JPH11119596A - Image forming device and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device by which the transfer paper can be fed preceedingly by the main body of the device at the time of an original mixed-placement mode. SOLUTION: When the original mixed-placement mode is set, the size of an original document carried to an image reading position is checked (Step S102), and a transfer-paper feed cassette corresponding to the size of the original-document is selected (step S103). Thereafter the device judges whether an original-document rear-end sensor is off or not (step S104), and when it is not off, the operation is repeated until it is turned off. When the sensor is turned off, the size of an original is checked (step S105), a transfer-paper feed cassette corresponding to the size of the original is selected (step S106), and then the transfer paper can be fed preceedingly from this cassette (step S107).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine having an automatic document feeder, and a control method therefor.

[0002]

2. Description of the Related Art An image forming apparatus provided with an automatic document feeder that transports a document placed on a document tray to an image reading position and discharges the document to a discharge tray after image reading of the document has been completed has been conventionally known. More known.

In an image forming apparatus having an automatic document feeder of this type, when documents of different sizes are simultaneously set on a document tray of the automatic document feeder to form an image (in a mixed original mode), In the copy condition input section of the image forming apparatus, the original mixed mode is designated, the originals on the original tray of the automatic original feeder are transported one by one to the image reading position, and the original size is checked and then transferred. We were choosing paper.

[0004]

However, in the above conventional example, even when the same size originals are continuously fed from the automatic original feeder, the originals are transported one by one to the image reading position and the original size is reduced. Is checked, and the transfer paper is selected after the size is determined. For this reason, it takes a long time to start feeding the transfer paper, and the productivity of image formation has been significantly reduced.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide an image forming apparatus capable of pre-feeding a transfer sheet of an apparatus main body in a mixed document mode, and a control method therefor.

[0006]

According to a first aspect of the present invention, a document placed on a document tray is transported to an image reading position, and the document is discharged after the image reading of the document is completed. An automatic document feeder, size detecting means for detecting the size of the document, and selecting means for selecting a transfer paper feed cassette for the document based on the result of the size detecting means; An image forming apparatus for performing an image forming process of transferring an image to a selected transfer sheet, wherein first and second document detecting means for detecting a document on the document tray; and first and second document detecting means. Determining means for determining whether or not there is a document having a different length on the document tray based on the result; and when the determining means determines that there is no document having a different length, the selecting means determines whether or not there is a preceding document. Choose for In that a permission unit for permitting the leading feed from the transfer paper sheet cassette.

According to a second aspect of the present invention, in the first aspect of the invention, the preceding sheet feeding is performed in a mixed document loading mode in which documents of different sizes are simultaneously set on a document tray of the automatic document feeder to form an image. The sheet is fed during image formation from the transfer sheet feeding cassette selected for the preceding document.

In a third aspect based on the first or second aspect, there is provided a final document detecting means for detecting whether or not the document being conveyed is the final document, wherein the final document detecting means detects the final document. When the detection is detected, the preceding sheet feeding is prohibited.

In a fourth aspect based on the first to third aspects, the second document detecting means is disposed at a distance from the first document detecting means at which a long document can be detected. .

According to a fifth aspect of the invention, an original placed on an original tray is conveyed to an image reading position, and the original is discharged after the image reading of the original is completed, and the size of the original is detected. An image forming process that includes a size detection unit and a selection unit that selects a transfer paper feed cassette for a document based on the result of the size detection unit, and that transfers the image reading result to the selected transfer paper. First and second document detecting means for detecting a document on the document tray are provided for the image forming apparatus to be performed, and based on the results of the first and second document detecting means, And a transfer paper feed cassette selected for the preceding document by the selection means when it is determined that there is no document having a different length by the determination process. Precedence from It is obtained so as to perform the authorization process to allow paper.

According to a sixth aspect of the present invention, an automatic document feeder which conveys a document placed on a document tray to an image reading position and discharges the document after image reading of the document is completed, and detects the size of the document. An image forming process that includes a size detection unit and a selection unit that selects a transfer paper feed cassette for a document based on the result of the size detection unit, and that transfers the image reading result to the selected transfer paper. A first document detecting means for detecting a document on the document tray, and a second document detecting means disposed at a distance from the first document detecting means capable of detecting a long document. When a mixed document mode is set in which documents of different sizes are simultaneously set on the document tray of the automatic document feeder to form an image, the size of the document conveyed to the image reading position is checked. A second step of selecting a transfer paper feed cassette according to the size of the original, and after the second step, the detection result of the second original detecting means is a first detection. Performing a third step of determining whether the document is in one of a state and a second detection state. If the detection result of the second document detection means is the first detection state, the second detection state The first to third steps are repeatedly executed until the following condition is satisfied. Further, under the second detection state, a document size check is performed, and a transfer paper feed cassette according to the document size is selected. Later, the preceding sheet feeding from this cassette is permitted.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, the preceding sheet feeding is performed in a mixed document mode in which documents of different sizes are simultaneously set on a document tray of the automatic document feeder to form an image. The sheet is fed during image formation from the transfer sheet feeding cassette selected for the preceding document.

In an eighth aspect based on the sixth and seventh aspects, the apparatus further comprises a last document detecting means for detecting whether or not the document being conveyed is the last document, wherein the last document detecting means detects the last document. When the detection is detected, the preceding sheet feeding is prohibited.

[0014]

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

(Description of Apparatus) FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

In FIG. 1, A is an automatic document feeder.
The DF 2 has a document tray 4 above, and below it,
The wide belt 7 wound around the drive roller 36 and the other turn roller 37 is disposed. The document P (not shown) on the document tray 4 is sequentially separated from the topmost sheet,
The document is conveyed to a platen glass (platen) 3 which is a reading position of the copying machine body 1.

The wide belt 7 is in contact with the platen 3 and the sheet original P conveyed from the original tray 4
Is placed at a predetermined position on the platen 3, or the sheet document P on the platen 3 is carried out to the discharge tray 10.
The originals are placed on the original tray 4 in order of 1 page (2 pages), 3 pages (4 pages)... From the top.

The copier main body 1 includes an image input unit 200 (hereinafter referred to as a reader unit) and an image output unit 300 (hereinafter referred to as a printer unit). The reader unit 200 optically reads image information recorded on a document P, photoelectrically converts the image information, and inputs the image data as image data. The reader unit 200 includes a scanner unit 204 having a platen 3, a lamp 202, and a mirror 203; 206, lens 207,
It has an image sensor 208 and the like.

The printer unit 300 is a well-known image forming means and has a configuration described later.

The present invention is also applicable to a reader in which the reader unit 200 and the document feeder are integrated. Further, the copying machine main body 1 may include a document conveying device.

(Description of the Configuration of the Document Tray) A pair of width-direction regulating plates are slidably disposed in the document tray 4 in the width direction of the sheet document P. Is regulated in the width direction to ensure the stability of the sheet document P during feeding.

A rotating stopper 21 is provided at the end of the document tray 4 so that the sheet document P set on the document tray 4 is restricted by the protruding stopper 21 so that it cannot advance downstream. (FIG. 4).

(Description of Sensor on Tray) Stopper 21
Document set detection sensors 40a and 40b, which are transmission-type optical sensors for detecting that the sheet document bundle P is set, are provided near the upstream portion of FIG.

Further, in the middle of the document tray 4, there is provided a document trailing edge detection sensor 41 which is a reflection type optical sensor for determining whether the set document is a half size document. This sensor is located at a distance of 225 mm from the stopper 21. When a longitudinal document is set, the rear end detection sensor 41 is turned on.

A final document detection sensor 43, which is a reflection type optical sensor, is provided between the document set detection sensor 40 and the rear end detection sensor 41, and determines whether the document being conveyed is the last document. I can do it.

Further, a paper width detecting sensor 44 for detecting the length in the width direction of the document bundle P set on the document tray 4 by detecting the position of the width direction regulating plate is provided below the document tray 4. I have.

(Description of Separation Section) Above the document tray 4, as shown in FIG.
The swinging arm 53 is swing-restricted by an arm shaft 51c which is supported by the front and rear support plates 51a and 51b.

Normally, as shown in FIG. 5, which is the home position, the paper feed roller 5 is restrained by the shaft 51c, and is retracted above the upper separation guide plate 52 (suppressed by the pin 51g). The position is set so that the document setting work is not hindered. The elevating arm 51 is controlled by the motor 103 and is at the position shown in the figure, as will be described later.

FIG. 9 is a plan view of the separation structure according to the present invention. The elevating arm 51 rotates about the rotation axis center C1, and is movable from the position in FIG. 5 to the position in FIG.
As described above, the paper feed roller 5 is provided at the tip of the swing arm 57 or 53 that rotates around the rotation center axis C1. The swing arms 57 and 53 descend by their own weight with the movement of the lifting arm 51, and the paper feed roller 5 lands on the uppermost sheet of the document P and stops (the position in FIG. 8). By rotating the paper feed roller 5 in this state, the original can be sequentially conveyed from the uppermost sheet. The upper guide plate 52 is suppressed to the position shown in FIG. 6 by a stopper (not shown).

In the state shown in FIG. 8, the swing arms 57, 5
The arm shaft 51c supporting the arm 3 is released when the paper feed roller 5 lands on the sheet surface. At this time,
The relative positional relationship between the swing arms 57 and 53 and the lifting arm 51 starts to shift. The amount of this displacement is equal to the first swing arm flag 5 which is a part of the swing arms 57 and 53.
4. Second swing arm flag 55 and lifting arm 5
By the first swing position sensor 46 and the second swing position sensor 47 attached to 1, the non-detection state is changed to the detection state as shown in FIG. 8, so that the swing arm is controlled to stop.

In this state, the swing arms 57 and 53 and the paper feed roller 5 are placed on the sheet original bundle P stacked on the tray 4 by their own weight, and the sheet original P is always stably fed. It is possible to give power.

The elevating arm 51 is driven by a swing motor 103 (stepping motor), and the elevating arm 51 can take any position (position in FIG. 7) between FIGS. 5 and 6. .

A paper feed roller home sensor 45, which is a transmissive optical sensor, is mounted on a fixed support plate 56 above the separation section, and a raising / lowering arm flag 51d provided on swing arms 57 and 53 feeds paper. When the sensor optical path of the roller home sensor 45 is blocked, it is detected that the lifting arm 51 is at the standby position, which is the home position.

As described above, the first swing position sensor 46 which moves integrally with the lifting arm 51 and the second
A swing sensor 47 is provided, and swing arms 53 and 5 are provided.
The first swing arm flag 54 and the second swing arm flag 55 formed extending in the descending direction of No. 7 can be detected.

The above-described state shown in FIG. 7 is a retreat position during continuous sheet feeding, and the swing arms 57 and 53 do not need to return to the home position (the state shown in FIG. 5). It is controlled so that it stops intermediately at a position separated by a minimum amount (about 3 to 5 mm).

With this configuration, the paper feed roller 5
Can be minimized, and the landing vibration of the paper feed roller 5 on the sheet document P is reduced, which contributes to the improvement of the paper feeding performance. At the same time, the time until the start of the subsequent sheet feeding can be shortened, and sheet feeding control with a shorter sheet feeding interval can be performed.

When the feeding roller 5 starts the feeding operation in a bound state due to an impact upon landing on the sheet document P, the pressure balance of the front and rear feeding rollers against the sheet document P is lost, and the feeding roller 5 is inclined at the time of feeding. The probability of generating a row increases.

As shown in FIG. 9, a plurality of feed rollers 5 arranged in the width direction each have an independent suspension structure, and are easily equalized to the sheet bundle of originals P. It is possible to measure.

Downstream of the shutter 21 in the transport direction is provided a known separating section composed of a separation belt 6 and a separate transport roller 8, and performs a separating operation by rotating in the direction of the arrow (FIG. 8).

(Explanation of Conveyance Path) As shown in FIG. 3, a document feed path (a), (b), and (c) is formed from the document tray 4 to the platen 3, and this document feed path ( (B) (b) and (c) are bent (curved downward) and connected to the transport path (d) on the platen 3 to guide the sheet document P onto the platen 3.

A reversing feed path (h), (f), and (l) extends from the document transport path (b) so that the document can be turned upside down before the document is transported to the platen 3.

The document reversed in the reversing feeding path (h), (f), and (i) is switched back, conveyed to the platen 3 through the document feeding / discharging path (e), and placed.

Further, a document reversing path (G) is branched from the reversing feeding path (F) so that the document reversing path (G) can be merged with the document feeding path (B). (G)
By using (c), the original on the platen 3 is switched back, turned upside down, and can be returned to the platen 3 again.

After the reading of the image on the platen 3 is completed, the document is discharged to a discharge tray 10 through a document conveying path (d) on the platen and a document discharge path (nu) shown in FIG.

On the right side of the ADF 2, as shown in FIG.
An openable manual document tray 14 is provided so that the set document P (single document) can be fed to the platen 3 through a manual feed path.

(Description of Roller Arrangement) Original Conveying Path (A)
Is a conveyance path in which the document separated by the separation unit is conveyed downstream by the separation feeding roller 8. A first feeding roller 16 is provided between the document feeding paths (a) and (b) to restrain the documents sent from the separation units 6 and 8 and to skew the documents by the separation units. Preventing.

The separation / conveyance roller 8 is provided with a one-way mechanism to reduce the conveyance load when a document is pulled out of the separation section by the first feeding roller 16.

A second feeding roller 9 is provided at the junction of the document conveying paths (a), (b) and (c) and the document reversing path (g). A loop is formed in the arrived sheet document P to prevent skew of the sheet document P. A first reversing roller 17 and a second reversing roller 18 are provided in the reversing feeding path (H), (F), and (R).
The document P is transported along a loop-shaped reversal path.

On the right side of the ADF 2, a manual feed roller 1 is provided.
The document feeder 3 feeds a document set on the manual document tray 14 from right to left. A manual feed registration roller 11 is provided between the manual feed roller 13 and the platen 3 to form a loop on a manually fed document to prevent skew.

Further, the manual registration roller 11 relays the discharge of the original from the platen 3. A discharge roller 12 is provided in the document discharge path (N), and discharges the discharged document P to the discharge tray 10.

(Explanation of the flapper in the path) FIG. 4 shows the position of the flapper on the transport path.

A reversing sheet flapper 22 is provided downstream of the second feeding roller 9 in the conveying direction, and switches between a document feeding path (C) and a reversing feeding path (H). When the original P is transported to the reverse feeding path (H), (F), and (L), the original P is located at the solid line position in the figure. Swing to the dashed line position.

A reversing flapper 23 is provided downstream of the second reversing roller 18 in the transport direction, and switches between a reversing feeding path (i) and a document reversing path (g). When the original P conveyed from the original feeding path (b) or the reverse feeding path (h) is turned upside down, the reversing flapper 23 is located at the solid line position in FIG. (E), when reversing through the reversing feed path (f) and the document reversing path (g), swing to the dashed line position in the figure.

A one-way flapper 24 (to which a mylar or the like is affixed) is provided at the junction of the reversing feed path (h) and the document supply / discharge path (e) near the upstream of the first reversing roller 17. And serves as a guide when the document P is transported from the reverse feeding path (h) to the reverse feeding path (f).
The original P is fed from the reverse feeding path (g) (f) to the original feeding / discharging path (e).
When the document P is conveyed to the platen 3, the document P is prevented from entering the reverse feeding path (h) in the reverse direction.

On the platen 3 side of the reversing supply / discharge path (e), there is provided a supply / discharge flapper 25 that moves in conjunction with the reversal sheet supply flapper 22.
Is conveyed at the solid line position in the figure to prevent the leading end of the document P entering the platen 3 from colliding with the end of the platen 3. When the document P is conveyed from the platen 3 to the document supply / discharge path (e), the document P is swung to the position indicated by the dashed line in the figure so that the document from the platen 3 can be scooped.

A paper discharge flapper 26 is provided between the right end of the platen 3 and the manual registration roller 11, and when the document P is transported from the manual transport path (R) to the platen 3, it is at the position indicated by the solid line in FIG. This prevents the leading edge of the document P entering the platen 3 from colliding with the end of the platen 3.
When the document P is discharged from the platen 3 to the document discharge path (nu), the document P is swung to a dashed line position in the figure so that the document from the platen 3 can be scooped. Document ejection path (nu)
A manual flapper 27 in one direction is provided at a confluence of the manual feed path and the manual feed path to prevent the document from entering the manual feed path when the document P is discharged from the platen 3. .

A manual shutter 28 is provided near the downstream of the manual paper feed roller 13 in the transport direction, and the manual document set on the manual document tray 14 during the discharge of the copied document P enters the manual registration roller. To prevent At this time, the conveying force is set low so that the manual paper feed roller 13 and the document slip.

(Sensor Arrangement in Path) A separation sensor 30, which is a transmission type optical sensor, is provided between the separation conveyance roller 8 and the first feeding roller 16, and the separation conveyance roller 8 conveys the separation sensor 30. The original P is detected. Also, the separation sensor 3
A skew detection sensor 31, which is also a transmission type optical sensor, is provided at the same position in the transport direction as 0 and at a predetermined distance in the thrust direction, and has been fed together with the separation sensor 30. The amount of skew of the document can be detected.

In the vicinity of the downstream of the first feeding roller 16, there is provided a mixed-load detecting sensor 32 for detecting the document P by moving the flag. It is possible to detect that a document is set on the document tray 4.

In the vicinity of the upstream of the second feed roller 9, a paper feed sensor 35, which is a transmission type optical sensor, is provided. The original feed paths (a), (b), and (c) and the original reversing path (G) The front end and the rear end of the document P that has passed through any of the transport paths are detected. A registration sensor 39, which is also a transmission type optical sensor, is provided downstream of the feed roller 9, and controls the stop position of the document P by detecting the rear end of the document P.

A reversing sensor 50, which is a transmission type optical sensor, is provided in the reversing conveyance path (e), and detects the document P discharged from the platen 3 or the document P entering the platen 3. . A reversing detection sensor 33 for detecting the document P by moving the flag is provided in the reversing feeding path (R), and detects that the document P is led to the reversing feeding path (R) by switching the reversing flapper. ing.

A manual feed registration sensor 34, which is a transmission type optical sensor, is provided near the downstream of the manual feed registration roller 11 in the sheet discharging direction. Drainage route (nu)
The original P discharged to the printer is detected. Manual feed roller 13
A manual document detection sensor 60 for detecting a document P by moving a flag is provided on the side of the manual document tray 14 to detect that a document is set on the manual document tray 14.

(Description of Driving System) Next, a driving system of the document feeder 2 of the present invention will be described with reference to FIG.

FIG. 4 is a drive system diagram showing motors and solenoids for driving each transport roller and flapper.

Reference numeral 100 denotes a separation motor. In this embodiment, a DC brush motor controlled by PLL is used. A clock plate 100a composed of a plurality of slits is provided on the motor shaft of the separation motor 100, and the separation clock sensor 1 which is a transmission type optical sensor is provided.
When the separation motor 100 rotates by 00b, a clock pulse proportional to the motor rotation speed is generated.

The separation motor 100 drives the separation / conveyance roller 8 and the separation belt 6, which are separation sections, in the direction of the arrow in the figure. Further, the drive is transmitted to the paper feed roller 5 via the separation clutch 106. Reference numeral 101 denotes a transport motor that can be rotated forward and backward. In this embodiment, a stepping motor is used. The transport motor 101 drives the second feeding roller 9, the first reversing roller 17, and the second reversing roller 18.

On the driven roller shaft of the second feeding roller 9,
A clock plate 101a including a plurality of slits is provided, and a clock pulse is generated when the transport motor 101 is rotated by the slit and an inverted clock sensor 101b which is a transmission type optical sensor. If a slip occurs while the document P is being conveyed by the second feeding roller 9, the slip amount can be measured from the number of clock pulses and the number of drive clocks of the conveyance motor 101.

Reference numeral 102 denotes a forward / reverse rotatable belt motor. In this embodiment, a stepping motor is used.
The belt motor 102 drives the driving roller 36 that drives the wide belt 7, and further transmits the rotation of the driving roller 36 to the turn roller 37 by the wide belt 7. The drive is transmitted from the turn roller 37 to the manual registration roller 11 so that the transport speed of the document on the platen 3 is equal to the transport speed of the manual registration roller 11.

Reference numeral 103 denotes a reciprocating swing motor. In this embodiment, a stepping motor is used. The swing motor 103 drives a lifting arm 53 of a paper feed roller.

Reference numeral 104 denotes a paper discharge motor. In this embodiment, an FG servo control type DC motor is used. A clock plate 104a composed of a plurality of slits is provided on the motor shaft of the discharge motor 104. When the discharge motor 104 is rotated by the slit and the discharge clock sensor 104b, which is a transmission-type optical sensor, the motor is driven by the motor. A clock pulse is generated in proportion to the rotation speed.

The discharge motor 104 outputs the discharge rollers 12,
The drive is transmitted to the manual feed roller 13. 105
Is a stopper solenoid which drives a stopper 21 at the paper feed end of the document tray 4. When the stopper 21 is off, it is at the position indicated by the solid line in the figure, and when it is on, it swings to the position indicated by the chain line in the figure.

Reference numeral 106 denotes a separation clutch, which transmits the drive of the separation motor 100 to the sheet feeding roller 5, the separation belt 6, and the separation and conveyance roller 8. Reference numeral 107 denotes a path switching solenoid that drives the reverse sheet feeding flapper 22 and the supply / discharge flapper 25. When the solenoid is off, the reversing sheet flapper 22 and the supply / discharge flapper 25 are respectively at the solid line positions in the figure. When the solenoid is on, the reversing sheet flapper 22 and the supply / discharge flapper 25 are respectively It swings to the dashed line position in the figure.

Reference numeral 108 denotes a reverse flapper solenoid,
The reversing flapper 23 is driven. When the solenoid is off, the reversing flapper 23 is at the position indicated by the solid line in the figure, and when turned on, swings to the position indicated by the chain line in the figure. A discharge flapper solenoid 109 drives the discharge flapper 26 and the manual feed shutter 28. When the solenoid is off, the paper discharge flapper 26 and the manual feed shutter 28 are at the positions indicated by chain lines in the figure, and when they are on, swing to the solid line position in the figure.

(Explanation of Reading Position) FIG. 11 is a view showing the reading position of the original on the platen 3, and R1, R2, R3 in the drawing depends on the original transport mode and the original size to be transported.
Take the position. The reading position R1 is a reading position in the double-sided document mode, and an image of a document placed with its document edge aligned with this position is read by the scanner of the copier body 1 (fixed reading mode). The reading position R2 is a reading position of a half-size document in the single-sided document mode. At this position, the scanner of the copying machine main body 1 is fixed, and an image is read while the document is being conveyed (flow reading mode). The reading position R3 is a reading position of a large-size original in the one-sided original mode, and a reading position of a half-size original when the half-size original is vertically fed. Reading is performed (flow reading mode).

In FIG. 11, L1 is the second feed roller 9
, The distance from the nip point of the second feed roller 9 to R2, and L3 the distance from the nip point of the second feed roller 9 to R3.

L4 shown in FIG. 6 indicates a distance from the first image destination R1 to a stop position for standby of a half-size document placed on the left side of the platen 3, and L5 indicates a document stopped at the standby position. L6 is the distance between the trailing edge of the preceding document and the trailing edge of the succeeding document (paper distance), L7 is the distance between the first image source R1 and the manual feed registration roller 1
Indicates the distance to 1.

The length of the half-size document in the transport direction is Lp
h, the stop position of the half-size document is controlled such that L7 <[L4 + 2 × L6 + Lph] L2> [L5-Lph], so that Pn, Pn on the platen 3 as shown in FIG.
Even when -1 is stopped, the trailing end of the preceding document Pn-2 passes through the nip of the manual feed registration roller 11, and the trailing end of the document Pn waiting for image formation is the second feeding roller 9. Get out of the nip.

Next, the operation of the document feeder will be described.

(Explanation of Separation Operation) When the original set sensor 40 detects the original bundle on the original tray 4, the pre-separation operation is started, and the paper feed roller 5 descends to land on the original bundle. In the following description, the originals stacked on the original tray 4 will be referred to as an original P1, an original P2, and an original P in order from the top.
3 and so on. When the order of the originals is not specified, the original is set as the original P.

When copy conditions are input on the operation unit of the copying machine and the start key is pressed, the original size is detected by a sensor on the platen. Further, the stopper 21
Is sucked by the SL to release the path of the sheet original bundle, and the original bundle is fed by the paper feed roller 5 and advances downstream from the original P1, which is the uppermost sheet.

A separation conveyance roller 8 and a separation belt 6 which constitute a separation section are disposed downstream of the stopper 21. One sheet of the document P, which rotates in the direction of the arrow and advances from the document tray 4, is provided. Each time, it is separated and transported further downstream. The document P that has passed through the separation unit is separated by the separation sensor 30,
After skew detection is performed by the skew sensor 31, the skew is conveyed by the first feed roller 16.

When the original is conveyed by the first feed roller 16, the paper feed roller 5 is raised, then the separation clutch 106 is turned off, and the driving of the separation belt 6 and the separation conveyance roller 8 is cut off and stopped. . Since the separation / conveyance roller 8 is constituted by a one-way roller, the separation / conveyance roller 8 rotates (rotates) following the movement of the document P being conveyed. The document P is conveyed only by the first feeding roller 16 and is hit against the stopped second feeding roller 9 to perform a known skew feeding.

When the skew feeding is completed, the first feed roller 16
And the second feeding roller 9 start rotating at the same time, but the two rollers are synchronously controlled so that their transport speeds coincide. The subsequent operation differs depending on the document transport mode, and will be described separately for each mode.

(Half-size one-sided original transport mode) FIG. 1
3 and FIG. 14 are diagrams schematically illustrating the flow of a document in the single-sided document transport mode.

When the original transport mode is the one-sided original transport mode, the path switching solenoid 107 is turned off, so that the transport path is on the original feed path (c), and the preceding original P 1 is placed on the platen 3. I will enter. Previous manuscript P1
Before the sheet enters the platen 3, the conveying speed of the wide belt 7 is controlled to match the speed of the second feeding roller 9.

When the trailing end of the preceding document P1 has passed the nip point of the sheet feeding roller 5, the feeding roller 5 descends again to prepare for the operation of feeding the succeeding document P2.

Further, when the trailing end of the preceding document P1 passes through the nip point of the first sheet feeding roller 5, the separation clutch 106 is turned on, and the sheet feeding roller 5 starts feeding the succeeding document P2. This state is shown in FIG.

When the trailing edge of the preceding document P1 has passed through the nip of the second feeding roller 9, the second conveying roller 9 is stopped. The subsequent document P2 is rapidly accelerated after the start of sheet feeding by the sheet feeding roller 5, and is controlled so as to reach the sheet feeding sensor 35 when the second transport roller 9 stops. Is turned on, control for skew removal is performed in the same manner as in the case of the preceding document P1.

At this time, the preceding document P1 has entered the transport path (d) on the platen 3 and is independently transported by the wide belt 7, and once stopped a predetermined distance after the trailing edge has passed through the paper feed sensor 35, stops once. (FIG. 13- (b)).
At this time, the leading edge of the document P1 and the second image reading position R2
Is controlled to be L5. Further, a distance L8 between the rear end of the document P1 and the nip point of the second feed roller 9
Is the distance expressed as L8 = L2-L5-conveyed document size L2: distance from the second image destination position R2 to the second feeding roller 9, and this value (L8) is configured to be positive. (The rear end of the original P1 has passed the nip of the second feed roller). Simultaneously with the stop, the transport completion signal 120 is output to the copying machine main body, and the control waits for the input of the transport start signal 121. The state at this time is shown in FIG.
This is shown in FIG.

When the conveyance start signal 121 from the copying machine main body is received and the skew feeding control of the succeeding document P2 is completed, the wide belt 7 is started to convey the preceding document P1 at the image forming speed.

When the distance between the trailing edge of the preceding document P1 and the leading edge of the succeeding document P2 (hereinafter referred to as the sheet distance) becomes a predetermined distance, the second feeding roller 9 is started to form an image similarly to the preceding document P1. Convey at speed. When the conveying speeds of the wide belt 7 and the second feeding roller 9 match, the activation and acceleration of the second feeding roller 9 are controlled so that the above-mentioned sheet distance becomes L6. When the preceding original P1 reaches the second image destination position R2, an image destination reaching signal 122 is output. The copier body 1 receives this and starts reading an image of the preceding original P1.

FIG. 13C shows the state of the document P1 after the image reading is completed, and the document P1 is stopped after being conveyed a predetermined distance (L9) after the reading is completed. At this time, the succeeding document P2 is stopped at a distance L5 from the second image destination position R2, and the subsequent document P3 is
The second feeding roller 9 stands by while maintaining a loop for skew feeding.

In this state, when the conveyance start signal 120 is input from the copying machine main body 1, an image for the original P2 is formed. FIG. 14A shows a state in which an image of the original P2 is being read.
The original P1 is conveyed by a wide belt 7, a manual registration roller 11, and a paper discharge roller 12. At this time, the transport speeds of the wide belt 7 and the manual registration roller 11 are configured to be equal, and the transport speed of the paper discharge roller 12 is controlled to be equal to or slightly faster than these speeds.

FIG. 14B shows the state when the reading of the subsequent document P2 is completed. Since the wide belt 7 stops after the reading is completed, the subsequent documents P2 and P3 stop on the platen 3. ing. Since the trailing end of the preceding document P1 has already passed through the nip of the manual registration roller 11, it is conveyed independently by the paper discharge roller 12 and discharged to the paper discharge tray 10.

(Large-size one-sided original transport mode) FIG.
5 and 16 are diagrams schematically illustrating the flow of a document in the large-size one-sided document conveyance mode.

As in the case of the small-size one-sided original conveying mode, the path switching solenoid 107 is controlled to be off, so that the conveying path is on the original feeding path (C) side, and the preceding original P1 is the platen 3 When the trailing end of the preceding document P1 has passed the nip point of the sheet feeding roller 5, the feeding roller 5 descends again to prepare for the sheet feeding operation of the succeeding document P2.

Further, when the trailing end of the preceding document P1 passes through the nip point of the first sheet feeding roller 5, the separation clutch 106 is turned on, and the sheet feeding roller 5 starts feeding the succeeding document P2. This state is shown in FIG. When the rear end of the preceding document P1 has passed through the nip of the second feeding roller 9, the second conveying roller 9 is stopped. The subsequent document P2 is rapidly accelerated after the start of sheet feeding by the sheet feeding roller 5, and is controlled so as to reach the sheet feeding sensor 35 when the second transport roller 9 stops.
Is turned on, control for skew removal is performed in the same manner as in the case of the preceding document P1.

At this time, the preceding original P1 is in the transport path (d) on the platen 3, is independently transported by the wide belt 7, and stops once when its rear end has advanced a predetermined distance after passing through the paper feed sensor 35.

At this time, the distance between the leading edge of the document P1 and the third image reading position R3 is L5 as in the control of the half-size document. Also, the rear end of the document P1 and the third feeding roller 9
L10 = L3−L5−conveyed document size L3: distance from the third image destination position R3 to the second feeding roller 9, and the value (L10) becomes positive. (The rear end of the document P1 has passed the nip of the second feeding roller). At the same time as the stop, the transport completion signal 120 is output to the copying machine main body, and the process waits for the input of the transport start signal 121. The state at this time is shown in FIG.
(B).

When the conveyance start signal 121 from the copying machine main body is received and the skew feeding control of the succeeding original P2 is completed, the wide belt 7 is started to convey the preceding original P1 at the image forming speed. When the preceding original P1 reaches the third image destination position R3, an image destination reaching signal 122 is output. The copier body 1 receives this and starts reading an image of the preceding original P1.

When the distance between the trailing edge of the preceding document P1 and the leading edge of the succeeding document P2 (hereinafter referred to as the sheet distance) has reached a predetermined distance, the second feed roller 9 is started, and the image forming speed is the same as that of the preceding document P1. To be transported. At this time, the wide belt 7 and the second
The activation and acceleration of the second feed roller 9 are controlled so that the above-mentioned sheet distance L11 at the time when the feed speeds of the feed rollers 9 match is achieved. This state is shown in FIG.

FIG. 16B shows a state after the image reading of the original P1 is completed. The subsequent original P2 is stopped on the platen 3. The inter-sheet distance L11 is the following document P2
Since the distance is set to be larger than the distance from the leading edge to the nip point of the manual registration roller 11, when the succeeding document P2 is stopped, the rear end of the preceding document P1 passes through the nip point of the manual registration roller 11. Manuscript P
1 is independently conveyed and discharged by the discharge roller 12.

(Transport of Half-size Double-sided Document) FIGS.
FIG. 20 is a diagram schematically illustrating the flow of a document during double-sided document conveyance. The transport speeds of the second feeding roller 9 and the wide belt 7 are controlled to be constant except in special cases.

When the original transport mode is the duplex original transport mode, first, the reverse sheet feed flapper 22 and the reverse flapper 23
Is at the position of the solid line in FIG. 3, and the original P1 is in the reverse feeding path (h).
(F) It is led to the side of (li) (FIG. 17a).

When the rear end of the original P1 passes through the one-way flapper 24, the rollers 17 and 18 are rotated in the reverse direction to rotate the original P1.
In the reverse direction. Since the supply / discharge flapper 25 is located at the position indicated by the solid line in FIG.
It is guided to the upper transport path (d) (FIG. 17b).

The wide belt 7 is stopped when the original is conveyed a predetermined distance after the rear end of the original in the conveying direction is detected by the reversing sensor 50, and the original P1 is placed at the image position R1 in the fixed reading mode (see FIG. 18a). The second surface is read by the scanner.

Since the path switching solenoid 107 is turned off around the time when the placement of the document P1 is completed, the reverse sheet feeding flapper 2 is turned off.
2. The supply / discharge flapper 25 swings to the hatched position in FIG.
When the scanning of the second surface of the document P1 is completed by the scanner of the copying machine body 1, the wide belt 7 rotates in the reverse direction, and the document is conveyed to the document supply / discharge path (e). Since the reversing flapper 23 has been moved to the position indicated by the chain line in FIG. 3 simultaneously with the reverse rotation of the wide belt 7, the document is guided to the document reversing path (g) (FIG. 18b).

When the document is conveyed a predetermined distance after the leading edge of the document is detected by the reversing sensor 50, the rotation of the wide belt 7 temporarily stops and then changes from reverse rotation to normal rotation. When the leading end of the inverted document P1 approaches the transport path (d) on the platen, control is performed so that the transport speeds of the second feeding roller 9 and the wide belt 7 match. When the trailing end of the preceding document P1 has passed the nip point of the second feeding roller 9, the second feeding roller 9 stops and waits for the arrival of the following document P2.

The preceding original P1 is independently conveyed by the wide belt 7. When the original is conveyed a predetermined distance after the trailing end of the original is detected by the paper feed sensor 35, the wide belt stops and the fixed original reading mode is set. It is placed at the destination of the image. The first surface is read by the scanner.

Further, before and after the trailing edge of the preceding document is detected by the paper feed sensor 35, the separating operation of the succeeding document P2 is started.
The well-known skew feeding is performed by the second feeding roller 9.

During the scanning of the first side of the original P1 by the scanner of the copying machine body 1, the inversion operation of the succeeding original P2 is completed,
The vicinity of the leading end of the succeeding document is on standby while being nipped by the first reversing roller 17 (FIG. 19A).

When the scanning of the first surface of the preceding document P1 is completed, the reverse rotation of the first reversing roller 17 and the second reversing roller 18 and the normal rotation of the wide belt 7 are started, and the preceding document P1 and the following document are placed on the platen 3. P2 is placed a predetermined distance (L12) apart (FIG. 19b).

When the scanning of the second side of the original P2 by the scanner of the copier body 1 is completed, the reversing operation of the succeeding original P2 is started as in the case of the preceding original P1, and the succeeding original P2 and the preceding original P1 are inverted. Although the paper is conveyed in the direction of the feeding path (e), the rotation of the belt is temporarily stopped when the preceding document P1 is on the conveyance path (d) on the platen upper 3 because the sheet interval L12 is set to an appropriate value. Thereafter, the rotation direction of the wide belt 7 is switched, and the document P1 and the document P2 are conveyed again in the direction of the paper discharge roller 12, stopped in the state shown in FIG. 20A, and scanning of the first surface of the document P2 is started. . Original P at this time
The distance between the sheet P1 and the document P2 is L13 (it can be controlled to be L12). At this time, the subsequent document P3 is in a state of being nipped by the first reversing roller 17 as in the case of the document P2 shown in FIG.

When the scanning of the first side of the document P2 is completed, the reverse rotation of the first reversing roller 17 and the second reversing roller 18, the normal rotation of the wide belt 7, and the rotation of the paper discharge roller 12 are started, and the subsequent document P3, Documents P2 and P for which image reading has been completed
1 are conveyed simultaneously.

When the wide belt 7 stops and the placement of the second surface of the succeeding document P3 is completed, the rear end of the preceding document P1 has passed through the nip of the manual registration roller 11, and the preceding document P1 is The sheet 12 is conveyed alone and discharged to the sheet discharge tray 10 (FIG. 20B). This is achieved with L13.

The above operation is continuously performed, and the final document Pn
When the scanning of the first surface is completed, the last original Pn and the last front original Pn-1 are arranged on the platen 3 and are discharged at one time by the continuous operation of the wide belt 7.

(Transport of Full-Size Double-sided Original) FIGS. 21 to 24 are diagrams schematically showing the flow of the original when the full-size double-sided original is transported. The second feed roller 9 and the wide belt 7
Is controlled to be constant speed except in special cases.

When the original transport mode is the duplex original transport mode, first, the reversing sheet flapper 22 and the reversing flapper 23
Is at the position of the solid line in FIG. 3, and as shown in FIG.
The document P is guided to the reversing feed path (H), (F), and (R).

When the rear end of the document has passed the one-way flapper 24, the rollers 17 and 18 are rotated in the reverse direction to convey the document in the reverse direction.

Since the supply / discharge flapper 25 is located at the position indicated by the solid line in FIG. 4, the inverted document is guided to the transport path (d) on the platen 3. This state is shown in FIG.

When the wide belt 7 has been conveyed a predetermined distance after the rear end of the original in the conveying direction is detected by the reversing sensor 50, the wide belt 7 stops, and as shown in FIG. The original is placed.

Since the path switching solenoid 107 is turned off around the time when the document placement is completed, the reverse sheet feeding flapper 22 is turned off.
The supply / discharge flapper 25 swings to the position indicated by the chain line in FIG. When the scanning of the second side of the original is completed by the scanner of the copying machine main body 1, the wide belt 7 rotates in the reverse direction, and the original is fed to the original feeding / ejecting path (e).
The document is guided to the document reversing path (g) because the reversing flapper 23 is moved to the position indicated by the chain line in FIG. 4 simultaneously with the reverse rotation of the wide belt 7. This state is shown in FIG.
(B).

When the original is conveyed a predetermined distance after the leading edge of the original is detected by the reversing sensor 50, the rotation of the wide belt 7 temporarily stops and then changes from reverse rotation to normal rotation. When the leading edge of the inverted document approaches the transport path (d) on the platen, the control is performed so that the transport speeds of the second feeding roller 9 and the wide belt 7 match.

When the trailing end of the preceding document has passed the nip point of the second feeding roller 9, the second feeding roller 9 stops and waits for the arrival of the following document.

The preceding original P1 is independently conveyed by the wide belt 7. When the original is conveyed a predetermined distance after the trailing end of the original is detected by the paper feed sensor 35, the wide belt stops and the fixed original reading mode is set. The document is placed at the stop position R1.

Further, before and after the trailing edge of the preceding document is detected by the paper feed sensor 35, the separating operation of the succeeding document P2 is started.
A known skew removal is performed by the stopped second feeding roller,
As shown in FIG. 23 (a), the reverse feeding path (h) (f)
The document P2 is guided to (i).

During the scanning of the first side by the scanner of the copying machine body 1, the reversing operation of the succeeding document P2 is completed in the same manner as in the case of the preceding document P1, and as shown in FIG. The vicinity stands by while being nipped by the first reversing roller 17. At this time, the interval between the preceding original P1 and the waiting succeeding original P2 is controlled to be L14.

When the scanning of the first side of the preceding document is completed, the reverse rotation of the first reversing roller 17 and the second reversing roller 18 and the normal rotation of the wide belt 7 are simultaneously started, and as shown in FIG.
The value of L14 is determined so that when the succeeding document P2 is placed on the platen 3, the trailing edge of the preceding document passes through the nip of the manual registration roller 11.

Thereafter, the same operation is continued up to the final document Pn.

(Document Conveyance When Copying a Manual Document) FIG. 2
5, FIG. 26 is a diagram showing the flow of a document when a manual document is conveyed.

When the manual document detection sensor 60 detects that a document is set, the manual flapper 27 and the manual shutter 28 move to the solid line positions in FIG. After skew feeding is performed by the stopped manual feed registration roller 11, the document stops when the leading edge of the document arrives at the first image destination position R1 of the platen 3. At this time, the manual flapper 27 and the manual shutter 28 return to the positions indicated by the dashed lines in FIG. 4, and the next original can be set.

After the scanning by the scanner 204 of the copying machine is completed, the original P1 is discharged toward the paper discharge roller 12 by the reverse rotation of the belt 7. When the paper discharge roller 12 rotates, the manual paper feed roller 13 also rotates. However, since the front end of the document P2 is regulated by the manual paper shutter 28, the manual paper feed roller 13 slips and does not move forward. (FIG. 26A).

The trailing end of the document P1 is the manual feed registration sensor 3.
4, the manual feed registration roller 11 stops, and the manual feed flapper 27 and the manual feed shutter 28
To the position indicated by the solid line.

Thereafter, the document P2 is conveyed to the manual feed registration roller 11 by the roller 13, and is placed on the platen 3 in the same manner as P1 after the above-described skew feeding is completed.

(Description of Block of Control Circuit) FIG. 27 is a block diagram showing a circuit configuration of a control device according to this embodiment. The control circuit is mainly composed of a microprocessor (CPU) 201. Drive circuits of various loads and sensor signals are connected to the input / output ports.

The control circuit has a RAM backed up by a battery (not shown) and a ROM storing control sequence software. Reference numeral 202 denotes a communication IC for controlling data communication with the copying machine main body.

In FIG. 27, separation motor 100 (DC
Brush motor) includes a driver 203 and a controller 203
a is controlled by the controller 203a.
, A reference clock serving as a reference for the motor rotation speed, an on / off signal, and the like are input from the CPU 201.

Transport motor 101 (stepping motor)
Are driven by a stepping motor driver 204. Similarly, the belt motor 102 (stepping motor) is also driven at a constant current by the stepping motor driver 205. Each driver receives a phase excitation signal from the CPU 201 and a motor current control signal.

The swing motor 103 (stepping motor)
Is driven by a driver 206 at a constant voltage, and the discharge motor 104 (DC brush motor) is driven and controlled by a driver 207 and an FG servo controller 104a.

The motors 100 to 104 have encoders 100a to 104a and detecting means 100b to 104, respectively, as means for detecting the rotational speed of the motors.
b. Further, the shutter solenoid 105 is driven by a driver 208. Similarly, the separation clutch 106 is a driver 209, the path switching solenoid 107 is a driver 210, and the reversing flapper solenoid 10
The driver 8 is driven by a driver 211, and the paper discharge flapper solenoid is driven by a driver 212.

The drivers 203 to 212 are all C
By the signal connected to the input / output port of the PU 201,
Its operation is controlled. Furthermore, a separation sensor 30, a skew detection sensor 31, a mixed loading detection sensor 32, a reversal detection sensor 33, a manual feed registration sensor 34, a paper feed sensor 35, a reversal sensor 36, a manual document detection sensor 37,
Various sensors such as a registration sensor 39, a document set sensor 40, a document trailing edge detection sensor 41, a final document detection sensor 43, a paper width detection sensor 44, a paper feed roller home sensor 45, and a swing position sensor 46 are connected to input ports of the CPU 201. Connected and used to monitor the behavior of the document and the behavior of the movable load in the device.

(Copier Main Body Feeding Control for Mixed Originals) Next, the copier main body feeding control for mixed originals will be described with reference to FIG.

In this case, as shown in FIG.
Two A4 sheets, A3-1 + A3-2 + A in order from the top sheet
The case where 4-1 + A4-2 are simultaneously set on the document tray 4 will be described.

First, it is determined whether or not the copying machine is in the mixed mode (step S101). Whether or not to set the mixed mode is input by the user at the copier operation unit. In the mixed mode, the first original (A3-1) is fed to the platen at the reading position of the copying machine body 1, and then the size of the original fed to the platen is checked (step S102). A cassette is selected (step S10)
3).

Next, it is determined whether the trailing edge detection sensor 41 on the document tray is ON or OFF (step S104).
Since 2 is on the tray, the trailing edge detection sensor 41 is determined to be ON, and the process returns to check the size of the fed document (step S102).

Next, after A3-2 is fed to the platen, the trailing edge detection sensor 41 on the tray is turned off, so that the next original A4-1 is fed to the platen and a size check is performed (step S105). , After selecting the cassette (step S1
06), a communication IC for controlling data communication with the copying machine body
A signal for permitting the preceding paper feeding (during image formation) is transmitted to the copying machine main body via 202 (step S107).

After the lowermost sheet A4-2 on the tray is fed to the platen, the last original detection sensor 43 is turned off (step S108). The copier body is transmitted via the IC 202 (step S107). Here, in the non-mixed loading mode, the precedent paper feed is to advance the transfer paper by a predetermined distance from the paper feed cassette and keep it in a standby state in order to minimize the paper feed time.

On the other hand, when the mode is not the mixed mode, the size of the leading document is checked (step S110), a transfer paper feed cassette corresponding to the size of the document is selected (step S111), and continuous paper feeding is permitted (step S111). S11
2). Then, continuous paper feeding is performed until the last original detection sensor 43 is turned off. When the last original detection sensor 43 is turned off (step S113), continuous paper feeding is prohibited (step S114).

The specific operation in the non-mixed mode is as shown after the main flow in FIG. Note that, as described above, entry into the mixed loading mode is set by the user before entering the main flow of FIG.

(Main Flow) Next, the operation of this embodiment will be described with reference to the main flowchart shown in FIG.

The document set detection sensor 40 detects whether or not a document is set on the document tray 4, and the operation is started by pressing a copy key on an operation unit (not shown) of the copying machine main body (main1). At this time, the copy mode transmitted from the main body is determined (main2), and if the mode is the one-sided original mode, the process proceeds to (main3). In (main3), it is determined whether or not the document trailing edge detection sensor 41 is turned off. If the determination is affirmative, the process proceeds to (main4), and a series of copying is performed in a first flow reading mode described later. The process is executed, and the operation ends. In (main3), when a negative determination is made, the process proceeds to (main5),
A series of copy processing is executed in a second flow reading mode described later, and the operation ends. Also, in (main2),
If the determination is negative, the process proceeds to (main6), and a series of copying processes is performed in the double-sided document mode, thus ending the operation.

Here, the mode selection based on the document size is as follows.
In the present control example, the selection is restricted only by the feed direction based on the on / off of the document trailing edge detection sensor 41. However, as described above, the document width detection means provided by the paper width detection sensor 44 provided at the lower portion of the document tray 4 The mode selection may be restricted by the size of the document by a combination of the above.

A manual document set detection sensor detects whether or not a document is set on the manual document tray.
By pressing the copy key on the operation unit of the copying machine main body (not shown), the process proceeds to (main7) and (main8), and a series of copying processes is executed in the manual feed mode described later, thus ending the operation.

(First Flow Reading Mode) Next, the first flow reading mode will be described with reference to FIG.

A pickup DOWN process (to be described later) is performed to move the paper feed roller 5 onto the sheet placed on the document tray 4 (draftmd1).
A separation process (draftmd) described below to separate only
2) and a paper feed process (draftmd3) is performed. Further, a document flow reading process for reading the document image with the optical system of the copying machine main body fixed at a predetermined position is started (d
(draftmd4), and then waits for the trailing end of the document to be detected by the separation sensor 30 (draftmd5). The document set detection sensor 40 detects the break of the document bundle (draftmd6). In order to discharge the original onto the discharge tray 10, a discharge process described later is started (draftmd7), and (draftm7).
Returning to d2), the process is repeated. Also, (draftm
In d6), if the original is the final document, a paper discharge process is performed (draftmd8), and then a pickup UP process described later is performed to return the paper feed roller 5 to the upper limit position (draftmd9), and a series of processes is performed. finish.

At this time, as shown in FIG. 11, when the length of the original in the feed direction is L ′ mm, the scanner 204 of the copying machine main body 1 as shown in FIG. , L'mm or more, and is located downstream of the transport path in the transport direction (R2, R3 in FIG. 11). Also, this scanner 2
The position control of 04 may be performed by a well-known stepping motor control, or may be performed by a mechanical stopper.

(Second Flow Reading Mode) Next, the second flow reading mode will be described with reference to FIG.

A pickup DOWN process described later is performed to move the paper feed roller 5 onto the sheet placed on the document tray 4 (draft2md1). Thereafter, a separation process described later is performed to separate the uppermost document by one sheet. Processing (draft2m
d2), and a sheet feeding process (draft2md3). Further, the document flow reading process for reading the document image with the optical system of the copying machine main body fixed at a predetermined position is started (draft2md4). At the same time, since the fixed position of the optical system is near the paper discharge unit, the document is not read. In order to discharge the paper onto the paper discharge tray 10, a paper discharge process to be described later is activated (draft).
t2md5). Thereafter, the process waits until the trailing edge of the document is detected by the separation sensor 30 (draft2md6), and the document set detection sensor 40 detects the break of the document bundle (draft2md7).
Returning to (draft2md2), the process is repeated. If the original is the last original in (draft2md7), the pickup UP process described later is performed to return the sheet feeding roller 5 to the upper limit position (draft2md8), and the series of processes is ended.

At this time, the scanner 204 of the copying machine main body 1 as shown in FIG. 1 is at the position of R3 shown in FIG.

(Duplex Document Mode) Next, the duplex document mode will be described with reference to FIG.

A pickup DOWN process (to be described later) is performed to move the paper feed roller 5 onto the paper placed on the document tray 4 (doublel), and thereafter, a separation process to be described later is performed to separate the uppermost document by one sheet. (Doubled
Perform 2). Further, in order to turn the separated document upside down so that the second side of the document comes into contact with the platen and is placed at the left end on the platen, a pre-reversal process (doubled
Perform 3). Thereafter, an optical system moving original reading process for reading the original image while moving the optical system of the copying machine main body is performed (doubled 4), and when it is completed,
Reverse processing is performed to reverse the front and back surfaces again (double
md5), an optical system moving original reading process is performed (do
ubled6), the reading of the original image on the first side is also completed. While the reading process is being performed, the document set detection sensor 40 detects the break of the document bundle (dou).
If the original is not the last original, a discharge process described below is started to discharge the original to the discharge tray 10 (double8), and the process returns to (doubleble2) to repeat the process. Further, in (doubled7), if the original is the last document, a paper discharging process is performed (doubled9), and then a pickup UP process described later is performed to return the paper feed roller 5 to the upper limit position (dubled7).
oublem10), and a series of processing ends.

(Manual Insertion Mode) Next, the manual insertion mode will be described with reference to FIG.

A manual paper feeding process is performed to convey the original set in the manual paper feeding unit onto the platen 3 of the copying machine body (manualmd1). Thereafter, an optical system moving original reading process for reading the original image while moving the optical system of the copying machine body is performed (manualmd2). When the reading is completed, the paper discharging process is performed to discharge the original to the paper output tray 10. It starts up (manualmd3), and then waits until the trailing edge of the document is detected by the manual feed registration sensor (ma
nualmd4), the presence or absence of the next document is detected by the manual document set detection sensor.
Return to (manualmd5) and repeat the process. If there is no next original, a manual paper ejection process is performed, and the series of processes ends.

(Pickup DOWN Processing) Next, FIG.
4, the pickup DOWN process will be described.

The paper feed roller 5 is connected to the paper feed roller home sensor 4
The swing motor 103 is driven (pickupdwn1) to lower the document bundle P placed on the document tray from the position shown in FIG. The arm 2 is lowered. After the feed roller home sensor 45 is turned off, it is confirmed that the feed roller has been lowered (pickupdwn2), and then the first swing position sensor 46 and the second swing position sensor 47 are turned on, so that the feed roller 5 is turned off. When it is detected that has fallen on the paper surface (pickupdwn3), the drive of the swing motor 103 is stopped (pickupdwn4).

(Pickup UP Process) Next, the pickup UP process will be described with reference to FIG.

The rocking motor 103 is driven to raise the paper feed roller 5 to the position shown in FIG. 5 (pickup).
1). When the paper feed roller home sensor 45 is turned on to detect that it has reached the upper limit position (pickup
2) Stop driving the swing motor 103 (pickup)
up3). The rotation direction of the swing motor 103 at this time is opposite to that during the pickup DOWN processing.

(Separation Processing) Next, separation processing will be described with reference to FIG.

The separation motor 100 is turned on (sepa
1) By rotating the paper feed roller, the separation belt 6, the separation / conveyance roller 8, and the first feeding roller 16 that are falling on the document bundle P, only the topmost document of the document bundle P is reduced to one sheet. The sheet is separated and transported in the sheet path (a). afterwards,
When the leading edge of the document is detected by turning on the separation sensor 30 (sepa2), a loop is formed by abutting the leading edge of the document against the second feeding roller 9 so that the separating process is completed within a predetermined time range. From the remaining transport distance up to and the elapsed time until the separation sensor 30 is turned on.
Speed control of 0 is performed (sepa3). Thereafter, when the leading edge of the document is detected by turning on the paper feed sensor 35 (step
a4) Start a separation loop counter counting by a clock signal input from the separation clock (se)
pa5), after the end of the set count (sepa6), the separation motor 100 is turned off (sepa7), so that the leading end of the original is abutted against the nip portion of the second feeding roller 9, and a predetermined amount of loop is formed. Stop in state. Thus, even when skew occurs during separation, the skew is corrected.

(Sheet Feeding Process) Next, the sheet feeding process will be described with reference to FIG.

As shown by the solid line in FIG. 4, the reversing sheet feeding flapper 22 is normally biased so that the original is conveyed to the sheet path (H) when the path switching solenoid 107 is off. The switching solenoid 107 is turned on to switch the reverse sheet feeding flapper 22 to the position shown by the chain line in FIG. 4 (entl). Further, the separation motor 100 and the conveyance motor 101 are used to convey the document, whose tip is abutted against the second feeding roller 9 and nipped by the first feeding roller 16, to the sheet paths (c) and (d). The belt motor 102 is turned on (ent2), and the first feed roller 1 is turned on.
6, the second feeding roller 9 and the wide belt 7 are driven. At the same time, a size check counter for counting by a clock signal input from the inverted clock is started (ent3). Then, by detecting the leading edge of the document by the registration sensor 39, it is confirmed that the document has been conveyed to the sheet path (c) (ent4). Thereafter, when it is detected that the rear end of the document has passed the separation sensor 30 (ent
5) Start a separation off counter counting by a clock signal input from the separation clock (en)
t6). Then, the separation sensor 3 is moved from the first feeding roller 16 to the separation sensor 3.
When the count for the distance to 0 is completed, (ebt
7) Since the trailing end of the original is removed from the first feed roller 16, the separation motor 100 is turned off to stop driving the first feed roller 16 (ent8). Thereafter, when it is detected that the rear end of the document has passed the paper feed sensor 35 (ent
9) Stop the size check counter (en
t10) Based on the data, a size check process (ent11) shown in FIG. 42 is performed. At the same time, a registration counter counted by the belt excitation clock is started to stop the document at a predetermined position on the platen 3 (ent12). Thereafter, at the time when counting is performed for the distance L4 from the paper feed sensor 35 to the second feeding roller 9 (ent13), the conveying motor 101 is turned off (ent14), and when the above-described registration counter ends (ent15). , Belt motor 10
2 is turned off (ent16). Then, the path switching solenoid 107 is turned off (ent17).

(Pre-inversion processing) Next, the pre-inversion processing will be described with reference to FIG.

As shown by the solid line in FIG. 4, the reverse feed flapper 22 is biased so that the original is conveyed to the sheet path (h) with the path switching solenoid 107 turned off. The tip is abutted against the feed roller 9,
In order to transport the document nipped by the first feed roller 16 to the sheet path (h), the separation motor 100
When the transport motor 101 is turned on (pretrn1), the first
Feeding roller 16, second feeding roller 9, first reversing roller 1
7. The second reversing roller 18 is driven. At the same time, a size check counter for counting by a clock signal input from the inverted clock is started (pre
trn2). Then, by detecting the leading edge of the document by the registration sensor 39, it is confirmed that the document has been conveyed to the sheet path (h) (pretrn3). Thereafter, when it is detected that the rear end of the document has passed the separation sensor 30 (pret
rn4), a separation off counter that counts with a clock signal input from the separation clock is started (pretrn5). Then, when the counting for the distance from the first feed roller 16 to the separation sensor 30 is completed (pretrn6), the separation motor 100 is turned off because the rear end of the document has come off from the first feed roller 16. To stop driving the first feed roller 16 (pretrn
7). Thereafter, when the feed sensor 35 detects that the trailing edge of the document has passed (pretrn8), the size check counter is stopped (pretrn9), and the size check processing (pretn) shown in FIG.
trn10). When it is detected that the trailing edge of the document has passed through the registration sensor 39 (pretrn1
1) Start a pre-reversal counter counted by the reversal excitation clock to stop at a predetermined position where the trailing edge of the document has passed the sheet path (h) (pretrn1)
2). At this time, the reversing flapper 23 is biased so that the document is conveyed to the sheet path (re) as shown by the solid line in FIG. When the started pre-reversal counter ends (pretrn13), the transport motor 101 is turned off (pretrn14). After the motor is turned off for a predetermined time, the conveyance motor 101 is rotated in the reverse direction and the belt motor 102 is turned on (pretrn 15) to convey the document to the sheet path (e) and to detect that the leading end of the document has passed the reversing sensor 36. (Pretrn16), it is confirmed that the sheet has been conveyed to the sheet path (e). Further, when it is detected that the rear end of the document has passed the reversing sensor 36 (pret
rn17), the transport motor 101 is turned off (pret
rn18) At the same time, a pre-feed counter which is counted by the belt excitation clock to stop the original at a predetermined position on the platen is started (pretrn19).
When the started pre-feed counter ends (pretrn20), the belt motor 102 is turned off (pretrn21).

(Inversion Process) Next, the inversion process will be described with reference to FIG.

As shown by the solid line in FIG. 4, the inversion flapper 23 is in the state where the inversion flapper solenoid 108 is off.
Since the document is urged to be conveyed to the sheet path (i), the reverse flapper solenoid 108 is turned on to switch the reverse flapper 23 to the position shown by the solid line in FIG. Further, the reverse sheet feeding flapper 22 and the supply / discharge flapper 2
The path switching flapper solenoid 107 is turned on so as to switch each of the positions 5 to the positions indicated by the chain lines in FIG. 4 (tr
n1). To convey the document on the platen 3 to the sheet path (e), the belt motor 102 and the conveyance motor 101 are turned on (trn2), and the wide belt 7, the second feeding roller 9, the first reversing roller 17, and the second The reversing roller 18 is driven. When it is detected that the leading edge of the document has passed through the reversing sensor 36 (trn3), the leading edge of the document is in a sheet path (f),
When the belt motor 10 reaches a predetermined position in (g),
Start / reverse counter counted by the belt excitation clock to stop / reverse 2 (trn
4). At the time when the above-described inverted counting is completed (trn5), the belt motor 102 is turned off (trn5).
6) After turning off the motor for a predetermined time, the belt motor 10
2 is reversed (trn7). During this time, the transport motor 101
Is turned on, the first reversing roller 17, the second reversing roller 18, and the second feeding roller 9 on which the document is nipped
Is driven, so that the sheet paths (f) and (g) are conveyed. Then, by detecting that the leading edge of the document has passed through the paper feed sensor 35 (trn8), it is confirmed that the sheet path (g) has been conveyed, and when the trailing edge of the document has passed the registration sensor 39 (trn9). ), The transport motor 101 is turned off (trn10). At the same time, a reverse sheet feeding counter counted by the belt excitation clock is started to stop the document at a predetermined position on the platen (trn11). At the time when the above-described reversal sheet feeding counter ends (trn12), the belt motor 102 is turned off (trn13), the reversing flapper solenoid 108 is turned off, and the reversing flapper 23 is moved to the position shown by the solid line in FIG. Switching solenoid 107
To turn off the reversing sheet feed flapper 22 and the supply / discharge flapper 25
To the position shown by the solid line in FIG. 4 (trn14).

In (trn7), the original is pulled in the opposite direction by the first reversing roller 17 and the wide belt 7,
Since the nip force of the first reversing roller 17 is stronger, the document is conveyed following the reversing roller. However, when the original is long in the feeding direction, the first reversing roller 1 is strongly affected by the nip force between the pressing roller inside the wide belt 7 and the platen.
7 will not follow. From this point on, the belt motor 102 is stopped and the timing of reverse rotation, that is, the value of the reversal counter is controlled so as to differ depending on the length of the document in the feeding direction.

(Sheet Discharge Processing) Next, the sheet discharge processing will be described with reference to FIG.

When the discharge flapper solenoid 109 is turned off, the discharge flapper 26 is biased to a position where the tip of the flapper is lower than the platen as shown by the chain line in FIG. Seat path (d), (nu)
Belt motor 102, paper discharge motor 1
04 is turned on (ejct1), and the wide belt 7, the manual paper feed roller 13, and the paper discharge roller 12 are driven. By detecting that the leading edge of the document has passed the manual feed registration sensor 37 (ejct2), it is confirmed that the document is being conveyed along the sheet path (nu), and when the trailing edge of the document has passed the manual feed registration sensor 37 ( ejct3), the belt motor 102 is turned off (ejct4). At the same time, a paper discharge counter that counts with a clock signal input from the paper discharge clock is started (ejct5), and after the set count is completed (ejct6), the paper discharge motor 104 is turned off (ejct7), so that the document passes through the sheet path (ejct7). And passes through the paper discharge roller 12 and is discharged onto the paper discharge tray 10.

(Manual Paper Feeding Process) Next, the paper discharging process will be described with reference to FIG.

With the discharge flapper solenoid 109 turned off, the discharge flapper 26 and the manual feed shutter 28
As shown in the solid line position in FIG. 4, the leading end of the paper discharge flapper is urged to a position lower than the platen, and the manual flapper 26 is in a state where the leading end of the document set in the manual paper feed unit is abutted. is there. Therefore, the discharge flapper 109 is turned on, and the manual feed shutter 2 is moved to a position indicated by a chain line in FIG.
8. The paper discharge flapper 26 is switched (ment1). Then, the discharge motor 104 is turned on (ment2), and the manual feed roller 13 is rotated to convey the document along the sheet path. After that, the manual registration sensor 3
4 when the leading edge of the original is detected by turning on
3) Start the manual feed loop counter which is counted by the clock signal input from the paper discharge clock (m
ent4), after the end of the set count (ment5),
When the discharge motor 104 is turned off (ment 6), the leading end of the document is hit against the nip portion of the manual feed registration roller 11, and the document is stopped with a predetermined amount of loop formed.
Thus, even when skew occurs during the conveyance by the manual paper feed roller 13, the skew is corrected. afterwards,
After the motor is turned off for a predetermined time, the discharge motor 104 and the belt motor 102 are turned on (ment 7) to convey the document to the sheet paths (l) and (d), and the manual feed roller 13, the manual registration roller 11, and the wide The belt 7 is driven. At the same time, a size check counter for counting by a clock signal input from the belt clock is started (ment 8). Further, a belt registration counter counted by the belt excitation clock to stop at a predetermined position on the platen 3 is started (ment 9). When the manual feed registration sensor 34 is turned off and the rear end of the document is detected (ment 10), the size check counter is stopped, and the size check process (ment 11) shown in FIG. 43 is performed based on the data. At the same time, the paper discharge motor 104 is turned off because the rear end of the document has passed through the manual feed roller 13 (ment 12). Thereafter, when the started manual feed registration counter is completed (ment 13), the belt motor 102 is turned off (ment 14). Then, the discharge flapper solenoid 109 is turned off.

(Original document reading process) Next, the original document reading process will be described with reference to FIG.

The belt motor 102 is turned on (m
ove1), the wide belt 7 is driven. At the same time,
When the leading end of the document reaches a predetermined position, an image-on-counter, which is counted by the belt excitation clock, is started to turn on the image-point signal (move 2). At this time, the belt motor speed is controlled at a constant speed by outputting an excitation clock signal based on the reading speed data (V) received from the copying machine main body. Thereafter, when the started image on-counter ends (move 3), the image signal is turned on (transmitted to the copying machine body) (move 4).
After receiving the image point signal, the copier main body performs an actual image reading by arithmetically controlling the time until the leading edge of the document reaches the optical system fixed position during the flow reading. The image tip signal is turned off after a predetermined time has elapsed (mov
e5, 6, 7). Thereafter, when the rear end of the document has passed the reading position, the belt motor 102 is turned off (mo
ve8).

Also, the drift reading speed data (V) is
It may be equal to or different from the reading speed (V1) when the optical system moves. In particular, when V> V1, the document image is completely read in a shorter time than in the normal optical system moving reading, so that the use of the document transport device of the present invention improves the copying speed.

(Size Check Processing) Next, the size check processing will be described with reference to FIG.

In this size check process, the original document size is corrected by adding the distance from the nip position of the second feed roller 9 to the paper feed sensor 35 to the size check counter data as the document size determining means. (Length in the feed direction). At this time, the original is fed to the second feeding roller 35.
And the wide belt 7, and the feed amount and the count value by the belt excitation clock surely coincide with each other. Thereafter, A5 and B are used according to the corrected size data.
5, size determination of A4, B5R, A4R, B4, A3, etc. is performed.

Next, the printer section which is an image output section of 300 will be described with reference to FIG.

Reference numeral 100 denotes an upper cassette. Sheets in the cassette are separated and fed one by one by the action of a separation claw and a feeding roller 101, and are guided to a registration roller 106. 1
Reference numeral 02 denotes a lower cassette. Sheets in the cassette are separated and fed one by one by the action of a separation claw and a feeding roller 103, and are guided to a registration roller 106. A manual guide 104 guides sheet materials one by one to a registration roller 106 via a roller 105. Reference numeral 108 denotes a sheet stacking device (deck type), which is an intermediate plate 10 that is raised and lowered by a motor or the like.
8a, the sheets on the middle plate are separated and fed one by one by the action of
It is led to 0.

Reference numeral 112 denotes a sightseeing drum, 113 denotes a reading optical system, 114 denotes a developing unit, 115 denotes a transfer charger, and 116 denotes a separation charger, and constitutes an image forming unit.

Reference numeral 117 denotes a conveyance belt for conveying the sheet material on which an image has been formed, 118 denotes a fixing device, 119 denotes a conveyance roller, and 120 denotes a flapper. The sheet material on which the image is formed is guided to the discharge roller 121 by the flapper 120 and is conveyed into the sorter 122. The sorter 122 includes a non-sort tray 122a, a sort bin tray 122b,
It has a non-sort tray discharge roller 122c and a sort bin tray discharge roller 122d. The non-sort tray and the sort bin tray move up and down to sort sheets one by one.
Incidentally, a discharge tray may be mounted instead of the sorter.

An automatic document feeder 130 has a tray 130a, a separating means 130b, a return path 130c, and a discharge roller 130d. Documents are positioned one by one on the platen 131 by the apparatus 130 and read by the optical system. A transport belt 132 guides the document to the platen in a forward rotation (arrow A), and discharges the document from the platen in a reverse rotation.

For one document placed on the platen, an image is formed on the sightseeing drum according to the set number of copies, and the sheet material for the number of copies is stored in the cassette 10.
0, 102, or deck 108, the image is fed each time an image is formed on the photosensitive drum. The registration between the image on the photosensitive drum and the sheet material is performed by the registration roller 106.

When the required number of copies are formed, the original is discharged from the platen, and the next original is positioned on the platen. Hereinafter, the same applies.

Reference numeral 200 denotes an intermediate tray, which is used for forming an image on both sides of the sheet material or for forming an image on one side of the sheet material (multiple), once the sheet material on which the image is formed is used. Stock it. 201 is a conveying roller, 2
Numeral 02 is a transport belt, 203 is a flapper, 204 is a transport belt, and 205 is a transport roller. In the case of double-sided copying, the sheet is guided to the intermediate tray 200 through the path 206. The sheet has the image side facing up. In the case of multiple copying, the sheet material is guided to the intermediate tray 200 through the path 207. The sheet material has the image side facing down.

The sheet material stacked on the intermediate tray 200 is made up of auxiliary rollers 209 and 210, a forward / reverse separation roller pair 2
The sheets are separated one by one from below by the action of 11 and re-fed. The re-fed sheet materials are transport rollers 213, 2
14, 215, roller 110, registration roller 106
Through to the image forming unit. After image formation, the paper is discharged in the same manner as described above. One-sided copies are first made according to the number of copies set for one document placed on the platen, and they are stacked on the intermediate tray 200. After that, the original is reversed on the platen and guided again on the platen, and this image is read by the number of copies. The read image is formed on a sheet material re-fed from the intermediate tray 200 every time the image is read. They are sorted by the sorter 122 in page order.

On the other hand, when the original is
There is also a method of making only one copy for each circulation. According to this method, even when a plurality of copies are made, a copy group having the same page order can be obtained in order, so that a necessary number of copies can be obtained separately without a sorter.
When making a two-sided copy in this way, read both sides of one original sheet continuously, copy and eject both sides of the sheet material, and then eject the original sheet. By repeating the process many times, a divided double-sided copy group is obtained.

[0196]

As described above, according to the image forming apparatus of the first invention, the first and second document detecting means for detecting the document on the document tray, and the first and second document are provided. Determining means for determining whether or not there is a document having a different length on the document tray based on a result of the detecting means; and, if the determining means determines that there is no document having a different length, the selecting means determines whether or not there is a preceding document. Permission means for permitting advance paper feeding from the transfer paper feeding cassette selected for use, so that it is determined that there is no document with a different length, and the document reading position is changed one by one as in the conventional case. This eliminates the need to carry the sheet upward, check the document size, and select the transfer paper after the size is determined. As a result, the time for feeding the transfer paper is reduced, and the productivity of image formation can be increased.

According to the image forming apparatus of the second invention,
In the first aspect of the present invention, in the first sheet feeding mode, a transfer sheet feeding cassette selected for a preceding document in a mixed document loading mode in which documents having different sizes are simultaneously set on a document tray of an automatic document feeder to form an image. Since the paper is fed during the image formation from the printer, the feeding time of the transfer paper is shortened in the mixed document mode, and the productivity of image formation can be improved.

According to the image forming apparatus of the third invention,
In the first or second aspect of the present invention, there is provided a last document detecting means for detecting whether or not the document being conveyed is the last document, and prohibits preceding feeding when the last document detecting means detects the last document. So that the first
The same effect as that of the invention can be enjoyed.

According to the image forming apparatus of the fourth invention,
In the first to third aspects of the present invention, the second document detecting means is disposed at a distance from the first document detecting means at which a long document can be detected. When the determination is made, the pre-feed of the pre-transfer paper is performed, and the productivity of image formation can be increased.

According to the fifth aspect of the invention, there is provided an automatic document feeder for conveying a document placed on a document tray to an image reading position and discharging the document after image reading of the document is completed. A paper device, size detecting means for detecting the size of the document, and selecting means for selecting a transfer paper feed cassette for the document based on the result of the size detecting means; First and second document detecting means for detecting a document on a document tray are provided for an image forming apparatus which performs an image forming process of transferring to paper,
A determination process for determining whether or not there is a document having a different length on a document tray based on a result of the first and second document detection means;
When it is determined by the determination process that there is no original having a different length, a permission process of permitting the preceding paper from the transfer paper feed cassette selected for the preceding document by the selection means is executed. .

According to the control method of the image forming apparatus of the sixth invention, the first document detecting means for detecting the document on the document tray and the distance which can detect the long document from the first document detecting means. A second original detecting means is provided, and originals of different sizes are simultaneously set on an original tray of an automatic original feeder to form an image. A first step of checking the size of the document, a second step of selecting a transfer paper feed cassette according to the size of the document,
Performing a third step of determining whether the detection result of the second document detection means is in the first detection state or the second detection state after the step of Is in the first detection state, the first to third steps are repeatedly executed until the second detection state is reached. Further, under the second detection state, the size of the document is checked. After the transfer paper feed cassette is selected according to the above, the preceding paper feed from this cassette is permitted, so that the same effect as that of the first invention can be obtained simply and accurately.

According to the control method of the image forming apparatus of the seventh invention, in the above-mentioned sixth invention, in the preceding paper feeding, originals having different sizes are simultaneously set on the original tray of the automatic original feeding apparatus. In the mixed original mode in which the original is formed, the paper is fed during the image formation from the transfer paper feed cassette selected for the preceding original. Therefore, it is possible to obtain the same effect as the second invention.

According to the control method of the image forming apparatus of the eighth invention, in the sixth and seventh inventions, there is provided a final document detecting means for detecting whether or not the document being transported is the final document. Since the preceding document feeding is prohibited when the last document detecting means detects the last document, the same effect as that of the first invention can be enjoyed by a proper operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an image forming apparatus including an ADF according to an embodiment.

FIG. 2 is a detailed view of an image forming unit 300 of FIG.

FIG. 3 is an explanatory diagram of an ADF path according to the embodiment.

FIG. 4 is a drive system diagram of the ADF of the embodiment.

FIG. 5 is an explanatory diagram illustrating an operation of a separation unit of the ADF according to the embodiment.

FIG. 6 is an explanatory diagram illustrating an operation of a separation unit of the ADF according to the embodiment.

FIG. 7 is a diagram illustrating the operation of the separation unit of the ADF according to the embodiment.

FIG. 8 is a diagram illustrating the operation of the separation unit of the ADF according to the embodiment.

FIG. 9 is a plan view of the ADF.

FIG. 10 is a configuration explanatory view of main members of the ADF.

FIG. 11 is a diagram illustrating a document reading position.

FIG. 12 is a diagram illustrating a document reading position.

FIG. 13 is a diagram illustrating a flow of a half-size document in the single-sided document transport mode.

FIG. 14 is a diagram illustrating the flow of a half-size document in the single-sided document transport mode.

FIG. 15 is a diagram illustrating a flow of a large-size document in a single-sided document transport mode.

FIG. 16 is a diagram illustrating a flow of a large-size document in a single-sided document transport mode.

FIG. 17 is a diagram illustrating a flow of a half-size document in a double-sided document conveyance mode.

FIG. 18 is a diagram illustrating a flow of a half-size document in a duplex document transport mode.

FIG. 19 is a diagram illustrating the flow of a half-size original in the duplex original transport mode.

FIG. 20 is a diagram illustrating a flow of a half-size document in a double-sided document conveyance mode.

FIG. 21 is a diagram illustrating a flow of a large-size document in a double-sided document conveyance mode.

FIG. 22 is a diagram illustrating a flow of a large-size document in a double-sided document conveyance mode.

FIG. 23 is a diagram illustrating a flow of a large-size document in a double-sided document transport mode.

FIG. 24 is a diagram illustrating a flow of a large-size document in a double-sided document conveyance mode.

FIG. 25 is a diagram illustrating a flow of a document when a manual document is conveyed.

FIG. 26 is a diagram illustrating a flow of a document when a manual document is conveyed.

FIG. 27 is a block diagram illustrating a circuit configuration of a control device according to an embodiment.

FIG. 28 is a flowchart illustrating an example of a copy machine main body feed control of the present invention.

FIG. 29 shows the ADF indicating an arrangement position of a document detection sensor;
FIG.

FIG. 30 is a main flowchart of the embodiment.

FIG. 31 is a flowchart of a first moving reading mode.

FIG. 32 is a flowchart of a second drift reading mode.

FIG. 33 is a flowchart of a duplex document mode.

FIG. 34 is a flowchart of paper feed roller lowering control.

FIG. 35 is a flowchart of paper feed roller raising control.

FIG. 36 is a flowchart of separation control.

FIG. 37 is a flowchart of paper feed control.

FIG. 38 is a flowchart of a document pre-reversal process.

FIG. 39 is a flowchart of a reversing process.

FIG. 40 is a flowchart of a sheet discharging process.

FIG. 41 is a flowchart of a process of reading a document in a stream.

FIG. 42 is a flowchart of a size check process.

FIG. 43 is a flowchart of a manual sheet feeding process.

FIG. 44 is a flowchart of a manual document mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 2 ADF 3 Platen 4 Document tray 10 Paper discharge tray 30 Separation sensor 32 Mixed detection sensor 33 Reverse detection sensor 35 Feed sensor 40 Document set sensor 41 Document rear end detection sensor 43 Final document detection sensor 44 Paper width detection sensor 200 Reader Unit 208 Image sensor 300 Printer unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayuki Fujii 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuzo Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the corporation

Claims (8)

[Claims] An automatic document feeder for transporting a document placed on a document tray to an image reading position and discharging the document after the image reading of the document is completed; and a size detecting means for detecting the size of the document. An image forming apparatus for performing an image forming process of transferring a result of the image reading to a selected transfer sheet, the selecting means for selecting a transfer sheet feeding cassette for the document based on the result of the size detecting means Wherein first and second document detecting means for detecting a document on the document tray, and a document having a different length on the document tray based on a result of the first and second document detecting means. Determination means for determining whether or not there is no original having a different length; and when the determination means determines that there is no original having a different length, the preliminary feeding from the transfer paper feeding cassette selected for the preceding original by the selecting means is permitted. Permission means An image forming apparatus comprising: 2. The method according to claim 1, wherein the first sheet feeder is a sheet feeder selected for the preceding document in a mixed document mode in which documents having different sizes are simultaneously set on a document tray of the automatic document feeder to form an image. 2. The image forming apparatus according to claim 1, wherein the sheet is fed during image formation from a cassette. 3. A method according to claim 1, further comprising: a last document detecting means for detecting whether or not the document being conveyed is the last document, wherein the preceding sheet feeding is inhibited when the last document detecting means detects the last document. The image forming apparatus according to claim 1 or 2, wherein 4. An image forming apparatus according to claim 1, wherein said second document detecting means is arranged at a distance from said first document detecting means at which a long document can be detected. . 5. An automatic document feeder for transporting a document placed on a document tray to an image reading position and discharging the document after reading the image of the document, and a size detecting means for detecting the size of the document. An image forming apparatus for performing an image forming process of transferring a result of the image reading to a selected transfer paper, the selecting means for selecting a transfer paper feed cassette for a document based on a result of the size detection means And first and second document detecting means for detecting a document on the document tray are provided. Based on the results of the first and second document detecting means, a length of A determination process for determining whether or not there is a different document; and, if the determination process determines that there is no document having a different length, the advance feeding from the transfer paper feed cassette selected for the preceding document by the selection means. Allow paper A control method for an image forming apparatus, comprising: executing a permission process. 6. An automatic document feeder for conveying a document placed on a document tray to an image reading position and discharging the document after the image reading of the document is completed, and a size detecting means for detecting the size of the document. An image forming apparatus for performing an image forming process of transferring a result of the image reading to a selected transfer paper, the selecting means for selecting a transfer paper feed cassette for a document based on a result of the size detection means In contrast, a first document detecting means for detecting a document on the document tray and a second document detecting means arranged at a distance from the first document detecting means capable of detecting a long document are provided. When a mixed document mode is set in which documents of different sizes are simultaneously set on the document tray of the automatic document feeder to form an image, a size check of the document conveyed to the image reading position is performed. A second step of selecting a transfer paper feed cassette according to the size of the original, and after the second step, a detection result of the second original detecting means is set to a first detection state or a second detection state. Performing a third step of determining whether the document is in one of the detection states. If the detection result of the second document detection means is the first detection state, the second document detection means is switched to the second detection state. Steps 1 to 3 are repeatedly executed. Further, under the second detection state, the size of the original is checked, and a transfer paper feed cassette according to the original size is selected. A control method of the image forming apparatus, wherein the preceding sheet feeding is permitted. 7. The pre-feeding operation includes feeding a transfer sheet selected for the preceding document in a document mixing mode in which documents of different sizes are simultaneously set on a document tray of the automatic document feeder to form an image. 7. The method according to claim 6, wherein the sheet is fed during image formation from a cassette. 8. A system according to claim 1, further comprising a final document detecting means for detecting whether the document being transported is the last document, and prohibiting the preceding feeding when the last document detecting means detects the final document. 8. The control method for an image forming apparatus according to claim 6, wherein: