JP4334328B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus, and more particularly to a reading technique for detecting a stain on a contact glass and avoiding a useless image reading operation.

In general, in an image reading apparatus, a book read type in which an exposure scanning unit scans an original placed on a contact glass and an exposure scanning unit of a scanner unit are moved, and the original is moved and read. There is a so-called sheet-through type. Of these, in particular, in sheet-through type reading, the sheet-through contact glass may become dirty due to the document coming into contact with the sheet-through contact glass. Due to this dirt, a “streaks” in the reading direction appears in the read image in a dusty part.
To mitigate this, after the image reference correction process called shading processing, the dirt reference plate on the top surface of the sheet-through contact glass is read for several lines, and the dirt level is detected by comparing the reference level with the dirt level. To do. As a result, processing is generally performed such as stopping reading and prompting the user to clean the contact glass for sheet through, or performing image correction on a portion where dust is detected.
For example, in Japanese Patent Laid-Open No. 2001-257877, a reference white board is read to detect shading on the contact glass based on the read data while performing shading correction, and when dirt is detected, It is disclosed that the reading of a document cannot be performed or that the user is encouraged to clean.
JP 2001-257877 A

However, in continuous reading by the above-described sheet-through reading, how to improve productivity is one problem, but there is a problem that productivity is lowered because reading is interrupted due to dirt detection and the detection result. is there.
In general, in sheet-through type continuous reading, in order to increase productivity, the next original is fed simultaneously with the discharge of the original currently being read. If the cancellation is performed, there is a problem that it is necessary to return the original to read it again, or that the possibility of damaging the original is increased by repeatedly feeding paper.
In the conventional example disclosed in Patent Document 1, shading correction and dirt detection are performed with one white reference plate. Generally, in an image reading apparatus having two reading methods of book read type reading and sheet through reading, a reference plate used in book read type reading is used in order to make the image correction level the same. A reading operation is required, but this is not taken into account.
In view of such a problem, the present invention detects stains and performs appropriate processing based on the result in an image reading apparatus capable of reading two types, in particular a book lead type and a sheet through type, and efficiently reads. An object of the present invention is to provide an image reading apparatus having a control method and a user interface for performing the above.

For the present invention to solve the above problems, according to claim 1, the book lead type for reading the image information of the document placed on the contact glass by exposure scanning unit is moved in the sub-scanning direction, the exposure scanning An image reading apparatus provided with a sheet-through type that reads image information of an original by moving the original in the sub-scanning direction without moving, and for detecting adhering matter adhering to the contact glass as dust And a white reference portion that is a white reference of a document for shading correction. After the white reference portion is read by the exposure scanning unit and the shading correction operation is performed, a plurality of Before reading the first sheet of the original bundle, the dust detection reference portion is read by the exposure scanning unit through the contact glass. When the adhering matter is detected, the feeding and reading of the original are stopped, and when the adhering matter is not detected, the feeding and reading of the original are executed, and the second and subsequent sheets of the original bundle are Even when an adhering matter is detected by reading the dust detection reference portion by an exposure scanning unit, the user should continue to feed and read the original and remove the adhering matter regardless of the detection level. It features an image reading device that warns.
Depending on the document to be scanned, etc., if the stain is not detected before scanning the first sheet of a regular document bundle, the state of stain on the sheet-through contact glass will not change significantly in the next scan. Absent. Therefore, when reading documents continuously, stop processing is performed according to the result of stain detection performed before the first page is read, and only warning is given for stain detection before reading the second and subsequent pages, and no stop processing is performed. By doing so, it is possible to reduce the possibility of an abnormal image even when the reading is not stopped halfway when continuously reading the document.
According to this invention, when the stain is detected by the stain detection before reading the first sheet of the document bundle, the paper feeding and reading operation is stopped, and the dust is detected by the detection before reading the second sheet transition. In such a case, only the warning is performed without stopping the reading, and the reading is continued, so that the reading operation can be efficiently performed while reducing the abnormality of the image.

As described above, according to the present invention, when the stain is detected by the stain detection before reading the first sheet of the document bundle, the feeding and reading operations are stopped, and the detection before reading the second sheet transfer is detected. If dust is detected in the system, scanning is not interrupted, only warning is given, and scanning is continued, so that scanning can be performed efficiently while reducing image abnormalities. The

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a diagram showing a system configuration example of the present invention. The system 100 receives an application request 30 for issuing an operation request, issues an operation request to each device in response to the request, a controller layer 31 for managing each device, and receives a request from the controller layer 31 in actuality. It is comprised from the device layer 32 which performs this operation | movement. The controller layer 31 includes an image recording control unit 31a that controls an image storage device such as a memory for storing images and a hard disk. The device layer 32 includes an image reading device 34 and an image output device 33. It has become. For example, when a reading start button on the operation unit is pressed, an image reading request is sent from the application layer 30 to the controller layer 31. In response to this, the controller layer 31 instructs the image reading device 34 to prepare for reading such as computation and register set for performing the requested reading operation, and simultaneously stores the read image data. A request is sent to the image recording control unit 31a so as to prepare the memory, hard disk, and the like. On the other hand, the image reading device 34 and the recording device respectively notify the controller layer 31 that preparation has been completed when reading is ready. The controller layer 31 issues a reading start request to the image reading device 34 upon completion of preparation of both. The image reading device 34 receives it and performs actual reading, and transfers the read data to the recording device. After the transfer is completed, the controller layer 31 issues an output request to the image output device 33 as necessary. When receiving an output request from the controller layer 31, the image output device 33 outputs the image data stored in the recording device to each medium. In the figure, thin arrows represent the flow of requests and commands, and thick arrows represent the flow of image data.
FIG. 2 is a schematic view of the entire image reading apparatus according to the embodiment of the present invention. The image reading apparatus 150 includes an automatic document feeder (hereinafter referred to as ADF) 20 that automatically conveys a bundle of documents at an upper portion thereof. The ADF 20 includes a document table 21 on which a bundle of documents is placed and a document 1 A sheet feeding roller 22 that separates the sheets one by one and feeds them to the guide roller 23, a guide roller 23 that transports the fed document to the reading position, and a sheet ejection roller 24 that ejects the document that has been read to the document collecting stand. And a document collection table 25 for storing the discharged document. Further, in the lower part, a sheet-through contact glass 1 that allows a moving document to pass through in order to read the sheet-through document, a book-read contact glass 2 on which a book document is placed, and shading correction of the document are performed. A white reference plate 3 serving as a white reference level, a dust detection reference plate 6 serving as a dirt reference level, a traveling body 5 that scans image data of a document in the sub-scanning direction, and a document configured on the traveling body 5 Are provided, a plurality of mirrors 8 that reflect the reflected image, and a CCD 9 that photoelectrically converts the reflected image.
FIG. 3 is an enlarged view of the vicinity of the white reference plate 3 of FIG. The same reference numerals are assigned to the same components, and duplicate descriptions are omitted.

The operation of the image reading apparatus 150 will be described with reference to FIGS. The traveling body 5 is fixed at the sheet-through reading position P1, and the document placed on the document table 21 is allowed to pass through the sheet-through mode, and the traveling body 5 is moved under the stationary document on the contact glass 2 at a constant speed. It is possible to read in the book read mode in which the original is read by moving it.
In the book read mode, shading correction is performed by reading the white reference plate 3 when the traveling body 5 reaches the white reference plate reading position P2 while moving under the book reading contact glass 2. In the sheet-through mode, the shading correction is performed by moving the traveling body 5 to the lower P2 of the white reference plate 3 and reading the white reference plate 3 before passing the document to the reading position. Thereafter, the traveling body 5 is moved under the contact glass 1 and then returned to the sheet-through reading position P1 (hereinafter, a series of operations of the traveling body 5 is referred to as a DF shading operation). Thereafter, the document is read by passing it over the sheet-through contact glass 1. Normally, by performing shading correction using the same white reference plate 3 in the book read mode and the sheet through mode as described above, there is no difference in image quality regardless of whether reading is performed in the book read mode or the sheet through mode. It has become.
Further, when reading in the sheet-through mode, if a request for reading the next original is issued during reading, a DF shading operation for the next reading is performed immediately after the reading of the original is completed. . When reading a plurality of documents on the document table 21 continuously, when reading the second and subsequent documents, a DF is performed immediately after the reading of the immediately preceding document when a read start request is received from the controller. Shading correction is performed using correction data obtained by the shading operation.
Further, after completion of the DF shading operation, the dirt detection reference plate 6 is read. Since dust and dirt adhere to the sheet-through contact glass 1, dust and dirt on the sheet-through contact glass 1 can be detected. Regarding the movement of the document in the sheet-through mode, the document is first moved to the front of the reading position by the sheet feeding roller 22 (hereinafter referred to as a sheet feeding operation) in order to select the size of the transfer sheet. Then, movement for reading is performed at a timing at which reading is possible (hereinafter referred to as sheet-through operation). After the sheet-through operation, the document is discharged to the document collection table 25.
In the case of sheet-through reading, in order to increase the reading efficiency, when the magnification of the read original does not change, the next paper feeding operation can be performed while the previous original is being discharged. It is common.

FIG. 4 is an operation timing chart at the time of reading the first document in sheet-through reading according to the present invention. From the top of the figure, the scanner motor drive, the stain detection, the first DF original passing sheet, the second DF original passing sheet, the image effective range are shown, and are indicated as low level active. In this operation, when a read preparation request is issued from the controller, the image reading device turns on the lamp, sets the parameters of each operation unit, etc., and when finished, issues a memory request to the controller and stores the read image. Is requested to the controller to notify the completion of reading preparation. In response to this, when a reading start request is made from the controller, the image forming apparatus starts the DF shading operation and the scanner motor is driven. When the controller prepares the memory necessary for reading, the controller issues a memory permission notice to the image reading apparatus.
When the DF shading operation is completed and the traveling body reaches the reading position P1, reading for dirt detection is performed. If dust is detected in the sheet-through contact glass 1 at this time, the controller notifies the controller that there is dust and ends the reading operation. Upon receiving this notification, the controller warns the user and prompts for cleaning. If no dust is detected, the document feeding operation and the sheet through operation are continuously performed. However, the next document is not fed at the same time.
FIG. 5 is an operation timing chart during continuous reading in sheet-through reading according to the present invention. In order from the top of the figure, the scanner motor drive, the stain detection, the Nth sheet of DF manuscript passing, the N + 1th sheet of DF manuscript passing, and the image effective range are represented as low level active. When the original is continuously read, a read preparation request for the next original is issued from the controller to the image reading apparatus during the original reading. Accordingly, a memory request is issued from the image reading apparatus to the controller, the controller secures the memory, and issues a memory permission notice to the image reading apparatus. The image reading apparatus performs DF shading operation and dirt detection immediately after the last reading is completed. When the stain detection and the memory permission notification from the controller are completed, the next document feeding operation and sheet through operation are performed to read the image. In this way, even if dirt detection is performed and the reading is stopped when dust is detected, the reading can be resumed without replacing the original.
In the above embodiment, even when dust is detected, reading can be prevented from stopping if the detection level is low. In this way, even if dirt detection is performed and the reading is stopped when dust is detected, the reading can be resumed without replacing the original.

FIG. 6 is a timing chart showing the operation when only the warning is given and the reading operation is not stopped even when dust is detected by performing the dirt detection (when the first original is read). From the top of the figure, the scanner motor drive, the stain detection, the first DF original passing sheet, the second DF original passing sheet, the image effective range are shown, and are indicated as low level active. In this case, the reading preparation request is issued from the controller, the lighting of the lamp, performs such settings of the parameters of each operating unit issues a memory request to the controller when finished, securing of a memory to store the read image Is notified to the controller. In response to this, a read start request is made from the controller. When the preparation of the memory necessary for reading is completed, the controller issues a memory permission notice to the image reading apparatus to make a reading start request, and the image forming apparatus starts a DF shading operation.
In this case, since reading is not stopped, paper feeding is started simultaneously with DF shading.
Here, assuming that the time required for the DF shading operation is Ts, the time required for the dirt detection is Tl, and the time from the start of the sheet through operation to the actual reading position is Td, the time from the start of the DF shading operation to the time T When the time T = Ts + Tl−Td has elapsed, the sheet-through operation is performed.
FIG. 7 is a timing chart showing the operation when only the warning is given and the reading operation is not stopped even when dust is detected by performing the dirt detection (during continuous reading). In order from the top of the figure, the scanner motor drive, the stain detection, the Nth sheet of DF manuscript passing, the N + 1th sheet of DF manuscript passing, and the image effective range are represented as low level active. When there is a next original and reading is performed continuously, the next original is fed simultaneously with the discharge of the previous original. Further, when the image reading is completed, the DF shading operation and the smear detection are started, and when the memory permission notification is received from the controller, the next original is written when T = Ts + Tl−Td has elapsed from the start of the DF shading operation. Start the sheet-through operation.
By operating each unit in this way, only a warning is given when dust is detected, and if the reading operation is not stopped, if the time required for the paper feeding operation is Tk, reading is performed after the stain detection is completed. Rather than starting, the time between readings can be shortened by Tk + Td, and the reading operation can be performed efficiently.

FIG. 8 is an operation timing chart when the first original is read. From the top of the figure, the scanner motor drive, the stain detection, the first DF original passing sheet, the second DF original passing sheet, the image effective range are shown, and are indicated as low level active. If dirt is detected by the dirt detection before reading the first sheet of the original bundle, the feeding and reading operation is stopped, and if dust is detected by the detection before reading the second sheet, Reading is not interrupted but only warning is given and reading is continued.
Depending on the document to be scanned, etc., if dust is not detected before scanning the first sheet of a regular document bundle, the state of the dust on the contact glass for sheet-through will not change significantly in the next scanning. Absent. Therefore, when reading documents continuously, stop processing is performed according to the result of stain detection performed before the first page is read, and only warning is given for stain detection before reading the second and subsequent pages, and no stop processing is performed. By doing so, it is possible to reduce the possibility of an abnormal image even when the reading is not stopped halfway when continuously reading the document.
As another embodiment, a user can individually set a detection level for stopping reading of a document and a detection level for performing only a warning. Depending on the user who handles the image reading apparatus, the required read image differs. There are users who want to reduce the troubles such as cleaning even if there is some dirt on the image, and users who place importance on the quality of the image even if it takes some trouble. Therefore, by allowing each user to freely change the level of dirt that stops scanning when dirt is detected and the level of dirt that generates a warning, image reading and dirt detection that meet the needs of individual users are performed. be able to.
As another embodiment, the user can set which of the above-described controls is used for reading. Each of the reading methods shown above has advantages and disadvantages. Therefore, by making it possible to select each reading method, each user can obtain the image level and the productivity of image reading according to their needs.

The figure which shows the system structural example of this invention. 1 is a schematic view of an entire image reading apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged view of the vicinity of a white reference plate 3 in FIG. 2 according to the present invention. 6 is an operation timing chart at the time of reading the first document in sheet-through reading according to the present invention. The operation | movement timing chart at the time of the continuous reading in the sheet through reading of this invention. 9 is a timing chart showing an operation when only a warning is issued and the reading operation is not stopped even when dust is detected by performing the dirt detection of the present invention. 9 is a timing chart showing an operation when only a warning is issued and the reading operation is not stopped even when dust is detected by performing the dirt detection of the present invention. 6 is an operation timing chart when the first original of the present invention is read.

Explanation of symbols

  1 contact glass for sheet through, 2 contact glass for book lead, 3 white reference plate, 5 traveling body, 6 dust detection reference plate, 7 lamp, 8 mirror, 9 CCD, 20 automatic document feeder, 21 document table, 22 feed Paper roller, 23 guide roller, 24 paper discharge roller, 25 document collection table, 150 image reading device

Claims (1)

A book lead type that reads image information of a document placed on a contact glass by moving the exposure scanning unit in the sub-scanning direction, and the exposure scanning unit moves the document in the sub-scanning direction without moving the exposure scanning unit. An image reading apparatus having a sheet-through type for reading image information of an original,
  A dust detection reference portion serving as a reference for detecting the adhered matter adhering to the contact glass as dust, and a white reference portion serving as a white reference of the document for shading correction,
  After the white reference portion is read by the exposure scanning unit and the shading correction operation is performed, the dust detection reference portion is moved through the contact glass by the exposure scanning unit before reading the first sheet of a plurality of document bundles. When the adhering matter is detected by reading, the feeding and reading of the original are stopped. When the adhering matter is not detected, the feeding and reading of the original are executed, and the second and subsequent sheets of the original bundle are executed. Even if the dust detection reference portion is read by the exposure scanning unit and the adhering matter is detected, the adhering matter should be removed to the user by continuously feeding and reading the original regardless of the detection level. An image reading apparatus that warns the effect.

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