JP5888058B2 - Imaging apparatus, colorimetric apparatus, colorimetric system, and image forming apparatus - Google Patents

Description

  The present invention relates to an imaging apparatus, a colorimetric apparatus, a colorimetric system, and an image forming apparatus, and more particularly to an imaging apparatus, a colorimetric apparatus, a colorimetric system, and an image forming apparatus that stably image a subject and a reference chart.

  Image forming apparatuses such as color ink jet type image forming apparatuses and color electrophotographic image forming apparatuses are offset by advertising media and pamphlets that require a high image but a relatively small number of copies as the image quality improves. It is also used for printing.

  In offset printing that requires high image quality, the color of the printed matter requested by the customer may differ from the color of the print output result that is actually printed out by the image forming apparatus.

  Usually, the customer confirms the color of the printed matter on the display and places an order for printing. However, each image forming apparatus has a color reproduction characteristic specific to each model, which is different from the color confirmed on the display. May result in printing.

  Therefore, conventionally, a technique for performing color reproduction using a color space that does not depend on a device such as a display or an image forming apparatus, such as a Lab color space or an xyz color space, has been used.

  The image forming apparatus controls the amount of color material and the like in order to output a specified color. For example, in an ink jet image forming apparatus, the output color is controlled by controlling the amount of ink discharged from the ink head by calculating and controlling the amount of ink discharged and the print pattern. In the image forming apparatus, the output color is controlled by controlling the amount of toner adhering to the photosensitive member, the amount of laser beam, and the like.

  However, the amount of the color material, for example, the ink discharge amount of the ink jet image forming apparatus varies depending on the state of the nozzle of the head, the viscosity of the ink, the variation of the discharge drive elements (piezo elements, etc.), Variation in color reproducibility occurs. Further, the ink ejection amount of the ink jet type image forming apparatus changes with time in one image forming apparatus or varies for each image forming apparatus. In other words, variations in the color reproduction of the image occur.

  Therefore, conventionally, in an image forming apparatus, color adjustment processing is performed in order to suppress output variations due to characteristics unique to the device and to improve output reproducibility with respect to input. In this color adjustment processing, for example, first, an image of a reference color patch (reference color patch image) is actually output by the image forming apparatus, and the reference color patch image is measured by the color measurement device. Then, a color conversion parameter is generated based on the difference between the colorimetric value of the reference color patch image measured by the colorimetry device and the colorimetric value of the corresponding reference color in the standard color space, and the color conversion parameter is Set in the image forming apparatus. After that, when outputting an image according to the input image data, the image forming apparatus performs color conversion on the input image data based on the set color conversion parameter, and after color conversion is performed. By recording and outputting an image based on the image data, an output of an image with high color reproducibility can be achieved by suppressing output variations due to characteristics unique to the device.

  In this conventional color adjustment processing, a spectral colorimeter is widely used as a color measuring device for measuring a reference color patch image, and the spectral colorimeter can obtain a spectral reflectance for each wavelength. Therefore, highly accurate colorimetry can be performed. However, since the spectrocolorimeter is an expensive device equipped with a large number of sensors, it is desired to perform highly accurate color measurement using a cheaper device.

  Conventionally, reference colorimetric means for measuring a reference color chart in advance in order to obtain color reference values as RGB data, and an object including the reference color chart and a color-measurement object are imaged simultaneously or separately. Color image input means for obtaining data, image extraction means for extracting RGB data of the reference color chart and RGB data of the color to be measured from RGB data obtained by the color image input means, and the image extraction means The difference between the RGB data of the reference color chart obtained in step 1 and the RGB data of the reference color chart obtained by the reference color measurement means is obtained, and at least the RGB data of the color to be measured is corrected using this difference. There has been proposed a colorimetric device characterized by comprising a calculation means (see Patent Document 1). In this conventional technique, a reference color chart to be compared with the subject is placed near the subject to be colorimetric, and the subject and the reference color chart are simultaneously imaged by a color video camera as a color image input means. In addition, it is disclosed that the RGB data of the subject is corrected using the RGB data of the reference color chart obtained by imaging, and the RGB data of the subject is converted into color values in the standard color space.

  However, in the prior art described in the above publication, it is difficult to keep the positional relationship between the reference color chart to be imaged as a subject to be compared and the color image input means constant, and the imaging conditions vary with each imaging. Therefore, there is a problem that it is difficult to perform stable imaging.

  Accordingly, an object of the present invention is to capture an image of a subject and a reference chart with a stable positional relationship.

In order to achieve the above object, the imaging apparatus according to claim 1 is a predetermined box-shaped frame body in which an opening for imaging the subject is formed on an opposing surface portion facing the subject, and the opening. an illumination light source for illuminating the parts, and over said opening of said frame body, movable in the aligned standby position and the opening for opening the opening deviates from the opening on, before Symbol illumination source A shutter member provided with a reference chart for providing a predetermined color reference on the surface on the irradiation side, and a surface on the sensor means side of the opposed surface portion, provided at the standby position of the shutter member, A second reference chart for providing a color reference, reflected light from the subject facing the opening in a state where the shutter member is positioned at the standby position , and the shutter member being positioned on the opening Said reference char in state Characterized in that it comprises a sensor means for imaging the said subject and said reference chart and the second reference chart by receiving the reflected light from the second reference chart with.

  According to the present invention, the subject and the reference chart can always be imaged with a stable positional relationship.

1 is a schematic perspective view of an image forming apparatus to which an embodiment of the present invention is applied. The top view of a carriage part. FIG. The top view of an imaging part. AA arrow sectional drawing of the imaging device of FIG. 4 in the state which the shutter has opened the opening part. AA arrow sectional drawing of the imaging device of FIG. 4 in the state which the shutter has closed the opening part. BB arrow sectional drawing of the imaging part of FIG. CC sectional view of the imaging part of FIG. FIG. 3 is a block diagram of a main part of the image forming apparatus. The block block diagram of an imaging part and a colorimetry control part. Explanatory drawing of the acquisition process of the reference | standard colorimetry value and imaging reference RGB value from a reference | standard sheet, and a reference value linear transformation matrix acquisition process. The figure which shows an example of an initial reference RGB value. Explanatory drawing of a colorimetry process. Explanatory drawing of the linear conversion matrix production | generation process between reference values RGB. The figure which shows the relationship between an initial reference | standard RGB value and the reference | standard RGB value at the time of colorimetry. Explanatory drawing of a basic colorimetry process. FIG. 17 is a diagram showing basic colorimetry processing continued from FIG. 16. The flowchart which shows the imaging process by a simple imaging system. The flowchart which shows the imaging process by a sequential imaging system. FIG. 3 is a plan view of an imaging unit with a rotating shutter in an open state. FIG. 3 is a plan view of an imaging unit in a state where a rotating shutter is closed. FIG. 6 is a top cross-sectional view of an imaging unit with a rotating shutter in an open state. FIG. 6 is a top cross-sectional view of an imaging unit with a rotating shutter in a closed state. The front sectional view of the image pick-up part in the state where the shutter of the rotation method is opened. FIG. 3 is a front cross-sectional view of the imaging unit with a rotating shutter. FIG. 7 is a top cross-sectional view of another imaging unit in a state where the rotating shutter is open. FIG. 7 is a top cross-sectional view of another imaging unit in a state where the rotating shutter is closed. The front sectional view of the other image pick-up part in the state where the shutter of the rotation system is opened. The front sectional view of the other image pick-up part in the state where the shutter of the rotation system is closed. The top view of an imaging part provided with two reference charts. FIG. 31 is a cross-sectional view taken along the line AA of the imaging unit in FIG. 30 with the shutter open. FIG. 31 is a cross-sectional view taken along the line AA of the imaging unit in FIG. 30 with the shutter closed. 1 is a system configuration diagram of an image forming system.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 33 are diagrams illustrating an embodiment of an imaging apparatus, a colorimetric apparatus, a colorimetric system, and an image forming apparatus according to the present invention. FIG. 1 is a schematic perspective view of an image forming apparatus 1 to which an embodiment of a system and an image forming apparatus is applied.

  In FIG. 1, an image forming apparatus 1 has a main body housing 2 disposed on a main body frame 3, and a main guide rod in the main scanning direction indicated by a double arrow A in FIG. 4 and the auxiliary guide rod 5 are stretched over. The main guide rod 4 movably supports the carriage 6, and the carriage 6 is provided with a connecting piece 6 a that engages with the sub guide rod 5 to stabilize the posture of the carriage 6.

  In the image forming apparatus 1, an endless belt-like timing belt 7 is disposed along a main guide rod 4, and the timing belt 7 is stretched between a driving pulley 8 and a driven pulley 9. The driving pulley 8 is rotationally driven by the main scanning motor 10, and the driven pulley 8 is disposed in a state in which a predetermined tension is applied to the timing belt 7. The driving pulley 8 is rotationally driven by the main scanning motor 10 to rotate and move the timing belt 7 in the main scanning direction according to the rotation direction.

  The carriage 6 is connected to a timing belt 7, and is reciprocated in the main scanning direction along the main guide rod 4 when the timing belt 7 is rotationally moved in the main scanning direction by the drive pulley 8.

  The image forming apparatus 1 houses a cartridge unit 11 and a maintenance mechanism unit 12 at both end positions in the main scanning direction in the main body housing 2, and the cartridge unit 11 includes yellow (Y), magenta (M), and cyan. (C) and the cartridge which each accommodates each ink of black (K) is accommodated so that replacement | exchange is possible. Each cartridge of the cartridge unit 11 is connected to recording heads 20y, 20m, 20c, and 20k (see FIG. 2) of the corresponding color of the recording head 20 mounted on the carriage 6 by pipes (not shown), and from the cartridges through the pipes. Ink is supplied to the recording heads 20y, 20m, 20c, and 20k. In the following description, the recording heads 20y, 20m, 20c, and 20k are collectively referred to as the recording head 20.

  As will be described later, the image forming apparatus 1 moves on the platen 14 (see FIG. 2) in the sub-scanning direction (arrow B direction in FIG. 1) perpendicular to the main scanning direction while moving the carriage 6 in the main scanning direction. By ejecting ink onto the recording medium P that is intermittently conveyed, an image is recorded on the recording medium P.

  That is, the image forming apparatus 1 of the present embodiment intermittently conveys the recording medium P in the sub-scanning direction, and moves the carriage 6 in the main scanning direction while the conveyance of the recording medium P in the sub-scanning direction is stopped. While moving, ink is ejected from the nozzle array of the recording head 20 mounted on the carriage 6 onto the recording medium P on the platen 14 to form an image on the recording medium P.

  The maintenance mechanism unit 11 performs cleaning of the ejection surface of the recording head 20, capping, ejection of unnecessary ink, and the like to discharge unnecessary ink from the recording head 20 and maintain the reliability of the recording head 20. Yes.

  The image forming apparatus 1 is provided with a cover 13 that can open and close the conveyance part of the recording medium P. When the image forming apparatus 1 is maintained or when a jam occurs, the cover 13 is opened so that the inside of the main body housing 2 can be opened. Maintenance work, removal of the jam recording medium P, and the like can be performed.

  As shown in FIG. 2, the carriage 6 is mounted with recording heads 20y, 20m, 20c, and 20k. The recording heads 20y, 20m, 20c, and 20k are piped to the cartridges of the corresponding colors of the cartridge unit 11, respectively. Are connected to each other, and inks of corresponding colors are ejected onto the opposing recording medium P. That is, the recording head 20y is yellow (Y) ink, the recording head 20m is magenta (M) ink, the recording head 20c is cyan (C) ink, and the recording head 20k is black (K) ink. Discharge each.

  The recording head 20 is mounted on the carriage 6 so that its discharge surface (nozzle surface) faces downward (recording medium P side) in FIG. 1, and discharges ink onto the recording medium P.

  In the image forming apparatus 1, an encoder sheet 15 is disposed in parallel with the timing belt 7, that is, the main guide rod 5, over at least the movement range of the carriage 6. The encoder 6 reads the encoder sheet 15 on the carriage 6. A sensor 21 is attached. The image forming apparatus 1 controls the movement of the carriage 6 in the main scanning direction by controlling the driving of the main scanning motor 10 based on the reading result of the encoder sheet 15 by the encoder sensor 21.

  As shown in FIG. 3, the recording head 20 mounted on the carriage 6 includes recording nozzles 20 y, 20 m, 20 c, and 20 k configured by a plurality of nozzle rows, and is recorded on the platen 14. An image is formed on the recording medium P by ejecting ink from the nozzle rows onto the medium P. In the image forming apparatus 1, the upstream recording head 20 and the downstream recording head 20 are mounted on the carriage 6 in order to ensure a wide width of an image that can be formed on the recording medium P by one scan of the carriage 6. ing. In addition, the recording head 20k that discharges black ink has twice the number of recording heads 20y, 6m, and 6c that discharge color ink mounted on the carriage 6 in order to improve the black printing speed. Further, the recording heads 20y and 6m are arranged adjacent to each other in the main scanning direction so that the colors overlap in the reciprocating operation of the carriage 6 and the color does not change between the forward path and the backward path. Therefore, the arrangement of the recording heads 20y, 20m, 20c, and 20k of the recording head 20 is not limited to the arrangement shown in FIG.

  As shown in FIG. 2, an imaging unit (imaging device) 30 is attached to the carriage 6, and the imaging unit 30 performs colorimetry on a subject (colorimetric object) during color adjustment processing described later. Shoot the subject.

  As shown in FIGS. 4 to 8, in the imaging unit 30, a rectangular box-shaped frame body 32 whose surface on the substrate 31 side is open is fixed to the substrate 31 by a fastening member 33. Is fixed to the carriage 6 shown in FIG.

  In the imaging unit 30, the frame 32 has a lower surface of a surface portion (hereinafter referred to as a bottom surface portion) 32 a opposite to the substrate 31 facing the recording medium P on the platen 14 with a predetermined distance d. In the state, it is attached to the carriage 6, and the bottom surface portion (opposing surface portion) 32 a has a substantially rectangular opening 32 b on one side in the main scanning direction (the direction indicated by the arrow A in FIGS. 4 to 6). Is formed.

  The imaging unit 30 is a surface on the frame 32 side of the substrate 31, and an image sensor unit 34 is disposed at a position facing the center of the opening 32 b, and the image sensor unit (sensor means) 34 includes: A two-dimensional image sensor 35 such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor and a lens 36 are provided. The lens 36 collects reflected light (at least diffused reflected light) from the imaging target and a reference chart KC described later on the sensor surface of the two-dimensional image sensor 35. The two-dimensional image sensor 35 images the imaging target and the reference chart KC by photoelectrically converting the reflected light from the imaging target and the reference chart KC collected on the sensor surface by the lens 36.

  The imaging unit 30 preferably has a small gap d in consideration of the focal length with respect to the two-dimensional image sensor 35, as will be described later. Is set to a size that does not contact the lower surface of the recording medium P with the recording medium P, for example, about 1 mm to 2 mm.

  As will be described later, the opening 32b includes a reference color patch KP (see FIG. 11) and a colorimetric adjustment sheet CS (see FIG. 11) of the reference sheet KS (see FIG. 11) that is an imaging target (subject) formed on the recording medium P. This is used to image the colorimetric adjustment color patch CP (see FIG. 13) of FIG. The opening 32b may be at least large enough to capture all images (patch images) to be imaged. However, since there is a gap d between the frame 32 and the object to be imaged, there is a gap around the opening 32b. In consideration of the generated shadow, it is formed in an opening state slightly larger than the size of the imaging region to be imaged. Therefore, the center of the opening 32 b is located at a position opposite to the image sensor 34, that is, on the optical axis of the image sensor 34.

  The imaging unit 30 is provided with an illumination light source 37 on each of the substrates 31 at the center position in the main scanning direction of the opening 32b and at both ends in the sub scanning direction. The illumination light source 37 is an LED (Light Emitting Diode). Etc. are used. The illumination light source 37 uniformly illuminates the imaging target on the recording medium P through a reference chart KC and an opening 32b described later. That is, the illumination light source 37 is disposed at a target position in the sub-scanning direction with the image sensor unit 34 as the center, and as will be described later, the reference chart KC and the opening 32b moving on the opening 32b. The imaging target on the recording medium P is disposed at a position where the illumination light is uniformly irradiated. The arrangement position of the illumination light source 37 is not limited to the above arrangement position, and the illumination light is uniformly applied to the subject on the recording medium P through the reference chart KC and the opening 32b that have moved to the opening 32b. Any appropriate position may be used.

  The imaging unit 30 has a shutter (shutter member) on the bottom surface 32a opposite to the opening 32b in the main scanning direction so as to be movable in the main scanning direction on the bottom surface 32a as shown in FIGS. ) 38 is disposed, and the shutter 38 has such a size that both end surfaces in the sub-scanning direction can be moved while being guided by the inner wall surface of the frame 32 in the sub-scanning direction, as shown in FIG. In addition, the surface treatment is performed in such a manner that both end faces in the sub-scanning direction can move while smoothly contacting the inner wall surface of the frame body 32. The shutter 38 has a shape that is slightly larger than the size of the opening 32b.

  In addition, the imaging unit 30 is provided with guide members 39 on both inner wall surfaces in the sub-scanning direction of the frame body 32 so that the shutter 38 can move between the bottom surface portion 32a and prevent the shutter 38 from floating. The guide member 39 is formed in a state of projecting a predetermined amount from the inner wall surface of the frame body 32 in the sub-scanning direction in the center direction of the sub-scanning direction in parallel with the bottom surface portion 32a. A guide groove 39a for guiding the movement of the shutter 38 in the main scanning direction is formed therebetween.

  The shutter 38 is made of, for example, a thermoplastic resin with t = 1 (ABS resin: acrylonitrile, butadiene, styrene copolymer), and at least the position of the opening 32b. When moving to the end face of the guide groove 39a on the opening 32b side, the opening 32b is blocked and mist such as paper powder or ink powder is prevented from entering the frame 32 from the opening 32b. To do.

  The image forming apparatus 1 normally discharges ink droplets toward the recording medium P from the nozzle holes formed on the nozzle surfaces of the recording heads 20y, 20m, 20c, and 20k of the carriage 6 to the recording medium P. And the subject such as the reference color patch KP and the colorimetric adjustment color patch CP are formed. At this time, the image forming apparatus 1 continuously forms an image by ejecting a plurality of ink droplets from the nozzle holes, and the continuously ejected ink droplets coalesce during flight, and eventually one ink droplet. However, the ink droplets flying from behind the combined ink droplets become small ink droplets called satellites without being combined. The small ink droplets called satellites coalesce and adhere to the recording medium P and begin to float off the flight trajectory of the ink droplets that form an image, becoming mist.

  As shown in FIGS. 5 to 8, the imaging unit 30 has a pair of compression springs (biasing means) 40 fixed to the side end surface of the shutter 38 opposite to the opening 32 b side in the main scanning direction. The other end of the compression spring 40 is fixed to the inner wall surface on the opposite side of the opening 32b in the main scanning direction.

  Accordingly, the shutter 38 is constantly urged by the compression spring 40 in the direction of the opening 32b with a predetermined urging force.

  Furthermore, as shown in FIGS. 5 to 8, the imaging unit 30 has a pair of thin flat plates 41 fixed to the side end surface on the opening 32 b side of the shutter 38 in the main scanning direction. The other end of the frame 32 is wound around a winding roller 43 that is attached to the outer surface of the frame 32 in the main scanning direction opposite to the opening 32b via a cover 42.

  The take-up roller 43 is connected to a rotating shaft of a pulley 44, and the pulley 44 is connected to a pulley 46 by a belt 45. The pulley 46 is fixed to a rotating shaft of a winding motor 47 fixed to the side surface of the frame body 32. When the pulley 46 is rotationally driven by the winding motor 47, the pulley 44 rotates via the belt 45. Then, the winding roller 43 rotates in the same direction.

  When the take-up roller 43 rotates in the clockwise direction, the imaging unit 30 winds the thin flat plate 41, draws the shutter 38 from the opening 32b, and opens the opening 32b.

  When the take-up roller 43 rotates counterclockwise, the imaging unit 30 releases the thin flat plate 41 and the urging force of the compression spring 40 moves the shutter 38 in the direction of the opening 32b, and the shutter 38 opens the opening 32b. Block it. That is, the compression spring 40, the thin flat plate 41, the cover 42, the take-up roller 43, the pulley 44, the belt 45, the pulley 46, and the take-up motor 47 as a whole close the shutter 38 that is a cover member and the opening 32b. It functions as a shutter opening / closing section (moving means) 48 that moves between a closed position (imaging position) and an open position (standby position) that opens the opening 32b. Further, the shutter 38 is movable in parallel to the imaging position on the opening 32b and the standby position on the bottom surface 32a that is off the opening 32b along the bottom surface 32a in the frame 32. The opening / closing unit 48 includes a compression spring (biasing means) 40 that biases the shutter 38 at the standby position in the imaging position direction, and a thin flat plate 41 that moves the shutter 38 in the standby position direction against the biasing force of the compression spring 40. , A cover 42, a take-up roller 43, a pulley 44, a belt 45, a pulley 46, and a movement drive unit (movement drive means) 49 including a take-up motor 47.

And as shown in FIG. 4, the imaging part 30 is on the upper surface of the shutter 38 (surface on the substrate 31 side).
A reference chart KC is detachably attached, and the reference chart KC is a plurality of reference color patch rows Pa to Pd for colorimetry, a dot diameter measurement pattern row Pe, and distance measurement, like a reference sheet KS described later. A line lk and a chart position specifying marker mk are formed.

  The color measurement patch rows Pa to Pd include a patch row Pa in which YMC primary color patches are arranged in gradation order, a patch row Pa in which RGB secondary color patches are arranged in gradation order, and a gray color. There are a patch array (achromatic gradation pattern) Pc in which patches of a scale are arranged in order of gradation, and a patch array Pd in which patches of a tertiary color are arranged, and the dot diameter measurement pattern array Pe has a size. It is a pattern sequence for measuring a geometric shape in which different circular patterns are arranged in order of size.

  The distance measurement line lk is formed as a rectangular frame surrounding the color measurement patch rows Pa to Pd and the dot diameter measurement pattern row Pe. The chart position specifying markers mk are provided at the positions of the four corners of the distance measuring line lk, and are markers for specifying each patch position.

  A colorimetric control unit 106 (see FIGS. 9 and 10), which will be described later, specifies the distance measurement line lk and the chart position specifying markers mk at the four corners from the image data of the reference chart KC acquired from the imaging unit 30. The position of the reference chart KC and the position of each pattern are specified.

  Each patch constituting the reference color patch rows Pa to Pd for colorimetry uses the spectroscope BS (see FIG. 11) as in the reference patch KP of the reference chart KC described later, and the Lab color which is a standard color space. A colorimetric value (Lab value) in the space is measured in advance, and becomes a reference value when measuring a colorimetric adjustment color patch CP of a colorimetric adjustment sheet CS described later.

  Note that the configuration of the color measurement patch rows Pa to Pd arranged in the reference chart KC is not limited to the arrangement example shown in FIG. 4, and any patch row can be used. As long as possible, a patch capable of specifying a wide color range may be used, and the YMCK primary color patch row Pa and the gray scale patch row Pc may be used for the ink used in the image forming apparatus 1. It may be composed of patches of colorimetric values. In addition, the RGB secondary color patch row Pa of the reference chart KC may be composed of patches of colorimetric values that can be developed with ink used in the image forming apparatus 1, and further, colorimetrics such as JapanColor. A reference color chart having a predetermined value may be used.

  The reference chart KC is used as a reference by the imaging unit 30 as a comparison target with the reference color patch KP of the reference sheet KS and the imaged colorimetric value of the colorimetric adjustment color patch CP of the colorimetric adjustment sheet CS that is the image pickup target in the color adjustment process. Photographed together with the color patch KP and the colorimetric adjustment color patch CP. That is, the imaging unit 30 includes the reference color patch KP of the reference sheet KS and the colorimetric adjustment color patch of the colorimetry adjustment sheet CS that are located outside the frame 32 through the opening 32b formed on the bottom surface 32a of the frame 32. Along with the imaging of the CP, the color patch on the reference chart KC attached to the upper surface of the shutter 38 moving to the position of the opening 32b is imaged as a comparison target.

  Note that the imaging unit 30 scans pixels sequentially and reads an image, so strictly speaking, the reference color patch KP of the reference sheet KS and the colorimetric adjustment patch CP of the colorimetric adjustment sheet CS and the reference are strictly speaking. Although the chart KC is not read at the same time, the image of the reference color patch KP, the color measurement adjustment patch CP, and the reference chart KC is acquired within one frame.

  The imaging unit 30 drives the take-up motor 47 under the control of a CPU 101 (see FIG. 9), which will be described later, at least during normal image formation and formation of the color measurement adjustment color patch CP of the color measurement adjustment sheet CS. Is released or rotated counterclockwise (see FIGS. 5 and 6), and the compression spring 40 moves the shutter 38 to a position (hereinafter, appropriately referred to as a standby position) where the shutter 32 is closed (covered). Therefore, it is possible to prevent the mist from entering the frame 32 by an image forming operation or the like, and the components (the reference chart KC, the image sensor unit 34, etc.) in the frame 32 from being contaminated by the mist.

  The imaging unit 30 is under the control of the CPU 101 (see FIG. 9) and the like at least when the imaging timing of the reference color patch KP and the colorimetric adjustment color patch CP (hereinafter referred to as a subject as appropriate) outside the frame 32 is reached. Then, the take-up motor 47 is driven to rotate the take-up roller 43 in the clockwise direction, the thin plate 41 is taken up by the take-up roller 43 against the urging force of the compression spring 40, and the shutter 38 is opened to the opening 32b. Is moved to a position where it is opened (hereinafter referred to as a standby position as appropriate) to open (release) the opening 32b.

  Therefore, the imaging unit 30 prevents the mist and the like from adhering to the reference chart KC and the image sensor unit 34 by the shutter 38, and raises the subject such as the color measurement adjustment sheet CS outside the reference chart KC and the frame 32. Imaging can be performed with high accuracy, and colorimetric processing can be performed with high accuracy.

  The image forming apparatus 1 of the present embodiment is configured as a block as shown in FIG. 9, and includes a central processing unit (CPU) 101, a read only memory (ROM) 102, a random access memory (RAM) 103, and main scanning. A driver 104, a recording head driver 105, a colorimetric control unit 106, a paper conveying unit 107, a sub-scanning driver 108, and the like are provided, and the recording head 20, the encoder sensor 21, and the imaging device mounted on the carriage 6 as described above. Part 30 and the like.

  The ROM 102 stores programs such as a basic program and a color adjustment processing program as the image forming apparatus 1 and necessary system data. The CPU 101 uses the RAM 103 as a work memory based on the program in the ROM 102, and performs image processing. The respective units of the forming apparatus 1 are controlled to execute basic processing as the image forming apparatus 1 and, at the same time, the colorimetric processing obtained by the colorimetric processing by the colorimetric control unit 106 based on the RGB values captured by the imaging unit 30. Based on the color value, color adjustment processing at the time of image formation is executed.

  In the control of the carriage 6 and the paper transport unit 107, the CPU 101 controls the driving of the main scanning driver 104 based on the encoder value from the encoder sensor 21, and controls the movement of the carriage 6 in the main scanning direction. The CPU 101 controls driving of a paper transport unit 107 such as a sub-scan motor and a transport roller (not shown) via a sub-scan driver 108. Further, the CPU 101 controls the ink ejection timing and the ink ejection amount by the recording head 20 via the recording head driver 105. In addition, the CPU 101 controls the lighting drive of the illumination light source 37 of the imaging unit 30 via the color measurement control unit 106.

  As described above, the imaging unit 30 generates a colorimetric value for color adjustment that accurately reproduces the color of image data when recording and outputting an image to a color intended by the user, as will be described later. The color measurement adjustment patch CP formed by the recording head 20 on the recording medium P is imaged at the time of color measurement, and the captured RGB values are output to the CPU 101.

  The imaging unit 30 and the colorimetric control unit 106 are configured as a block as shown in FIG. The imaging unit 30 includes the illumination light source 37, the image sensor unit 34, and the shutter opening / closing unit 48, and also includes an image processing unit 110, an interface unit 111, and the like. The image processing unit 110 includes an A / D conversion unit. 112, a shading correction unit 113, a white balance correction unit 114, a γ correction unit 115, and an image format conversion unit 116.

  The imaging unit 30 outputs analog RGB image data obtained by imaging the subject and the reference chart KC by the image sensor unit 34 to the image processing unit 110, and the image processing unit 110 receives the analog RGB image sent from the image sensor unit 34. Necessary image processing is performed on the image data and output to the colorimetric control unit 106.

  The A / D conversion unit 112 of the image processing unit 110 digitally converts analog RGB image data input from the image sensor unit 34 and outputs the converted data to the shading correction unit 113.

  The shading correction unit 113 corrects the error of the image data caused by the illuminance unevenness of the illumination light from the illumination light source 37 with respect to the imaging range of the image sensor unit 34 with respect to the RGB image data input from the A / D conversion unit 112. And output to the white balance correction unit 114.

  The white balance correction unit 114 corrects the white balance of the RGB image data after the shading correction, and outputs the corrected data to the γ correction unit 115.

  The γ correction unit 115 corrects the image data input from the white balance correction unit 114 so as to compensate for the linearity of the sensitivity of the image sensor unit 34 and outputs the corrected data to the image format conversion unit 116.

  The image format conversion unit 116 converts the image data after γ correction into an arbitrary format, and outputs it to the colorimetry control unit 106 via the interface unit 111.

  The interface unit 111 is used for the imaging unit 30 to acquire various setting signals, timing signals, and light source drive signals sent from the colorimetry control unit 106, and to send image data from the imaging unit 30 to the colorimetry control unit 106. Interface.

  The color measurement control unit 106 includes a frame memory 121, a timing signal generation unit 122, a light source drive control unit 123, a calculation unit 124, a nonvolatile memory 125, and a shutter opening / closing control unit 130. The calculation unit 124 includes color measurement values. A calculation unit 126 is provided.

  The frame memory 121 is a memory that temporarily stores the image data sent from the imaging unit 30, and outputs the stored image data to the calculation unit 124.

  As shown in FIG. 11, the non-volatile memory 125 includes Lab values that are colorimetric values of the colorimetric results of a plurality of reference color patches KP arrayed on the reference sheet KS by the spectroscope (colorimetry device) BS. And at least one of the XYZ values (both Lab and XYZ values in FIG. 11) are stored as reference colorimetric values in the memory table Tb1 of the nonvolatile memory 125 in correspondence with the patch numbers.

  Further, the image forming apparatus 1 stores the reference sheet KS of the image forming apparatus 1 in a state where the reference colorimetric values are stored in the nonvolatile memory 125 in the memory table Tb1 and in the initial state of the image forming apparatus 1. An imaging reference RGB value obtained by reading the same reference patch KP as that read by the spectroscope BS of the reference sheet KS by the imaging unit 30 by controlling the movement of the carriage 6 by being set on the platen 14 is stored in the nonvolatile memory 125. Is stored in the memory table Tb1 in correspondence with the patch number, that is, in correspondence with the reference colorimetric value, and each patch of the reference chart KC of the imaging unit 30 is imaged to obtain the RGB value. The RGB value of each patch in the chart KC is set as the initial reference RGB value RdGdBd, and the memory table of the nonvolatile memory 125 is controlled under the control of the calculation unit 124. It is stored in Le Tb1.

  When the image forming apparatus 1 stores the reference colorimetric value, the imaging reference RGB value, and the initial reference RGB value RdGdBd in the nonvolatile memory 125, the colorimetric value calculation unit 126 stores the reference colorimetry stored in the nonvolatile memory 125. A reference value linear conversion matrix for mutual conversion is calculated for a pair of XYZ values and imaging reference RGB values, that is, a pair of XYZ values and imaging reference RGB values of the same patch number, and the calculated reference value linear The conversion matrix is stored in the nonvolatile memory 125.

  In the image forming apparatus 1, the above processing is executed in the initial state of the image forming apparatus 1, and the reference colorimetric values, imaging reference RGB values, and initial reference RGB values RdGdBd as execution results are stored in the memory table Tb 1 of the nonvolatile memory 125. Then, a reference value linear transformation matrix is calculated and stored in the nonvolatile memory 125.

  Further, as will be described later, the image forming apparatus 1 according to the present exemplary embodiment includes a color measurement adjustment color patch CP and a frame as a subject formed on the recording medium P by the recording head 20 that changes with time during color adjustment processing. The reference chart KC disposed inside the body 32 is simultaneously imaged by the image sensor unit 34, and image data including the colorimetric adjustment color patch CP and the reference chart KC is output to the colorimetry control unit 106. The color measurement control unit 106 uses the color measurement adjustment color patch CP captured by the image sensor unit 34 during the color adjustment processing acquired from the imaging unit 30 as a reference color patch (hereinafter referred to as an initial reference color patch) of the reference sheet KS. After being read by the imaging unit 30 and converted into the initial reference RGB value RdGdBd of the patch Pa of the reference chart KC read and stored, the linearity of the colorimetric adjustment patch CP is changed with respect to the initial reference RGB value RdGdBd. A colorimetric process for obtaining a colorimetric value by taking out a portion having the same and performing linear conversion is performed.

  That is, the arithmetic unit 124 controls the operation of the colorimetric control unit 106, and the colorimetric value calculation unit 126 executes the colorimetric processing and outputs the colorimetric values that are the results of the colorimetric processing to the CPU 101. Then, the CPU 101 performs color adjustment processing on the image data using the colorimetric value, and controls the recording head 20 based on the color adjustment processed image data, thereby forming an image with improved color reproducibility. To do.

  The shutter opening / closing control unit (movement control unit) 130 releases or counteracts driving of the winding motor 47 of the shutter opening / closing unit 48 at least during normal image formation and formation of the color measurement adjustment color patch CP of the color measurement adjustment sheet CS. By rotating in the clockwise direction (see FIGS. 5 and 6), the shutter 38 is moved by the compression spring 40 to the closed position that covers (covers) the opening 32b, and the optical path length changing member 41 is misted by an image forming operation or the like. To prevent it from getting dirty. Further, the shutter opening / closing control unit 130 drives the winding motor 47 to rotate the winding roller 43 in the clockwise direction at least when the imaging timing of the reference color patch KP outside the frame 32 and the colorimetric adjustment color patch CP (subject) is reached. The thin plate 41 is wound up by the take-up roller 43 against the urging force of the compression spring 40, the shutter 38 is moved to the standby position where the opening 32b is opened, and the opening 32b is opened. To do. In the image forming apparatus 1 of the present embodiment, the shutter opening / closing control unit 130 is provided in the color measurement control unit 106, but may be provided in the imaging unit 30, or may be performed by the CPU 101 or the like. .

  The image forming apparatus 1 of this embodiment includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), and a CD-RW (Compact Disc Rewritable). A color measurement program for executing the color measurement method of this embodiment recorded on a computer-readable recording medium such as a DVD (Digital Versatile Disk), an SD (Secure Digital) card, or an MO (Magneto-Optical Disc). It is constructed as an image forming apparatus 1 equipped with a color measuring device that executes a color measuring method that realizes color reproducibility described later at low cost and stably by reading and introducing it into the ROM 102 or the nonvolatile memory 125 or the like. . This color measurement program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  Next, the operation of this embodiment will be described. The image forming apparatus 1 according to the present exemplary embodiment executes an imaging apparatus and a color measurement method that can stably and inexpensively realize color reproducibility.

  As shown in FIG. 11, the image forming apparatus 1 according to the present embodiment uses the spectroscope BS to calculate the color measurement results of a plurality of reference color patches arranged and formed on the reference sheet KS, among Lab values and XYZ values. , At least one of them is stored as a reference colorimetric value corresponding to the patch number in the memory table Tb1 of the nonvolatile memory 125.

  Further, when the image forming apparatus 1 is in a state where the reference colorimetric values are stored in the nonvolatile memory 125 in the memory table Tb1 and the image forming apparatus 1 is in an initial state due to manufacture, overfall, or the like, The reference sheet KS is set on the platen 14 of the image forming apparatus 1, the movement of the carriage 6 is controlled, and the same reference patch read by the spectroscope BS of the reference sheet KS is read by the imaging unit 30, and the frame The shutter 38 disposed inside the body 32 is moved to a closed position where the opening 32b is closed, and each patch (initial reference color patch) of the reference chart KC is imaged. The imaging of the patches Pa to Pd of the reference chart KC will be described later.

  When the image forming apparatus 1 captures the reference patch of the reference sheet KS and each patch of the reference chart KC by the imaging unit 30, the image forming apparatus 1 has RGB values obtained by processing the image data obtained by capturing the reference patch of the reference sheet KS by the image processing unit 110. As shown in FIG. 11, the calculation unit 124 of the colorimetry control unit 106 associates the imaging reference RGB value, that is, the device-dependent signal depending on the device, with the patch number in the memory table Tb1 of the nonvolatile memory 125. That is, the initial reference RGB value RdGdBd, which is the RGB value obtained by reading the initial reference color patch of the reference chart KC and processing it by the image processing unit 110 while storing it in correspondence with the reference colorimetric value, is shown in FIG. As shown in FIG.

  Note that the calculation unit 124 calculates an average value for each predetermined region (color measurement target region) in the image data of the initial reference color batch of the reference chart KC read by the imaging unit 30, and sets the average value as the initial reference RGB value RdGdBd. Yes. When the initial reference RGB value RdGdBd is calculated by averaging a large number of pixels in the colorimetric object region in this way, the influence of noise can be reduced and the bit resolution can be improved. FIG. 12B is a scatter diagram in which the initial reference RGB value RdGdBd is plotted. FIG. 12A is a reference Lab value Lddbdd and XYZ values obtained by converting the initial reference RGB value RdGdBd into Lab values. The reference XYZ value xdydzd also indicates a state registered in the nonvolatile memory 125.

  When the image forming apparatus 1 stores the reference colorimetric value, the imaging reference RGB value, and the initial reference RGB value RdGdBd in the nonvolatile memory 125, the colorimetric value calculation unit 126 of the calculation unit 124 is stored in the nonvolatile memory 125. Calculate a reference value linear conversion matrix for mutual conversion with respect to a pair of XYZ value and imaging reference RGB value of the reference colorimetric value, that is, a pair of XYZ value and imaging reference RGB value of the same patch number The reference value linear transformation matrix is stored in the nonvolatile memory 125.

  In this state, in the image forming apparatus 1, the CPU 101 performs main scanning movement control of the carriage 6, transport control of the recording medium P by the paper transport unit, and the recording head 20 based on image data input from the outside, print settings, and the like. And controlling the ink ejection from the recording heads 20y, 20m, 20c, and 20k of the recording head 20 while intermittently transporting the recording medium P, and recording and outputting an image on the recording medium P. .

  At this time, the amount of ink discharged from the recording heads 20y, 20m, 20c, and 20k may change depending on the characteristics unique to the device, changes with time, and the like. An image is formed with a color different from the color, and the color reproducibility deteriorates.

  Therefore, the image forming apparatus 1 executes color adjustment processing for obtaining a colorimetric value and performing color adjustment based on the colorimetric value at a predetermined color adjustment processing timing.

  That is, at the timing of color adjustment processing, the image forming apparatus 1 forms a plurality of color patches (color measurement adjustment color patches) CP on the recording medium P by the recording head 20 as shown in FIG. Recorded and output as a sheet CS. In this color measurement adjustment sheet CS, a plurality of color measurement adjustment color patches CP, which are color patches for color measurement adjustment, are formed and output by the recording head 20, and output at the color adjustment processing timing of the image forming apparatus 1. A colorimetric adjustment color patch CP reflecting the characteristics, particularly the output characteristics of the recording head 20 is formed. Note that the color patch data of the color measurement adjustment color patch CP is stored in advance in the nonvolatile memory 125 or the like.

  Then, as will be described later, the image forming apparatus 1 uses the RGB values obtained by imaging the plurality of color measurement adjustment color patches CP of the color measurement adjustment sheet CS as color measurement target RGB values (color measurement RGB values). A color object RGB value is converted into an initial reference RGB value RdGdBd, and among the reference colorimetric values registered in the memory table Tb1 of the nonvolatile memory 125, the initial reference RGB value RdGdBd is converted. A reference colorimetric value close to the distance (neighboring reference colorimetry value) is selected, and a colorimetric value for converting the colorimetric target RGB value into the selected neighborhood reference colorimetric value is obtained. Based on the colorimetric value Based on the image data after the color conversion, the recording head 20 outputs an image, thereby improving the color reproducibility of the image formed by the image forming apparatus 1.

  Therefore, as shown in FIG. 13, the image forming apparatus 1 sets the colorimetric adjustment sheet CS on the platen 14 or does not eject the colorimetric adjustment sheet CS when it is recorded. As the held state, the plurality of color measurement adjustment color patches CP of the color measurement adjustment sheet CS on the platen 14 are imaged by the imaging unit 30 while controlling the movement of the carriage 6, and the imaging unit 30 captures the reference chart KC. Capture the patch.

  The image forming apparatus 1 captures a colorimetric adjustment color patch CP of the colorimetry adjustment sheet CS and a patch of the reference chart KC by a predetermined amount, such as for each patch, or the colorimetry as will be described later. When all the colorimetric adjustment color patches CP of the adjustment sheet CS and all the patches Pa to Pd of the reference chart KC are imaged in order, the image processing unit 110 of the imaging unit 30 performs the colorimetry adjustment color patches of the colorimetry adjustment sheet CS. After performing necessary image processing on the image data of the CP and the image data of the patch of the reference chart KC, the image data (RGB values) of the color measurement adjustment color patch CP of the color measurement adjustment sheet CS are converted into the color measurement target RGB. Value, that is, a device-dependent signal that depends on the device, and the image data (RGB value) of the patch of the reference chart KC is used as a colorimetric reference RGB value RdsGdsBds Feed to the colorimetric control unit 106, the color measurement control unit 106, as shown in FIG. 13, stored temporarily in the frame memory 121 (step S11).

  The colorimetric control unit 106 uses the colorimetric value RGB value stored in the frame memory 121 by the colorimetric value calculation unit 126 of the calculation unit 124 to initialize the colorimetric object to be initialized using a reference RGB linear conversion matrix to be described later. Conversion into RGB values RsGsBs (steps S12 and S13).

  The calculation unit 124 of the color measurement control unit 106 executes the basic color measurement process described later by using the converted initialization color measurement target RGB value RsGsBs as the color measurement target RGB value (step S14), and converts the Lab color measurement value. Obtain (step S15).

  In the image forming apparatus 1 according to the present exemplary embodiment, the colorimetric value calculation unit 126 of the calculation unit 124 obtains the reference RGB linear conversion matrix as illustrated in FIGS. 14 and 15.

  That is, as shown in FIG. 14, the calorimetric value calculation unit 126 of the calculation unit 124 captures the patch of the reference chart KC when the imaging unit 30 captures the reference color patch KP of the reference sheet KS at the initial stage. In addition, when the initial reference RGB value RdGdBd stored in the nonvolatile memory 125 and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS are imaged by the imaging unit 30 during color measurement, the patch of the reference chart KC is also imaged. Then, the colorimetric reference RGB value RdsGdsBds stored in the nonvolatile memory 125 is read from the nonvolatile memory 125, and the colorimetric reference RGB value RdsGdsBds is converted into the initial reference RGB value RdGdBd. , And the obtained reference RGB linear conversion matrix is stored in the nonvolatile memory 125.

  That is, in FIG. 15, the points indicated by white dots in FIG. 15A are points where the initial reference RGB values RdGdBd are plotted in the rgb space, and the fill points are the colorimetric reference RGB values RdsGdsBds as rgb. This is a point plotted in space. As can be seen from FIG. 15A, the value of the colorimetric reference RGB value RdsGdsBds fluctuates from the value of the initial reference RGB value RdGdBd, and the fluctuation direction in the rgb space is shown in FIG. 15B. As indicated by the arrows, the directions are generally the same, but the direction of deviation differs depending on the hue. As described above, the reason why the RGB values fluctuate even when the patches of the same reference chart KC are imaged includes a change with time of the illumination light source 37 and a change with time of the two-dimensional image sensor 35.

  As described above, the colorimetric values are obtained using the colorimetric RGB values obtained when the colorimetric adjustment patch CP of the colorimetry adjustment sheet CS is imaged in a state where the patches of the same reference chart KC are fluctuated. If it is obtained, there is a risk that an error will occur in the colorimetric value by the amount of variation.

  In view of this, the image forming apparatus 1 according to the present embodiment uses the estimation method such as the least square method between the initial reference RGB value RdGdBd and the colorimetric reference RGB value RdsGdsBds as an initial value for the colorimetric reference RGB value RdsGdsBds. A reference RGB linear conversion matrix to be converted into the reference RGB value RdGdBd is obtained, and the colorimetric adjustment color patch CP of the colorimetric adjustment sheet CS is imaged by the imaging unit 30 using the reference RGB linear conversion matrix, and the nonvolatile memory is obtained. The colorimetric object RGB values stored in 125 are converted into initialization colorimetry object RGB values RsGsBs, and the converted initial colorimetry object RGB values RsGsBs are used as the colorimetry object RGB values, which will be described later. The process is executed to acquire the Lab colorimetric value.

  This linear conversion matrix between RGB may be not only a first-order but also a higher-order nonlinear matrix. If the nonlinearity is high between the rgb space and the XYZ space, a higher-order matrix can be obtained. , Conversion accuracy can be improved.

  The image pickup unit 30 is formed on the bottom surface portion 32a by moving the shutter 38 to the standby position and the reference color patch KP of the reference sheet KS as the subject and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS. A patch of the reference sheet KS attached to the shutter 38 by opening the opening 32b and taking an image through the opening 32b and moving the shutter 38 to the opening 32b, that is, to the closed position (imaging position). By imaging Pa to Pd, the patches Pa to Pd of the reference sheet KS, the reference color patch KP of the reference sheet KS as the subject, and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS are always in the same positional relationship. Can be imaged and can be imaged in a stable state.

  Further, in the imaging unit 30, the illumination light that irradiates the imaging surface of the recording medium P through the opening 32b and the illumination light that irradiates the reference chart KC are illumination light from the same illumination light source 37 and have the same illumination conditions. With this, it is possible to image the reference chart KC and the imaging surface of the recording medium P.

  Further, since the image capturing unit 30 has the same positional relationship with respect to the image sensor unit 34 as the arrangement condition of the aperture 32b of the image capturing region and the reference chart KC, color adjustment of the two-dimensional image sensor 35 using the reference chart KC. The accuracy of processing and colorimetric processing can be improved.

  Then, when the image forming apparatus 1 obtains the initial colorimetric target RGB value RsGsBs as described above and sets it as the colorimetric target RGB value, the memory table Tb1 of the nonvolatile memory 125 as shown in FIGS. Of the colorimetric values registered in the colorimetric object RGB values, the reference colorimetric values (neighboring reference colorimetric values) that are close in distance to the colorimetric values converted into the colorimetric object RGB values are selected and measured. A basic colorimetry process for obtaining a colorimetric value for converting a color target RGB value to a selected neighborhood reference colorimetric value is executed, and recording is performed based on image data after color conversion is performed based on the colorimetric value. By outputting an image by the head 20, the color reproducibility of the image formed by the image forming apparatus 1 is improved.

  That is, as shown in FIG. 16, the image forming apparatus 1 captures the color measurement adjustment color patch CP of the color measurement adjustment sheet CS, obtains the initial color measurement target RGB value RsGsBs as described above, and determines the color measurement target RGB. When stored in the nonvolatile memory 125 as a value (step S21), the reference value linear conversion matrix is used (step S22), converted into a first XYZ value (step S23), and stored in the nonvolatile memory 125 (step S22). S24). For example, in FIG. 16, the colorimetric value calculation unit 126 converts the colorimetric target RGB values (3, 200, 5) of the imaging unit 30 into the first XYZ values (first colorimetric values) of (20, 80, 10). And stored in the nonvolatile memory 125.

  The colorimetric value calculation unit 126 converts the first XYZ value into a first Lab value (first colorimetric value) by referring to the memory table Tb1 of the nonvolatile memory 125 or using a known conversion formula. (Step S25), stored in the nonvolatile memory 125 (Step S26). For example, in FIG. 16, the colorimetric value calculation unit 126 converts the first XYZ value (20, 80, 10) into the first Lab value (75, −60, 8) that is the imaged colorimetric value.

  Next, the colorimetric value calculation unit 126 searches for the reference colorimetric values (Lab values) of the color patches of the plurality of colors in the memory table Tb1 stored in the nonvolatile memory 125, as indicated by the Lab space in FIG. Then, a set of color patches (neighboring color patches) that are close in distance to the first Lab value in the Lab space is selected from the reference colorimetric values (Lab values) (step S27). For example, the Lab space diagram of FIG. 16 shows a diagram in which 60 color patches are selected and plotted on the Lab space. For example, the first Lab can be selected as a method for selecting a patch having a short distance. The distance between the value and all points in the reference colorimetric values (Lab values) of the plurality of color patches is calculated, and the reference Lab value of the color patch that is close to the first Lab value that is the first colorimetric value (see FIG. 16, the hatched reference Lab value) is selected.

  Next, as shown in FIG. 17, the colorimetric value calculation unit 126 refers to the memory table Tb1, and sets the imaging reference RGB values paired with the first Lab value of the selected set, that is, the first Lab of the selected set. A combination of an imaging reference RGB value (selected RGB value) and a reference XYZ value having the same patch number as is selected (step S28), and a combination of the imaging reference RGB and reference XYZ of the selected combination (selected set) is converted. The selected RGB value linear transformation matrix is obtained using the least square method, and the obtained selected RGB value linear transformation matrix is stored in the nonvolatile memory 125 (step S29).

  The colorimetric value calculation unit 126 images each colorimetry adjustment color patch CP of the colorimetry adjustment sheet CS that is a colorimetry target by the image pickup unit 30 in which the opening 32b is opened, and digitally outputs it by the A / D converter 36. The converted colorimetric object RGB value is obtained using the selected RGB value linear conversion matrix to obtain a second XYZ value as a second colorimetric value (step S30), and the second XYZ value is converted into a second Lab value using a known conversion formula. (Step S31) and obtained as a final colorimetric value (step S32).

  The colorimetric value calculation unit 126 performs image adjustment based on the image data that has been color-converted using the obtained colorimetric value, and drives the recording head 20 based on the image data that has undergone image adjustment to form an image.

  In other words, the image forming apparatus 1 according to the present embodiment captures and acquires a plurality of color measurement adjustment color patches CP of the color measurement adjustment sheet CS reflecting the output characteristics of the recording head 20 at the color adjustment processing timing. The RGB values of the colorimetric object are obtained by obtaining a first Lab value when the reference sheet KS is imaged in the initial state using a reference value linear conversion matrix, and among the reference Labs of a plurality of color patches registered in the memory table Tb1 A pair of patches with a reference Lab value that is close to the first Lab value in the Lab space is selected, and the colorimetric RGB values corresponding to the selected reference Lab value are selected using the selected RGB value linear conversion matrix. Thus, the Lab colorimetric value is obtained by converting it into a Lab value. Then, the colorimetric value calculation unit 126 performs image adjustment based on the image data subjected to color conversion using the obtained colorimetric value, and drives the recording head 20 based on the image data subjected to image adjustment to form an image. To do.

  Then, when the image forming unit 30 captures the reference color patch KP of the reference sheet KS and when each of the color measurement adjustment color patches CP of the color measurement adjustment sheet CS is imaged as an imaging target, the frame 32. The patches Pa to Pd of the reference chart KC attached to the frame 32 are imaged. At this time, the openings 32b formed on the bottom surface 32a of the frame 32 are closed in order to image the patches with high accuracy. The shutter 38 is opened and moved to the standby position, the reference color patch KP of the reference sheet KS and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS are imaged, and the patches Pa to Pd of the reference chart KC are imaged. In this case, the shutter 38 to which the reference chart KC is attached is moved to a closed position (imaging position) that covers the opening 32b, and images are captured in the same positional relationship.

  In the imaging of the reference color patch KP of the reference sheet KS and the patches Pa to Pd of the reference chart KC, and the imaging of the color measurement adjustment color patch CP of the color measurement adjustment sheet CS and the patches Pa to Pd of the reference chart KC, the reference chart A simple imaging method in which all the patches Pa to Pd of KC are first imaged once, and then the color measurement adjustment color patch CP of the reference color patch KP of the reference sheet KS or the color measurement adjustment sheet CS is sequentially imaged; Any of the sequential imaging methods in which the imaging of the patches Pa to Pd of the chart KC and the imaging of the reference color patch KP of the reference sheet KS or the colorimetric adjustment color patch CP of the colorimetry adjustment sheet CS is sequentially repeated may be performed.

  First, the case of imaging with the simple imaging method will be described with reference to FIG. 18, but the image forming apparatus 1 performs the following imaging processing under the control of the CPU 101.

  When the image forming apparatus 1 captures images by the simple image capturing method, as illustrated in FIG. 18, when the timing of capturing the reference color patch KP of the reference sheet KS and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS is reached, the image forming apparatus 1 is initialized. As the state, the shutter opening / closing control unit 130 of the colorimetry control unit 106 sets the shutter 38 to which the reference chart KC is attached to the closed position (image pickup position) that closes the opening 32b. First, a patch of the reference chart KC is imaged (step S101). When imaging of all the patches Pa to Pd of the reference chart KC is completed, a motor drive signal is then output from the shutter opening / closing control unit 130 to drive the drive motor 47. Is driven to rotate, and the thin flat plate 41 is taken up by the take-up roller 43, and the shutter 38 is moved to the standby position outside the opening 32b. By moving performs shutter opening processing to open the opening 32 b (step S102).

  When the image forming apparatus 1 moves the shutter 38 to the standby position to open the opening 32b, the image forming apparatus 1 captures the reference color patch KP of the reference sheet KS or the colorimetric adjustment color patch CP of the colorimetric adjustment sheet CS to be imaged. The imaging unit 30 is moved to the position (step S103), and the imaging target is imaged through the opening 32b by the imaging unit 30 (step S104).

  When imaging of the imaging target is performed, the image forming apparatus 1 checks whether imaging of the entire range of the imaging target has been completed (step S105). If imaging of the entire range has not been completed, the process returns to step S103 to perform imaging. The imaging process similar to the above is performed from the movement of the unit 30 to the imaging target position (steps S103 to S105).

  When the image forming apparatus 1 completes imaging of the entire necessary range of the imaging target in step S <b> 105, the image forming apparatus 1 outputs a motor drive signal from the shutter opening / closing control unit 130 to rotate the drive motor 47, and from the take-up roller 43. A shutter closing process is performed in which the thin plate 41 is opened and the shutter 38 is moved from the standby position to the closing position on the opening 32b by the urging force of the compression spring 40 to close the opening 32b (step S106). When is closed, the imaging process is terminated.

  Next, a case where images are sequentially captured will be described with reference to FIG. 19, but the image forming apparatus 1 performs the following imaging processing under the control of the CPU 101.

  When the image forming apparatus 1 captures images by the sequential image capturing method, as illustrated in FIG. 19, when the timing of capturing the reference color patch KP of the reference sheet KS and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS is reached, the image forming apparatus 1 is initialized. As the state, the shutter opening / closing control unit 130 of the colorimetry control unit 106 sets the shutter 38 to which the reference chart KC is attached to the closed position (image pickup position) that closes the opening 32b. First, the patch of the reference chart KC is imaged (step S201), and when the imaging of all the patches Pa to Pd of the reference chart KC is completed, the reference color patch KP or the colorimetric adjustment of the reference sheet KS to be imaged is then performed. The imaging unit 30 is moved to the imaging target position of the colorimetric adjustment color patch CP of the sheet CS (step S202).

  Next, the image forming apparatus 1 outputs a motor drive signal from the shutter opening / closing control unit 130 to rotationally drive the drive motor 47 so that the thin plate 41 is taken up by the take-up roller 43 and the shutter 38 is opened. A shutter opening process for opening the opening 32b by moving to the standby position deviating from 32b is performed (step S203), and the imaging target 30 is imaged (step S204).

  When imaging of the imaging target is performed, the image forming apparatus 1 checks whether imaging of the entire range of the imaging target has been completed (step S205). If imaging of the entire range has not been completed, the shutter opening / closing control unit 130 controls the motor. A drive signal is output to rotate the drive motor 47 to release the thin plate 41 from the take-up roller 43, and the shutter 38 is moved from the standby position to the closed position on the opening 32b by the urging force of the compression spring 40. A shutter closing process for closing the opening 32b is performed (step S206).

  When the image forming apparatus 1 closes the shutter 38, the imaging unit 30 is moved to the next imaging target position while imaging the patches Pa to Pd in the entire range of the reference chart KC (step S207). .

  When completing the imaging of the reference chart KC and the movement of the imaging unit 30 to the next imaging target position, the image forming apparatus 1 moves the shutter 38 to the standby position and opens the opening 32b (step S203). Then, the next imaging target is imaged (step S204), and it is checked whether imaging of the entire range of the imaging target is completed (step S205).

  If the imaging of the entire range has not been completed in step S205, the same processing is performed from the closing process of the shutter 38 (steps S206, S207, and S202 to S205). When the imaging is completed, the shutter closing process for closing the shutter 38 is performed, and then the imaging process is terminated (step S208).

  Note that the opening / closing configuration of the opening 32b by the shutter 38 is not limited to the above-described slide method, and as shown in FIGS. 20 to 25, the shutter 38 is rotatably supported at one end, By rotating the support portion around the rotation center, the opening portion 32b is closed to move to the imaging position to image the reference chart KC, and the shutter 38 is rotated in the direction to open the opening portion 32b. You may make it image-capture the imaging target outside the imaging part 30 by moving to a standby position. 20 to 25, the same components as those in FIGS. 4 to 8 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  That is, as shown in FIGS. 20 to 25, in the imaging unit 50, a rectangular box-shaped frame body 32 whose surface on the substrate 31 side is open is fixed to the substrate 31 by the fastening member 33. The substrate 31 is fixed to the carriage 6.

  In the imaging unit 50, an opening 32b for imaging an imaging target is formed on a bottom surface portion 32a opposite to the substrate 31 of the frame body 32, and is an upper surface of the bottom surface portion 32a in the main scanning direction (both On one side (in the direction indicated by arrow A), a shutter 51 is rotatably attached by a hinge 52 with a spring. The shutter 51 has a shape that is slightly larger than the size of the opening 32b. As the spring-loaded hinge 52, a commercially available spring-loaded hinge can be used.

  Although not shown, the spring-equipped hinge 52 has a built-in spring that urges the shutter 51 in the direction of closing the opening 32b (the imaging position direction), and always closes the opening 32b with a predetermined urging force. Energized in the direction.

  The shutter 51 is detachably attached to a reference chart KC having the same size as the opening 32b in a state where the shutter 51 is in a closed position (image pickup position) that closes the opening 32b. 4 is the same as the reference chart KC.

  The shutter 51 is a surface on the side where the reference chart KC is attached, and is a position closer to the hinge 52 with the spring than the reference chart KC, and a predetermined amount of the reference chart KC in the main scanning direction from the hinge 52 with the spring. A pair of connecting portions 53 are fixed or formed integrally with the shutter 51 at positions that are separated from each other at a predetermined interval in the sub-scanning direction and symmetrical with respect to the sub-scanning direction of the shutter 51. The one end of the thin flat plate 41 is connected.

  The other end of the thin flat plate 41 is wound around a winding roller 43 that is attached to an outer surface on the spring-equipped hinge 52 side in the main scanning direction of the frame 32 via a cover 42.

  The take-up roller 43 is connected to a rotating shaft of a pulley 44, and the pulley 44 is connected to a pulley 46 by a belt 45. The pulley 46 is fixed to a rotating shaft of a winding motor 47 fixed to the side surface of the frame body 32. When the pulley 46 is rotationally driven by the winding motor 47, the pulley 44 rotates via the belt 45. Then, the winding roller 43 rotates in the same direction.

  When the take-up roller 43 rotates in the clockwise direction, the imaging unit 50 winds the thin flat plate 41 and opposes the shutter 51 against the biasing force of the spring of the spring-loaded hinge 52 via the connecting portion 53 of the shutter 51. The opening 32b is opened by rotating the image sensor 34 around the hinge 52 with a spring to an angular position (standby position) that does not interfere with the imaging of the subject outside the frame 32 through the opening 32b.

  When the take-up roller 43 rotates counterclockwise, the imaging unit 50 releases the thin flat plate 41, and the biasing force of the spring with the hinge 52 with the spring closes the opening 32b with the shutter 51 as the center with respect to the hinge 52 with the spring. The image is rotated in the direction, and is moved to the image pickup position that closes the opening 32 b by the shutter 51. That is, the hinge 52 with a spring, the thin flat plate 41, the cover 42, the take-up roller 43, the pulley 44, the belt 45, the pulley 46, and the take-up motor 47 as a whole are configured such that the shutter 51 that is a cover member is disposed on the opening 32b. It functions as a shutter opening / closing part (moving means) 54 that pivots and moves between a closing position for closing and an opening position for opening the opening 32b. Further, the shutter 51 is attached to the bottom surface portion 32a so as to be rotatable between an angle between the imaging position and the standby position with an angular position at which the image sensor unit 34 can capture an image of the subject through at least the opening 32b as a standby position. The shutter opening / closing part 54 resists the bias of the spring-equipped hinge (biasing means) 52 that biases the shutter 51 in the rotational direction from the standby position to the imaging position. A movement drive unit (movement drive means) 55 comprising a thin flat plate 41 for rotating the shutter 51 in the standby position direction, a cover 42, a take-up roller 43, a pulley 44, a belt 45, a pulley 46, and a take-up motor 47; It has.

  In this way, by rotating the shutter 51, the image pickup unit 50 can be downsized by opening and closing the opening 32b.

  The configuration for opening and closing the shutter 51 is not limited to the configuration using the spring-equipped hinge 52 and the thin flat plate 41. For example, the shutter 61 is supported like the imaging unit 60 shown in FIGS. It may be rotated around the shaft 62.

  That is, in the imaging unit 60, the shutter 61 is on one side in the main scanning direction (A direction), and in FIGS. 26 to 29, both ends in the sub scanning direction near the left end are side surfaces in the sub scanning direction of the frame 32. The surface of the shutter 61 closer to the bottom surface portion 32a on the left side in the main scanning direction than the support shaft 62 rotates about the support shaft 62. It is formed in a curved shape so that it can be easily performed.

  As shown in FIG. 28, the shutter 62 has a reference chart KC similar to the above detachably attached to the surface on the substrate 31 side, and a pair of guide grooves on the outside of both ends of the reference chart KC in the sub-scanning direction. 63 is formed. Stoppers 63a and 63b are provided at both ends of the guide groove 63 in the main scanning direction, respectively.

  A slider 64 is accommodated in the guide groove 63 so as to be movable in the main scanning direction while preventing the guide groove 63 from jumping out of the guide groove 63 to the outside. A compression spring 65 is disposed between the stopper 63b.

  The imaging unit 60 is connected to a slider 64 at one end of a thin flat plate 41 similar to the above, and the other end of the thin flat plate 41 is in the main scanning direction of the frame 32 and on the support shaft 62 side. It passes through a through hole (not shown) formed in the stopper 63b of the frame and is wound around a winding roller 43 attached to the outer surface of the frame pair 32 via a cover 42.

  The take-up roller 43 is connected to a rotating shaft of a pulley 44, and the pulley 44 is connected to a pulley 46 by a belt 45. The pulley 46 is fixed to a rotating shaft of a winding motor 47 fixed to the side surface of the frame body 32. When the pulley 46 is rotationally driven by the winding motor 47, the pulley 44 rotates via the belt 45. Then, the winding roller 43 rotates in the same direction.

  When the take-up roller 43 rotates in the clockwise direction, the imaging unit 60 winds the thin flat plate 41 against the urging force of the compression spring 65, pulls the slider 64 toward the stopper 63b, and moves the slider 64 together with the compression spring 65. By pressing against the stopper 63b, the shutter 61 is rotated counterclockwise about the support shaft 62, and the opening 32b is opened from the closed state shown in FIGS. 27 and 29 as shown in FIGS. Rotate to the open standby position.

  When the take-up roller 43 rotates counterclockwise, the imaging unit 60 releases the thin flat plate 41, and the urging force of the compression spring 65 pushes the slider 64 toward the stopper 63a, and the slider 64, the thin flat plate 41, and the compression plate 65 are compressed. The gravity of the spring 65 and the surface on the bottom surface portion 32a side in the vicinity of the support shaft 62 are formed into a curved shape, so that the shutter 61 rotates around the support shaft 62 in the direction of closing the opening 32b, The shutter 61 is rotated and moved to an imaging position that closes the opening 32b. That is, the support shaft 62, the groove 63, the stoppers 63a and 63b, the compression spring 65, the thin flat plate 41, the winding roller 43, the pulley 44, the belt 45, the pulley 46, and the winding motor 47 are cover members as a whole. The shutter 61 functions as a shutter opening / closing section (shutter opening / closing means) 66 that rotates and moves between a closed position (image pickup position) that closes the opening 32b and an open position (standby position) that opens the opening 32b. The shutter 61 is rotatably supported to open and close the opening 32b. The shutter opening / closing portion 66 includes a compression spring 65 that rotates and biases the shutter 61 in the standby position in the imaging position direction, and the thin flat plate 41. , A biasing portion (biasing means) 67 comprising a stopper 63a and a slider 64; a support shaft 62 for moving the shutter 61 in the standby position direction against the biasing force of the biasing portion 67; a groove 63; a stopper 63b; And a movement drive unit (movement drive means) 68 including a flat plate 41, a take-up roller 43, a pulley 44, a belt 45, a pulley 46, and a take-up motor 47.

  Thus, by rotating the shutter 61, the opening / closing portion 32b can be opened and closed to reduce the size of the imaging unit 50.

  Furthermore, the reference chart KC is not limited to the case where the reference chart KC is provided only for the shutters 38, 51, 61. For example, when the slide type shutter 38 is used, two reference charts KC1, KC2 may be provided. 30 to 32 is applied to an imaging device similar to the imaging device 30 shown in FIGS. 4 to 8, and the same components as the imaging device 30 of FIGS. 4 to 8. Are given the same reference numerals, and the description thereof is omitted or simplified.

  The imaging unit 70 is attached to the carriage 6 with the frame 32 facing the recording medium P on the platen 14 with the lower surface of the bottom surface portion 32a opposite to the substrate 31 having a predetermined distance d. In the bottom surface portion 32a, a substantially rectangular opening 32b is formed on one side in the main scanning direction (the direction indicated by the arrow A in FIGS. 30 to 32).

  In the imaging unit 70, a shutter 38 is disposed on the bottom surface 32a opposite to the opening 32b in the main scanning direction so as to be movable in the main scanning direction. The shutter 38 is the same as in the case of FIGS. Similarly, the both end surfaces in the sub-scanning direction have a size that can be moved while being guided by the inner wall surface in the sub-scanning direction of the frame body 32, and the both end surfaces in the sub-scanning direction are the inner wall surfaces of the frame body 32. Surface treatment is applied so that it can move smoothly while touching. The shutter 38 has a shape that is slightly larger than the size of the opening 32b.

  Although the imaging unit 70 is not illustrated, the shutter 38 is movable between the bottom surface part 32a on both inner wall surfaces in the sub-scanning direction of the frame 32, similarly to the imaging device 30 of FIGS. A guide member 39 for preventing the shutter 38 from floating is provided, and the guide member 39 is formed in a state in which a predetermined amount projects from the inner wall surface of the frame body 32 in the sub-scanning direction in the center direction in the sub-scanning direction in parallel to the bottom surface portion 32a. Thus, a guide groove 39a for guiding the movement of the shutter 38 in the main scanning direction is formed between the bottom surface portion 32a and the inner wall surface of the frame body 32.

  In the imaging unit 70, a reference chart KC1 is detachably attached to the upper surface (surface on the substrate 31 side) of the shutter 38, and the reference chart KC1 is the same as the reference chart KC shown in FIG. Further, in the main scanning direction, the imaging unit 70 has a recess 32c having the same size and shape as the opening 32b on the bottom surface 32a opposite to the opening 32b, and is attached to and detached from the recess 32c. A reference chart (second reference chart) KC2 is mounted as possible. As shown in FIG. 30, the reference chart KC2 has only colorimetric patches. 30 to 32, although not shown, unlike the cases of FIGS. 4 to 8, the shutter 38 has a closed position (imaging position) for closing the opening 32 b and an open position for opening the opening 32 b. The compression spring 40 and the thin flat plate 41 of the shutter opening / closing portion 48 to be moved to (standby position) are arranged at positions outside the reference chart KC2 in the sub-scanning direction.

  When the shutter 38 is moved to a closed position where the shutter 38 closes the opening 32b, the imaging unit 70 is in a state where the reference chart KC1 and the reference chart KC2 are arranged in parallel in the main scanning direction, as shown in FIG. An image sensor unit 34 is attached to a surface on the frame 32 side, at a position on a center line Lo passing through the center positions of the reference chart KC1 and the reference chart KC2. Similarly to the above, the image sensor unit 34 includes a two-dimensional image sensor 35 such as a CCD sensor or a CMOS sensor and a lens 36.

  The imaging unit 70 includes a pair of illumination light sources 37 mounted on a substrate 31 at a position on the center line Lo that is spaced apart from the center of the image sensor unit 34 by a predetermined amount in the sub-scanning direction. An LED or the like is used as the light source 37.

  When imaging the reference charts KC1 and KC2, the imaging unit 70 moves the shutter 38 to the closed position on the opening 32b and simultaneously captures the reference chart KC1 and the reference chart KC2, as shown in FIGS. .

  In addition, when the image capturing unit 70 captures the reference color patch KP of the reference sheet KS and the color measurement adjustment color patch CP of the color measurement adjustment sheet CS that is the image capturing target in the color adjustment processing, as illustrated in FIG. The part 38 moves the shutter 38 from the closed position (imaging position) on the opening 32b to the standby position off the opening 32b, and the colorimetric adjustment color of the reference color patch KP of the reference sheet KS and the colorimetric adjustment sheet CS. The patch CP is imaged.

  Therefore, the number of data serving as a reference in the color measurement process can be increased, and the accuracy of the color measurement process can be improved.

  As described above, in the image forming apparatus 1 according to the present embodiment, the imaging units 30, 50, and 60 are formed with the opening 32b for imaging the subject on the bottom surface (opposite surface) 32a facing the subject. A predetermined box-shaped frame 32, an illumination light source 37 that illuminates the opening 32b, an imaging position on the opening 32b in the frame 32, and a standby that opens from the opening 32b and opens the opening 32b. A shutter (shutter member) 38, 51, which is provided with a reference chart KC that provides a predetermined color reference on the surface irradiated with the illumination light source 37 in a state that is movable to a position and is located at the imaging position. 61, the reflected light from the object facing the opening 32b in a state where the shutters 38, 51, 61 are located at the standby position, and the reference chart KC when the shutters 38, 51, 61 are located at the imaging position Or By receiving the reflected light includes an image sensor unit (sensor unit) 34 for imaging the said subject and said reference chart KC, a.

  Accordingly, both the subject and the reference chart KC can be stably imaged, and the subject and the reference chart KC with respect to the image sensor unit 34 can be imaged in the same positional relationship, so that the subject and the reference chart KC are always stable. Therefore, it is possible to take an image with high accuracy in the positional relationship.

  Further, the imaging units 30, 50, 60 of the present embodiment include shutter opening / closing units (moving means) 48, 54, 66 for moving the shutters 38, 51, 61 to the imaging position and the standby position, and a shutter opening / closing unit. And a shutter opening / closing control unit (movement control means) 130 for controlling the movement of the shutters 38, 51, 61 by 48, 54, 66.

  Therefore, the shutters 38, 51, 61 can be automatically moved to the imaging position and the standby position in accordance with the imaging operation by the imaging units 30, 50, 60, and the subject and the reference chart KC are always in a stable positional relationship. High-precision and easy imaging can be performed.

  Further, in the imaging unit 30 of the present embodiment, the shutter 38 has an imaging position on the opening 32b along the bottom surface 32a in the frame 32 and a standby position on the bottom surface 32a that is off the opening 32b. The shutter opening / closing section 48 urges the shutter 38 at the standby position in the imaging position direction, and the shutter 38 against the urging force of the compression spring 40. A thin driving plate 41, a cover 42, a take-up roller 43, a pulley 44, a belt 45, a pulley 46, and a take-up motor 47, which are moved in the direction of the standby position, are provided.

  Therefore, the shutter 38 can be automatically moved to the imaging position and the standby position in accordance with the imaging operation by the imaging unit 30 with a simple configuration, and the subject and the reference chart KC are always highly accurate with a stable positional relationship. And it can image easily.

  In addition, the imaging units 50 and 60 of the present embodiment are configured such that the shutter members 51 and 61 have an imaging position and the standby position with an angular position where the image sensor unit 34 can capture an image of the subject through at least the opening 32b. Attached to the bottom surface portion 32a so as to be rotatable between angles, the shutter opening / closing portions (moving means) 54 and 66 are provided with springs that urge the shutters 51 and 61 in the rotating direction from the standby position to the imaging position. Hinge (biasing means) 52, biasing portion 67, thin flat plate 41, cover 42 for rotating shutters 51, 61 in the standby position direction against the biasing force of hinge 52 with spring, biasing portion 67, A movement drive unit (movement drive means) 55 comprising a take-up roller 43, a pulley 44, a belt 45, a pulley 46, and a take-up motor 47, a support shaft 62, a groove 63, a stopper 63b, a thin flat plate 41, Can up roller 43, a pulley 44, a belt 45, a transfer drive unit consisting of the pulleys 46 and the take-up motor 47 (the movement driving means) 68, a.

  Therefore, with a simple configuration, the shutters 51 and 61 can be automatically moved to the imaging position and the standby position in accordance with the imaging operation by the imaging units 50 and 60, and the subject and the reference chart KC are always in a stable positional relationship. With this, it is possible to pick up images with high accuracy and ease.

  Further, in the imaging unit 70 of the present embodiment, the shutter 38 is movable in parallel between the standby position aligned with the opening 32b along the bottom surface 32a, and the frame 32 is an image sensor of the bottom surface 32a. A reference chart (second reference chart) KC2 that provides a predetermined color reference is provided at the standby position of the shutter 38 on the surface of the unit 34 side.

  Therefore, the number of data serving as a reference in the color measurement process can be increased, and the accuracy of the color measurement process can be improved.

  In the above description, the color measurement process is performed by the color measurement control unit 106 of the image forming apparatus 1. However, the color measurement process does not need to be executed inside the image forming apparatus 1. For example, FIG. As shown, an image forming apparatus 210 is connected to an external apparatus 220 as an image forming system (colorimetry system) 200, and image data captured by the image forming apparatus 210 is output to the external apparatus 220. The external device 220 performs color adjustment processing that includes colorimetric processing, and outputs the color-adjusted image data to the image forming device 210. The image forming device 210 forms an image based on the image data from the external device 220. May be.

  That is, the image forming apparatus 210 includes an engine 211, an operation display unit 212, an I / F unit 213, other I / F units 214, and the like, and each unit is connected by a bus 215. In addition, the external device 220 can use, for example, a computer having a normal hardware configuration and software configuration, and includes a color adjustment program including a color measurement program that executes a color adjustment process accompanying the color measurement process of the present invention as software. The color adjustment process accompanied by the colorimetric process is executed by introducing. The external device 220 includes a CPU 221, a memory unit 222, an image processing unit 223, a communication I / F unit 224, an I / F unit 225, and the like, and each unit is connected by a bus 226. The memory unit 222 includes a ROM 227, a RAM 228, a hard disk (HDD) 229, and the like.

  The image forming apparatus 210 is connected to the external apparatus 220 via a line 230 by an I / F unit 213. The line 230 is a dedicated line, a network such as a LAN (Local Area Network), the Internet, and the like, and is wired. Or wireless.

  The image forming apparatus 210 forms and outputs an image on a recording medium with the engine 211 based on the image data sent from the external apparatus 220 under the control of the external apparatus 220. The engine 211 forms an image on a recording medium by an ink ejection method or the like, and the operation display unit 212 includes various operation keys and a display such as an LCD (Liquid Crystal Display), which are necessary for the operation of the image forming apparatus 210. Various operations are performed by the operation keys, and various information notified from the image forming apparatus 210 to the user is displayed on the display. The other I / F unit 214 is used for connecting an expansion unit.

  The engine 211 includes a carriage that moves in the main scanning direction similar to that described in the above-described embodiment, and the imaging unit 30 is attached to the carriage. The image forming apparatus 210 forms the color measurement adjustment patch CP on the recording medium based on the color patch data of the color measurement adjustment color patch CP sent from the external apparatus 220 under the control of the CPU 221 of the external apparatus 220. The color measurement adjustment sheet CS is generated, the color measurement adjustment patch CP of the generated color measurement adjustment sheet CS is read by the imaging unit, and transmitted to the external device 220 via the I / F unit 213.

  The external device 220 stores in the hard disk 229 or the ROM 227 an image formation control program for controlling the operation of the image forming apparatus 210, a color adjustment program for performing color adjustment processing accompanying colorimetric processing of the present invention, and necessary data. The CPU 221 controls the image forming apparatus 210 based on a program in the ROM 227 or the hard disk 229, thereby executing basic processing as the image forming apparatus 210 and executing color adjustment processing accompanying colorimetric processing of the present invention.

  The hard disk 229 stores the above program and various data necessary for executing the color adjustment processing, in particular, the colorimetry of the plurality of reference color patches KP arranged on the reference sheet KS described in the above embodiment. At least one of the resulting Lab value and XYZ value, imaging reference RGB value, reference value linear transformation matrix, and neighborhood point table when the reference patch KP of the reference sheet KS is read by the imaging unit of the image forming apparatus 210 And the selected RGB value linear conversion matrix, the initial reference RGB value RdGdBd of each color patch of the reference chart KC read together with the reference sheet KS, and the reference chart KC read when the colorimetric adjustment color patch CP of the color measurement adjustment sheet CS is read. The reference RGB value RdsGdsBds of the reference patch and the reference RGB value R of the color measurement Reference RGB between linear transformation matrix to convert the initial reference RGB value RdGdBd is stored SGdsBds.

  The communication I / F unit 224 is connected to an image processing apparatus such as a scanner apparatus, a composite apparatus, or another external apparatus via a line such as a network, and receives image data that causes the image forming apparatus 210 to output an image.

  The image processing unit 223 performs various image processes necessary for forming and outputting the image data with the engine 211 of the image forming apparatus 210.

  As described above, the CPU 221 controls the operation of the image forming apparatus 210 and also executes a colorimetric process executed by the calculation unit 124 of the colorimetry control unit 106, in particular, the colorimetric value calculation unit 126. , Color adjustment is performed on the image data based on the colorimetric value, and the image data is output to the image forming apparatus 210.

  In the image forming system 200 of FIG. 33, the external device 220 controls the operation of the image forming apparatus 210. However, the image forming apparatus 210 itself includes a controller such as a CPU. The external device 220 may execute only the color measurement process for which the controller controls and obtains the color measurement value, or only the color adjustment process including the color measurement process.

  As described above, when color adjustment processing including color measurement processing or color measurement processing is executed at least by an external device of the image forming apparatus 210, the color reproducibility can be appropriately improved at low cost even in the inexpensive image forming apparatus 210. it can.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body housing | casing 3 Main body frame 4 Main guide rod 5 Sub guide rod 6 Carriage 6a Connection piece 7 Timing belt 8 Drive pulley 9 Driven pulley 10 Main scanning motor 11 Cartridge part 12 Maintenance mechanism part 13 Cover 20y, 20m, 20c, 20k Recording head 21 Encoder sensor 30 Imaging unit 31 Substrate 32 Frame 32a Bottom surface part 32b Opening part 32c Recessed part 33 Fastening member 34 Image sensor part 35 Two-dimensional image sensor 36 Lens 37 Illumination light source 38 Shutter 39 Guide member 39a Guide groove 40 Compression spring 41 Thin flat plate 42 Cover 43 Winding roller 44 Pulley 45 Belt 46 Pulley 47 Winding motor 50 Imaging unit 51 Shutter 52 Spring hinge 53 Linking unit 54 Shutter opening / closing unit 60 Imaging 61 the shutter 62 support shaft 63 the guide grooves 63a, 63b stopper 64 slider 65 the compression spring 66 the shutter opening and closing section 70 imaging section 101 CPU
102 ROM
103 RAM
104 Main Scan Driver 105 Recording Head Driver 106 Colorimetry Control Unit 107 Paper Transport Unit 108 Sub Scan Driver 110 Image Processing Unit 111 Interface Unit 112 A / D Conversion Unit 113 Shading Correction Unit 114 White Balance Correction Unit 115 γ Correction Unit 116 Image Format Conversion unit 121 Frame memory 122 Timing signal generation unit 123 Light source drive control unit 124 Calculation unit 125 Non-volatile memory 126 Colorimetric value calculation unit 130 Shutter opening / closing control unit 200 Image forming system 210 Image forming apparatus 211 Engine 212 Operation display unit 213 I / F unit 214 Other I / F unit 215 Bus 220 External device 221 CPU
222 Memory unit 223 Image processing unit 224 Communication I / F unit 225 I / F unit 226 Bus 227 ROM
228 RAM
229 Hard disk 230 Line Tb1 Memory table KS Reference sheet KP Reference color patch CS Color measurement adjustment sheet CP Color measurement adjustment patch KC, KC1, KC2 Reference chart Pa to Pd Reference color patch array Pe Dot diameter measurement pattern array lk Distance measurement line mk Chart position marker

JP-A-5-223642

Claims (7)

A predetermined box-shaped frame in which an opening for imaging the subject is formed on a facing surface portion facing the subject;
An illumination light source for illuminating the opening;
And over said opening of said frame body, movable in a standby position aligned with the opening for opening the opening out from the opening portion on a predetermined on a surface of the side to be irradiated prior Symbol illumination source A shutter member provided with a reference chart for providing a color reference of
A second reference chart that is provided at the standby position of the shutter member and is a surface on the sensor means side of the facing surface portion and provides a predetermined color reference;
Reflected light from the subject facing the opening when the shutter member is positioned at the standby position , and the reference chart and the second reference chart when the shutter member is positioned on the opening Sensor means for receiving reflected light from and imaging the subject, the reference chart, and the second reference chart ;
An imaging apparatus comprising: The imaging device
Moving means for moving the shutter member on the opening and the standby position;
Movement control means for controlling movement of the shutter member by the movement means;
The imaging apparatus according to claim 1, further comprising: The shutter member is
A translational movement is possible along the facing surface portion in the frame body to the standby position on the opening portion and the facing surface portion that is off the opening portion;
The moving means is
Biasing means for biasing the shutter member at the standby position upward in the opening ;
Moving drive means for moving the shutter member in the direction of the standby position against the urging force of the urging means;
The imaging apparatus according to claim 2, further comprising: The imaging device
The subject is imaged for each of a plurality of partial subjects through the opening with the shutter member being positioned at the standby position,
The movement control means includes
Each time the partial subject is imaged, the shutter member is moved onto the opening via the moving means, and when the reference chart is imaged by the sensor means, the shutter member is moved to the standby position. The imaging apparatus according to claim 2 or 3 , wherein An imaging means for imaging a reference chart composed of a plurality of colors and an arbitrary subject;
Calculation means for calculating a colorimetric value of the subject based on the subject imaged by the imaging means and imaging data of the reference chart;
A colorimetric device comprising:
As the imaging means, colorimetry apparatus characterized by an image pickup apparatus according to any one of claims 1 to 4. An imaging means for imaging a reference chart composed of a plurality of colors and an arbitrary subject;
Calculation means for calculating a colorimetric value of the subject based on the subject imaged by the imaging means and imaging data of the reference chart;
Communication means for connecting the imaging means and the calculation means;
A colorimetric system comprising:
Colorimetric system, characterized in that as the imaging means includes an imaging device according to any one of claims 1 to 4. An image forming apparatus that forms an image using image data that has been color-adjusted based on a colorimetric value measured by a colorimeter,
An image forming apparatus comprising the color measuring device according to claim 5 as the color measuring device.