JP4924443B2 - Image reading apparatus, image forming apparatus, image reading apparatus control method, and image reading apparatus control program - Google Patents

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program, and in particular, an image including a reading unit capable of reading the front and back surfaces of a double-sided document. The present invention relates to a reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program.

  Some electrophotographic image forming apparatuses (MFP (Multi Function Peripheral), facsimile machines, copiers, and the like) include a reading unit that can read the front and back sides of a double-sided document.

Patent Document 1 below discloses an image reading apparatus capable of selecting a plurality of modes in order to enable reading with no difference in image quality between the front and back sides.
JP 2007-82033 A

  In the conventional technique, the same image mode (reading image quality) is set on the front surface and the back surface of the document at the time of reading. Depending on the two-sided document, there may be a difference in glossiness between the front and back sides, but the conventional technology has a problem that an appropriate image mode cannot be set for the front and back sides of such a document. It was.

  Also, like a picture-story show, there are originals with pictures on the front and letters on the back. When the same image mode is set for the front side and the back side of such a document, the image desired by the user may not be obtained.

  In other words, in the conventional technology, when the user wants to read a document with different image quality and content between the front and back, or when the user wants to set a document mode (character mode, photo mode, figure mode, etc.) different between the front and back, There was a problem that could not be dealt with.

  The present invention has been made to solve such problems, and an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image capable of setting an appropriate image quality on the front and back surfaces. It is an object to provide a control program for a reader.

In order to achieve the above object, according to one aspect of the present invention, an image reading apparatus reads a front side and a back side of a double-sided document and creates image data, and the image quality differs between the front side and the back side. A setting means that can be set, an operation unit that allows a user to set different image quality combinations for the front and back sides, and a combination of image quality for the front and back sides, corresponding to the paper type of the document. Storage means, and the setting means switches the image quality of the image data created by the reading unit to the front and back image quality set by the operation unit, and corresponds to the paper type of the document stored in the storage means Depending on the combination of the front and back image quality, different image quality is set for the front and back surfaces. The paper type of a double-sided document is based on information including the amount of reflected light on each side or the background color on each side. Characterized by the type of paper specified To.

  Preferably, the image forming apparatus further includes an implementation unit for preventing show-through when the reading unit reads both sides of the document.

  Preferably, the implementation means performs a show-through prevention process for an area where the density difference between the images on the front and back sides of the document exceeds a predetermined value.

Preferably, when the image read with the image quality to be set on the front side and the back side of the document is affected by the image on the opposite side, the execution unit prohibits the setting and performs processing related to the change of the setting content. do, or urge a change of settings.

  Preferably, the change in the setting contents is a paper type change, or a change in one-sided copy, Nin1, weekly magazine binding, or other output method.

  Preferably, the implementation unit determines whether the image to be read is affected by the image on the opposite surface based on at least one of the image density, hue, and color balance on the front surface and the back surface of the document. .

  Preferably, the image forming apparatus further includes display means for displaying how to place the document based on the setting.

  Preferably, the image forming apparatus further includes a document type discriminating unit that discriminates a document type based on images of the front surface and the back surface of the document read by the reading unit, and the setting unit follows the determination result in the document type determining unit. Set different image quality on the front and back sides.

  Preferably, the image forming apparatus further includes a manuscript paper type discriminating unit that discriminates a paper type of the manuscript based on images of the front surface and the back surface of the manuscript read by the image reading unit, and the setting unit includes the manuscript paper type discriminating unit. According to the determination result in, different image quality is set for the front surface and the back surface.

  Preferably, the image forming apparatus further includes a character identification unit that identifies a character from an image read by the reading unit, and a storage unit that stores the character identified by the character identification unit as character identification information.

  Preferably, the image forming apparatus prohibits the function of the character identification unit when the setting unit sets the photo mode as the image quality.

  Preferably, the image forming apparatus prohibits the setting unit from setting a predetermined density when both the front and back surfaces of the image read by the reading unit are character portions.

  Preferably, the image forming apparatus prohibits setting of hue or color balance when color characters are identified on the front and back surfaces of the image read by the reading unit.

  According to another aspect of the present invention, an image forming apparatus can form an image on both sides of a sheet based on any of the image reading apparatuses described above and image data created by a reading unit. A forming part.

According to still another aspect of the present invention, the user can set a combination of image quality different between the reading unit capable of reading the front side and the back side of the double-sided document and creating image data and the front side and the back side. The control method of the image reading apparatus including the operation unit and the storage unit that stores the combination of the image quality of the front surface and the back surface corresponding to the paper type of the document is set to set different image quality on the front surface and the back surface. And a switching step for switching the image quality of the image data created by the reading unit to the image quality of the front surface and the back surface set by the operation unit, and the setting step sets the paper type of the document stored in the storage unit This is a step to set different image quality for the front and back sides according to the combination of the corresponding front and back image quality. The paper type of the double-sided document is information that includes the amount of reflected light on each side or the background color on each side. Paper type identified based on There, characterized in that.
Preferably, the control method of the image reading apparatus further includes a show-through prevention step for preventing show-through when the reading unit reads both sides of the document, and the show-through prevention step is set on the front side and the back side of the document. If the image read in the image quality is affected by the image on the opposite side, the setting is prohibited, the processing related to the change of the setting content is performed, or the change of the setting content is urged. Features.

According to still another aspect of the present invention, the user can set a combination of image quality different between the reading unit capable of reading the front side and the back side of the double-sided document and creating image data and the front side and the back side. A control program for an image reading apparatus including an operation unit and a storage unit that stores a combination of image quality on the front and back sides corresponding to the paper type of the document is set to set different image quality on the front and back sides. And a step of switching the image quality of the image data created by the reading unit to the image quality of the front and back surfaces set by the operation unit . This is a step to set different image quality for the front and back according to the combination of the image quality of the front and back corresponding to the paper type. Information to include A paper type specified based, characterized in that.
Preferably, the control program of the image reading apparatus causes the computer to further execute a show-through prevention step for preventing show-through when the reading unit reads both sides of the document. When an image scanned with the image quality to be set in step S is affected by the image on the opposite side, the setting is prohibited, the processing related to the change of the setting content is performed, or the change of the setting content is urged. It is characterized by being.

  According to these inventions, it is possible to provide an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program capable of setting appropriate image quality on the front and back surfaces. .

  [First Embodiment]

  The image reading apparatus according to the first embodiment of the present invention will be described below.

  The image reading apparatus can be mounted on the image forming apparatus or can operate alone as a scanner.

  An image forming apparatus including an image reading apparatus includes a reading unit capable of reading both sides of a document at the same time, an operation unit capable of setting different image quality for the front and back sides of the document, and the front and back sides of the document. And an image processing unit that performs image processing according to different image quality, and an image forming unit that forms an image based on data set by the image processing unit.

  With this configuration, it is possible to set an appropriate image quality for the front and back images of the double-sided document in the image reading apparatus. Further, it is possible to cope with a case where the user demands different image quality for the front and back sides.

  FIG. 1 is a diagram illustrating an overview of an image forming apparatus according to the first embodiment.

  Referring to the figure, the image forming apparatus includes an image reading unit 1 including an automatic document feeder, an image processing unit 3, an image forming unit 5, a paper feeding unit 7, and a paper discharging unit 9.

  When the image forming apparatus is used as a printer, the image reading unit 1 reads both sides of the document simultaneously. The image processing unit 3 can set different image quality for each of the front and back images. Image processing is performed according to the image quality. The image forming unit 5 prints the processed image on the paper sent from the paper supply unit 7. The printed paper is discharged from the paper discharge unit 9.

  FIG. 2 is a diagram illustrating a configuration of the image reading unit 1 including the automatic document feeder.

  The image reading unit 1 including the automatic document feeder is roughly composed of a reading unit 103 and a document conveying device 101.

  The reading unit 103 includes a first reading position 202, a platen glass 205, an exposure device 206, mirrors 207, 208, and 209, a lens 211, and a CCD (Charge Coupled Device) 213.

  The document feeder 101 includes a paper feed tray 201, a paper feed roller 220, a separation roller 221, a transport roller 222, a pre-reading roller 223, a post-reading roller 224, a second reading position 203, a CIS (Contact). Image Sensor) 320, reverse roller 225, paper discharge roller 226, and paper discharge tray 204.

  The documents 200 stacked on the sheet feeding tray 201 of the document conveying apparatus 101 are fed by the sheet feeding roller 220, separated one by one by the separation roller 221, and the first reading position by the conveying roller 222 and the pre-reading roller 223. It is conveyed to 202. The reading unit 103 exposes the document 200 passing through the first reading position 202 with the exposure device 206, and generates image data as RGB data from the CCD 213 through the platen glass 205, mirrors 207, 208, and 209 and the lens 211. The document 200 that has passed the first reading position 202 is conveyed to the second reading position 203. The document 200 is read by the CIS 320 at the second reading position 203, and image data is generated. The surface on which the document 200 is read at the second reading position 203 is the surface opposite to the surface read at the first reading position 202. After passing through the second reading position 203, the document 200 is conveyed by the reverse roller 225 and the paper discharge roller 226 and is discharged to the discharge tray 204. By reading the images in this way, the images on both sides can be read at the same time with a single sheet passing.

  Here, at the first reading position 202, the document 200 is guided by the conveyance guide member so as to be conveyed in a non-contact manner with the platen glass. In addition, the post-reading roller 224 is slightly faster than the pre-reading roller 223 so that the document 200 is pulled. Thereby, contact between the platen glass 205 and the original 200 due to the slack of the original 200 is prevented. If there are foreign substances such as paper dust or adhesive on the platen glass 205 at the reading position, they remain at the reading position, and thus appear as color streak noise in the conveyance direction of the document 200. The foreign matter is supplied onto the platen glass mainly by contact between the document 200 and the platen glass. As described above, the original 200 is not brought into contact with the platen glass, thereby preventing the supply of these foreign substances.

  Although not shown, the paper feed tray 201 of the document conveying apparatus 101 is provided with a guide member for preventing tilting during paper feeding. The size of the document on the paper feed tray 201 can be determined by a combination of a position detection sensor connected to the guide member and a plurality of document detection members provided in the conveyance direction of the paper feed tray 201.

  Further, in the document conveying apparatus 101, without using the CIS 320, it is possible to invert the document after one-side reading and pass the first reading position 202 again, and the CCD 213 can also read the back side of the document.

  FIG. 3 is a diagram illustrating a control unit included in the image forming apparatus of FIG.

  The control unit 300 stores data, an image reading unit 1 that reads a document, an image processing unit 5 that performs processing such as compressing and expanding image data, an image forming unit 303 that prints image data on paper, and the like. Storage unit 305 that performs processing, image output unit 307 that controls printing processing of image data, facsimile control unit 309 that transmits image data through a communication line, and a network that controls connection between the MFP and the communication line and other devices Data can be rewritten with a connection unit 311, a CPU (central processing unit) 313 that controls the entire system, a ROM 315 that stores read-only data that cannot be rewritten, and a RAM 317 that temporarily stores data. Nonvolatile memory 319 and HDD (Hard Disk Drive) 321, and system A display unit 323 for displaying the information and a panel operation unit 325 capable of giving processing instructions to the system.

  The CPU 313 includes a determination unit 313a, a deletion unit 313b, a control unit 313c, and a notification unit 313d, and is in charge of each process of the CPU.

  The facsimile control unit 309 includes a receiving unit 309a.

  Further, the panel operation unit 325 includes a condition setting key 325a that can set different image quality (reading mode) for each of the front and back sides of the document.

  With the CPU 313 as the center, each module is controlled based on communication and control signals. The CPU 313 includes an image reading unit 1, an image processing unit 301, an image forming unit 303, a storage unit 305, an image output unit 307, a facsimile control unit 309, a network connection unit 311, a ROM 315, a RAM 317, a nonvolatile memory 319, an HDD 321, and a display unit 323. And the control part 300 whole is controlled by implementing communication or signal transmission / reception with the panel operation part 325.

  The image data read by the image reading unit 1 is temporarily stored in a file memory area secured on the RAM 317.

  FIG. 4 is a block diagram illustrating a functional configuration of the image forming apparatus.

  The image forming apparatus includes an image reading unit 1, an operation unit 401 that can set the read image quality of the front and back sides of the document, and image processing corresponding to the set contents for the image data of the front and back sides. And an image forming unit 405 that outputs the processed image data.

  The image forming apparatus also includes a storage unit 305 that stores image quality to be set for the front and back sides of the document according to the document type or the paper type.

  Further, the image forming apparatus includes a paper type determination unit 403a that determines the paper type of the document from the read image data, a transmitted light amount detection unit 403b that detects the amount of light that passes through the document, and a content in the document based on the read image data. A paper type / original determination unit 403 is provided that includes an area determination unit 403c that determines each area and an original type determination unit 403d that determines the type of an original from information determined by the area determination unit 403c.

  FIG. 5 is a diagram illustrating image quality settings corresponding to the document type stored in the storage unit 305 and image quality settings corresponding to the paper type.

  As shown on the left of FIG. 5, the image quality set for each document type is stored. That is, if the document is a text / photo document, the setting of document 1 is adopted, if the document is a text document, the setting of document 2 is adopted, and if the document is a photo document, the setting of document 3 is adopted. Here, the setting can be made independently for the front and back of the document. That is, if the front is a text-based document and the back is a photo-based document, the document 2 is set for the front and the document 3 is set for the back.

  As shown on the right side of FIG. 5, the image quality set for each paper type of the document is stored. That is, if the original is thin paper 1, the setting of paper 1 is adopted, if the original is thin paper 2, the setting of paper 2 is adopted, and if the original is thick paper 1, the setting of paper 3 is adopted. Again, the image quality can be set independently for the front and back of the document. In other words, if the front is glossy paper and the back is plain paper, the glossy paper is set for the front and the plain paper is set for the back.

  The document type can be arbitrarily registered by the user in addition to the previously registered text / photo, text, and photo. Similarly, the user can arbitrarily register the paper type other than the thin paper and the thick paper registered in advance.

  FIG. 6 is a diagram showing a screen for setting the front and back image quality of the document displayed on the liquid crystal touch panel of the panel operation unit 325.

  Here, the user can select either of the “front” key and the “back” key and set the image mode and the image density of the surface. That is, an image mode (in this case, a text original, a text / photo original, a photo original, or a thin text original) can be set for each of the front and back sides.

  Further, the reading density of the image (and the printing density at the time of copying) can be set for each of the front side and the back side.

  When storing an image of a CCD sensor or CIS in a memory or when outputting (printing or the like), image data is converted in accordance with a set image quality. For example, when conversion from RGB to another color space is performed, data conversion is performed based on the set image quality.

  FIG. 7 is a diagram showing a message display screen for explaining how to place a document displayed on the liquid crystal touch panel after setting the image quality of both sides.

  When different image quality is set for the back and front, the document must be placed correctly on the front and back. Therefore, a screen as shown in FIG. 7 is displayed before scanning, and the user is explained how to place the document.

  The screen of FIG. 7 is a display screen when at least one image quality setting is performed on the front surface and the back surface on the operation unit, and prompts the user to set the front surface upward on the document placement member according to the document setting. A message is displayed. Here, an example of a message indicating that the front side is set upward is shown, but a message indicating that the back side is set upward is displayed according to the configuration of the document conveying apparatus.

  With such a display, for example, when processing a manuscript with glossy paper on the front side and plain paper on the back side, the reverse side is prevented from being reversed by mistake.

  FIG. 8 is a flowchart showing an operation during copying of the image forming apparatus.

  In step S101, it is determined whether the copy is a double-sided copy (a copy in which a double-sided original image is read and copied on both sides of the paper). If YES, the document is pre-scanned in step S103, and the show-through prevention adjustment (FIG. 9) is performed. Thereafter, double-sided scanning of the image from the original is performed in step S105, image forming processing is performed, and the image is output in step S107.

  In the case of single-sided copying (NO in S101), image formation processing and image output are performed without performing show-through prevention adjustment.

  The show-through means that the scanned image is output (printed, etc.) and the image on the back side of the original is visible when the output image is viewed (or the show-through occurs when the printed material is further copied). Occurs). The show-through prevention adjustment is a process for preventing such reflection.

  Note that, as described above, the show-through prevention adjustment may be performed on the image obtained by the preliminary scan, or the scan performed by the show-through prevention adjustment may be the main scan. That is, in this case, scanning is not performed in step S105, and image formation is performed based on the image obtained by the show-through prevention adjustment.

  FIG. 9 is a flowchart showing the contents of the show-through prevention adjustment process (S103) of FIG.

  In order to prevent the show-through, the document is scanned in step S201, and the density difference between the image data on the front surface and the back surface is calculated. Here, the difference between the average density of the image data on the front surface and the average density of the image data on the back surface may be calculated, or area discrimination is performed within one page, and the difference in average density between the front and back areas. May be calculated. For example, the average density difference between the front and back character areas may be calculated.

  In step S203, it is determined whether the calculated density difference is larger than a predetermined value a. If YES, a show-through prevention process is performed in step S205.

  The show-through prevention process is a process of invalidating one of the densities set for the front and back, or invalidating both. For example, even if the image quality setting is set to a darker side, the image is reset to the default state (change in image quality is prohibited). This prevents the image on the side opposite to the reading side from appearing in the read image.

  Note that as the show-through prevention process, a process of reducing the density set for the front and back sides to such an extent that the opposite surface is not shown may be executed.

  Further, the show-through prevention processing may be performed only on an area where show-through may occur. For example, an area where characters are present at the same position on the paper on the front and back.

  [Second Embodiment]

  Since the hardware configuration of the image forming apparatus in the second embodiment of the present invention is the same as that in the first embodiment, description thereof will not be repeated.

  The image forming apparatus in the present embodiment can also set different image quality on the front surface and the back surface. The combination of image quality settings on the front and back surfaces is prohibited when the normal image quality is not achieved.

  FIG. 10 is a flowchart showing image setting content combination prohibition (combination prohibition) processing executed by the image forming apparatus according to the second embodiment.

  In step S301, the image quality setting contents (image quality change contents) for the front side and the back side in step S303 are acquired. In step S305, it is determined whether the image quality set for each of the front and back is a combination that affects the other.

  If the combination has an influence (YES in S305), it is determined in step S307 whether the combination is prohibited according to the setting.

  If “YES” in the step S307, the composition prohibition is performed in a step S309. If “NO” in the step S307, a display prompting the user to change the image quality setting is performed in a step S311.

  If “NO” in the step S305, the process of FIG. 10 is ended, and the document reading process is performed with the set image quality.

  FIG. 11 is a view showing a message screen indicating the prohibited combination displayed in step S309 of FIG.

  When combination prohibition is executed, priority may be given to the setting of the surface (front surface or back surface) set earlier, or priority may be given to either the front or back regardless of the setting order. Further, both the front and back settings may be invalidated.

  FIG. 12 is a diagram showing a message screen for prompting the setting change displayed in step S311 of FIG.

  On this screen, it is displayed to the user that the image quality may affect the other surface. The content prompting the change of the paper type or the change from the double-sided copy to another output form is displayed.

  FIG. 13 is a diagram showing a screen for setting message switching when a combination prohibition occurs.

  Here, the user can switch between displaying the message shown in FIG. 11 or the message shown in FIG. 12 as a message for changing the image quality. When the combination prohibition occurs, the message of FIG. 11 or FIG. 12 is displayed according to this setting.

  [Third Embodiment]

  Since the hardware configuration of the image reading apparatus in the third embodiment of the present invention is the same as that in the first embodiment, the description thereof will not be repeated.

  The image reading apparatus according to the present embodiment can also set different image quality on the front surface and the back surface. The image quality settings for the front and back surfaces can be switched according to the type of paper of the document and the types of front and back regions of the document.

  FIG. 14 is a flowchart illustrating image quality switching processing based on the paper type executed by the image reading apparatus according to the third embodiment.

  In step S401, an image of a part (edge) of the document is read. In step S403, the transmitted light amount of the document is measured by the transmitted light amount detection unit 403b. Based on this, the thickness of the original paper is measured in step S405.

  In step S407, the image of the read original is analyzed. In step S409, based on the image analysis, the paper type is determined from the combination of the color / density matching results of the background portions on both sides of the document, the transmitted light amount, and the paper thickness.

  In step S411, the image quality set for the front and back is switched based on the paper type based on the table on the right side of FIG.

  FIG. 15 is a diagram showing a paper type determination table used in step S409 of FIG.

  Based on the transmitted light amount, the paper thickness, and the combination of the base color (front and back), the closest one is selected from a plurality of paper types.

  In addition to paper types such as thin paper and thick paper registered in advance, the user can arbitrarily register the corresponding paper type by a combination of the transmitted light amount, the paper thickness, and the background color. In this embodiment, the paper type is determined based on the transmitted light amount, the paper thickness, and the background color. However, the paper type may be determined based on information such as a paper feed torque and a reflected light amount.

  Thereby, appropriate image quality can be set on the back and front according to the paper type.

  FIG. 16 is a flowchart illustrating image quality switching processing based on the document type executed by the image reading apparatus according to the third embodiment.

  In step S451, the front and back images of the document are read. In step S453, the area determination unit 403c performs area determination on both the front and back images of the document. This detects a character area, a photographic area, a graphic area, and the like in an image.

  In step S455, the document type is determined based on the result of the area discrimination. In step S457, the setting of the image quality of the front side and the back side is switched based on the determined document type based on the left table of FIG.

  Here, the type of document registered in advance is identified, but the threshold value of each determination parameter for region determination is individually set so as to determine the type of document arbitrarily registered by the user. Also good.

  For area discrimination, generally known black character part, color character part, white spot part, black spot part, high frequency component and low frequency component are detected, and the area is judged according to their ratio It is also possible to use a method for determining the area, or to register a dedicated area determination method for identifying a special document.

  [Fourth Embodiment]

  The image reading apparatus according to the fourth embodiment of the present invention can also set different image quality on the front surface and the back surface. Based on the image quality settings on the front and back surfaces, the character identification function is enabled / disabled at the time of image reading.

  FIG. 17 is a block diagram illustrating an overall configuration of an image reading apparatus according to the fourth embodiment.

  The image reading apparatus stores a reading unit 1 that can simultaneously read both sides of a double-sided document, a character identifying unit 501 that identifies a character part from the read image, and stores the identified character data in accordance with the character position. A character information storage unit 503, an operation unit 325 for setting a level for determining a character part, designating a reading mode and a document mode, and an image processing unit 301 for performing image processing according to the set reading mode and document mode. And.

  The information stored in the character information storage unit 503 may be in a state where characters are generally encoded, or may be image data itself. Furthermore, regarding the character position, the front and back character portions may all have the coordinates of each character, or may be recognized as a character string and held as the character string coordinates.

  FIG. 18 is a flowchart illustrating a character identification function prohibiting process executed by the image reading apparatus according to the fourth embodiment.

  Referring to the drawing, in step S501, the original mode (set image quality) is acquired. If the front side is set to the photo mode in step S503, the back side character identification is prohibited in step S505.

  If it is determined in step S507 that the back side is a photo mode, the front side character identification is prohibited in step S509.

  The surface on which the photo is printed often has no background, and the image density is high. For this reason, if the back side of the character image is a photographic document, the character recognition performance deteriorates, and erroneous determination is likely to occur. For this reason, identification of characters is prohibited on the back side of the surface on which the photo mode is set.

  Here, it is decided whether or not to prohibit the character identification function on the opposite side according to the mode setting on one side, but the position of the opposite side of the area detected as the character part on one side is Only when it is detected that it is a photograph part, the character identification function of the character part may be prohibited.

  [Fifth Embodiment]

  Since the hardware configuration of the image reading apparatus in the fifth embodiment of the present invention is the same as that in the first embodiment, the description thereof will not be repeated.

  The image reading apparatus according to the present embodiment can also set different image quality on the front surface and the back surface. Whether or not to change the image quality setting is determined based on the positions of the character portions on the front and back surfaces. As a result, it is possible to prevent the influence of the back image being reflected in the character image.

  FIG. 19 is a flowchart illustrating a character part image quality change prohibiting process executed by the image reading apparatus according to the fifth embodiment.

  In step S601, images on both sides of the document are read, and in step S603 and S605, the front and back character portions are extracted. In step S607, the extracted character part is analyzed, and it is determined in step S609 whether all character parts have been checked.

  If all the character parts are not checked in step S609, it is determined in step S611 whether the positions of the front and back character parts are the same. If they are at the same position, it is determined in step S613 whether the character attribute of the character portion of the table is different from the character attribute of the reverse character portion. If YES, since the character on one side may affect the characters on the other side, such as show-through, change of image quality is prohibited in step S615.

  Here, the “character attribute” indicates a character type such as a black character, a color character, a white character, or a negative / positive character (reverse character).

  If NO in step S611 or S613, the process returns to step S607, and the analysis of the next and subsequent character parts is repeated until the analysis of all character parts is completed.

  If “YES” in the step S609, the process is ended, and the image quality change is not prohibited.

  FIG. 20 is a flowchart illustrating image quality change prohibition processing of the color character portion executed by the image reading apparatus according to the fifth embodiment.

  In step S701, images on both sides of the document are read, and in step S703 and S705, the color character portions on the front and back sides are extracted. In step S707, the extracted color character part is analyzed, and it is determined in step S709 whether all color character parts have been checked.

  If all the color character portions are not checked in step S709, it is determined in step S711 whether the positions of the front and back color character portions are the same. If they are at the same position, in step S713, whether the hues of the front and back color character portions are greater than or equal to a predetermined shift or whether the color balance is greater than or equal to a predetermined difference (whether the color balance is different between the front and back). judge.

  If “YES” in the step S713, the setting of the image quality is prohibited in a step S715 because the setting of the hue and the color balance of one surface may affect the image of the other surface.

  If NO in step S711 or S713, the process returns to step S707, and the analysis of the next and subsequent color character portions is repeated until the analysis of all the color character portions is completed.

  If “YES” in the step S709, the process is ended, and the image quality change is not prohibited.

  FIG. 21 is a flowchart illustrating a character portion image quality change prohibiting process executed by the image reading apparatus according to the fifth embodiment.

  In step S801, the images on both sides of the document are read, and in step S803 and S805, the front and back character portions and the photograph portion are extracted. In step S807, the extracted character part is analyzed, and it is determined in step S809 whether all the character parts have been checked.

  If all the character portions are not checked in step S809, it is determined in step S811 whether the position of the character portion on one side of the document is the same as the position of the photo portion on the other side. If they are at the same position, the image on one side of the image may affect the characters on the other side, such as show-through, so that the image quality change is prohibited in step S815.

  If “NO” in the step S811, the process returns to the step S807, and the analysis of the next and subsequent character parts is repeated until the analysis of all the character parts is completed.

  If “YES” in the step S809, the process is ended, and the image quality change is not prohibited.

  FIG. 22 is a flowchart illustrating character image quality change prohibition processing executed by the image reading apparatus according to the fifth embodiment.

  In step S901, images on both sides of the document are read, and in step S903 and S905, the front and back character portions are extracted. In step S907, the extracted character part is analyzed, and it is determined in step S909 whether all character parts have been checked.

  If all the character parts have not been checked in step S909, it is determined in step S911 whether the positions of the front and back character parts are the same. If they are at the same position, it is determined in step S913 whether the sum of the density of the front character part and the density of the back character part exceeds a predetermined value D. If YES, since the character on one side may affect the characters on the other side, such as show-through, change of image quality is prohibited in step S915.

  If NO in step S911 or S913, the process returns to step S907, and the analysis of the next and subsequent character parts is repeated until the analysis of all the character parts is completed.

  If “YES” in the step S909, the process is ended, and the image quality change is not prohibited.

  In step S913, the determination is made by comparing the sum of the density and the predetermined value D. However, if the difference in the density of the characters exceeds the predetermined difference D ', the determination may be YES.

  FIG. 23 is a diagram illustrating a specific example of processing executed by the image reading apparatus according to the fifth embodiment.

  Here, a state is shown in which characters “A”, “B”, “C”, and “D” are written on the surface of the document. The right direction of the document is the X direction, and the downward direction of the document is the Y direction.

  The character “A” is a black character with a white outline (reverse character). The letter “B” is a cyan color letter. The letter “C” is a normal black letter. The letter “D” is a high density black letter.

  On the back side of the document, characters “A”, “I”, “E”, and a photo are shown.

  The character “a” is a normal black character. The character “I” is a red color character. The letters “e” are low density black letters. The part of the photograph shows a photograph area.

  “A” is located behind “A”. That is, on the front and back, the character part “A” and the character part “A” are in the same position. Similarly, “I” is located behind “B”. The photo section is located behind “C”. “E” is located behind “D”.

  If such characters exist at the same position on the front and back, image quality setting is prohibited.

  That is, in the combination of “A” and “A”, according to the flowchart of FIG. 19, it is determined in step S611 that there is a character at the same position on the front and back (YES), and in step S613, the attribute of the character portion of the table ( It is determined that the white character) is different from the attribute (normal character) of the back character part (YES).

  When “A” is inverted (hatched) between “A” and “A” that are in a relationship of front and back, show-through may occur on the other “A”. On the other hand, the character “A” on the back surface may also affect “A”, which is a white character portion. In this case, the setting of image quality is prohibited to prevent the image from becoming too dark.

  In the combination of “B” and “I”, it is determined in step S711 that there is a color character at the same position on the front and back (YES) according to the flowchart of FIG. 20, and the hue of the character portion of the front is determined in step S713. It is determined that the color balance is different (YES) between (blue) and the hue (red) of the character portion on the back.

  In “B” and “I” that are in a front-back relationship, if the colors of both are too different, each may be show-through on the other side. If the show-through occurs, the color of the characters will be affected. Therefore, the setting of the image quality is prohibited to prevent the image from becoming too dark.

  For the combination of “C” and the photo part, it is determined in step S811 that there is a character and a photo at the same position on the front and back (YES) according to the flowchart of FIG.

  In “C” and the photo part which are in a relationship of front and back, there is a possibility that the photo part may show through to the characters on the other side. In this case, the setting of image quality is prohibited to prevent the image from becoming too dark.

  In the combination of “D” and “E”, it is determined in step S911 that there is a character at the same position on the front and back (YES) according to the flowchart of FIG. 22, and the density of the character portion of the table is determined in step S913. It is determined that the sum (or density difference) is large (YES).

  In “D” and “e” which are in a relationship of front and back, there is a possibility that the high-density character “D” may be seen through to the low-density character “e”. In this case, the setting of image quality is prohibited to prevent the image from becoming too dark. In addition, if the setting is made to lower the density of the character portion of “e”, “e” is not captured, and the setting of image quality is prohibited.

  Instead of prohibiting setting (changing) of image quality, setting of image quality exceeding a predetermined density may be prohibited.

  In the processing of FIG. 20, when color characters are identified on the front and back surfaces, setting of image quality related to hue or color balance is prohibited instead of prohibiting setting (changing) of image quality. May be.

  [Sixth Embodiment]

  Since the hardware configuration of the image forming apparatus according to the sixth embodiment of the present invention is the same as that of the first embodiment, description thereof will not be repeated here.

  The image forming apparatus in the present embodiment can also set different image quality on the front surface and the back surface. As a method for preventing the influence of the back image appearing on the image on one side based on the positions of the character portions on the front surface and the back surface, the image reading apparatus in the present embodiment has an output form. change.

  FIG. 24 is a diagram for explaining an output form change executed by the image forming apparatus according to the sixth embodiment.

  When processing a double-sided document, it is usually printed as a double-sided output.

  The image reading apparatus in the sixth embodiment performs the same processing as in the first to fifth embodiments,

  (1) When the density difference between the back side and the front side becomes large and the show-through prevention processing is performed (S205 in FIG. 9),

  (2) When image quality setting is prohibited on the back and front (S309 in FIG. 10), or

  (3) When the image at the same position on the back side affects the characters, and the image quality change is prohibited (S615 in FIG. 19, S715 in FIG. 20, S815 in FIG. 21, S915 in FIG. 22),

  When this occurs, processing for shifting the positions of the front and back images is performed instead of these processing.

  That is, when the image quality setting affects the image quality on the opposite side in duplex copying, the output is changed to one-sided output without the opposite side, the 2in1 (other, Nin1) output is changed, or the front and back positional relationship Or change the output of the weekly magazine that changes. As a result, the image quality desired by the user can be set, and adverse effects due to the image quality setting can be prevented.

  Further, when changing the output form, the user may select a desired one, or the output may be performed in the default output form.

  In step S309 in FIG. 10, the prohibition may be performed, and in step S311, processing for prompting the user to change the output form may be performed as shown in FIG.

  Here, the output form (output method) is changed. However, when the image quality setting affects the image quality of the opposite side in duplex copying, the user is prompted to change the paper (original paper or copy paper). It may be.

  [Effects of the embodiment]

  As described above, the image reading apparatus has an operation unit capable of setting the image quality separately for the front and back sides, and the image of the read double-sided document according to the front and back image quality designated by the operation unit. Is printed, and an image forming unit that performs image processing is provided.

  In the operation unit, it is preferable that the document mode, the image quality mode (color balance, sharpness, contrast, brightness, hue, density, etc.) and the color mode can be switched at least individually between the front and back of the document.

  As a result, as required by the user, the read data can be acquired with different image quality for the front and back sides. In addition, it is possible to output an image with the data read as such.

  In addition, it is possible to prevent the setting contents from affecting the image quality, and an image unintended by the user is prevented from being output.

  [Others]

  Note that the paper type (thickness, etc.) of the document affects the show-through. If there is a possibility of show-through, it may be displayed to the user that show-through may occur with the current paper type. Such display may be performed by determining the paper type of the document.

  The processing in the above-described embodiment may be performed by software or by using a hardware circuit.

  In addition, a program for executing the processing in the above-described embodiment can be provided, and the program is recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, and a memory card and provided to the user. You may decide to do it. The program may be downloaded to the apparatus via a communication line such as the Internet.

  In addition, it should be thought that the said embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a diagram illustrating an overview of an image forming apparatus according to a first embodiment. 1 is a diagram illustrating a configuration of an image reading unit 1 including an automatic document feeder. It is a figure which shows the control part contained in the image forming apparatus of FIG. 2 is a block diagram illustrating a functional configuration of the image forming apparatus. FIG. FIG. 6 is a diagram illustrating image quality settings corresponding to document types stored in a storage unit 305 and image quality settings corresponding to paper types. FIG. 10 is a diagram showing a screen for setting the front and back image quality of a document displayed on the liquid crystal touch panel of the panel operation unit 325. It is a figure which shows the message display screen explaining how to put the document displayed on a liquid crystal touch panel after setting the image quality of both sides. 6 is a flowchart illustrating an operation at the time of copying of the image forming apparatus. It is a flowchart which shows the content of the show-through prevention adjustment process (S103) of FIG. 10 is a flowchart illustrating combination prohibition (combination prohibition) processing of image setting contents executed by the image reading apparatus according to the second embodiment. It is a figure which shows the message screen which shows the combination prohibition displayed by step S309 of FIG. FIG. 11 is a diagram showing a message screen for prompting a setting change displayed in step S311 of FIG. 10. It is a figure which shows the screen for setting the switch of the message at the time of a combination prohibition occurrence. 14 is a flowchart illustrating image quality switching processing based on a paper type executed by an image reading apparatus according to a third embodiment. It is a figure which shows the paper type judgment table used by FIG.14 S409. 12 is a flowchart illustrating image quality switching processing based on a document type executed by an image reading apparatus according to a third embodiment. It is a block diagram which shows the whole structure of the image reading apparatus in 4th Embodiment. 14 is a flowchart illustrating a character identification function prohibiting process executed by an image reading apparatus according to a fourth embodiment. 14 is a flowchart illustrating character image quality change prohibition processing executed by an image reading apparatus according to a fifth embodiment. 16 is a flowchart illustrating image quality change prohibition processing for a color character portion, which is executed by an image reading apparatus according to a fifth embodiment. 14 is a flowchart illustrating character image quality change prohibition processing executed by an image reading apparatus according to a fifth embodiment. 14 is a flowchart illustrating character image quality change prohibition processing executed by an image reading apparatus according to a fifth embodiment. FIG. 10 is a diagram illustrating a specific example of processing executed by an image reading apparatus according to a fifth embodiment. It is a figure for demonstrating the output form change which the image reading apparatus in 6th Embodiment performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reading part 3 Image processing part 5 Image forming part 7 Paper feed part 9 Paper discharge part 101 Document conveying apparatus 103 Reading unit 200 Document 201 Paper feed tray 204 Paper discharge tray 205 Platen glass 206 Exposure apparatus 220 Paper feed roller 226 Paper discharge roller 300 Control Unit 301 Image Processing Unit 303 Image Forming Unit 305 Storage Unit 307 Image Output Unit 309 Facsimile Control Unit 323 Display Unit 325 Panel Operation Unit 325a Condition Setting Key 401 Operation Unit 403 Paper Type / Document Determination Unit 403a Paper Type Determination Unit 403b Transmission Light amount detection unit 403c Area determination unit 403d Document type determination unit 405 Image forming unit 501 Character identification unit 503 Character information storage unit

Claims (18)

A reading unit capable of reading the front and back sides of a double-sided document to create image data;
Setting means capable of setting different image quality on the front surface and the back surface;
An operation unit that allows a user to set a combination of different image quality on the front surface and the back surface;
Quality combination of the surface and the back surface, comprising storage means for storing in response to the paper type of the original, and
The setting means,
The image quality of the image data created by the reading unit is switched to the image quality of the front surface and the back surface set by the operation unit,
According to the combination of image quality of the front and back surfaces corresponding to the paper type of the document stored in the storage means, different image quality is set for the front and back surfaces ,
2. The image reading apparatus according to claim 1, wherein the paper type of the double-sided document is a paper type specified based on information including a reflected light amount of each surface or a background color of each surface. The image reading apparatus according to claim 1, further comprising an implementation unit configured to prevent show-through when the reading unit reads both sides of the document. The image reading apparatus according to claim 2 , wherein the execution unit performs a show-through prevention process on an area where the density difference between the images on both the front surface and the back surface of the document exceeds a predetermined value. The implementation means performs processing related to changing the setting contents , forbidden when an image read with the image quality to be set on the front and back sides of the document is affected by the image on the opposite side. or encourage changes the settings, the image reading apparatus according to claim 2. The image reading apparatus according to claim 4 , wherein the change in the setting content is a change in paper type, or a change in one-sided copy, Nin1, weekly magazine binding, or other output method. The implementation means determines whether the image to be read is affected by the image on the opposite surface based on at least one of the image density, hue, and color balance on the front surface and the back surface of the document. The image reading apparatus according to claim 4 or 5 . Based on the setting, further comprising a display means for displaying the way of placing the document, the image reading apparatus according to any one of claims 1 to 6. A document type discriminating unit for discriminating a document type based on images of the front and back sides of the document read by the reading unit;
The setting means, in accordance with the determination result in the document-type identification unit, sets a different image quality and the surface and the back surface, the image reading apparatus according to any one of claims 1 to 7. A document paper type discriminating unit that discriminates the paper type of the document based on the images of the front and back sides of the document read by the image reading unit;
The setting means, in accordance with the determination result in the original paper type determining unit sets a different image quality and the back surface and the surface, the image reading apparatus according to any one of claims 1 to 8. A character identification unit for identifying a character from an image read by the reading unit;
The characters identified by the character recognition unit further comprising a storage unit that stores as character identification information, the image reading apparatus according to any one of claims 1 to 9. In the setting unit, when the photographic mode is set as the image quality, it prohibits the functions of the character recognition unit, an image reading apparatus according to claim 1 0. If the front and back of the image read by the reading unit are both character unit, prohibits the setting exceeding a predetermined concentration by the setting means is performed, an image according to claim 1 0 or 1 1 Reader. Wherein if the color characters between the front surface and the back surface of the image read by the reading unit is identified, to prohibit the setting of the hue or color balance, image reading apparatus according to claim 1 0 1 2. An image reading apparatus according to any one of claims 1 to 1 4,
An image forming apparatus comprising: an image forming unit capable of forming images on both sides of a sheet based on image data created by the reading unit. A reading unit capable of reading the front and back sides of a double-sided document to create image data ;
An operation unit that allows a user to set a combination of different image quality on the front surface and the back surface;
Quality combination of the surface and the back surface, Ri control method der of the image reading apparatus having storage means for storing in response to the paper type of the original, and
A setting step for setting different image quality on the front surface and the back surface ;
A switching step of switching the image quality of the image data created by the reading unit to the image quality of the front surface and the back surface set by the operation unit ,
The setting step includes
Setting different image quality on the front surface and the back surface according to a combination of image quality on the front surface and back surface corresponding to the paper type of the document stored in the storage means;
The method of controlling an image reading apparatus, wherein the paper type of the double-sided document is a paper type specified based on information including a reflected light amount of each surface or a background color of each surface .   When the reading unit reads both sides of the document, it further includes a show-through preventing step for preventing show-through,
  The show-through prevention step is a process for prohibiting setting when an image read with image quality to be set on the front and back sides of the document is affected by an image on the opposite side, and changing the setting contents 16. The method of controlling an image reading apparatus according to claim 15, characterized in that the step is a step of performing a change or prompting a change of setting contents. A reading unit capable of reading the front and back sides of a double-sided document to create image data ;
An operation unit that allows a user to set a combination of different image quality on the front surface and the back surface;
A storage unit that stores a combination of image quality of the front and back surfaces in correspondence with the paper type of the document ;
A setting step for setting different image quality on the front surface and the back surface ;
A switching step of switching the image quality of the image data created by the reading unit to the image quality of the front and back surfaces set by the operation unit ;
The setting step includes
Setting different image quality on the front surface and the back surface according to a combination of image quality on the front surface and back surface corresponding to the paper type of the document stored in the storage means;
The control program for an image reading apparatus, wherein the paper type of the double-sided document is a paper type specified based on information including a reflected light amount of each surface or a background color of each surface .   When the reading unit reads both sides of the document, the computer further executes a show-through prevention step for preventing show-through,
  The show-through prevention step is a process for prohibiting setting when an image read with image quality to be set on the front and back sides of the document is affected by an image on the opposite side, and changing the setting contents The control program for an image reading apparatus according to claim 17, wherein the control program is a step for performing or prompting a change in setting contents.

Images