JP2001031284A - Automatic document carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase efficiency of carrying operation by staying the next document in standby by separating/feeding the next document in reading a preceding document, and carrying the next document at a speed higher than a reading time carrying speed up to an upstream prescribed position from a reading position in reaching a prescribed interval after the next document and the reading preceding document separate from each other. SOLUTION: An (n)th document waiting for inputting a start signal from a body control part in a register position after already completing first-out, is started to be carried downstream by a reading motor driven by the start signal, and is carried so as to become a specific reading speed before the document tip reaches up to at least a reading position. This control is performed by means of the pulse count of the reading motor. Reading of the (n)th document is started, and when detecting the rear end by a butting sensor 29, first-out operation of an (n+1)th document is started to simultaneously start an inter- paper pulse count (a pulse count of the reading motor) for deciding the timing for driving a register roller 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus or an image forming apparatus which separates and feeds a document to be read, conveys the document to a reading position, and reads the image by a fixed reading section while conveying the document. To an automatic document feeder.

[0002]

2. Description of the Related Art In a conventional copying machine, when a copy is made from a plurality of originals, one copy is sequentially placed on a set of originals placed face up on a document set table.
2. Description of the Related Art An automatic document feeder that extracts a document one by one, feeds the document onto a contact glass of a copying machine body, and discharges a document after exposure of the document to a discharge unit is used.

In such an automatic document feeder, after the trailing edge of the document conveyed to the reading position passes through the reading position (after the reading is completed), the next document is conveyed to the reading position as quickly as possible under the reading control. In addition, there is a problem of increasing the read production efficiency.

For example, in the apparatus described in Japanese Patent Application Laid-Open No. 9-46472, the separation and feeding speed is made faster than the speed of the reading and conveying means, and is set to the same speed before the leading edge of the original enters the reading and conveying means. The reading section fills the gap between the originals opened by the paper section to improve production efficiency.

In the apparatus described in Japanese Patent Application Laid-Open No. 8-201830, the transport speed is controlled such that the interval between the front and rear documents is kept constant by a plurality of sensors and driving means, thereby reducing the size of the apparatus. Is being planned.

[0006]

However, in the technique disclosed in Japanese Patent Application Laid-Open No. Hei 9-46472, the slip of the separation sheet feeding section (the separation sheet feeding section has the problem of deterioration of the friction coefficient of the separation sheet feeding member and various other problems). It is very difficult to maintain a constant transport speed because of the different coefficients of friction for each document over a wide range of documents.) (Some originals stop at the original setting position and some enter the separation paper feed unit due to frictional force between the originals.) Because the transport time to the reading position varies, variations between the original sheets in the reading unit occur. It is not possible to control the gap between the original sheets constantly. For this reason, the production efficiency is reduced by the variation between the manuscript sheets. In addition, the separation sheet feeding speed is specific to each separation method, and there is a limit in controlling the separation sheet feeding conveyance speed.

In the technique disclosed in Japanese Patent Application Laid-Open No. 8-201830, control is performed so as to maintain a constant document interval during conveyance, and there is a problem that the control is complicated.

It is an object of the present invention to provide an automatic document feeder which can solve the above-mentioned problems and can maintain a constant document interval so that production efficiency is maximized regardless of the separation method. It is in.

[0009]

According to the present invention, an intermediary conveyance means between a separation paper feeding means and a reading conveyance means is used to set a space between originals at the time of reading and conveying (a first original and a next original on a conveying path). (Interval) is kept as small and constant as possible in reading control, the conveying speed by the intermediate conveying means is set to be higher than that during reading and conveying, and the time between reading and conveying before the leading edge of the original enters the reading and conveying means. The problem is solved by maintaining the same speed and shortening the interval between the original sheets opened during the separation and feeding. Note that the leading operation of the next original and the start of the intermediate conveying operation by the separation sheet feeding unit are performed at the timing when the rear end of the original being read is conveyed to a predetermined position.

According to the first aspect of the present invention, there is provided a separation sheet feeding means for separating and feeding a document one by one from a document stack including a plurality of stacked documents, and transporting the fed document to a reading position. A reading / conveying unit; a driving unit for driving the separation / feeding unit and the reading / conveying unit; and a driving control unit for controlling the driving unit. When the next document and the previous document being read are separated and reach a predetermined interval, the next document is transported to a predetermined position upstream of the reading position at a speed higher than the transport speed at the time of reading, The feature is that the interval between the front and rear documents is reduced.

According to a second aspect of the present invention, there is provided a separating sheet feeding means for separating and feeding a document one by one from a document bundle comprising a plurality of stacked documents, and a predetermined sheet upstream of a reading position of the conveyed document. A reading / conveying means for conveying a document from a position to a reading position at a predetermined speed, an intermediate conveying means for conveying a separately fed document to the reading / conveying means,
A driving unit for driving the intermediate conveying unit; and a driving control unit for controlling the driving unit. The reading unit separates and feeds the next original while reading the previous original, and waits for the next original to be read. By transporting the next document to the reading and transporting device at a speed higher than the predetermined speed based on the interval with the previous document,
It is characterized in that the document interval once extended in the previous document reading operation is shortened during intermediate conveyance.

According to a third aspect of the present invention, the image forming apparatus further comprises a leading edge detecting means for detecting a leading edge of the next document upstream of the intermediate conveying means, based on information detected by the leading edge detecting means. It is characterized in that the intermediate conveying means is driven so that the next original is conveyed at a speed equal to the conveying speed by the reading and conveying means before the leading edge of the original reaches the reading and conveying means.

According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the third aspect, further comprising a trailing edge detecting means for detecting a trailing edge of the preceding document downstream of the separating sheet feeding means.
It is characterized in that the next document that has been separated and fed and is on standby is transported to the reading transport unit.

According to a fifth aspect of the present invention, during the reading of the previous original, the feeding of the next original by the separation feeding unit is completed before the start of the conveyance of the next original by the intermediate conveying unit. It has special features.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire configuration of an automatic document feeder mounted on a copying machine according to an embodiment of the present invention, and FIGS. 2 and 3 show the configuration of a control unit thereof.

The automatic document feeder (hereinafter referred to as A
DF) 200 is provided in a copying machine (not shown). In this copying machine, the fixed reading unit
While the document is being conveyed at a predetermined speed from F200, the reading unit reads the image.

The ADF 200 includes a bundle of originals S to be read.
, A separation feeding unit 2 for separating and feeding originals one by one from the set of originals S, firstly abutting and aligning the fed originals, and A registration unit 3 that pulls out and conveys the document, a reversing unit 4 that turns the document conveyed to the reading position, and conveys the image surface toward a reading unit (not shown) on the lower side of the main body, and a surface of the document being read and conveyed A first reading / conveying unit 5 for reading an image from below the contact glass 54, a second reading / conveying unit 6 for reading the back side image while conveying the front side original, and reading the original whose front and back surfaces have been read out of the machine or A paper discharge unit 7 for feeding the reversing conveyance unit 8, a reversing conveyance unit 8 for performing a switchback operation for re-reading, a stacking unit 9 for stacking and holding originals after reading, and a driving unit 101 for driving these conveyance operations. ~ 1 05 (shown in FIG. 2), a controller 100 (shown in FIG. 2) for controlling a series of operations,
And so on.

The document setting section 1 includes a document setting table 1
0, side guide 11, first document length sensor 12, second document
A document length sensor 14, a document stopper 25, and the like are provided to set a document bundle S of one-sided or two-sided documents. The document set table 10 is configured to be rotatable and retractable upward around a rotation fulcrum (not shown), thereby facilitating removal of stacked documents.

The separation paper feed unit 2 includes a pickup roller 2
0, a paper feed belt 23, a separation roller 26, etc., and a document bundle S set on the document set table 10.
The original is separated and fed for each sheet.

The registration section 3 is composed of a butting sensor 29, a registration roller 30, a size sensor group 32, and the like. The registration section 3 performs an operation of firstly abutting and aligning a fed document, and pulling out the aligned document. Performs the action of transport.

The reversing unit 4 is composed of a reading and conveying roller 43, a pressure roller 35, a registration sensor 40, and the like. The reversing unit 4 reverses the conveyed document and conveys the document surface toward the reading side (downward).

The first reading and conveying section 5 includes a reading and conveying roller 4
3. A pressure roller 41, a white background plate 51, a contact glass 54, and the like, and a surface image of the document is read from below the contact glass 54.

The second reading / conveying section 6 is composed of a contact image sensor 61, a pressing member 62, and the like, and reads the back side image of the original after the front side reading.

The paper discharge section 7 is composed of a paper discharge drive roller 71, a paper discharge pressure roller 72, a paper discharge sensor 70, and the like, and conveys the original whose front and back sides have been read to the outside or the reverse conveyance section 8. .

The reversing transport section 8 is composed of a reversing switching claw 80, a pair of reversing discharge rollers 81, 82, and the like, and performs reversal for re-reading after reading the front side. Note that the switchback path 83 forms an intermediate stack.

The stack section 9 is composed of a paper discharge stacker 90 and the like, and stacks and holds originals after reading is completed.

These transport operations are performed by driving the driving units including the motors 101 to 104 and the reversing switching solenoid 105 in FIG.

Here, the configuration of the control unit of the copier equipped with the ADF 200 of the embodiment will be described.

As shown in FIG. 2, the ADF 200 mounted on the main body of the apparatus has a controller 100 for controlling the operation of the ADF 200. The controller 100 controls the sensors 12, 14, 15, 19, 28, and 29. , 32, 3
Detection signals from 4, 40, 70, 84, etc., motors (for example, constituted by stepping motors) 101 to 104, inversion switching solenoids 105, status signals from the completed stamp 73, and an interface unit with the main body control unit 111 ( A control signal (a start signal or the like) transmitted via a serial communication line) 107 or a table open signal indicating that the document set table 10 is open is input.

The controller 100 transmits the information indicated by the signals from the sensors to the main body control unit 111, and based on the control signals transmitted from the main body control unit 111, controls the motors 101 to 104, The drive of the solenoid 105, the completed stamp 73, and the like is controlled. At this time, the document set sensor 28 is
When a document S is set on the interface unit 1, the detection information is sent to the interface unit 1 by the controller 100.
The original setting signal is transmitted to the main body control unit 111 as a document set signal via the control unit 07. Alternatively, the table opening / closing sensor 15
When detecting that the document set table 10 of F200 is in the lifted state, the detection information is transmitted to the main body control unit 111 as a liftup signal via the interface unit 107 by the controller 100.

The controller 100 supplies power to the contact image sensor 61 disposed on the ADF side as shown in FIG. Further, the controller 100
Sends a timing signal indicating a reading timing to the contact image sensor 61 based on a control signal transmitted from the main body control unit 111, and turns on / off a light source for exposure.

The contact image sensor 61 includes a light source unit (LED) 208 for exposure when reading a document, and a CCD sensor chip 201 for reading an image surface of the document and photoelectrically converting the information into an electric signal (analog signal). , An amplifier 202 for amplifying the analog signal, and an A / D converter 2 for converting the amplified analog signal into a digital signal
03, an image processing unit 204 for generating image information from the digital signal, a frame memory 205 for expanding and storing the image information, and a main unit control unit via the interface circuit 207 for transferring the image information stored in the frame memory 205. 1
11 and an output control circuit 206 for sending out to the ADF
The exposure processing is performed in accordance with a timing signal from the side, and the acquired image information is transmitted to the main body side.

The controller 100 has a RAM (not shown).
The operation mode input and set from is stored, and the stored contents are updated each time the operation mode is changed. For example, originals of different sizes are mixed on the original set table 10,
There are a mixed mode for reading originals at a predetermined conveyance speed according to the size, a unified size mode for reading originals of different sizes and outputting them on recording paper of the same size, a double-sided / single-sided mode for reading double-sided or single-sided originals, and the like. . Also,
In this RAM, the document size determined in combination with the document size in the transport direction calculated based on the detection information of the document length sensors 12 and 14 and the document size in the width direction detected by the size sensor group 32 , Etc. are stored.

On the other hand, the main body control section 111 controls the entire apparatus, and outputs detection information signals from various sensors (not shown) on the main body side and input / output sections (various loads such as drive motors and clutches not shown). ADF2 via the interface unit 107, status signals and various signals from the operation unit 108
00, an information signal such as a document jam or a serviceman call, image information from the contact image sensor 61, and the like.

The main body control unit 111 performs drive control of the input / output unit, display control in the operation unit 108, and the like based on the information indicated by the signal thus received and input. , Or a start signal for starting the sheet feeding operation by driving the pickup roller 20 to rotate, and a start signal for starting a reading operation by the contact image sensor 61 in accordance with the transport timing of the ADF 200. Sends a signal and instructs the controller 100 to
The control unit 200 controls a sheet feeding / conveying operation or a reading speed (conveying speed).

The operation unit 108 has various button keys such as a start button and a numeric keypad (not shown), an LCD display, and the like, and operates in each of the operation modes such as the mixed mode, the single-sided / double-sided mode, and the like. The configuration and the operation start / stop instruction can be performed by a user operation. Further, when the start button is pressed after the document set is detected, the main body control unit 111 stores the press information in a predetermined memory area in the main body control unit 111 and transmits a start signal to the ADF 200 based on the press information. By transmitting the start signal in this manner, the ADF 200
Then, the pickup roller 20 is automatically driven and rotated to start the paper feeding operation, and the first transport reading unit 5 on the main body side and the ADF
The reading operation is performed by the second transport reading unit 6 on the side.

Next, a description will be given of a transport operation of the original bundle S of the same size according to the present embodiment.

First, the original bundle S to be read is set on the original set table 10 with its leading end abutting on the broken line position of the original stopper 25, and the width direction of the original bundle S is set in a side guide (shown in detail). (Not provided but arranged before and after) 11 for positioning in the direction orthogonal to the transport direction.

In this state, the original set detection filler 21
Is displaced from the position indicated by the broken line to the position indicated by the solid line. With this, the light shielding of the document set sensor 28 is released.
An original set signal is transmitted to 11. Further, a first original length sensor 12 or a second original length sensor 14 provided on the original set table surface (both are constituted by a reflection type sensor or an actuator type sensor capable of detecting even one original, At least the document is arranged so as to be able to determine whether it is vertical or horizontal with the same document size.), The approximate length of the document in the transport direction is determined.

Thereafter, a document feed signal (input from the operation unit 108 and sent from the main unit control unit 111 to the interface unit 10)
7 through 7), the document feeding operation shown in FIGS. 4 to 6 is executed.

As shown in FIGS. 4 to 6, when the setting of the original is detected (step S1), the original stopper 25 is retracted to the solid line position by the CW (forward rotation) driving of the calling motor 101 (step S2). (YES in step S3),
Open the leading edge of the document. In this embodiment, a stepping motor (calling motor) is used as the driving device, but this can be replaced with a suction / opening operation of the solenoid.

Thereafter, the pickup roller 20 is moved from the broken line position to the upper surface of the original document indicated by the solid line position by the reverse rotation of the calling motor 101 (step S4), and is pressed with a predetermined force (YES in step S5, step S4).
6). The home position sensor 19 is an optical reflection type sensor for detecting the state of the pickup roller 20 and the document stopper 25.

When the number of documents is small during the pressure contact operation of the pickup roller, the drop height is large, and the cushioning effect of the document between the document set table 10 and the pickup roller 20 is small. The problem that the sound becomes loud occurs. Therefore, in the present embodiment, a concave roller escape groove is formed at the point of contact with the pickup roller 20 of the document set table 10, and the pickup roller 20 is directly
The document set table 10 is configured not to hit.

Thereafter, after a lapse of a predetermined time, the separation / feed unit 2
And the sheet supply motor 102 for driving the registration unit 3
The pickup roller 20 is rotated in the clockwise direction (step S7), and the uppermost sheet of the document bundle S is fed in the direction of the separation sheet feeding unit 2.

At this time, the paper feed belt 23 is stretched around the belt pulleys 22 and 24 with a predetermined tension, and is pressed against the separation roller 26 disposed opposite to the belt. The separation roller 26 is driven by a torque limiter (not shown) having a predetermined torque.
When driven by friction and directly engaged with the paper feed belt 23, or in a state where the original is engaged via one sheet, the document is rotated counterclockwise with the rotation of the paper feed belt 23, and If two or more sheets enter between the paper feed belt 23 and the separation roller 26, the co-rotating force is set to be smaller than the torque of the torque limiter, and the separation roller 26 is moved in the original driving direction. It rotates in a clockwise direction and pushes back the excess document to prevent double feeding.

The document separated into one sheet by the action of the paper feed belt 23 and the separation roller 26 is further conveyed by the paper feed belt 23 and travels along the paper feed path 27 in this process.
The tip is detected by the butting sensor 29 (step
(YES in S8), and goes further and hits the stopped registration roller 30 (step S9). At this time, by rotating the calling motor 101 in the CCW direction (step S12), the pickup roller 20 is retracted from the upper surface of the document (YES in step S13, step S14), and the document is fed only by the conveyance force of the paper feed belt 23. Thus, the leading edge of the document enters the nip portion between the pair of upper and lower rollers of the registration roller 30, and the leading edge is aligned (abutment skew correction).

In step S8, the contact sensor 29
If the predetermined time has elapsed without turning on (YES in step S10), it is determined that the jam has not been reached (step S11).

In step S14, the calling motor 10
After the stop of the roller 1, the roller is fed by a predetermined distance from the detection of the butting sensor 29 (YES in step S15). As a result, the feed is performed while the resist roller 30 is pressed against the resist roller 30 with a predetermined amount of bending. By driving the paper motor 102 in the reverse direction, the driving of the paper feed belt 23 is stopped (Step S).
16).

The resist roller 30 is driven by the reverse rotation of the paper feed motor 102, and conveys the document in the direction of the reversing section 4. Here, when the first sheet of the document bundle is fed to the registration stop position, the conveyance speed of the registration roller 30 is set higher than the reading speed, and the reading conveyance roller 43 is also driven by the reading motor 103 at the same speed. .

The width of the leading end of the document past the registration roller 30 is detected by the size sensor group 32 in the direction perpendicular to the conveying direction. When an accurate document size is determined by a combination of the width signal and the length signal obtained by the first document length detection sensor 12 or the second document length detection sensor 14, the main body control unit 111 is notified. Then, a document size signal is transmitted from the controller 100 via the interface unit 107 (steps S17 to S20).

Thereafter, when the registration sensor 40 detects the leading edge of the document that has passed the leading edge sensor 34 (step S2).
1 (YES in S24), counts the driving pulses of the feed motor 102 and the read motor 103, and when the number of pulses reaches a predetermined number, the feed motor 102 and the read motor 103 are counted.
Is stopped, and a registration stop signal is transmitted from the controller 100 to the main body control unit 111, and a reading start signal from the main body control unit 111 (transmitted when synchronization with the transfer paper or preparation for storage in the image memory is completed) (Steps S25 to S30).

When the second and subsequent originals are transported, the next original is advanced. Here, the next original advance operation (from the original set position to the registration stop) controlled by the paper feed motor 102 will be described with reference to FIGS.

Reading / conveying roller 43 during reading of a document image
Is driven by the reading motor 103 at a speed corresponding to the reading magnification instructed from the main body control unit 111,
The transport speed of the next original must be fed to the nip between the transport roller 43 and the pressure roller 35 at the same speed as the speed of the read transport roller 43.

When the trailing edge of the original being read passes through the abutting sensor 29 (YES in step S121, YES in step S122), a pulse count for controlling the sheet interval (the driving pulse of the paper feed motor 102 is counted). ) To monitor the progress of the trailing edge of the original being read, and start the advance conveyance of the next original (step S123).

First, the pickup roller 20 is pressed against the upper surface of the next original document by the normal rotation of the calling motor 101 (steps S124 and S125), and then the paper feed motor 102 is driven to rotate forward until it hits the stopped registration roller 30. Convey (YE in steps S126 and S127)
S). Here, the position of the trailing end of the document being read is calculated from the above-mentioned pulse interval count value, and the paper feed motor 102 is driven to rotate in the reverse direction when a predetermined interval has passed from the registration unit 3.

That is, when the next original is detected by the butting sensor 29 (YES in step S127), counting of the abutting amount (feeding motor driving amount) is started and the calling motor 101 is driven to rotate forward (step S1).
30, S131), the pickup roller 20 is raised and retracted to the home position, and the calling motor 101 is stopped (YES in step S132, S133). Thereafter, when the abutting amount reaches a predetermined value (step S1).
34, YES), the sheet feeding motor 102 is stopped to end the butting operation (step S135), and when the inter-sheet pulse count value reaches a predetermined value (step S136).
YES), the feed motor speed is set to the advance speed (registration roller transport speed shown in FIG. 7) (step S13).
7). Then, by driving the sheet feeding motor 102 in the reverse direction (step S138), the next document is conveyed to the leading edge sensor position at a higher speed than the reading speed.

In this way, the registration roller 30 is driven at a high speed as in the case of transporting the first document. The registration roller 30 is fed to the leading edge sensor 34 at this speed, and the reading speed is detected by the leading edge sensor 34 (the speed of the reading transport roller 43). (Step S139: YES, Step S142). By performing this operation between successive documents, it is possible to recover the time stopped by the document abutting operation and maintain a predetermined document interval.

Thereafter, the original is sent to the nip between the reading / conveying roller 43 and the pressure roller 35, and the registration sensor 40
Detects the leading edge of the original (YE in step S143).
S), count the driving pulses of the registration roller 30,
The sheet feeding motor 102 and the reading motor 103 are stopped at the position where the predetermined pulse has been conveyed, and a registration stop signal is transmitted from the controller 100 to the main body control unit 111, so that the main body control unit 1
Wait for the input of the read start signal from step 11 (step
S146 to S149). A document reading operation is performed by inputting the reading start signal.

If the abutment sensor 29 is off for a predetermined time in step S124, if the tip sensor 34 is off for a predetermined time in step S139, or if the registration sensor 40 is off for a predetermined time in step S143, It is determined that a jam has been detected.
8 (YES in step S128, step S128).
129, YES in step S140, step S141,
YES in step S144, step S145).

Next, an original reading operation controlled by the reading motor 103 will be described with reference to FIGS.

The document whose registration is stopped is sent to the first reading and conveying unit 5 by the reading and conveying roller 43 and the pressing roller 41 which are rotated by the normal rotation of the reading motor 103. The driving speed of the reading motor 103 at this time is determined based on information transmitted from the main body control unit 111 to the controller 100 based on the reading magnification input from the main body operation unit 111 (NO in step S31 to step S33).

The first reading / transporting section 5 includes a contact glass 5
4 and a white background plate 51 arranged at a predetermined interval on the upper surface of the contact glass. During this time, an image is read by a reading system (not shown), converted into an electric signal via the CCD of the reading system, and stored in a memory device (not shown). In the reading / transporting section 5, a means for reducing the transport gap as much as possible and reducing the degree of freedom of the original is taken. As a method,
A method of extending a flexible guide member from the inner surface of the reading entrance guide 42 toward the white background plate 51 to fill the gap is effective. Further, since the white background plate 51 has a gap of about 0.5 mm ± 0.2 mm on the contact glass 54 and is pressed with a predetermined elasticity, the error in the reading depth direction is suppressed.

The surface of the contact glass 54 is treated with a surfactant (silicone-based activator) so that ink and the like are hardly adhered and fixed. In the reading position, the document surface does not actively contact the contact glass 54 at the reading position, and the leading edge of the document can wipe the vicinity of the reading position of the contact glass 54 (an action of scraping off foreign matter on the glass surface at the leading end). Is configured.

The timing at which the leading edge of the document arrives at the reading / transporting section 5 is controlled by the pulse count of the reading motor 103. At this timing, a front DF gate signal indicating the effective reading area of the front image in the sub-scanning direction is transmitted. (YES in step S34, step S35). afterwards,
The document is conveyed while reading, and is sent to the intermediate conveyance pressurizing roller 53 via the pickup guide 52. Since the intermediate conveyance pressure roller 53 and the pressure roller 41 are driven in common by the reading conveyance roller 43, the feeding speed and the drawing speed are the same, and there is an effect of reducing the occurrence of a transfer shock.

The original sent from the first reading and conveying section 5 by the intermediate conveying pressing roller 53 is sent to the second reading and conveying section 6 for reading the back surface, and is arranged above the conveying path with the reading section facing downward. It passes between the contact image sensor 61 and a pressing member 62 which is opposed to the reading surface of the contact image sensor 61 below the conveyance path and is disposed at a predetermined pressure and a predetermined interval. In the case of the double-sided mode (YES in step S36), the timing at which the leading edge of the document reaches the reading position by the close contact image sensor 61 is controlled by the conveyance pulse count from the leading edge detection of the registration sensor. Is transmitted to the backside DF gate signal to the contact sensor unit (YE in step S37).
S, step S38). Based on this signal, the image of the surface corresponding to the back side of the document is read, converted into an electric signal in the same manner as the front side, temporarily stored in the frame memory 205 shown in FIG. The pressing member 62 serves as a reference for shading and acts as a white background plate. The pressing member 62 is formed of a plate-shaped guide member in FIG. 1, but may be formed of a rotating body.

The timing of terminating the original reading areas on the front and back sides is controlled by pulse counting from the time when the leading edge of the original is detected by the paper discharge sensor 70 (YES in step S39) and the trailing end of the original is detected by the registration sensor 40. (YES in step S42 to step S50).

Thereafter, the original is discharged to the stack unit 9 by the discharge drive roller 71 and the discharge pressure roller 72. Note that the discharge stacker 90 is configured to be higher on the downstream side, which contributes to prevention of discharge document jumping out and improvement of stack document alignment accuracy.

During continuous reading of a plurality of originals, the driving of the reading motor 103 is stopped by the registration stop operation by the next original advance operation before the original discharge completion timing. When the trailing end of the document passes through the paper ejection sensor 70 by restarting the driving of the reading motor 103, the main body control unit 111
To complete the process (steps S51 and S52).

When stacking small-size originals, the reversing switching claw 80 of the reversing conveyance section 8 is set to the reversing switching solenoid 10.
5, the document is conveyed to the switchback path 83, and the reverse discharge roller pair 81, 82
Is discharged onto a small-size dedicated stacker 91 configured as a part of the original stacker 90. As a result, the visibility of the small-sized document after being discharged is improved.

The document set table 10 is configured so as to be able to retreat upward around a rotation fulcrum (not shown), thereby improving the stack document removal property.

When the original is ejected, the operation of the inversion switching claw 80 is synchronized with the trailing end of the ejected original. Immediately after the original is ejected, the inversion switching claw 80 is rotated in the direction of the broken line by the inversion switching solenoid 105. Control is performed to hit the rear end of the discharged document and prevent the trailing end of the discharged document from remaining. The above is an outline of the sheet feeding / conveying operation for a single-sided or double-sided original in the same-size original bundle.

Next, a description will be given of the operation of feeding and conveying one-sided / two-sided originals in the mixed mode (shown in FIGS. 11 to 16). This is an operation corresponding to the case of YES in step S31 of FIG.

In the mixed mode, since different document lengths are mixed, it is impossible for the document length sensors 12 and 14 on the document set table 10 to discriminate. For this reason,
When the originals are separated one by one, the size can be determined only when the rear end of the original separates from the original bundle S and becomes completely independent. Therefore, when it is desired to determine the document size before reading, the length from the first document trailing edge detection position after separation to the registration sensor position before reading should be at least の of the maximum document length. To configure the transport path. In order to satisfy this condition, the document set position must be largely separated from the reading position, and the portion including the document set table 10 and the transport path becomes large, and the whole apparatus becomes wide. Therefore, in order to make the apparatus small, it is necessary to devise a method for detecting the length of the original when the originals are mixed.

Therefore, in the present embodiment, if the document size cannot be determined before reading in the mixed mode, the document is initially passed without reading the document at all, and the paper path is circulated only for reading the size. In this case, the front surface and the back surface are simultaneously read at the time of passing the second reading position via the reversing unit 4. In this case, the transport operation up to the first stop of the registration is the same as when a document of the same size is bundled, but the operation after receiving the read start signal transmitted from the main body control unit (particularly, the paper discharge unit 7 and subsequent processes) is different. .

As shown in FIGS. 11 to 16, when the document is discharged after passing the reading position on the front or back surface, the reversal switching is performed before the leading edge of the document passes the discharge roller pair 71, 72. The claw 80 is moved in the direction of the broken line by the reversing switching solenoid 105 (step S55), and the document is sent to the switchback path 83 side. After that, the original is
By the pair of reverse discharge rollers 81 and 82 driven by
The document is conveyed until the trailing end of the document passes the pair of discharge rollers 71 and 72. This control is performed by the pulse count from the paper discharge sensor 70 (steps S56 to S66).

After the document is stopped, the reversing switching claw 80 is moved in the solid line direction by the reversing switching solenoid 105, and the rear end of the document is directed to the nip direction of the paper discharge drive roller 71. afterwards,
The reversing discharge drive roller 81 rotates counterclockwise in the counterclockwise direction, abuts the original end (which is the rear end when viewed from the initial state) against the stopped nip portion of the reversing roller pair 71, 83a, and performs the leading end skew alignment operation. Is performed (steps S67 to S69). Thereafter, the pair of reversing rollers 71 and 83a starts conveyance by the reading motor 103, and again,
Are sent to the first reading and conveying unit 5 and the second reading and conveying unit 6 to read the front and back surfaces (Steps S70 to S79).

At this time, since the original is in a state where the back and front are reversed, the reading order is the back and the front is read later. Therefore, the back gate ON signal is transmitted first, and then the front gate ON signal is transmitted. It is transmitted (step S80 to step S84). On the basis of this signal, the image processing unit performs a page order change process.

The reading operation has been completed, but if the sheet is discharged as it is, the page order will not be aligned, so the reversing operation is repeated once and the sheet is discharged (step S85 to step S120).

The transport for only reading the size and the transport for only the page alignment are configured so that the transport is performed at the maximum speed of the apparatus for the transport operation without reading the image, thereby reducing the loss time. (Steps S56 and S104).

Next, a reading operation in a configuration without the second reading and conveying unit 6 will be described.

FIG. 1 shows a configuration in which the second reading and conveying unit 6 is provided to cope with a two-sided original. However, since this device is expensive, the reversing mechanism ( The reversing unit 4) may be used to process a two-sided document. In this case, the document whose front surface has been read by the first reading and conveying unit 5 passes through the reversing conveying unit 8 and the reversing unit 4 again, and
The sheet is conveyed to the first reading / conveying section 5 to read the back side, and then discharged to the stack section 9 through reverse discharge of page alignment.

In the configuration without the second reading / conveying unit 6, productivity is reduced when making a two-sided copy from a two-sided original. Therefore, a plurality of originals are fed into the unit, and image reading and original reversal are performed. The discharge is alternately combined to reduce inter-sheet loss.

First, the first document is fed into the transport path, the first reading and transporting section 5 reads the image of the first page, and then sends it to the reverse transporting section 8 where the reverse roller pair 7 is fed.
The sheet is sent to the first reading / conveying section 5 again after abutting and aligning to the first and the second reading section 83a, and after reading the second page, is sent to the reversing section 4 to align the page order at the time of sheet ejection. Before and after this, the second original is sent, and the first reading / transporting unit 5 sends the third original.
The page is read. Subsequently, the reverse discharge of the first document is executed. Subsequently, after reading the fourth page of the second document, the second document is sent to the reversing unit, and before and after this, the third document is sent, and the reading of the fifth page is performed. Execute. Subsequently, the reverse discharge of the second document is performed.

As described above, by performing processing between the reading of the front side and the reading of the back side with the reversal discharge operation of the already read original interposed therebetween, the inter-sheet loss time of the reversal discharge operation without reading is reduced. It is possible to minimize it. This processing can be performed only on a document having a length that can fit between the pair of reverse discharge rollers 81 and 82 and the registration sensor 40.

Further, the timing control of the next original advance operation (shown in FIGS. 7 and 8) in this embodiment will be described in detail with reference to FIG. FIG. 17 shows the conveyance speed and the elapsed time of the next original advance operation and the reading operation.

The first advance has already been completed, and the apparatus waits for the start signal to be input from the main body control unit 111 at the registration position.
The first document is conveyed downstream by the reading motor 103 driven by the start signal, and is conveyed at a constant reading speed at least before the leading edge of the document reaches the reading position. This control is performed by the reading motor 103
Is performed by the pulse count of

When the reading of the n-th document is started and the trailing edge is detected by the abutting sensor 29, the advance operation of the (n + 1) -th document is started, and at the same time, the timing for driving the registration roller 30 is determined. Paper interval pulse count for determination (pulse count of reading motor 103)
Is started.

In the advance operation of the next original, the reading / conveying roller 43 during reading of the original image is driven by the reading motor 103 at a speed corresponding to the reading magnification instructed from the main body control unit 111. It must be fed into the nip between the reading and conveying roller 43 and the pressure roller 35 at the same speed as the speed of the reading and conveying roller 43. Therefore, as shown in FIGS. 7 and 8, when the trailing edge of the original being read passes through the abutment sensor 29, a pulse count for controlling the sheet interval is started to determine the progress of the trailing edge of the original being read. While monitoring (YES in step S122,
In step S123, advance feeding of the next document is started.

First, the advance operation is performed first.
Then, the pickup roller is pressed against the upper surface of the next original by the forward rotation of the document, and then the paper feed motor 102 is driven to rotate forward to carry the sheet until it hits the stopped registration roller 30 (steps S124 to S127). Here, the rear end position of the original being read is calculated from the inter-sheet pulse count value,
The feed motor 102 is driven to rotate in the reverse direction when a predetermined sheet interval has elapsed from the registration unit 3 (step S128 to step S128).
138), the registration roller 30 is driven at a higher speed than the reading speed, is sent to the tip sensor 34 at this speed, and is decelerated to the reading speed (the speed of the reading and conveying roller 43) by the detection of the tip sensor 34 (step S1).
39 to step S142).

Thereafter, the (n + 1) th original is sent to the nip portion between the reading and conveying roller 43 and the pressure roller 35, stops at a position where a predetermined pulse has been conveyed from the detection of the registration sensor 40, and outputs a registration stop signal to the main controller. 111 (step S143 to step S149), and the main body controller 1
It waits for the input of a read start signal (signal transmitted at the time of preparation for synchronizing with the transfer paper or storing in the image memory) from the CPU 11.

Since the shorter the time t1 from the end of reading the n-th image shown in FIG. 17 to the stop of the (n + 1) -th resist, the higher the production efficiency is, the time becomes almost "0" at this time. In addition, the inter-sheet pulse count for determining the timing for driving the registration roller 30 is controlled. In addition, the time t2 is set so that the leading edge of the document hits the registration roller 30 and enters the nip in the longest time, in theory, so as to absorb variations in conveyance of the separation sheet feeding unit 2 to the registration roller 30. Is also set to be at least larger than “0”, and t
The feeding speed and the feeding timing of the separation sheet feeding unit 2 are controlled by the calling motor 101 and the sheet feeding motor 102 so that the sheet feeding number 2 can be secured.

As described above, during the reading operation of the n-th sheet, (n
The (+1) -th sheet is first advanced and temporarily stopped, and the initial sheet interval (the interval between the n-th sheet and the (n + 1) -th sheet when the (n + 1) -th sheet is advanced) becomes a predetermined value by the n-th sheet reading operation. After the two documents are separated from each other, the control is performed so as to reduce the initial sheet interval. Therefore, the control is simpler than in the method of transporting the document while keeping the interval between the two documents constant.

In this embodiment, the abutment sensor 29 and the like constitute the trailing edge detecting means, the leading edge sensor 34 and the like constitute the leading edge detecting means, and the original setting section 1 and the separation sheet feeding section 2 constitute the separation sheet feeding means. The reading and conveying roller 43 and the pressing roller 3
5, 41, etc. constitute the reading and conveying means, the registration rollers 30 and the like constitute the intermediate conveying means,
1. The sheet feeding motor 102, the reading motor 103, and the like constitute a driving unit, and the control unit (the controller 100, the main body control unit 111, and the like) constitutes the driving control unit.

[0094]

According to the first aspect of the present invention, during the reading of the previous document, the next document is separated and fed and made to stand by, and the next document and the previous document being read are separated from each other by a predetermined distance. Is reached, the next document is transported to a predetermined position upstream from the reading position at a speed higher than the transport speed at the time of reading, and the interval between the preceding and following documents is shortened, so that the transport between the two documents is kept constant. Compared to the simpler control, regardless of the separation method,
It is possible to shorten the interval between the original sheets opened at the time of separating and feeding the next original in the operation of reading the previous original, thereby performing an efficient transport operation.

According to the second aspect of the present invention, the next original is separated and fed while the previous original is being read, and is made to stand by. The next original is read based on the interval between the next original and the previous original being read. Is transported to the reading / transporting means at a speed higher than the predetermined speed, so that the interval between the documents once extended in the preceding document reading operation is reduced during the intermediate transport, so that the transport between the two documents is kept constant. In comparison with the above, the inter-document sheet opened at the time of separating and feeding the next document by the reading operation of the previous document is shortened by the intermediate conveyance means (registration roller 30 or the like) regardless of the separation method by simpler control. An efficient transport operation can be performed.

According to the third aspect of the present invention, based on the detection information of the leading edge detecting means (leading edge sensor, etc.) for detecting the leading edge of the next document, the leading edge of the next document is read and transported by the reading and transporting means (reading and transporting rollers 43, 43). Before reaching the pressure rollers 35, 41, etc.), the intermediate conveyance means is driven so as to convey the next original at a speed equivalent to the conveyance speed of the reading / conveying means. This does not occur, and the transfer of the document between the intermediate transport unit and the read transport unit is performed smoothly.

According to the fourth aspect of the present invention, a trailing edge detecting means (abutting sensor 29) for detecting the trailing edge of the preceding original document.
And the like, and the next document which is separated and fed and is on standby is conveyed to the reading and conveying means, so that the interval between the originals conveyed to the reading position by the reading and conveying means can be kept constant.

According to the fifth aspect of the present invention, during the reading of the previous document, the feeding of the next document by the separation sheet feeding means is completed before the conveyance of the next document by the intermediate conveyance means is started. It is possible to absorb a variation in conveyance from the document feeding and separation feeding in the sheet feeding means (the document setting unit 1 and the separation sheet feeding unit 2) to the start of the intermediate conveyance, and to maintain a constant document interval during the reading conveyance.

That is, according to the present invention, it is possible to provide an automatic document feeder capable of maintaining a constant document sheet so that the production efficiency is maximized regardless of the separation method.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an automatic document feeder according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control unit of a copier equipped with the automatic document feeder of FIG. 1;

FIG. 3 is a diagram showing a configuration of a contact image sensor of a second reading and conveying unit in the automatic document feeder of FIG. 1;

FIG. 4 is a part of a flowchart showing a sheet feeding operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 5 is a part of a flowchart showing a sheet feeding operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 6 is a part of a flowchart showing a sheet feeding operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 7 is a part of a flowchart showing a next original advance operation of the automatic original feeder according to the embodiment of the present invention.

FIG. 8 is a part of a flowchart showing a next original advance operation of the automatic original feeder according to the embodiment of the present invention.

FIG. 9 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 10 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 11 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 12 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 13 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 14 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 15 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 16 is a part of a flowchart showing a reading operation of the automatic document feeder according to the embodiment of the present invention.

FIG. 17 is a timing chart showing a conveyance speed and a lapse of time of a next original advance operation and a reading operation of the automatic original conveyance device according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 document setting section 2 separation feeding section 3 registration section 4 reversing section 5 first transport reading section 6 second transport reading section 8 reverse transport section 20 pickup roller 29 butting sensor 30 registration roller 32 size sensor group 34 tip sensor 35, Reference Signs List 41 pressure roller 40 registration sensor 43 reading and conveying roller 61 contact image sensor 100 controller 101 calling motor 102 paper feeding motor 103 reading motor 111 main body control unit 200 automatic document feeder (ADF)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/00 108 G06F 15/64 325E 5C071 1/04 H04N 1/12 A (72) Inventor Toshiaki Kameyama Tokyo 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hideki Tobinaga 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Motoya Sano Naka, Ota-ku, Tokyo 1-3-6 Magome Inside Ricoh Co., Ltd. (72) Inventor Shinya Takai 2-2-13 Nishiki, Naka-ku, Nagoya-shi, Aichi Ricoh Elemex Corporation (72) Inventor Toru Horio Naka-ku, Nagoya-shi, Aichi Nishiki 2-chome 2-13 Ricoh Elemex Co., Ltd. F-term (reference) 2H076 AA04 AA58 BA24 BA63 BA68 BB10 3F049 DA12 EA10 EA13 EA14 EA23 EA28 LA02 LA11 LB02 3F102 AA03 AB01 BA02 BB02 CA01 CB01 DA08 FA06 FA08 5B047 AA01 BA01 CA08 CA09 CB06 5C062 AA05 AB31 AB32 AC12 5C072 AA01 BA03 NA05

Claims (5)

[Claims] A separating and feeding means for separating and feeding the originals one by one from an original bundle comprising a plurality of stacked originals; a reading and conveying means for conveying the fed originals to a reading position; A driving unit that drives the separation sheet feeding unit and the reading and conveying unit; and a driving control unit that controls the driving unit. When the current document and the previous document being read are separated from each other and reach a predetermined interval, the next document is transported to the predetermined position upstream of the reading position at a speed higher than the transport speed at the time of reading, and the interval between the preceding and following documents is reduced. An automatic document feeder. A separating and feeding means for separating and feeding the documents one by one from a document stack comprising a plurality of stacked documents, and a predetermined position from a predetermined position upstream of the reading position to a reading position for the conveyed documents. Reading and conveying means for conveying at a speed, an intermediate conveying means for conveying the separated and fed document to the reading and conveying means, a driving means for driving the separating and feeding means, the reading and conveying means, the intermediate conveying means, and the driving means And a drive control means for controlling the following, while reading the previous original, separating and feeding the next original and making it stand by; based on the interval between the next original and the previous original being read, An automatic document feeder, wherein the document is conveyed to the reading / transporting means at a speed higher than the predetermined speed, thereby shortening the document interval once extended in the preceding document reading operation during the intermediate conveyance. 3. An upstream end detecting means for detecting the next leading edge of the original, which is located upstream of the intermediate transporting means, based on information detected by the leading edge detecting means, before the next leading edge of the original reaches the reading transporting means. 3. The automatic document feeder according to claim 2, wherein the intermediate feeder is driven so as to feed the next original at a speed equal to the feed speed of the reading feeder. And a rear end detecting means for detecting a rear end of the preceding document downstream of the separating sheet feeding means, and a next sheet which is separated and fed and is on standby based on detection information of the rear end detecting means. 4. The automatic document feeder according to claim 3, wherein the document is transported to a reading transport unit. 5. The method according to claim 4, wherein during the reading of the previous document, the feeding of the next document by the separation sheet feeding means is completed before the conveyance of the next document by the intermediate conveying means is started. Automatic document feeder.