JP2001053938A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve throughput by devising shading operation when reading an image with a sheet through system. SOLUTION: An operation parameter required for shading operation or reading operation is set (S901), and shading operation is performed (S902). After shading operation, reading operation is started (S903) and the end of reading is waited (S904). After the end of reading (S905), shading operation is performed (S906). When shading operation is finished (S907) and the next reading is prepared (S908), an operation parameter is set (S909), reading operation is started (S910) and the end of reading is waited (8911). After the end of reading (S912), shading operation is performed (S913). Thus, throughput in continuous reading of plural images is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus having a sheet-through type document reading function used for a copying machine, a facsimile, a scanner, and the like, and an image forming apparatus having such an image reading apparatus.

[0002]

2. Description of the Related Art In a conventional sheet-through type reading apparatus, a white plate reading operation (shading) must be performed before reading a document, and a loss of time due to movement of a carriage to the white plate has been pointed out before. Was. To increase the reading throughput, it is conceivable to reduce the number of shadings. However, since the shading waveform changes with the lighting time of the lamp, it is desirable to perform the shading operation every time a document is read. In order to deal with such a problem, for example, Japanese Patent Application Laid-Open Nos. 8-9-1116 and 9-24739 are disclosed.
The invention disclosed in Japanese Patent Application Publication No. 5 (JP-A) No. 5 is known.

In Japanese Patent Application Laid-Open No. Hei 8-9116, two white reference plates are provided, and original images read in a first original reading mode for reading a stacked original and in a second original reading mode for reading a conveyed original are photoelectrically converted. The photoelectric conversion from the optical signal to the electric signal is performed by using the element, and the shading correction in the first original reading mode is performed by using the shading waveform obtained by reading the first white reference plate, and in the second original reading mode. Is disclosed using a shading waveform corrected based on data obtained by reading the second white reference plate.

Japanese Patent Application Laid-Open No. 9-247395 discloses that the reading of the white reference plate by the contact type reading means which is performed before reading the second and subsequent originals is performed when the rear end of the previous original is in close contact with the white reference plate. It is disclosed that the operation is performed at a predetermined timing after the document is separated from the mold reading unit or at a predetermined timing before the leading edge of the document comes into contact with the white reference plate.

[0005]

The problem to be solved by the invention
No. 9116 discloses a method of providing two white reference plates. However, providing two white reference plates increases the number of components and the number of assembling steps. JP-A-9-2473
In an image reading apparatus using a contact-type reading sensor as disclosed in Japanese Patent Publication No. 95, the relative position between the white reference plate and the contact-type reading sensor changes due to the thickness of the document, and is always kept under the same conditions. There is no guarantee that the white reference plate is being read. Further, the image reading apparatus using the contact type sensor has a configuration in which the reading position does not move, and a method of reading an original by both sheet through and pressure plate reading used in normal copying. It cannot be applied to things.

In the synchronization between the reading operation and the image output operation, for example, in a copying machine, it is necessary to synchronize the read original and the transfer paper, and the read and write operations are performed only when the transfer paper and the original are ready. Is started. In addition, in the case of FAX, there are cases where synchronization with a reading operation is necessary, such as preparation of a FAX application and synchronization of a document to be read. In any case, in order to increase the throughput, make effective use of the waiting time for synchronization, and
It is necessary to perform appropriate shading in order to obtain a high quality image.

On the other hand, when a user reads a plurality of originals and obtains shading data at the end of the reading, if the image quality is switched in the middle, it is necessary to switch the image quality immediately before the next reading and to obtain the shading data again. is there.

The present invention has been made in view of such a background, and an object of the present invention is to improve the throughput of an image reading apparatus capable of performing both sheet-through and pressure plate reading. .

Another object of the present invention is to provide an image forming apparatus capable of improving a throughput by performing a shading operation immediately after reading a document by a sheet-through method.

It is still another object of the present invention to provide an image reading apparatus and an image forming apparatus capable of retrieving shading data even when the throughput is sacrificed in the case of switching the image quality mode or the background removal mode. is there.

[0011]

According to a first aspect of the present invention, there is provided an image reading apparatus, comprising: an exposure optical system for reading a document conveyed at a constant speed on a platen;
A shading plate for correcting a white reference of the read image information, a traveling body for moving a reading position of the optical system in order to read the shading plate with the exposure optical system, and a traveling body for reading a document. The body is moved to a position facing the shading plate to perform a shading operation, and when the shading operation is completed, the traveling body is moved to a document reading position to perform reading of a document. And control means for moving a body to the position of the shading plate to perform a shading operation.

An image reading apparatus according to a second means includes an exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a white reference of the read image information, A traveling body that moves the reading position of the optical system to read the shading plate with the exposure optical system, and when the shading operation is performed by moving the traveling body after reading of the previous document is completed, the next document is read. The document is read without performing the shading operation by moving the traveling body before reading, and immediately after the reading is completed, the traveling body is moved to the shading plate position to perform the shading operation, and again, the reading position is set. And a control means for moving the traveling body.

In the image reading apparatus according to the third means, in the second means, when the exposure lamp is turned off before reading the next document, the traveling body is moved before reading the next document. Control means for causing the original to be read after performing the shading operation, moving the traveling body to the shading plate position to perform the shading operation immediately after the reading is completed, and moving the traveling body to the reading position again. Configuration.

In the image reading apparatus according to the fourth means, in the second means, when a predetermined time elapses until a next original reading operation, the traveling body is moved before the next original reading. After moving and performing the shading operation, read the original, immediately after the reading is completed, move the traveling body to the shading plate position to perform the shading operation, and again, control means for moving the traveling body to the reading position and Was provided.

An image reading apparatus according to a fifth aspect includes an exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a white reference of the read image information, A traveling body that moves a reading position of the optical system to read the shading plate with an exposure optical system, and a control unit that moves the traveling body to the position of the shading plate to perform a shading operation before reading a document. When the control unit switches the mode of the image quality of the previous document before the reading of the next document is started, the image quality setting is performed before reading the next document. And a shading operation is performed.

An image reading apparatus according to a sixth means includes an exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a white reference of the read image information, A traveling body that moves a reading position of the optical system to read the shading plate with an exposure optical system, and a control unit that moves the traveling body to the position of the shading plate to perform a shading operation before reading a document. When the control unit switches the background removal setting of the previous document by the start of reading of the next document when a plurality of documents are read, the background removal setting is performed before reading of the next document. To perform the shading operation.

Further, an image forming apparatus according to a seventh means is an image processing means for performing predetermined signal processing based on the image data input from the image reading device in the first to sixth means, And an image forming means for forming a visible image based on the image signal processed by the processing means.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1.1 Image Forming Apparatus (Digital Copier)
FIG. 1 is a schematic configuration diagram of a document feeder provided in a digital copying machine according to an embodiment of the present invention. An image forming apparatus generally refers to an entire apparatus (system) that processes an input signal as image data and outputs a visualized image based on the processed image data, such as a printer, a facsimile, and a copying machine. In this embodiment, only a part that forms an image as one function of the system refers to a so-called printer engine. This point corresponds to the image forming unit described in the claims.

First, referring to FIG. 2, a digital copying machine 1 according to the present embodiment includes a document feeding device 100, an image reading device 200, and an image forming device (printer engine) 3.
00 and a paper feeding device 400.

The details of the document feeder 100 will be described with reference to the schematic diagram of FIG. The document feeder according to the present embodiment has a fixed exposure position that is formed in a slit shape and has an exposure optical system fixed thereto. An automatic document feeder (sheet-through double-sided ADF) is used (hereinafter, also referred to as "ARDF").

In the ARDF 100 according to the present embodiment, a document feed tray 120 and a document discharge tray 123 are arranged above and below a platen 124 in two stages, and a reversing tray 121 is provided to provide a reversing path for reversing the document. Is provided between the document feed tray 120 and the discharge tray 123. The document feed tray 120 is provided with a document set sensor 193 for detecting the setting of a document, a bottom plate solenoid 192 for moving the document to a paper feed port, and a paper feed clutch 134 for driving a paper feed belt. Original set sensor 19
Reference numeral 3 denotes a transmission type sensor which detects the original with the filler pushed up by the original. The reversing switching claw 130 has a function of selecting whether to convey the document conveyed from the reading position 132 to the reversing tray 121 or to discharge the document to the discharge tray 123. The inversion switching claw 130 is operated by a solenoid.

Three sensors are provided to control the conveyance of the paper, which are a registration sensor 101, a paper discharge sensor 102, and a reversing tray sensor 103, respectively. The three sensors are reflection sensors with filters. Each of the following rollers is driven by two stepping motors 150. The sheet feeding belt 110, the separation roller 111 and the reversing roller 115 are connected to a reversing sheet feeding motor (possible for normal rotation and reverse rotation), a pull-out roller 112, and an auxiliary roller 113. The paper discharge roller 114 is driven by a transport motor (only one direction). The reversing roller 115 is provided with a torque limiter to cope with the case where the paper moves in the rotating direction.

In the document feeding apparatus 100, (a) a sheet feeding operation for reading the front side, (b) a sheet feeding operation for reading the back side, (c) a reversing sheet feeding operation of the document located at the registration position, D) feeding the original document to the registration position again, (e) discharging the original document after reading the image, and (f) discharging the original document from the registration position. It is possible. Hereinafter, each operation will be described.

(A) Feeding Operation for Reading the Front Side The original set on the original feeding tray 120 is picked up by the transport belt 110 and the separation roller 111.
The sheet is separated into one sheet and transported inside the ARDF. Thereafter, the sheet is conveyed by the pull-out roller 112, and stops after the registration sensor 101 detects the leading end of the document. At this time, the rotation direction of the reverse feeding motor is CW.

(B) Feeding Operation for Reading Back Side The original set on the original feeding tray 120 is picked up by the transport belt 110 and the separation roller 111.
The sheet is separated into one sheet and transported inside the ARDF. Thereafter, the pull-out roller 112 and the paper discharge roller 114
Transported by Then, after the paper discharge sensor 102 detects the leading end of the document, the inversion switching solenoid is turned on, the inversion switching claw 130 is switched to the lower side, and the transport path is opened to the inversion tray 121. As a result, the document is transported to the switchback point 131, and then stops.
At this time, the rotation direction of the reverse feeding motor is CW.

After the document stops at the switchback point 131, the rotation direction of the reversing paper feed motor is changed to CCW, and each roller is rotated in the reverse direction. in the meantime,
Turns the inversion switching solenoid off and turns the inversion switching claw 13
0 is switched to the upper side, the transport path is switched to the re-feed path 133, and the transport is performed to the position of the registration sensor 101. At this time, the rotation direction of the reverse feed motor is CCW.

(C) Reverse feed operation of the original at the registration position The original stopped at the position of the registration sensor 101 is conveyed in the direction of the original reading position 132, and after the discharge sensor 102 detects the leading end of the original, the reverse switching solenoid. Is turned on to switch the inversion switching claw 130 downward. As a result, the transport path is opened to the reversing tray 121, and after the trailing end of the document is detected by the paper discharge sensor 102, the document is transported to the switchback point 131 and stopped. At this time, the rotation direction of the reverse sheet feeding motor is CW.

After the document stops at the switchback point 131, the rotation direction of the reversing paper feed motor is changed to CCW and rotated in the reverse direction. In the meantime, the reversing switching solenoid is turned off, the transport path is switched to the re-feeding path 133 by the reversing switching claw 130, and the sheet is transported to the position of the registration sensor 101. At this time, the rotation direction of the reverse sheet feeding motor is CC.
W.

(D) Operation of Feeding the Original Having Read the Image Again to the Registration Position The original stopped at the registration sensor 101 is conveyed in the direction of the original reading position 132 and the original reading position 13
After the exposure is performed in step 2 and the paper discharge sensor 102 detects the leading edge of the document, the reverse switching solenoid is turned on, and the transport path is opened to the reverse tray 121 by the transport switching claw 130.
After the paper discharge sensor 102 detects the rear end of the document, the document is conveyed to the switch pack point 131 and stopped. At this time,
The rotation direction of the reverse sheet feeding motor is CW.

After the document stops at the switchback point 131, the rotation direction of the reversing paper feed motor is changed to CCW and rotated in the reverse direction. In the meantime, the reversing switching solenoid is turned off, the transport path is switched to the re-feeding path 133 by the reversing switching claw 130, and the sheet is transported to the position of the registration sensor 101. At this time, the rotation direction of the reverse sheet feeding motor is CC.
W.

(E) Operation of ejecting the original after reading the image The original stopped at the position of the registration sensor 101 is conveyed in the direction of the original reading position 132, and the original reading position 13
Exposure is performed in step 2, the reversing switching solenoid is turned off, and the conveyance path is opened to the document discharge tray 123 by the reversing switching claw 130, conveyed to the paper discharge port, and stopped. At this time, the rotation direction of the reverse feeding motor is CW.

(F) Operation for ejecting the original from the registration position The original stopped at the registration sensor 101 is conveyed in the direction of the original reading position 132, the inversion switching solenoid is turned off, and the conveyance path is ejected by the inversion switching claw 130. It is opened on the paper tray 123, conveyed to the paper discharge port, and stopped. At this time, the rotation direction of the reverse feeding motor is CW.

The image reading device 200 irradiates an original with an exposure lamp 201 as a light source, guides the reflected light from the original to a solid-state imaging device (CCD) 203 via a mirror 202, and converts the reflected light into an electric signal by the CCD 203. Devices having a function of performing necessary image processing are used.

1.2 Printer Engine In this embodiment, the image forming apparatus 300 employs a printer engine that forms an image by an electrophotographic method. However, the image forming apparatus 300 essentially converts an image sent by an electric signal into an electronic image. It is sufficient that the apparatus is formed on plain paper, heat-sensitive paper, or the like by means such as photo, heat, thermal transfer, and ink jet.
Although the configuration of an electrophotographic printer engine is known, it will be schematically described with reference to FIG.

In FIG. 2, an image signal read by the image reading device 200 and converted into image data is an LD.
The laser beam is applied to a (laser diode) unit 301, modulated, and incident on a polygon mirror 302 as a laser beam. The laser beam incident on the polygon mirror 302, which is rotated at a high speed by the polygon motor 303, is reflected by the writing mirror 304, enters the photosensitive drum 305, and forms a latent image by a known electrophotographic technique.
The formed latent image is developed with toner by the developing device 306, and the paper stopped at the position of the registration roller 401 is sent out at a timing with the toner-developed visible image,
The transfer unit 307 transfers the visible image on the photosensitive drum 305 onto paper. The transferred image is transferred to the fixing unit 308.
The sheet is heated and pressurized and fixed, and is discharged to an external discharge section formed by opening the internal discharge section 402 or the discharge cover 403. Note that a transport path switching claw 404 is provided to switch between the two, and an in-machine paper discharge unit 402
Is discharged by the transport roller 405.

The paper is stored in the first or second paper feed cassette 4.
The sheet is picked up from the sheets 06 and 407 by the sheet feed rollers 408 and 409 and sent to the position of the registration roller 401.

A transport roller 410 is provided on the path from the second paper feed cassette 407 to transport the paper. In addition,
In addition to the sheet cassettes 406 and 407, a manual door 411 is provided for performing manual sheet feeding. Thus, when performing manual paper feeding, the manual feeding door 411 can be opened and paper can be supplied from here.

1.3 Definition of Terms Before the description of the digital copying machine according to the present embodiment, terms used in the following description are defined so as not to be misunderstood.

"Extended functions" and "applications" The major features of the digital copying machine configured as described above include:
An image can be converted into an electric signal and read, and the electric signal can be restored by the image forming apparatus. Therefore, if various means for changing and transmitting the electric signal read at this time are provided, it can be applied to fields other than the copying machine. Therefore, by providing a scanner function, a file system function, and the like in addition to the FAX function and the printer function, these functions can be executed, and the application range is very wide. These extended functions are referred to as “applications” (hereinafter, also simply referred to as “apps”).

"Video signal" The electric signal of the image converted by the image reading device 200, the electric signal of the image inputted to the image forming apparatus 300, and the signal for synchronizing with the electric signal of the image are summarized. Here, it is expressed as "video signal".

"Control Signal", "Command" In order to exchange a video signal between the image reading apparatus 200, the image forming apparatus 300, and the application, it is necessary to transmit information between the apparatuses.
This means is referred to as "control signal" or "command" issuance.

"System", "System Control", "System Controller" In recent digital copiers, not only one application but also a plurality of applications are simultaneously registered. Such a digital copier sharing one resource is referred to as a “system”, and a controller for controlling the system is referred to as a “system control”.
Expressed as "system controller".

"Resource", "Resource" A unit of functional unit shared by a plurality of applications is expressed as "resource" or "resource". The above-described system controller performs system control on a resource-by-resource basis. The resources managed by the digital copier of this case are “image reading device”, “image forming device”, “operation unit”, “memory”, “peripheral device (DF = document feeder,
Sorter).

"Shading", "Shading data", "Shading correction" In order to define the white level, the output when a pure white document is read is held for one line in the main scanning direction. These are called waveforms and shading data. It changes depending on the ambient temperature of the lamp, the lighting time, and the cumulative use time. This shading data is regarded as the maximum value of the read output, and the read image signal is corrected using the shading data. By performing this correction, an appropriate image signal is obtained.

1.4 Sheet Through Shading Operation The sheet through shading operation executed in the present embodiment is performed according to the procedure shown in FIG. In FIG. 1, the shading plate 140 is provided downstream of the document (sheet) reading position 132 in the sheet conveyance direction, and the scanner carriage 205 is moved from the A position 211 to the B position 212.
Is read (step S301), the shading data is generated (step S3).
02).

Then, the scanner carriage 205 is stopped at the B position 212 (step S303), and the scanner carriage 205 is further moved from the B position 212 to the A position 21.
1 to end the process (steps S304, 305,
306).

The scanner carriage 205 is driven by the scanner drive motor 204 shown in FIG. The scanner carriage 205 has the above-described exposure lamp 2.
01, a mirror 202 for allowing light to enter the CCD 203 is provided. In such a sheet-through system, the reading position is different from the shading position.
05 needs to be moved.

1.5 Hardware Configuration of Image Forming Apparatus FIG. 4 is a block diagram showing a hardware configuration of the digital copying machine according to the present embodiment. The digital copying machine 1 mainly includes a copy application 21 having a CPU 21a for controlling the operation of the image forming apparatus 200 and a system controller 10. The system controller 10 includes a memory unit 5 having an image memory 501.
00, image forming apparatus 300, image reading apparatus 200,
The document feeder 100 controls the CPU 2, the ROM 3, the RAM 4, and the operation unit 5, and is connected to each other via the CPU 2. The copy application 21 communicates control signals with each other via the system controller 10 and the control signal line 7, and is connected to the operation unit 5 via the operation unit control bus 8. Further, image data of an image read by the image reading device 200 is input to the copy application 21, the memory unit 500, and the image forming device 300 via the image forming signal bus 9, and a process corresponding to each application is executed. .

1.6 Software Configuration of Image Forming Apparatus FIG. 5 shows a software configuration of the digital copying machine according to the present embodiment. In this configuration, the software configuration has three layers,
That is, the application layer 20, the system control layer 3
0 and the device control layer 40. The application layer 20 incorporates a copy application 21 and other applications 22, and the system control layer 30 includes an operation unit controller 31, a memory unit controller 32, an image forming apparatus controller 33 connected to the system controller 10, respectively. An image reading device controller 34 and a document feeding device controller 35 are incorporated. Each of the controllers 31 to 35 includes an operation unit 5, a memory unit 500, and an image forming apparatus 30.
0, a controller for operating the image reading device 200 and the document feeding device 100, respectively. An input / output control 41 is incorporated in the device control layer 40, and the input / output control 41 is connected to the controllers 31 to 35.

Therefore, in the case of the digital copying machine 1, various applications other than the copy application 21 can be mounted by configuring a multitask type system. The copy application 21 performs control related to image formation. In order to configure a multitask type system, it is necessary to treat functional units as resources and perform management for sharing one resource with a plurality of applications.
The system control layer 30 performs this management. In the system control layer 30, the system controller 10 is in charge of input and output of information of each controller 31 to 35 and each application.

The device control layer 40 includes the system control layer 3
Conversion from driving and inputting mechanical inputs and outputs of clutches, sensors, motors, and the like to actually move the apparatus is performed from logical instructions such as commands and control signals from 0.

As for the document feeder 100, there are a method of performing command control using serial communication to operate sheet feeding, and a method of controlling by controlling the CPU 2 of the system controller 10, but either method is available.
In the document feeder 100, there is a method of detecting the next document by using the document set sensor 193. For example, when the document set sensor 193 is turned on when the trailing edge of the document has passed the registration sensor 101,
It can be considered that there is a next manuscript. By doing so, it is possible to determine whether there is the next reading before the reading of the previous document is completed.

1.7 Flow of Image Data Related to Shading Correction The flow of image data relating to shading correction is shown in FIG. 6 together with a hardware configuration centering on image processing. In the figure, data 601 read by the CCD 203 is amplified, A / D converted by an A / D converter 602, and enters a shading correction circuit 603. After being corrected by shading data 605 obtained in advance by a shading operation and stored in a memory,
The image processing unit 604 performs image processing based on the correction data stored in the image correction memory 606, and
At 08 (300), an image is formed. The A / D converter 602, the shading correction circuit 603, the image processing unit 604, and the image forming unit 608 are controlled by a CPU 607 (same as the CPU 2 in FIG. 4).

The digital copying machine 1 is provided with a timer as a peripheral function (device) 609, and the counter is periodically counted up, and time can be measured based on the count. From that time, the lighting time of various lamps can be controlled. Here, if there is no next operation instruction for a certain period of time after the reading is completed, the exposure lamp 201 is turned off. Further, a load system 610 such as a motor or a clutch and a sensor 611 are connected to the CPU 607,
It is controlled by the CPU 607. Note that the peripheral function 607, the load system 610, the sensor 611, and the like are incorporated in the device control layer 40 in software.

1.8 Synchronization of Reading Original and Transfer Paper On the other hand, not only the digital copying machine 1 but also a copying machine needs to synchronize the reading original and the transfer paper, and the timing is as shown in FIG. The reading and writing operations are started only after the preparation of the original and the paper (transfer paper) from the start of copying (steps S701 to 704) (step S705).
In addition, in the case of FAX, there is a case where synchronization with a reading operation is necessary, such as preparation of FAX application and synchronization of reading.

1.9 Shading Operation Hereinafter, the shading operation in this embodiment will be described.

Here, an example will be described assuming that two originals are read. The control does not change even with a plurality of three or more sheets. In the following description, the shading operation means that the traveling body (scanner carriage) 205 moves from the reading position 132 to the reference white plate (shading plate) 14.
It refers to an operation of moving to the position 0, collecting shading data, and moving the traveling object 205 to the reading position 132. FIG. 8 shows the timing at which the shading operation is performed immediately after reading.

FIG. 8 is a timing chart showing the shading operation accompanying the drive 810 of the scanner motor, the fetching period 820 of the shading data, and the image effective area 83.
The timing of 0 is shown. Here, the timing of the start of reading the first image 803, the end of reading the first image 805, the start of reading the second document 808, the shading operations 801 and 806, and the shading data capture period 802 and 807 and the timings of the original reading periods 804 and 809 are shown.

This operation includes the following four cases.

1) For reading the first sheet, a shading operation is performed before reading, and a shading operation is also performed after reading is completed (immediately after obtaining necessary image data).

The first half of FIG. 9 is a flowchart showing a control procedure of the shading operation. In this process,
First, operation parameters necessary for the shading operation and the reading operation are set (step S901), and the shading operation is performed (step S902). After the shading operation, the reading operation is started (step S90).
3) Wait for completion of reading (step S904). After the reading is completed (step S905), a shading operation is performed (step S906).

With this processing, in the apparatus provided with the image reading apparatus 100 having a configuration that requires the shading operation accompanied by the movement of the scanner carriage 205, the first sheet is read before the reading operation. After the end of reading (immediately after acquiring necessary image data), the shading operation is performed. By doing so, the shading operation for reading the next document is performed before the next document comes to the reading position, thereby improving the throughput of continuous reading of a plurality of sheets.

2) Since the shading operation has already been performed on the second sheet when the first sheet has been read, no shading operation is performed before reading.

FIG. 9 is a flowchart showing the control procedure of the shading operation. When the shading operation is completed (Step S907) and the next reading preparation is completed (Step S908), the operation parameters are set (Step S909), the reading operation is started (Step S910), and the completion of the reading is waited (Step S91).
1). After the reading is completed (step S912), the shading operation is performed (step S913), and the process ends.

With this processing, when the shading operation is performed immediately after reading the first document,
Since the shading operation of the next original is not performed, the throughput of continuous reading of a plurality of sheets is improved.

3) After the shading operation after the completion of reading the first sheet, if there is enough time until the next reading is started due to preparation of transfer paper and the control to turn off the exposure lamp is performed, the operation is repeated again. The exposure lamp 201 must be turned on. In that case, the shading operation is performed again to obtain a high quality image.

FIG. 10 is a flowchart showing a control procedure of the shading operation. In this process, first,
Operation parameters necessary for the shading operation and the reading operation are set (step S1001), and the shading operation is performed (step S1002). After the shading operation, the reading operation is started (step S100).
3) Wait for completion of reading (step S1004). After the reading is completed (step S1005), a shading operation is performed (step S1006). This is the operation of the first sheet. When the shading operation is completed (step S1007) and the preparation for the next reading is completed (step S1007).
1008), operating parameters are set (step S1)
009). Up to this point, the control procedure is the same as in FIG.

Next, it is determined whether or not the exposure lamp 201 is off (step S1010). If the exposure lamp 201 is off, the lamp is turned on there (step S1011), and a shading operation is performed (step S1011).
1012). Thereafter, a reading operation is started (step S1013), and the second sheet is read. After the reading is completed (steps S1014 and S1015), the shading operation is performed (step S1016), and the process ends (step S1017).

That is, after the original is read, the shading operation is performed, and thereafter, when the exposure lamp 201 is turned off due to a waiting time in the synchronous operation, etc., the shading operation before the original reading is performed without omitting the exposure lamp 20.
By turning on 1 and performing the shading operation again before reading the original, appropriate shading data can be obtained.

4) After the shading operation after the completion of the reading of the first sheet, there may be a time lag before the start of the next reading due to synchronization preparation or the like. In such a case, the shading operation is performed again to obtain a high quality image.

FIG. 11 is a flowchart showing a control procedure of the shading operation. In this process, first,
Operation parameters necessary for the shading operation and the reading operation are set (step S1101), and the shading operation is performed (step S1102). After the shading operation, the reading operation is started (step S110).
3) Wait for completion of reading (step S1104). After the reading is completed (step S1105), a shading operation is performed (step S1106). This is the operation of the first sheet. When the shading operation is completed (step S1107) and preparation for the next reading is completed (step S1107).
1108), and set operation parameters (step S1).
109). Up to this point, the control procedure is the same as the control procedure of FIGS. 9 and 10 described above.

Next, it is determined whether or not a certain time has elapsed since the previous shading operation (step S).
1110) When it is determined that the predetermined time has elapsed, a shading operation is performed (step S111).
1). If the fixed time has not passed or step S
When the shading operation is completed in step 1111, the reading operation is started (step S 1012), and the second sheet is read. Wait for completion of reading (steps S1113, S1
114) Perform shading operation (step S111)
5), end the process (step S1116).

As described above, after the original is read, the shading operation is performed. Then, when the lighting time of the exposure lamp 201 is long due to the waiting time in the synchronous operation or the like, the shading operation is performed before the original is read. 201 becomes less susceptible to aging, and appropriate shading data can be obtained.

2. Second Embodiment In the first embodiment, when the user switches the image quality mode in the middle of a plurality of originals, or when the user switches the background removal mode, the shading data for the next original is read again. No special consideration was given. Therefore, in the second embodiment, shading data is re-acquired to form an image in response to these switchings.

In this embodiment, the "schematic configuration of image forming apparatus (digital copying machine)" to 1.1 described in the first embodiment with reference to FIGS. 1 to 7 described above. Since the respective configurations and operations up to "Synchronization of read original and transfer paper" are the same as those in No. 8, overlapping description will be omitted.

In the second embodiment, the "background removal mode" is a mode for removing background dirt or light-colored background of a paper sheet. When reading a document, a certain level below the read signal level is cut. It is done by doing. This makes it possible to remove black spots, dust, and thin background read by the scanner. The user can select, and on the operation unit, "automatic density",
There is a key with a name such as “background removal”. In the background removal processing, removal is performed by processing the acquired shading data. Processing and processing of shading data for background removal is now known.

The operation is switched by the user pressing a key, and the operation unit 5 shown in FIG.
"ON" and "OFF" are toggled.

In the "image quality mode", the digital copying machine has a mechanism for performing image processing (FIG. 6-604) and changing the image quality. Specifically, image processing such as error diffusion processing and dither processing is performed. Normally, the operation unit 5 includes “character”, “text photograph”, “photo”
There is a switching key with a name such as With this switching key, the setting of the background removal function is also automatically switched. For example, "Text" and "Text Photo" have background removal ON. "Picture" is background removal OFF. In the photo mode, since gradation is emphasized, background removal is not usually performed. However, this setting is variable and is not limited.

The mode is changed by pressing the key by the user, the pressing is notified from the operation unit 5, and the mode changes each time the user presses "character" → "character photograph" → "photo" → "character". .

Hereinafter, the shading operation in this embodiment will be described.

Here, an example will be described assuming an operation from the first sheet when reading a plurality of originals. As described above, the shading operation means that the traveling body (scanner carriage) 205 moves from the reading position to the reference white plate (shading plate) 140, collects shading data, and further moves the traveling body 205 to the reading position. Refers to the action to be performed.

FIG. 12 is a timing chart showing the timing of performing shading immediately after reading. FIG.
The timing chart 2 shows the driving of the scanner motor 12.
10 shows the timing of a shading operation, a shading data capture period 1220, and an image effective range 1230 accompanying the shading operation 10. Here, the reading of the first image is started 1231, the reading of the first image is completed 123
The timings of starting reading 1234 of the third and second documents and shading operations 1211, 1212, 121
3. Shading data capture period 1221, 1
222, 1223 and original reading period 123
2,1235 timings are shown.

As can be seen from the timing chart, the shading 121 is executed 1233 immediately after reading the first sheet.
Perform 2,1222. When the switching between the image quality mode and the background removal mode is found, the shading operations 1213 and 1223 are performed again after the shading operations 1212 and 1222 immediately after reading. This timing is different from the timing shown in FIG. 8 in that the switching between the image quality mode and the background mode occurs immediately after the first sheet has been read, and the shading operations 1213 and 1223 are performed before the second sheet is read. Is inserted.

That is, if the switching between the image quality mode and the background removal mode is switched during reading, the read original cannot be changed, but the image quality mode and the background removal mode are reflected from the next original. Is done. Therefore, at the start of reading the next document, it is determined whether or not the image quality mode and the background removal mode are different from those at the time of the previous reading, and if the modes are different (the switching between the image quality mode and the background removal mode occurs). Perform shading operation. Therefore, in order to improve productivity, such as this time, in the case where the shading operation is performed immediately after the end of the reading operation, if the image quality mode and the background removal mode are changed, the shading operation is performed again before the next reading operation starts. It is necessary to perform a shading operation. In the following description, “image quality mode switching occurrence” and “background removal mode switching occurrence” indicate that a setting different from the mode at the time of the previous reading start is performed.

This operation will be described with reference to the flowcharts of FIGS.

FIG. 13 shows that the shading operation is performed before reading the first sheet, and the shading operation is also performed after the reading is completed (immediately after obtaining necessary image data). 9 is a flowchart illustrating a processing procedure when the error occurs.
In this process, first, operation parameters necessary for the shading operation and the reading operation are set (step S1).
301), and perform a shading operation (step S13).
02). After the shading operation, the reading operation is started (step S1303), and the reading operation is waited for (step S1304). After reading is completed (step S130)
5) Perform shading (step S1306).
The shading operation ends (step S1307),
If the next document is ready to be read (step S13)
08), the operation parameters of the next document are set (step S1309), and it is determined whether or not image quality mode switching has occurred (step S1310). Then, when the switching of the image quality mode occurs, the shading operation is performed (step S1311). After the shading operation is completed, a reading operation is started (step S1312),
After the reading is completed (step S1314), the shading operation is performed (step S1315). If there is a next original, the operation from step S1307 is repeated.

FIG. 14 shows that the shading operation is performed before reading the first sheet, the shading operation is also performed after the reading is completed (immediately after obtaining necessary image data), and then the background removal mode is switched. 9 is a flowchart illustrating a processing procedure when the error occurs. This process is a process of determining whether or not the switching of the background removal mode has occurred (step S1310 '), instead of the process of determining whether or not the image quality mode switching of step S1310 in FIG. 13 has occurred. Since the processing procedure is the same as each processing in FIG. 13, the duplicate description will be omitted.

When the shading operation is performed immediately after reading in consideration of productivity, an appropriate shading operation is performed even if the image quality mode is switched, so that a high-quality image reading that meets the needs of the user can be performed. . Further, since it is determined whether there is a change in the image quality mode immediately before the start of reading or whether there is a change in the background removal mode, it is possible to read an image that meets the user's needs until just before reading. Further, since the shading operation has already been performed at the end of the reading, the reading can be performed without performing the shading operation even when the image quality mode switching does not occur or when the background removal mode switching does not occur.

[0090]

As described above, according to the first aspect of the present invention, the shading operation is performed by moving the traveling body to the position of the shading plate before and after reading the original, so that the next original can be read. , The shading operation for reading the next document is completed, whereby the throughput of continuous reading of a plurality of sheets can be improved.

According to the second aspect of the present invention, when the shading operation is performed by moving the traveling body after the completion of the reading of the previous document, the shading operation before reading the next document is omitted and the document is read. Since the shading operation is performed immediately after the end of reading, the same operation is not performed continuously, so that the throughput of continuous reading of a plurality of sheets can be improved.

According to the third aspect of the present invention, when the exposure lamp is turned off before reading the next original, the traveling body is moved to the position of the shading plate before the next original is read. To perform the shading operation, so even if the exposure lamp is turned off,
It is possible to obtain appropriate shading data,
As a result, accurate image data can be obtained.

According to the fourth aspect of the present invention, in the second aspect of the present invention, when a predetermined time has elapsed until the next original reading operation, the traveling body is moved to the shading plate before reading the next original. Since it is moved to the position to perform the shading operation, it is possible to obtain appropriate shading data even when the exposure lamp is turned on for a long time due to the waiting time in the synchronous operation, etc. Can be

According to the fifth aspect of the present invention, when the mode of the image quality of the previous document is changed by the time the reading of the next document is started, the reading of the next document is performed before the reading of the next document. Since the image quality is set and the shading operation is performed, high-quality image reading that meets the needs of the user can be performed. Further, since it is determined whether or not the image quality mode has changed just before the start of reading the next document, it is possible to read an image that meets the needs of the user until immediately before reading. Further, since the shading operation has already been performed at the end of the reading, even if the image quality mode switching does not occur, the reading can be performed without performing the shading operation.

According to the sixth aspect of the present invention, when a plurality of originals are used, if the background removal setting of the previous original is switched by the start of reading of the next original, the reading before the next original is read. Since the shading operation is performed after the background removal setting is performed, the same effect as that of claim 5 can be obtained.

According to a seventh aspect of the present invention, there is provided an image processing means for performing predetermined signal processing based on image data input from the image reading apparatus according to any one of the first to sixth aspects, and Since there is provided an image forming means for forming a visualized image based on the image signal processed by the image processing means, it is possible to obtain accurate image data without performing unnecessary shading operation, thereby improving quality. Can be output.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a document feeder provided in a digital copying machine according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of a digital copying machine according to an embodiment of the present invention.

FIG. 3 is a flowchart showing an operation procedure of a sheet through shading operation according to the embodiment of the present invention.

FIG. 4 is a block diagram illustrating a hardware configuration of a digital copier main body according to the embodiment of the present invention.

FIG. 5 is a block diagram showing a system software configuration of the digital copying machine according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a hardware configuration focusing on image processing and a flow of image data of the digital copying machine according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a processing procedure for setting timing for synchronizing a read original and a transfer sheet.

FIG. 8 is a timing chart showing a shading operation associated with driving of a scanner motor, a period of capturing shading data, and a timing of an image effective range according to the first embodiment of the present invention.

FIG. 9 is a flowchart illustrating a control procedure of a shading operation according to the first embodiment of the present invention.

FIG. 10 is a flowchart illustrating a control procedure when an exposure lamp is off in a shading operation according to the first embodiment of the present invention.

FIG. 11 is a flowchart illustrating a control procedure of a shading operation when a predetermined time has elapsed from a previous shading operation according to the first embodiment of the present invention.

FIG. 12 is a timing chart showing a shading operation associated with driving of a scanner motor, a shading data capture period, and a timing of an image effective range when image quality mode switching / background removal mode switching occurs in the second embodiment of the present invention. It is.

FIG. 13 is a flowchart illustrating a control procedure of a shading operation when an image quality mode switch occurs according to the second embodiment of the present invention.

FIG. 14 is a flowchart illustrating a control procedure of a shading operation when a background removal mode is switched according to the second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 digital copying machine 2,607 CPU 10 system controller 20 application layer 21 copy application 30 system control layer 40 device control layer 100 document supply device (document feeding device) 132 document reading position 140 shading plate (reference white plate) 200 image reading device 201 Exposure lamp 202 Mirror 203 CCD 204 Scanner drive motor 205 Carriage (scanner carriage) 300 Image forming device 400 Paper feed device 500 Memory unit 603 Shading correction circuit 604 Image processing unit 605 Shading data storage memory 606 Image correction memory

Claims (7)

[Claims] An exposure optical system for reading a document conveyed at a constant speed on a platen; a shading plate for correcting a white reference of the read image information; and an exposure optical system for reading the shading plate. An image reading apparatus comprising: a traveling body that moves a reading position of the optical system; and a control unit that moves the traveling body to a position of the shading plate to perform a shading operation before and after reading a document. 2. An exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a reference of white of read image information, and an exposure optical system for reading the shading plate. A moving body that moves the reading position of the optical system, and if the shading operation is performed by moving the running body after reading of the previous document, the shading operation before reading the next document is not performed. And a control unit for causing a shading operation to be performed immediately after the reading is completed. 3. When the exposure lamp is turned off before reading the next document, the control means moves the traveling body to the position of the shading plate and performs a shading operation before reading the next document. 3. The image reading device according to claim 2, wherein: 4. When a predetermined time elapses before a next document reading operation, the control means moves the traveling body to a position of the shading plate before reading a next document to perform a shading operation. 3. The image reading device according to claim 2, wherein the reading is performed. 5. An exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a white reference of read image information, and an exposure optical system for reading the shading plate. A traveling body for moving the reading position of the optical system, and a control means for moving the traveling body to a position of the shading plate to perform a shading operation before reading a document, the control means comprising: If the mode of the image quality of the previous document is changed by the time the next document is read, the shading operation must be performed by setting the image quality before reading the next document. Characteristic image reading device. 6. An exposure optical system for reading a document conveyed at a constant speed on a platen, a shading plate for correcting a white reference of the read image information, and an exposure optical system for reading the shading plate. A traveling body for moving the reading position of the optical system, and a control means for moving the traveling body to a position of the shading plate to perform a shading operation before reading a document, the control means comprising: If the background removal setting of the previous document is changed by the start of reading the next document when multiple documents are scanned, the background removal setting must be performed before the next document is read and the shading operation is performed. An image reading device characterized by the above-mentioned. 7. An image processing means for performing predetermined signal processing based on image data input from the image reading device according to claim 1, and processing performed by the image processing means. An image forming apparatus comprising: an image forming unit that forms a visual image based on an image signal.