JP2007325090A - Image forming apparatus and toner adjusting method of image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and a toner adjusting method of the image forming apparatus that eliminate the need to input a target value for adjustment and perform the adjustment so that image data read out of the top surface of a document and image data read out of the reverse surface have the same color tone. <P>SOLUTION: When setting of target data is decided (SP2), an adjustment sheet for CIS element adjustment is placed on an original table. When it is decided that a start key is pressed (SP4), a pattern for lightness adjustment is read out by a CCD element and computed to store digital data as a target value in an EEPROM (SP5), and an adjustment sheet for resolution adjustment is placed on the original table; when it is decided that the start key is pressed (SP7), a pattern for resolution adjustment is read by the CCD element and computed to store digital data as a target value in the EEPROM (SP8). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a color adjustment method for the image forming apparatus, and more particularly to an image forming apparatus for forming a color image and a color adjustment method for the image forming apparatus.

  In an image forming apparatus such as a color laser printer, a color copier, a scanner, or a digital multifunction machine having a facsimile function, it is necessary to adjust an image output position on a recording sheet. This is because the transport accuracy varies due to a difference in recording paper size, a transport path for each paper feed cassette, and the like.

  An image forming apparatus having a reading device that reads a double-sided document automatically feeds the document by an automatic document feeding mechanism, reads the surface of the double-sided document with a CCD (Charge Coupled Device) element, and reads the back side of the CIS (Contact Image). Sensor: Contact image sensor) Reading is performed. For this reason, the positional relationship between the front surface and the back surface may be relatively large. Further, the color tone including the brightness and resolution of the read output on the front and back sides of the document may be different.

  In order to eliminate such inconvenience, it is necessary to perform position adjustment and hue adjustment. The reading device can also read the original by the CCD element even when the user places the original on the original table without automatically feeding the original by the automatic original feeding mechanism.

  Adjustment in such an image forming apparatus is performed using an adjustment sheet for CCD element adjustment and an adjustment sheet for CIS element adjustment. First, an adjustment sheet for CCD element adjustment is automatically fed. Without being placed on the document table, adjustments related to the CCD element are performed by adjusting the position, adjusting the brightness, and adjusting the resolution. Thereafter, an adjustment sheet for adjusting the CCD element is automatically fed, and with respect to the surface reading by the CCD element, since the brightness adjustment and the resolution adjustment have already been completed, only the position adjustment is performed. Thereafter, using the adjustment sheet for CIS element adjustment, position adjustment relating to reading, brightness adjustment, and resolution adjustment are performed on the CIS element.

  The adjustment sheet for adjusting the CIS element has different adjustment patterns formed in advance for position adjustment, brightness adjustment, and resolution adjustment. In the brightness adjustment and resolution adjustment, the respective colors are adjusted. The target value is entered on the adjustment sheet, and it is necessary to adjust it toward the target value. In the past, there has been a problem that the target value is likely to cause an input error because the service person has to manually input the target value.

On the other hand, in Japanese Patent Laid-Open No. 2006-5487 (Patent Document 1), an adjustment image output on both sides of a recording sheet is read, a front image and a back image are combined and displayed, and each adjustment displayed is displayed. An image output system is described in which an image is moved, a position change of each moved adjustment image is calculated, and an adjustment value is set according to the calculated position change amount.
JP 2006-5487 (summary, FIG. 3)

  The image output system described in Patent Document 1 sets an adjustment value according to the calculated position change amount, and cannot be applied to color adjustment even if it can be applied to position adjustment.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is not to input a target value for adjustment, and image formation that can be adjusted so that the color of the image data read from the front side of the document and the image data read from the back side are the same. The present invention provides a color adjustment method for an image forming apparatus and an image forming apparatus.

  According to the present invention, a first reading unit that reads one side of a document, a second reading unit that reads the other side of the document, and an adjustment sheet for adjusting a hue are read by the first reading unit. And target value data setting means for setting the output hue data as a target value for adjusting the hue of the output of the second reading means when the adjustment sheet is read by the second reading means.

  Specifically, a document table on which a document to be read by the first reading unit is placed, one side of the document is read by the first reading unit, and the other side of the document is read by the second reading unit. And an automatic document feeding mechanism that automatically feeds the document, and the target value data setting means uses the automatic feeding mechanism to convert the hue data read by the first reading means with the adjustment sheet placed on the document table. When the adjustment sheet is automatically fed, it is set as a target value for adjusting the hue of the read output of the second reading means.

  Preferably, fixed data storage means for storing predetermined fixed data for adjusting the hue, hue data read by the first reading means, and predetermined fixed data stored in the fixed data storage means. Selecting means for selecting which data is to be set as the target value in the target value data setting means.

  Preferably, the hue includes brightness and resolution, and the adjustment sheet is formed with a brightness pattern for adjusting brightness and a resolution pattern for adjusting resolution.

  Another aspect of the present invention is a color adjustment method for an image forming apparatus, in which one side of a document is read by a first reading unit and the other side of a previous document is read by a second reading unit. The adjustment sheet for adjusting the hue of the output is read by the first reading unit, the hue adjustment data of the read output is set as a target value, the adjustment sheet is read by the second reading unit, and the reading is performed. Adjusting the hue of the output of the second reading means so that the output hue data becomes the hue data that is the target value.

  Specifically, a position adjustment pattern, a brightness adjustment pattern for adjusting the hue, and a resolution adjustment pattern are formed on the adjustment sheet, and the position adjustment pattern is read by the first reading unit. Adjusting the reading position of the second reading means, and after adjusting the reading position, the brightness and the resolution are adjusted as the hue adjustment.

  Preferably, the adjustment sheet includes a first adjustment sheet on which a position adjustment pattern is formed, and a second and third adjustment sheet on which a brightness adjustment pattern and a resolution adjustment pattern for hue adjustment are formed, respectively. An adjustment sheet, and a step of reading a position adjustment pattern from the first adjustment sheet by the first reading unit to adjust a reading position of the second reading unit, and after adjusting the reading position, The brightness adjustment pattern and the resolution adjustment pattern are sequentially read from the third adjustment sheet, and the brightness and resolution are adjusted as hue adjustment.

  According to this invention, the adjustment sheet for adjusting the hue is read by the first reading unit, the hue data of the read output is set as the target value, and the adjustment sheet is read by the second reading unit. Thus, when adjusting the hue of the read output, adjustment is performed using the set target value, so that it is not necessary to manually input the target value for adjustment, and the original is read by the first and second reading means. Can be adjusted so that the hues of the image data when reading is the same.

  FIG. 1 is a block diagram of a digital multifunction peripheral as an example of an image forming apparatus 30 according to an embodiment of the present invention. In FIG. 1, the image forming apparatus 30 includes a control unit 31. Further, the reading unit 1 connected to the control unit 31 and controlled, an operation unit 32 that operates as a selection unit, a fixed data storage unit, and target value data setting. An EEPROM (Electrically Erasable PROM) 33 that operates as a means, a display unit 34, a printing unit 35, and a communication unit 36 are provided.

  As will be described later with reference to FIG. 2, the reading unit 1 can read both sides of a document. The operation unit 32 includes a start switch for instructing reading of a document, a numeric keypad for setting the number of copies, keys for instructing various adjustments, and the like. The EEPROM 33 stores, as digital data, a target value that is data for adjusting hues including brightness and resolution, and a default value that is predetermined fixed data. A display unit 34 displays the number of copies to be printed. The printing unit 35 prints an image based on the read image data or image data given from the outside. The communication unit 36 is an interface with an external communication line when using the digital multi-function peripheral as an example of the image forming apparatus 30 as a facsimile apparatus.

  FIG. 2 is a side sectional view of the reading unit 1 shown in FIG. In FIG. 2, the reading unit 1 has an automatic feeding mechanism that automatically feeds a document. A method of automatically feeding and reading a document by the automatic feeding mechanism, and a method of reading a document placed on a document table. Both of them can be read.

  In FIG. 2, a paper feed tray 2 is arranged so that the front is lowered, and a plurality of documents 3 are placed thereon and automatically fed. By operating a start key (not shown) of the operation unit 32, the document 3 is sent to the conveyance path 7 one by one by the sheet feeding roller 4, the separation roller 5, and the registration roller 6. A reading position 8 is provided in the conveyance path 7, and the document 3 is conveyed to the reading position 8 by the platen roller 9. The sheet feeding roller 4, the separation roller 5, the registration roller 6, and the platen roller 9 operate as an automatic feeding mechanism that automatically feeds the document 3 on the sheet feeding tray 2.

  A glass 10 is fitted in the reading position 8. A reader 11 is provided below the glass 10. The reader 11 includes a lamp 12, mirrors 13, 14, 15, a lens 16, and a CCD element 17 that operates as a first reading unit, and reads an image from the surface (one surface) of the document 3. That is, light is irradiated from the lamp 12 to the surface of the document 3 through the glass 10, and the reflected light reflected from the surface of the document 3 by the mirrors 13, 14, 15 is guided to the CCD element 17 through the lens 16. Then, the image data of the document 3 is read. A glass 20 acting as a document table is fitted on the right side in FIG.

  A CIS element 21 that operates as second reading means is disposed opposite to the shading roller 23 on the downstream side of the conveyance path 7 from the reading position 8. A lamp 22 is built in the CIS element 21. The CIS element 21 reads an image from the back surface (the other surface) when the automatically fed document 3 is a double-sided document. The shading roller 23 conveys the document 3. The read original 3 is discharged to a discharge tray 25 by a discharge roller 24.

  The paper feeding roller 4, the separation roller 5, the resist roller 6, the platen roller 9, the CIS element 21, the shading roller 23, and the like are covered with a cover 26. The cover 26 together with the discharge tray 25 covers the glass 10 and 20 surfaces. It can be opened and closed. With the cover 26 opened, the document 3 is placed on the glass 20, and the start key is operated to drive the reader 11 to the right in FIG. 2, thereby placing the document 3 placed on the glass 20. Can be read.

  FIG. 3 is a diagram illustrating an example of an adjustment sheet 40 for adjusting image formation by the image forming apparatus 30. In FIG. 3, for example, A4 size paper is used as the adjustment sheet 40. On the adjustment sheet 40, a black pattern 41 for position adjustment, a pattern 42 for brightness adjustment for color adjustment, and a pattern 43 for resolution adjustment are formed.

  The black pattern 41 is printed along each end portion of the adjustment sheet 40 so as to intersect with each other in a belt shape, and by reading the black pattern 41, the leading edge timing adjustment, the center position adjustment, and the same magnification adjustment are performed. The position is adjusted.

  The adjustment sheet 40 includes black (N3.0), white, gray (N8.5), gray (N7.7), gray (N6.5), gray (N5) as a pattern 42 for adjusting the brightness. .0) is printed in a strip-like pattern colored in each color. The brightness adjustment is performed by reading the pattern 42 for brightness adjustment. N represents a Munsell color number.

  Further, the adjustment sheet 40 has blue (B), cyan (C), magenta (M), black, yellow mixed colors of cyan (C) and magenta (M) as a resolution adjustment pattern 43. A band-like pattern of (Y), red (R) in which magenta (M) and yellow (Y) are mixed, and green (G) in which cyan (C) and yellow (Y) are mixed is printed. By reading the color of the pattern 43 for adjusting the resolution, each adjustment of resolution including color shift and color is performed.

  The adjustment sheet 40 is also provided with a jitter adjustment pattern, but is not shown. Further, the adjustment sheet 40 may be divided into two parts, that is, a part including a black pattern 41 and a pattern 42 for adjusting brightness and a part including a pattern 43 for adjusting resolution. Alternatively, only the first adjustment sheet on which only the black pattern 41 is formed, the second adjustment sheet on which only the pattern 42 for brightness adjustment is formed, and only the pattern 43 for resolution adjustment are formed. Alternatively, a third adjustment sheet may be used.

  Such an adjustment sheet 40 is used for adjusting the hue of the CCD element 17 (hereinafter referred to as an adjustment sheet 40a), and is used for adjusting the hue of the CIS element 21 (hereinafter referred to as an adjustment sheet 40b). ) And are prepared in advance. In the following description, a black pattern 41, a light and darkness adjustment pattern 42, and a resolution adjustment pattern 43 are formed on each of the adjustment sheets 40a and 40b. Description will be made assuming that the position adjustment by the CCD element 17 and the CIS element 21, the brightness adjustment of the read output, and the resolution adjustment are performed using the sheet 40a and the adjustment sheet 40b for the CIS element. Since the CIS 21 reads the back side of the document, each pattern of the adjustment sheet 40b is formed on the back side.

  First, the service man operates a key for instructing position adjustment in the adjustment mode on the operation unit 32. The service person places the adjustment sheet 40 a for the CCD element on the glass 20 of the reading unit 1 shown in FIG. 2 and causes the reader 11 to read the adjustment sheet 40 a. By setting the position adjustment, a reading area by the CCD 17 is set so that only the black pattern 41 portion of the adjustment sheet 40a is read, and software processing is performed based on the image data of the black pattern 41 read from the adjustment sheet 40a. Thus, position adjustment such as tip timing adjustment, center position adjustment, and equal magnification adjustment is performed.

  Subsequently, the service person operates a key for instructing brightness adjustment from the operation unit 32. By setting the brightness adjustment, the control unit 31 sets the reading area by the CCD element 17 so as to read the pattern 42 portion for the brightness adjustment of the adjustment sheet 40a. Each image data of black (N3.0), white, gray (N8.5), gray (N7.7), gray (N6.5), and gray (N5.0) is read from each pattern, and the read image Based on the data, the input γ adjustment, which is a brightness adjustment, is performed. Here, the gradient of the characteristic curve indicating the brightness / darkness reproducibility of the image information is referred to as gradation, and the linear change portion of this characteristic curve is referred to as γ. The input γ adjustment is to adjust the linearity of the characteristic curve.

  Subsequently, the service person operates a key for instructing resolution adjustment from the operation unit 32. By setting the resolution adjustment, the reading area of the CCD 17 is set so that the controller 31 reads the pattern 43 portion for adjusting the resolution of the adjustment sheet 40a. Then, blue (B), cyan (C), magenta (M), black, yellow (Y), magenta (M), and yellow (Y) in which cyan (C) and magenta (M) are mixed from the pattern 43. Each color image data of red (R), which is a color mixture of cyan (C), and green (G), which is a color mixture of cyan (C) and yellow (Y), is read, and color misregistration is adjusted from the read image data. Further, MTF adjustment that is resolution adjustment is performed by calculation from the read image data, and matrix adjustment that is color adjustment is performed so that the read image data matches the target value. Here, the resolution of the image information is represented by the number of pixels in the vertical and horizontal directions, but MTF (Modulation Transfer Function) is used to quantitatively represent the characteristics in the intermediate frequency pattern. The MTF / matrix adjustment is a resolution adjustment.

  By this series of adjustments, position adjustment when the reading unit 1 reads the document 3 placed on the glass 20 and brightness and resolution adjustment when the document 3 is read by the CCD element 17 included in the reader 11. Ends.

  If the memory capacity in the control unit 31 is large, the black pattern 41, the brightness adjustment pattern 42, and the resolution adjustment pattern 43 are read from the adjustment sheet 40a to read the read data in one reading. It may be stored in a memory, and position adjustment, brightness adjustment, and resolution adjustment may be performed based on the stored read data.

  Subsequently, the service person automatically feeds the adjustment sheet 40a by the reading unit 1 to perform surface adjustment. In the surface adjustment, the CCD element 17 of the reading unit 1 reads the image data of the black pattern 41 from the adjustment sheet 40a, and performs position adjustment such as tip timing adjustment, center position adjustment, and equal magnification adjustment when the document is automatically fed. Do. Since the brightness and resolution adjustment when read by the CCD element 17 has been completed by the previous adjustment, only the position adjustment is performed in the surface adjustment. The adjustment so far is the same as the conventional one.

  Since the back surface of the document 3 is read by the CIS element 21 instead of the CCD element 17, it is necessary to match the brightness and resolution of the image data read from the back surface of the document 3 and the image data read from the front surface of the document 3. There is. For this reason, in the rear surface adjustment, it is necessary to perform position adjustment, brightness adjustment, and resolution adjustment. The adjustment method will be specifically described below.

  4 and 5 are flowcharts for explaining the back surface adjustment operation of the image forming apparatus 30 according to the embodiment of the present invention.

  In step (abbreviated as SP in the drawing) SP1, the control unit 31 determines whether or not the back surface adjustment mode is set, and when the service person operates the operation unit 32 to set the back surface adjustment mode, It is determined that the adjustment mode is set. In step SP2, it is determined whether the target data is set or the default value is set as the target value.

  If the service person operates the operation unit 32 and selects setting of the target data, in step SP3, the control unit 31 sets the adjustment sheet 40b for the CIS element and presses the start key in order to adjust the brightness. As shown in FIG. The service person sets the pattern surface of the adjustment sheet 40 b on the glass 20 of FIG. 2 and presses the start key of the operation unit 32. If it is determined in step SP4 that the start key has been pressed, the reader 11 of the reading unit 1 shown in FIG. 2 is driven in step SP5, and the CCD element 17 uses the CCD element 17 to adjust the brightness from the adjustment sheet 40b. The pattern 42 is read. The control unit 31 calculates a target value for brightness adjustment from the read value and stores it in the EEPROM 33 as digital data.

  In step SP6, the adjustment sheet 40b is set on the glass 20 for resolution adjustment, and displayed on the display unit 33 so as to operate the start key. The service person views the display, sets the adjustment sheet 40b on the glass 20, and operates the start key. If it is determined in step SP7 that the start key has been pressed, each image data of the resolution adjustment pattern 43 is read by the CCD element 17 in step SP8. The controller 31 calculates a target value for resolution adjustment from the read value and stores it in the EEPROM 33 as digital data.

  When the service person has already set the target value and wants to execute only the automatic adjustment, the service person sets the default value as the target value without setting the target value. Manipulate. The default value is set so that it can be used as a target value when it is not necessary to perform the setting mode again, such as when only automatic adjustment fails. If it is determined in step SP2 that the target value is not set, the default values of brightness and resolution stored in advance in the EEPROM 33 are stored as target values in another storage area of the EEPROM 33.

  Thus, the adjustment sheet 40b for adjusting the CIS element 21 can be read by the CCD element 17 and set as a target value for adjusting the brightness and resolution.

  In the above description, the brightness adjustment pattern 42 and the resolution adjustment pattern 43 are read separately from the adjustment sheet 40b. However, if the memory capacity in the control unit 31 is large, the brightness is adjusted. The adjustment pattern 42 and the resolution adjustment pattern 43 may be read by one reading and the target value may be stored in the EEPROM 33.

  In the above description, the adjustment sheet 40b for the CIS element is placed on the glass 20 which is the document table, the patterns 42 and 43 are read by the CCD element 17, and the target values of brightness and resolution are stored in the EEPROM 33. However, the adjustment sheet 40b may be fed by the automatic feeding mechanism, the patterns 42 and 43 may be read by the CCD element 17, and the brightness and resolution target values may be stored in the EEPROM 33.

  Next, automatic adjustment of the back surface shown in FIG. 5 is started. In step SP10, it is determined whether or not automatic adjustment is started. If automatic adjustment is not started, other processing is performed. If automatic adjustment is started, in step SP11, adjustment is performed for position adjustment. The sheet 40b is set and displayed on the display unit 34 so as to press the start key.

  The service person views the display, sets the adjustment sheet 40b in the reading unit 1, and operates the start key. In step SP12, the control unit 31 determines that the start key has been operated. In step SP13, the control unit 31 automatically feeds the adjustment sheet 40b, and the CIS element 21 of the reading unit 1 sets the black pattern 41 for position adjustment. Have them read. Based on the read data, the control unit 31 performs position adjustment such as leading edge timing adjustment, center position adjustment, and equal magnification adjustment for reading the document 3 with the CIS element 21 by software processing.

  When it is determined in step SP14 that the position adjustment has been completed, in step SP15, the adjustment sheet 40b is set for brightness adjustment and displayed on the display unit 34 so as to operate the start key. The service person views the display and sets the adjustment sheet 40b in the reading unit 1 and operates the start key. In step SP16, the control unit 31 determines that the start key has been operated. In step SP17, the control unit 31 automatically feeds the adjustment sheet 40b, and the CIS element 21 of the reading unit 1 creates a pattern 42 for adjusting the brightness. Have them read. In step SP18, target value data for brightness adjustment is read from the EEPROM 33. The control unit 31 adjusts the brightness so that the image data matches the target value data based on the pattern 42 for brightness adjustment read from the adjustment sheet 40b.

  In step SP19, it is determined whether or not the brightness adjustment has been completed. If it has been completed, in step SP20, the adjustment sheet 40b is set for resolution adjustment, and the start key is operated. . The service person views the display and sets the adjustment sheet 40b in the reading unit 1 and operates the start key. In step SP21, the control unit 31 determines that the start key has been operated. In step SP22, the control unit 31 automatically feeds the adjustment sheet 40b and reads the pattern 43 for resolution adjustment by the CIS element 21 of the reading unit 1. Let In step SP23, target value data for adjusting the resolution is read from the EEPROM 33. The resolution is adjusted so that the image data matches the target value data based on the resolution adjustment pattern 43 read from the adjustment sheet 40b.

  If it is determined in step SP24 that the resolution adjustment has been completed, the adjustment result is displayed on the display unit 34 in step SP25. If each adjustment is completed normally, for example, “00” is displayed, and if an error occurs in any of the adjustments, the corresponding error code is displayed with a number other than “00”.

  For example, in the position adjustment, the data read from the adjustment sheet 40b is not for position adjustment, or the error is read when the adjustment sheet 40b is placed obliquely, or the adjusted value falls outside the adjustment range. This is the case. In the brightness adjustment and resolution adjustment, the data read from the adjustment sheet 40b is not for brightness adjustment or resolution adjustment, the adjustment sheet 40b is read obliquely, or the adjustment sheet 40b is dirty. It is considered an error in the case of

  In this manner, the brightness and resolution when the adjustment sheet 40b is read by the CIS 21 can be adjusted so as to become the set brightness and resolution target values. As a result, it is not necessary to manually input the target values of brightness and resolution, and the time for manually inputting the target values can be eliminated. Image data obtained by reading the target values from the front surface of the document 3 and from the back surface. The read image data can be adjusted to have the same brightness and resolution.

  In the above-described embodiment, the black pattern 41 for position adjustment, the pattern 42 for brightness adjustment, and the pattern 43 for resolution adjustment are formed on one adjustment sheet 40b. Is used to read each pattern 41, 42, 43, but all patterns 41, 42, 43 may be read by one reading.

  Further, after adjusting the position using the first adjustment sheet on which the black pattern 41 is formed without using the single adjustment sheet 40b on which the patterns 41, 42, and 43 are formed, the brightness and darkness are adjusted. The second adjustment sheet on which the pattern 42 for adjusting the degree is read, the intensity is adjusted based on the target value for the intensity adjustment, and the pattern 43 for adjusting the resolution is formed. It is also possible to read the third adjustment sheet and adjust the resolution based on the resolution adjustment target value.

  In the above description, the digital multi-function peripheral has been described as an example of the image forming apparatus of the present invention. However, the present invention may be applied to a single device such as a color copier, a scanner, or a facsimile.

  Furthermore, in the above description, the adjustment sheet 40a for the CCD element and the adjustment sheet 40b for the CIS element are used, but a common adjustment sheet may be used.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1 is a block diagram of an image forming apparatus according to an embodiment of the present invention. It is side surface sectional drawing of the reading part shown in FIG. FIG. 4 is a diagram illustrating an example of an adjustment sheet for adjusting image formation by the image forming apparatus. 3 is a flowchart for explaining a back surface adjustment operation of the image forming apparatus according to the embodiment of the present invention, and particularly shows an operation of setting a target value. It is a flowchart for demonstrating the back surface adjustment operation | movement of the image forming apparatus in one Embodiment of this invention, and shows each adjustment process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reading part, 4 Paper feeding roller, 5 Separation roller, 6 Registration roller, 7 Conveyance path 10,20 Glass, 11 Reader, 17 CCD element, 21 CIS element, 26 Cover, 30 Image forming apparatus, 31 Control part, 32 Operation part, 33 EEPROM, 34 Display part, 35 Printing part, 36 Communication part, 40, 40a, 40b Adjustment sheet.

Claims (7)

First reading means for reading one side of the document;
Second reading means for reading the other side of the document;
The second reading means when the adjustment sheet for adjusting the hue is read by the first reading means, and the hue data of the read output is read by the second reading means. An image forming apparatus comprising: target value data setting means for setting as a target value for adjusting an output hue. A document table on which a document to be read by the first reading unit is placed;
An automatic document feeding mechanism that automatically feeds the document for reading one side of the document by the first reading unit and reading the other side of the document by the second reading unit;
When the adjustment sheet is placed on the document table and the adjustment value sheet is automatically fed by the automatic feeding mechanism, the target value data setting unit is configured to automatically feed the adjustment sheet with the hue data read by the first reading unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is set as a target value for adjusting a hue of a read output of the second reading unit. Fixed data storage means for storing predetermined fixed data for adjusting the hue;
Select which one of the hue data read by the first reading means and the predetermined fixed data stored in the fixed data storage means is set as the target value in the target value data setting means The image forming apparatus according to claim 1, further comprising a selection unit. The hue includes brightness and resolution,
4. The image forming apparatus according to claim 1, wherein a lightness / darkness pattern for adjusting the lightness / darkness and a resolution pattern for adjusting the resolution are formed on the adjustment sheet. 5. . A method for adjusting a hue of an image forming apparatus, wherein one side of a document is read by a first reading unit and the other side of the document is read by a second reading unit,
Reading an adjustment sheet for adjusting the hue of the second reading means output by the first reading means and setting the hue adjustment data of the read output as a target value;
Reading the adjustment sheet by the second reading unit, and adjusting the hue of the output of the second reading unit so that the color data of the read output becomes the hue data that is the target value. Method for adjusting hue of image forming apparatus. In the adjustment sheet, a position adjustment pattern, a brightness adjustment pattern for adjusting the hue, and a resolution adjustment pattern are formed,
Reading the position adjustment pattern by the first reading means to adjust the reading position of the second reading means;
The color adjustment method for an image forming apparatus according to claim 5, wherein after adjusting the reading position, the brightness and the resolution are adjusted as the color adjustment. The adjustment sheet includes a first adjustment sheet on which a position adjustment pattern is formed, and second and third adjustments on which a brightness adjustment pattern and a resolution adjustment pattern for adjusting the hue are formed, respectively. Including sheets for
Reading the position adjustment pattern from the first adjustment sheet by the first reading unit to adjust the reading position of the second reading unit;
After adjusting the reading position, the brightness adjustment pattern and the resolution adjustment pattern are sequentially read from the second and third adjustment sheets, and the brightness and the resolution are adjusted as the hue adjustment. Item 6. A method for adjusting a hue of an image forming apparatus according to Item 5.

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