JPH1172976A - Image forming device and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time required for reading both sides of a document, to reduce damage to the document and soil on a document reading part, to facilitate handling, and to start image formation in a short time. SOLUTION: The image forming device consists of an automatic document feeder and a device main body 100. The automatic document feeder is equipped with a first carrying-direction-switching means 55 for switching to a circulation path PS 1 or a switch-back carrying-in path PS 4, and a second carrying-direction-switching means 56 for switching to the circulation path PS 1 or an ejection path PS 3. The device main body 100 is equipped with a means 61 for reading document-image information in the document reading position P1 of the circulation path, a document-reading-mode selection means for selecting a one-side-reading mode by which the first side of the document is read or a mode by which the document is circulated by a document inverting part 8 and both its sides are read, and a means for controlling image formation. On receiving an image formation start signal, the device controls the setting of a memory area for storing the document-image information in, the selection of transfer paper, and document feed for reading the document image based on document- size information from a size detection means S provided on a paper feed table 10.

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 capable of automatically feeding documents sequentially and reading both surfaces of a first surface and a second surface, and a control method therefor.

[0002]

2. Description of the Related Art Some image forming apparatuses include an automatic document feeder capable of automatically feeding documents sequentially and reading both sides thereof. There is a document processing machine disclosed in Japanese Unexamined Patent Publication No. Hei 7-175279. In this document processing machine, when reading both sides of a document, the document is first fed, the first side is read, and the document is conveyed to a paper discharge tray. The sheet is fed, the second side is read, and the sheet is conveyed to a sheet discharge tray. Further, even if the originals are sequentially stacked, the originals are switched back again on the output tray so that the pages are stacked with the first side down so that the page order is aligned, and the originals are discharged to the output tray via the original conveyance path. And loaded.

[0003]

As described above, when reading both sides of an original, the originals are stacked with the first side down so that the page order becomes the same even when the originals are sequentially stacked. The switchback is reversed on the paper discharge tray, discharged to the paper discharge tray via the document conveyance path, stacked, and the document passes through the document reading unit three times. In the third pass, the document is not read. Regardless, since the document is passed through the document reading unit, the next document cannot be fed, which is an adverse effect on the improvement of the document reading speed. In addition, the length of the document conveyance path becomes longer, and the damage to the document due to the pressure and friction applied when the document is conveyed increases. Furthermore, even though the document is not read, the document is passed through the document reading unit and the number of times of passing through the document reading unit is increased.
It is necessary to frequently clean the document reading unit.

In an automatic document feeder, documents of various sizes can be placed on a paper feed table, and the width of the document and the time required to pass through the sensor are determined by sensors provided on the document transport path. To determine the size of the original and to control the selection of the transfer paper and the reading of the original image according to the original size. Size cannot be determined.

Therefore, the setting of the memory area for storing the original image information, the selection of the transfer paper, and the control of the feeding of the original for reading the original image can only be performed after the original size is determined. It took time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and shortens the time required to read both sides of a document, reduces the damage to the document, and reduces the dirt on the document reading section to facilitate handling. In addition, an object of the present invention is to provide an image forming apparatus capable of starting image formation in a short time by detecting the size of a document while being placed, and a control method thereof.

[0007]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to a first aspect of the present invention, there is provided a paper feed tray on which an original is placed, a discharge tray on which the original after reading is loaded,
A circulation path having a document reading position, a supply path for supplying a document from the paper feed table to the circulation path, and a discharge path for discharging the read document from the circulation path to the paper output tray; A switchback carry-in path for carrying in the document from the circulation path, a front / back inversion means for switching back the carried-in document and reversing the front and back, and a switchback carry-out path for carrying out the front / back reversed document to the circulation path. A first reversing portion provided at a connection portion between the circulation path and the switchback carry-in path, for switching a document conveyance direction to the circulation path or the switchback carry-in path; Switching means, provided at a connection portion between the circulation path and the discharge path, for switching a document conveying direction to the circulation path or the discharge path; A second conveying direction switching means to obtain,
Automatic document feeder, a document reading means for reading document image information at a document reading position in the circulation path, a one-sided reading mode for reading the first side of the document, An image forming apparatus comprising: a document reading mode selecting unit for selecting a double-side reading mode for circulating and reading a first surface and a second surface; and an image forming apparatus main body including a control unit for controlling image forming. In the apparatus, the paper feed tray is provided with size detection means for detecting the size of the document while the document is placed, and the control means receives an image formation start signal and detects the size of the document by the size detection means. Setting of a memory area for storing document image information based on the document size information, selection of a transfer sheet, and control of document feeding for reading a document image An image forming apparatus comprising and. 』
It is.

According to the first aspect of the present invention, the original, which has been read on both sides of the first and second surfaces, is inverted by the original front / back reversing portion downstream of the original reading position on the circulation path, and the paper discharge tray After the sheet is discharged, the next original is immediately sent to the original reading position, and the first side can be read, and the reading time of both sides of the original can be reduced. In addition, the original that has been read on both sides is inverted by the original upside down unit downstream of the original reading position, so that the original does not pass through the original reading position despite the fact that the original is not read as in the related art. In addition to reducing the damage to the original, the dirt at the original reading position can be reduced and the handling is easy.

In addition, instead of detecting the width of the original and the time it takes to pass through the sensor as in the prior art, the original size is not determined, but the size of the original is detected and the image formation start signal is received. Since the setting of the memory area for storing the original image information, the selection of the transfer paper, and the feeding of the original for reading the original image are controlled based on the obtained original size information, the image formation can be started in a short time.

According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein the size detecting means comprises a document width detecting means and a length detecting means. ].

According to the second aspect of the present invention, it is possible to easily and reliably detect the size of the original placed on the paper feed tray in a state where the original is placed.

According to a third aspect of the present invention, there is provided an image forming apparatus, comprising: a sheet discharging tray provided below the sheet feeding tray; and the document reversing section provided below the sheet discharging tray. 3. The image forming apparatus according to claim 1, wherein the document reversing section is positioned on the same side of the circulation path as the document reading position. ].

According to the third aspect of the present invention, by arranging the paper feed tray, the paper discharge tray, and the document reversing section, the document can be provided without increasing the size of the apparatus even if the document reversing section is provided. The reading time of both sides can be reduced.

According to a fourth aspect of the present invention, there is provided a sheet feeding table on which an original is placed, a discharge tray on which the original after reading is loaded,
A circulation path having a document reading position, a supply path for supplying a document from the paper feed table to the circulation path, and a discharge path for discharging the read document from the circulation path to the paper output tray; A switchback carry-in path for carrying in the document from the circulation path, a front / back inversion means for switching back the carried-in document and reversing the front and back, and a switchback carry-out path for carrying out the front / back reversed document to the circulation path. A document reversing unit for reversing the front and back of a document, and a first transport direction provided at a connection between the circulation path and the switchback carry-in path, for switching a document transport direction to the circulation path or the switchback carry-in path. Switching means, provided at a connection portion between the circulation path and the discharge path, for switching a document conveying direction to the circulation path or the discharge path; A second conveying direction switching means to obtain,
Automatic document feeder, a document reading means for reading document image information at a document reading position in the circulation path, a one-sided reading mode for reading the first side of the document, An image forming apparatus comprising: a document reading mode selecting unit for selecting a double-side reading mode for circulating and reading a first surface and a second surface; and an image forming apparatus main body including a control unit for controlling image forming. In the control method of the apparatus, the paper feed tray is provided with size detecting means for detecting the size of the document while the document is placed, and the image forming start signal is received by the control means and the size is detected by the size detecting means. Setting of a memory area for storing original image information based on the obtained original size information, selection of a transfer sheet, and feeding of the original for reading the original image Method of controlling an image forming apparatus and controls. ].

According to the fourth aspect of the present invention, the original which has been read on both sides of the first and second surfaces is inverted by the original front / back inverting portion downstream of the original reading position of the circulation path, and the paper output tray After the sheet is discharged, the next original is immediately sent to the original reading position, and the first side can be read, and the reading time of both sides of the original can be reduced. In addition, the original that has been read on both sides is inverted by the original upside down unit downstream of the original reading position, so that the original does not pass through the original reading position despite the fact that the original is not read as in the related art. In addition to reducing the damage to the original, the dirt at the original reading position can be reduced and the handling is easy.

In addition, instead of detecting the width of the original and the time it takes to pass through the sensor as in the prior art, the size of the original is not determined, but the size of the original is detected. Since the setting of the memory area for storing the original image information, the selection of the transfer paper, and the feeding of the original for reading the original image are controlled based on the obtained original size information, the image formation can be started in a short time.

According to a fifth aspect of the present invention, there is provided a method for controlling an image forming apparatus according to the fourth aspect, wherein the size detecting means comprises a document width detecting means and a length detecting means. . ].

According to the fifth aspect of the present invention, it is possible to easily and reliably detect the size of the original placed on the paper feed tray in a state where it is placed.

According to a sixth aspect of the present invention, there is provided the image forming apparatus, wherein, when the two-sided reading mode is selected by the document reading mode selecting means, the control means reads the image on the first surface at the document reading position on the circulation path. The first transport direction switching means is controlled so that the fed original is carried into the original front / back reversing unit, and the original carried into the original front / back reversing unit is carried out to the circulation path and turned upside down to the original reading position. The second transport direction switching means is controlled to transport the original document, and the first transport direction switching means is transported again to transport the original having the image read on the second surface at the original reading position to the original reverse side. And controlling the second transport direction switching means so that the document re-conveyed to the document reversing section is carried out to the circulation path and then discharged to the paper discharge tray. Method of controlling an image forming apparatus according to claim 4 or claim 5, wherein. ].

According to the sixth aspect of the invention, when the double-sided reading mode is selected, the next original is immediately controlled by simple control by switching the first transport direction switching means and the second transport direction switching means. Can be sent to the document reading position in the circulation path to read the first side, and the reading time of both sides of the first and second sides of the document can be reduced. In addition, since the original that has been read on both sides is inverted by the original upside down unit and discharged to the output tray, the original reading position is set to be inverted even though the original is not read as in the related art. , The damage to the document can be reduced, and the dirt attached to the glass of the document reading section can be reduced, so that the handling is easy.

According to a seventh aspect of the present invention, a document is placed on the sheet feeder such that the surface of the first page is the uppermost surface, and one page of the document placed on the sheet feeder. The original is conveyed so as to be sequentially read from the image on the front surface of the eye, and the original after reading the image on both sides is discharged so as to be sequentially stacked with the front surface down on the discharge tray. A method for controlling an image forming apparatus according to claim 6. ].

According to the seventh aspect of the present invention, since the original can be placed on the paper feed tray so that the front side of the original is on the top, the user can form an image while checking the image on the front side of the original. This makes it possible to discharge the original on which the reading of the double-sided image has been completed onto the discharge tray in a state where the pages are arranged in order, thereby greatly improving the operability.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus and a control method thereof according to the present invention will be described in detail with reference to the drawings. FIG.
FIG. 2 is a sectional view of an automatic document feeder provided in the image forming apparatus, and FIG. 2 is a plan view of a document feeder.

The automatic document feeder 1 provided in the image forming apparatus is a compact device for electronically inputting not only one side but also both sides of the document 2 in the order of 1 to N, and includes an electronic copier, a facsimile, and the like. Alternatively, it is applied to a scanner or the like. The automatic document feeder 1 includes a document feeding unit 3, a registration unit 4, a conveyance unit 5, a document reading unit 6, and a discharge tray 7
The document 2 stacked on the paper feed table 10 of the document feed unit 3 is sequentially fed to the document reading unit 6 to read the first side and to the output tray 7. The original 2 on which the first side has been read or which has been read is inverted by the original front / reverse inverting unit 8 and is sequentially fed to the original reading unit 6 to read the second side and is discharged onto the paper output tray 7. Paper is available.

The originals 2 can be stacked and set on the paper supply table 10 of the original paper supply section 3, and an empty sensor S 1 is arranged upstream of the paper supply table 10 to detect the presence or absence of the original 2. . Guide plates 11 are provided on both sides of the paper feed table 10 so as to be movable in the document width direction, and the guide plates 11 are provided with plates 12 extending inward in the document width direction.

A rack 13 is provided on the opposite side of the plate 12.
The rack 13 is provided with a pinion 1 of a rotating shaft 14.
5 is engaged. By moving the guide plate 11 in the document width direction according to the width of the document 2, the rotation shaft 14 rotates via the plate 12, and the amount of rotation is detected by the document width detection sensor S2. The document width detection sensor S2 is composed of, for example, a rotary volume.

Further, a plurality of document length detecting sensors S3a to S3c are arranged at predetermined positions in the feeding direction on the sheet feeding table 10. In this embodiment, the document length detection sensor S3
a to S3c are arranged three times. Each of the document length detection sensors S3a to S3c includes, for example, a limit switch and an optical sensor. In this embodiment, the size detecting means S is constituted by the document width detection sensor S2 and the document length detection sensors S3a to S3c, and detects the size of the set document from the document width information and the document length information. And control information of the device.

In this embodiment, as shown in FIG. 2A, if only the document length detection sensor S3a is ON, the document size is set to B5R or A4 based on the width information of the document width detection sensor S2. to decide. When the document length detection sensors S3a and S3b are turned on, the document width detection sensor S2
It is determined whether the document size is A4R or B5R based on the width information. Further, when the document length detecting sensors S3a, 3b, 3c are on, it is determined whether the document size is B4 or A3 based on the width information of the document width detecting sensor S2.

As described above, the size detecting means S comprises the document width detecting sensor S2 as the document width detecting means and the document length detecting sensors S3a to S3c as the length detecting means. In a state where the size of the placed document is placed, it can be detected simply and reliably.

On the downstream side of the paper feed table 10, a paper feed roller 30 is provided.
And the separation roller 31 are arranged in order. The paper feed roller 30 is normally at the standby position, moves from the standby position to the paper feed position by the operation of the paper feed clutch 32, rotates at a predetermined timing, and sends out the document 2. The separation roller 31 is arranged to face the separation pad 33 and separates the document 2 so that a plurality of documents 2 are not sent out. Detection of the separated document 2 is performed by the separation sensor S4.

The registration section 4 is arranged downstream of the document feeding section 3 and the separated document 2 is fed. Resist part 4
, A registration clutch 40 and a registration roller 41 are arranged. The registration clutch 40 rotates the normally stopped registration roller 41 at a predetermined timing. When the leading end of the document 2 comes into contact with the registration roller 41, the registration lever 42 is operated by the document 2 and the registration sensor S5 detects the registration state. After a certain period of time, the registration roller 41 is rotated by the registration clutch 40, and the document 2 is transported from the registration unit 4 to the transport unit 5.

The transport section 5 has a transport roller 50 and platen rollers 51 and 52. The platen rollers 51 and 52 are arranged around the transport roller 50, and the original 2 is transported to the original reading section 6 by driving them. You.

An original reading sensor S6 is arranged upstream of the original reading section 6, and outputs an original reading trigger signal when the original 2 is detected. When the leading end of the document 2 reaches the document reading sensor S6, the document 2 temporarily stops and enters a standby state. When a reading start signal is received from the document reading control unit 20, the conveyance of the document 2 is restarted. When the document 2 passes over the surface of the glass 60, the document reading unit 61 reads the document 2.

The document front / back reversing unit 8 is provided downstream of the document reading unit 6 and upstream of the sheet discharge tray 7. A reversing roller 80 is disposed in the document reversing section 8, and is switched back and reversed on a reversing tray 81 by the forward and reverse rotation of the reversing roller 80 and sent out. An inversion detection sensor S7 is arranged near the inversion roller 80.

A discharge roller 70 is disposed upstream of the discharge tray 7, and a discharge sensor S 8 is disposed near the discharge roller 70 to detect the discharge of the document 2. Inversion detection sensor S7
The paper ejection sensor S8 is constituted by, for example, a reflection sensor.

Around the transport roller 50, the first
A first transport direction switching unit 55 for switching the reading between the surface and the second surface, and a second transport direction switching unit 56 for switching between the reading of the second surface and the paper discharge are arranged.

The original 2 is sent from the original feeding section 3 to the registration section 4, and is switched from the registration section 4 through the original reading section 6 to the first discharge direction 7 by switching of the first transport direction switching means 55. The conveyance path A and the original 2
To the registration unit 4, and from the registration unit 4 via the document reading unit, the document 2 whose first surface has been read by switching of the first conveyance direction switching unit 55 is transported to the document front / back reversing unit 8. The conveyance path B and the original 2 reversed by the original front / back reversing unit 8 are sent to the registration unit 4 by switching of the second conveyance direction switching unit 56 and circulated to the original reading unit 6 to read the second side and read the front / back of the original. A third transport path C that is reversed by the reversing unit 8 and reaches the sheet discharge tray 7 by switching between the first transport direction switching unit 55 and the second transport direction switching unit 56 is provided.

As described above, according to the image forming apparatus of the present invention, the circulation path PS1 having the document reading position P1 and the sheet feeding table 1
0, a supply path PS2 for supplying the document to the circulation path PS1, a discharge path PS3 for discharging the read document from the circulation path PS1 to the sheet discharge tray 7, and a circulation path PS.
A switchback carry-in path PS4 for carrying the original from 1;
The reversing roller 80 constituting a front / back reversing means for switching back the fed document and reversing the front / back, and a switchback carrying-out path PS5 for carrying the reversed document to the circulation path PS1. A first transport direction switching unit 55 that is provided at a connection between the circulation path PS1 and the switchback carry-in path PS4 and that switches the document transport direction to the circulation path PS1 or the switchback carry-in path PS4; An automatic document feeder 1 provided at a connection portion between the circulation path PS1 and the discharge path PS3 and provided with second conveyance direction switching means 56 for switching the conveyance direction of the document to the circulation path PS1 or the discharge path PS3; Document reading means 61 for reading document image information at a document reading position P1 of the circulation path PS1; There.

A paper discharge tray 7 is provided below the document feeder 3.
Further, a document reversing section 8 is provided below the sheet discharge tray 7, and the document feeding section 3, the sheet discharge tray 7 and the document reversing section 8 are placed on the same side of the document reading position P1 of the circulation path PS1. Have been placed. In this way, by arranging the document feeder 3, the paper discharge tray 7, and the document reversing unit 8, even if the document reversing unit 8 is provided, both sides of the document 2 can be read without increasing the size of the apparatus. Time can be reduced.

FIG. 3 is a schematic diagram showing the driving of the automatic document feeder and the arrangement of sensors, and FIG. 4 is a control block diagram of the image forming apparatus.

The image forming apparatus includes an automatic document feeder 1 and a main body 100 of the image forming apparatus. The document reading control unit 20 of the automatic document feeder 1 includes an empty sensor S1, a document width detection sensor S2, three document length detection sensors S3a to S3c, a separation sensor S4, a registration sensor S
5, detection information from the original reading sensor S6, the reversal detection sensor S7, and the paper ejection sensor S8 are input. The document reading control unit 20 includes a reading start switch SW
1. Signals from the single-sided reading mode switch SW2 and the double-sided reading mode switch SW3 are input.

Based on the sensor information and the switch information, the original reading control unit 20 controls the sheet feeding clutch 32, the registration clutch 40, the DC motor M1, and the pulse motor M.
2. Control the DC solenoids SOL1 and SOL2. D
The C motor M1 drives the sheet feeding roller 30 and the separation roller 31, and also drives the reversing roller 80. The pulse motor M2 drives the registration roller 41, the transport roller 50, and the paper discharge roller 70. DC solenoid SOL1
Operates the first transport direction switching means 55 and the second transport direction switching means 56. Further, the DC solenoid SOL2 turns off the reversing roller 80 for a predetermined time.

The original reading control unit 20 operates in a one-side reading mode for reading the first side of the original and a two-side reading mode for operating the original turning unit 8 to circulate the original and read the first and second sides. A document reading mode selecting means for selecting the document is provided, and the document reading mode is selected by inputting a signal from the single-side reading mode switch SW2 or the double-side reading mode switch SW3.

The main body 100 of the image forming apparatus is provided with a main body control section 101 constituting control means for controlling image formation. The main body driving unit 102, the document reading unit 61, the image processing unit 103, and the writing unit 104 are controlled. The document image information read by the document reading unit 61 is image-processed by the image processing unit 103, temporarily stored in the image memory 105, and recorded on the recording paper by the writing unit 104.

The main body control unit 101 receives the image formation start signal from the operation unit 110 and sets a memory area of the image memory 105 for storing the document image information based on the document size information detected by the size detecting means S. In addition, the image forming apparatus main body driving unit 102 is driven to control selection of a transfer sheet and feeding of a document for reading a document image.

As described above, instead of detecting the width of the document and the time required to pass through the sensor as in the prior art, the size of the document is detected without detecting the size of the document, and the image formation start signal is received. Memory area for storing document image information based on document size information detected by
In addition, since the feeding of the document for reading the document image is controlled, the image formation can be started in a short time.

FIG. 5 is an operation timing chart for reading both sides of a document by the automatic document feeder. The document 2 is placed on the sheet supply table 10 such that the surface of the first page is the top surface. When the document 2 is set, the empty sensor S1 is turned on and the document 2 is detected. Then, when the reading start switch SW1 is turned on, the document 2 is conveyed so as to be sequentially read from the image on the front surface of the first page of the document 2 placed on the paper feed table 10. That is, the paper feed clutch 32
Operates, and after a predetermined time t1, the DC motor M1
Rotates forward for a predetermined time t2, rotates the paper feed roller 30 and the separation roller 31, and sends out the original 2 of the first page, and the separation sensor S4 and the registration sensor S5 detect the original 2. D
The C motor M1 stops rotating, and after a predetermined time t3, the paper feed clutch 32 is turned off and the registration clutch 4
After 0 is turned on and the document 2 is positioned by the registration roller 41, the document 2 is transported at a predetermined transport timing.

The pulse motor M2 is driven a predetermined time t4 after the registration clutch 40 is turned on,
Is rotated to transport the original 2, the original reading sensor S6 detects the original 2, and the driving of the pulse motor M2 is stopped.
At a predetermined time t5, the DC solenoid SOL1 is driven and the first
The transport direction switching means 55 and the second transport direction switching means 56 are switched to the first surface reading side. The pulse motor M2 is driven to rotate the transport roller 50 to read the first side, and the inversion detection sensor S7 detects the original 2
Is detected, the DC motor M1 is driven for a predetermined period of time t6, the reversing roller 80 is rotated forward, and the document 2 is sent to the document reversing unit 8.

At this time, when the document reading sensor S6 does not detect the document 2, the DC solenoid SOL2 is operated after a predetermined time t7, and the reversing roller 80 is driven for a predetermined time t8.
The original 2 is sent to the registration unit 4 by pressing the reversing roller 80 reversely after a predetermined time t9 from the stop of the DC motor M1. With the reversal of the document 2, the reversal detection sensor S7 and the registration sensor S5 detect the document 2, the registration clutch 40 operates again, the registration roller 41 positions the document 2, and the document 2 is transferred at a predetermined transport timing. Transport.

After a predetermined time t10 after the registration clutch 40 is turned off, the pulse motor M2 is driven to rotate the conveying roller 50 to convey the original 2, and the DC solenoid SOL
1 to switch the first transport direction switching means 55 and the second transport direction switching means 56 to the second surface reading side. When the pulse motor M2 is driven to rotate the transport roller 50 to read the second surface and the reversal detection sensor S7 detects the document 2, the DC motor M1 drives the reversing roller 80 for a predetermined time t20 to correct the reversal roller 80. Then, the original 2 is sent to the original upside down section 8.

At this time, when the document reading sensor S6 does not detect the document 2, the DC solenoid SOL2 is operated after a predetermined time t7 to turn the reversing roller 80 for the predetermined time t2.
1 pressure contact, and a predetermined time t22 from the stop of the DC motor M1.
Thereafter, the reversing roller 80 is rotated in the reverse direction and is sent to the sheet discharging roller 70 via the second conveying direction switching means 56, and the DC motor M1 is driven for a predetermined time t11 to rotate the sheet discharging roller 70 in the reverse direction to discharge the document 2. The paper is discharged to the plate 7. Similarly, reading of the first side of the next original 2 is performed.

As described above, the original 2 is placed on the paper feed tray 10 such that the surface of the first page is the topmost surface, and the first page of the original placed on the paper feed tray 10 is placed. The document 2 that has been conveyed so that reading is performed sequentially from the front side image and the reading of both sides of the image is completed is discharged onto the discharge tray 7 so that the front side is sequentially stacked. Since the document 2 can be placed on the paper feed table 10 so that the front surface of the document 2 is on the top side, the user can perform image formation while checking the image on the front surface of the document 2, and the reading of the double-sided image is completed. It is possible to discharge the original 2 onto the paper discharge tray 7 in a state where the page order is aligned, so that the operability is remarkably improved.

Next, an automatic document reading method will be described with reference to FIG. FIG. 6 is a flowchart of document reading. The automatic document feeder has a single-sided reading mode for reading the first side of the document 2 and a double-sided reading mode for circulating the document 2 to read both the first and second sides.

In the automatic document feeder, a document size detection sensor S is provided on a sheet supply table 10 of the document supply section 3.
As soon as the original 2 is placed, the original size is detected, and the original size is set in the original reading control unit 20. Manuscript 2
When the first side is set upward as shown in FIG. 1 and the copy button on the operation panel is pressed, the reading start switch SW1 is operated, and upon receiving the signal, the flowchart of FIG. 6 is started. The upper document 2 of the documents set in the document feeder 3 is separated and fed to the registration unit 4 (step a).

Next, when it is detected that the document 2 has been registered on the registration rollers 41, it is determined whether or not the mode is the double-sided reading mode (step b). . In the single-sided reading mode, the original 2 is sent from the supply path PS2 to the original reading section 6 provided at the original reading position P1 on the circulation path PS1 (step c), and the presence or absence of the original 2 stacked on the original feeding section 3 is determined. Detection is performed based on the information of the sensor S1 (step d), and if there is the next original 2 stacked on the original feeding unit 3, the process proceeds to step a and the original 2 is sequentially sent to the original reading unit 6 and the first original 2 is sent to the first original reading unit 6. The surface is read, and the sheet is discharged to a sheet discharge tray 7 downstream of the document reading unit 6.

In step b, in the case of the double-side reading mode, the original 2 is moved from the supply path PS2 to the circulation path PS.
The document is sent to the document reading unit 6 provided at the first document reading position P1 to read the first surface (step e), and is conveyed downstream of the document reading unit 6 to the document front / back reversing unit 8 (step f). The original 2 whose surface has been read is inverted by the original front / reverse inverting unit 8 to form a circulation path PS1.
The document 2 having been read on both sides is inverted by the original front / back reversing unit 8 and discharged from the discharge path PS3 to the discharge tray 7 (step h). Then, the process proceeds to step d, and if there is the next original 2 stacked on the original feeding unit 3, the process proceeds to step a.
Then, both sides of the original are read in the same manner.

In this double-sided reading mode, the first transport direction switching means 55 and the second transport direction switching means 56 are controlled to switch to a desired transport path based on information on the first and second surfaces of the document 2. .

That is, the original 2 sent from the registration unit 4
Is transported by the first transport path A, and the leading edge of the document is detected by a document reading sensor S6 provided upstream of the document reading unit 6, and is transported to the document reading unit 6. When the leading edge of the document is detected, a timer for determining the timing of reading and starting by the document reading unit 6 is operated, and the timing of starting reading is determined. At this timing, the reading of the document 2 is started by the document reading unit 6 and the reading is completed according to the document size.

The original 2 that has passed through the original reading unit 6 is controlled by the original reading control unit 20 based on the setting information of the one-sided reading mode or the two-sided reading mode. 56
Switches the transfer path, and determines the transfer direction.
In the case of the single-sided reading mode, the first transport direction switching means 55 and the second transport direction switching means 56 are switched to the paper discharge tray 7 side, and the original 2 is placed on the paper discharge tray 7 via the first transport path A. The paper is discharged with the surface facing down.

In the case of the double-side reading mode, the first transport direction switching means 55 is switched to the original reverse side 8 on the second transport path B side, and the original 2 is switched to the original reverse side 8.
Transported to The original 2 conveyed to the original front / reverse inversion unit 8 is detected by an inversion detection sensor S7 provided in the original front / reverse inversion unit 8 to detect the leading edge of the original. It is conveyed to the reversal space on the reversing tray 81 provided. When the document 2 having a predetermined length is conveyed to the reversing space, the reversing roller 80 is switched to reverse rotation, and the reversing roller 80 rotates so as to convey the document 2 to the conveying path side, thereby reversing the document 2. .

The manuscript 2 sent from the manuscript front / back reversing unit 8 is controlled by the control unit 20 according to the information of the manuscript 2 after reading the first side or the manuscript 2 after reading the second side. The transport path is switched by the transport direction switching means 56, and the transport direction of the document is determined. In the case of the original 2 whose first surface has been read, the second transport direction switching means 56 has been switched to the circulation path side of the third transport path C, and the original 2 passes through the circulation path of the third transport path C. It is conveyed to the registration unit 4 for reading two surfaces. In the case of the original 2 whose second surface has been read, the second transport direction switching means 56 has been switched to the discharge tray 7 side, and the original 2 is transported and discharged to the discharge tray 7. At this time, since the document 2 is inverted again, the document 2 is discharged to the sheet discharge tray 7 with the first surface facing downward. As a result, the original 2 to be discharged is stacked on the output tray 7 with the first side facing down, both the one-sided original and the double-sided original, so that the order of the original 2 is not changed.
Loaded on top. When the last side is one side, immediately after reading the first side original, and when the last side is both sides, after detecting the original 2 in the second side original reverse side, the presence or absence of the next original 2 is determined. In some cases, feeding of the next original 2 is started,
The document is conveyed in the same manner as the first document. If the next original 2 does not exist, the operation is stopped when the discharge of the original is completed.

As described above, the original 2 which has been read on both sides is inverted by the original front / reverse inverting unit 8 downstream of the original reading unit 6 and is discharged to the paper output tray 7, and immediately the next original 2 is read by the original reading unit. 6, the first side can be read, and the reading time of both sides of the document 2 can be reduced.
Further, the original 2 which has been read on both sides is inverted by the original front / reverse inverting unit 8 downstream of the original reading unit 6, and the original is read in order to invert the original even though the original is not read as in the related art. Since the document 6 is not passed through, the damage to the document 2 can be reduced, and the dirt attached to the glass 60 of the document reading unit 6 can be reduced. And the first
With a simple structure by switching the transport direction switching means 55 and the second transport direction switching means 56, the next document 2 is immediately read from the second transport path B to the document reading section 6 of the third transport path C.
And the first side can be read, and the reading time of both sides of the document 2 can be reduced.

[0064]

As described above, according to the first aspect of the present invention, the original, which has been read on both sides of the first and second surfaces, is inverted by the original front / back reversing section downstream of the original reading position on the circulation path. The next document is immediately sent to the document reading position and the first side can be read.
The reading time of both sides of the document can be reduced. Also,
The original that has been read on both sides is inverted by the original upside-down part downstream from the original reading position, and it does not pass through the original reading position despite the fact that the original is not read as in the conventional case. In addition to reducing the damage to be applied, dirt at the document reading position can be reduced, and handling is easy.

Further, instead of detecting the width of the original and the time required to pass through the sensor as in the prior art, the original size is not determined, but the original size is detected in a mounted state, and the image formation start signal is received to detect the original size. Since the setting of the memory area for storing the original image information, the selection of the transfer paper, and the feeding of the original for reading the original image are controlled based on the obtained original size information, the image formation can be started in a short time.

According to the second aspect of the present invention, since the size detecting means is composed of the document width detecting means and the length detecting means, the size of the document placed on the sheet feeding table is set. , Can be detected simply and reliably.

According to the third aspect of the present invention, a paper discharge tray is provided below the paper feed tray, and a document reversing section is provided below the paper discharge tray. By positioning the paper feeder on the same side as the document reading position in the circulation path and devising the layout of the paper feed tray, the output tray, and the document reversing unit, the size of the apparatus can be increased even if the document reversing unit is provided. Therefore, the reading time of both sides of the document can be reduced.

According to the fourth aspect of the present invention, the original, which has been read on both sides of the first and second surfaces, is inverted by the original front / back inverting portion downstream of the original reading position on the circulation path, and is discharged to the discharge tray. Then, the next original is immediately sent to the original reading position and the first side can be read, and the reading time of both sides of the original can be reduced. In addition, the original that has been read on both sides is inverted by the original upside down unit downstream of the original reading position, so that the original does not pass through the original reading position despite the fact that the original is not read as in the related art. In addition to reducing the damage to the original, the dirt at the original reading position can be reduced and the handling is easy.

Further, instead of detecting the width of the original and the time required to pass through the sensor as in the prior art, the original size is not determined, but the size of the original is detected and the image formation start signal is received. Since the setting of the memory area for storing the original image information, the selection of the transfer paper, and the feeding of the original for reading the original image are controlled based on the obtained original size information, the image formation can be started in a short time.

According to the fifth aspect of the present invention, it is possible to easily and reliably detect the size of the original placed on the paper feed tray in a state where it is placed.

According to the sixth aspect of the present invention, when the double-sided reading mode is selected, the next original is immediately circulated by simple control by switching the first transport direction switching means and the second transport direction switching means. To the original reading position, and the first side can be read, and the reading time for both the first and second sides of the original can be reduced. In addition, since the original that has been read on both sides is inverted by the original upside down unit and discharged to the output tray, the original reading position is set to be inverted even though the original is not read as in the related art. , The damage to the document can be reduced, and the dirt attached to the glass of the document reading section can be reduced, so that the handling is easy.

According to the seventh aspect of the present invention, the original is placed on the paper feed tray such that the surface of the first page is the top surface, and the surface of the first page of the original placed on the paper feed tray is Are conveyed so as to be sequentially read from the image, and the original after the reading of both sides of the image is discharged to be sequentially stacked face down on the output tray, so that the front side of the original is on the upper side As described above, the user can place an image on the paper feed table, so that the user can perform image formation while checking the image on the front surface of the document, and
Since it is possible to discharge the original, for which the reading of the double-sided image has been completed, onto the paper discharge tray in a state where the pages are arranged in order, the operability is significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an automatic document feeder.

FIG. 2 is a plan view of a document feeding unit.

FIG. 3 is a schematic diagram illustrating driving and sensor arrangement of the automatic document feeder.

FIG. 4 is a control block diagram of the image forming apparatus.

FIG. 5 is an operation timing chart for reading both sides of a document by the automatic document feeder.

FIG. 6 is a flowchart of document reading.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 automatic document feeder 2 document 3 document feeding unit 6 document reading unit 7 paper output tray 8 document reversing unit 10 paper feed table 55 first transport direction switching unit 56 second transport direction switching unit 61 document reading unit 100 image forming Device body P1 Document reading position PS1 Circulation path PS2 Supply path PS3 Ejection path PS4 Switchback carry-in path PS5 Switchback carry-out path S Size detection means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masanobu Kono 2970 Ishikawacho, Hachioji-shi, Tokyo In-house Konica Co., Ltd. (72) Inventor Mitsuru Nagoshi 2970 Ishikawa-cho, Hachioji-shi, Tokyo In-house Konica Incorporated (72) Inventor Hisao Hosoya 2970 Ishikawa-cho, Hachioji-shi, Tokyo In-house (72) Inventor Satoru Endo 2970 Ishikawa-cho, Hachioji-shi, Tokyo In-house Konica Incorporated

Claims (7)

[Claims] A sheet feeder on which an original is placed; a discharge tray on which the original after reading is loaded; a circulation path having an original reading position; and an original supplied from the paper supply to the circulation path. Supply path, a discharge path for discharging the read document from the circulation path to the paper discharge tray, a switchback loading path for loading the document from the circulation path, and switching back the loaded document. A document reversing unit for reversing the front and back of a document, comprising a front and back reversing means for reversing the document and a switchback carry-out path for carrying the document reversed to the circulation path, the circulation path and the switchback carry-in path. First transport direction switching means provided at a connection portion with the first transport direction for switching the transport direction of the document to the circulation path or the switchback carry-in path; An automatic document feeder provided at a connection portion of the document feeder and a second transport direction switching means for switching a transport direction of the document to the circulation path or the discharge path, and a document image at a document reading position of the circulation path. An original reading means for reading information, a one-sided reading mode for reading the first side of the original, and a two-sided reading mode for circulating the original by activating the reverse side of the original and reading the first and second sides. And a document reading mode selecting means, and an image forming apparatus main body comprising control means for controlling image formation, the image forming apparatus comprising: Size detecting means for detecting a size is provided, and the control means receives an image formation start signal and detects document size information detected by the size detecting means. Setting of the memory area for storing the original image information on the basis of the selection of the transfer sheet, and an image forming apparatus and controls the feeding of the document for the original image reading. 2. An image forming apparatus according to claim 1, wherein said size detecting means comprises a document width detecting means and a length detecting means. 3. A paper discharge tray is provided at a lower portion of the paper feed tray, and the document front and back reversing portion is provided at a lower portion of the paper discharge tray. The paper feed tray, the paper discharge tray, and the document front and back reversing portion are provided. The image forming apparatus according to claim 1, wherein the circulation path is located on the same side as a document reading position. 4. A paper feed tray on which a document is placed, a paper discharge tray on which a document after reading is loaded, a circulation path having a document reading position, and a document supplied from the paper supply tray to the circulation path. Supply path, a discharge path for discharging the read document from the circulation path to the paper discharge tray, a switchback loading path for loading the document from the circulation path, and switching back the loaded document. A document reversing unit for reversing the front and back of a document, comprising a front and back reversing means for reversing the document and a switchback carrying-out path for carrying the document reversed to the circulation path, the circulation path and the switchback carrying path. First transport direction switching means provided at a connection portion with the first transport direction for switching the transport direction of the document to the circulation path or the switchback carry-in path; An automatic document feeder provided at a connection portion of the document feeder and a second transport direction switching means for switching a transport direction of the document to the circulation path or the discharge path, and a document image at a document reading position of the circulation path. An original reading means for reading information, a one-sided reading mode for reading the first side of the original, and a two-sided reading mode for circulating the original by activating the reverse side of the original and reading the first and second sides. A document reading mode selecting means, and an image forming apparatus main body comprising: a control means for controlling image formation. A size detection unit for detecting the size of the document; a document detected by the size detection unit upon receiving an image formation start signal from the control unit; Method of controlling an image forming apparatus, wherein setting memory area for storing original image data based on the size information, the selection of the transfer sheet, and to control the feeding of the document for the original image reading. 5. A control method for an image forming apparatus according to claim 4, wherein said size detecting means comprises a document width detecting means and a length detecting means. 6. When the double-sided reading mode is selected by the document reading mode selecting means, the control means reads the document whose first surface image has been read at the document reading position of the circulation path. The first transport direction switching means is controlled so as to be transported to the reversing unit, and the second document is transported out of the original transported to the original front / reverse inversion unit to the circulation path and transported to the original reading position with the front / back reversed. Controlling the transport direction switching means, and controlling the first transport direction switching means so that the original having the image read on the second side at the original reading position is again loaded into the original front / back inversion section; And controlling the second transport direction switching means so as to discharge the document re-conveyed to the paper feeding section to the circulation path and then discharge the document to the paper discharge tray. Method of controlling an image forming apparatus of claim 5, wherein. 7. An original is placed on the paper feed tray such that the surface of the first page is the uppermost surface, and an image on the surface of the first page of the original placed on the paper feed tray is sequentially arranged. 7. The image forming apparatus according to claim 6, wherein the original that has been conveyed so as to be read and has been read on both sides of the image is discharged so as to be sequentially stacked face down on the discharge tray. How to control the device.