JP3365214B2 - Document feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder, and more particularly to picking up a plurality of stacked documents one by one and feeding the documents at a constant speed on an image reading position of an image reading device in a stationary state. The present invention relates to a document feeder.

[0002]

2. Description of the Related Art Conventionally, as described in U.S. Pat. No. 5,461,468, a raster input scanner is fixed at a reading position and an original is placed on the reading position.
2. Description of the Related Art There is known a so-called follow shot type document conveying device that conveys a document at a constant speed and reads a document image with a scanner. In this document feeder, the documents stacked on the tray are picked up by a nudger roller that descends for each sheet feeding, separated by a first conveying roller and a reverse roller, and read by a takeaway roller and a registration roller. The document is conveyed toward the sheet, the skew of the document is corrected, and the document is conveyed at a constant speed on the reading position by a plurality of constant speed rollers. Further, in order to reduce the document conveyance interval, the major roller, the first conveyance roller and the takeaway roller are driven at a relatively high speed, and the speed is reduced when the leading edge of the document reaches the registration roller. The registration roller and the constant speed roller are driven at the same rotation speed.

[0003]

By the way, in the follow shot type document conveying apparatus having the above-mentioned structure, the registration roller installed further upstream than the constant speed roller installed immediately before the reading position. Since the skew of the original is corrected and the leading edge of the original is positioned, skew of the original may occur after the registration roller.
This causes a problem that the document is conveyed at the reading position without correcting the skew feeding. In addition, the fact that the registration roller is far from the reading position causes a limitation in reducing the document feeding interval because the skew feeding of the next document cannot be corrected during reading. Further, if the next original enters the registered registration roller during reading, the driving load of the original increases instantaneously, the constant-speed conveyance property is impaired, and the reproducibility of the original image deteriorates.

Therefore, an object of the present invention is to prevent a document from being conveyed in a skewed state at the reading position and to reduce the document conveyance interval without impairing the constant speed conveyance property. An object is to provide a photographing type document feeder.

[0005]

The constitution, operation and effect of the present invention have been achieved.
Therefore, the document feeder according to the first invention is configured to read a document image.
Scanning device near the feeding position and the paper feeding
Carry the paper means and the fed document toward the reading position.
The first feeding means for feeding and the original at a constant speed on the reading position.
Second transporting means for transporting with the first transporting means and the second transporting means
The document detection sensor provided between the document feeding means and the document,
When the detection sensor detects the trailing edge of the document, the next document is fed.
And a paper feed starting means for starting, And the following equation
Be satisfied. (L _A / V _A ) <(L _B / V _B ) Note that L _A Is the distance between the sensor and the reading position, V _A Is the second transport
Transport speed by means, L _B Is the first carrier to the second carrier
Step distance, V _B Is the transport speed by the first transport means.
Further, the document feeder according to the second aspect of the present invention reads the document image.
Documents are fed with the reading means stationary near the picking position
Direct the paper feed unit and the fed original to the reading position.
It is placed immediately before the reading roller and the feeding roller for feeding.
And a first roller that is disposed immediately after the reading position,
The original is conveyed at the reading position at the same speed as the first roller.
Between the second roller and the transport roller and the first roller
The document detection sensor provided on the
Stop when the first position is passed
Means and the document detection sensor detect the trailing edge of the document.
And a paper feed starting means for starting the feeding of the next document., Equipped
In addition, the following expression is satisfied. (L _A / V _A ) <(L _B / V _B ) Note that L _A Is the distance between the sensor and the reading position, V _A Is the first row
La, conveyance speed by the second roller, L _B Is the transport roller
Distance between rollers, V _B Is the transport speed by the transport roller
It The document feeder according to the third aspect of the present invention is a stack pick-up device.
Conveyed up originals toward the image reading position
Transport roller and the downstream side of this transport roller.
The first roller located immediately before the reading position and the reading position
The second roller positioned immediately after the placement, the transport roller and the first roller.
And a document detection sensor located between the
The leading edge of the document conveyed by the feed roller stops rotating.
Of the transport roller for a predetermined time even after the contact with the first roller
A first control step of continuing driving, and the first roller,
Second rollerAfter the document is fed over the reading position by
Stops driving the first roller when the edge passes the reading position.
And based on the document trailing edge detection signal from the sensor
Second control step to start picking up the next original
Then, the following equation is satisfied. (L_A/ V_A) <(L_B/ V_B) Note that L_AIs the distance between the sensor and the reading position, V_AIs the first row
La, conveyance speed by the second roller, L_BIs the transport roller
Distance between rollers, V_BIs the transport speed by the transport rollerIn degreesAh
It

Document transporting apparatus according to the first and second inventions
When Oite, the trailing edge of the document has been fed to the previously detected by the sensor, since the sheet feeding of the next document is started, as short as possible the distance between the document conveyed continuously, and Thus, it is possible to convey continuously fed originals at the reading position without fear of overlapping. In addition, satisfying the above equation
Therefore, reading efficiency can be improved. In the document conveying apparatus according to the third aspect of the invention, the document picked up from the stack is conveyed by the conveying roller, abuts on the first roller that is not rotating to correct skewing, and then the reading position is read by the first roller. Be transported to. Since the first roller is installed immediately before the reading position, the skew-corrected document is conveyed from the first roller to the reading position without skewing. Further, when the trailing edge of the preceding document passes the reading position, the driving of the first roller is stopped, and when the trailing edge of the preceding document is detected by the sensor, the conveyance roller starts to convey the next document. . Therefore, a plurality of originals can be conveyed with a small interval one after another without overlapping the two originals at the reading position. That is, it is possible to set the conveyance interval of the document within the range between the distance between the first roller and the reading position and the distance between the sensor and the reading position ,
The reading efficiency can be improved.

In the embodiment described below,
The transport roller defined in the present invention means the paper feed roller 2103, the first and second rollers mean the first and second reading roller pairs 2201 and 2203, and the original detection sensor means the width size reference sensor SE6. Means

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a document feeder according to the present invention will be described below with reference to the accompanying drawings. The embodiment described below is installed in an electrophotographic copying machine.

(Schematic Structure of Copying Machine Main Body) Copying machine main body 10
Is mainly composed of an image reading optical system 11, a laser optical unit 13, an image forming section 14, and a sheet feeding section 15.

(Image reading optical system) Reading optical system 11
Is disposed immediately below the platen glass 111 constituting the upper surface of the main body 10, and illuminates the original set on the platen glass 111, the reflection mirror 113,
Lenses 1 and 114 having a focusing function and a zooming function
16, a CCD sensor 117, and a shading correction plate 119 arranged on the platen glass 111 to correct the sensitivity variation of the CCD sensor 117.

A document scale 101 for positioning a document on the platen glass 111 is arranged at the left end of the platen glass 111. The operator lifts the original document conveying device 20 described below, and with the original document surface facing downward, one end of the scale 10
1 and set on the platen glass 111.
In the reading optical system 11, the lamp 112 and the mirrors 113, 114, 115 move in the direction of arrow b while irradiating the original with the lamp 112, scan the original image, and scan the lens 1
It is read by the CCD sensor 117 via 16. The CCD sensor 117 first reads the reflected light from the shading correction plate 119, and corrects the sensitivity variation of each pixel of the sensor 117. After that, scanning of the document image is started from the document reference position SP.

The exposure lamp 112 and the mirror 113 have a peripheral velocity V of the photosensitive drum 121 (constant regardless of equal magnification or variable magnification).
In contrast, the moving speed is V / m (m is a copy magnification) in the direction of arrow b. At the same time, the mirrors 114 and 115 are V / 2m
It moves in the direction of arrow b at the speed of. Thus, the image is read while keeping the optical path length during scanning constant.

On the other hand, at the right end of the platen glass 111, a slit glass 1 for reading an image of a document conveyed at a constant speed by a document conveying device 20 described below.
98 are arranged. In order to perform this reading, the lamp 112 and the mirror 113 are made stationary under the slit glass 198, and the mirrors 114, 115 are also made stationary at the position where the required optical path length is formed. Slit glass 1
Illumination light is applied from a lamp 112 to an original document passing through 98 at a constant speed (which is changed according to the copy magnification m), and the image is read by a CCD sensor 117. Slit glass 1
A guide plate 199 arranged at the left end of 98 is for picking up the document from the slit glass 198.

Manually copy the original on the platen glass 111
A configuration is known in which the document conveying device 20 can be lifted upward because it is set on the top. For the document of a standard size, the above-described follow shot is performed using the document feeder 20. When a document having an inappropriate material or size for using the document feeder 20 is manually set on the platen glass 111, the image is read by scanning the reading optical system 11.

(Laser optical unit) CCD sensor 11
With respect to the image read in 7, the laser optical unit 13 outputs an image, and an electrostatic latent image is formed on the photosensitive drum 121. That is, the image data read by the CCD sensor 117 undergoes various processes in the image processing unit 12 to be generated as print data, and the laser diode 13
1 is modulated and emitted. The laser beam emitted from the laser diode 131 is deflected by the polygon mirror 135 rotating at a high speed, and the lenses 136 and 1 having the fθ function.
37, and the reflection mirrors 138a, 138b, 138
The photosensitive drum 121 is exposed through c.

(Image Forming Section) The image forming section 14 includes a charging charger 122, a developing device 123, a transfer charger 124, a charge removing charger 125, a sheet around the photosensitive drum 121 along the rotation direction indicated by an arrow a. Separation claw 1
26, a residual toner cleaner 127, and a residual charge eraser 128 are arranged. Since the configuration and operation of each of these elements are well known, description thereof will be omitted.

(Sheet Feeding Section) Copy Sheet Feeding Section 1
5 is a cassette 151, 152, 15 accommodating sheets
3 and a sheet conveying path and the like. A pickup roller 154, a paper feed roller 155, and a separation roller 156 are arranged in each of the cassettes 151, 152, and 153 provided in three stages.

The size of the document manually set on the platen glass 111 is detected by the sensors SE31, 32 and the like. Optimal size sheets are conveyed from the cassettes 151, 152, 153 based on the detected size, and the selected sheets are fed one by one based on the sheet feed signal. The fed sheet is conveyed by the conveying roller 171,
It is conveyed upward by 172 and 173, and is temporarily stopped by the timing roller 174. Thereafter, the timing roller 174 is rotationally driven in synchronization with the image formed on the photosensitive drum 121, and the sheet is conveyed to the transfer portion.

The sheet on which the toner image has been transferred at the transfer portion is immediately separated from the photosensitive drum 121, and the conveyor belt 1
The toner is fed between the fixing rollers 176 and 177 by 75, and the toner is fixed there. Thereafter, the sheet is discharged from the discharge roller 178 to a tray or sorter outside the machine.

Further, the copying machine main body 10 is provided with a transport section 18, a switchback section 19 and a refeed section 16 which branch off from just before the sheet discharge roller 178. The transport unit 18 includes a switching claw 181, a transport roller 182, and a sheet guide plate 18
4, 185. Switchback part 19
Is composed of a forward / reverse rotatable conveyance roller 191, a roller 192 that follows it, a conveyance roller 193, a sheet guide plate 194, and a sheet detection sensor SE41. In addition, a flexible resin film 197 is provided at the boundary between the transport unit 18 and the switchback unit 19 so as to prevent backflow of the sheet. The sheet re-feeding unit 16 includes the transport rollers 141 and 142 and the sheet guide plates 143 and 14
It is composed of 4 and.

When the double-sided copy mode is executed, the copy sheet having the image transferred on the first side is conveyed by setting the switching claw 181 to a position where it is slightly rotated counterclockwise from the solid line position in FIG. It is introduced into the switchback unit 19 through the unit 18. When the leading edge of the copy sheet is detected by the sensor SE41, the transport roller 191 is normally driven in the direction of arrow c. Further, when the rear end of the copy sheet is detected by the sensor SE41, the transport roller 191 is driven to rotate in the reverse direction of the arrow c. As a result, the copy sheet is turned upside down / frontward / backward, guided by the resin film 197, conveyed to the re-feeding unit 16, and re-fed to the timing roller 174. The image is transferred to the second surface of the re-fed copy sheet, and the paper is discharged from the discharge roller 178.
Is discharged to the outside of the main body 10.

(Copy Mode) The copying machine body 10 described above
In the above, there are an APS mode, an AMS mode, and a manual mode as basic copy modes in combination with the document feeder 20. The APS mode is an automatic paper selection mode in which the copy sheet size is automatically determined based on the copy magnification selected by the operator and the detected document size, and copy processing is executed. The AMS mode is an automatic magnification selection mode in which the copy magnification is automatically determined based on the copy sheet size selected by the operator and the detected document size, and the copy process is executed. The manual mode is a mode in which the copy process is executed with the copy sheet size and the copy magnification selected by the operator regardless of the document size.

Further, in the copying machine main body 10, after the original image is read by the reading optical system 11 and stored in the image processing unit 12, the image is rotated by processing the print data to the laser optical unit 13. It has a function of processing in the 2in1 mode and the 4in1 mode. That is, even when the setting direction of the copy sheet is different from the setting direction of the original, the image can be rotated by 90 ° on the horizontal plane to match the setting direction of the copy sheet.
The 2in1 mode means that two original images are reproduced on one sheet, and the 4in1 mode means that four original images are reproduced on one sheet.

Further, independently of each of the copy processing modes, there are a non-mixed loading mode in which originals of the same size are continuously read, and a mixed loading mode in which originals of different sizes are read continuously even when the setting directions are different. It is feasible. When the non-mixed loading mode and the APS mode or the AMS mode are selected at the same time, the copy process is executed based on the size of the first original, so that the sheet feeding operation for the second and subsequent sheets is quickly processed, and the manual operation is performed. A copy productivity almost equal to that of the mode is secured. On the other hand, if the mixed mode and the APS mode or the AMS mode are selected at the same time, the copy process is executed based on the document size detected for each document.

(Outline of Document Conveying Device) As shown in FIG. 2, the document conveying device 20 is composed of the following main parts. Paper feed unit 2100: document tray 2101, pickup roller 2102, paper feed roller 2103, separation roller 210
4 and an intermediate conveyance roller pair 2105. Reading unit 2200: a first reading roller pair 2201, a pressure contact guide plate 2202, a second reading roller pair 2203, an introduction guide plate 2204, and an exit guide plate 2205.

Circulation reversing section 2300: switching claw 2301,
A circulation reverse roller pair 2302 and a circulation conveyance path 2310 are provided. Paper output reversing unit 2400: a switching claw 2401 and a paper output reversing roller pair 2402. Paper ejection unit 2500: paper ejection roller pair 2501, paper ejection tray 2
502 is provided. Manual feed unit 2600: A manual feed tray 2601 and a manual insertion slot 2602 are provided. Document holding plate 2802: Holds a document set manually on the platen glass 111.

Further, the document feeder 20 is for a single-sided document mode for reading an image of a single-sided document having an image only on one side, and for reading an image of a double-sided document having images on the first and second sides. 2-sided original mode and paper feed unit 2
100 has a single paper feed mode for processing a document of a type that is not suitable for automatic separation and feeding.

(Structure of Paper Feeding Section) The original tray 2101 has an inclined portion 2101a in the front half thereof, and the inclined portion 2101
A tip regulation plate 2111 is installed at the tip of a. The lift-up plate 2107 is installed so as to be movable up and down with its left end as a fulcrum, and is usually located on the same plane as the inclined portion 2101a.

The original is set on the tray 2101 with its leading end aligned with the regulation plate 2111. When the lift-up plate 2107 moves up in conjunction with the drive lever 2108 moving up by the lift-up motor, the uppermost surface of the original comes into pressure contact with the pickup roller 2102. The pick-up roller 2102 is installed via an arm 2116 so as to be vertically movable around a support shaft of the paper feed roller 2103 as a fulcrum, and is urged downward by its own weight and a spring (not shown). The pickup roller 2102 is the drive lever 2
When the lift-up plate 2107 is lifted by 108, the lift-up plate 2107 is lifted in association with the lift-up plate 2107. Upper limit sensor SE
The detection state of the sensor 15 is constantly monitored, and when the pickup roller 2102 descends and the sensor SE15 enters the non-detection state, the drive lever 2108 lifts the lift-up plate 210.
Raise 7. With this, the pickup roller 210
The reference numeral 2 picks up a document with a predetermined height and a predetermined pressure contact force, and the document is fed from a predetermined height. This means that regardless of the remaining amount of the document, the leading edge of the document comes into contact with the pre-sorting guide piece 2110a at a predetermined angle and height to ensure stable sheet feeding.

The front separating guide piece 2110a is a holder 211.
The upper end of the leading edge regulating plate 2111 is arranged in an ascending slope, and its leading edge is close to the nip portion between the sheet feeding roller 2103 and the separating roller 2104 with a slight gap. A plurality of originals are fed by the pickup roller 2102, and the leading end of the originals is brought into contact with the front separating guide piece 2110a so that the upper originals are separated so that only two or three originals are transferred to the roller 21.
It plunges between 03 and 2104.

The paper feed roller 2103 is driven to rotate in the counterclockwise direction, and among the plurality of originals which are projected between the rollers 2103 and 2104, one of the uppermost layers is conveyed rightward by the roller 2103 and the other originals are conveyed. The roller 2104 prevents its progress. That is, the paper feed roller 2103 is shown in FIG.
The separation roller 2104 is rotatably driven at a fixed position shown in (1) and is rotatably mounted on the holder 2110, and is elastically pressed against the sheet feeding roller 2103 via the holder 2110 by a spring (not shown). A torque limiter is attached to the separating roller 2104. The torque of the torque limiter is set by the roller 210 when the paper feed roller 2103 rotates.
If only one document is present between 3,2104,
The separation roller 2104 is set to a value such that it is driven and rotated in the clockwise direction by the frictional force between the separation roller 2104 and the document conveyed by the paper feed roller 2103. When a plurality of originals are projected between the rollers 2103 and 2104, the separation roller 2104 is stopped, and an original located below the uppermost original conveyed by the paper feed roller 2103 is prevented from entering.

(Original Paper Feeding Operation) Originals are stacked on the original tray 2101 with the first page facing upward, and a copy start key (not shown) is pressed by the operator (feeding of the first sheet). Paper), original tray 21
When the actuator lever 2106 on 01 is pushed to the original and the empty sensor SE1 is in the original detection state (when feeding the second and subsequent sheets), the pickup roller 2102 is rotationally driven counterclockwise at a predetermined timing. , Send the document to the right in FIG.

The picked-up original is preliminarily separated by the front separating guide piece 2110a and is separated into one sheet by passing between the paper feeding roller 2103 and the separating roller 2104. Subsequent document conveyance will be described separately for a single-sided document and a double-sided document.

(Single-Sided Original Mode) The original separated into one sheet is then conveyed by a pair of intermediate conveying rollers 2105. The pair of intermediate conveyance rollers 2105 has a predetermined time after the leading edge of the document is detected by the registration sensor SE2, that is,
The first reading roller pair 22 in which the leading edge of the document has stopped rotating
The rotation is stopped when it comes into contact with the nip portion of 01 and bends by an appropriate amount. As a result, the leading edge of the document is aligned at the nip portion of the first reading roller pair 2201 and skew is corrected.

Next, the reading roller pairs 2201 and 2032
Is rotated, the original is conveyed on the slit glass 198 while being pressed against the guide plate 2202. At this time, the original image is read by the reading optical system 11. The pair of intermediate conveying rollers 2105 is rotationally driven until the trailing edge of the original passes through the nip portion. Further, the document is switched from the second reading roller pair 2203 to the switching claws 2301 and 243.
The sheet is guided to the left by the lower surface of the sheet 01, and is discharged onto the sheet discharge tray 2502 from the pair of sheet discharge rollers 2501 with the image surface facing downward. The feeding of the next document is performed based on the fact that the trailing edge of the previous document is detected by the sensor SE6 (described below).

By the way, the reading roller pairs 2201 and 22
The rotation speed of 03 is changed based on the copy magnification, and the rotation speed of the intermediate conveyance roller pair 2105 is also changed. Assuming that the copy magnification is m and the transport speed of the reading roller pairs 2201 and 2033 at the same magnification is V (equal to the rotational peripheral speed of the photosensitive drum 121), the reading roller pair 2201.
The conveyance speed 2203 is automatically set to Vm described later.

The image reading by the reading optical system 11 is started after a lapse of a fixed time after the reading sensor SE14 installed immediately after the first reading roller pair 2201 detects the leading edge of the document. That is, after the sensor SE14 detects the leading edge of the document, the drive amount of the drive motor M2 (described below) of the reading roller pair 2201 and 2032 is monitored to determine the timing at which the leading edge of the document reaches the reading position 190. The reading operation is started by counting.

(Manual Feeding) The manual insertion slot 2602 is
It is formed on the upstream side of the first reading roller pair 2201 and is opened by tilting the manual feed tray 2601 outward. At this time, the operator inserts the original into the insertion port 2602.
When the first reading roller pair 2201 is brought into contact with the nip portion of the first reading roller pair 2201, the reading roller pair 2201 and 2203 are rotatably driven to be conveyed on the slit glass 198 in the same manner as the single-sided original, and the image is read. The rotation of the reading roller pairs 2201 and 2033 is started when a predetermined time has elapsed after the leading edge of the inserted document was detected by the registration sensor SE2.

(Double-sided original mode) As described above, the double-sided original fed from the original tray 2101 is conveyed on the slit glass 198 by the pair of reading rollers 2201 and 2203 to read the image on the first side. . At this time, the switching claw 2301 is set to a position slightly rotated clockwise from the position shown by the solid line in FIG. Therefore, the first
The document on which the surface image is read is conveyed to the circulation reversing roller pair 2302 while being guided by the inclined surface of the switching claw 2301. Backflow prevention resin film 2304
After passing through, the reversing roller pair 2302 is reversely driven, and the document is fed to the circulation conveyance path 2310 with its front and back reversed. After that, the original is turned upside down and conveyed toward the first reading roller pair 2201, and the leading end of the original comes into contact with the nip portion of the first reading roller pair 2201 whose rotation is stopped, and when it is bent by an appropriate amount, the reverse roller is turned. Pair 2302
Rotation is stopped. This adjusts the consistency of the leading edge of the document and corrects the skew feeding.

After that, the reading roller pairs 2201 and 220
3 is rotationally driven, and the original is conveyed on the slit glass 198 with the second side facing downward, and the image is read on the second side. At this time, the switching claw 2301 has returned to the position shown by the solid line in FIG. 2, and the switching claw 2401 is set at a position slightly rotated clockwise from the position shown by the solid line in FIG. Therefore, the document on which the second-face image reading has been performed is conveyed to the paper discharge reversing roller pair 2402 while being guided by the lower surface of the switching claw 2301 and the upper surface of the switching claw 2401. When the trailing edge of the document passes through the backflow prevention resin film 2403, the discharge reversal roller pair 2402 is reversely driven, and the document is guided by the backflow prevention resin film 2403 with the front / back / front and back reversed and discharged. The sheet is discharged onto the sheet discharge tray 2502 by the roller pair 2501. At this time, the originals are ejected with the first side facing downward, and the page order is aligned. In the double-sided original mode, when the rear edge of the original is detected by the registration sensor SE2 during the second side reading, the feeding of the next original is started.

(Drive system) In order to perform the above operation, as shown in FIG. 5, the paper feed roller 2103 and the intermediate conveying roller pair 2 are used.
105 and the circulation reversing roller pair 2302 are driven by a paper feeding motor M1 that can rotate in the forward and reverse directions. Paper feed roller 210
3 is rotationally driven by the belt 2181 via the clutch CL1. Rotational force is transmitted to the pickup roller 2102 via the paper feed roller 2103. When the document is conveyed by the pair of reading rollers 2201 and 2203,
The clutch CL1 is turned off, and the pickup roller 210
2 and the paper feed roller 2103 are pulled by the document and are driven to rotate. In order to reduce this driven resistance, the roller 210
Two-way clutches are attached to 2, 2103. The intermediate conveying roller pair 2105 is rotationally driven via the belt 2184 and gears 2186 and 2187 without passing through the clutch CL1. The pair of reversing rollers 2302 is the belt 2
It is rotationally driven via 384. Intermediate transport roller pair 21
When the document 05 is driven to rotate in the direction in which the document is conveyed toward the first reading roller pair 2201, the circulation reversing roller pair 2
Reference numeral 302 is rotationally driven in the direction in which the original is conveyed to the upper left.

The reading roller pairs 2201 and 2203 are rotationally driven by the conveying motor M2 via the belt 2283.

The pair of sheet discharge reversing rollers 2402 and the pair of sheet discharge rollers 2501 are rotationally driven via a belt 2484 by a sheet discharge motor M3 which can rotate in the forward and reverse directions. When the pair of discharge reversal rollers 2402 are rotationally driven in the direction to convey the document to the lower right, the pair of discharge rollers 2501 conveys the document to the tray 2502.
It is driven to rotate in the direction of discharging upward.

The document feeder 20 executes the above-described single-sided document mode and double-sided document mode based on the operator's selection. When a plurality of originals are set on the tray 2101, the above-described original feeding / conveying is performed one by one, and when the number of copies (the number of copies) set by the operator is plural, the reading optical system 11 The image data read once is stored in a memory, and a copy process is performed according to the number of copies.

(Detection of Original Size) It is necessary to detect the original size in order to perform various copy processes effectively and quickly in the copying machine main body 10 by using the original conveying device 20. First, on the document tray 2101, the length size of the document is detected as a plurality of types. Therefore, the sensors SE11 and SE12 are installed at the rear end portion of the tray 2101. The lengths of documents can be classified into three types by the sensors SE11 and SE12.

Further, a width size reference sensor SE6 and a width size sensor SE7 are provided immediately after the paper feed roller 2103. As shown in FIG. 6, the document is conveyed in the direction of arrow d with one side aligned with the reference line R. Sensor SE6 has reference line R
Installed on the side, any size original can be detected. The sensor SE7 is installed on the opposite side of the sensor SE6. The sensors SE6 and SE7 are transmissive optical sensors, and the sensor SE6 is the lever 2 that interferes with the document.
The sensor SE7 has a lever 2 that interferes with the document.
131 to 2135 are independently rotatable. These levers 2129, 2131-21
Numerals 35 are arranged in a straight line in a direction orthogonal to the document conveyance direction d and enter the document passage by its own weight.
The operation is performed at the same timing depending on the leading edge of the document conveyed in the direction. The levers 2131 to 2135 correspond to sizes 2, 3, 4, 5 and 6 according to the width size of a standard size document, and the minimum width size 1 operates only the lever 2129 of the sensor SE6. Lever 2129, 2131
2135, as shown in FIG.
2131a to 2135a, the respective light blocking angles are A to F, A = F, and F <E <D <C <
The relationship is set to B. Therefore, when one document passes through the sensors SE6 and SE7, the sensors SE6 and SE7
The detection signal 7 is generated at the timing shown in FIG. By monitoring the presence or absence of these signals and the time differences T ₁ , T ₂ , T ₃ , and T ₄ , the width size of the document can be determined.

In this embodiment, the size detection signal is issued at a later timing from the lever 2135 farther from the paper passing reference line R to the closer one. This is because the discrimination logic shown in FIG. 8 can be applied even when the leading edge of the document on the side opposite to the reference line R is delayed and detected by the sensor SE7 due to the skew of the document. By the way, when the small size detection lever 2131 is sequentially detected, when the skew similar to the above occurs, the lever 2131 operates first despite the large width size and may be erroneously detected as a small width size. There is a nature.

It should be noted that the sensor SE6 is not always necessary and can be substituted by some reference signal. Also,
In addition to the sensors SE11 and SE12, the length of the document may be measured by a sensor (for example, the sensors SE6 and SE6) during conveyance.
It can also be detected by a combination of 2) and a counter.

By the way, the document size controls the copying process in various modes in the main body of the copying machine 10 quickly.
It is preferable to confirm as soon as possible. The document size is the earliest to be detected on the tray 2101. But,
When documents of various sizes are mixed, they cannot be detected on the tray 2101. Therefore, if the sensors SE6 and SE7 are provided immediately after the paper feed roller 2103, the size of the original to be copied next can be detected at the earliest timing. When documents of the same size are set on the tray 2101, the sizes can be determined immediately after the start of the feeding operation of the first document. If different sizes are mixed, the trailing edge of each document is the sensor SE6, S
The size can be determined when passing E7. for that reason,
It is possible to minimize the waiting time before starting the feeding of copy sheets in the copying machine body 10, shorten the first copy time, and improve the copy productivity.

Further, when image data is stored in the main body of the copying machine 10 and the sorting of copy sheets or the processing such as the 2in1 mode or the 4in1 mode is performed, the number of images that can be processed in order to process the image data. Depends on the memory capacity. However, since the memory is expensive, it is often impossible to mount a memory with a sufficient margin. Therefore, by determining the document size before reading the document image, it is possible to process the image data with the minimum required memory capacity without lowering the copy productivity.

However, when different sizes are mixed, the sensor SE
6, the document size cannot be determined until the trailing edge of the document passes, and image reading of the document is started before the document size is determined. Therefore, when the APS mode is selected, conventionally, it was always necessary to secure the memory capacity required for the image data of the maximum size for one document. Further, if the reading is started after the document size is fixed, the document is once passed through the reading unit 2200 and then read again, or the distance between the sensors SE6 and SE7 and the reading position 190 is set to be the maximum size of the document or more. Either will be. However, this cannot avoid a decrease in copy productivity and an increase in the size of the apparatus 20.

As in this embodiment, the width size sensor SE7
If at least the width size is set immediately after the paper feeding roller 2103, at least only the width size can be determined before the reading is started. It is possible to save the memory capacity for doing so and efficiently use the memory. Therefore, regarding the capacity of the installed memory, the number of images that can be processed is greater than in the conventional case, and various image processing is possible.

(Structure of Reading Unit) Here, the reading unit 22
00 will be described in detail. First reading roller pair 2201
It has been described above that is located immediately in front of the slit glass 198 and receives the leading edge of the original conveyed from the intermediate conveying roller pair 2105 at the nip portion thereof and has a registration function for the front end of the original.

The original pressure contact guide plate 2202 faces the slit glass 198 at a constant interval, that is, at an interval slightly larger than the thickness of the original. The guide plate 2202 has a function of guiding the document to the slit glass 198 and preventing the document from floating on the slit glass 198. To ensure this function, a flexible and slippery resin film may be installed from the guide plate 2202 toward the slit glass 198. Further, the slit glass 198 is fixed on the copying machine main body 10, and the guide plate 2202 is attached to the document feeding device 20.
Therefore, when a document jam occurs in the reading unit 2200, the device 20 is lifted up to move the glass 198.
The guide plate 2202 and the guide plate 2202 are separated from each other, which facilitates jam processing.

By the way, in order to obtain a high quality copy image by reading the original image using the original conveying device 20,
In the reading unit 2200, it is necessary that the document is transported at the speed of Vm and that the document is transported so as not to shift from the focus position of the reading optical system 11, that is, in a state of being in close contact with the slit glass 198. .

As described above, the reading roller pair 2201,
2203 is a belt 228 driven by a single conveyance motor M2.
It is rotationally driven in synchronization via 3. Thus, the conveyance speeds of the roller pairs 2201 and 2032 are kept the same, and vibrations of the roller pairs 2201 and 2203 due to mechanical rattling or the like that cannot be avoided in the gear drive system are prevented.
This means that the document can be conveyed at a constant speed and a stable image can be read. Further, by making the driving of the reading roller pairs 2201 and 2203 independent of the other conveying system, mixing of noise due to load fluctuation of the other conveying system is blocked, and the constant speed conveying property of the roller pair 2201 and 2032 is improved. become.

The outer diameters of the reading roller pairs 2201 and 2032 are the same (the conveyance speeds are the same),
Basic and best. However, when the conveyance speed of the second reading roller pair 2203 on the downstream side becomes slower than that of the first reading roller pair 2201 on the upstream side, the document on the slit glass 198 sags, and the document dances or the image surface is changed. The reading optical system 11 is out of focus and adversely affects reading of an image. Therefore, the second reading roller pair 2
It is preferable to maintain the relationship of the transport speed of 203 ≧ the transport speed of the first reading roller pair 2201.

Further, the reading roller pairs 2201 and 2032
As shown in FIG. 5, one of the rollers 2201a, 221a, 22
03a, and the other rollers 2201b and 2203b
Is driven to rotate. Driven rollers 2201b, 220
In 3b, the method of forcibly driving the driving rollers 2201a and 2203a with a gear or the like is advantageous in terms of preventing slips on the original, but on the other hand, a load fluctuation occurs due to the impact of the teeth of the gear, causing a problem of fluctuations in the conveyance speed. .
In the present embodiment, the driven roller 22 places importance on the constant speed conveyance property.
01b and 2203b to drive rollers 2201a and 2203
We adopted a method to rotate the driven wheel by friction with a or the original.

Further, drive rollers 2201a and 2203
a is a rubber material having a high friction coefficient (for example, EPDM, PU
R), but the rubber hardness was set high (about 70 to 90 degrees). The driving rollers 2201a and 2203b are driven by the fluctuations and eccentricities of the pressure contact forces of the driven rollers 2201b and 2203b.
This is to prevent the peripheral speed from changing due to the change in the deformation amount of 203a. In addition, setting the rubber hardness high in this way has the effect of suppressing the change in the outer diameter due to the change in the environmental temperature because the bonding force between the rubber molecules is strong, and in this respect also, the change in the peripheral speed can be suppressed. It can be prevented. The change in peripheral speed here appears as an error in the copy magnification. On the other hand, the driven roller 2203 of the second reading roller pair 2203
b is formed of a material having a low friction coefficient (for example, POM). This is so that even if the leading edge of the document conveyed by the first reading roller pair 2201 contacts the roller pair 2203 on the upstream side of the nip portion, the document is smoothly guided to the nip portion without stopping. .

The deterioration of the image reading accuracy due to the slack and dance of the document is caused by a large guide clearance on the slit glass 198, a large drop from the first reading roller pair 2201 to the slit glass 198, and an introduction guide plate 2204. When the plunge angle to the slit glass 198 is large, the scooping angle from the slit glass 198 to the guide plate 199 is large, the plunge angle from the guide plate 199 to the outlet guide plate 2205 is large, and the second reading roller pair 2203 is further included. It tends to occur when the plunge angle into is large. Therefore, it is necessary to have a shape and configuration that allows the original to smoothly pass through these sections. When the original is being conveyed only by the first reading roller pair 2201, the leading edge of the original is not smoothly conveyed due to the frictional resistance with the guide surface, and the conveying speed tends to be unstable. In order to eliminate this, it is preferable to slightly widen the guide clearance immediately after the press contact guide plate 2202 to reduce the conveyance resistance. In addition, the plunge angle from the slit glass 198 to each guide portion is set as small as possible, and
It is preferable to set the path between the reading roller pairs 2201 and 2033 to be the shortest.

(Concerning Conveyance Speed in Reading Section) As described above, after the leading edge of the original has been registered in the nip portion of the first reading roller pair 2201, the paper feed motor M1 and the conveyance motor M2 are turned on in synchronization. By doing so, the reading conveyance is started. At the time of this reading conveyance, the intermediate conveyance roller pair 2105
It is necessary to maintain the curved state of the document formed between the first reading roller pair 2201 and the first reading roller pair 2201. Therefore, it is necessary to set the relationship of the transport speed of the intermediate transport roller pair 2105 ≧ the transport speed of the first reading roller pair 2201. Further, according to the change of the copy magnification, the conveying speed of the reading roller pair 2201 and 2032 and the intermediate conveying roller pair 2
It is necessary to proportionally change the conveyance speed of 105 and satisfy the following expression (1).

[0062]       Vn ≧ Vm = V / M (1) M: Copy magnification V: Conveyance speed at the same magnification of the reading roller pair Vm: Conveying speed of the reading roller pair when the copy magnification is M Vn: Transport speed of the intermediate transport roller pair when the copy magnification is M

Satisfying the above expression (1) means that when a document is conveyed while being caught in the nip part of the reading roller pair 2201 and 2032 and the nip part of another roller pair, the document is conveyed between the nip parts. When there is no slack in the sheet and tension is applied, noise generated in other drive systems (clutch on / off, load fluctuations when the trailing edge of the original leaves the rollers 2103 and 2104, etc.) is read. Roller pair 22
This has an effect of preventing the constant speed conveyance of the original document from being impaired by influencing 01, 203. In addition, such a relationship of the conveyance speeds is as follows.
The same applies to the relationship with 201 and 2032.

(Relationship between Position and Velocity of Transporting Member) In the present document transporting apparatus 20, the position and transporting speed of each transporting member are set as follows in order to increase the amount of original reading per unit time. (See Figure 3). L _1: the paper feed roller 2103～ sensor SE6 between the distance L _2: sensor SE6~ intermediate transport rollers 2105 between the distance L _3: the distance between the intermediate transport rollers 2105～ first read rollers 2201 L _4: first read rollers 2201-reading position 190
Distance L ₅ : Reading position 190 to resin film 2304 Distance L ₆ : Resin film 2304 to first reading roller pair 22
Distance 01 between ₀₁ : pickup roller 2102, paper feed roller 210
3 Conveyance speed V ₀₂ : Intermediate conveyance roller pair 2105 registration conveyance speed V ₀₃ : Intermediate conveyance roller pair 2105 reading conveyance speed V ₀₄ : Reading roller pairs 2201 and 2203 conveyance speed V ₀₅ : Circulation reversal roller pair 2302 Conveyance speed during reading V ₀₆ : Conveyance speed during reversal of the circulation reversing roller pair 2302 V ₀₇ : Conveyance speed during reading of the paper ejection reversing roller pair 2402 V ₀₈ : Conveyance speed during reversal of the paper reversing roller pair 2402 V ₀₉ : Ejection Conveyance speed of the paper roller pair 2501 during reading V ₁₀ : Conveyance speed of the paper ejection roller pair 2501 during ejection V ₁₁ : Conveyance speed of the paper ejection roller pair 2501

At each of the above conveying speeds, the following equation (2),
The relationships (3) and (4) are set. V ₀₃ = V ₀₄ = V ₀₅ = V ₀₇ = V ₀₉ (2) V ₀₁ = V ₀₂ (3) V ₀₈ = V ₁₁ (4)

(In the single-sided original mode, except for mixed sizes and AMS mode), the first original is registered by the first reading roller pair 2201 whose rotation is stopped as described above. By the conveyance motor M2 being driven, the reading rollers 2201 and 2203 are conveyed at the speed V ₀₄ ,
The image is read. At this time, the sheet feeding motor M1 rotationally drives the intermediate conveying roller pair 2105 at a speed V ₀₃ , and before the leading edge of the original reaches the sheet discharging roller pair 2501, the sheet discharging motor M3 causes the sheet discharging roller pair 2501 to move at a speed V. It is rotationally driven at ₀₉ . When the second manuscript exists,
Immediately after the trailing edge of the first document passes the reading position 190, the transport motor M2 and the paper discharge motor M3 are turned off, and the first document stops at that position. When the trailing edge of the first document passes the width-size reference sensor SE6, the second document turns on the clutch CL1 and feeds the motor M1.
The paper is fed by changing the drive of V to the speed V ₀₁ .
Then, the first reading roller pair 220 that has stopped rotating
Registered at 1. By minimizing the time from the trailing edge of the first document passing the reading position 190 to the leading edge of the second document reaching the reading position 190,
The substantial reading time t per document is expressed by the following equation (5), where L _P is the length of the document. t = (L _P + L ₄ ) / V ₀₄ (5)

By setting the distance L ₄ to be as short as possible and setting it as close as possible to the following expression (7), t
= L _P / V ₀₄ as close as possible, and high reading efficiency can be achieved. {(L ₂ + L ₃ + L ₄ ) / V ₀₄ } ≦ {(L ₁ + L ₂ ) / V ₀₁ + L ₃ / V ₀₂ } ...... (7)

Further, when the copy magnification becomes large, the conveying speed of the reading roller pair 2201 and 2033 also becomes slow, and the original document being read and the original document being fed overlap each other, and the above expression (7) may not be satisfied. To do. However, the time (L ₂ + L ₃ + L ₄ ) / V when the trailing edge of the document being read reaches the reading position 190 after passing the width size reference sensor SE6
_{Since 04} is known, the speed V _{01 of the} pickup roller 2102 and the paper feed roller 2103, the pair of intermediate conveyance rollers 210
This can be solved by slowing the speed V ₀₂ of 5 so as to satisfy the expression (7) or by delaying the on-timing of the clutch CL1 by the difference between the left side and the right side of the expression (7).

Returning to the conveyance of the second original, the second original is conveyed to the reading position 190, and at the same time, the first original is ejected from the ejection roller pair 2501 onto the ejection tray 2502. Subsequently, the second original is also conveyed toward the paper ejection tray 2502. At this time, the conveyance speed of the pair of discharge rollers 2501 is set to the speed V ₀₉ because the distance between the first and second originals is the same as the distance L ₄ .

On the other hand, when the copy magnification decreases, the conveying speed of the reading roller pairs 2201 and 2203 increases. When the document is discharged by the pair of discharge rollers 2501 at this increased speed, the alignment state of the document on the discharge tray 2502 deteriorates. Therefore, a pair of discharge rollers 2501 is set for the document.
When the feeding force is applied only at
The conveyance speed of 501 is changed to V _10, which is slower than V ₀₉ .

(Double-sided original mode, but mixed size,
The first original is registered by the first reading roller pair 2201 as in the single-sided original mode, and then the first side reading operation is started. At this time, the switching claw 2301 is set to a position slightly rotated in the clockwise direction from the solid line position in FIG. Conveyor motor M
2 drives the reading roller pairs 2201 and 2033 at a speed V ₀₄ , and the sheet feeding motor M1 drives the intermediate conveyance roller pair 2105 at a speed V ₀₃ and the circulation reversing roller pair 2302 at a speed V ₀₅ . When the trailing edge of the document passes through the second reading roller pair 2203, the sheet feeding motor M1 drives the circulation reversing roller pair 2302 at a higher speed V ₀₆ , and the conveyance motor M2 is turned off.
When the trailing edge of the document passes through the resin film 2304, the driving of the paper feeding motor M1 is changed to the reverse rotation while maintaining the speed V ₀₆ . As a result, the document is turned upside down and the circulation conveyance path 23
10 is conveyed and registered by the first reading roller pair 2201 whose rotation is stopped. When the registration is completed, the paper feed motor M1 is turned off. It should be noted that a pair of circulation reversing rollers 2
The timing of changing 302 from the speed V ₀₅ to V ₀₆ may be the time when the trailing edge of the original has passed the reading position 190, and at the same time, the conveyance motor M2 may be changed so that the reading roller pair 2203 becomes the speed V ₀₆ .

The distance L ₅ + L ₆ is set to be as short as possible. This is to minimize the conveyance time when reading the double-sided image of one document. After that, in order to read the second side of the first document, the conveyance motor M2 drives the reading roller pairs 2201 and 2033 at a speed V ₀₄ , and the paper feeding motor M1 moves the circulation reversing roller pair 2302 at a speed V ₀₅ (however, , Reverse rotation direction). Further, the switching claw 2301 is returned to the solid line position in FIG. 2, and the switching claw 2401 is set to a position slightly rotated clockwise from the solid line position. Then, the paper discharge motor M3 is connected to the paper discharge reversing roller pair 240.
2 until the leading edge of the document reaches 2
02 is driven in reverse at a speed V ₀₇ . For the document whose second surface has been read, the conveyance motor M2 and the paper discharge motor M3 are turned off immediately after the trailing edge of the document passes the reading position 190.
By that time, when the trailing edge of the reversed document passes through the circulation reversing roller pair 2302, the paper feeding motor M1 is changed to drive in the forward rotation direction and the intermediate conveying roller pair 2105 at the speed V _02. .. Further, when the trailing edge of the document passes the registration sensor SE2, the clutch CL1 is turned on.
As a result, the feeding of the second original is started, and the loss time from the completion of the second side reading of the first original to the first side reading of the second original is shortened.

The feeding start timing of the second original is set at the time when the trailing edge of the original being read on the second side reaches the position of the distance L ₂ + L ₃ from the first reading roller pair 2201.
In other words, the time L _P − from the start of the second surface reading operation
If it is set at the time when (L ₂ + L ₃ ) / V ₀₄ has elapsed, the loss time can be further shortened and the same reading efficiency as in the single-sided original mode can be obtained.

Next, the feed motor M2 and the paper feed motor M1 are driven to read the first side of the second document, and at the same time, the paper discharge motor M3 moves the paper discharge reversing roller pair 2402 at the speed V _07.
Drive with. The paper discharge motor M3 changes the paper discharge reversal roller pair 2402 to a higher speed V ₀₈ when the trailing edge of the first document passes through the second reading roller pair 2203. further,
When the trailing edge of the document passes through the switching claw 2301, the switching claw 2301 is set at a position slightly rotated clockwise from the solid line position. When the trailing edge of the first original passes through the resin film 2403, the paper discharge motor M3 is switched to the normal rotation, and the original is conveyed to the paper discharge roller pair 2501 which is rotationally driven at the speed V ₁₁ . When the trailing edge of the original passes through the pair of paper output reversing rollers 2402, the paper output motor M3 reduces the conveying speed of the paper output roller pair 2501 to V ₁₀ , and the original is discharged onto the paper output tray 2502 at this speed V _10. To be done.

(Different Size Mixed Loading Mode) When originals of different sizes are included and the operator selects the mixed loading mode, the original feeding device 20 feeds the originals in a different operation.
The reason for this is that the sensor SE1 on the document tray 2101 is
1, SE12 detects the length of the document only for the longest size of the set document, and for the document of the short size, after the rear end of the document passes the width size reference sensor SE6,
In other words, it cannot be determined until the image reading is started, and the image processing in the copying machine main body 10 cannot cope with this. Therefore, when the APS mode is executed, after the paper feeding operation is started, the maximum document size determined by the combination of the outputs of the sensors SE6 and SE7 and the sensors SE11 and SE12 becomes the maximum document size per document in the image data memory of the copying machine body 10. Set the storage area. Since the distance L ₈ from the registration sensor SE2 to the reading roller pair 2201 is known in advance, the conveyance distance from the start of the conveyance of the document after registration by the reading roller pair 2201 to the passage of the trailing edge of the original from the registration sensor SE2. If (L ₉ ) is monitored, the length L _{P of the} document is found as L ₈ + L ₉ . When the true document size found based on the document length L _P and the outputs of the sensors SE6 and SE7 is smaller than the maximum size assumed as described above, the area corresponding to the true document size in the memory storage area. Only the laser optical unit 13 outputs it. However, in the APS mode, the second and subsequent originals are fed at the same timing as in the non-mixed loading mode.

On the other hand, when executing the AMS mode, if the setting direction of the original is different from the setting direction of the selected copy sheet, the image processing unit 12 must rotate the image by 90 ° on the horizontal plane. However, the document feeder 20 can detect the true document size only after the leading edge of the document reaches the reading unit 2200. Therefore, the copy magnification and the reading conveyance speed Vm by the reading roller pair 2201 and 2032.
Can't decide. Therefore, each document is initially passed through the reading unit 2200 without image reading, and the sensor S
Only the document size is detected by E6, SE7, and SE2. The original that has been passed through is passed through the reversing unit 2300 and again passes through the reading unit 2200. In the case of a one-sided original, the non-image surface faces the slit glass 198 at this time, and therefore, the document is passed through at high speed without reading the image. 3 again via the circulation inversion unit 2300
When facing the reading unit 2200 for the second time, the reading roller pair 22
01 and 2203 are set to the transport speed Vm corresponding to the copy magnification, and the image is read. After that, the document is discharged from the pair of discharge rollers 2501 to the tray 2502.

In the case of a double-sided original, when the original approaches the reading unit 2200 for the second time, the pair of reading rollers 2201 and 220
3 is set to the transport speed Vm corresponding to the copy magnification and the second
Read the surface image. Further, the reading unit 2200 is conveyed at the conveying speed Vm via the circulation reversing unit 2300 (third time), the first surface image is read, and the original is ejected from the ejection roller pair 2501 to the tray 2502. In this case, the reading order is reversed, but if reading is performed in the regular order (first surface to second surface), the circular inversion unit 2
This is because it is possible to prevent the reversing processing in the sheet ejection reversing unit 300 and the sheet reversing unit 2400 from increasing one time each and thus significantly reducing the reading efficiency. Then, if the page order is changed in the image data memory, no trouble will occur. Further, if the conveying speed is set to the maximum during the plain sheet passing without the image reading operation, the reduction in the reading efficiency can be suppressed as much as possible.

(Document Jam Processing) Main Document Feeder 20
In the above, there is a case where the document being conveyed is jammed, or due to a trouble in the copying machine main body 10, the driving of the apparatus 20 is suddenly stopped and the document is left in the conveyance path. In such a case, a mechanism for easily taking out the original without damaging the original is required. Also, no matter where the document is left on the transport path, you can check that position from the outside, and
It is necessary to open each part so that a hand can be inserted so that a manuscript can be easily grasped.

In the original document conveying device 20, the conveying path is constructed as follows. (1) Paper feed roller 2103
To the first reading roller pair 2201, (2) the first reading roller pair 2201 to the second reading roller pair 2203 (reading unit 2200), (3) the second reading roller pair 2
203 to circulation reversal roller pair 2302, (4) circulation reversal roller pair 2302 to first reading roller pair 2201
(Circulation conveyance path 2310), (5) second reading roller pair 2203 to paper discharge reversing roller pair 2402, (6)
From the sheet discharge reversing roller pair 2402 to the sheet discharge roller pair 2501, (7) from the second reading roller pair 2203 to the sheet discharge roller pair 2501, (8) from the manual feed tray 2601 to the first sheet
Up to reading roller pair 2201.

As shown in FIG. 4, the conveyance path (1) can be opened by rotating the paper feed unit cover 2119 around the support shaft 2120. At this time, the pair of intermediate conveying rollers 2
105 is separated. Further, the guide plate 2306 also rotates integrally with the cover 2119 around the support shaft 2120, so that a part of the circulation conveyance path 2310 is also opened.

The reading section 2200 is opened by lifting the document feeder 20 itself from the platen glass 111. At this time, the guide plates 2204, 2205 swing downward, and the driven rollers 2201b, 2201b,
2203b releases the pressure contact with the drive rollers 2201a and 2203a.

The document path of the document tray 210 is (3) above.
It is opened by opening 1 upward. At the same time, the pair of circulation reversing rollers 2302 are also released from pressure contact with each other. The transport paths (5) and (6) are opened by opening the document tray 2101 upward and then opening the guide plate 2406 upward.

As described above, by making each conveying path open, even if the original is jammed or left behind at any place, the original can be confirmed and one end thereof can be easily grasped by hand. it can. This makes it possible to easily pull out the document without damaging it.

(Suppression of Vibration of Conveyor Motor) If vibration occurs in the conveying motor M2 (stepping motor) during image reading, the vibration is transmitted to the pair of reading rollers 2201 and 2203 and the reading accuracy deteriorates. The stepping motor sets the drive current by adding an appropriate amount of margin to the maximum load torque in order to prevent step-out due to load fluctuations. However, when the load is low (especially during low-speed rotation), there is excess torque, which causes vibration and noise.

Therefore, in this embodiment, as shown in FIG. 13, the conveyance motor M2 is provided with a vibration detector 2150,
When the generated vibration is detected and it can be determined that the torque is excessive, the drive current value is reduced to adjust the torque to prevent vibration and noise. This also has the effect of saving power consumption by suppressing the supply of extra current.

As the vibration detector 2150, a piezoelectric element,
A pressure sensor, strain gauge, acceleration sensor, etc. can be used. The mounting position is a portion such as the support frame of the motor M2 that can directly detect vibration. In order to obtain a signal corresponding to the magnitude of the detected vibration, the filter circuits 2151 and 215
4, amplification circuits 2152 and 2155, integration circuit 2153,
It is converted into a voltage or a pulse by the F / V conversion circuit 2156 and input to the CPU 3000 as a vibration level and a vibration frequency. Since the generated vibration is different depending on the rotation speed of the motor M2, these circuits are used to detect the vibration frequency based on the number of pulses driving the motor M2 or to detect the vibration frequency from the signal of the detector 2150. use. In particular, the filter circuit 2154 removes unnecessary noise and extracts only the problematic frequency signal (several 100 Hz to several 10 kHz). F / V conversion circuit 2156
Converts the extracted frequency into voltage. The integrating circuit 2153 also converts the amplitude of vibration into a voltage.

As shown in Table 1 below, since the vibration level varies depending on the frequency band, when the detected frequency vibrates above a certain level, the drive current value becomes 0 within the range where the motor M2 does not step out. ．Decrease by 1A. The vibration levels have a relationship of Vf ₀ <Vf ₁ <Vf ₂ <Vf ₃ .

[0088]

[Table 1]

(Excitation Control of Transport Motor) Transport Motor M2
As the stepping motor, a stepping motor has a constant cycle in which excitation of each phase is switched during constant speed rotation, and therefore vibration and noise are generated due to resonance.
Vibration and noise due to resonance vary depending on the motor alone, the driving force transmission system, and the like. Therefore, in the present embodiment, the rotating 1
By changing the pulse width (excitation time) without changing the number of drive pulses per cycle (excitation switching times),
The transport speed is kept constant to suppress vibration and noise generated at the number of rotations near the resonance point.

Specifically, as shown in FIG. 9, when the switching cycle of the excitation is constant at t, the resonance (low speed range resonance) peculiar to the motor and the resonance (effect of the motor, circuit, load, inertia, etc.) ( Mid-range resonance) occurs. Document feeder 2
Since the number of revolutions at which vibration and noise due to resonance occur is known as 0, when driving at that number of revolutions, the number of drive pulses at a constant period t is kept constant without changing the overall rotation speed. , Excitation pattern (for example ,,) in which the width of the cycle t is changed for each pulse is used for driving. Vibration and noise due to resonance can be suppressed by such control.

For example, since resonance does not occur at high speed rotation, the motor M2 is driven with a constant cycle t in the excitation pattern. Resonance is generated at medium speed rotation, but it is very small. Therefore, driving is performed by an excitation pattern or a pattern in which the change of the cycle t is simplified. Furthermore, since a large resonance occurs at low speed rotation, the period t
Drive by gradually changing.

FIG. 10 is a time chart of the two-phase excitation method,
FIG. 11 shows a time chart of the 1-2 phase excitation method. Although the above description is based on the 1-2 phase excitation method, W1
The same control can be performed by the -2 phase excitation method or the microstep excitation method.

Furthermore, it is possible to prevent vibration and noise due to resonance by using controls other than the above. For example, the excitation mode is changed near the resonance point (from 2 phase to 1-2 phase or W1.
-2 phase). As a result, it is possible to drive by changing the pulse rate away from the resonance point without changing the transport speed. Alternatively, when it is necessary to drive near the resonance point depending on the copy magnification, it is driven at a speed distant from the resonance point (for example, a conveyance speed at equal magnification, a conveyance speed at a magnification of 2),
It is also possible to correct to a desired transport speed by electrical scaling processing, that is, to correct read image data to a desired magnification in post processing.

(Control Circuit) FIG. 12 shows a schematic configuration of a control circuit of the document feeder 20. This control circuit is the CPU 30
00, the following signals from sensors and the like are input, and control signals are output to motors, solenoids, and the like.

SE1: Empty sensor. It is detected whether or not a document is set on the tray 2101. Document detection when off. SE2: Registration sensor. First reading roller pair 2201
The document is detected immediately before. Document detection when on. Further, it is also used for detecting the length of the document. SE3: Paper ejection sensor. The original is detected in the paper output switchback path. Document detection when on. SE4: Circulation inversion sensor. A document is detected in the circulation switchback path. Document detection when on. SE5: Paper ejection reversal sensor. The original is detected in the paper output switchback path. Document detection when on. SE6: Width size reference sensor. Detects the width size of the fed document. Document detection when on. SE7: Width size sensor. Detects the width size of the fed document. Document detection when on.

SE11: Length size sensor. Tray 21
The length of the original set on 01 is detected. Document detection when on. SE12: Length size sensor. The length of the document set on the tray 2101 is detected. Document detection when on. SE14: Read sensor. The reading unit 2200 detects the document. Document detection when on. SE15: Upper limit sensor. It is detected whether or not the document on the tray 2101 has risen to the paper feeding position. When it is turned on, the completion of climb is detected. SE16: Lower limit sensor. It is detected whether the lift-up plate 2107 is set at the lower limit (home position). Detects home position when turned on. Note that it is not shown in FIG.

M1: Paper feed motor. Rollers 2102, 21
03, the roller pairs 2105 and 2302 are driven. The rotation direction at the time of feeding and reading is CW, and the rotation direction at the time of circulation switchback is CCW. M2: Transport motor. The roller pairs 2201 and 2032 are driven. The rotation direction is CW. M3: Paper discharge motor. The roller pairs 2402 and 2501 are driven. The rotation direction at the time of paper discharge switchback is CW, and the rotation direction at the time of paper discharge is CCW. M4: Lift-up motor. The lift-up plate 2107 is moved up and down. The rotation direction when descending is CW, and the rotation direction when ascending is CCW. Note that it is not shown in FIG.

SL1: Circulation inversion solenoid. Switching claw 2
Drive 301. When turned on, the switching claw 2301 is rotated clockwise from the solid line position in FIG. It is not shown in FIG. SL2: Paper discharge reversal solenoid. The switching claw 2401 is driven. When turned on, the switching claw 2401 is rotated clockwise from the solid line position in FIG. It is not shown in FIG. CL1: Paper feed clutch. The drive force to the paper feed roller 2103 is turned on / off. The drive force is transmitted when it is on. SO: Transmission signal to the copying machine main body SI: Reception signal from the copying machine main body 10

(Control parameters) Next, the CPU 300
Various control parameters used in the control of the document feeder 20 by 0 will be described.

Transport mode: Set based on the operation mode selected by the operator, and the data is transmitted from the copying machine main body 10 to the CPU 3000. It can be divided into the following types. "01": Single-sided original, high-speed, APS "02": Single-sided original, high-speed, AMS "03": Single-sided original, high-speed, manual "04": Single-sided original, mixed, APS "05": Single-sided original, mixed, AMS “06”: Double-sided original, high speed, APS “07”: Double-sided original, high speed, AMS “08”: Double-sided original, high speed, manual “09”: Double-sided original, mixed, APS “10”: Double-sided original, mixed, AMS

TMRFA: timer value. The document is a sensor SE
Time from 6 to reach the intermediate conveying roller pair 2105. TMRFB: timer value. Time to form a curved portion when registering the leading edge of a document TMRD: Timer value. The timing for determining whether the sensor SE7 is on or off when the width size is detected is determined. Paper feed counter: Counts the number of completed paper feeds.

CNTA: A counter for counting the number of drive pulses of the carry motor M2 from the on edge of the sensor SE14. PLSA: Number of drive pulses of the conveyance motor M2 until the leading edge of the document reaches the reading position 190. PLSB: Transport motor M2 until image reading is completed
Number of drive pulses of. CNTC: Feed motor M from the off edge of sensor SE6
A counter that counts the number of drive pulses of 1. PLSC: Paper feed motor M until the next original can be fed
Number of drive pulses of 1. CNTD: Transfer motor M from the off edge of sensor SE2
A counter that counts the number of drive pulses of 2. PLSD: Transport motor M from the off edge of the sensor SE2 until the trailing edge of the original passes through the second reading roller pair 2203.
2 drive pulses.

CNTE: A counter for counting the number of drive pulses of the sheet feeding motor M1 at the time of reversing the circulation. PLSE: When the circulation is reversed, the trailing edge of the document is a pair of circulation reversal rollers 2.
The number of drive pulses of the sheet feeding motor M1 before passing through 302 CNTG: Feed motor M from the on edge of sensor SE4
A counter that counts the number of drive pulses of 1. PLSG: The number of drive pulses of the sheet feeding motor M1 from the ON edge of the sensor SE4 to the switchback of the document. MPLSCNT: A counter that counts the number of drive pulses after the carry motor M2 is turned on. SIZCNT: MPL when the sensor SE2 is turned off
The value of SCNT.

CNTH: A counter that counts the number of drive pulses of the paper discharge motor M3 from the time when the trailing edge of the original reaches the reading position 190 until the time of deceleration. PLSH: Number of drive pulses until the paper discharge motor M3 is decelerated. PLSI: Number of drive pulses of the discharge motor M3 until the trailing edge of the original passes through the discharge roller pair 2501. CNTI: Paper discharge motor M from the on edge of sensor SE5
A counter that counts the number of driving pulses of 3. PLSJ: Number of drive pulses of the discharge motor M3 from the ON edge of the sensor SE5 to the start of switchback of the document. CNTJ: Paper ejection motor M from the off edge of sensor SE5
A counter that counts the number of driving pulses of 3. PLSK: discharge motor M from the off edge of sensor SE5
Number of drive pulses until 3 is decelerated. PLSL: Number of drive pulses of the discharge motor M3 from the off edge of the sensor SE5 until the trailing edge of the document passes through the discharge roller pair 2501.

The parameters used for drive control of the carry motor M2 are as follows. Length A: Document length detected by the sensors SE11 and SE12 Length B: Document length detected by the sensor SE2. Vf: A value obtained by converting the vibration of the motor M2 into a voltage. Ih: Drive current value during high-speed conveyance by the motor M2 Im: Drive current value during medium speed conveyance by the motor M2. Il: Drive current value during low speed conveyance by the motor M2. Ih _min , Im _min , Il _min : Lower limit value of the drive current of the motor M2. f _M : Vibration frequency of the motor M2. Vf ₁ , Vf ₂ , Vf ₃ : threshold values of the vibration level of the motor M2.

Further, various flags will be described. Read start flag: Instruct to start the operation of the document feeder 20. Based on the operation start signal transmitted from the copying machine main body 10 to the CPU 3000. In-operation flag: Indicates that the document feeder 20 is in operation. Paper feed weight flag: Instruct to prohibit paper feed operation. Vm fixed flag: Instructing prohibition of changing the transport speed during a series of operations.

Reading flag: Indicates that the original image is being read. Scan prohibition flag: Instructs to prohibit reading even when the document is passing the reading unit 2200. Second side flag: Indicates that the document passes the reading unit 2200 for the second time. Third surface flag: Indicates that the document passes through the reading unit 2200 for the third time. Paper discharge flag: Indicates that the document is being discharged to the paper discharge tray 2502. Switchback flag: Indicates that the document is being switched back.

(Control Procedure) The control procedure of the document feeder 20 by the CPU 3000 will be described below with reference to the attached flowchart.

FIG. 14 shows the main routine of the CPU 3000. When the power is turned on and the program starts, first, in step S1, each device and various parameters are returned to the initial state, and in step S2, an internal timer is started. The internal timer determines the time required for one routine, and is set to a predetermined value in step S1. The timer appearing in the following subroutine is counted using the length of this one routine.

Next, the subroutines of steps S3 to S11 are sequentially called to execute the necessary processing. The subroutine of steps S3 to S11 will be described in detail below. If it is determined in step S12 that the internal timer has ended,
Return to step S2.

FIG. 15 and FIG. 16 show a tray raising / lowering subroutine executed in step S3. First, step S
21 determines whether the empty sensor SE1 is on or off,
If it is on (if no document is set on the tray 2101,) it is determined in step S22 whether the lower limit sensor SE16 is on or off. If the sensor SE16 is off (if the lift-up plate 2107 is not at the home position), the lift-up motor M4 is CWed in step S23.
Set to and turn on. With this, the lift-up plate 2107
Goes down. If the sensor SE16 is on (if the lift-up plate 2107 has descended to the home position), the motor M4 is turned off in step S24.

Next, when it is confirmed in step S25 that the reading start flag is set to "1", the operating flag is set to "1" in step S26, the clutch CL1 is turned on, and the paper feed weight flag is set. Is set to "1" and the transport mode is set. The transport mode is "01" to "10" as described above depending on the type of document and the copy mode.
It is classified into.

Next, when it is confirmed in step S27 that the operating flag is set to "1", the lift-up motor M4 is set to CCW and turned on in step S28. Further, in step S29, the upper limit sensor SE15
Is turned on and off, and if it is on (when the upper surface of the original is in pressure contact with the pickup roller 2102), it is determined in step S30 whether the paper feed weight flag is set to "1", and " If it is set to "1", the flag is reset to "0" in step S31. Further, in step S32, the lift-up motor M4 is turned off and the paper feeding state is set to 1.

Next, in steps S33 and S34, the lengths of the originals on the tray 2101 are detected by turning on and off the length size sensors SE11 and SE12. Sensor SE1
If 1, SE12 is on, length A in step S35
Is stored as “1”. If the sensor SE11 is on and the sensor SE12 is off, the length A is stored as "2" in step S36. If the sensor SE11 is off, the length A is stored as "3" in step S37.

17 and 18 show the paper feeding subroutine executed in step S4. First, after confirming that the paper feed weight flag is reset to "0" in step S41, the count value of the paper feed state is checked in step S42, and the following processing is executed according to the count value. If the paper feeding state is 0, step S4
After confirming that the empty sensor SE1 is on (there is a document) in step 3, the sheet feeding state is set to 1 in step S44, and the clutch CL1 is turned on.

If the paper feeding state is 1, step S4
5, the speed Vn is set to REF (paper feed speed), and the paper feed motor M
1 is set to CW and turned on, and the paper feeding state is set to 2. As a result, the uppermost one document is fed. When the paper feed state is 2, when the on-edge of the width size reference sensor SE6 is confirmed in step S46,
At 47, the timer TMRFA is started, the size detection state is set to 1, and the paper feeding state is set to 3.

If the paper feeding state is 3, step S4
After confirming the end of timer TMRFA in step 8, step S
At 49, the clutch CL1 is turned off, the timer TMRFA is reset, and the paper feeding state is set to 4. If the paper feeding state is 4, the registration sensor SE is detected in step S50.
When the on-edge of 2 is confirmed, the timer TMRFB is started in step S51 and the paper feeding state is set to 5.

When the paper feeding state is 5, step S5
After confirming the end of timer TMRFB in step 2, step S
The timer TMRFB is reset at 53, and the paper feeding motor M1
Is turned off, the paper feed weight flag is set to "1", the paper feed counter is incremented, and the paper feed state is reset to zero. As a result, the leading edge of the document is registered at the nip portion of the first reading roller pair 2201 and is curved in an appropriate amount.

FIGS. 19, 20, and 21 show the size detection 1 subroutine executed in step S5. Here, the count value of the size detection state is checked in step S61, and the following processing is executed according to the count value. When the size detection state is 1 (step S
47), the timer TMRD is started in step S62, and the size detection state is set to 2.

When the size detection state is 2, when the end of the timer TMRD is confirmed in step S63, it is determined in step S64 whether the width size sensor SE7 is on or off. If the sensor SE7 is on, the timer TMRD is reset in step S65 and the width is stored as "1",
Further, the size detection state is set to 4. Sensor S
If E7 is off, timer TMRD is determined in step S66
Reset and start, and set the size detection state to 3
Set to.

When the size detection state is 3, when the end of the timer TMRD is confirmed in step S67, it is determined in step S68 whether the sensor SE7 is on or off. If the sensor SE7 is on, the timer TM is detected in step S69.
RD is reset, the width is stored as "2", and the size detection state is set to 5. If the sensor SE7 is off, the timer TMRD is reset and the size detection state is set to 6 in step S70.

When the size detection state is 4, the stored value of the length A is calculated in steps S71 and S73 (steps S35 to S35).
Refer to S37). If the length A is "1", the document size is stored as "01" in step S72.
If the length A is "2", the document size is stored as "02" in step S74. When the length A is "3", the document size is stored as "03" in step S75.
After that, the size detection state is reset to 0 in step S76.

When the size detection state is 5, the stored value of the length A is calculated in steps S77 and S79 (steps S35 to S35).
Refer to S37). If the length A is "1", the document size is stored as "04" in step S78.
If the length A is "2", the document size is stored as "05" in step S80. When the length A is "3", the document size is stored as "06" in step S81. After that, the size detection state is reset to 0 in step S82.

When the size detection state is 6, the stored value of the length A in steps S83 and S85 (steps S35 to S35).
Refer to S37). If the length A is "1", the document size is stored as "07" in step S84.
If the length A is "2", the document size is stored as "08" in step S86. If the length A is "3", the document size is stored as "09" in step S87.
After that, the size detection state is reset to 0 in step S88. In the description of FIGS. 6 to 8 described above, the width sizes are classified into 6 types, but here, the width size is described as 3 types (two levers).

22 to 26 show a speed setting subroutine executed in step S6. Here, first, when it is confirmed that the paper feed counter is set to 1 in step S91, the transport mode is checked in step S92, and the following processing is executed according to the value. When the transport mode is "01" or "03", after confirming that the Vm fixed flag is reset to "0" in step S93, the speed Vm is set to V / m in step S94 and fixed to Vm. The flag is set to "1" (V: transport speed at equal magnification, m: copy magnification).

When the carrying mode is "02", after confirming that the Vm fixed flag is reset to "0" in step S95, the copy magnification m is set to "sheet length / length A" in step S96. And set the speed Vm to V / m
And set the Vm fixed flag to "1". When the transport mode is "04", after confirming that the reading flag is reset to "0" in step S97, the speed Vm is set to V / m in step S98, and V is set to V / m.
The m fixed flag is reset to "0".

When the transport mode is "05", it is confirmed in step S99 that the reading flag is reset to "0", and it is determined in step S100 whether the third surface flag is "0". To do. If the third surface flag is reset to "0", the speed Vm is set to the maximum speed Vmax, the scan inhibition flag is set to "1", and the Vm fixed flag is reset to "0" in step S101. Further, in step S102, it is determined whether or not the second surface flag is "0", and if it is reset to "0", step S
At 103, the second surface flag is set to "1" and the solenoid SL1 is turned on. If the second surface flag is set to "1", the second surface flag is reset to "0" and the third surface flag is set to "1" in step S104.

On the other hand, if it is determined in step S100 that the third surface flag is set to "1", the copy magnification m is set to "sheet length / length B" and the speed Vm is set to V in step S105. / M and reset the Vm fixed flag to "0". Further, the third surface flag is reset to "0", the scan prohibition flag is reset to "0", and the solenoid SL1 is turned off.

When the carrying mode is "06" or "08", it is confirmed in step S106 that the reading flag is reset to "0", and in step S107, whether or not the Vm fixed flag is "0". To determine. If the flag is reset to "0", the speed Vm is set to V / m and the Vm fixed flag is set to "1" in step S108. Next, in step S109, it is determined whether or not the second surface flag is "0", and if it is reset to "0", the second surface flag is set to "1" in step S110 and the solenoid SL1 is turned on. To do. If the second side flag is set to "1", the second side flag is set in step S111.
The surface flag is reset to "0", the solenoid LS1 is turned off, and the solenoid SL2 is turned on.

When the transport mode is "07", it is confirmed in step S112 that the reading flag is reset to "0", and then it is determined in step S113 whether the Vm fixed flag is "0". . If the flag is reset to "0", the copy magnification m is set to "sheet length / length A" and the speed Vm is V / m in step S114.
And set the Vm fixed flag to "1". Next, in step S115, it is determined whether or not the second surface flag is "0", and if it is reset to "0", step S1
The second surface flag is set to "1" at 16, and the solenoid S
Turn on L1. If the second surface flag is set to "1", the second surface flag is reset to "0" in step S117, the solenoid SL1 is turned off, and the solenoid SL
Turn on 2.

When the transport mode is "09", it is confirmed in step S118 that the reading flag is reset to "0", and then the speed Vm is set to V in step S119.
/ M and reset the Vm fixed flag to "0". Next, in step S120, it is determined whether or not the second surface flag is "0", and if it is reset to "0", the second surface flag is set to "1" in step S121 and the solenoid SL1 is turned on. To do. If the second surface flag is set to "1", the second surface flag is reset to "0" in step S122, the solenoid SL1 is turned off, and the solenoid SL2 is turned on.

When the transport mode is "10", it is confirmed in step S123 that the reading flag is reset to "0", and then it is determined in step S124 whether the second surface flag is "0". To do. If the flag is reset to "0", it is determined in step S125 whether the third surface flag is "1". If the third surface flag is set to "1" and the second surface flag is set to "1", the copy magnification m is set to "sheet length / length B" in step S126. , Vm is set to V / m, the Vm fixed flag is reset to “0”, and the scan prohibition flag is reset to “0”. Next, step S
At 128, it is determined whether the third surface flag is "1", and "1" is determined.
If so, the third surface flag is reset to "0" in step S129, and the solenoid SL1 is turned off. If it is reset to "0", step S130
Resets the second surface flag to "0" and sets the third surface flag to "1". On the other hand, when it is determined in step S125 that the third surface flag is reset to "0", the speed Vm is set to the maximum speed Vmax, the scan prohibit flag is set to "1", and Vm is set in step S127.
Reset the fixed flag to "0". Further, the second surface flag is set to "1" and the solenoid SL1 is turned on.

27 and 28 show the excitation pattern setting subroutine executed in step S7. In addition, in the following description, "excitation patterns" means those shown in FIG. Here, first, in step S141, the transport mode is checked, and the following processing is executed according to the value. Transport mode is "01", "02", "03" or "04"
If, then the speed Vm is checked in step S142,
If it is high speed, the excitation pattern is set in step S143, if it is medium speed, the excitation pattern is set in step S144, and if it is low speed, the excitation pattern is set in step S145.

When the transport mode is "05", it is determined in step S146 whether the third surface flag is "1",
If it is set to "1", the speed Vm is checked in step S147. If it is high speed, the excitation pattern is set in step S148, and if it is medium speed, step S1
The excitation pattern is set at 49, and if the speed is low, the excitation pattern is set at step S150. On the other hand, if it is determined in step S146 that the third surface flag is reset to "0", the excitation pattern is set in step S151.

Transport modes are "06", "07", "0"
If it is "8" or "09", it is determined in step S152 whether the second surface flag is "1". If it is set to "1", steps S147 to S150 are processed.
If it is reset to "0", the above step S142.
~ S145 is processed. When the transport mode is "10", it is determined in step S153 whether or not the third surface flag is "1", and if it is set to "1", the above-mentioned step S153 is performed.
147 to S150 are processed. If it is reset to "0", it is determined in step S154 whether or not the second surface flag is "1". If it is set to "1", the above steps S147 to S150 are processed to "0". If it is reset to step S151, the step S151 is processed.

29 to 31 show a read subroutine executed in step S8. Here, first, after confirming that the paper feed weight flag is set to "1" in step S161, the transport mode is checked in step S162, and the following processing is executed according to the value. When the transport mode is "01", "02", "03" or "04", the reading state A is checked in step S163, and the following processing is executed according to the count value.

When the reading state A is 0, the carry motor M2 is turned on in step S164, the paper feed motor M1 is set to CW and turned on, and the clutch CL1 is turned off. Further, the discharge motor M3 is set to CCW and turned on, the discharge flag is set to "1", and the reading state A is set to 1. The document is now the first reading roller pair 220.
Transport is started from 1.

When the reading state A is 1, when the on-edge of the reading sensor SE14 is confirmed in step S165 (when the leading edge of the document reaches the sensor SE14), the counter CNTA of the carry motor M2 is started in step S166, and the reading is performed. Set state A to 2. When the read state A is 2, CN in step S167
It is determined whether or not the count value of TA matches with PLSA. If YES (when the leading edge of the document reaches the reading position 190), the reading start timing signal VD is generated in step S168, and the reading flag is set to "1". , And read state A to 3.

When the reading state A is 3, when the off edge of the width size reference sensor SE6 is confirmed in step S169 (when the trailing edge of the document passes the sensor SE6).
In step S170, the counter CNTC of the paper feeding motor M1
To set read state A to 4.
If the read state A is 4, C is read in step S171.
It is determined whether or not the count value of the NTC matches the PLSC, and if YES (if the next original can be fed),
In step S172, the paper feed weight flag is reset to "0", the clutch CL1 is turned on, the counter CNTC is reset, and the reading state A is set to 5. By this, the feeding of the next document is started.

If the reading state A is 5, it is determined in step S173 whether or not the count value of CNTA matches PLSB. If YES (when the trailing edge of the document passes the reading position 190), step S174. Then, the carry motor M2 is turned off, the reading flag is reset to "0", and the counter CNTA is reset. Further, the paper feed counter is decremented, the paper discharge motor M3 is turned off, and the reading state A is reset to 0.

Thereafter, if it is determined in step S175 that the transport mode is "04", size detection 2 is processed in step S176. When different sizes are mixed, the length of the document is detected by using the registration sensor SE2. When the transport mode is "05", the third step is performed in step S181.
It is determined whether the surface flag is "1" and whether the second surface flag is "1" in step S182. Third surface flag is "1"
If set to, steps S231 to S2 described later
Process 44. If the second surface flag is set to "1", steps S211 to S221 described later are processed,
If it is reset to "0" (the first surface flag is "1"
Is set to), step S191 to be described later
Process S200.

Transport modes are "06", "07", "0"
If it is 8 "or" 09 ", it is determined in step S183 whether or not the second surface flag is" 1 ". If it is set to" 1 ", steps S271 to S284 described later are processed,
If it is reset to "0" (the first surface flag is "1"
Is set to), step S251 to be described later
Process S267.

If the carrying mode is "10", it is determined in step S184 whether the third surface flag is "1", step S1.
At 85, it is determined whether the second surface flag is "1". If the third surface flag is set to "1", steps S231 to S244 described later are processed. If the second surface flag is set to "1", step S291 described later.
~ S307 is processed, and if it is reset to "0" (if the first surface flag is set to "1"), steps S191 to S200 described later are processed.

In FIG. 32, the transport mode is "05" or "1".
0 "indicates the processing when the document passes through the reading unit 2200 for the first time. First, in step S191, the inversion state A is checked and the following processing is executed according to the count value. When step S
At 192, the carry motor M2 is turned on and the paper feed motor M1 is turned on.
It is set to W and turned on, and the solenoid SL1 is turned on. Further, the discharge motor M3 is set to CW and turned on, and the reverse state A is set to 1. As a result, the document starts to be conveyed from the first reading roller pair 2201.

When the inversion state A is 1, step S
When the off edge of the registration sensor SE2 is confirmed in 193 (when the trailing edge of the document passes the sensor SE2), the counter CNTD of the carry motor M2 is started and the reverse state A is set to 2 in step S194. When the inversion state A is 2, it is determined in step S195 whether or not the count value of CNTD matches PLSD, and YES.
If so (when the trailing edge of the document passes through the second reading roller 2203), the conveyance motor M2 is turned off in step S196,
Reset the counter CNTD. Further, the switchback flag is set to “1” and the inversion state A is set to 3
Set to. The document is then switched back in step S199, and the size is detected in step S200.

When the inversion state A is 3, step S
When it is confirmed in 197 that the switch-back flag is reset to "0", the inversion state A is reset to 0 in step S198.

FIG. 33 shows the processing when the document is passed through the reading section 2200 for the second time when the transport mode is "05". First, in step S211, the inversion state B is checked, and the following processing is executed according to the count value.
When the reversal state B is 0, the carry motor M2 is turned on in step S212, the paper feed motor M1 is set to CCW and turned on, and the solenoid SL1 is turned on. Further, the counter CNTE of the sheet feeding motor M1 is started and the reverse state B is set to 1. With this, the circulation conveyance path 23
The document in 10 is conveyed from the first reading roller pair 2201.

If the inversion state B is 1, step S
At 213, it is determined whether or not the count value of CNTE matches PLSE. If YES (when the trailing edge of the document passes through the reversing roller pair 2302), the paper feed motor M1 is turned off at step S214, and the counter CNTE is set. Reset. Further, the paper feed motor M1 is set to CW and turned on, and the reverse state B is set to 2.

When the inversion state B is 2, step S
When the off edge of the registration sensor SE2 is confirmed in 215 (when the trailing edge of the document passes the sensor SE2), the counter CNTD of the carry motor M2 is started and the reverse state B is set to 3 in step S216. When the inversion state B is 3, it is determined in step S217 whether the count value of CNTD matches PLSD, and YES.
If so (when the trailing edge of the document passes through the second reading roller 2203), the conveyance motor M2 is turned off in step S218,
Reset the counter CNTD. Furthermore, to set the switchback flag to "1", and sets the velocity V _M1 of the feed motor M1 to the maximum speed Vmax, set the inversion state B to 4. The document is then switched back in step S221.

When the inversion state B is 4, step S
When it is confirmed in 219 that the switchback flag is reset to "0", the inversion state B is reset to 0 in step S220.

34 and 35 show the processing when the document passes through the reading section 2200 for the third time in the transport mode "05" or "10". First, in step S231, the read state B is checked, and the following processing is executed according to the count value. When the reading state B is 0, the carry motor M2 is turned on in step S232, the paper feed motor M1 is set to CCW and turned on, and the solenoid SL1 is turned off. Further, the paper discharge motor M3 is set to CCW and turned on, and the counter CNTE of the paper feed motor M1 is started. Further, the paper discharge flag is set to "1" and the reading state B is set to 1. With this, the circulation conveyance path 2
The document in 310 is conveyed from the first reading roller pair 2201.

When the reading state B is 1, when the on-edge of the reading sensor SE14 is confirmed in step S233 (when the leading edge of the document reaches the sensor SE14), the counter CNTA of the carry motor M2 is started in step S234, and reading is performed. Set state B to 2. When the read state B is 2, CN in step S235
It is determined whether or not the count value of TA matches PLSA, and if YES (when the leading edge of the document reaches the reading position 190), the reading start timing signal VD is generated in step S236, and the reading flag is set to "1". , And read state B to 3.

When the reading state B is 3, it is determined in step S237 whether or not the count value of CNTE matches PLSE, and if YES (when the trailing edge of the document passes through the circulation reversing roller pair 2302), In step S238, the paper feed motor M1 is turned off, the counter CNTE is reset, and the reading state B is set to 4. When the reading state B is 4, when the off edge of the registration sensor SE2 is confirmed in step S239 (when the trailing edge of the document passes the sensor SE2), the paper feed weight flag is reset to "0" in step S240, and the paper feed weight flag is reset. The paper counter is decremented, the clutch CL1 is turned on, and the reading state B
Set to 5. This makes it possible to feed the next document.

When the reading state B is 5, it is determined in step S241 whether or not the count value of CNTA matches PLSB. If YES (when the trailing edge of the document passes the reading position 190), step S242. Then, the carry motor M2 is turned off, the reading flag is reset to "0", and the counter CNTA is reset. Further, the paper discharge motor M3 is turned off and the reading state B is set to 6.

When the reading state B is 6, it is confirmed in step S243 that the paper feed weight flag is set to "1", and then the reading state B is reset to 0 in step S244.

36 and 37, the carrying mode is "06",
"07", "08", or "09" indicates the processing when the document first passes through the reading unit 2200. First, in step S251, the read state C is checked, and the following processing is executed according to the count value. When the reading state C is 0, the conveyance motor M2 is determined in step S252.
Is turned on, the sheet feeding motor M1 is set to CW and turned on, and the solenoid SL1 is turned on. Further, the discharge motor M3 is set to CCW and turned on, and the reading state C is set to 1. The document is now the first reading roller pair 2201.
Transport is started from. When the reading state C is 1, when the on-edge of the reading sensor SE14 is confirmed in step S253 (when the leading edge of the document reaches the sensor SE14), the counter CNTA of the conveyance motor M2 is started in step S254, and the reading state C is set. Set to 2.

If the reading state C is 2, it is determined in step S255 whether or not the count value of CNTA matches PLSA. If YES (when the leading edge of the document reaches the reading position 190), in step S256. The read start timing signal VD is generated, the reading flag is set to "1", and the read state C is set to 3. If the read state C is 3, step S257
If the off-edge of the registration sensor SE2 is confirmed in (when the trailing edge of the document passes the sensor SE2), step S
At 258, the counter CNTD of the carry motor M2 is started, and the read state C is set to 4.

If the reading state C is 4, it is determined in step S259 whether or not the count value of CNTA matches PLSB. If YES (when the trailing edge of the document passes the reading position 190), step S260. Resets the reading flag to "0", resets the counter CNTA, and sets the reading state C to 5. If the read state C is 5, it is determined in step S261 whether the count value of CNTD matches PLSD, and YE
If S (when the trailing edge of the document passes through the second reading roller 2203), the conveyance motor M2 is turned off and the counter CNTD is reset in step S262. Further, the switchback flag is set to "1", and the paper feeding motor M1 is set.
The speed V _M1 is set to the maximum speed Vmax, and the read state C is set to 6. The manuscript is then step S265.
If it is determined that the transport mode is switched back in step S266 and the transport mode is “09” in step S266, the step S26 is performed.
The size is detected at 7.

When the read state C is 6, when it is confirmed in step S263 that the in-switchback flag is reset to "0", the read state C is reset to 0 in step S264.

38 and 39, the transport mode is "06",
"07", "08", or "09" indicates processing when the document passes through the reading unit 2200 for the second time. First, in step S271, the read state D is checked, and the following processing is executed according to the count value. When the reading state D is 0, the carry motor M is read in step S272.
2 is turned on, the paper feed motor M1 is set to CCW and turned on, the solenoid SL1 is turned off, and the solenoid SL2 is turned on. Further, the paper discharge motor M3 is set to CW and turned on, and the counter CNTE of the paper feed motor M1 is started. Further, the paper discharge flag is set to "1" and the reading state D is set to 1. With this, the circulation conveyance path 23
The document 10 is started to be conveyed from the first reading roller pair 2201.

When the reading state D is 1, when the on-edge of the reading sensor SE14 is confirmed in step S273 (when the leading edge of the document reaches the sensor SE14), the counter CNTA of the carry motor M2 is started in step S274, and the reading is performed. Set state D to 2. When the read state D is 2, CN in step S275
It is determined whether or not the count value of TA matches PLSA, and if YES (when the leading edge of the document reaches the reading position 190), the reading start timing signal VD is generated in step S276 and the reading flag is set to "1". , And read state D to 3.

If the reading state D is 3, it is determined in step S277 whether or not the count value of CNTE matches PLSE, and if YES (when the trailing edge of the document leaves the circulation reversing roller pair 2302), In step S278, the paper feed motor M1 is turned off, the counter CNTE is reset, and the reading state D is set to 4. When the reading state D is 4, when the off edge of the registration sensor SE2 is confirmed in step S279 (when the trailing edge of the document passes the sensor SE2), the paper feed weight flag is reset to "0" in step S280, and the paper feeding weight flag is reset. The paper counter is decremented, the clutch CL1 is turned on, and the reading state D
Set to 5. This makes it possible to feed the next document.

When the reading state D is 5, it is determined in step S281 whether or not the count value of CNTA matches PLSB. If YES (when the trailing edge of the document passes the reading position 190), step S282. Then, the transport motor M2 and the paper discharge motor M3 are turned off, and the clutch CL1 is turned on. Further, the reading flag is reset to "0", the counter CNTA is reset, and the reading state D
Set to 6.

When the reading state D is 6, it is confirmed in step S283 that the paper feed weight flag is set to "1", and then the reading state D is reset in step S284.

40 and 41, the carrying mode is "10".
The process when the document passes through the reading unit 2200 for the second time will be described. First, in step S291, the read state E is checked, and the following processing is executed according to the count value. When the read state E is 0, step S
At 292, the carry motor M2 is turned on, and the paper feed motor M1 is turned on.
CW is set and turned on, and solenoid SL1 is turned on.
Further, the counter CNTE of the sheet feeding motor M1 is started and the reading state E is set to 1. With this,
The document on the circulating conveyance path 2310 is the first reading roller pair 2
The conveyance is started from 201.

When the reading state E is 1, when the on-edge of the reading sensor SE14 is confirmed in step S293 (when the leading edge of the document reaches the sensor SE14), the counter CNTA of the carry motor M2 is started in step S294, and reading is performed. Set state E to 2. When the read state E is 2, CN in step S295
It is determined whether or not the count value of TA matches PLSA, and if YES (when the leading edge of the document reaches the reading position 190), the reading start timing signal VD is generated in step S296, and the reading flag is set to "1". , And read state E to 3.

If the reading state E is 3, it is determined in step S297 whether or not the count value of CNTE matches PLSE, and if YES (when the trailing edge of the document passes through the circulation reversing roller pair 2302). In step S298, the paper feed motor M1 is turned off and the counter CNTE is reset. At the same time, the paper feed motor M1 is CWed in step S299.
Set to 0 to set read state E to 4.

When the reading state E is 4, when the off edge of the registration sensor SE2 is confirmed in step S300 (when the trailing edge of the document passes the sensor SE2), the counter CNTD of the carry motor M2 is started in step S301. Set read state E to 5. When the read state E is 5, CNT is obtained in step S302.
It is determined whether the count value of A matches PLSB,
If YES (when the trailing edge of the document passes the reading position 190), the reading flag is reset to "0" in step S303, the counter CNTA is reset, and the reading state E is set to 6.

When the reading state E is 6, it is determined in step S304 whether or not the count value of CNTD matches PLSD, and if YES (when the trailing edge of the document passes through the second reading roller 2203), In step S305, the carry motor M2 is turned off and the counter CNTD is reset. Further, the switchback flag is set to "1" and the read state E is set to 7.

When the read state E is 7, when it is confirmed in step S306 that the in-switchback flag is reset to "0", the read state E is reset to 0 in step S307.

FIG. 42 shows steps S199, S221 and S.
265 illustrates a switchback subroutine executed at 265. Here, the document is introduced into the circulation reversing unit 2300 to reverse the front / back / front and back of the document, and the first reading roller pair 220
Process until resisting with 1.

First, in step S311, the inversion state C is set.
Check the count value of and execute the following processing according to the count value. When the reversal state C is 0, when the on-edge of the circulation reversal sensor SE4 is confirmed in step S312 (when the leading edge of the document reaches the sensor SE4), the counter C of the sheet feeding motor M1 is counted in step S313.
Start NTG and set inversion state C to 1.

If the inversion state C is 1, step S
In 314, it is determined whether or not the count value of CNTG matches PLSG. If YES (when the trailing edge of the document passes through the resin film 2304), the paper feed motor M1 is turned off and the solenoid SL1 is turned off in step S315. Then, the counter CNTG is reset. At the same time, in step S316, the paper feed motor M1 is set to CCW and turned on, and the reverse state C is set to 2.

When the inversion state C is 2, step S
When the on-edge of the registration sensor SE2 is confirmed in 317 (when the leading edge of the document reaches the sensor SE2), the timer TMRFB is started in step S318, and the inversion state C is set to 3. When the inversion state C is 3, after confirming the end of the timer TMRFB in step S319, the timer TMRFB is reset in step S320, the sheet feeding motor M1 is turned off, and the switchback flag is reset to "0". Reset the inversion state C to 0.

43 and 44 show steps S176 and S2.
00, the size detection 2 subroutine executed in S267 is shown. Here, the size of the original is determined by the registration sensor S.
Detect with E2. First, when it is determined in step S331 that the registration sensor SE2 is off-edge, the count value of the counter MPLSCNT is stored as SIZCNT in step S332, and MPLSCNT is reset. MPLSCNT counts the number of drive pulses of the carry motor M2 after it is turned on, and the sensor SE
Count value SIZCNT when 2 is off edge
Corresponds to the length of the document that has passed the sensor SE2.

Next, in step S333, the value of SIZCNT is checked and compared with the first and second values corresponding to the predetermined size. If SIZCNT is less than or equal to the first value, the length B is stored as "1" in step S334, and whether the width is "1" or "2" (see steps S65 and S69) is determined in steps S335 and S337. judge. If the width is "1", the document size is stored as "01" in step S336. If the width is "2", the document size is stored as "04" in step S338. If the width is not "1" or "2", the document size is stored as "07" in step S339.

If SIZCNT is greater than the first value and less than or equal to the second value, the length B is determined in step S340.
Is stored as “2”, and the width is “1” or “2” in steps S341 and S343 (see steps S65 and S69).
Or not. If the width is "1", step S34
In step 2, the document size is stored as "02". Width is "2"
If so, the document size is stored as "05" in step S344. If the width is not "1" or "2", the document size is stored as "08" in step S345.

If SIZCNT is larger than the second value, the length B is stored as "3" in step S346,
The width is "1" or "2" in steps S347 and S349.
(See steps S65 and S69). If the width is "1", the document size is set to "0" in step S348.
3 ”is stored. If the width is“ 2 ”, step S3
In step 50, the document size is stored as "06". If the width is not "1" or "2", the document size is stored as "09" in step S351.

45, 46, and 47 show the vibration suppressing subroutine executed in step S9. First, after confirming that the carry motor M2 is turned on in step S361, the speed Vm is checked in step S362. Three speeds are available: low speed range, medium speed range, and high speed range.
It is a type, processes steps S363 to S368 in the low speed range, processes steps S369 to S374 in the medium speed range, and processes steps S375 to S380 in the high speed range.

In the low speed range, the carrying is carried out in step S363.
Vibration frequency f of feed motor M2_MCheck. Vibration circumference
Wave number f_MIs lower than 100Hz, 2 above 100Hz
Classified into 3 types of 200Hz or higher, lower than 00Hz
Has been. Then, each step S364, S365, S
At 366, the vibration level Vf is the threshold value V of the vibration level.
f ₁, Vf₂, Vf₃If it is determined to be larger than
Drive current value Il and minimum current value of the motor M2 in step S367.
Il_minCompare with. And Il ≧ Il_minWhen,
In step S368, the drive current value Il is decreased by a constant value i
Let

Similarly, in the medium speed range and the high speed range, when the vibration level Vf is larger than the respective threshold values, and the drive current values Im and Ih are the minimum current values Im _min and Ih _min or more (step S373, If YES in S379), the drive current values Im and Ih are decreased by a constant value i (steps S374 and S380). Then, when it is confirmed that the paper feed motor M2 is turned off in step S381, the current values Il, Im, and Ih are set to initial values in step S382.

48 and 49 show a paper discharge subroutine executed in step S10. Here, the original is read straight from the reading unit 2200, or the paper output reversing unit 2 is used.
The sheet is discharged onto a sheet discharge tray 2502 through 400. First, after confirming that the paper discharge flag is set to "1" in step S391, the transport mode is checked in step S392, and the following processing is executed according to the value.

The transport modes are "01" to "05", "1".
If 0 "(straight paper ejection), the count value of the paper ejection state A is checked in step S393, and the following processing is executed according to the count value. When the paper ejection state A is 0, registration is performed in step S394. Sensor SE2
When the off-edge of the
When the sheet discharge state A is set to 1, the counter CNTH of the sheet discharge motor M3 is started in step S395.
Set to.

If the discharge state A is 1, step S
In 396, it is determined whether or not the count value of CNTH matches PLSH. If YES, the deceleration of the discharge motor M3 is started and the discharge state A is set to 2 in step S397. When the discharge state A is 2, step S3
At 98, it is determined whether or not the count value of CNTH matches with PLSI, and if YES (when the trailing edge of the document passes through the discharge roller pair 2501), the discharge motor M3 is turned off at step S399, and the counter CNTH is reached. Is reset, the discharge flag is reset to “0”, and the discharge state A is reset to 0.

On the other hand, the transport mode is "06" to "09".
In the case of (reverse ejection), the count value of the ejection state B is checked in step S400, and the following processing is executed according to the count value. When the discharge state B is 0, when the on-edge of the discharge sensor SE5 is confirmed in step S401 (when the leading edge of the document reaches the sensor SE5), the counter C of the discharge motor M3 is detected in step S402.
Start NTI and set paper ejection state B to 1.

If the discharge state B is 1, step S
In 403, it is determined whether or not the count value of CNTI matches PLSJ. If YES (when the trailing edge of the document passes through the resin film 2403), the discharge motor M3 is turned off in step S404, and the counter CNTI is reset. To do. At the same time, in step S405, the discharge motor M3 is set to CCW and turned on, the solenoid SL2 is turned off, and the discharge state B is set to 2. As a result, the original is reversed front / back / front and back and is conveyed toward the paper discharge roller pair 2501.

If the discharge state B is 2, step S
When the off edge of the paper discharge reversal sensor SE3 is confirmed in 406 (when the trailing edge of the document passes the sensor SE3), the counter CNTJ of the paper discharge motor M3 is started and the paper discharge state B is set to 3 in step S407. If the discharge state B is 3, it is determined in step S408 whether the count value of CNTJ matches PLSK, and YES.
If so, in step S409, the discharge motor M3 starts decelerating, and the discharge state B is set to 4.

If the discharge state B is 4, step S
In 410, it is determined whether or not the count value of CNTJ matches PLSL, and if YES (when the trailing edge of the document passes through the discharge roller pair 2501), the discharge motor M3 is turned off in step S411, and the counter CNTJ is counted. Is reset, the discharge flag is reset to “0”, and the discharge state B is reset to 0.

FIG. 50 shows a subroutine for communication with the CPU of the copying machine main body 10 executed in step S11. Here, the data from the main body CPU is received in step S421, and the data is transmitted from the CPU 3000 to the main body CPU in step S422.

(Second Embodiment) The second embodiment is shown in FIG.
51 has the same configuration as that of the first embodiment shown in FIG. 11 except that the intermediate conveying roller pair 2105 is omitted. As shown in FIG.
The paper feed roller 2103 is not driven at the time of reading an image to prevent noise when the trailing edge of the document passes through the rollers 2103 and 2104.

The positional relationship between the transport members is expressed by the following equation (11),
It is set to satisfy (12). (L ₁₁ + L ₁₂ ) <L _P1 (11) (L ₁₁ + L ₁₂ + L ₁₃ )> L _P2 (12) L ₁₁ : Distance between rollers 2103 and 2104 to first reading roller pair 2201 L ₁₂ : No. 1 reading roller pair 2201 to reading position 190
Distance L ₁₃ : Reading position 190 to second reading roller pair 2203
Distance L _P1 : Length of original of predetermined size L _P2 : Length of original that is one size longer than the above size

When the respective members are set so as to satisfy the above expressions (11) and (12), the rear end of the original having the length L _P1 or less is fed / sorted before the front end reaches the reading position 190. Since the rollers 2103 and 2104 pass through the rollers, fluctuations in the document tension that occur when the trailing edge is pulled out do not adversely affect image reading. Further, for a document having a length L _P2 or more, the rear end of the document passes through the sheet feeding / sorting rollers 2103 and 2104 when being nipped and conveyed by both the first and second reading roller pairs 2201 and 2032. Even if the document tension fluctuates when the trailing edge is pulled out, the document is pinched by the roller pairs 2201 and 2033 at the reading position 190, and the influence of noise can be suppressed.

Further, in the second embodiment, as in the first embodiment, the following expression (13) is satisfied in order to shorten the reading time per original and improve the image reading efficiency.
In addition, the distance L ₁₂ is shortened. (L ₁₁ + L ₁₂ −L ₁₄ ) / V ₀₄ ≦ L ₁₁ / V ₀₁ (13) L ₁₄ : Paper feed / separation rollers 2103 and 2104 to distance between width size reference sensors SE6 V ₀₁ : Pickup roller 2102, supply Paper roller 210
Transport speed V ₀₄ : transport speed of the pair of reading rollers 2201 and 2203

Here, the document conveying operation in the above configuration will be described. The paper feed roller 2103 is directly connected to the paper feed motor M1, and the first document is the pickup roller 2
102 is picked up by the paper feed / separation roller 210
And the first reading roller pair 2201
The sheet is registered at the nip portion (paper feed motor M1 is once off). After that, the document passes through the reading unit 2200 by turning on the conveyance motor M2, and the image is read. When the trailing edge of the document passes the width size reference sensor SE6, the paper feed motor M1 is turned on and the conveyance of the second document is started. Further, the conveyance motor M2 is turned off at the timing when the trailing edge of the first document passes the reading position 190, and the leading edge of the second document stops rotating at the nip portion of the first reading roller pair 2201. Be registered. Hereinafter, the same operation is repeated.

Next, the circulation reversing unit 2300 and the discharge reversing unit 2
The transport drive system in 400 and the discharge unit 2500 will be described. In the second embodiment, as shown in FIGS. 52 to 54, the circulation reversing roller pair 23 is driven by the paper discharge motor M3.
02, paper discharge reversing roller pair 2402 and paper discharge roller pair 25
01 is driven.

Specifically, the gear 2390 fixed to the output shaft of the paper discharge motor M3 meshes with the gear 2391 fixed to one drive shaft 2302a of the circulation reversing roller pair 2302 and the idle gear 2490. This idle gear 2
490 meshes with another idle gear 2491. The idle gear 2491 is configured integrally with the pulley 2492, and the pulley 2492 is connected to the pulley 2494 via the belt 2493. This pulley 2
Reference numeral 494 denotes one of the drive shafts 24 of the pair of discharge reversing rollers 2402
It is fixed to 02a. A pulley 2590 independent of the pulley 2494 is attached to the drive shaft 2402a via a one-way clutch.
When 2a is rotationally driven in the CW direction, the one-way clutch is connected and the pulley 2590 also rotates in the same direction.
Further, the pulley 2590 is connected to the idle pulley 2592 via the belt 2591.
An idle gear 2593 formed integrally with 592 meshes with a gear 2594 fixed to one drive shaft 2501a of the paper discharge roller pair 2501.

On the other hand, as shown in FIG. 54, a pulley 2596 is fixed to the drive shaft 2402a of the paper discharge reversing roller pair 2402, and the pulley 2596 is attached to the drive shaft 2501a of the paper discharge roller pair 2501 via a belt 2597. Is connected to the pulley 2598. The pulley 2598 is attached to the drive shaft 2501a via a one-way clutch, and when the pulley 2598 is rotationally driven in the CCW direction, the one-way clutch is connected to drive the drive shaft 251a.
01a also rotates in the same direction.

In the above drive system, when the paper discharge motor M3 rotates in the CW direction (see FIG. 53), the drive shaft 2302
a rotates in the CCW direction, the drive shaft 2402a rotates in the CW direction, and the drive shaft 2501a rotates in the CCW direction. on the other hand,
When the paper discharge motor M3 rotates in the CCW direction (see FIG. 54), the drive shaft 2302a rotates in the CW direction, and the drive shaft 2
402a rotates in the CCW direction and drive shaft 2501a rotates in the CCW direction. The speed ratio of the circulation reversing roller pair 2302: the paper ejection reversing roller pair 2402: the paper ejection roller pair 2501 is 1: 1: 1 when the paper ejection roller pair 2501 is rotationally driven via the gear 2593. , Belt 2597
1: 1/1 / u (u>
It is set to 1). Then, the circulation reversing roller pair 23
02 and the discharge reversal roller pair 2402 are set to be always the same speed as the reading rollers 2201 and 2203.

Further, the arrangement relationship of each conveying member is as follows. L ₁₅ : second reading roller pair 2203 to paper discharge roller pair 25
01 distance L ₁₆ : deceleration position 2520 in single-sided original mode-paper discharge roller pair 2501 distance L ₁₇ : second reading roller pair 2203-circulation reversing roller pair 2302 distance L ₁₈ : second reading roller pair 2203-resin Film 23
04 between the distance L _19: second read rollers 2203 and discharge inversion rollers 2402 between the distance L _20: second read rollers 2203 and the resin film 24
03 distance L ₂₁ : distance between resin film 2403 and paper discharge roller pair 2501

In the single-sided original mode, when the trailing edge of the original reaches the deceleration position 2520 after completion of reading, the paper discharge motor M3 rotating in the CW direction is switched to the CCW direction.
The first document is discharged onto the discharge tray 2502 at the speed V ₀₄ / u. At this time, the second original is conveyed at the speed V ₀₄ from the distance L _{12 and} the distance between the two originals is reduced.
At this time, the trailing edge of the first document is the pair of discharge rollers 2501.
The leading edge of the second document is ejected from the eject roller pair 25
In order to reach 01, it is necessary to satisfy the following expression (14). L ₁₃ + (L ₁₅ + L ₁₆ ) + L ₁₆ u <L ₁₂ + L ₁₃ + L ₁₅ ∴L ₁₆ (u-1) <L ₁₂ (14)

In the double-sided original mode, the original is conveyed to the upper left by the pair of discharge reversing rollers 2402 after the reading of the second side is completed. At this time, the trailing edge of the original is the resin film 240.
After exiting 3, the paper discharge motor M rotating in the CCW direction
3 is switched to the CW direction, and the document is switched back and conveyed toward the paper discharge roller pair 2501. At this time, the second original is conveyed toward the circulation reversing roller pair 2302, but the rear end of the first original is the resin film 24.
If the leading edge of the second document reaches the circulation reversing roller pair 2302 before leaving 03, the circulation reversing roller pair 2302 is rotating in the CW direction and the second document is jammed. Will end up. In order to prevent this, it is necessary to satisfy the following expression (15). L ₁₃ + L ₁₉ −L ₂₀ <L ₁₂ + L ₁₃ + L ₁₇ ∴L ₁₉ −L ₂₀ −L ₁₇ <L ₁₂ (15) Also, before the trailing edge of the first document passes through the discharge roller pair 2501. In addition, the rear end of the second original is a resin film 230.
If it does not reach 4, the discharge motor M3 continues to rotate in the CW direction, and thus the discharge speed of the first sheet cannot be reduced. In order to prevent this, it is necessary to satisfy the following expression (15 ′). L ₁₃ + L ₁₉ -L ₂₀ + L ₂₁ + L _P > L ₁₂ + L ₁₃ + L ₁₇ -L ₁₈ + L _P ∴L ₁₉ -L ₂₀ + L ₂₁ -L ₁₇ + L ₁₈ > L ₁₂ ...... (15 ')

By satisfying the above equation (15),
The trailing edge of the document that has been read is the pair of paper output reversing rollers 240.
The paper discharge motor M3 is driven to rotate in the CCW direction until it exits the resin film 2403 by 2.
By executing the control of switching to the CW direction again at the timing of leaving 403, the second side of the double-sided original is automatically
The circulation switchback operation for surface reading, the discharge switchback operation for a document after the reading of double-sided images, and the deceleration at the time of paper discharge can be executed almost in the same manner, and the image reading efficiency can be improved.

(Third Embodiment) The third embodiment is shown in FIG.
It consists of the basic configuration and arrangement shown in. In addition, the first,
Members having the same actions as those in the second embodiment are designated by the same reference numerals. Paper feed unit 2100: A document tray 2101, a pickup roller 2102, a paper feed roller 2103, a separation roller 2104, and the like. Reading unit 2200: first and second reading roller pair 220
1, 203, and a pressure contact guide plate 2202 and the like.

Reversing / paper discharging unit 2900: Reversing / paper discharging roller pair 2901, holding roller pair 2902, paper discharging tray 290
3, the recirculation path 2905, etc., the reversal position 29
04 and document holding position 2906 are set. Here, a switchback for reading the second side of the double-sided original, a switchback for aligning the original pages after the completion of the second side reading, and a sheet discharge are processed. The reversing / discharging roller pair 2901 includes a driving roller 2901a and a driven roller 2901.
and the drive roller 2901a can be rotated in the forward and reverse directions. The holding roller pair 2902 cooperates with the roller pair 2901 to read the original from the circulating conveyance path 2905.
The document is conveyed toward 0, or the document is stopped at the nip portion. Further, the conveying force of the roller pair 2902 (friction force against the document) is set to be sufficiently larger than that of the roller pair 2901.

Next, the outline of the carrying operation will be described. In the single-sided original mode, first, the originals set on the tray 2101 are sequentially fed one by one from the uppermost layer with the image side facing upward, and the images are passed through the reading unit 2200 with the image side facing downward. Read / Reverse / Discharge Roller Pair 290
The sheet 1 is discharged onto the tray 2903 with the image surface facing downward.

In the double-sided original mode, paper feeding and first side reading are the same as in the single-sided original mode. After the reading of the first side is completed, when the trailing edge of the document reaches the reversal position 2904, the reversal / paper discharge roller pair 2901 is reversed, and the circulation conveyance path 29 is rotated.
Switched back to 05. After that, the reading unit 220
The second surface is read after passing 0, and is switched back again to be conveyed to the circulation conveyance path 2905.

If there is no next original, the original is read by the reading unit 22.
00 is passed through without performing a reading operation, and is discharged from the reversing / paper discharging roller pair 2901 onto the tray 2903 with the first surface thereof facing downward. On the other hand, if there is a next original, the first original is stopped in the circulation conveyance path 2905 by stopping the rotation of the holding roller pair 2902. Then, while the second original is fed and the first side is read, the first original is passed through the reading unit 2200 after the second original. After that, the second original is switched back to be conveyed to the circulation conveyance path 2905, and the first original is discharged and the second original is read on the second surface. The above operation is repeated until the originals on the tray 2101 are exhausted.

Here, the length of each transport path and the transport speed will be described. La: Distance between document front end on tray 2101-paper feed / separation rollers 2103, 2104 Lb: paper feed / separation rollers 2103, 2104 ~ distance between first reading roller pair 2201 Lc: paper feed / separation rollers 2103, 2104 Distance Ld between width size reference sensors SE6: registration sensor SE2 to first reading roller pair 22
01 distance Le: first reading roller pair 2201 to reading position 190
Distance Lf: Reading position 190 to second reading roller pair 2203
Distance Lg: Second reading roller pair 2203 to reverse position 2904
Distance Lh: Pre-reverse sensor SE21 to reverse position 2904 Distance Li: Reverse position 2904 to reverse / paper discharge roller pair 2901
Distance Lj: Reverse position 2904 to holding roller pair 2902 Distance Lk: Reverse position 2904 to post-reverse sensor SE22 distance Ll: Holding roller pair 2902 to original holding position 2906 Distance Lm: Original holding position 2906 to first reading roller Pair 22
01 distance

V ₂₁ : Conveying speed of pickup roller 2102 and paper feeding roller 2103 V ₂₂ : Conveying speed of reading roller pair 2201, 203 during reading V ₂₃ : Conveying speed of reading roller pair 2201, 203 other than during reading V ₂₄ ( = V ₂₂ ): Conveyance speed at the time of reading the reversal / discharge roller pair 2901 V ₂₅ (= V ₂₃ ): Conveyance speed of the reverse / discharge roller pair 2901 and the holding roller pair 2902 V ₂₆ : Reversal / discharge roller pair Transport speed of 2901 when ejecting paper

In order to prevent the trailing edge and leading edge of one original from being simultaneously pinched in the nip portion of the pair of reversing / delivering rollers 2901, let the maximum length of the original be Lmax, and the following formula (1
It is necessary to satisfy 6). Le + Lf + Lg + 2Li + Lj + Ll + Lm> Lmax (16)

Until the first original is sandwiched by the holding roller pair 2902, the second original is reversed / discharge roller pair 29.
In order not to reach 01, it is necessary to satisfy the following expression (17). (Lf / V ₂₂ ) + {(Lg + Lj + Ll) / V ₂₅ } <(Le + Lf + Lg + Li) / V ₂₂ (17) However, here, as in the first embodiment, the rear end of the first document is the reading position. It is assumed that the leading edge of the second document reaches the first reading roller pair 2201 while waiting at the position where it has passed 190. In addition, V ₂₂ ≤V ₂₃ , V ₂₆ ≤V in order to shorten the transport time as much as possible except during the reading operation.
It is set to ₂₄ ≤ V ₂₅ . Further, at the time of discharging to the tray 2903, the speed V ₂₆ is kept low so as not to disturb the consistency on the tray 2903.

Next, the document feeding operation in the double-sided document mode will be described in detail with reference to FIGS. 56 to 70. Note that FIG.
61 to 61 show the carrying operation when there is one double-sided document, and FIGS. 62 to 70 show the carrying operation when there are two or more double-sided documents.

First, the first original D ₁ is fed by the pickup roller 2102 and the feed roller 2103 at a speed V ₂₁ , and the registration sensor SE2 detects the leading edge of the original D _1. When an appropriate amount of bending is made on the upstream side of the nip portion of the pair 2201, the conveyance is stopped and the resist processing is performed (FIGS. 56, 57 and 62, 63).
reference).

Next, the reading roller pairs 2201 and 2032
Then, the document D ₁ is conveyed at a speed V ₂₂ and the image on the first side is read. When the front end of the document D ₁ is detected by the pre-reversal sensor SE21, the drive roller 2901a is rotated in the CCW direction at the speed V ₂₄ at the timing of reaching the reversal / paper discharge roller pair 2901. As a result, the document D ₁ is conveyed to the left, and when the trailing edge of the document D ₁ passes the reading position 190, the speed of the reading roller pair 2201 and 2032 is set to V ₂₃ .
The speed of the drive roller 2901a is changed to V ₂₅ . Document D
_When the rear end of ₁ is detected by the pre-reversal sensor SE21, the rear end reaches the reversal position 2904 (see FIG.
8, see FIG. 64), the drive roller 2901a is set in the CW direction and rotated at the speed V ₂₅ . As a result, the document D ₁ is conveyed to the circulation conveyance path 2905 with its front and back reversed.

Next, when the document D ₁ is conveyed by the holding roller pair 2902 rotating at the speed V ₂₅ , and the front and back sides are reversed and the leading edge is detected by the registration sensor SE2, the same as in the above-mentioned sheet feeding operation. A resist process is performed in which a proper amount of curvature is formed on the sheet and stopped immediately before the first reading roller pair 2201 (see FIGS. 59 and 65). Note that the reading roller pairs 2201 and 2033 are stopped rotating when the trailing edge of the document D ₁ passes through the second reading roller pair 2203.

Next, in order to read the second surface, the reading logic
The speed of the roller pair 2201 and 2203 _{twenty two}When driven with
A holding roller pair 2902 and a reversing / paper discharging roller pair 29.
01 for speed V_{twenty four}Drive with. After that, when reading the first side
Similarly, the drive roller 2901a moves at the speed V_{twenty five}so
Driven.

When the trailing edge of the document D ₁ passes the registration sensor SE2, the presence or absence of the document on the tray 2101 is checked. If there is no document, the trailing edge of the document D ₁ is at the reading position 19
When 0 is passed, the reading roller pair 2201 and 2203 are changed to the speed V ₂₃ , and the reversing / paper discharging roller pair 290 is changed.
1 is changed to the speed V ₂₅ , and the document D ₁ is switched back (see FIG. 60) in the same manner as described above and is conveyed to the circulation conveyance path 2905. When the leading edge of the document D ₁ reaches the registration sensor SE2, the reading roller pairs 2201 and 2032 are driven at a speed V ₂₃ , and the document D ₁ is read without a reading operation by the reading unit 220.
0 is passed through. Then, at the timing when the leading edge of the document D ₁ reaches the reversal / paper discharge roller pair 2901, the rotation of the drive roller 2901a is changed in the CCW direction and at the speed V ₂₅ . Further, the rear end of the document D ₁ is the sensor SE before reversal.
After passing 21, the speed of the reversing / paper discharging roller pair 2901 is reduced to V ₂₆ at a predetermined timing, and the document D ₁ is discharged onto the tray 2903 (see FIG. 61).

On the other hand, when the rear surface of the document D ₁ is read on the second side and the trailing edge of the original D ₁ passes the registration sensor SE2, the tray 210
If there is the second original D ₂ on 1, to feed the paper toward the original D ₂ to the first read rollers 2201 similarly said.
At this time, the trailing edge of the _first document D ₁ is at the reading position 190.
When the sheet has passed through, the rotations of the reading roller pairs 2201 and 2032 are stopped to prepare for the registration process of the _second document D ₂ (see FIG. 66). At this time, the reversal / paper ejection roller pair 2
901 also stops the rotation.

Next, the reading roller pair 2201 and 2032 are driven at the speed V ₂₂ to read the first surface of the _second document D ₂ , and at the same time, the driving roller 2901a is also driven at the speed V ₂₄ in the CCW direction. . After that, the first document D ₁ is switched back as in the case of the first side reading and is conveyed to the circulation conveyance path 2905. The leading edge of the document holding position 290
When it reaches 6, the holding roller pair 2902 and the reversal / paper discharge roller pair 2901 are once stopped. Then, the drive roller 2901a is driven at a speed V ₂₄ in the CCW direction at the timing when the leading edge of the _second document D ₂ reaches the reversal / paper discharge roller pair 2901. At this time, as shown in FIG.
The _first original document D ₁ is also sandwiched in the nip portion of the reversal / discharge roller pair 2901, but the drive roller 2901a is C
Even if the holding roller pair 2902 is rotated in the CW direction, the holding force of the holding roller pair 2902 is set to be sufficiently larger than the conveying force of the reversing / paper discharging roller pair 2901, so that the first document D ₁ is held by the holding roller pair 2902. It is held and stopped. Then, the second document D ₂ is conveyed to the left under the _first document D ₁ by the drive roller 2901a.

The reading position 19 is at the rear end of the _second document D _2.
After passing 0, the holding roller pair 2902 is driven at the speed V ₂₅ , and the first document D ₁ is conveyed toward the reading unit 2200. At this time, the rear end of the _second document D ₂ is conveyed toward the reverse position 2904 in the direction opposite to that of the _first document D ₁ . That is, since the larger the friction coefficient of the original D _1, the driving than the friction coefficient between the D ₂ roller 2901a and the original D _2, the document D _1, D ₂ are each other according to the rotation of the respective retaining rollers 2902 and drive rollers 2901a Transported in the opposite direction. Then, the driven roller 2901b is driven to rotate in the CCW direction until the trailing edge of the _first document D ₁ is removed,
After that, the second original D ₂ is contacted and driven to rotate in the CW direction. Note that the rear end of the _second document D ₂ is at the reading position 1
Upon passing 90, the reading roller pair 2201, 22
03 is changed to the speed V ₂₃ , and the driving roller 2901a is changed to the speed V ₂₅ .

Next, when the leading edge of the _first original D ₁ reaches the registration sensor SE2, the reading roller pair 2201,
2203 is driven at a speed of V ₂₃ and passes through the reading unit 2200 without any reading operation. Second document D
_When the trailing edge of ₂ passes the reverse position 2904, the drive roller 2901a is switched in the CW direction, and the first document D
_If the trailing end of ₁ has passed the post-reversal sensor SE22, if it has not passed, the passage is waited for and the conveyance to the circulation conveyance path 2905 is started.

When the trailing edge of the _first original D ₁ is detected by the registration sensor SE2, the trailing edge of the _first original D ₁ is read by the first reading roller pair 2.
Reading roller pair 220 at the timing of exiting 201
The rotation of 1,203 is stopped. Then, the leading edge of the _second document D ₂ comes into contact with the first reading roller pair 2201,
A resist process is performed (see FIG. 68). For this resist processing, the distance Lk from the reversal position 2904 to the post-reversal sensor SE22 is set to be larger than the resist curving amount.

Next, the reading roller pairs 2201 and 2032
Is driven at a speed V ₂₂ to read the second surface of the second original D ₂ and the _first original D ₁ is transferred to the tray 2903.
It is discharged upward (see FIG. 69). When the trailing edge of the _second document D ₂ passes the registration sensor SE2, the presence or absence of the next document on the tray 2101 is checked as described above, and the above operation is repeated.

Next, the reading efficiency in the above conveying operation will be examined. The first reading roller pair 2201 is fed by feeding the second original after the feeding of the first original is started.
The time Ta until the registration is completed is
If p and the resist curve amount are Ln, they are expressed by the following equation (18). Ta = {(La + Lb + Ln) / V 11} + {(Lp + Le) / V 12} + {(Lf + Lg) / V 23} + {(Lj + Ll + Lm + Ln) / V 23} + {(Lp-Ld) / V 22} + { (La + Lb + Ln) / V ₁₁ } (18)

Further, the time Tb from the completion of registration of the second document to the completion of registration of the third document by feeding the third document is expressed by the following equation (19). Tb = {(Lp + Le) / V 22} + {(Lf + Lg) / V 23} + [{(Lm + Lp) - (Lj + Ll-Lk)} / V 23}] - {(Lf + Lg) / V 23} + {(Lj + Ll + Lm + Ln _{) / V 23} + {(} Lp-Ld) / V 22} + {(La + Lb + Ln) / V 11} ...... (19)

In the equation (19), the time indicated by the third and fourth terms on the right side is the reverse position 290 at the rear end of the second sheet.
After reaching the point 4, the rear edge of the first sheet is reversed and the sensor SE
It means the time until the sheet passes through 22, and delays the start of conveyance to the circulation conveyance path 2905 for the second sheet in order to enable the resist processing (formation of an appropriate amount of curvature) when reading the second side of the second sheet. I am letting you. However, when the third and fourth terms have negative values (third term <fourth term), when the trailing edge of the second sheet reaches the reversal position 2904, the trailing edge of the first sheet has already been reached. Has passed the registration sensor SE2. In this case, the value of "third term-fourth term" is 0.

Based on the above equations (18) and (19), the processing time Tn for n originals (n is 2 or more) is given by the following equation (20).
Indicated by. Tn = Ta + Tb (n-1) (20) For comparison, the processing time in the conventional document feeder will be described. With the conventional method, a double-sided original is reversed for the third time in order to align the pages on the discharge tray.
This is a method in which the feeding of the next original is started after the sheet has passed the reading section for the third time. In this conventional method, the time Tc from the start of feeding the first document to the completion of registration is expressed by the following equation (21). Tc = (La + Lb + Ln) / V ₁₁ (21)

The time Td from completion of registration of the first original to completion of feeding / registration of the second original is expressed by the following equation (2
It is represented by 2). Td = (Lp + Le) / V 12 + (Lf + Lg) / V 13 + (Lj + Ll + Lm + Ln) / V 13 + (Lp + Le) / V 12 + (Lf + Lg) / V 13 + (Lj + Ll + Lm) / V 13 + (Lp-Ld) / V ₁₃ + (La + Lb + Ln) / V ₁₁ (22)

Based on the above equations (21) and (22), the processing time Tn for n originals (n is 2 or more) is given by the following equation (23).
It is clear that the time loss is large compared with the third embodiment. Tn = Tc + Td · n (23)

FIG. 71 is a graph showing the relationship between the number of reading surfaces and the processing time for a double-sided original. The processing time in the first and third embodiments of the present invention is shorter than that in the conventional method. The difference becomes clearer as the number of manuscripts increases.

(Other Embodiments) The document feeder according to the present invention is not limited to the above-mentioned embodiment, but can be variously modified within the scope of the gist thereof.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an electrophotographic copying machine main body provided with a document feeder according to a first embodiment of the present invention.

FIG. 2 is an internal configuration diagram showing the document feeder.

FIG. 3 is an explanatory view showing a transport path length of the document transport device.

FIG. 4 is an explanatory view showing an opened state of the document feeder.

FIG. 5 is an explanatory diagram showing a transport drive system of the document transport device.

FIG. 6 is a plan view showing a document width size detection mechanism in the document feeder.

FIG. 7 is an operation explanatory view of the width size detection mechanism.

FIG. 8 is a detection time chart of the width size detection mechanism.

FIG. 9 is a chart showing an excitation pattern of a carry motor.

FIG. 10 is a time chart diagram of two-phase excitation.

FIG. 11 is a time chart diagram of 1-2 phase excitation.

FIG. 12 is a block diagram showing a control circuit.

FIG. 13 is a block diagram showing a control circuit of a carry motor.

FIG. 14 is a flowchart showing a main routine of a control procedure.

FIG. 15 is a flowchart showing a tray raising / lowering subroutine.

16 is a flowchart showing a tray raising / lowering subroutine, continued from FIG. 15;

FIG. 17 is a flowchart showing a paper feeding subroutine.

FIG. 18 is a flowchart showing a paper feeding subroutine, continued from FIG. 17;

FIG. 19 is a flowchart showing a size detection 1 subroutine.

FIG. 20 is a flowchart showing the size detection 1 subroutine, continued from FIG. 19;

FIG. 21 is a flowchart showing the size detection 1 subroutine, continued from FIG. 20;

FIG. 22 is a flowchart showing a speed setting subroutine.

FIG. 23 is a flowchart showing a speed setting subroutine, continued from FIG. 22;

FIG. 24 is a flowchart showing a speed setting subroutine, continued from FIG. 23;

FIG. 25 is a flowchart showing a speed setting subroutine, continued from FIG. 24.

FIG. 26 is a flowchart showing a speed setting subroutine, continued from FIG. 25.

FIG. 27 is a flowchart showing a subroutine for setting an excitation pattern.

28 is a flowchart showing the excitation pattern setting subroutine, continued from FIG. 27.

FIG. 29 is a flowchart showing a reading subroutine.

FIG. 30 is a flowchart showing a reading subroutine, continued from FIG. 29.

FIG. 31 is a flowchart showing the reading subroutine, continued from FIG. 30.

FIG. 32 is a flowchart showing a subroutine of a first example of passing a reading unit.

FIG. 33 is a flowchart showing a subroutine of a second example of passing a reading unit.

FIG. 34 is a flow chart showing a subroutine of a third example of reading unit passage.

FIG. 35 is a flowchart showing the subroutine of the third example of passing the reading unit, continued from FIG. 34;

FIG. 36 is a flowchart showing a subroutine of a reading unit passing fourth example.

FIG. 37 is a flowchart diagram showing a subroutine of the fourth example of passing the reading unit, continued from FIG. 36;

FIG. 38 is a flowchart showing a subroutine of a reading unit passing fifth example.

FIG. 39 is a flowchart showing a subroutine of the fifth example of reading unit passing, continued from FIG. 38;

FIG. 40 is a flow chart showing a subroutine of a sixth example of passing a reading unit.

FIG. 41 is a flowchart diagram showing the subroutine of the sixth example of passing through the reading unit, continued from FIG. 40;

FIG. 42 is a flowchart showing a switchback subroutine.

FIG. 43 is a flowchart showing a size detection 2 subroutine.

FIG. 44 is a flowchart showing the size detection 2 subroutine, continued from FIG. 43;

FIG. 45 is a flowchart showing a vibration suppression subroutine.

FIG. 46 is a flowchart showing a vibration suppression subroutine, continued from FIG. 45.

FIG. 47 is a flowchart showing a vibration suppression subroutine, continued from FIG. 46.

FIG. 48 is a flowchart showing a paper discharge subroutine.

FIG. 49 is a flowchart showing a paper discharge subroutine, continued from FIG. 48.

FIG. 50 is a flowchart showing a subroutine of communication with the main body CPU.

FIG. 51 is an internal configuration diagram showing a document feeder according to a second embodiment of the present invention.

FIG. 52 is a plan view showing a transport drive system of the document transport device.

FIG. 53 is an elevation view of the transport drive system.

FIG. 54 is another elevation view of the transport drive system.

FIG. 55 is a schematic configuration diagram showing a document feeder according to a third embodiment of the present invention.

FIG. 56 is an explanatory diagram of the transport operation when one double-sided original is used.

FIG. 57 is an explanatory diagram of a transport operation when one double-sided original is fed, FIG.
Continued.

FIG. 58 is an explanatory diagram of a transport operation when one double-sided original is fed, FIG.
Continued.

FIG. 59 is an explanatory view of the transport operation when one double-sided original is fed, FIG.
Continued.

FIG. 60 is an explanatory diagram of a transport operation when one double-sided original is fed, FIG. 59.
Continued.

FIG. 61 is an explanatory diagram of a transport operation when one double-sided original is fed, FIG.
Continued.

FIG. 62 is an explanatory diagram of a transport operation when there are two or more double-sided originals.

FIG. 63 is an explanatory diagram of the transport operation when there are two or more double-sided originals, continued from FIG. 62.

FIG. 64 is an explanatory diagram of the transport operation when the number of double-sided originals is two or more, continued from FIG. 63.

FIG. 65 is an explanatory diagram of the transport operation when there are two or more double-sided originals, following FIG. 64.

FIG. 66 is an explanatory diagram of the transport operation when the number of double-sided originals is two or more, continued from FIG. 65.

FIG. 67 is an explanatory diagram of the transport operation when there are two or more double-sided originals, and is a continuation of FIG. 66.

FIG. 68 is an explanatory diagram of the transport operation when there are two or more double-sided originals, continued from FIG. 67;

FIG. 69 is an explanatory diagram of the transport operation when there are two or more double-sided originals, and is a continuation of FIG. 68;

FIG. 70 is an explanatory diagram of the transport operation when there are two or more double-sided originals, continued from FIG. 69.

FIG. 71 is a graph showing document reading processing efficiency.

[Explanation of symbols]

11 ... Image reading optical system 20. Document transport device 190 ... Reading position 2100 ... Paper feeder 2102 ... Pickup roller 2103 ... Paper feed roller 2200 ... reading unit 2201 ... 1st reading roller pair 2203 ... second reading roller pair 2300 ... Circulation inversion section 2400 ... Paper output reversing unit 2500 ... Paper output section 3000 ... CPU SE6: Document detection sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-64788 (JP, A) JP-A-4-148756 (JP, A) Fukuihei 1-12-11033 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B65H 5/06 G03G 15/00 107 H04N 1/00 108

Claims (3)

(57) [Claims] 1. A reading unit stationary near a reading position of an original image, a paper feeding unit for feeding the original, and a first feeding unit for feeding the fed original toward the reading position.
Transporting means, second transporting means for transporting the document at the reading position at a constant speed, a document detecting sensor provided between the first transporting means and the second transporting means, and the document detecting sensor A sheet feeding start unit that starts feeding the next document when the trailing edge is detected , and further satisfies the following expression: (L _A / V _A ) <(L _B / V _B ) L _a: sensor-reading position distance V _a: transport speed L _B by the second transport means: between the first conveying unit - second conveying means a distance V _B: document feeder, wherein the transport speed of the first conveying means. 2. A reading unit stationary near a reading position of the original image, a paper feeding unit for feeding the original, a conveying roller for conveying the fed original toward the reading position, and a reading roller for the reading position. A first roller disposed immediately before the second roller, a second roller disposed immediately after the reading position and configured to convey a document at the reading position at the same speed as the first roller; and between the conveyance roller and the first roller. A document detecting sensor, a stop means for stopping the first roller when the trailing edge of the document passes through the reading position, and the feeding of the next document when the document detecting sensor detects the trailing edge of the document. comprising a sheet feed starting means for starting the paper, and further, satisfies the following _{formula, (L a / V a)} <(L B / V B) L a: sensor-reading position distance V _a: No. Conveyance speed L _B by 1st roller and 2nd roller : Distance between transport roller and first roller V _B : Document transport device characterized by transport speed by the transport roller . 3. A stack of plural originals, one by one
Image picked up and imaged by a stationary image reading device
In the document transport device that transports documents at a constant speed at the scanning position
hand, Direct the documents picked up from the stack to the reading position.
Conveying roller for conveying the sheet, Immediately before the reading position on the downstream side of the transport roller
A first roller located at, A second roller located immediately after the reading position, Document located between the transport roller and the first roller
And a detection sensor, The leading edge of the document transported by the transport rollers does not rotate.
Even after the contact with the stopped 1st roller,
The first control step to continue driving the motor, The first roller, The second rollerCarry over the reading position by
When the trailing edge of the document to be fed passes the reading position, the first low
The drive of the printer
Start picking up the next document based on the detection signal
Performing a second control step, Furthermore, satisfy the following equation, (L_A/ V_A) <(L_B/ V_B) L_A: Distance between sensor and reading position V_A: Transport speed by the first and second rollers L_B: Distance between transport roller and first roller V_B: Transport speed by the transport roller A document feeder which is characterized by: