting point of the rotation amount detection of 6) and the end point of the rotation amount detection of the registration roller 51 (motor 56) when the sensor 64 stops detecting the original document after the sensor 63 stops detecting the original document. The corresponding document size is detected by the number of pulses of the clock signal.

For this reason, even if one of the sensors 63 and 64 is temporarily turned off between the start point and the end point, the other sensor detects the original document, and the size is reliably detected.

The non-contact type sensor 64 compensates for the slow response speed, which is a drawback of the contact type sensor 63.
The contact type sensor 63 compensates for the detection error of the black portion, which is the drawback of the above.

The original size thus detected is compared with the original size of the photo interrupter 147 detecting the light shielding plate 151. If they do not match, the motor 163 is driven to correspond to the original size. The document stopper 149 is moved until the photo interrupter 147 detects the light blocking plate 151.

The document sent out from the separating / feeding unit 9 is conveyed on the platen 3. Then, the motor 91 is stopped T3 hours after the sensor 64 is turned off, and the document is set at the copy position (reference position).

By the way, the solenoids 32 and 52 are excited after a lapse of T4 from the time when the motor 91 is stopped, and the next original is advanced to the position of the registration roller 51.

The original set at the copy position is copied by the copying machine 1, and when the copying is completed, the motor 91 rotates and the original is supplied to the reverse path 101.

It should be noted that the motor 5 is rotated 7 hours after the motor 91 rotates.
6. The solenoid 52 is energized, and the original document is sent out onto the platen 3. That is, the first-out document is sent to the platen 3 after the discharge operation of the document on the platen 3 is started.

Then, the motor 91 is decelerated T 5 hours after the motor 91 starts driving, and the document is discharged from the paper discharge port 114 to the paper discharge tray 15. The front end of this original is received by the original stopper 149, and the paper exit 114 and the original stopper 1
It is housed between 49 and. Therefore, the originals are aligned.

Further, by decelerating the motor 91, the original document is set at the copy position on the platen 3 at a low speed.

In this way, a plurality of originals are sequentially sent out, copied and discharged.

<Effects of Embodiment> According to the embodiment described above, the following effects can be obtained.

(1) When the motor 91 is operated to discharge the copied document to the discharge tray 15, the motor 56 is operated to set the document at the reference position where the next document is supplied to the conveyor belt 81. Since the motor 91 is decelerated while performing these operations,
The operation of ejecting the original after the copying and the operation of stopping the next original are simultaneously performed at a low speed, and the conveyance belt 81 and the ejection roller 1
While the 07 and 111 are driven by the same motor 91, the stopping accuracy on the platen 3 is good and the alignment of the discharged originals is good.

(2) Original replacement timing time T for each original size
Since 7 is variable, it is possible to perform the continuous paper feeding operation while discharging the paper without ejecting the first-come-first-served document after discharging the copy-completed document, reducing the loss time and the shortest time. Manuscripts can be exchanged.

[Modification]

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, a screen of a double-sided original is set on the original setting surface one by one, and image processing of both sides of the original is performed. It can also be applied to an automatic document feeder having a front / back reversing function.

〔The invention's effect〕

In short, the present invention has been described above in which the feeding means for feeding the original from the original tray and the original fed by the feeding means are conveyed along the original setting surface of the image processing apparatus,
An automatic document feeder including: a conveying unit that sets a document at a reference position on a document setting surface; and a discharging unit that discharges the document to a discharge tray after the image processing is performed by the image processing apparatus. The apparatus further comprises a driving device for driving the discharging means at the same time, and when discharging the document on which the image processing is completed to the discharge tray, the sending means is operated to supply the next document to the conveying means. When the operation of setting the document at the reference position is performed and the trailing edge of the document after the image processing reaches the “predetermined position on the upstream side of the discharging unit”, the driving device is decelerated and At the time of deceleration start, "the distance from the predetermined position to the ejecting means"<the distance from the rear end of the next document to the reference position,
Since the control means for controlling the operation start timing of the feeding means is provided according to the size of the document for which the image processing is completed, the operation for discharging the document for which the image processing is completed and the operation for stopping the next document are simultaneously performed at low speed. Therefore, there is no dead time for exchanging the originals, and the stopping accuracy at the stop reference position is good and the alignment of the discharged originals is improved at the same time while the conveying means and the discharging means are driven by the same driving device. it can.

Further, there is no possibility that the original cannot be completely ejected during ejection and remains in the ejection means.

[Brief description of drawings]

1 to 8 are views showing an embodiment of the present invention. FIG. 1 is a plan view showing the structure of an automatic document feeder, FIG. 2 is a sectional view showing the structure of the automatic document feeder, FIG. 3 is a view showing the structure of the separating / feeding section, FIG. 4 is a perspective view of the discharge tray, FIG. 5 is a sectional view of the document stopper, and FIG. 6 is a switching gate driving device and a document stopper moving device. FIG. 7 is a diagram showing the structure of FIG. 7, FIG. 7 is a timing explanatory diagram of document feeding and discharging,
FIG. 8 is a timing chart for explaining the operation. DESCRIPTION OF SYMBOLS 1 ... Copier 3 ... Platen 5 ... Automatic document feeder 7 ... Document tray 9 ... Separation feeding unit 11 ... Conveying unit 13 ... Ejecting unit 15 ... Ejection tray 31 ... Separation roller 33 ... Paper feeding roller 47 ... Pickup roller 51 , 54 ... Registration rollers 56 ... Motor 81 ... Conveying belt 91 ... Motor 107,
111 ... Paper ejection roller

Claims (1)

[Claims] 1. A feeding means for feeding a document from a document tray, and a feeding means for feeding the document fed by the feeding means along a document setting surface of an image processing apparatus and setting it at a reference position on the document setting surface. In an automatic document feeder including a discharge unit that discharges the document to a discharge tray after performing image processing by the image processing apparatus, the automatic document feeder includes a drive unit that drives the transport unit and the discharge unit at the same time. At the same time, when the document on which the image processing has been completed is discharged to the discharge tray, the feeding means is operated to supply the next document to the conveying means to set the document at the reference position. When the trailing edge of the document on which the image processing is completed reaches a predetermined position on the upstream side of the discharging means, the driving device is decelerated, and at the start of deceleration of the driving means, The operation start timing of the feeding unit is controlled according to the size of the document on which the image processing is completed so that the distance from the predetermined position to the discharging unit <the distance from the rear end of the next document to the reference position. An automatic document feeder having a control means.