JP2007228032A - Image reader and image forming apparatus equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader and an image forming apparatus in which punching hole can be eliminated easily and surely with low cost without adding any special processing or complex mechanism to the apparatus. <P>SOLUTION: The image reader comprising a platen glass for mounting a document, an opening/closing platen cover covering the platen glass, and an image reading section for reading the image of a document mounted on the platen glass. It is further provided with a means for reading the image of a document mounted on the platen glass while opening the platen cover and detecting the end of document from the document image thus read out by the difference of intensity and saturation between the inside and the outside of the document, and a control means for reading out the image of a document mounted on the document mounting section while opening the platen cover, detecting a punch hole on the inside of the document end by the difference of intensity and saturation between the inside of the document and the punch hole and then eliminating the punch hole. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reliably erases punch holes in an original and an image forming apparatus including the image reading apparatus.

  In conventional image reading apparatuses and image forming apparatuses (copiers, facsimiles, multifunction machines, etc.), when a hole for filing or the like is punched in an original, the image reading apparatus assumes that the punch hole portion has an image. In this case, the shadow of the punch hole of an unnecessary and annoying document unintended for the operator is formed on the sheet as it is. Further, when a large number of copies are taken, there is a problem that wasteful toner consumption occurs remarkably and wasteful expenses are wasted. Further, there may be a case where the original must be set again and the copy must be performed again so that the shadow of the punch hole is not formed on the sheet as it is.

  Therefore, in order to solve the problem, the punch hole pattern is discriminated from the document reading data by the scanner with the punch hole pattern stored in the storage means, or the document pressure plate sheet or the document conveying belt is determined from the document reading data by the scanner. In some cases, the punch hole is discriminated based on the image data level, and the image data of the punch hole is erased or hollowed out. (For example, refer to Patent Document 1).

  In addition, a bookbinding document having punch holes or the like in the vicinity of the binding portion by forming the upper surface of the document table in a predetermined range as a light-colored portion near the end portions on the adjacent sides of the left and right document tables and making the other portions black Even when the image is read, the bright color portion on the document table is exposed from the punch hole, and the punch hole is not formed as a black circle in the read image (for example, see Patent Document 2).

In addition, a back sheet of a color with a small density difference between the original and the color is attached to the original facing surface of the cover placed on the original placed on the platen glass so that it can be moved up and down. In some cases, the edge of the original can be easily detected by being incident, and if it is lowered during the reading scan, the punch hole portion does not become black. (For example, refer to Patent Document 3).
Japanese Patent Laid-Open No. 9-9041 (FIGS. 5, 8, and 9) Japanese Patent Laid-Open No. 11-220605 (FIG. 11) Japanese Patent Laid-Open No. 2001-69317 (FIGS. 1 and 2)

  However, the following problems occur in the conventional technology.

  When discriminating punch holes by comparing original reading data by the scanner with punch hole patterns stored in the storage means, storage means for storing the punch hole patterns is required and stored in the storage means. There is a problem that it is difficult to perform a process of discriminating a punch hole by collating with a punch hole pattern and it is easy to make a false detection.

  Further, when the punch hole is discriminated based on the image data level of the original pressure plate sheet or the original conveying belt from the original reading data by the scanner, the image data level of the original pressure plate sheet or the original conveying belt is distinguished from the original image data level. There is a problem that special light color processing is required for the original platen sheet or the original conveying belt. Furthermore, when the upper surface of the original plate in a predetermined range is formed as a light color portion near the end on the adjacent side of the left and right original plates, and the other portion is a black portion, it is necessary to specially process the upper surface of the original plate, There has been a problem that the apparatus becomes complicated and the cost increases.

  On the other hand, if a back sheet of a color with a small density difference between the original and the color is attached to the cover opposite to the original placed on the original placed on the platen glass so that it can be raised and lowered, and the cover is raised when pre-scanning and lowered during scanning Therefore, it is necessary to attach a back sheet of a color having a small color density difference between the original and the original so that it can be moved up and down, which complicates the apparatus and increases the cost.

  That is, since the conventional technique adds a special processing process or a complicated mechanism, there is a problem that the punch hole cannot be erased easily and reliably at low cost.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is capable of easily and reliably erasing punch holes at low cost without adding special processing or complicated mechanisms to the apparatus. It is another object of the present invention to provide an image forming apparatus including the same.

  The present invention includes a document placement section for placing a document, an openable / closable cover for covering the document placement section, and an image reading section for reading a document image placed on the document placement section. Document edge detection in which the image reading unit reads an image of the document placed on the document placing unit with the cover open, and detects and stores the document edge based on the brightness and saturation difference in the read image. The image of the document placed on the document placement unit with the storage means and the cover open is read by the image reading unit, and the brightness and color in the document region defined by the document edge in the read image Control means for detecting a punch hole based on the degree difference and erasing the punch hole is provided.

  According to the image reading apparatus and the image forming apparatus of the present invention, punch holes can be erased easily and reliably at low cost without adding special processing or complicated mechanisms to the apparatus.

  An image reading apparatus according to a first aspect of the present invention includes a document placing portion on which a document is placed, an openable / closable cover that covers the document placing portion, and a document image placed on the document placing portion. An image reading unit that reads an image of a document placed on the document placing unit with the cover open, and reads the image based on the brightness and saturation difference in the read image. Document edge detection storage means for detecting and storing the edge, and an image of the document placed on the document placing portion with the cover open, is read by the image reading portion, and is defined by the document edge in the read image. And a control means for detecting a punch hole based on the brightness and saturation difference in the original area and erasing the punch hole.

  According to this, the image of the document placed on the document placement portion is read with the cover open, and the brightness and saturation difference in the read image (that is, the brightness and saturation corresponding to the inside of the document area and the outside of the document area). The edge of the document is detected based on the difference in saturation. Next, the image of the document placed on the document placement unit is read with the cover open again, and the brightness and saturation difference (in the document area defined by the document edge detected by the previous document image reading) ( That is, the punch hole is detected by the difference in lightness and saturation corresponding to the punch hole portion and the other normal image portion), and the punch hole is erased. The punch hole can be erased easily and surely at low cost using only an existing apparatus without adding.

  An image reading apparatus according to a second aspect of the present invention further comprises punch hole position storage means for previously storing position information of punch holes that can be formed in the document area in the first aspect of the present invention. The control means detects the punch hole from an area that matches the position information of the punch hole.

  According to this, the image of the document placed on the document placement portion is read with the cover open, and the document edge is detected based on the brightness and saturation difference in the read image. Next, the image of the document placed on the document placement portion is read with the cover open again, and the brightness and saturation difference are determined in the document area defined by the document edge and in the area matching the punch hole position information. Since the punch hole is detected by this, the punch hole is erased. Therefore, the punch hole can be erased easily and reliably at low cost only with an existing device without adding special processing or complicated mechanisms to the device. be able to.

  Further, since the punch hole is detected based on the position information of the punch hole inside the original image, it is possible to prevent erroneous detection of image data having the same brightness and saturation as the punch hole outside the punch hole position information.

  An image reading apparatus according to a third aspect of the present invention is characterized in that the punch hole position information in the second aspect of the present invention is information on a region extending from a document edge to a predetermined range. is there.

  According to this, since the punch hole position information is limited to an area where a normal punch hole can exist (a predetermined range including a position where the punch hole may be formed from the document edge), the punch hole is more reliably detected. It is possible to prevent erroneous detection of image data having the same brightness and saturation as the punch holes.

  The image reading apparatus according to the fourth aspect of the present invention performs the punch hole erasing process according to any one of the second and third aspects of the present invention within a predetermined range including the detected punch hole. It is characterized by this.

  According to this, by performing the punch hole erasing process within a predetermined range including the punch hole, the punch hole erasing process including the punch hole and the shadow portion of the punch hole can be more reliably performed.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIGS. 1A and 1B are perspective views showing the appearance of the image forming apparatus according to the present embodiment. FIG. 1A is an external perspective view showing a state in which the platen cover 104 of the image forming apparatus 100 is opened. In FIG. 1A, an image forming apparatus 100 inputs an apparatus main body 101 including a recording paper storage unit, a recording paper conveyance unit, an image forming unit, an image fixing unit, and the like, and various instructions related to image formation. An operation panel 102 that displays instruction content, an image reading unit 103 that forms a reading surface on which a document is placed, and that includes an image reading processing unit that reads an image printed on the document placed on the reading surface; The platen cover 104 and the like that can be opened and closed to cover the reading surface.

  FIG. 1B is an external perspective view showing the image reading unit 103 and the platen cover 104 of FIG. In FIG. 1B, a platen glass 105 made of transparent glass that covers the reading range of the image reading unit 103 is attached to the reading surface on which the original and book original of the image reading unit 103 are placed. An open / close detection sensor 106 for detecting the open / closed state of the platen cover 104 is provided on the rear side of the holding frame for holding the platen glass 105 in the drawing.

  A plurality of document size detection sensors 107 for detecting the document size are arranged on the back side (back surface) of the reading surface of the platen glass 105. The shape of the platen glass 105 shown in FIG. 1B is a rectangle, its short side is the reading range in the main scanning direction of the image reading unit 103, and its long side is in the sub-scanning direction of the image reading unit 103. This is the reading range.

  Next, a configuration of a control system built in the apparatus main body 101 of the image forming apparatus 100 will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the control system. 2, the control system of the image forming apparatus 100 includes a CCD line sensor 201, an A / D converter 202, a change point detection circuit 203, a change point storage memory 204, an image mask circuit 205, and an image processing circuit. 206, an image output unit 207, a control operation unit 208, and a control circuit unit 209.

  Hereinafter, a color machine will be described as the image forming apparatus 100, but the present invention can be similarly applied to a monochrome machine. The present invention can also be applied to an image reading apparatus that includes a control system excluding the image output unit.

  A CCD (Charge Coupled Devices) line sensor 201 is composed of a CCD line sensor for one line that covers the main scanning range which is the short side of the platen glass 105. The CCD line sensor 201 is scanned in the sub-scanning direction according to the size of the document placed on the platen glass 105 by a scanning mechanism (not shown). A color image printed on an original is read in three colors of R (red), G (green), and B (blue) for each line with a main scanning width, and R, G, and B images read for each line are R , G, B image signals are output to the A / D converter 202.

  The A / D converter 202 converts the R, G, and B image signals input for each line from the CCD line sensor 201 into digital data corresponding to the change in the number of gradations of each color, and changes the converted image signal. It outputs to the point detection circuit 203. The change point detection circuit 203 detects the coordinates of each change point of lightness and saturation in the document from the image signal input from the A / D converter 202, and stores the coordinates in the change point storage memory 204.

  The image mask circuit 205 performs mask processing on the image signal input from the change point detection circuit 203 and outputs the image signal to the image processing circuit 206. The output image processing circuit 206 performs image processing on the image signal input from the image mask circuit 205 in the order of shading correction processing and gamma correction processing, and outputs the image signal after the image processing to the image output unit 207.

  The image output unit 207 controls operations of a printer memory that stores one page of the image signal input from the image processing circuit 206 and an image forming unit (not shown) that prints the image signal stored in the printer memory. Consists of a printer controller and the like. The control operation unit 208 outputs an instruction signal to the control circuit unit 209 in response to various instructions related to image formation input from the operation panel 102 of FIG. 1, and displays the instruction content input from the control circuit unit 209 as a display signal. Is output to the operation panel 102 to display the instruction content.

  The control circuit unit 209 includes a CPU (Central Processing Unit) 210, a RAM (Random Access Memory) 211, and a ROM (Read Only Memory) 212. The CPU 210 controls operations related to image formation of the respective units based on an image formation control program stored in the ROM 212. In addition, the CPU 210 calculates punch hole coordinates on the document by a punch hole detection processing program stored in the ROM 212 and erases the punch holes on the document by setting a punch hole mask pattern in the image mask circuit 205. Create an image signal. This punch hole erasing process is performed within a predetermined range including the detected punch hole, so that the erasing process including the shadow portion around the punch hole can be more reliably performed.

  The RAM 211 is used as a work memory for developing the processing programs and temporarily storing various parameters to be processed when the CPU 210 executes the processing. The ROM 212 stores the image formation control program and the punch hole detection processing program.

  Here, an output image of a document having punch holes before the present invention and an example in which the influence of punch holes is removed from the output image by the effect of the present invention will be described with reference to FIG. FIG. 3A shows a state in which a document with punch holes is placed on the platen glass 105 with the platen cover 104 opened.

  When an original with punch holes is read and an image is formed by an existing process in which the present invention is not carried out, an output image with black punch holes as shown in FIG. 3B is obtained. It is done. FIG. 3C shows an example in which the punch hole of the original is masked and removed from the output image by carrying out the present invention.

  In the example of FIG. 3, the case where there are two punch holes on one side of the document is taken as an example. However, in the present invention, the number of punch holes is not limited, and a punch is formed on the opposite document end of the example of FIG. Even when there is a hole or when there are punch holes on both the left and right edges of the document, it is possible to obtain an output image with the punch holes masked.

  Here, an image signal level obtained from a document with a punched hole and coordinate information detected based on the image signal level will be described with reference to FIGS. FIG. 4A shows a state in which a document with punch holes is placed on the platen glass 105 with the platen cover 104 opened.

  FIG. 4B is an enlarged view around the punch hole in FIG. The document including punch holes is scanned in the sub-scanning direction by the CCD line sensor 201 and the scanning mechanism. The number of lines in the sub-scanning direction at this time is shown as Y line, Y1 line, Y2 line, Y3 line, and Y4 line in FIG. The image signal levels in each sub-scan line are shown in FIGS. 5 (a), (b), and (c). As is clear from FIGS. 5A, 5B, and 5C, the image signal level scanned with the platen cover 104 opened decreases in the output level outside the document or at the punch hole portion. . The output level of the image signal level in the original increases.

  The change point detection circuit 203 detects the difference between the image signal levels, and outputs the coordinate information when detecting the difference between the constant image signal levels. The change point storage memory 204 stores the coordinate information of the change point output from the change point detection circuit 203. FIG. 6 shows the coordinate information stored in the change point storage memory 204.

  Here, the punch hole detection range and the punch hole recognition range will be described with reference to FIG. A punch hole is recognized as being within a certain range from the right end of the document or the left end of the document. This fixed range is a range indicated by A (punch hole detection range) in FIG. 7, and the range of A in FIG. 7 is expressed by a numerical value, and the numerical value is stored in the ROM 212.

  Moreover, what is recognized as a punch hole is within a certain range. These ranges are a (punch hole recognition range main scan) and b (punch hole recognition range sub-scan) in FIG. 7, and the ranges of a and b in FIG. Is done.

  When the CPU 210 executes the punch hole detection program, the numerical values representing A, a, and b in FIG. 7 are read from the ROM 212 and used for punch hole detection processing.

  Hereinafter, description will be made with reference to FIGS. The user operates a copy start key provided on the operation panel 102 when starting the document image reading process. When a copy start instruction is input from the operation panel 102, the control operation unit 208 outputs the instruction signal to the control circuit unit 209 (S001).

  When a copy start instruction signal is input, the CPU 210 of the control circuit unit 209 reads a document image forming processing program stored in the ROM 212, develops it in the RAM 211, and starts processing. The CPU 210 determines whether or not the platen cover 104 is open based on the detection signal input from the open / close detection sensor 106 (S002). When the CPU 210 determines that the platen cover 104 is in the closed state, the normal reading is not performed in the open document reading mode that is executed while the platen cover 104 is opened, but is read by placing the document on the platen glass 105 with the platen cover 104 closed. It is determined that the mode is selected, and the normal reading mode is entered (S006).

  If the CPU 210 determines that the platen cover 104 is open, the CPU 210 shifts to the pre-read mode (S003). In the pre-reading mode, the operation of the scanning mechanism is controlled to scan the reading surface of the platen glass 105 in the sub-scanning direction, and the image of the document placed on the reading surface is read by the CCD line sensor 201. At this time, the CCD line sensor 201 reads a punch hole together with the document image, and outputs a document image signal including the punch hole to the A / D converter 202.

  The A / D converter 202 converts the input document image signal into digital data corresponding to the change in the number of gradations, and outputs the converted image signal to the change point detection circuit 203. The change point detection circuit 203 detects a change point of brightness and saturation of the image signal, and stores the coordinates in the change point storage memory 204. The change point coordinates of the image signal stored in the change point storage memory 204 include the coordinates of the punch holes as well as the left and right end coordinates of the document edge.

  Next, the CPU 210 reads the punch hole detection processing program, expands it in the RAM 211, and starts the detection processing (S004). In this detection processing, as shown in FIGS. 9 and 10, the detection processing is executed in order of punch holes in the order of the left end side and the right end side of the document (S101). First, the coordinates of the document edge are searched to determine the document edge (S102 or S103). Next, a range A (according to punch hole position information) that is set as a rectangular area inside the document from the document edge detected in the above process and including the punch edge shown in FIG. The coordinates in the punch hole detection range) are extracted and set as a coordinate group L or R (S104 or S105).

  Next, from the coordinate group L or R, the coordinates where the proximity coordinates fall within the range a: punch hole recognition range (main scanning) and b: punch hole recognition range (sub scanning) shown in FIG. 7 are extracted, These are set as coordinate groups L # p1, L # p2,... Or R # p1, R # p2,... (S106 or S107), the number of coordinates included in each coordinate group is counted, and the count result is counted as a. (S108, S109), and for each coordinate, the coordinates that are on one straight line with the close coordinates or on the same arc are extracted, the number of coordinates is counted, and the count result is set to count b (S112 or S109). S113).

  If the ratio of the count a and the count b is equal to or greater than a predetermined ratio (70% or more in the present embodiment) using the count result, the image area including the coordinate group L or R is a punch hole. If the ratio between the count a and the count b is less than a predetermined ratio, it is determined that the image area composed of the coordinate group L or R is not a punch hole (S117 or S118). S119). Punch hole mask information is created from the coordinate group L determined to be a punch hole (S120). Subsequently, punch hole mask information is created from the coordinate group R determined to be a punch hole (S121). The punch hole mask information is information of a tangent line that circumscribes the coordinate group L.

  Next, the CPU 210 sets punch hole mask information created by the above processing in the image mask circuit 205. As shown in FIG. 8, the punch hole mask information is set in the image mask circuit 205, and the process is terminated (S005).

  Next, the original image forming processing program stored in the ROM 212 is read out and expanded in the RAM 211, and the following processing is started (S006). The CPU 210 controls the operation of the scanning mechanism, scans the reading surface of the platen glass 105 in the sub-scanning direction, and causes the CCD line sensor 201 to read the image of the document placed on the reading surface.

  The CCD line sensor 201 reads a punch hole together with the original image, and outputs an original image signal including the punch hole to the A / D converter 202. The A / D converter 202 converts the input document image signal into digital data corresponding to the change in the number of gradations, and outputs the converted image signal to the change point detection circuit 203. The image mask circuit 205 masks the punch hole image from the image signal input from the change point detection circuit 203 based on the punch hole mask information set by the above processing, and outputs the image signal.

  Processing performed in the image mask circuit will be described with reference to a timing chart shown in FIG. FIG. 11A is a diagram illustrating a specific example of document image data including punch holes, and FIG. 11B is a diagram illustrating a specific example of mask information calculated by the CPU 210. Based on the set mask information, the image mask circuit 205 masks the punched holes of the input image data shown in FIG. 5A and outputs the output image shown in FIG.

  The image signal masked with the punch holes output from the image mask circuit 205 is input to the image processing circuit 206, and the image processing circuit 206 performs image processing in the order of shading correction processing and gamma correction processing. Is output to the image output unit 207. The image output unit 207 accumulates the image signal from the image processing circuit 206 in the printer memory, and controls the operation of the image forming unit (not shown) based on the image signal accumulated in the printer memory by printer control to record on the recording paper. Print the image.

  As a result of the above processing, in the open document reading mode in which external light is incident on the platen glass 105, even when the document image is read together with the punch hole, it is possible to read the actual document image with the punch hole removed. That is, the punch hole is masked from the original image including the punch hole of FIG. 11A, and the image data shown in FIG. 11C can be output.

  As described above, the image forming apparatus according to the present embodiment detects the coordinate information of the punch hole from the image signal by using the open document reading mode in which the platen cover is opened and the book document or the like having the punch hole is read. Then, a mask signal for a punch hole is generated by analyzing the program using a program executed by the CPU.

  Therefore, in the image forming apparatus according to the present embodiment, when reading a document by opening the platen cover and reading a document image, the coordinates of the punch holes are detected and the punch holes are identified. Since it can be realized by adding a processing program without adding a mechanism, the function and reliability of the image forming apparatus can be improved at low cost.

  The present invention eliminates the influence of punch holes without requiring the addition of a new sensor or mechanism, and can reliably read a document image, and can be applied to image forming apparatuses such as facsimiles and printers.

1 is an external perspective view of an image forming apparatus according to an embodiment of the present invention, (a) is an external perspective view of the entire apparatus, and (b) is an external perspective view of the upper part of the apparatus. A block diagram showing a configuration of a control system of the image forming apparatus according to the embodiment. The figure which shows the specific example of the punch hole original image which concerns on the said embodiment. The figure which shows the specific example of the punch hole coordinate which concerns on the said embodiment. The figure which shows the image signal level in each sub-scanning line The figure which shows the mode of the coordinate information memorize | stored in the change point memory 204 The figure which shows the punch hole detection range which concerns on the said embodiment Flowchart of overall control according to the above embodiment Flow chart of punch hole detection control according to the above embodiment Flow chart of punch hole detection control according to the above embodiment The figure which shows the specific example of the punch hole mask control which concerns on the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Apparatus main body 102 Operation panel 103 Image reading part 104 Platen cover 105 Platen glass 106 Opening / closing detection sensor 107 Original size detection sensor 201 CCD line sensor 202 A / D converter 203 Change point detection circuit 204 Change point memory 205 Image mask circuit 206 Image processing circuit 207 Image output unit 208 Control operation unit 209 Control circuit unit 210 CPU
211 RAM
212 ROM

Claims (5)

A document placement section for placing a document;
An openable / closable cover for covering the document placement portion;
An image reading unit that reads an image of the document placed on the document placement unit,
A document end detection memory that reads an image of a document placed on the document placing portion with the cover open by the image reading portion, and detects and stores a document end based on the brightness and saturation difference in the read image. Means,
An image of a document placed on the document placement unit with the cover open is read by the image reading unit, and based on brightness and saturation differences in a document region defined by the document edge in the read image. An image reading apparatus comprising: control means for detecting a punch hole and erasing the punch hole.   Punch hole position storage means for previously storing position information of punch holes that can be formed in the document area is further provided, and the control means detects the punch holes from within a predetermined area that matches the position information of the punch holes. The image reading apparatus according to claim 1, wherein:   The image reading apparatus according to claim 2, wherein the punch hole position information is information on a region extending from the document edge to a predetermined range.   The image reading apparatus according to claim 2, wherein the punch hole erasing process is performed within a predetermined range including the detected punch hole.   An image forming apparatus comprising the image reading apparatus according to claim 1.

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