JP2010136054A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader which extracts only information related to an achromatic paint part from each original on the basis of a difference from a reproduction form original by reproducing a form original in which the achromatic paint part is erased from an original including the part drawn in achromatic paint that becomes achromatic when heated. <P>SOLUTION: A control part 11 stores first image information obtained by reading a first original including the part drawn in the achromatic paint by a reading part 12 in an image storing part 14, then heats the first original to be achromatic by a heater 25, and subsequently extracts and stores information on a difference between the first image information and the second image information after rereading the first information by the reading part and storing the second image information. Further, after that, the control part 11 controls the execution of a reading and extraction operation that reads the second original in which drawn contents except the part drawn in the achromatic paint are the same as those of the first original by the reading part to obtain third image information, and extracts and stores difference information between the third image information and the second image information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that optically reads an original, and more particularly to an image reading apparatus that reads an original including a portion drawn with a paint that becomes colorless when heated.

  2. Description of the Related Art Conventionally, from the viewpoint of effective use / reuse of paper resources, there is a writing instrument using ink that becomes colorless when heated to a high temperature such as 60 ° C. or higher. In addition, there is an ink jet printer that includes a recording unit that uses ink that becomes colorless when heated, and a heating unit that is disposed in front of the recording unit and that decolorizes ink (see, for example, Patent Document 1).

JP 2001-302954 A

  In the case where personal information entered on a questionnaire sheet or the like is read and digitized by a scanner and stored and managed in a database or the like, storing the entire image obtained by reading each questionnaire sheet increases the storage capacity. For this reason, an image of an unfilled questionnaire sheet is compared with an image of a completed questionnaire sheet, and the difference (portion entered by the respondent) is extracted, and only the extracted difference information is stored. Then, the storage capacity can be reduced.

  However, in the case where an unfilled questionnaire form or its print data does not remain at hand, only the difference cannot be extracted and stored by the above method. Therefore, if the questionnaire is printed with normal ink with questions and answer fields, and if the respondent fills in the writing instrument using the ink that becomes colorless by heating, the collected questionnaire is heated. This is convenient because an unfilled questionnaire sheet can be reproduced by deleting the filled-in portion.

  In this case, scan one of the collected questionnaire forms with a scanner, save the image, and then erase the colorless paint to reproduce the blank questionnaire form (form manuscript). The questionnaire process is to read a questionnaire form with a scanner, generate a form image, and then read the remaining questionnaire forms in order to extract the difference from the form image and save it. If it is performed with a body scanner device and a heat erasing device (for example, an ink jet printer disclosed in Patent Document 1), the work of the operator becomes extremely complicated. In addition, since the questionnaire sheet provided for reproduction stores the image before erasure, that is, the image of the entire sheet, the data format is different from the difference data extracted from the other questionnaire sheets. This work is also required separately.

  The present invention is intended to solve the above problem, and reproduces a form document in which a part drawn with the paint is erased from a document including a part drawn with a paint that becomes colorless when heated, It is another object of the present invention to provide an image reading apparatus capable of efficiently proceeding with an operation of extracting only information on a portion drawn with a paint to be colorless from each original from a difference from a reproduced form original.

  The gist of the present invention for achieving the object lies in the inventions of the following items.

[1] a reading unit that optically reads a document to acquire image information;
A storage unit;
A heater for heating the original to a temperature at which a predetermined paint that is colorless when heated is colorless;
The first original including the portion drawn with the paint is read by the reading unit, first image information is acquired and stored in the storage unit, and then the first original is heated by the heater to form the paint. And then reading the first original with the reading unit to acquire second image information and storing it in the storage unit, and then the difference between the first image information and the second image information The second document including the same drawing content as the image corresponding to the second image information is read by the reading unit to obtain the third image information, and the third image information and the first image information are extracted. A control unit for controlling execution of a reading and extracting operation for extracting information on a difference from the image information of 2;
An image reading apparatus comprising:

  In the above invention, the image information (second image information) of the form original in which the part drawn with the colorless paint is erased from the original containing the part drawn with the paint (colorless paint) that becomes colorless when heated. And the difference information between the image information (first and third image information) of each document and the generated second image information is extracted. Thus, even if there is no unfilled form document, a form document can be generated from a document that has been filled with colorless paint, and the difference between each filled document and the form document can be extracted.

[2] When the reading and extracting operation is completed, the control unit erases the first and third image information, and stores the difference information in the storage unit in association with the second image information. The image reading apparatus according to [1], wherein the image reading apparatus is in a state.

  In the above invention, the first and third image information is deleted, and only the information of the form original image (second image information) and the difference is saved, so that the storage capacity can be saved.

[3] An automatic document transport device that transports a document set on a document table to a predetermined discharge destination through a transport path that passes through a reading position where the reading unit reads the document and a heating position where the heater heats the document. Have
The control unit controls the automatic document feeder in the reading and extracting operation, and the first document is transported from the document table to a discharge destination via the reading position, the heating position, and the reading position in this order. The image reading apparatus according to [1] or [2], wherein the second document is transported from the document table to a paper discharge destination via the reading position.

  In the above invention, the reading operation and the heat erasing process are performed on the document conveyed by the automatic document conveying device.

  According to the image reading apparatus according to the present invention, from the original including the part drawn with the paint that becomes colorless when heated, the erased form original of the part drawn with the paint is generated, and from each original, The operation of extracting only the information of the portion drawn with the paint to be colorless from the difference from the reproduced form document can be efficiently advanced, and the burden on the operator can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration of an image forming apparatus 10 including a function as an image reading apparatus according to an embodiment of the present invention. The image forming apparatus 10 optically reads a document to acquire image information, stores the image information or transmits the image information to an external terminal, reads the document, and based on the image information obtained by the reading. A copy function that prints a copy of a document on recording paper and outputs it, and a printer function that prints and outputs an image obtained by rasterizing print data received from an external terminal onto recording paper. It is configured as a machine.

  The image forming apparatus 10 also erases a document (hereinafter referred to as an erased original) from a document including a part rendered with a paint that is colorless when heated (hereinafter referred to as a colorless paint). This is a read that extracts only the information of the portion drawn with the colorless paint from each completed document added to the form document from the difference from the reproduced form document. It has a function to perform the extraction operation.

  More specifically, in the reading and extracting operation, the first original including the portion drawn with the colorless paint is read, the first image information is acquired and stored, and then the first original is heated by the heater. The form document in which the colorless paint portion is colorless (erased) is reproduced. Thereafter, the form original (first original after erasure) is read to acquire and store the second image information, and the difference information between the first image information and the second image information is extracted and stored. . This difference information corresponds to the information of the portion drawn with the colorless paint in the first document before erasure.

  In the reading and extracting operation, a second document (another document added to the form document) including the same drawing content as the image corresponding to the second image information is read to obtain third image information. The difference information between the image information 3 and the second image information is extracted and stored. This difference information corresponds to the information of the portion of the second document before erasure added to the form document. If there is another document (document added to the form document) following the second document, the same process as that of the second document is continuously performed on the document. In this way, in the reading and extracting operation, the portion drawn with the colorless paint is erased from the first original and the form original is reproduced, and based on the second image information obtained by reading the reproduced form original. Then, only the difference information from the form original is extracted from each original and stored.

  The image forming apparatus 10 includes an automatic document feeder 20, a reading unit 12, a communication unit 13, an image storage unit 14, an operation display unit 15, and a control unit 11 that performs overall control of the operation of the image forming apparatus 10. The printer unit 16 is connected. The control unit 11 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile memory, and the like, which are not shown, as main parts. Various programs are stored in the ROM, and the functions of the image forming apparatus 10 are realized by the CPU executing processes according to these programs. The RAM is used as a work memory that temporarily stores various data when the CPU executes a program. The nonvolatile memory stores user information and various setting information that should be saved even when the power is turned off.

  The automatic document feeder 20 separates and feeds out the documents set on the document table one by one, and conveys them to a predetermined discharge location via the document reading position F and heating position H (see FIG. 2). Fulfills the function of Details of the automatic document feeder 20 will be described later.

  The reading unit 12 performs a function of optically reading a document conveyed by the automatic document conveying device 20 at a reading position F and acquiring image information. The reading unit 12 includes a contact-type line image sensor that irradiates the original with light and receives the reflected light to read the original for one line in the main scanning direction perpendicular to the conveyance direction (sub-scanning direction). The document is read as a two-dimensional image by repeating the reading operation in units of lines in the main scanning direction while moving the document in the conveyance direction (sub-scanning direction) by the automatic document conveyance device 20. . The reading unit 12 converts an analog image signal output from the line image sensor into digital image information and outputs the digital image information.

  The communication unit 13 connects to a network such as a LAN (Local Area Network) or the Internet and performs a function of communicating with various devices on the network. For example, it is used when image information obtained by reading by the reading unit 12 is transmitted to an external terminal or when print data is received from the external terminal.

  The image storage unit 14 is a non-volatile mass storage device used for storing image information obtained by reading by the reading unit 12 and difference information extracted by the reading and extracting operation. Here, the image storage unit 14 includes a hard disk device and its controller.

  The operation display unit 15 has a function of displaying various operation screens, setting screens, selection screens, guidance screens, and the like and a function of receiving various operations from the user. Here, it is composed of a liquid crystal display (LCD ...) that assumes the display function, a touch panel that is formed on the surface of the liquid crystal display and detects the pressed coordinate position, a numeric keypad, a start button, and various operation switches. The

  The printer unit 16 has a function of printing an image corresponding to input image information on a recording sheet and outputting it. The printer unit 16 includes a recording paper conveyance device, a photosensitive drum, a charging device, a laser unit, a developing device, a transfer separation device, a cleaning device, and a fixing device. It is configured as a so-called laser printer that performs formation. Other image forming type printers may be used.

  FIG. 2 shows the automatic document feeder 20 and the reading unit 12. The automatic document feeder 20 includes a document table 21 on which a plurality of documents Q can be placed, a delivery roller 22 that feeds the document Q placed on the document table 21 one by one from the top, and a delivery A normal conveyance path 24 (conveyance path indicated by a broken line (small) in the drawing) for conveying the original Q sent by the roller 22 to the paper discharge tray 23 via the reading position F and the heating position H; And a heater 25 for heating the original passing through the conveyance path 24 to a temperature at which the colorless paint is colorless at a heating position H downstream of the reading position F.

  The normal conveyance path 24 includes a guide wall (not shown) provided along the normal conveyance path 24, a plurality of pairs of conveyance rollers 24 a that are arranged at appropriate positions and sandwich the original from the front and back surfaces, and a reading position F. A contact roller 24b that presses the document from the back so as to be in close contact with the sheet, and a transport motor (not shown) that rotationally drives the transport roller 24a and the contact roller 24b. The normal conveyance path 24 forms a horizontal U-shaped path from the document table 21 to the paper discharge tray 23 below, and the reading position F is slightly downstream from the bent portion of the U-shape. A slit 24c is provided in the guide wall of the normal conveyance path 24 in the portion. The reading unit 12 reads a document through the slit 24c.

  The heater 25 that heats the document at the heating position H is an electric heater that generates heat when energized. The heater 25 is held by a displacement unit 26, and the displacement unit 26 is fixed to a base (not shown) of the automatic document feeder 20. The displacing unit 26 is a paper surface contact position (a position indicated by a solid line in the drawing) where the heating surface of the heater 25 comes into contact with the original whose heating surface passes through the heating position H of the normal conveyance path 24 (here, pressed so as to be in close contact). Then, the heater 25 is displaced to a non-contact position on the paper surface where the heating surface is separated from the document (a position indicated by a one-dot broken line in the drawing). For example, the displacement unit 26 includes a spring that urges the heater 25 to the non-contact position on the paper surface and a solenoid that displaces the heater 25 to the paper surface contact position when energized against the spring.

  The automatic document feeder 20 also reverses the front and back of the document that has passed through the reading position F and sends it again to the normal conveying path 24 at the merging position G upstream of the reading position F (in the drawing). A route indicated by a broken line (large)).

  The switchback path 28 includes a guide wall that forms a document path and a switching claw 29 for switching the document path. The switching claw 29 is normally biased by a spring so that the tip is in a slightly upward normal position (a position indicated by a solid line in FIG. 2). It is displaced to a position (position indicated by a broken line in FIG. 2).

  When the document is fed through the switchback path 28 with its front and back reversed and sent to the merge position G, the following control is performed by the control unit 11. The switching claw 29 is displaced to the reversal position and the rotation direction of the switchback control roller SB is reversed at the timing immediately before the end of the document passes the switchback control roller SB that is the conveyance roller 24a closest to the paper discharge tray 23. . As a result, the document conveyed in the reverse direction by the reversed switchback control roller SB is guided by the switching claw 29 displaced to the reversal position and proceeds on the switchback path 28, from the merge position G to the normal conveyance path 24. Enter again. At this time, the front and back of the document are reversed. Thereafter, when the end of the document traveling on the switchback path 28 has passed through the switching claw 29, control is performed to return the direction of the switching claw 29 and the rotation direction of the switchback control roller SB to normal.

  The document table 21 is provided with a document sensor that detects the presence / absence of a document and the size of the placed document. In addition, sensors for detecting the presence or absence of a document are provided at various locations on the normal transport path 24 and the switchback path 28. Based on the sensor output, the control unit 11 recognizes the timing at which the document has passed the sensor position and detects paper. That is, it detects. For example, the sensor is provided in the vicinity of the upstream of the switchback control roller SB, and the control that reverses the switchback control roller SB with reference to the timing when the sensor detects the end of the document, or the switchback control roller SB Control for returning to the rotation in the direction of, and control for switching the direction of the switching claw 29 are performed.

  FIG. 3 shows an example of the reading setting screen 40 displayed on the operation display unit 15 of the image forming apparatus 10. The display content on the operation display unit 15 is controlled by the control unit 11. On the reading setting screen 40, a “double-sided → double-sided” mode in which both front and back sides of a document are read and printed on both front and back sides of the recording paper is read, and both front and back sides of the document are read and printed on one side (front side) of the recording paper. Either “Double-sided to single-sided” mode, “One-sided to double-sided” mode that reads one side of each document and prints on both sides of the recording paper, or “Single-sided to single-sided” mode that reads one side of the original and prints on one side of the recording paper Select scan settings to select, scan settings to select whether to perform normal scan operations or scan extraction operations, enlargement / reduction settings for scanned documents, and selection of paper size when printing scanned documents with the copy function Operation buttons and guidance messages are arranged and displayed.

  By operating these operation buttons, the user can make various settings relating to document reading and the like. The scan setting is operated when selecting a normal reading button 41 that is operated when selecting a normal reading mode that is an operation mode for performing a normal reading operation, and a reading extraction mode that is an operation mode for performing a reading and extracting operation. A reading extraction mode button 42 is arranged.

  The example of FIG. 3 shows a state in which the “single side → single side” mode is selected as the scan setting, the reading extraction mode is selected as the reading setting, and the same magnification is selected as the enlargement / reduction setting.

  FIG. 4 shows an example of a document (referred to as a form document) having no portion drawn with a colorless paint. This form manuscript 50 is an unfilled questionnaire sheet in which a name field, a question, an answer field, etc. are printed with normal ink (ink that is not erased even when heated by the heater 25). The first page 50 (1) The second page 50 (2) is a part of the two pages.

  FIG. 5 shows an example of completed manuscripts 52 and 54 added to the form manuscript with colorless paint. These were collected from the form manuscript 50 shown in FIG. 4 with the name and answer filled in with a writing instrument using colorless paint, and the first manuscript 52 in which Mr. Suzuki entered the answer and Mr. Sato answered The second copy 54 is written as an example.

  Next, the operation of the image forming apparatus 10 will be described.

  FIG. 6 shows a flow of operations performed by the image forming apparatus 10. When the document is set on the document table 21 by the user, the control unit 11 receives various setting operations related to reading of the document from the user through the reading setting screen 40 (step S101).

  When the user selects the reading / extracting mode by operating the reading / extracting mode button 42 on the reading setting screen 40, the control unit 11 displays a predetermined screen for inquiring the number of sheets constituting one original. It is displayed on the section 15 and accepts the input of the number of sheets. In addition, when the reading extraction mode is selected, the user makes the first original including the part drawn (appended) with the colorless paint on the form original and the same original form original as the first copy. All the second and subsequent originals including the part drawn (added) with paint are set on the original platen 21. In the following examples, description will be made assuming that the first copy original 52 and the second copy original 54 in FIG.

  When a start button (not shown) is operated after the setting on the reading setting screen 40 is completed, the control unit 11 executes the processes after step S102.

  In step S102, it is checked whether or not the reading extraction mode is selected by the setting operation on the reading setting screen 40 (step S102). If the normal reading mode is selected (step S102; No), the normal reading is performed. An operation is performed (step S103).

  Specifically, the control unit 11 does not heat the heater 25 and moves the heater 25 to the non-contact position on the paper surface by the displacement unit 26 (if it is in the non-contact position on the paper surface by default) Maintain). Thereafter, as shown in FIG. 7, the uppermost one of the one or more documents Q placed on the document table 21 is fed out by the feed roller 22, and the document is discharged to the discharge tray through the normal transport path 24. When the original passes through the reading position F, the reading unit 12 reads the original to acquire image information and stores the image information in the image storage unit 14. The process is repeated until there is no document placed on the document 21. In this case, the document is discharged to the discharge tray 23 without being heated at the heating position H.

  When the reading / extracting mode is selected (step S102; Yes), the control unit 11 performs a reading / extracting operation on the document set on the document table 21.

  Specifically, the control unit 11 heats the heater 25 to raise the temperature of the colorless paint to a temperature at which it can be colorless. After completion of the temperature increase, it is determined whether or not the next document to be sent out from the document table 21 is the first copy (step S104). Whether it is the first copy or not is determined based on the number of copies of one original input by the user in the job input operation. That is, the number of sheets sent from the document table 21 is counted (initial value is set to 0). If the count value is less than the number of one copy of the document input by the user, it is determined as the first copy, and the count value is If the number of originals input is greater than or equal to the number of originals input from, it is determined that the second and subsequent originals.

  If the next document to be sent out from the document table 21 is the first document (step S104; Yes), the top of the documents Q placed on the document table 21, as shown in FIG. One sheet is fed by the feed roller 22 and conveyed to the paper discharge tray 23 through the normal conveyance path 24, and when the document passes the reading position F during the conveyance, the reading unit 12 performs line unit. Are repeatedly performed to obtain two-dimensional image information (first image information) of the original, and this is the first copy of the Nth page (N is the page number from the top of the original of each copy). Is temporarily stored in the image storage unit 14 as image information (step S105).

  For example, when the first page 52 (1) of the first original in FIG. 5 is conveyed and processed, the image information of the original is saved as the first image information of the first page of the first copy. When the second page 52 (2) of the first original is being processed, the image information of the original is stored as the first image information of the first second page.

  Further, when the original passes through the heating position H, the heater 25 is moved to the non-contact position on the paper surface by the displacement unit 26 to heat the original and is drawn (added) with the colorless paint contained in the original. The erased portion is erased (step S106). Note that the heating temperature of the heater 25 is the temperature at which the colorless paint to be erased becomes colorless, and the document conveyance speed through the normal conveyance path 24 (the local area on the document contacts the heating surface of the heater 25). Time). Specifically, the temperature is set to a temperature at which the colorless paint on the conveyed document is surely colorless while passing through the heating surface of the heater 25.

  When the end of the original conveyed toward the paper discharge tray 23 passes the switching claw 29 and reaches just before the switchback control roller SB, as shown in FIG. Is moved to the non-contact position on the paper surface, and the original is sent again to the merging position G through the switchback path 28. The original is further conveyed along the normal conveyance path 24, and the reading position F is passed again. At this time, since the document is reversed, the reading unit 12 does not perform reading.

  After that, when the end of the document passes the switching claw 29 and reaches just before the switchback control roller SB, the document is again sent to the merging position G through the switchback path 28, and is passed through the reading position F to the discharge tray 23. The paper is discharged. At this time, since the front and back of the document are returned to the original state, when the document passes the reading position F, the reading unit 12 reads the document to acquire image information (second image information). Are stored in the image storage unit 14 as image information (form image) of the form document of the Nth page of the document (N is the page number from the beginning of the document of each part) (step S107).

  For example, when the first page 52 (1) of the first copy of the original shown in FIG. 5 is being processed, the additional writing portion by the colorless paint is erased from the first page 52 (1) of the first copy of the original. The image information corresponding to the first page 50 (1) of the form document 50 shown in FIG. 4 is stored as the first page form image (second image information). In the case where the second page 52 (2) of the first original in FIG. 5 is conveyed and processed, the additional writing portion by the colorless paint is erased from the second page 52 (2) of the first original. The image information corresponding to the second page 50 (2) of the form document 50 shown in FIG. 4 is stored as the second page form image (second image information).

  In addition, the control unit 11 reads the first image information of the first copy N page read and temporarily stored in step S105 and the second image information (form image) of the first copy N page saved in step S107. The difference is extracted (step S108), and the extracted difference information is stored in the image storage unit 14 in association with the form image of the Nth page as difference information of the first Nth page (step S109).

  For example, when the first page 52 (1) of the first original in FIG. 5 is conveyed and processed, the first image information (the image corresponding to the original 52 (1) in FIG. 5) and the second The difference from the image information (form image corresponding to the form original 50 (1) in FIG. 4) is the difference image 56 (1) in FIG. When the second page 52 (2) of the first original in FIG. 5 is conveyed and processed, the first image information (the image corresponding to the original 52 (2) in FIG. 5) and the second The difference from the image information (form image corresponding to the form document 50 (2) in FIG. 4) is the difference image 56 (2) in FIG. Here, the control unit 11 performs character recognition processing on the difference image 56, and stores the recognized character information as difference information for the first copy of the Nth page.

  Subsequently, the control unit 11 determines whether or not the next document exists on the document table 21 based on the detection result of the document sensor provided on the document table 21, and when the next document exists (step S114). ; Yes), the process returns to step S104 and continues. If there is no next original (step S114; No), the process is terminated. The processing from step S105 to step S109 is repeated for the number of documents constituting the first copy.

  In the case of the second and subsequent copies (here, the M-th copy) (step S104; No), as shown in FIG. 8A, the uppermost one of the originals Q placed on the original table 21 is displayed. The sheet is fed out by the feed roller 22 and conveyed to the paper discharge tray 23 through the normal conveyance path 24, and when the document passes the reading position F during the conveyance, the reading unit 12 performs line unit measurement. The reading operation is repeatedly performed to obtain two-dimensional image information (third image information) of the document, and this is the Mth page and the Nth page (N is the page number from the top in the document of each section). ) Is temporarily stored in the image storage unit 14 (step S110).

  For example, when the first page 54 (1) of the second copy original in FIG. 5 is conveyed and processed, the image information corresponding to the original is the third image information of the second copy first page. Temporarily saved. When the second page 54 (2) of the second original is being processed, the image information corresponding to the original is temporarily stored as the third image information of the second page of the second copy.

  Further, when the original passes through the heating position H, the heater 25 is moved to the non-contact position on the paper surface by the displacement unit 26 to heat the original and is drawn (added) with the colorless paint contained in the original. The existing portion is erased (step S111).

  Next, the control unit 11 calculates a difference between the third image information of the Mth page and the Nth page read and temporarily stored in step S111 and the Nth page form image (second image information) stored in step S107. The extracted difference information is stored in the image storage unit 14 in association with the form image of the Nth page as difference information of the Mth page of the Nth page (step S113).

  For example, when the first page 54 (1) of the second original in FIG. 5 is conveyed and processed, the first image information (the image corresponding to the original 54 (1) in FIG. 5) and the second The difference from the image information (form image corresponding to the form document 50 (1) in FIG. 4) is the difference image 58 (1) in FIG. When the second page 54 (2) of the second original in FIG. 5 is conveyed and processed, the first image information (the image corresponding to the original 54 (2) in FIG. 5) and the second image are displayed. The difference from the information (form image corresponding to the form document 50 (2) in FIG. 4) is the difference image 58 (2) in FIG. The control unit 11 performs character recognition processing on the difference image 58, and stores the recognized character information as difference information for the second copy of the Nth page.

  Subsequently, the control unit 11 determines whether or not the next document exists on the document table 21 based on the detection result of the document sensor provided on the document table 21, and when the next document exists (step S114). ; Yes), the process returns to step S104 and continues. If there is no next original (step S114; No), the process is terminated. The processing from step S110 to step S113 is performed for all the second and subsequent originals. Further, since the control unit 11 recognizes the number of sheets constituting one copy, it recognizes that each document is the Nth page of the Mth copy and performs the above processing.

  FIG. 10 exemplifies data stored in the image storage unit 14 at the time when the operation of the reading and extracting mode performed on the first copy original 52 and the second copy original 54 in FIG. The form images of the first page and the second page are stored as an image data file (form image file 60), and a difference information list 64 is stored in association with the form image file 60. In the difference information list 64, the difference information acquired in steps S108 and S112 is registered. The association between the form image file 60 and the difference information list 64 is, for example, adding the file name of the form image file 60 as the header information of the difference information list 64 or the head of the difference information list 64 as the header information of the form image file 60. Add addresses and list names. Note that the control unit 11 erases the image information (first image information and third image information) obtained by reading each document after obtaining the difference information (at least before the completion of the reading and extracting operation).

  As described above, after the first copy of the original is read, the colorless paint of the original is colorless, and the original after the colorless is read again to obtain an image (form image) corresponding to the form original. A form image can be generated even when a document and its print data are not at hand. Further, since the difference information is acquired using the form image acquired from the first copy for the second and subsequent copies, it is not necessary to read again after erasing the colorless paint for the second and subsequent copies. It is possible to shorten the processing time according to the above.

  In addition, the form image (form image file 60) and difference information (difference information list 64) are saved, and the first and third image information are deleted when the reading and extracting operation is completed, so that the memory required for storing necessary information is stored. The capacity can be reduced, and for example, the necessary storage capacity can be greatly reduced as compared with the case where the images read for all the originals are stored as they are.

  Also, since the colorless paint on each document is automatically erased after the document is read, there is no longer a possibility that the document will be left for a long time until it is erased by heating after it is digitized. Is secured. In addition, since the automatic document feeder 20 feeds the documents one by one from the document table 21 and sequentially processes them, even when processing a large number of documents, the burden on the user is small and the processing time can be shortened. .

  Further, after completion of the reading and extracting operation, each original is erased with the colorless paint and returned to the form original, so that it can be reused as, for example, an unfilled questionnaire sheet.

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.

  For example, in the embodiment, the user inputs the number of documents constituting one copy and automatically recognizes the boundary of each portion based on the number, but the method for recognizing the number of copies constituting one copy is as follows. It is not limited to this. For example, the first copy and the second and subsequent copies may be set separately on the document table 21. That is, at first, only the first copy of the document is set on the document table 21, all the documents set on the document table 21 are processed as being the first copy, and in this process, the first copy is processed. Recognize the number. Then, after the processing for all the first set of originals set on the original platen 21 is completed, a guidance display for setting the second and subsequent originals on the original platen 21 is displayed on the operation display unit 15. If the user receives an operation for completing the second and subsequent document sets from the user, the processing for the second and subsequent copies may be performed based on the number of copies constituting one copy recognized earlier. Further, when the same form image is acquired, it may be configured to automatically recognize up to the front as the first copy.

  In the embodiment, the colorless paint is also colorlessd by the heater 25 for the second and subsequent parts, but the second and subsequent parts may not be colorless. Moreover, you may comprise so that a user can select whether the 2nd copy or later is colorless. The second and subsequent copies of the original may be written with normal ink in the additional portion or the like, or may be an original without a portion drawn with a colorless paint. In this case, the second and subsequent copies may be set so as not to be colorless by heating.

  In the embodiment, the case where the document is read in a so-called flow-reading format in which the document is moved with respect to the fixed reading position F is illustrated, but the document placed stationary on the platen glass is read by the reading unit. It may be configured to read two-dimensionally by moving. In this case, the automatic document feeder is configured to convey the document from the document table onto the plan glass and to convey the document from the platen glass to the paper discharge tray after reading (or after reading and erasing). The heater is provided on the document surface side of the platen cover that covers the glass surface of the platen glass or the platen glass on which the document is placed from the document side, and is configured to decolorize the document on the platen glass. It is good to use.

  Further, even an arrangement without an automatic document feeder can operate as an image reading apparatus according to the present invention. For example, after having the user set the first copy of the first document on the plan glass, this document is read (first image information acquisition), and then the document on the platen glass is heated with a heater. Then, the colorless document is read again (second image information acquisition), and difference information between the first image information and the second image information is acquired and stored. When there are two or more copies of one copy, the above work / operation is repeated. Thereafter, a message prompting the user to set the second copy of the original on the platen glass is displayed on the operation display unit 15. When the second copy of the first original is set on the platen glass, this is read (third). Acquisition of the image information), the difference information between the second image information and the third image information is acquired and stored. When there are two or more originals constituting one copy, the above operations and operations are repeated for the second original. If there is a third copy or later, the same work / operation as the second copy is repeated.

  Further, in the embodiment, the heater 25 is displaced between the paper surface contact position and the paper surface non-contact position by the displacement unit 26. However, if the heater 25 is heated or cooled in a short time, the heater 25 may be fixed at a non-contact position on the paper surface. In addition, when the heating erasing process is unnecessary, the heater 25 is configured to be retracted to the non-contact position on the paper surface, thereby suppressing deterioration of the heating surface due to contact between the heating surface and the paper surface.

  Also, layout analysis is performed on the form image to recognize the name field and answer field area, and only the images in the name field and each answer field area are extracted as difference images from the first and third image information. Thus, the difference information may be obtained. In the embodiment, the character information obtained by character recognition of the difference image is stored as difference information. However, the difference image may be stored.

  In the embodiment, the image forming apparatus 10 including the printer unit is illustrated, but a printer function or the like is not essential.

1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. 1 is an explanatory diagram illustrating a configuration of an automatic document feeder included in an image forming apparatus according to an embodiment of the present invention. FIG. FIG. 6 is a front view illustrating an example of a reading setting screen displayed on the operation display unit of the image forming apparatus according to the embodiment of the present invention. It is explanatory drawing which shows an example of a form original document. FIG. 5 is an explanatory view exemplifying a manuscript after filling in the form manuscript of FIG. 4 with a writing instrument using a colorless paint. 6 is a flowchart illustrating an operation related to reading of a document performed by the image forming apparatus according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating a document conveyance path in a normal reading mode. FIG. 6 is an explanatory diagram illustrating a document conveyance path in a reading extraction mode. FIG. 6 is an explanatory diagram showing a difference image extracted from the difference between the completed document in FIG. 5 and the form document in FIG. 4. It is explanatory drawing which shows an example of a form image file and a difference information list.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 11 ... Control part 12 ... Reading part 13 ... Communication part 14 ... Image memory | storage part 15 ... Operation display part 16 ... Printer part 20 ... Automatic document feeder 21 ... Original stand 22 ... Sending roller 23 ... Paper discharge tray 24 ... Normal transport path 24a ... Transport roller 24b ... Contact roller 24c ... Slit 25 ... Heater 26 ... Displacement unit 28 ... Switchback path 29 ... Switching claw 40 ... Read setting screen 41 ... Normal read button 42 ... Read extraction mode button 50 ... Form document 52 ... First copy document 54 ... Second copy document 56, 58 ... Differential image 60 ... Form image file 64 ... Differential information list F ... Reading position G ... Merge position H ... Heating position SB ... Switchback control roller Q ... manuscript

Claims (3)

A reading unit that optically reads a document to acquire image information;
A storage unit;
A heater for heating the original to a temperature at which a predetermined paint that is colorless when heated is colorless;
The first original including the portion drawn with the paint is read by the reading unit, first image information is acquired and stored in the storage unit, and then the first original is heated by the heater to form the paint. And then reading the first original with the reading unit to acquire second image information and storing it in the storage unit, and then the difference between the first image information and the second image information The second document including the same drawing content as the image corresponding to the second image information is read by the reading unit to obtain the third image information, and the third image information and the first image information are extracted. A control unit for controlling execution of a reading and extracting operation for extracting information on a difference from the image information of 2;
An image reading apparatus comprising: When the reading and extracting operation is completed, the control unit erases the first and third image information, and stores the difference information in the storage unit in association with the second image information. The image reading apparatus according to claim 1. An automatic document feeder that conveys a document set on a document table to a predetermined discharge destination through a conveyance path that passes through a reading position where the reading unit reads the document and a heating position where the heater heats the document;
The control unit controls the automatic document feeder in the reading and extracting operation, and the first document is transported from the document table to a discharge destination via the reading position, the heating position, and the reading position in this order. The image reading apparatus according to claim 1, wherein the second document is conveyed from the document table to a paper discharge destination via the reading position.

Images