JP2018006975A - Image reading device, image forming apparatus, and control program for image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device for appropriately correcting an image signal obtained by reading an image that is formed on a recording medium, relatively to a case where a reflection light that is reflected by a color reference part of a calibration part, is detected from start of movement of the calibration part to stop, an image forming apparatus and a control program for the image reading device.SOLUTION: An image sensor 200 comprises: a calibration part 230 including a color reference part that is narrower than an image formation region of a recording medium P; a movement part 250 for moving the calibration part 230 from an initial position to a stop position in a main scanning direction; and a CCD sensor 204 for detecting a reflection light that is reflected by the color reference part. The movement part 250 starts moving the calibration part 230 after the lapse of a first predetermined time from start of a reflection light detecting operation by the CCD sensor 204. The CCD sensor 204 finishes the reflection light detecting operation after the lapse of a second predetermined time from stop of the calibration part 230 by the movement part 250.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, and a control program for the image reading apparatus.

  Japanese Patent Laid-Open No. 2004-133826 discloses a variable speed conveyance device that conveys a document to an exposure area, a document sensor that detects insertion of the document into the conveyance device, a light source that exposes a document conveyed in the exposure area, and A one-dimensional photoelectric conversion element that reads an original image by scanning line by line and converts it into an electrical signal, and is located between the exposure area and the light source, and is movable in the main scanning line direction from one end to the other, and is uniformly white A shading correction plate having a narrow width and a driving mechanism for moving the shading correction plate, and the light source is activated when the document sensor detects insertion of the document, and after a predetermined time, the shading correction plate The movement is started, and the shading correction data is sequentially taken in by the one-dimensional photoelectric conversion element. It describes a shading correction apparatus characterized by controlling the document conveying speed by the conveying apparatus in a state that prevents entry into.

Japanese Patent Laid-Open No. 01-176158

  In the present invention, the image formed on the recording medium is compared with the case where the reflected light reflected by the color reference unit of the calibration unit is detected between the start and the stop of the movement of the calibration unit. An object of the present invention is to provide an image reading apparatus, an image forming apparatus, and an image reading apparatus control program capable of appropriately correcting the read image signal.

  In order to achieve the above object, the image reading apparatus according to claim 1 is characterized in that the main scanning direction is larger than the width in the main scanning direction intersecting the sub scanning direction of the image forming area of the recording medium conveyed in the sub scanning direction. A calibration unit having a color reference portion with a narrow width in the scanning direction, and an initial region in which the light is irradiated by the irradiation unit that irradiates light to the image forming region of the recording medium in the main scanning direction. A moving unit that moves from a position to a stop position; and a detecting unit that detects reflected light emitted from the irradiating unit and reflected by the color reference unit, wherein the detecting unit includes the reflected light. After the first predetermined time has elapsed since the start of the detection operation, the calibration unit starts moving from the initial position, and the detection unit detects that the movement unit has stopped the calibration unit at the stop position. After the second predetermined time has elapsed, the reflected light is detected. The operation is completed.

  According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the color reference portions are arranged side by side in the main scanning direction, and the width in each of the main scanning directions is the recording width. A first color reference portion and a second color reference portion that are narrower than the width of the image forming area of the medium in the main scanning direction;

  According to a third aspect of the present invention, in the image reading apparatus according to the second aspect, the color of the first color reference portion is one of an achromatic color and a chromatic color. The color is the other of the achromatic color and the chromatic color.

  In order to achieve the above object, an image forming apparatus according to claim 4 includes: an image forming unit that forms an image on a recording medium based on image information; and the recording medium formed by the image forming unit. The image reading apparatus according to any one of claims 1 to 3, wherein the image reading device is read.

  In order to achieve the above object, the control program of the image reading apparatus according to claim 5 is more than the width in the main scanning direction intersecting the sub scanning direction of the image forming area of the recording medium conveyed in the sub scanning direction. A calibration section having a color reference section having a narrow width in the main scanning direction; and an area irradiated with light from an irradiation section that irradiates the image forming area of the recording medium with light. A control program for an image reading apparatus, further comprising: a moving unit that moves from an initial position to a stop position; and a detection unit that detects reflected light emitted from the irradiation unit and reflected by the color reference unit. The computer controls the moving unit to start moving the calibration unit from the initial position after a first predetermined time has elapsed since the detecting unit started the detection operation of the reflected light, and the moving unit Is the calibration section The Stop the stop position after the second predetermined time is for executing a process of controlling the detecting unit so as to terminate the operation of detecting the reflected light.

  According to the first, fourth, and fifth aspects of the present invention, the reflected light reflected by the color reference unit of the calibration unit is detected after the calibration unit starts moving and stops. Compared with the case where it does, correction | amendment with respect to the image signal which read the image formed on the recording medium can be performed appropriately.

  According to the second aspect of the present invention, the image signal can be corrected more appropriately than in the case where there is one color reference portion.

  According to the third aspect of the present invention, in order to correct the unevenness in the brightness of the image indicated by the image signal more appropriately than in the case where the color of the color reference portion is either an achromatic color or a chromatic color. And information for correcting the color of the image can be obtained.

It is a fracture front view showing an example of composition of an image forming device of this embodiment. It is a schematic fracture front view which shows an example of a structure of the built-in image sensor of this embodiment. It is a perspective view which shows an example of a structure of the calibration part of this embodiment. It is a schematic block diagram which shows an example of a structure of the moving part of this embodiment. FIG. 2 is a block diagram illustrating an example of a configuration of a main part related to an electrical system in the image forming apparatus of the present embodiment. It is a block diagram which shows an example of a structure of the read signal processing part of this embodiment. It is a schematic diagram for demonstrating reading of the white reference plane and yellow reference plane in the built-in image sensor of this embodiment. It is a flowchart which shows an example of the flow of the calibration process with respect to the built-in image sensor of this embodiment. 9 is a flowchart illustrating an example of a flow of a shading correction profile creation process in the calibration process illustrated in FIG. 8. 9 is a flowchart illustrating an example of a flow of a color correction profile creation process in the calibration process illustrated in FIG. 8. It is a schematic diagram for demonstrating reading of the white reference plane and yellow reference plane in the built-in image sensor of this embodiment. It is a schematic diagram for demonstrating reading of the white reference plane and yellow reference plane in the built-in image sensor of this embodiment when a calibration part is provided only with the white reference plane. It is a schematic diagram for demonstrating reading of the white reference plane and yellow reference plane in the built-in image sensor of this embodiment.

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

  FIG. 1 is a diagram illustrating a schematic configuration of the image forming apparatus 10 of the present embodiment, and FIG. 2 is a diagram illustrating an example of a built-in image sensor 200 provided in the image forming apparatus 10 of the present embodiment.

  The image forming apparatus 10 of the present embodiment selectively forms a full-color image and a black and white image, and as shown in FIG. 1, a first housing 10A and a second housing connected to the first housing 10A. And a housing 10B. An image signal processing unit 13 that performs image processing on image data supplied from an external device such as a computer is provided on the upper portion of the second housing 10B. On the other hand, the first special color (V), the second special color (W), yellow (Y), magenta (M), cyan (C), and black (K) are provided on the upper portion of the first housing 10A. Toner cartridges 14V, 14W, 14Y, 14M, 14C, and 14K for containing toner are provided.

  Examples of the first special color and the second special color include colors (including transparency) other than yellow, magenta, cyan, and black. In the following description, the first special color (V), the second special color (W), yellow (Y), magenta (M), cyan (C), and black (K) are distinguished for each component. Is described with the symbols “V”, “W”, “Y”, “M”, “C”, “K” for distinguishing the individual, and the description of the above symbols is omitted when the individual is not distinguished To do.

  Below the toner cartridge 14, an image forming unit 16 corresponding to each color toner is provided corresponding to each toner cartridge 14.

  An exposure device 40 provided for each image forming unit 16 irradiates the image carrier 18 with a light beam L modulated from the image data received from the image signal processing unit 13 and subjected to image processing.

  Each image forming unit 16 includes an image carrier 18 that is rotationally driven in one direction. By irradiating each image carrier 18 with the light beam L from each exposure device 40, an electrostatic latent image is formed on each image carrier 18.

  Around each image carrier 18, a corona discharge (non-contact charging) charger that charges the image carrier 18, and an electrostatic latent image formed on the image carrier 18 by the exposure device 40 with toner. A developing device that develops, a blade that removes toner remaining on the image holding member 18 after transfer, and a static eliminator that irradiates the image holding member 18 after transfer with light to remove electricity. Note that the charger, the developing device, the blade, and the charge removal device are arranged in this order from the upstream side to the downstream side in the rotation direction of the image carrier 18 so as to face the surface of the image carrier 18.

  A transfer unit 32 is provided below each image forming unit 16. The transfer unit 32 includes an annular intermediate transfer belt 34 that is in contact with each image carrier 18 and a primary transfer roll 36 that multi-transfers the toner image formed on each image carrier 18 to the intermediate transfer belt 34. .

  The intermediate transfer belt 34 is wound around a driving roll 38 driven by a motor (not shown), a tension applying roll 41, an opposing roll 42, and a plurality of winding rolls 44. It is circularly moved in one direction (counterclockwise direction in FIG. 1).

  Each primary transfer roll 36 is disposed opposite to the image carrier 18 of each image forming unit 16 with the intermediate transfer belt 34 interposed therebetween. The primary transfer roll 36 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power supply unit (not shown).

  A removal device 46 that removes residual toner, paper dust, and the like on the intermediate transfer belt 34 is provided on the opposite side of the drive roll 38 across the intermediate transfer belt 34.

  Below the transfer unit 32, a plurality of recording medium storage units 48 that store the recording medium P, which is an example of a medium such as paper, are provided. A delivery roll 52 that feeds the recording medium P from each recording medium container 48 to the transport path 60 is provided above one end side (right side in front view in FIG. 1) of each recording medium container 48.

  A separation roll 56 that separates the recording media P one by one is provided on the downstream side in the recording medium conveyance direction of the delivery roll 52 (hereinafter sometimes simply referred to as “downstream side”). A plurality of transport rolls 54 that transport the recording medium P are provided on the downstream side of the separation roll 56.

  A conveyance path 60 provided between the recording medium accommodating unit 48 and the transfer unit 32 extends to a transfer position T between the secondary transfer roll 62 and the opposing roll 42.

  The secondary transfer roll 62 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power feeding unit (not shown). The secondary transfer roll 62 secondarily transfers the color toner images transferred onto the intermediate transfer belt 34 onto the recording medium P conveyed along the conveyance path 60.

  In addition, a preliminary path 66 extending from the side surface of the first housing 10 </ b> A is provided so as to join the transport path 60. The recording medium P sent out from another recording medium accommodation unit (not shown) arranged adjacent to the first housing 10 </ b> A can enter the conveyance path 60 through the spare path 66.

  On the downstream side of the transfer position T, a plurality of conveyance belts 70 that convey the recording medium P on which the toner image has been transferred toward the second casing 10B are provided in the first casing 10A. In addition, a transport belt 80 that transports the recording medium P transported by the transport belt 70 to the downstream side is provided in the second housing 10B.

  A fixing unit 82 for fixing the toner image transferred on the surface of the recording medium P to the recording medium P is provided on the downstream side of the conveying belt 80.

  The fixing unit 82 includes a fixing belt 84 and a pressure roll 88. Between the fixing belt 84 and the pressure roll 88, a fixing portion N that pressurizes and heats the recording medium P to fix the toner image is formed. The fixing belt 84 is wound around a driving roll 89 and a driven roll 90, and the fixing belt 84 is heated by a heating unit such as a halogen heater incorporated therein.

  As shown in FIG. 1, a cooling unit 110 that cools the recording medium P heated by the fixing unit 82 is provided on the downstream side of the fixing unit 82.

  The cooling unit 110 includes an absorption device 112 that absorbs heat of the recording medium P, and a pressing device 114 that presses the recording medium P against the absorption device 112. The absorption device 112 is disposed on one side (upper side in FIG. 1) with respect to the conveyance path 60, and the pressing device 114 is disposed on the other side (lower side in FIG. 1).

  On the downstream side of the cooling unit 110, there is provided a correction device 140 that conveys the recording medium P and corrects the curl of the recording medium P.

  A built-in image sensor 200 that detects toner density defects, image defects, image position defects, and the like of the toner image fixed on the recording medium P is provided on the downstream side of the correction device 140. Details of the built-in image sensor 200 will be described later.

  On the downstream side of the built-in image sensor 200, a discharge roll 198 that discharges the recording medium P on which an image is formed to a discharge unit 196 attached to the side surface of the second housing 10B is provided.

  When images are formed on both sides, the recording medium P sent from the built-in image sensor 200 is conveyed to a reversing path 194 provided on the downstream side of the built-in image sensor 200.

  The recording medium P transported along the reversing path 194 is transported toward the first housing 10A with the front and back being reversed, and further enters the transporting path 60 provided above the recording medium accommodating portion 48. It is sent again to the transfer position T.

  In the image forming apparatus 10 of the present embodiment, components for forming images of the first special color and the second special color (image forming units 16V and 16W, exposure devices 40V and 40W, toner cartridges 14V and 14W, and The primary transfer rolls 36 </ b> V and 36 </ b> W) are configured to be attachable to the first housing 10 </ b> A as additional parts according to the user's selection. Therefore, the image forming apparatus 10 does not have a component for forming an image of the first special color and the second special color, or any one of the first special color and the second special color. It is good also as a structure which has only the components for forming an image.

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

  The image data that has been subjected to image processing by the image signal processing unit 13 is sent to each exposure device 40. Each exposure device 40 emits each light beam L according to the image data, exposes each image carrier 18 charged by the charger, and forms an electrostatic latent image.

  The electrostatic latent image formed on the image carrier 18 is developed by the developing device, and the first special color (V), the second special color (W), yellow (Y), magenta (M), and cyan (C). A toner image of each color of black (K) is formed.

  As shown in FIG. 1, each color toner image formed on the image carrier 18 of each of the image forming units 16V, 16W, 16Y, 16M, 16C, and 16K is composed of six primary transfer rolls 36V, 36W, 36Y, and 36M. , 36C, and 36K, multiple transfer is sequentially performed on the intermediate transfer belt.

  The toner images of the respective colors that have been multiplex-transferred onto the intermediate transfer belt 34 are secondarily transferred onto the recording medium P conveyed from the recording medium accommodating portion 48 by the secondary transfer roll 62. The recording medium P onto which the toner image has been transferred is transported toward the fixing unit 82 provided inside the second housing 10B by the transport belt 70.

  The toner images of the respective colors on the recording medium P are fixed on the recording medium P by being heated and pressurized by the fixing unit 82. Further, the recording medium P on which the toner image is fixed is cooled by passing through the cooling unit 110 and then sent to the correction device 140 to correct the curvature generated in the recording medium P.

  The recording medium P whose curvature is corrected is discharged to the discharge unit 196 by the discharge roll 198 after an image defect or the like is detected by the built-in image sensor 200.

  Next, the built-in image sensor 200 will be described.

  In the following description, as shown in FIG. 2, the sub-scanning direction, which is the conveyance direction of the recording medium P, is the X direction, the height direction of the apparatus is the Y direction, the main scanning direction) and the depth direction of the apparatus is the Z direction. It corresponds.

  The built-in image sensor 200 of this embodiment is used for detecting whether or not there is an abnormality in the image formed on the recording medium P by the image forming unit 16, and the built-in image sensor 200 in this case is The image forming unit 16 has a function as a measurement unit of gradation reproducibility and color reproducibility. Further, in order to maintain the function as the measurement unit normally, calibration (calibration) of the built-in image sensor 200 is performed regularly or irregularly.

  As shown in FIG. 2, the built-in image sensor 200, which is an example of an image reading device, has an irradiation unit 202 that irradiates light toward a recording medium P on which an image is recorded, and a recording medium that is irradiated from the irradiation unit 202. An image forming unit 208 including an image forming optical system 206 that forms an image of reflected light reflected by P on a CCD (Charge Coupled Device) sensor 204 and a calibration unit 230 used for calibration are provided.

  The irradiation unit 202 irradiates light toward the recording medium P on which an image is recorded. The irradiation unit 202 is disposed on the upper side of the conveyance path 60 of the recording medium P, and a pair of first lamp 212A and second lamp 212B that are elongated in the Z direction (main scanning direction) (hereinafter, they are not distinguished from each other). The case is simply referred to as “lamp 212”). The lamp 212 is an example of an irradiation unit.

  In the present embodiment, a plurality of LEDs (Light Emitting Diodes) (not shown) arranged in the main scanning direction are used as the lamp 212, but the lamp 212 may be a fluorescent lamp or a xenon lamp.

  Further, the length of the irradiation range of the lamp 212 is larger than the width of the maximum recording medium P to be conveyed. The pair of lamps 212 are arranged symmetrically with respect to the optical axis OA (designed optical axis) that is reflected by the recording medium P and travels toward the image forming unit 208. More specifically, the pair of lamps 212 are arranged symmetrically with respect to the optical axis OA so that the irradiation angle to the recording medium P is, for example, 45 ° or more and 50 ° or less.

  Specifically, the pair of lamps 212 are arranged along the conveyance path 60 of the recording medium P, the first lamp 212 is arranged on the upstream side in the conveyance direction of the recording medium P, and the second lamp 212B is the recording medium. It arrange | positions in the downstream of the conveyance direction of P. The light irradiated from the first lamp 212A and the second lamp 212B is irradiated to the irradiation position D of the transparent window glass 286 on the transport path 60 between the first lamp 212A and the second lamp 212B.

  The imaging optical system 206 includes a first mirror 214 that reflects the light guided along the optical axis OA in the X direction (downstream in the conveyance direction of the recording medium P in the present embodiment), and the first mirror 214. The second mirror 216 that reflects the reflected light upward, the third mirror 218 that reflects the light reflected by the second mirror 216 to the upstream side in the transport direction of the recording medium P, and the light reflected by the third mirror 218 are CCD A lens 220 that focuses (images) the sensor 204 is configured as a main part. The CCD sensor 204 is an example of a detection unit.

  The CCD sensor 204 is arranged on the upstream side in the transport direction of the recording medium P with respect to the optical axis OA. The CCD sensor 204 in this embodiment includes a plurality of light receiving elements (for example, photodiodes) arranged along the main scanning direction, and includes a red image sensor, a green image sensor, and a blue image sensor. It is a sensor. Each color image sensor is provided with a filter that transmits light of each color component to the light receiving surface of the light receiving element. Each color image sensor outputs, as a signal, the electric charge accumulated according to the amount of each color component of the light received by the light receiving element.

  The length of the first mirror 214 in the main scanning direction (Z direction) is larger than the maximum width of the recording medium P. The first mirror 214, the second mirror 216, and the third mirror 218 condense (condensate) the reflected light of the recording medium P incident on the imaging optical system 206 in the main scanning direction (Z direction). While reflecting). Thereby, the reflected light from each part in the width direction of the recording medium P is made incident on the cylindrical lens 220.

  In the built-in image sensor 200, the CCD sensor 204 outputs a read signal corresponding to the imaged light, that is, the image density, to the control device 20 (see FIGS. 1 and 5) of the image forming apparatus 10. The control device 20 performs processing for correcting an image formed in the image forming unit 16 based on the read signal input from the built-in image sensor 200. As an example of the process of correcting the image performed by the control device 20, there is a correction of the intensity of irradiation light or the image formation position by the exposure device 40 based on a signal input from the built-in image sensor 200.

  In addition, a light amount diaphragm unit 224 (224L, 224S, 224U) is provided between the third mirror 218 and the lens 220 in the imaging optical system 206. The light amount diaphragm unit 224 narrows the amount of light that forms an image on the CCD sensor 204 across the optical path in the main scanning direction in the Y direction, and the amount of light amount is adjusted by an external operation. The amount of light reduced by the light amount diaphragm unit 224 is adjusted so that the amount of light focused on the CCD sensor 204 is equal to or greater than a predetermined amount even if the light emission amount of the lamp 212 changes with time.

  The window glass 286 transmits the light of the first lamp 212A and the second lamp 212B toward the recording medium P. In the window glass 286, an irradiation area irradiated with light from the lamp 212 is an area that overlaps an area through which an image forming area of the recording medium P conveyed on the conveyance path 60 passes, and an image is read by the CCD sensor 204. Read area. In the built-in image sensor 200 of the present embodiment, the length of the reading area in the main scanning direction is the maximum width of the image forming area in which an image can be formed on the recording medium P (hereinafter referred to as “width”). Longer than that).

  As shown in FIG. 3, the calibration unit 230 according to the present embodiment includes a white reference surface 232 and a yellow reference surface 234 provided on a holding member 237 having an L-shaped cross section attached to the holding member 236. ing. The width of each of the white reference surface 232 and the yellow reference surface 234 is narrower than the width of the image forming area.

  The white reference surface 232 is a reference surface for correcting lightness unevenness in the main scanning direction caused by the lamp 212 and the CCD sensor 204, that is, so-called shading correction. For example, a white film is attached to the holding member 237. . When the irradiation light from the lamp 212 is applied to the white reference surface 232, the reflected light reflected by the white reference surface 232 enters the CCD sensor 204 via the imaging optical system 206.

  The yellow reference plane 234 is a reference plane for correcting the color tone in the main scanning direction caused by the lamp 212 and the CCD sensor 204, specifically, chromaticity unevenness. For example, a yellow film is placed on the holding member 237. In addition, the white reference surface 232 is attached adjacent to the main scanning direction. When the irradiation light from the lamp 212 is applied to the yellow reference surface 234, the reflected light reflected by the yellow reference surface 234 is incident on the CCD sensor 204 via the imaging optical system 206. The reason why yellow is used as the color of the reference surface of the present embodiment is that the lamp 212 of the present embodiment includes a white LED including a blue LED chip and a yellow fluorescent material.

  That is, the white LED used in the lamp 212 of the present embodiment is formed by laminating a blue LED chip and a transparent resin containing a yellow fluorescent material. The yellow fluorescent material around the chip is excited by the blue light emitted from the blue LED chip to generate yellow fluorescence. Thereby, blue and yellow having complementary colors are added (synthesized) to generate white light. Therefore, for example, when manufacturing a white LED, when the blue LED chip has a variation in blue color, or a variation in the characteristics, addition amount, dispersion state, etc. of the yellow fluorescent material, the color temperature of the light generated by the white LED is This is because the direction may change in the yellow direction or the blue direction.

  In addition, white LED is not restricted to what combined said blue LED chip and yellow fluorescent substance, What combined LED chip and fluorescent substance of another color may be sufficient. In this case, the color of the reference surface may be changed according to the configuration of the white LED and the color of the LED chip or the fluorescent material.

  As illustrated in FIG. 4, the calibration unit 230 moves the lower part of the window glass 286 in the main scanning direction between the initial position and the stop position by the moving unit 250. In the built-in image sensor 200 of the present embodiment, the initial position corresponds to the back side of the built-in image sensor 200 in FIG. 2, and the stop position corresponds to the front side of the built-in image sensor 200 in FIG. In addition, in order to avoid complication, the movement part 250 is abbreviate | omitting illustration in FIG.

  The moving unit 250 of this embodiment includes a drive roll 252, a roll 253, a transmission belt 254, a shaft 256A, and a shaft 256B.

  The shaft 256 </ b> A and the shaft 256 </ b> B are supported by wall surfaces 258 at both ends so that the axial direction is along the main scanning direction.

  On the other hand, as shown in FIG. 3, the holding member 236 of the calibration unit 230 of the present embodiment is provided with a hole 236A and a hole 236B. The shaft 236A is provided in the hole 236A, and the shaft 256B is provided in the hole 236B. , Each is inserted.

  On the other hand, the drive roll 252 and the roll 253 are aligned in the main scanning direction and are rotatably attached to a wall surface (not shown). A transmission belt 254 is wound around the drive roll 252 and the roll 253. The top of the holding member 236 of the calibration unit 230 is fixed to the transmission belt 254.

  The drive roll 252 is driven to rotate by a motor (not shown). When the transmission belt 254 moves around in accordance with the rotation drive of the drive roll 252, the calibration unit 230 moves the shaft 256A and the shaft 256B. Along the main scanning direction.

  FIG. 5 is a block diagram showing a main configuration of the electrical system in the image forming apparatus 10 of the present embodiment.

  As described above, the control device 20 corrects the image formed in the image forming unit 16 based on the signal from the built-in image sensor 200. Further, the control device 20 controls calibration of the built-in image sensor 200 (for example, calibration of the above-described CCD sensor 204) via the control circuit 100.

  More specifically, as shown in FIG. 5, the control device 20 includes a CPU (Central Processing Unit) 20A, a ROM (Read Only Memory) 20B, a RAM (Random Access Memory) 20C, and an input / output port 20D. Yes. The CPU 20A, ROM 20B, and RAM 20C are connected to each other via a bus 20E such as an address bus, a data bus, and a control bus.

  The ROM 20B stores various programs including a control program 20F that is executed when the built-in image sensor 200 is calibrated. The CPU 20A develops and executes these programs in the RAM 20C, thereby performing various controls. Is called.

  A user interface (UI) panel 30, a lamp 212, a control circuit 100, and a read signal processing unit 350 are connected to the input / output port 20D. The UI panel 30 includes, for example, a touch panel display in which a transmissive touch panel is superimposed on a display. Various types of information are displayed on the display surface of the display, and information and instructions are given by a user touching the touch panel. Accepted. In the present embodiment, description is given by taking an example in which the UI panel 30 is applied. However, the present invention is not limited to this, and a display unit such as a liquid crystal display and an operation unit provided with a numeric keypad or operation buttons are separately provided. It is good also as a form provided in.

  As described above, the lamp 212 emits light for reading an image formed on the recording medium P by the built-in image sensor 200 or each color reference plane (white reference plane 232 and yellow reference plane 234). The controller 20 controls on / off (irradiation or non-irradiation of light).

  Further, the control circuit 100 controls the movement of the calibration unit 230 by controlling the driving of the driving roll 252 of the moving unit 250 based on an instruction from the control device 20.

  On the other hand, the read signal processing unit 350 performs various calibrations of the built-in image sensor 200 in accordance with instructions from the control device 20. In this embodiment, as calibration of the built-in image sensor 200, shading correction performed based on the shading correction profile created by reading the white reference plane 232, and color correction created by reading the yellow reference plane 234. Calibration relating to color correction in the main scanning direction, which is performed based on the image profile. In addition to the above, the calibration of the built-in image sensor 200 executed by the read signal processing unit 350 further performs, for example, calibration related to offset and gain correction for correcting the output upper and lower limit values of the CCD sensor 204. Also good.

  FIG. 6 shows an example of the configuration of the read signal processing unit 350. As shown in FIG. 6, the read signal processing unit 350 includes an S & H (sample and hold) unit 352, an amplification unit 354, an A / D (analog / digital) conversion unit 356, a shading correction unit 358, a color conversion unit 360, and A color correction unit 362 is provided.

The S & H unit 352 outputs a red (R) analog read signal S _R , a green (G) analog read signal S _G , and a blue (B) analog read signal S _B output from the CCD sensor 204. Is sampled and held for a certain period.

The amplifying unit 354 amplifies the read signals S _R , S _G , and S _B sampled and held by the S & H unit 352. Note that between the S & H unit 352 and the amplifying unit 354, the sampled read signals S _R , S _G , and S _{B with} respect to the black color of the read image (hereinafter also referred to as “read image”) may be used. In some cases, a black level adjustment circuit that performs correction processing so that the output level becomes a predetermined black level (zero level) may be provided.

The A / D conversion unit 356 converts the read signals S _R , S _G , and S _B that are analog signals amplified by the amplification unit 354 into digital signals, and converts the image data (R, G, B) that is digital signals. obtain.

  The shading correction unit 358 generates an image caused by the lamp 212 and the CCD sensor 204 based on the shading correction profile for the image data (R, G, B) converted into a digital signal by the A / D conversion unit 356. Is performed so that the white level of the read image coincides with the white level in image formation in the image forming unit 16. Further, when the built-in image sensor 200 is calibrated, the shading correction profile is created based on the read image obtained by reading the white reference plane 232.

The color conversion unit 360 uses the color conversion coefficient group (color conversion parameter) to convert the image data (R, G, B) in the RGB color space (device-dependent color space) to L ^* a ^* b which is a luminance color difference color space. ^* Convert into image data (L ^* , a ^* , b ^* ) in color space (device-independent color space).

The color correction unit 362 corrects the image data (L ^* , a ^* , b ^* ) in accordance with the chromaticity of the white LED of the lamp 212 based on the color correction profile, thereby adjusting the color in the main scanning direction. Correct. When the built-in image sensor 200 is calibrated, the color correction profile is created based on the read image obtained by reading the yellow reference plane 234.

In the image forming apparatus 10 of this embodiment, the image data (L ^* , a ^* , b ^* ) corrected by the color correction unit 362 is transferred to, for example, an image processing unit (not shown) connected to the input / output port 20D. Then, it is converted into image data (C, M, Y, K) in the CMYK color space (device-dependent color space) that is the output color space.

In the present embodiment, an example in which the L ^* a ^* b ^* color space is applied as the luminance color difference color space for converting the image data (R, G, B) has been described. However, the present invention is not limited to this. For example, a form in which a YCbCr color space, which is another luminance color difference color space, or the like is applied.

  Each of the above components constituting the read signal processing unit 350 of the present embodiment is controlled based on a control signal from the CPU 20A input via the input / output port 20D.

  Next, calibration of the built-in image sensor 200 of this embodiment will be described.

  In the image forming apparatus 10 according to the present embodiment, the built-in image using the calibration image 430 corresponding to the read signal obtained by reading the reflected light reflected by the white reference surface 232 and the yellow reference surface 234 by the CCD sensor 204. The sensor 200 is calibrated. Note that an image corresponding to the read signal obtained by reading the white reference surface 232 and the yellow reference surface 234 with the CCD sensor 204 is not actually formed on the recording medium P, but FIG. This is virtually shown as a calibration image 430. As an example, as shown in FIG. 7, the calibration image 430 includes a white image 432 corresponding to the white reference plane 232 and a yellow image 434 corresponding to the yellow reference plane 234.

  The size of the calibration image 430 is experimentally obtained in advance. Specifically, the length H2 in the sub-scanning direction of the white image 432 and the yellow image 434 in the calibration image 430 shown in FIG. 7 is the number of pixels necessary for creating the shading correction profile and the color correction profile. (Hereinafter, referred to as “the number of pixels for correction”).

  In the example illustrated in FIG. 7, the length H1 of the white image 432 and the yellow image 434 in the sub-scanning direction in the state positioned at the initial position, and the white image 432 and the yellow image 434 in the state positioned at the stop position. The length H3 in the sub-scanning direction is not less than the length corresponding to the number of correction pixels. In the present embodiment, the length H1 and the length H3 are equal to or longer than the length H2. Note that the length H1, the length H2, and the length H3 may be the same or different.

  In the image forming apparatus 10 of this embodiment, the CPU 20A of the control device 20 executes the control program 20F stored in the ROM 20B, thereby executing the calibration process of the built-in image sensor 200 shown in FIG.

  In step S100 of FIG. 8, the control device 20 causes the CCD sensor 204 to start a reading operation. The CCD sensor 204, which is a line sensor, reads line by line and outputs a read signal for one line in the main scanning direction of the calibration image 430. The control device 20 may turn on the lamp 212 prior to the execution of the calibration process, or may turn on the lamp 212 when the CCD sensor 204 starts reading.

  In the next step S104, the control device 20 determines whether or not a first predetermined time has elapsed. The first predetermined time is a time for obtaining the white image 432 and the yellow image 434 when the white reference surface 232 and the yellow reference surface 234 are located at the initial positions. Specifically, the length H1 and the CCD It is determined in advance according to the reading speed of the sensor 204 (reading speed in the sub-scanning direction).

  If the first predetermined time has not elapsed since the start of reading, a negative determination is made in step S104, and a standby state is entered. On the other hand, when the first predetermined time has elapsed since the reading was started, an affirmative determination is made in step S104, and the process proceeds to step S106.

  In step S <b> 106, the control device 20 causes the moving unit 250 of the built-in image sensor 200 to start moving the calibration unit 230 via the control circuit 100. The control device 20 of the present embodiment causes the moving unit 250 to move the calibration unit 230 from a predetermined initial position to a stop position. Here, as an example, as illustrated in FIG. 7, the control device 20 moves the calibration unit 230 in the order in which the white reference surface 232 is first and the yellow reference surface 234 is rearward.

  As an example, as shown in FIG. 7, in this embodiment, the position when the white reference surface 232 is at a position corresponding to the inside of the image forming area and the yellow reference surface 234 is at a position corresponding to the outside of the image forming area. Is the initial position. Further, in the present embodiment, a position where a part of the white reference surface 232 is located at a position corresponding to the outside of the image forming area and the yellow reference surface 234 is located at a position corresponding to the inside of the image forming area is set as the stop position.

  In the next step S108, the control device 20 determines whether or not the moving unit 250 has moved the calibration unit 230 to the stop position. If the calibration unit 230 has not moved to the stop position, a negative determination is made in step S108, and a standby state is entered. On the other hand, when the calibration unit 230 has moved to the stop position, an affirmative determination is made in step S108, and the process proceeds to step S110.

  In step S <b> 110, the control device 20 ends the movement of the calibration unit 230 by the moving unit 250 of the built-in image sensor 200 via the control circuit 100.

  In the next step S112, the control device 20 determines whether or not a second predetermined time has elapsed. The second predetermined time is a time for obtaining the white image 432 and the yellow image 434 when the white reference surface 232 and the yellow reference surface 234 are located at the stop position. Specifically, the length H3, the CCD It is determined in advance according to the reading speed of the sensor 204 (reading speed in the sub-scanning direction).

  If the second predetermined time has not elapsed since the movement of the calibration unit 230 has stopped, a negative determination is made in step S112, and a standby state is entered. On the other hand, when the second predetermined time has elapsed since the movement of the calibration unit 230 is stopped, an affirmative determination is made in step S112, and the process proceeds to step S114.

  In step S114, the control device 20 causes the CCD sensor 204 to end the reading operation.

  In the next step S116, the control device 20 causes the shading correction unit 358 to execute a shading correction profile creation process (see FIG. 9, details will be described later) to create a shading correction profile.

  In the next step S118, the control device 20 causes the color correction unit 362 to execute a color correction profile creation process (see FIG. 10, details will be described later) to create a color correction profile, and then performs this calibration process. Exit.

  In the present embodiment, the control device 20 moves the calibration unit 230 from the stop position to the initial position after the end of the calibration process.

  Next, the above-described shading correction profile creation processing will be described with reference to FIG. The shading correction profile created in this process corresponds to the illuminance profile in the main scanning direction in the calibration image 430.

  In step S200, the shading correction unit 358 assigns 0 to the variable x as an initial setting of the variable x indicating the coordinates in the main scanning direction. In the following, for convenience of explanation, the variable x is referred to as “coordinate x”.

  In the next step S202, the shading correction unit 358 counts the number of pixels of the white image 432 in the sub-scanning direction at the coordinate x of the calibration image 430.

  In the next step S204, the shading correction unit 358 determines whether or not the counted number of pixels is equal to or greater than the number of correction pixels. If the counted number of pixels is less than the number of correction pixels, a negative determination is made and the process proceeds to step S206.

  In step S206, the shading correction unit 358 associates 0 as the illuminance of the coordinate x, and then proceeds to step S210. In the example shown in FIG. 7, since the white image 432 is not formed in the calibration image 430 at a position corresponding to the initial position of the yellow reference plane 234, the number of pixels in the sub-scanning direction is greater than the number of correction pixels. Less. Therefore, the counted number of pixels is less than the number of correction pixels, and the value of the variable indicating the illuminance at the coordinate x is 0.

  On the other hand, in step S204, if the counted number of pixels is equal to or greater than the number of correction pixels, an affirmative determination is made, and the process proceeds to step S208. In step S208, the shading correction unit 358 derives the illuminance at the coordinate x based on the read signal. . The method for deriving the illuminance is not particularly limited, and a general-purpose method may be used. For example, the illuminance may be derived using the distance between the white reference surface 232 and the CCD sensor 204 and the illumination intensity.

  In the example shown in FIG. 7, the white image 432 in the image forming area has the length in the sub-scanning direction equal to the maximum value H when the error is ignored, so the number of pixels counted in step S204 is equal to or greater than the number of correction pixels. Therefore, the illuminance at the coordinate x is derived. In step S208, the derived illuminance is associated as the illuminance at coordinate x.

  In the next step S210, the shading correction unit 358 adds 1 to the value of the coordinate x.

  In the next step S212, the shading correction unit 358 determines whether or not the value of the coordinate x is equal to or larger than the width of the calibration image 430. That is, the shading correction unit 358 determines whether or not the illuminance at the coordinate x is derived from one end to the other end in the main scanning direction of the reading area. Here, when it becomes negative determination, it returns to step S202 and repeats the process of step S204-S210. On the other hand, if the determination is affirmative, the shading correction profile creation process is terminated.

  A profile representing the illuminance corresponding to each coordinate x derived in this manner is a shading correction profile. The created shading correction profile is stored in the shading correction unit 358, and is used when performing shading correction of an image signal obtained by reading an image formed on the recording medium P as described above.

  In order to move the white reference plane 232 and the yellow reference plane 234 in this way, as shown in FIG. 7 as an example, the white reference illuminance derivable area, which is the area of the coordinate x from which the illuminance is derived from the white image 432, is displayed. All formation regions are included. The white reference illuminance derivable area includes the position corresponding to the end of the calibration image 430 on the stop position side. On the other hand, the white reference illuminance derivable area that is the area of the coordinate x where the illuminance is 0 (illuminance cannot be derived) exists only on the initial position side, and the color reference illuminance nonderivable area is an image formation area. Is not included. Therefore, an appropriate shading correction profile corresponding to the image forming area is created.

  Next, the above-described color correction profile creation processing will be described with reference to FIG. Note that the color correction profile created in this processing corresponds to the chromaticity profile in the main scanning direction in the calibration image 430.

  The tint correction profile creation processing is the same as the shading correction profile creation processing (see FIG. 9) described above except that the chromaticity at the coordinate x is derived.

  Specifically, the processes of steps S300, S304, S210, and S312 of the color correction profile creation process shown in FIG. 10 are the processes of steps S200, S204, and S212 related to the shading correction profile creation process. Corresponds to each.

  On the other hand, the processing in step S302 of the color correction profile creation processing shown in FIG. 10 differs from step S202 related to the shading correction profile in that the number of pixels of the yellow image 434 is counted instead of the white image 432.

  That is, in step S302, the color correction unit 362 counts the number of pixels of the yellow image 434 in the sub-scanning direction at the coordinate x of the calibration image 430.

  Further, the processes in steps S306 and S308 of the color correction profile creation process shown in FIG. 10 differ from steps S206 and S208 related to the shading correction profile in that chromaticity is derived from the detected illuminance.

  In step S306, the color correction unit 362 associates 0 as the chromaticity of the coordinate x, and then proceeds to step S310. In the example shown in FIG. 7, since the yellow image 434 is not formed at the position corresponding to the stop position of the white reference surface 232 in the calibration image 430, the number of pixels in the sub-scanning direction is larger than the number of correction pixels. Less. Therefore, the counted number of pixels is less than the number of correction pixels, and the value of the variable indicating the illuminance at the coordinate x is 0.

  In step S308, the chromaticity of the coordinate x is derived based on the color correction unit 362 and the read signal. The method for deriving chromaticity is not particularly limited, and a general-purpose method may be used. For example, the chromaticity may be derived using the color matching function, the spectral distribution, and the wavelength of light.

  In the example shown in FIG. 7, the yellow image 434 in the image forming area has the length in the sub-scanning direction equal to the maximum value H if the error is ignored, so the number of pixels counted in step S304 is equal to or greater than the number of correction pixels. Therefore, the chromaticity of the coordinate x is derived. In step S308, the derived chromaticity is associated as the chromaticity of the coordinate x.

  Since the white reference plane 232 and the yellow reference plane 234 are moved as described above, as shown in FIG. 7 as an example, a yellow reference chromaticity derivable area that is an area of the coordinate x from which the illuminance is derived from the yellow image 434, The image forming area is deviated, and the yellow reference chromaticity derivable area includes only a part of the image forming area. For this reason, in this embodiment, the chromaticity at the end of the image forming area on the stop position side is not derived from the calibration image 430.

  A profile representing the chromaticity corresponding to each coordinate x derived in this manner is a color correction profile. The created color correction profile is stored in the color correction unit 362 and is used when correcting the color of an image signal obtained by reading an image formed on the recording medium P as described above. It is done.

  Regardless of the present embodiment, a color correction profile that complements the chromaticity at the end of the image forming area on the stop position side may be created. As a method for complementing the chromaticity, for example, before shipment of the image forming apparatus 10, the chromaticity at the end of the image forming area on the stop position side based on a yellow reference plane having a width equal to or larger than the width of the reading area May be derived and stored in advance, and a method of using the chromaticity for complementation may be applied. Further, for example, a method may be applied in which the chromaticity of the end portion on the stop position side of the image forming region and the end portion on the initial position side of the image forming region that is symmetric in the main scanning direction are used for interpolation.

  As described above, according to the built-in image sensor 200 of the present embodiment, the shading correction profile used by the shading correction unit 358 of the read signal processing unit 350 to perform shading correction on the image signal can be created. The color correction profile used by the color correction unit 362 to correct the color of the image signal can be created.

  In the present embodiment, as described above, the white reference illuminance derivable area includes the entire image forming area, and the yellow reference chromaticity derivable area includes a part of the image forming area. It becomes higher than the accuracy of taste correction.

  In the tint correction profile creation process shown in FIG. 10, the case of creating a tint correction profile for correcting the chromaticity for the tint has been described. However, in the case of correcting the chroma for the tint, Deriving saturation instead of chromaticity and creating a profile related to saturation.

  Note that the initial position and stop position when the moving unit 250 moves the calibration unit 230 may be opposite to the case where the position in the main scanning direction is shown in FIG. 7, as shown in FIG.

  Also in this case, as shown in FIG. 11, the white reference illuminance derivable area where the illuminance can be derived from the white image 432 includes all image forming areas, and the white reference illuminance derivable area where the illuminance is 0 is included. Does not include an image forming area. Therefore, an appropriate shading correction profile corresponding to the image forming area is created. Thus, when performing calibration, the direction of the main scanning direction in which the moving unit 250 moves the calibration unit 230 is not particularly limited.

  As described above, the built-in image sensor 200 of the image forming apparatus 10 according to the present embodiment has a width in the main scanning direction that intersects the sub scanning direction of the image forming area of the recording medium P conveyed in the sub scanning direction. A calibration unit 230 having a color reference portion with a narrow width in the main scanning direction and a calibration unit 230 are arranged such that the region irradiated with light by the lamp 212 that irradiates the image forming region of the recording medium P in the main scanning direction. , A moving unit 250 that moves from the initial position to the stop position, and a CCD sensor 204 that detects reflected light emitted from the lamp 212 and reflected by the color reference unit. The moving unit 250 reflects the CCD sensor 204. After the first predetermined time has elapsed since the start of the light detection operation, the calibration unit 230 starts to move from the initial position, and the CCD sensor 204 Moving portion 250 after a second predetermined time has elapsed from the stop of the calibration unit 230 at the stop position, and ends the operation of detecting the reflected light.

  With this configuration, as shown in FIG. 7 and the like, in the calibration image 430, the number of pixels (length) in the sub-scanning direction of the white image 432 and the yellow image 434 at the initial position and the stop position is corrected. More than the number of pixels.

  Therefore, according to the built-in image sensor 200 of the present embodiment, the light is reflected by the white reference surface 232 and the yellow reference surface 234 of the calibration unit 230 from the start to the stop of the movement of the calibration unit 230. Compared with the case where the reflected light is detected, it is possible to appropriately correct the image signal obtained by reading the image formed on the recording medium P.

  In the above-described embodiment, the color reference portion includes the white reference surface 232 and the yellow reference surface 234, one of which is the first color reference portion and the other is the second color reference portion. It is possible to obtain information for generating a shading correction profile and information for generating a color correction profile for correcting color.

  In the above embodiment, since the widths of the white reference surface 232 and the yellow reference surface 234 are narrower than the widths of the image forming region and the reading region, the white reference surface having a width larger than that of the image forming region and the reading region and yellow The apparatus can be reduced in size compared with the case where the reference surface is provided.

  In the above embodiment, the case where the calibration unit 230 includes the white reference surface 232 and the yellow reference surface 234 has been described. However, the calibration unit 230 can detect only one of the white reference surface 232 and the yellow reference surface 234. You may have. When either one is provided, for example, when the calibration unit 230 includes only the white reference surface 232, the entire reading region can be set as a white reference illuminance derivable region as in the example illustrated in FIG.

  Further, the arrangement order of the white reference surface 232 and the yellow reference surface 234 in the main scanning direction may be the reverse of the above embodiments. In this case, as in the example illustrated in FIG. 13, the relationship between the white reference illuminance derivable region by the white reference surface 232 and the yellow reference chromaticity derivable region by the yellow reference surface 234 is opposite to the case illustrated in FIG. 7. become. That is, as in the example shown in FIG. 13, the white reference illuminance derivable area includes a part of the image forming area, and the yellow reference chromaticity derivable area includes all of the image forming area. It becomes higher than the accuracy of shading correction.

  As described above, in the read signal processing unit 350, after the shading correction by the shading correction unit 358, the color correction by the color correction unit 362 is performed. Therefore, by increasing the accuracy of shading correction, the accuracy of color correction also increases, so it is preferable to give priority to the accuracy of shading correction.

  Further, in each of the above embodiments, the mode in which the control device 20 controls the moving unit 250 via the control circuit 100 has been described. However, the present invention is not limited thereto, and the control circuit 100 may directly control the moving unit 250. . Further, in each of the above embodiments, the mode in which the control device 20 controls the read signal processing unit 350 has been described. However, the present invention is not limited thereto, and the control circuit 100 may control the read signal processing unit 350.

  In each of the above embodiments, the case where the white reference surface 232 in which the color of the reference surface for shading correction is white and the yellow reference surface 234 in which the color of the reference surface for color correction is yellow is used has been described. However, the color of the reference surface for each correction is not limited to this. The color of the reference surface for shading correction may be an achromatic color. In addition, the color of the reference surface for color correction may be a chromatic color.

  Further, the widths of the reading area and the image forming area are not limited to the forms exemplified in the above embodiments. The reading area may include the entire image forming area. For example, the reading area and the image forming area may have substantially the same width. Further, in each of the embodiments described above, the form in which the reading area and the movement range are the same has been described, but the relationship between the reading area and the movement range is not limited to the form. For example, the width of the reading area may be narrower than the movement range.

  In addition, this embodiment is an example of this invention, and it cannot be overemphasized that it can change according to a condition within the range which does not deviate from the main point of this invention.

10 Image forming apparatus 20 Control apparatus 20A CPU
20F control program 100 control circuit 200 built-in image sensor 204 CCD sensor 212 lamp 230 calibration unit 232 white reference plane 234 yellow reference plane 250 moving unit 350 read signal processing unit 358 shading correction unit 362 color correction unit 430 calibration image 432 white Image 434 Yellow image

Claims (5)

A calibration unit having a color reference portion whose width in the main scanning direction is narrower than the width in the main scanning direction intersecting the sub scanning direction of the image forming area of the recording medium conveyed in the sub scanning direction;
A moving unit that moves the calibration unit from the initial scanning position to the stop position in the main scanning direction in a region irradiated with light from the irradiation unit that emits light to the image forming region of the recording medium;
A detection unit that detects reflected light emitted from the irradiation unit and reflected by the color reference unit;
The moving unit starts moving the calibration unit from the initial position after a first predetermined time has elapsed since the detection unit started the reflected light detection operation.
The detection unit ends the reflected light detection operation after a second predetermined time has elapsed since the moving unit stopped the calibration unit at the stop position.
Image reading device. The color reference portions are arranged side by side in the main scanning direction, and a width of each of the main scanning directions is smaller than a width of the image forming region of the recording medium in the main scanning direction and Having a two-color reference part,
The image reading apparatus according to claim 1. The color of the first color reference part is one of an achromatic color and a chromatic color, and the color of the second color reference part is the other color of the achromatic color and the chromatic color.
The image reading apparatus according to claim 2. An image forming unit that forms an image on a recording medium based on the image information;
The image reading apparatus according to any one of claims 1 to 3, wherein an image on the recording medium formed by the image forming unit is read.
An image forming apparatus. A calibration unit having a color reference portion whose width in the main scanning direction is narrower than the width in the main scanning direction intersecting the sub scanning direction of the image forming area of the recording medium conveyed in the sub scanning direction;
A moving unit that moves the calibration unit from the initial scanning position to the stop position in the main scanning direction in a region irradiated with light from the irradiation unit that emits light to the image forming region of the recording medium;
A detection unit that detects reflected light emitted from the irradiation unit and reflected by the color reference unit;
A control program for an image reading apparatus comprising:
On the computer,
Controlling the moving unit to start moving the calibration unit from the initial position after a first predetermined time has elapsed since the detection unit started the detection operation of the reflected light;
A process of controlling the detection unit so as to end the detection operation of the reflected light after a second predetermined time has elapsed since the moving unit stopped the calibration unit at the stop position;
A control program for an image reading apparatus.