JP2001022138A - Automatic document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select different read-out mode between two cases of putting value on productivity and putting value on an image quality. SOLUTION: This device 10, is an automatic document feeder provided with a first read-out part 72 for reading the running document and a second read-out part 74 for optical system scanning, and mounted on the image reading device 70 capable of reading by the resolving power of at least 2 levels. Meanwhile, the device respectively provided with first document feeding parts 32, 34, and 36 on the positions opposite to the first read-out part 72, and provided with a second document feeding part 46 on the position opposite to the second read- out part 74, is making the document through mode reading the running document image by transporting the document at the constant speed by the first document transporting parts 32, 34 and 36, and the document scanning mode reading the document image by optical scanning by letting the document stopped on a specified position in the second document transporting part 46 possible to be selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder which is mounted on an image reading device and feeds documents one by one to an image reading position.

[0002]

2. Description of the Related Art A document set on a document reading platen is read by a scanner, and the read image is read by a CC.
In a digital copier capable of being converted into an electric signal by D and stored in a memory as image data, the image data can be repeatedly printed or processed.
The reading operation for the same document in the image reading section is performed only once irrespective of the number of prints, and there is no need to repeat the reading operation for the set number unlike an analog copying machine. Therefore, in the digital copying machine, since it is not necessary to consider the return time of the scanner with respect to the print paper feed interval, from the viewpoint of image quality, noise reduction and power saving, the paper feed interval is reduced. As short as possible to slow down the system speed.

There are generally the following two types of automatic document feeders mounted on digital copying machines as described above. First, there is an automatic document feeder (hereinafter, referred to as ADF) of a type in which set documents are sequentially supplied one by one onto a platen and stopped at an exposure position. When the ADF is mounted, the original is set at a predetermined position on the platen by the ADF, and the optical system scans the original to read the original image. The second is an automatic document feeder (hereinafter referred to as FDH) of a type in which the set documents are sequentially supplied one by one to an image reading unit, and are conveyed at a constant speed on an optical system fixed to the image reading unit. ). When the FDH is mounted, the optical system is fixed to the image reading unit, and reads an original image conveyed thereon at a constant speed.

[0004]

When the above-mentioned ADF is used, since the paper feeding interval (that is, the time allowed for the ADF original exchange) is short, the ADF original exchange cannot be completed in time, so The productivity (hereinafter, referred to as one-to-one productivity) when copying one document per document is reduced. In order to increase the one-to-one productivity, it is necessary to shorten the document exchange time of the ADF, that is, to increase the operation speed of the ADF. An increase in the speed of the ADF leads to a reduction in document feeding performance and conveyance performance, an increase in the risk of document damage, an increase in operation noise, and the like. Further, from the point of view of the image reading system, the time allowed for the return operation of the scanner is short because the sheet feeding interval is short, and a high-speed operation is required. If a high-output motor is used as a drive source to operate the scanner at high speed, the size and cost of the apparatus will increase.

On the other hand, when the FDH is used, it is not necessary to stop the original at the time of exposure, so that the processing time of the original per sheet is shortened, and the productivity of one to one can be improved. In addition, since the document conveyance speed may be lower than the ADF (basically, equivalent to the system speed), it is possible to suppress the deterioration of the document feeding performance and the conveyance performance and the occurrence of document damage. However, in the sheet-through system, the constant speed of document conveyance directly affects an image. In an FDH that conveys various types of originals, it is difficult to achieve the same conveyance performance for all the originals. Therefore, the image quality of some originals is lower than that of an image read by an optical system. May be inferior. Therefore, it is necessary to manually read one image at a time for a document that emphasizes image quality.

That is, when the ADF system is employed, the productivity of any document decreases, and the FD
When the H system is adopted, high productivity can be achieved, but there is a problem that image quality is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder which allows a user to select a document reading operation by panning and a document reading operation by scanning an optical system.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a first reading section for panning a document and a second reading section for scanning an optical system. An automatic document feeder mounted on an image reading device capable of reading at a resolution, comprising a first document feeder at a position facing the first reading unit and a second document feeding unit at a position facing the second reading unit. A first document transporter, a document through mode in which the first document transporter conveys the document at a constant speed, and reads a document image by panning, and an optical system in which the second document transporter stops the document at a predetermined position and A document scan mode for reading a document image by a system scan can be selected.

In the automatic document feeder of the present invention, it is possible to determine whether to operate in the original through mode or the original scan mode based on the designated resolution, or to use the original through mode or the original through mode depending on the material of the original. Which of the document scanning modes is to be operated may be determined. When a manual paper feed unit is provided, all documents set in the manual paper feed unit may be processed in the document scan mode.

[0010]

According to the automatic document feeder of the present invention, for example, by selecting a reading mode according to a designated resolution or a material of a document, the reading mode can be selectively used between the case where importance is placed on image quality and the case where productivity is emphasized. Can be 1
The copying operation can be completed in a time corresponding to a desired image quality without uniformly lowering the productivity of one-to-one. In addition, the range of the original to be compensated in the original through mode and the read image quality can be limited, and a precise transport mechanism for enabling all originals to be transported at a constant speed in the original through mode is unnecessary. Therefore, the size and cost of the device can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the automatic document feeder 10 according to the present invention is mounted on an image reading device 70.

On the upper part of the image reading device 70, there is provided a slit glass 7 constituting a first reading section for panning a document.
2 and a platen glass 74 constituting a second reading unit for scanning the optical system. Image reading device 70
Illuminating lamp 76 for exposing the original on platen glass 72 or slit glass 74, reflection mirrors 78, 80 for polarizing the optical path of the light reflected from the original.
82, a lens 84 having a focusing and zooming function, a CCD sensor 86 for receiving the reflected light and converting it into image data,
A control unit 88 for storing the converted image data and controlling the driving of the optical system, a motor 90 for driving the optical system,
In addition, a shading correction plate 92 is provided at an end of the lower surface of the platen glass 72 to correct the sensitivity variation of the CCD sensor 86.

The illumination lamp 76, the reflection mirrors 78, 80,
The optical system composed of the lens 82 and the lens 84 is slidable in the direction of the arrow 94 by driving the motor 90. The control unit 88 is electrically connected to an external input device 96 such as a personal computer, for example, and is configured to input information such as a reading resolution and a material of a document. Further, a substantially central portion of the slit glass 72 is located at the reading position A, and the platen glass 7 on the opposite side of the shading correction plate 92.
2 are located at the document reference position B.

On the other hand, the automatic document feeder 10 generally includes a paper feeder, a first document feeder, and a second document feeder. The paper feeding unit includes a paper feeding tray 1 on which a document D is stacked.
2, a paper feed roller 14 for sequentially feeding the originals stacked on the paper feed tray 12 from the top, a pair of sabaki rollers 16 for separating the fed originals one by one, and an original sent from the pair of sabaki rollers 16 And a guide pair 18 for guiding the The paper feeding unit includes a manual tray (manual paper feeding unit) 20 and a paper feed roller 22 that feeds a document set on the manual tray 20. further,
The paper feed unit includes a document empty sensor 24 for detecting whether a document is present on the paper feed tray 12, and a paper feed sensor 26 for detecting an edge of the document immediately after the pair of rollers 16.
A manual sensor 28 for detecting that a document is set on the manual feed tray 20, and a registration sensor 30 for detecting an end of the document near the exit of the guide pair 18.

The first document feeder is provided at a position facing the slit glass 72 of the image reading device 70. The press-contact guide 32 is disposed with a slight gap between the slit glass 72 and the slit glass 72 such that a document can pass therethrough. On both sides of the pressing guide 32, a first reading roller pair 34 and a second reading roller pair 36 for transporting the document D at a constant speed via between the slit glass 72 and the pressing guide 32 are arranged. The first document conveying section is constituted by the press-contact guide, the first reading roller pair 34 and the second reading roller pair 36. In the vicinity of the second reading roller pair 36, a document path switching claw 38 that is rotatable by driving a solenoid (not shown) or the like is provided. The original D sent from the second reading roller pair 36
Are discharged onto a first discharge tray 44 via a guide pair 40 and a first discharge roller pair 42.

The platen glass 7 of the image reading device 70
An endless transport belt 46 constituting a second document transport unit is stretched between two rollers 48 and 50 in a position facing the roller 4 so as to be rotatable in the direction of arrow 52. The document D transported on the platen glass 74 by the rotating transport belt 46 is discharged onto a second discharge tray 56 via a second discharge roller pair 54.

The automatic document feeder 10 includes a control unit 58.
It has. The control unit 58 is electrically connected to the control unit 88 of the image reading device 70 so that information can be exchanged. Further, the control unit 58 controls each of the sensors 24, 26, 2
In addition to receiving signals from the control units 8 and 30, the rollers, the roller pair, the conveyance belt, and the document path switching claw are driven and controlled.

The automatic document feeder 10 is hingedly connected to the image reading device 70 on the rear side of the schematic diagram shown in FIG. 1, so that the entire automatic document feeder 10 except for the second paper discharge tray 56 can be opened. As a result, the platen glass 74
The original can be set manually on top.

Next, the operation of the automatic document feeder 10 and the image reading device 70 having the above-described configurations will be described with reference to FIG.
This will be described with reference to FIG. Control unit 8 of image reading device 70
When an image reading command and various reading conditions (image quality information, document size, etc.) are sent from the external input device 96, first, the document empty sensor 24 and the control unit 58 of the automatic document feeder (ADF) are sent to the control unit 58. Based on a signal from the manual feed sensor 28, it is confirmed whether or not the document D is set on the paper feed tray 12 or the manual feed tray 20 (S1). Here, the image quality information of the reading condition is, for example, a resolution of 600 dpi or 1200 dpi.

If the document D is not set on either the paper feed tray 12 or the manual feed tray 20 (N in S1)
O), the control unit 88 is placed on the platen glass 74 by hand.
First, the CCD sensor 86 reads the shading correction plate 92, and the CCD sensor 86 reads the original.
The variation of each pixel of the sensor 86 is corrected. Thereafter, the motor 90 is driven to drive the illumination lamp 76 and the reflection mirror 7.
The slides 8, 80 and 82 are slid and set at the document reference position B (S5). Then, the illumination lamp 76 and the reflection mirror 78 are moved in the direction of the arrow 94 at a predetermined speed V, and the reflection mirrors 80 and 82 are moved in the direction of the arrow 94 at a speed of V / 2, so that the optical path length is kept constant and the platen glass is moved. Of the original D on the original 74 (S
6).

On the other hand, when the document D is set on the paper feed tray 12 or the manual feed tray 20 (YE in S1).
S), the control unit 88 checks the image quality information (image quality mode) sent from the external input device 96 (S2), 600
In the case of reading at a resolution of dpi, a document through mode by moving a document is performed (S3), 1200 dpi
In the case of reading at the resolution of i, a document scanning mode by optical system scanning is executed (S4).

The document through mode is executed according to the procedure shown in FIGS. First, in the image reading device 70, the motor 90 is driven to move the illumination lamp 76 and the reflection mirror 78 to the reading position A of the slit glass 72 (S1).
0). Then, in the automatic document feeder 10, the uppermost document D among the documents D stacked on the paper feed tray 12 with the document surface facing upward is fed downstream by rotation of the paper feed roller 14. (S11). The fed document D is separated one by one by the rotating sub-roller pair 16, and only one document D is transported downstream in the transport direction of the sub-roller pair 16. The document D fed by the paper feed sensor 26
When the leading end is detected, the rotation of the feed roller 14 is stopped.

The leading edge of the document D conveyed from the pair of rollers 16 via the pair of guides 18
4, the Sabaki roller pair 16 presses the leading end of the document D against the nip portion of the stopped first reading roller pair 34 to form an appropriate amount of loop on the document D, as shown in FIG. After forming and holding, the driving is stopped. Thereby, the leading end of the document D is aligned and the skew is corrected (S12).

Thereafter, the first reading roller pair 34 is driven to rotate, and the conveyance of the document toward the reading position A is started (S13). At the same time, the control unit 58 of the automatic document feeder 10 transmits a reference signal for setting a timing at which the image reading device 70 starts image reading to the control unit 88 of the image reading device 70.

The image reading device 70 starts reading an image at a resolution of 600 dpi at the timing when the leading edge of the document D reaches the reading position A based on the reference signal (S14). The illumination lamp 76 and the reflection mirror 78 are fixed at the reading position A, and are exposed and scanned when the document D passes over the slit glass 72, and the reflected light is transmitted through the reflection mirrors 80 and 82 and the lens 84. And read by the CCD sensor 86. The document D is transported at a constant speed from the time when the leading edge reaches the reading position A to the time when the trailing edge passes. Then, as shown in FIG. 4B, the document D that has passed the reading position A is guided to the second reading roller pair 36 by the switching claw 38.

The original D that has been read is shown in FIG.
As shown in (c) and (d), the sheet is discharged onto the first sheet discharge tray 44 by the first sheet discharge roller pair 42 (S15).
During the discharge of the original, it is checked whether the next original D is on the paper feed tray 12 (S16). If there is the next original D, the rear end of the original D being read has passed the position facing the registration sensor 30. At this point, the feeding of the next original D is started. As described above, until there are no more documents on the paper feed tray 12, the above-described steps S11 to S1 are performed.
Step 6 is repeated.

Next, the document scanning mode is shown in FIG.
It is executed according to the procedures shown in FIGS. First, in the automatic document feeder 10, the uppermost original D among the originals D stacked on the paper feed tray 12 with the original surface facing upward is fed downstream by rotation of the paper feed roller 14. (S20).
The fed document D is rotated by the rotating pair 16
One sheet D is conveyed downstream of the pair of rollers 16 in the conveying direction. When the feed sensor 26 detects the leading end of the fed document D, the rotation of the feed roller 14 is stopped.

The leading end of the document D conveyed from the pair of rollers 16 through the pair of guides 18
As shown in FIG. 6A, the pair of Sabaki rollers 16 presses the leading end of the document D against the nip portion of the stopped first reading roller pair 34 to form an appropriate amount of loop on the document D. After forming and holding, the driving is stopped. Thereby, the leading end of the document D is aligned and the skew is corrected (S21).

Then, as shown in FIG. 6B, a solenoid (not shown) is turned on to rotate the switching claw 38 counterclockwise (S22). In this state, the first reading roller pair 34 is rotated to transport the document D to the transport belt 46 through the gap between the slit glass 72 and the press-contact guide 32, and when the next document D is on the paper feed tray 12. Starts feeding the next original D when the rear end of the original D passes the position facing the registration sensor 30 and transports the original D to the first reading roller pair 34 (S23).

As shown in FIG. 6C, the transport belt 46
Document D conveyed on platen glass 74 by rotation of
When the sheet reaches a position separated by a predetermined distance from the document reference position B, the rotation of the conveyance belt 46 is stopped (S24). At this time, the control unit 58 of the automatic document conveyance device 10 controls the control unit 88 of the image reading device 88. To notify that document D is set at a predetermined position on platen glass 74
Send a signal. Then, the solenoid that has rotated the switching claw 38 is turned off to return to the original state, that is, the state in which the document D is guided to the second reading roller 36 (S25).

When the control unit 88 of the image reading device 70 receives the DSET signal, the CCD sensor 86 first reads the shading correction plate 92 to correct the variation of each pixel of the CCD sensor 86. After that, the illumination lamp 76 and the reflection mirror 7 are driven by driving the motor 90.
The slides 8, 80, and 82 are slid and set at the document reference position B (S26). Then, as shown in FIG. 7A, the illumination lamp 76 and the reflection mirror 78 are driven at a predetermined speed V.
To move in the direction of arrow 94,
By moving 0, 82 in the direction of arrow 94 at a speed of V / 2, the optical path length is kept constant, and an image of document D set on platen glass 74 is read at a resolution of 1200 dpi (S27).

When the image reading is completed, the control section 88 of the image reading apparatus 70 sends a SCEND signal notifying the reading end to the control section 58 of the automatic document feeder 10. As a result, as shown in FIG. 7B, the automatic document feeder 10 rotates the feed belt 46 to move the document D on the platen glass 74 onto the second discharge tray 56 by the second discharge roller pair 54. (S28).

Next, it is checked whether there is a next original D waiting just before the first reading roller pair 34 (S29).
If the next original D is present, it is transported to a predetermined position on the platen glass 74 and the image is read similarly. As described above, until the document D on the paper feed tray 12 is exhausted, the above-described steps S22 to S22 are performed.
Repeat step 29.

As described above, according to the automatic document feeder 10 of the present embodiment, either the reading in the document through mode or the reading in the document scan mode can be selected according to the resolution designated by the user. The reading mode can be selectively used between the case where the image quality is emphasized and the case where the productivity is emphasized, and the copy operation can be completed in a time corresponding to the desired image quality without uniformly lowering the one-to-one productivity. . In addition, the range of the original to be compensated in the original through mode and the read image quality can be limited, and a precise transport mechanism for enabling all originals to be transported at a constant speed in the original through mode is unnecessary. Therefore, the size and cost of the device can be reduced.

In the above embodiment, the original through mode or the original scan mode is selected according to the resolution specified by the user. However, the original through mode or the original scan mode is selected according to the material of the original. You may. When the reading mode is selected according to the material of the document, a process as shown in FIG. 8 is executed.

When an image reading command and various reading conditions (document material, document size, etc.) are sent from the external input device 96, the control unit 88 of the image reading device 70 first controls the automatic document feeder (ADF). 58, the document empty sensor 24 and the manual feed sensor 28
Then, it is confirmed whether or not the document D is set on the paper feed tray 12 or the manual feed tray 20 based on the signal from (S30). Here, the original material of the reading conditions is a normal original such as plain paper or a special original such as thick paper.

If the original D is not set on either the paper feed tray 12 or the manual feed tray 20 (NO in S30), the control unit 88 determines that one original is set on the platen glass 74 by hand. First, the CCD sensor 86 reads the shading correction plate 92, and
The variation of each pixel of the D sensor 86 is corrected. afterwards,
The motor 90 is driven to slide the illumination lamp 76 and the reflection mirrors 78, 80, and 82 so that the original reference position B
(S34). Then, the illumination lamp 76 and the reflection mirror 78 are moved in the direction of the arrow 94 at a predetermined speed V, and the reflection mirrors 80 and 82 are moved in the direction of the arrow 94 at a speed of V / 2, so that the optical path length is kept constant and the platen glass is moved. The image of the document D on the document 74 is read (S35).

On the other hand, when the document D is set on the paper feed tray 12 or the manual feed tray 20 (YE in S30).
S), the control unit 88 checks the original material sent from the external input device 96 (S31), executes the original through mode for a normal original (S32), and sets the original scan mode for a special original. Execute (S34). The processes in the document through mode and the document scan mode are described in FIGS.
The description is omitted because it is the same as that described with reference to. However, in this case, the image reading resolution of each mode may be the same or different.

If the reading mode is selected in accordance with the material of the document as described above, a reading operation with high productivity can be achieved for a normal document, and for a special document, there is little bending of the document being conveyed. A reading operation with less risk can be achieved. In addition, it is possible to limit the range of the original to be compensated in the original through mode,
As in the related art, since a precise transport mechanism for enabling all originals to be transported at a constant speed in the original through mode is not required, the apparatus can be reduced in size and cost.

Next, an embodiment in which all documents set on the manual feed tray 20 are processed in the document scan mode will be described. The processing in this case is executed as shown in FIG.

When an image reading command and various reading conditions (image quality information, document size, etc.) are sent from the external input device 96, the control unit 88 of the image reading device 70 first controls the automatic document feeder (ADF). 58, the document empty sensor 24 and the manual feed sensor 28
Then, it is confirmed whether or not the document D is set on the paper feed tray 12 or the manual feed tray 20 based on the signal (S40). Here, the image quality information of the reading condition is, for example, a resolution of 600 dpi or 1200 dpi.

When the document D is not set on either the paper feed tray 12 or the manual feed tray 20 (NO in S40), the control unit 88 determines that one document is set on the platen glass 74 by hand. First, the CCD sensor 86 reads the shading correction plate 92, and
The variation of each pixel of the D sensor 86 is corrected. afterwards,
The motor 90 is driven to slide the illumination lamp 76 and the reflection mirrors 78, 80, and 82 so that the original reference position B
(S55). Then, the illumination lamp 76 and the reflection mirror 78 are moved in the direction of the arrow 94 at a predetermined speed V, and the reflection mirrors 80 and 82 are moved in the direction of the arrow 94 at a speed of V / 2, so that the optical path length is kept constant and the platen glass is moved. The image of the original D on the image 74 is read (S56).

When the document D is set in the automatic document feeder 10 (YES in S40), whether the document D is set on the paper feed tray 12 or the manual tray 2
Original empty sensor 24
And from the output signal of the manual feed sensor 28 (S4
1).

When the document D is set on the manual feed tray 20 (YES in S41), the manual feed roller 22
Is rotated to feed the uppermost original D to the downstream side in the transport direction (S45). When the registration sensor 30 detects the leading end of the document D fed from the manual feed tray 20, the manual feed roller 22 presses the leading end of the document D against the nip portion of the stopped first reading roller pair 34. Manuscript D
After forming and holding an appropriate amount of loop, the driving is stopped. Thus, the leading end of the document D is aligned and the skew is corrected (S46).

Then, a solenoid (not shown) is turned on to rotate the switching claw 38 counterclockwise (S4).
7). In this state, the first reading roller pair 34 is rotated to transport the document D to the transport belt 46 through the space between the slit glass 72 and the press-contact guide 32, and when the next document D is on the manual feed tray 20. When the trailing end of the document D being conveyed has passed the position facing the registration sensor 30, the feeding of the next document D starts, and the first reading roller pair 3
4 (S48).

When the document D conveyed on the platen glass 74 by the rotation of the conveyance belt 46 reaches a position separated by a predetermined distance from the document reference position B, the rotation of the conveyance belt 46 is stopped (S49), and the automatic document The control unit 58 of the transport device 10 sends a DSET signal to the control unit 88 of the image reading device 88 to notify that the document D has been set at a predetermined position on the platen glass 74. Then, the solenoid that has rotated the switching claw 38 is turned off to return to the original state, that is, the state in which the document D is guided to the second reading roller 36 (S50).

When the control unit 88 of the image reading device 70 receives the DSET signal, the CCD sensor 86 first reads the shading correction plate 92 to correct the variation of each pixel of the CCD sensor 86. After that, the illumination lamp 76 and the reflection mirror 7 are driven by driving the motor 90.
The slides 8, 80, and 82 are slid and set at the document reference position B (S51). Then, the illumination lamp 76 and the reflection mirror 78 are moved in the direction of the arrow 94 at a predetermined speed V, and the reflection mirrors 80 and 82 are moved in the direction of the arrow 94 at a speed of V / 2 so that the optical path length is kept constant. The original D set on the glass 74 is
An image is read at a resolution of 00 dpi (S52).

When the image reading is completed, the control section 88 of the image reading apparatus 70 sends a SCEND signal for notifying the completion of the reading to the control section 58 of the automatic document feeder 10. As a result, the automatic document feeder 10 rotates the feed belt 46 to feed the original D on the platen glass 74.
Is discharged onto the second discharge tray 56 by the second discharge roller pair 54 (S53).

Subsequently, it is checked whether there is a next original D waiting just before the first reading roller pair 34 (S54).
If the next original D is present, it is transported to a predetermined position on the platen glass 74 and the image is read similarly. As described above, until the document D on the manual feed tray 20 is exhausted, the processes in S47 to S47 are repeated.
Step S54 is repeated.

When the document D is set on the manual feed tray 20, the steps S45 to S54 may be automatically executed after a predetermined time.

On the other hand, when the document D is set on the paper feed tray 12 (NO in S41), the control unit 88 checks the image quality information (image quality mode) sent from the external input device 96 (S42). ), In the case of reading at a resolution of 600 dpi, a document through mode is executed (S43),
In the case of reading at a resolution of 1200 dpi, a document scan mode is executed (S44). The processes in the document through mode and the document scan mode are the same as those described with reference to FIGS.

As described above, the manual feed tray 20
If all the originals set in the original are scanned in the original scan mode, the original transport path from the manual feed tray 20 to the second output tray 56 is almost straight, so that the originals are special originals such as thick paper or thin paper. In some cases, or when the document is an important document that the user does not want to damage during the conveyance process, the risk of document damage can be reduced.

In the above description, the image quality information and the document material information are provided from the external input device. However, the operation panel and the like for inputting such information to the automatic document feeder 10 and the image reading device 70 are provided. Input means may be provided.

It is apparent that the automatic document feeder of the present invention can be applied to a digital copying machine in which an image reading section and an image forming section are integrated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image reading apparatus and an automatic document feeder according to the present invention mounted on the image reading apparatus.

FIG. 2 is a flowchart illustrating processing of an image reading operation.

FIG. 3 is a flowchart illustrating processing in a document through mode.

FIG. 4 is a diagram illustrating a state of transporting a document in a document through mode in a stepwise manner.

FIG. 5 is a flowchart illustrating processing in a document scan mode.

FIG. 6 is a diagram illustrating a state in which a document is transported in a document scan mode in a stepwise manner.

FIG. 7 is a diagram showing the state of transporting the document in the document scanning mode in a stepwise manner, and is a continuation of FIG. 6;

FIG. 8 is a flowchart showing processing when an image reading mode is selected according to the material of a document.

FIG. 9 is a flowchart showing processing when reading all documents set on a manual feed tray in a document scan mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Automatic document feeder, 12 ... Paper feed tray, 14 ... Paper feed roller, 32 ... Press contact guide, 34 ... 1st reading roller pair, 36 ... 2nd reading roller pair, 46 ... Conveying belt, 58 ... Control part, 70 image reading device, 72 slit glass, 74 platen glass, 88 control unit,
96 external input device

Claims (4)

[Claims] A first reading unit for panning a document and a second reading unit for scanning an optical system;
An automatic document feeder mounted on an image reading device capable of reading at a step resolution, comprising a first document feeder at a position facing the first reading unit and a position facing the second reading unit. A document through mode in which a second document feeder is provided, wherein the first document feeder conveys a document at a constant speed and reads a document image by panning, and stops the document at a predetermined position in the second document feeder. An automatic document feeder, wherein a document scan mode for reading a document image by optical system scanning can be selected. 2. The automatic document feeder according to claim 1, wherein a mode of operation in a document through mode or a document scan mode is determined according to a designated resolution. 3. The automatic document feeder according to claim 1, wherein a mode of operation in a document through mode or a document scan mode is determined according to a material of the document. 4. The automatic document feeder according to claim 1, further comprising a manual paper feed unit, wherein all documents set in the manual paper feed unit are processed in a document scan mode.