JP2005197895A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an image reading apparatus to have a rotatable white rod in an image reading unit, and perform dust detection such as paper pieces adhered on the glass of the reading unit by utilizing a space between originals. <P>SOLUTION: To avoid the lowering of productivity in original reading in a sheet-through ADF, the dust detection of the dust including paper pieces adhered on a contact glass 51 of the reading unit is performed by using the space between originals, in the image reading apparatus having the rotatable white rod 50 in the image reading unit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus using a sheet-through ADF, such as a scanner, a copying machine, a facsimile machine, and a multifunction machine.

When a document is read by the sheet through ADF, black streaks are generated due to a piece of paper or the like. However, when dust detection is performed, it is known that the reading unit needs to read a reference white plate (for example, Patent Document 1). To 3).
Japanese Patent Laid-Open No. 2001-157046 JP 2002-281251 A Japanese Patent No. 3159470

Therefore, although dust detection is performed, it is necessary to prevent the productivity of scanners, copiers, and the like from being affected by continuous reading of a document by sheet-through ADF. In addition, in order to detect dust by continuous image reading by sheet through, it is necessary to read several lines of the target object serving as a reference white plate at various locations.
Further, when a white bar is used, it becomes difficult to detect dust if the white bar is dirty. Therefore, it is necessary to detect whether the white bar is dirty. Since the user does not notice even if the white bar is dirty, it is necessary to notify the user as a warning and prompt cleaning.
In view of the above situation, an object of the present invention is to have a rotatable white bar in the image reading unit and detect dust such as a piece of paper adhering to the glass of the reading unit using the space between the originals. An object of the present invention is to provide an image reading apparatus.

In order to solve the above-mentioned problem, the invention according to claim 1 is an image reading apparatus in a sheet-through ADF, in which an image reading unit has a rotatable white bar, and a piece of paper attached to the contact glass of the reading unit. An image reading apparatus that detects dust including a gap between sheets of a document is characterized.
According to a second aspect of the present invention, the image reading apparatus according to the first aspect is characterized in that dust detection is performed by a white bar that rotates at a constant speed.
According to a third aspect of the present invention, there is provided the image reading device according to the second aspect, wherein the white level of the white reference white plate and the white bar is read to detect a stain on the white bar.
According to a fourth aspect of the present invention, there is provided the image reading device according to the third aspect, wherein when the stain on the white bar is detected, the user is notified that the glass portion of the white bar is dirty.

According to the present invention, dust on the reading unit glass is detected by reading the white bar at the top of the reading unit between the sheets of the document, so that dust detection can be performed without reducing productivity.
In the case of sheet-through ADF document reading, reading productivity is important, but productivity cannot be reduced in order to detect black streaks generated by a piece of paper or the like. Further, by reading the white bar that rotates constantly, the number of lines necessary for dust detection can be read from the white bar without moving the carriage.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of an embodiment of an image reading apparatus according to the present invention. First, the configuration operation of the present invention will be described.
A manuscript (not shown) placed on the platen glass 1 is irradiated by an illumination lamp 3 configured integrally with the first mirror 2, and the reflected light is a second mirror configured integrally with the first mirror 2. Scanning is performed by the mirror 4 and the third mirror 5.
Thereafter, the reflected light is converged by the lens 31 and irradiated to the CCD 6 for photoelectric conversion. The first mirror 2, the illumination lamp 3, the second mirror 4, and the third mirror 5 are movable in the A direction using the traveling body motor 7 as a drive source.
The documents stacked on the document tray 8 are sent to the transport roller pair 13 and the discharge roller pair 14 through the reading position B by the pickup roller 9, the registration roller pair 10, the transport drum 11, and the transport roller 12, and are discharged to the discharge tray. 32 is discharged.
When the document passes through the reading position B, the original is irradiated by the illumination lamp 3 that has been moved to the vicinity of the reading position B, and the reflected light is reflected by the first mirror 2 and the second mirror 4 and the third mirror that are integrally formed. Scanned by the mirror 5. Thereafter, the reflected light is converged by the lens 31 and irradiated to the CCD 6 for photoelectric conversion.
The pickup roller 9 and the registration roller pair 10 are driven by a paper feed motor (not shown), and the transport drum 11, the transport roller 12, the transport roller pair 13, and the paper discharge roller pair 14 are driven by a transport motor (not shown). Driven.
A contact image sensor 15 is installed at the reading position C. The contact image sensor 15 includes an LED (not shown) as a light source, a lens (not shown), and a sensor element (not shown). When the document passes through the reading position C, the opposite surface (back surface) read at the reading position B is irradiated by a lamp in the contact image sensor 15 installed at the reading position C.
The reflected light is converged by the lens on the contact image sensor 15, and the sensor element on the contact image sensor 15 is irradiated and photoelectrically converted. A white roller 17 is installed at a portion of the contact image sensor 15 facing the document, and can be used as a white member for shading correction at the time of reading by the contact image sensor 15.
An endor unit 18 and an endor platen 19 are installed between the transport roller pair 13 and the paper discharge roller pair 14. The endorser unit 18 is composed of a printing section made up of alphabet letters and numbers soaked with ink, and a pressure solenoid (not shown) that pressurizes the printing section in the endorser platen direction.
The original is stopped on the endorser unit 18, fixed in the pressurizing direction by the endorser platen 19, and alphabetic characters and numbers can be printed on the original surface by pressurizing the printing portion of the endorser unit 18.

FIG. 2 is an overall block diagram showing an image reading apparatus according to the present invention. In FIG. 2, the reflected light of the original that has entered the CCD 6 on the SBU 20 is converted into an analog signal having a voltage value corresponding to the light intensity in the CCD 6. The analog signal is divided into odd bits and even bits and output.
From the analog image signal, an analog processing circuit (not shown) dark potential portion is removed on the SBU 20, the odd bits and the even bits are combined, and the gain is adjusted to a predetermined amplitude, and then input to the A / D converter to be digital. Signaled.
The digitized image signal is subjected to shading correction, gamma correction, MTF correction, etc. by the NIPU 33 on the SCU 21 and then binarized, and is output as a video signal together with the page synchronization signal, line synchronization signal, and image clock. The
The video signal output from the NIPU 33 is output to the option IPU 26 via the connector 34. The video signal output to the option IPU 26 undergoes predetermined image processing in the option IPU 26 and is input to the SCU 21 again.
The video signal input to the SCU 21 again is input to a selector (not shown). The other input of the selector is a video signal output from the NIPU 33, and the option IPU 26 can select whether or not to perform image processing.
The video signal output from the selector is input to the SiBC 35 that manages image data storage means (DRAM), and is stored in an image memory constituted by the DRAM. The image data stored in the image memory is sent to the SCSI controller 36 and transferred to an external device such as a personal computer.
An expansion slot (not shown) is prepared on the SCU 21, and image data controlled by the SiBC 35 is transferred to an extension interface unit connected via the extension slot (not shown), and is transmitted by a predetermined interface means. Uses a configuration that can be transferred to an external device.

In FIG. 2, as an example, the network controller 27 is cited as a unit connected to an expansion slot (not shown). According to the configuration of FIG. 2, the image reading apparatus is connected via the network controller 27 in a network environment. Can be used.
At this time, the network operation panel 29 can be connected to the main image reading apparatus so as to be compatible with the network, and the main image reading apparatus can be operated from the network operation panel 29.
The analog image signal photoelectrically converted by the contact image sensor 15 is digitally converted on the RSBU 16. The digitized image signal is sent to the RCU 23 after shading correction is performed on the RSBU 16.
The RCU 23 is composed of an image memory composed of DRAM and SiBC that controls the image data memory. The RCU 23 once stores the image data in the image memory and then transfers the image data to the SCU 21. The image data sent from the RCU 23 to the SCU 21 and the image data output from the SiBC 35 on the SCU 21 can be switched, and one of the image data is selected and transferred to the SCSI controller 36.
A CPU 37, a ROM 38, and a RAM 39 are mounted on the SCU 21, and the CPU 37 controls the SCSI controller 36 to communicate with an external device such as a personal computer. The CPU 37 also performs timing control of the traveling body motor 7, which is a stepping motor, a paper feed motor, and a transport motor.
The ADU 30 has a function of relaying the power supply of electrical components used in the automatic document feeder (ADF) unit. An input port connected to the CPU 37 on the SCU 21 is connected to the main body operation panel 28 via the IOB 24.
A start switch (not shown) and an abort switch (not shown) are mounted on the main body operation panel 28. When each switch is pressed, the CPU 37 detects that the switch is turned on via the input port.
Further, an LED (not shown) is prepared on the main body operation panel 28, and displays the status of the image reading apparatus, for example, image data transfer or main body error occurrence.

FIG. 3 is a schematic diagram for explaining document reading according to the present invention. As shown in FIG. 3, the document glass 52 is transported by the transport rollers 55 and 56 as shown in FIG. 3, with the contact glass 51, the reference white 54, the white roller (white bar) 50, and the sheet-through reading position 53. Can be read.
The document 52 is transported by the transport rollers 55 and 56 while the rotatable white roller 50 is rotating at a constant speed.
FIG. 4 is a flowchart for explaining a dust detection processing procedure according to the present invention. The document is fed (S1), and the first dust detection (S2) and shading (S3) are performed before reading.
After shading (S3), reading is performed (S4), and it is determined whether the trailing edge of the read document has passed the sheet-through reading position (S5). (S6) Next, shading (S7) is performed. Dust detection and shading are finished before the next document reaches the reading position.
Further, in this method, dust detection can be performed from any position on the white roller 50. Therefore, since dust detection is performed between sheets, reading productivity is not reduced.
Further, while rotating the white bar (white roller) 50, dust detection is performed while the document 52 is being fed. A few lines are read from the white bar 50 rotating at a constant speed to detect dust. For the second sheet, dust detection is performed between the sheets of the document 52. Therefore, it is possible to perform white plate reading for dust detection while the carriage is fixed.
The carriage at the homing position is moved, the reference white plate (reference white) 54 is read, and after homing, the white bar 50 is rotated and read. When the white level difference between the reference white plate 54 and the white bar 50 exceeds the threshold, the white bar 50 Is determined to be dirty.
The dirt of the white bar 50 detected above is displayed as “dirty” on the LCD display of the operation unit, and for example, a message prompting cleaning of the reading unit contact glass 51 is displayed.
In the case of sheet-through ADF document reading, reading productivity is important, but productivity cannot be reduced in order to detect black streaks generated by a piece of paper or the like.
In the present invention, the number of lines necessary for dust detection can be read without moving the carriage by reading the white bar that rotates constantly. Even if the white bar is dirty, it can be detected that the white bar is dirty.
In addition, in the present invention, even if the white bar is dirty, the user may not notice, but when the dust is detected, the LCD display of the operation unit displays “Dirty”. Can be recognized by the user.

1 is an overall configuration diagram illustrating an image reading apparatus according to the present invention. 1 is an overall block diagram showing an image reading apparatus according to the present invention. It is the schematic explaining the original reading by this invention. It is a flowchart explaining the process sequence of the dust detection by this invention.

Explanation of symbols

29 Network operation panel 37 Control unit (CPU)
50 White roller (white bar)
51 Contact Glass 52 Document 53 Sheet-Through Reading Position 54 Reference White

Claims (4)

  An image reading apparatus in a sheet-through ADF has a rotatable white bar in an image reading unit, and detects dust including a piece of paper adhering to a contact glass of the reading unit using a gap between sheets of a document. Image reading device.   2. The image reading apparatus according to claim 1, wherein dust detection is performed by a white bar rotating at a constant speed.   The image reading apparatus according to claim 2, wherein a white level of a white reference white plate and the white bar is read to detect dirt on the white bar.   The image reading apparatus according to claim 3, wherein when the stain on the white bar is detected, the user is notified that the glass portion of the white bar is dirty.

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