JP2010088023A - Manuscript scanning device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to prevent show-through in scanning an image from a manuscript without complicating a structure of a device. <P>SOLUTION: An image scanning unit 9 is provided directly beneath and near a manuscript table 3 and emits and irradiates light to a manuscript 5 placed on the manuscript table 3 and receives the reflected light from the manuscript. A converter 23 converts and outputs electric image data depending on the reflected light received. A moving unit 25 moves the image scanning unit 9 relatively to the manuscript 5. In the process of moving the image scanning unit 9 by the moving unit 25, a scanning controller 29 switches alternately a second scanning state for obtaining first image data as image data based on the reflected light obtained by allowing the image scanning unit 9 to emit light and a second scanning state for obtaining second image data as image data based on the reflected light obtained by reducing light and thus controls the operation of the device. Then, based on the first and second image data, the operator 27 removes and operates the show-through part of the manuscript to obtain image data of the manuscript scanned. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an original reading apparatus and an image forming apparatus, and more particularly to an original reading apparatus that reads an image displayed on an original, and an image forming apparatus such as a copying machine, a facsimile machine, and a multi-function peripheral (MFP) equipped with the original reading apparatus. Regarding improvements.

  Conventionally, in an image forming apparatus provided with this document reading device, when reading an image from the front side of the document, if the document is thin paper, the image recorded on the back side is transparently read together with the surface data. So-called show-through tends to occur.

  Therefore, for example, an image forming apparatus disclosed in Japanese Patent Laid-Open No. 2003-324585 (Patent Document 1) has been proposed.

  In this patent document 1, when reading an image recorded on an original, the original is read while the light source of the contact image sensor is turned on to obtain reflected multi-value image data, and the light source of the contact image sensor is obtained. The transmitted light multi-valued image data is obtained by performing the original reading in a state where the light is turned off, and the reflected light multi-valued image data is obtained in the arithmetic unit based on the reflected light multi-valued image data and the transmitted light multi-valued image data. The multi-valued image data is obtained by removing the image data of the show-through part from the image, and the simple structure prevents the show-through from occurring when reading the double-sided document.

  Further, a document reading device disclosed in Japanese Patent Laid-Open No. 9-135344 (Patent Document 2) has also been proposed.

This patent document 2 measures the light transmittance of an original paper, and when the measured value is larger than a predetermined set value, the back surface of the original paper is irradiated from an LED light source arranged on the back side of the original paper, Scanning is performed twice per line while being turned on (ON) and turned off (OFF) for each line, and level-correction is performed between image data obtained by these scans to remove the show-through component. .
JP 2003-324585 A JP-A-9-135344

  However, in Patent Document 1 described above, the transmitted light multi-value image data when the light source is turned off is based on external light, and the amount of light is not constant or is insufficient, which makes it difficult to perform accurate correction.

  On the other hand, in Patent Document 2, an LED light source disposed behind the original pressure plate is required in addition to the scanning light source that scans image data on the original surface line by line, which increases the number of components and makes the configuration complicated. There was a problem to do.

  Therefore, as a result of diligently examining the thinness of the document, the reflected light, and the intensity of the light source, the present inventor paid attention to the fact that the reflected light due to show-through is greatly reduced if the intensity of the light source is suppressed to some extent. The present invention has been completed.

  The present invention has been made to solve such a problem, and provides an original reading apparatus that suppresses occurrence of show-through when reading an image from an original and does not easily complicate the structure, and an image forming apparatus equipped with the original reading apparatus. With the goal.

  In order to solve such a problem, the document reading apparatus according to claim 1 of the present invention is provided immediately below the document table, emits light toward the document on the document table, and reflects light from the document side. Receiving image reading unit, a conversion unit that converts and outputs electrical image data based on the reflected light received by the image reading unit, and a movement for moving the image reading unit relative to the document in a predetermined direction And image data based on reflected light obtained by causing the image reading unit to emit light with respect to an image at the same position recorded on the document in the process in which the moving unit relatively moves the image reading unit. Second image data as image data based on the first reading state for obtaining the first image data and the reflected light obtained by dimming from the first reading state and emitting the image reading unit. To get the second reading state A reading control section for example operation control, and includes a calculation unit which is removed calculating the show-through portion of the document based on the their first image data and second image data obtaining the read image data.

  In the document reading apparatus according to claim 2 of the present invention, in the process in which the reading control unit moves the image reading unit, the reading control unit alternates between the first and second reading states in each scanning line of the document. The switching operation is controlled.

  In the document reading apparatus according to claim 3 of the present invention, the reading control unit controls the light emission amount of the second reading state to be reduced to 2/3 to 1/3 of the light emission amount of the first reading state. It has a configuration.

  According to a fourth aspect of the present invention, there is provided a document reading device directed toward the back of the document so as to block the irradiation light from the image reading unit on the side opposite to the image reading unit with the document on the document table in between. It has a configuration having an original platen arranged.

  According to a fifth aspect of the present invention, there is provided a document reading device in which the reading control unit controls the light emission amount in the second reading state to be dimmed according to the thickness of the document.

  An image forming apparatus according to a sixth aspect of the present invention includes any one of the document reading apparatuses and includes an image forming unit that forms an image of the read image data.

  In such a document reading apparatus according to the first aspect of the present invention, light is emitted and emitted toward the document on the image reading unit and reflected light from the document side, and the conversion unit is electrically connected based on the reflected light. In the process in which the image data is converted and output, and the moving unit moves the image reading unit relative to the document, the reading control unit applies the image reading unit to the image at the same position recorded on the document. A first reading state for obtaining first image data as image data based on reflected light obtained by emitting light, and reflected light obtained by causing the image reading unit to emit light by dimming from the first reading state Switching operation control between the second reading state for obtaining the second image data as the image data based on the image data, and the calculation unit removes the show-through portion of the document based on the first image data and the second image data. Calculate the scanned image data So is easy to suppress the occurrence of show-through when reading an image from a document, it is difficult even to complicated configurations.

  In the document reading apparatus according to claim 2 of the present invention, the reading control unit changes the first and second reading states in each scanning line of the document in a process in which the moving unit moves the image reading unit. Since the switching operation is controlled alternately, it is easy to speed up the output of the read image data.

  In the document reading apparatus according to a third aspect of the present invention, the reading control unit controls the light emission amount in the second reading state to be reduced to 2/3 to 1/3 of the light emission amount in the first reading state. Therefore, it is possible to reliably suppress the occurrence of show-through.

  In the document reading apparatus according to claim 4 of the present invention, the document is placed on the side opposite to the image reading unit with the document on the document table in between so as to block the irradiation light from the image reading unit. Therefore, the occurrence of show-through can be more reliably suppressed.

  In the document reading apparatus according to claim 5 of the present invention, the reading control unit controls the light emission amount of the second reading state in accordance with the thinness of the document, and accordingly, according to the thinness of the document. It is possible to reliably suppress the occurrence of show-through.

  The image forming apparatus according to the sixth aspect of the present invention includes any one of the document reading devices and includes an image forming unit that forms an image of the read image data, thereby suppressing occurrence of show-through. It is easy to form image data.

  Embodiments of a document reading apparatus and an image forming apparatus according to the present invention will be described below with reference to the drawings.

  First, the document reading apparatus A according to the present invention will be described.

  FIG. 1 is a block diagram showing an embodiment of a document reading apparatus A according to the present invention.

  In FIG. 1, a main body case 1 also serves as a main body case of an image forming apparatus B described later, and a transparent contact glass 3 is disposed on the upper side. The contact glass 3 is formed in a square shape larger than the size of the original 5 to be read, and functions as an original table on which the original 5 is placed.

  The manuscript pressure plate 7 is a white plate that is pressed on and over the manuscript 5 superimposed on the contact glass 3. The end portion is fixed to the main body case 1 by a hinge mechanism (not shown) and can be displaced in a fan shape. Yes.

  In the main body case 1, an image reading unit 9 that emits light toward the document 5 placed on the contact glass 3 and receives reflected light from the document side is formed immediately below the contact glass 3. ing.

  As shown in FIG. 2, the image reading unit 9 stores a light source 11 including a light emitting diode that emits light toward the document 5, a mirror 13 that reflects reflected light from the contact glass 3 side, and these. A storage unit 15 is provided and is unitized.

  In the main body case 1, mirrors 17 and 19, a condenser lens 21, and a conversion unit 23 are arranged on the optical axis of the reflected light from the mirror 13 to form an optical system, as shown in FIG. .

  The image reading unit 9 is connected to a moving unit 25 disposed inside the main body case 1, and immediately below the contact glass 3 and in parallel with the contact glass 3, this one end (the left end in the figure) is the starting end. The moving unit 25 is controlled to reciprocate so as to intermittently move at a predetermined timing toward the other end (right end in the figure) that is the end, and to return toward the start when the end is reached.

  The light source 11 of the image reading unit 9 reads an image of the document 5 placed on the contact glass 3 for each scanning line, and the amount of light is variably controlled. The light quantity variable control will be described later.

  The conversion unit 23 is made up of, for example, a CCD (charge coupled device), guided by mirrors 17 and 19, and based on the reflected light from the image reading unit 9 collected by the condenser lens 21. The image data digitally converted into a value electric signal is output to the calculation unit 27.

  In the process in which the moving unit 25 moves the image reading unit 9, the reading control unit 29 causes the light source 11 to emit light with the maximum light amount with respect to the image at the same position recorded on the document 5, and thereby the light source 11. It has a function of controlling the operation by alternately switching between the light emission state in which the light amount is reduced to ½ and the light is emitted.

  That is, the reading control unit 29 controls the moving unit 25 so that the image reading unit 9 moves intermittently while temporarily stopping with respect to the document 5 for each scanning line, and causes the light source 11 to emit light with the maximum light amount. A first reading state for obtaining first image data as image data based on the reflected light, and reflected light obtained by reducing the light amount of the light source 11 to ½ and emitting light by emitting light from the first reading state. For controlling the light source 11 so as to alternately switch the second reading state in which the second image data as the image data based on the image reading unit 9 is temporarily stopped (for each scanning line). have.

  The calculation unit 27 has a calculation function for obtaining read image data by removing a show-through portion of the document 5 based on the first image data and the second image data output from the conversion unit 23. It is connected to a print control unit 31 of an image forming apparatus B described later.

  In general, as shown in FIG. 3, the light emitting diode forming the light source 11 of the image reading unit 9 has a change larger than the decrease change amount of the drive current in the vicinity of the intermediate value where the drive current applied to the light source 11 is reduced to some extent from the maximum value. The amount of emitted light (light intensity) decreases with the amount.

  Since the amount of light directly reflected from the front surface of the document 5 itself is large, the maximum value and the intermediate value do not decrease suddenly even if the amount of emitted light is reduced to some extent, while passing through the document 5 and the back surface. The amount of reflected light reflected from the light abruptly decreases from the maximum value to the intermediate value.

  For example, as shown in FIG. 4A, reference numeral “123” is an image on the front side of the document 5, and reference numeral “<*>” is an image on the back side of the document 5, and the front surface at the position P in FIG. When the level of the image data on the side is as shown in FIG. B, the level of the image data on the back side at the position P in FIG. A is as shown in FIG. As shown in D, the waveform has an enhanced level of image data on the front side. If the threshold value P ′ is appropriately selected, only the image data from the surface of the document 5 can be extracted and the show-through portion of the document 5 can be removed.

  For example, the calculation unit 27 adds the first image data and the second image data output from the conversion unit 23, and uses only image data that exceeds a predetermined large threshold value P ′ as image data for image formation. It has a function of outputting to the forming apparatus B.

  Next, the operation of the document reading apparatus A according to the present invention will be briefly described.

  The original pressure plate 7 is lifted and opened to place a thin original 5 on the contact glass 3, and after the original pressure plate 7 is closed again, a reading key (not shown) is operated to start a reading operation.

  Then, the reading control unit 29 performs intermittent movement control of the image reading unit 9 at a predetermined timing via the moving unit 25, and the image reading unit 9 repeats a temporary stop for each line with respect to the document 5, Move intermittently from the end toward the end.

  Then, while the image reading unit 9 is temporarily stopped, the reading control unit 29 controls the light emission of the light source 11 with the maximum light amount, and controls the light emission by reducing the light source 11 to ½ the light amount. The switching operation is controlled alternately for each line, and the reflected light received by the image reading unit 9 is guided to the conversion unit 23.

  Therefore, from the conversion unit 23, for each scanning line, the first image data having a level based on the reflected light obtained by emitting the maximum amount of light and the second image data having a level based on the reflected light obtained by dimming. The image data is output to the calculation unit 27.

  In the arithmetic unit 27, when the first image data and the second image data are added and data exceeding a predetermined threshold is output, image data for image formation from which the show-through portion of the document 5 is removed is obtained.

  When the image reading unit 9 reaches the end, the moving unit 25 reciprocates the image reading unit 9 so as to return toward the starting end, and the reading operation ends.

  Next, an image forming apparatus B equipped with the above-described document reading apparatus A will be briefly described with reference to FIG.

  The image forming apparatus B includes the document reading apparatus A, the storage unit 33, the operation panel unit 35, the printing unit 37, and the transmission / reception unit 39 described above with the print control unit 31 as the center, and constitutes, for example, a multifunction peripheral (MFP). ing. The image forming apparatus B has a configuration other than this, but since it is not the gist of the present invention, description and illustration are omitted.

  The document reading apparatus A is a scanner that optically reads an image from the document 5 and generates image data from which the show-through portion is removed as described above, and is under the control of the reading control unit 29 and the like by the print control unit 31. The image data for each page is stored in the storage unit 33.

  The storage unit 33 stores read image data from the document reading apparatus A and received image data to be described later from the transmission / reception unit 39 under the control of the print control unit 31, as well as read / write that stores an operation program of the print control unit 31. Possible, for example, a hard disk.

  Although not shown, the operation panel unit 35 is arranged on the upper part of the main body case 1 and is a known liquid crystal display panel as a display unit capable of displaying various operation states under the control of the print control unit 31. It has a function as an input unit that accepts reading from a document by touching a place where an image related to the operation is displayed.

  The printing unit 37 is arranged in the main body case 1 shown in FIG. 1 described above, and although not shown, a plurality of paper feeding units on which sheet materials are set and the above-described image data are expanded into print image image data. A color or monochrome printing engine as an image forming unit having a transfer unit that develops toner with toner from a toner cassette and transfers a toner image to a sheet material, and a fixing unit that fixes a transferred image of the transferred sheet material. .

  The transmission / reception unit 39 is an interface unit that transmits / receives various information to / from the information processing apparatus 43 such as a computer via the network 41 in accordance with a predetermined protocol.

  The print control unit 31 includes a CPU and a ROM that stores an operation program for the CPU. The print control unit 31 includes the document reading device A, the storage unit 33, the operation panel unit 35, the reception unit 9, the printing unit 37, and the like described above. The transceiver unit 39 and the like are controlled, and a function unit (not shown) of the multifunction peripheral is controlled.

  As described above, the document reading apparatus of the present invention is provided immediately below the contact glass (document table) 3 and emits light toward the document 5 on the contact glass 3 and receives reflected light from the document side. A reading unit 9; a conversion unit 23 that converts and outputs electrical image data corresponding to the reflected light received by the image reading unit 9; and a moving unit 25 that moves the image reading unit 9 in the direction of the document 5. In the process in which the moving unit 25 moves the image reading unit 9, first image data as image data based on reflected light obtained by causing the image reading unit 9 to emit light for each scanning line of the document 5. A first reading state for obtaining image data, and a second reading state for obtaining second image data as image data based on reflected light obtained by dimming light from the first reading state and causing the image reading unit to emit light And alternately A read control unit 29 for controlling, and a calculator 27 for obtaining the read image data by removing calculating the show-through portion of the document based on their first image data and second image data.

  Therefore, when reading the document 5, the image is read with the normal light amount and the dimmed light amount for each scanning line, and the image data directly reflected from the front surface of the document 5 and the light reflected from the back surface through the document. Since the difference from the image data is calculated and the show-through removal process is performed to extract only the front image, it is easy to suppress the occurrence of show-through when reading the image from the document. Therefore, it is difficult to make the configuration complicated.

  In addition, since the first and second reading states are alternately switched for each scanning line of the document 5, it is easy to speed up the output of the read image data, and the light emission amount in the second reading state. Is controlled to be reduced to half the light emission amount in the first reading state, so that occurrence of show-through can be reliably suppressed.

  However, the document reading apparatus A of the present invention is not limited to the first and second reading states for each scanning line of the document 5, that is, the configuration in which the light quantity of the light source 11 is switched and variable. A configuration is also possible in which after reading in the reading state, the image reading unit 9 is moved back to the original start position and then moved again to read in the second reading state.

  Further, the light amount of the light source 11 of the image reading unit 9 is not limited to the configuration in which the light amount is controlled to be reduced to 1/2 of the maximum light amount as described above, and the light emission is performed by reducing the light amount to about 2/3 to 1/3. By doing so, the object of the present invention can be achieved. If the light is reduced too much, the image data from the surface of the document 5 is not emphasized.

  In the above-described document reading apparatus A, the document 5 on the contact glass 3 is placed on the back side of the document so as to block the irradiation light from the light source 11 of the image reading unit 9 on the side opposite to the image reading unit 9. Since the original pressure plate 7 is directed, it is possible to more reliably suppress the occurrence of show-through.

  Incidentally, in the above-described document reading apparatus A of the present invention, the light emission amount of the light source 11 of the image reading unit 9 is automatically reduced to ½ of the maximum light amount. In this case, a configuration in which the thickness of the document 5 is detected and the light emission amount in the second reading state is controlled to be dimmed according to the thickness of the document 5 as a detection result is possible. The portion 29 may be formed.

  In such a configuration, occurrence of show-through can be reliably suppressed according to the thinness of the document 5.

  Furthermore, in the document reading apparatus of the present invention described above, the image reading unit 9 is moved with respect to the document 5 on the contact glass 3. However, in the present invention, the image reading unit 9 is fixed and is not illustrated. A configuration in which the document 5 is moved by a moving unit such as a roller is also possible. The point is that the image reading unit 9 may be moved relative to the document 5.

  In the image forming apparatus B according to the present invention, in addition to the effects related to the document reading apparatus A described above, image formation of image data with suppressed occurrence of show-through is easy.

1 is an internal configuration diagram showing an embodiment of a document reading apparatus according to the present invention. 1 is a schematic configuration diagram showing a main part of a document reading apparatus according to the present invention. It is a figure explaining the light source characteristic of the original document reading apparatus concerning this invention. It is a figure explaining operation | movement of the original document reading apparatus which concerns on this invention. 1 is a block diagram showing an image forming apparatus equipped with a document reading apparatus according to the present invention.

Explanation of symbols

1 Body case 3 Contact glass (original platen)
5 Document 7 Document platen 9 Image reading unit 11 Light source 13, 17, 19 Mirror 15 Storage unit 21 Condensing lens 23 Conversion unit 25 Moving unit 27 Calculation unit 29 Reading control unit 31 Print control unit 33 Storage unit 35 Operation panel unit 37 Printing (Image forming unit)
39 Transmission / Reception Unit 41 Network 43 Information Processing Device (Computer)
A Document reading apparatus B Image forming apparatus

Claims (6)

An image reading unit that is provided immediately below the document table, emits light toward the document on the document table, and receives reflected light from the document side;
A conversion unit that converts and outputs electrical image data based on the reflected light received by the image reading unit;
A moving unit that moves the image reading unit relative to the document in a predetermined direction;
In the process in which the moving unit relatively moves the image reading unit, as the image data based on the reflected light obtained by causing the image reading unit to emit light with respect to the image at the same position recorded on the document. Second image data as the image data based on the first reading state in which the first image data is obtained and the reflected light obtained by causing the image reading unit to emit light by dimming from the first reading state A reading control unit for controlling the switching operation of the second reading state to obtain
A calculation unit that obtains read image data by removing a show-through portion of the document based on the first image data and the second image data;
An original reading apparatus comprising: The document reading unit according to claim 1, wherein the reading control unit controls the switching operation between the first and second reading states alternately in each scanning line of the document in a process in which the moving unit moves the image reading unit. apparatus. 3. The document reading apparatus according to claim 1, wherein the reading control unit performs dimming control of the light emission amount in the second reading state to 2/3 to 1/3 of the light emission amount in the first reading state. 2. A document pressure plate disposed toward the back side of the document so as to block the irradiation light from the image reading unit on the side opposite to the image reading unit with the document on the document table interposed therebetween. 3. The document reading device according to any one of 3. The document reading apparatus according to claim 3, wherein the reading control unit performs dimming control on the light emission amount in the second reading state in accordance with the thinness of the document. 6. An image forming apparatus comprising the original reading apparatus according to claim 1, further comprising an image forming unit that forms an image of the read image data.

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