JP5794371B2 - Recording device - Google Patents

Description

  The present invention relates to a recording apparatus such as an ink jet printer.

  An ink jet recording apparatus ejects ink from a recording head mounted on a carriage during reciprocation in the main scanning direction (carriage movement direction), deposits ink on a recording medium on a platen plate, and images on the recording medium. (Dot) is recorded. Then, the recording medium is conveyed in the sub-scanning direction (a direction orthogonal to the carriage movement direction) using a conveyance roller or the like, and recording in the main scanning direction is repeated to form an image on the recording medium. The platen plate is for supporting the recording medium when ink is ejected onto the recording medium.

  In the above-described ink jet recording apparatus, the amount of ink ejected from the recording head varies depending on the nozzle state of the recording head, ink viscosity variation, variation in piezo elements for ejection driving, and the like. For this reason, variation occurs in the color reproduction of the image formed by the ink ejected from the recording head. Further, the ink discharge amount changes with time in one apparatus or varies from one apparatus to another. For this reason, also in this case, the color reproduction of the image formed by the ink ejected from the recording head varies.

  For this reason, in the ink jet recording apparatus described above, for example, a test pattern to be colorimetric is formed on a recording medium, the color of the test pattern is measured with a colorimeter, and the color measurement of the test pattern is performed. Depending on the result, there is a control that corrects the ejection amount of the ink ejected from the recording head and controls the color reproduction of the image formed by the ink ejected from the recording head to be constant.

  Examples of the colorimeter described above include one that performs color measurement using a spectroscope and one that receives reflected light from a test pattern and performs color measurement. However, although the spectroscope can increase the accuracy of colorimetry, since it is expensive, mounting the spectroscope on the recording apparatus leads to an increase in cost. In addition, a colorimeter using reflected light is inexpensive, but the reflected light changes depending on the environmental conditions, so that the colorimetric accuracy is deteriorated.

  In addition, as a technical document filed prior to the present invention, Patent Document 1 (Japanese Patent No. 3129502) discloses a subject including a reference color chart and a color object to be measured simultaneously or separately, and a reference color chart. In addition, a technique for acquiring RGB data of a measured color object, correcting the RGB data of the measured color object based on the acquired RGB data of the reference color chart, and improving the color measurement accuracy is disclosed. .

  Patent Document 1 discloses that a subject including a reference color chart and a color object to be measured is simultaneously imaged and the RGB data of the color object to be measured is corrected.

  However, the technique of Patent Document 1 is based on the premise that imaging is performed with the position of the imaging device and the subject fixed, and cannot be used when the imaging device moves.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a recording apparatus that can be used even when an imaging apparatus moves.

The recording apparatus according to the present invention includes:
A recording device having a recording means and an imaging device,
The recording means records a test pattern on a recording medium using a recording agent,
The imaging device
A housing having an opening in the first wall, a second wall facing the first wall, and a side wall connecting the first wall and the second wall. Body,
A reference pattern composed of a plurality of color patches and disposed on the side wall;
A two-dimensional sensor that images the test pattern through the opening in a part of the imaging region and images the reference pattern in the other region;
The two-dimensional sensor, and an imaging element that is disposed on an optical path of the reference pattern and the test pattern and forms an image of the reference pattern on a sensor surface of the two-dimensional sensor;
A reflecting member that is disposed in an optical path between the two-dimensional sensor and the reference pattern, and that matches an imaging position of the image of the test pattern and an imaging position of the image of the reference pattern;
With
The amount of the recording agent used for recording by at least the recording unit changes based on the image data of the plurality of color patches in the captured image data captured by the two-dimensional sensor and the image data of the test pattern. Features.

  According to the present invention, it can be used even when the imaging apparatus moves.

FIG. 2 is a diagram illustrating a schematic configuration example of a mechanism unit of a recording apparatus according to an embodiment. It is a figure which shows the example of schematic structure of the recording mechanism of the recording device of this embodiment, and a detection mechanism. 3 is a diagram illustrating a configuration example of a recording head 6. FIG. 3 is a diagram illustrating a first configuration example of an imaging unit. FIG. 3 is a diagram illustrating a second configuration example of an imaging unit. FIG. FIG. 3 is a diagram illustrating a schematic configuration example of a control mechanism of the recording apparatus according to the embodiment. 4 is a diagram illustrating a configuration example of a reference chart 400. FIG. 4 is a diagram for explaining an example of a color measurement method for a test pattern 100. FIG. It is a figure which shows the RGB output value before gray balance and white balance adjustment, and an ideal RGB output value. It is a figure which shows the difference of an actual RGB output value and an ideal RGB output value, and ratio of an actual RGB output value and an ideal RGB output value. 4 is a diagram for explaining an example of a color measurement method for a test pattern 100. FIG. It is a figure which shows the conversion type | formula of Lab-> XYZ and XYZ-> Lab. 4 is a diagram for explaining an example of a color measurement method for a test pattern 100. FIG. It is a 1st figure for demonstrating position shift correction of an image. It is a 2nd figure for demonstrating position shift correction of an image. It is a 3rd figure for demonstrating position shift correction of an image. It is a 4th figure for demonstrating position shift correction of an image. It is a figure which shows the other example of a mode of image position shift correction | amendment.

(First embodiment)
<Example of schematic configuration of mechanism of recording apparatus>
First, a schematic configuration example of a mechanism unit of the recording apparatus according to the present embodiment will be described with reference to FIG.

  In the recording apparatus of the present embodiment, the main support guide rod 3 and the sub support guide rod 4 are horizontally mounted between the side plates 1 and 2 on both sides in a substantially horizontal positional relationship, and the main support guide rod 3 and the sub support guide rod 4 The carriage 5 is configured to be slidably supported in the main scanning direction.

  The carriage 5 has a plurality of recording heads 6y, 6m, 6c, 6k that discharge yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (Bk) ink, and their discharge surfaces (nozzle surfaces). Is mounted facing downward. In addition, the carriage 5 includes a plurality of ink cartridges 7 (the reference numeral “7” is a symbol “6” means any one of “6y, 6m, 6c, 6k” or a generic name) 7y, 7m, 7c, 7k ”(which means generic name) is interchangeably mounted. The ink cartridge 7 is an ink supply body for each color for supplying ink to the recording head 6. The carriage 5 is connected to a timing belt 11 stretched between a driving pulley 9 rotated by a main scanning motor 8 and a driven pulley 10, and moved in the main scanning direction by controlling the driving of the main scanning motor 8. It is configured to do. The movement in the main scanning direction is controlled based on an encoder value obtained by providing an encoder sensor 41 on the carriage 5 and detecting the mark on the encoder sheet 40 as shown in FIG.

  Further, the recording apparatus of the present embodiment is configured such that the subframes 13 and 14 are erected on the bottom plate 12 that connects the side plates 1 and 2, and the transport roller 15 is rotatably held between the subframes 13 and 14. ing. A sub-scanning motor 17 is disposed on the sub-frame 14 side, and in order to transmit the rotation of the sub-scanning motor 17 to the conveying roller 15, a gear 18 fixed to the rotation shaft of the sub-scanning motor 17 and the conveying roller 15 And a gear 19 fixed to the shaft.

  Further, between the side plate 1 and the subframe 13, a reliability maintaining and recovering mechanism (hereinafter referred to as "subsystem") 21 of the recording head 6 is disposed. The subsystem 21 is configured by holding a cap means 22 for capping the ejection surface of the recording head 6 by a holder 23 and holding the holder 23 by a link member 24 so as to be swingable. Then, when the carriage 5 moves in the main scanning direction and the carriage 5 comes into contact with the engaging portion 25 provided in the holder 23, the holder 23 lifts up, and the cap means 22 caps the ejection surface of the recording head 6. Like to do. Further, when the carriage 5 moves to the image forming area (on the recording medium 16), the holder 23 is lifted down so that the cap means 22 is separated from the ejection surface of the recording head 6.

  The cap means 22 is connected to the suction pump 27 via the suction tube 26, forms an atmosphere opening port, and communicates with the atmosphere via the atmosphere opening tube and the atmosphere opening valve. The suction pump 27 discharges the sucked waste liquid (waste ink) to a waste liquid storage tank.

  A wiper blade 30 for wiping the discharge surface of the recording head 6 is attached to the blade arm 31 at the side of the holder 23. The blade arm 31 is pivotally supported and rotated by a driving means (not shown). The cam is swung by the rotation of the cam.

<Configuration example of recording mechanism and detection mechanism of recording apparatus>
Next, configuration examples of the recording mechanism and the detection mechanism of the recording apparatus according to the present embodiment will be described with reference to FIGS. FIG. 2 is a diagram for explaining the upper surface of the carriage 5, and FIG. 3 is a diagram showing an arrangement example of the recording heads 6.

  The recording mechanism and detection mechanism of the recording apparatus according to the present embodiment are configured to include a carriage 5, an encoder sheet 40, and a platen plate 200. The carriage 5 includes a recording head 6, an encoder sensor 41, and an imaging unit 42.

  The platen plate 200 is for supporting the recording medium 16 when ink is ejected onto the recording medium 16. Since the printing apparatus according to the present embodiment is a wide machine having a long scanning movement distance in the main scanning direction, the platen plate 200 is configured by connecting a plurality of plate-like members in the main scanning direction (carriage movement direction).

  The recording head 6 includes a plurality of nozzle rows, ejects ink onto the recording medium 16 conveyed on the platen plate 200, and records an image (dot) on the recording medium 16. In order to secure a large recording width capable of recording an image (dot) on the recording medium 16 in one scan, the recording head 6 of the present embodiment, as shown in FIG. And a recording head constituting the downstream side. Further, in order to improve the black recording speed, the black recording heads 6k are arranged twice as many as the color recording heads 6y, 6m, and 6c. Also, the color recording heads 6y and 6m are arranged separately on the left and right. This is because the order of color overlap is adjusted by the reciprocating operation of the carriage 5 so that the color does not change between the forward path and the return path. Note that the arrangement of the recording heads 6 shown in FIG. 3 is an example, and is not limited to the arrangement shown in FIG.

  The recording mechanism of the present embodiment moves the carriage 5 on which the recording head 6 is mounted in the main scanning direction, ejects ink from the nozzle array of the recording head 6 onto the recording medium 16 on the platen plate 200, and performs color measurement. A test pattern 100 is recorded on the recording medium 16. The test pattern 100 is mainly used for measuring the color of an image formed by the ink ejected from the recording head 6.

  Further, the detection mechanism of the present embodiment images the test pattern 100 recorded on the recording medium 16 and a reference chart (not shown) arranged in the imaging unit 42 with the imaging unit 42. Then, the color of the test pattern 100 captured by the imaging unit 42 is compared with the color of the reference chart, and the color of the test pattern 100 is measured. The reference chart is mainly used when measuring the color of the test pattern 100.

<Configuration Example of Imaging Unit 42>
Next, a configuration example of the imaging unit 42 will be described with reference to FIG. 4A and 4B are diagrams illustrating a configuration example of the imaging unit 42, where FIG. 4A illustrates a configuration example of the side surface of the imaging unit 42, and FIG. 4B illustrates a configuration example of the upper surface of the imaging unit 42.

  The imaging unit 42 of the present embodiment includes a housing 421 having an opening 428 on the imaging surface side, a two-dimensional sensor 423, a light source (LED: Light Emitting Diode) 424, an imaging lens 425, and a reflecting member 426. And a support member 427 and a reference chart 400.

  The housing 421 constitutes the outside of the imaging unit 42, and has an opening 428 on the imaging surface side. The inner surface of the housing 421 has a rectangular shape as shown in (b), and a reference chart 400 is arranged as shown in (a). The two-dimensional sensor 423 captures the reference chart 400 and the subject (test pattern 100) at the same time, and acquires a two-dimensional captured image composed of the reference chart 400 and the test pattern 100. The light source 424 irradiates the reference chart 400 and the test pattern 100 with light. The imaging lens 425 is a lens that forms an image to be imaged on the sensor surface of the two-dimensional sensor 423, and this imaging lens 425 is arranged so that the object plane position is on the test pattern 100. The reflection member 426 is a member that reflects light, and has a predetermined reflectance. The reflection member 426 causes the focal plane to be adjusted on the reference chart 400 disposed on the inner surface of the housing 421. Yes. The support member 427 has a predetermined angle (θ) and supports the reflection member 426.

  The imaging unit 42 of this embodiment images the test pattern 100 in an area that is approximately half the imaging area of the two-dimensional sensor 423. The test pattern 100 is focused on the test pattern 100 by the imaging lens 425. In addition, the reference chart 400 is imaged in an approximately half area of the imaging area of the two-dimensional sensor 423. The reference chart 400 is focused on the reference chart 400 by the reflecting member 426.

  The imaging unit 42 of the present embodiment arranges the reflection member 426 so that the focal plane is aligned on the reference chart 400, and the two-dimensional sensor 423 indicates the image formation position of the reference chart 400 and the image formation position of the test pattern 100. It is supposed to be the sensor surface.

  Further, the imaging unit 42 of the present embodiment irradiates the reference chart 400 and the test pattern 100 with light using the light source 424, and simultaneously images the reference chart 400 and the test pattern 100 with the two-dimensional sensor 423 under the same illumination conditions. I am going to do it.

  In FIG. 4, a support member 427 that supports the reflection member 426 at a predetermined angle (θ) is disposed in the housing 421, and the reflection member 426 is installed on the support member 427 to form an image of the reference chart 400. The position and the image formation position of the test pattern 100 are made to coincide with each other.

  However, as shown in FIG. 5, a part of the casing 429 on the imaging surface side of the casing 421 can be bent steplessly, and the reflecting member 426 is placed on the part of the casing 429 that can be bent steplessly. It is also possible to make the image formation position of the reference chart 400 coincide with the image formation position of the test pattern 100. In FIG. 5, the reflective member 426 is installed on a part of the case 429 that can be bent steplessly. However, a material that becomes a reflector is formed on the part of the case 429 that can be bent steplessly. The casing 429 itself can also be configured to serve as the reflecting member 426.

<Configuration example of control mechanism of recording apparatus>
Next, a configuration example of the control mechanism of the recording apparatus of the present embodiment will be described with reference to FIG.

  The control mechanism of the recording apparatus according to the present embodiment includes a control unit 107, ROM 118, RAM 119, storage unit 120, carriage 5, main scanning driver 109, recording head 6, recording head driver 111, encoder sensor 41, imaging unit 42, paper conveyance The unit 112 and the sub-scanning driver 113 are included.

  The control unit 107 supplies recording data and a drive control signal (pulse signal) to the storage unit 120 and each driver, and controls the entire recording apparatus. The control unit 107 controls driving of the carriage 5 in the main scanning direction via the main scanning driver 109. Further, the ink ejection timing by the recording head 6 is controlled via the recording head driver 111. Further, the driving of the paper conveyance unit 112 (conveyance belt or the like) in the sub scanning direction is controlled via the sub scanning driver 113.

  The encoder sensor 41 outputs an encoder value obtained by detecting the mark on the encoder sheet 40 to the control unit 107. The control unit 107 controls driving of the carriage 5 in the main scanning direction via the main scanning driver 109 based on the encoder value.

  The imaging unit 42 simultaneously captures the reference chart 400 arranged in the imaging unit 42 and the test pattern 100 recorded on the recording medium 16, and controls the captured image configured by the reference chart 400 and the test pattern 100. Output to the unit 107. The control unit 107 compares the color of the reference chart 400 with the color of the test pattern 100 based on the captured image obtained from the imaging unit 42, and measures the color of the test pattern 100.

  The ROM 118 stores necessary information. For example, a program such as a processing procedure executed by the control unit 107 is stored. The RAM 119 is used as a working memory or the like.

<Configuration example of the reference chart 400>
Next, a configuration example of the reference chart 400 will be described with reference to FIG.

  The reference chart 400 according to the present embodiment includes a pattern row for color measurement and a pattern row for geometric shape measurement.

  The color measurement pattern columns include a YMCK primary color tone pattern row 401, an RGB secondary color tone pattern row 402, a grayscale tone pattern row 403, and a tertiary color tone pattern row 404. is there.

  The pattern rows for measuring the geometric shape include a distance measurement line (outer frame line) 405 and a circular pattern row 406 for measuring the dot diameter. Four corners 407 of the outer frame line 405 are markers for specifying the position of the reference chart 400. The control unit 107 can specify the position of the reference chart 400 by specifying the four corners 407 of the outer frame line 405 from the captured image obtained from the imaging unit 42.

  The Lab value of each patch constituting each pattern row 401, 402, 403, 404, 406 is measured in advance, and becomes a reference value when measuring the color of the test pattern 100. Note that the configuration of each pattern row 401, 402, 403, 404, 406 is not particularly limited, and any pattern row can be applied. For example, it is possible to use a patch whose color range can be specified as wide as possible, or to be able to replace the patch according to the purpose of use. In addition, the CMYK primary color gradation pattern row 401 and the grayscale gradation pattern row 403 can also be configured with colorimetric values of ink used in the printing apparatus. The gradation pattern row 402 of the secondary color of RGB can also be configured with colorimetric values that can be developed with ink used in the printing apparatus. Alternatively, it is possible to use a reference color chart in which colorimetric values such as Japan Color are defined.

<Example of color measurement method for test pattern 100>
Next, an example of a color measurement method for the test pattern 100 will be described with reference to FIG.

  When performing colorimetry of the test pattern 100, the test pattern 100 having the configuration shown in FIG. 8 is recorded on the recording medium 16, and the reference chart 400 and the test pattern 100 are simultaneously imaged by the imaging unit 42, as shown in FIG. A captured image is acquired. Of the entire imaging region (two-dimensional sensor total imaging region) of the two-dimensional sensor 423 shown in FIG. 8, the imaging region on the left half surface constitutes the reference chart imaging region, and the reference chart 400 shown in FIG. It is assumed that the Lab value of each patch constituting the reference chart 400 is measured and grasped in advance. The imaging area on the right half constitutes the subject imaging area, and the test pattern 100 shown in FIG. 8 is imaged. The test pattern 100 is preferably composed of a large number of colors in order to obtain a color profile, but may be composed of a small number of colors depending on the purpose.

  When the captured image shown in FIG. 8 is acquired, the positions of the four corners 407 of the outer frame line (main scanning / sub-scanning distance reference line) 405 of the reference chart 400 are first specified by pattern matching or the like. Thereby, the position of the reference chart 400 can be specified. After specifying the position of the reference chart 400, the position of each patch constituting the reference chart 400 is specified.

  Next, in order to calibrate the image sensor sensitivity, the RGB value of each patch constituting the reference chart 400 is acquired. Specifically, among the patches that make up the reference chart 400, the RGB values of the achromatic patches ((white, black, grayscale)) are acquired. Get RGB values of chromatic colors (white, black, grayscale).

  FIG. 9 shows RGB output values before gray balance and white balance adjustment. If the RGB values acquired from the captured image shown in FIG. 8 are output as they are without adjusting the balance, the RGB output values as shown in FIG. 9 are obtained, and the colors are not balanced and have saturation. Will be output. This is because the two-dimensional sensor 423 has an error due to sensitivity variations. Essentially, all RGB output values are ideally output as values having linearity on the dotted line shown in FIG. For this reason, the recording apparatus according to the present embodiment has a difference between the actual RGB output value (solid line) acquired from the captured image shown in FIG. 8 and the ideal RGB output value (dotted line), or the actual RGB output value and the ideal RGB output value. A ratio with the RGB output value is obtained, and the obtained difference or ratio is temporarily stored in the storage unit 120. FIG. 10 shows the difference between the actual RGB output value (solid line) and the ideal RGB output value (dotted line), and the ratio between the actual RGB output value and the ideal RGB output value. The recording apparatus of the present embodiment can obtain an RGB output value having linearity by correcting the actual RGB output value using the difference or ratio shown in FIG. 10 stored in the storage unit 120.

  Further, it is preferable to perform appropriate interpolation processing such as spline interpolation and polynomial interpolation between the actual RGB output values shown in FIG. Then, the difference or ratio between the RGB output value obtained by performing the interpolation process between the actual RGB output values shown in FIG. 9 and the ideal RGB output value is obtained, and the obtained difference or ratio is calculated. By correcting the actual RGB output value using the difference or the ratio stored in the storage unit 120 and stored in the storage unit 120, it is possible to obtain an RGB output value with further linearity.

  Next, an example of a method for obtaining the Lab value from the RGB value acquired from the test pattern 100 will be described with reference to FIGS.

  FIG. 11C shows Lab values of patches of the primary color gradation pattern sequence 401 (YMCK) and the secondary color gradation pattern sequence 402 (RGB) of the reference chart 400 shown in FIG. The values measured in advance) are plotted on the Lab color space.

  FIG. 11A shows a two-dimensional sensor for each patch of the primary color gradation pattern sequence 401 (YMCK) and the secondary color gradation pattern sequence 402 (RGB) of the reference chart 400 shown in FIG. The RGB values obtained by reading at 423 are plotted in the RGB color space.

  FIG. 11B is a graph in which the Lab value shown in FIG. 11C is converted by a predetermined formula (Lab → XYZ), and the converted XYZ value is plotted in the XYZ color space. When converting Lab values to XYZ values, they can be converted using the conversion formula shown in FIG. 12 (a) (Lab => XYZ). Further, when converting XYZ values to Lab values, they can be converted using the conversion formula shown in FIG. 12B (XYZ = Lab). Therefore, the Lab value shown in FIG. 11 (c) and the XYZ value shown in FIG. 11 (b) can be mutually converted by the conversion formulas shown in FIGS. 12 (a) and 12 (b).

  Assume that the RGB value of an arbitrary patch of the test pattern 100 to be measured obtained from the subject imaging area shown in FIG. 8 is at the Prgb point in the RGB space shown in FIG. In this case, first, the nearest four points that can form a tetrahedron including the Prgb point shown in FIG. 11A are searched (step S1). In FIG. 11A, p0, p1, p2, and p3 are selected. The coordinate values of the four points (p0, p1, p2, p3) in the RGB space shown in FIG. 11A are represented by p0 (x01, x02, x03), p1 (x1, x2, x3), p2 (x4, x5, x6) and p3 (x7, x8, x9).

  Next, four points (q0, q1, q2, q3) in the XYZ space shown in FIG. 11 (b) corresponding to the four points (p0, p1, p2, p3) in the RGB space shown in FIG. 11 (a). Is searched (step S2). The coordinate values of four points (q0, q1, q2, q3) in XYZ space are expressed as q0 (y01, y02, y03), q1 (y1, y2, y3), q2 (y4, y5, y6), q3 ( y7, y8, y9).

  Next, a linear transformation matrix for linearly transforming the local space in the tetrahedron is obtained (step S3). Specifically, among the four points (p0, p1, p2, p3), an arbitrary pair of corresponding points is determined (in this embodiment, p0, q0 closest to the achromatic color), and the corresponding points ( p0, q0) is the origin (the coordinate values of p1 to p3 and q1 to q3 are relative values from p0 and q0).

  Assuming that the conversion formula between the RGB space shown in FIG. 11 (a) and the XYZ space shown in FIG. 11 (b) can be linearly converted to Y = AX, X is shown in FIG. 11 (a). It is represented by a point on the RGB space, and Y is represented by a point on the XYZ space shown in FIG.

  Next, using this linear transformation matrix (Y = AX), the RGB value (Prgb) shown in FIG. 11A obtained by the two-dimensional sensor 423 is mapped onto the XYZ space shown in FIG. 11B. (Step S4). Thereby, the Pxyz value in the XYZ space shown in FIG. 11B can be obtained.

  Next, the Pxyz value obtained by mapping on the XYZ space shown in FIG. 11 (b) is converted into an Lab value by a general XYZ → Lab conversion formula, and corresponds to the RGB value shown in FIG. 11 (a). Lab value is obtained (step S5). When converting the XYZ value to the Lab value, it can be converted by the equation shown in FIG.

  As a result, even if the sensitivity of the two-dimensional sensor 423 changes or the wavelength or intensity of the light source 424 changes, the reference chart 400 and the test pattern 100 are imaged simultaneously, and the test is performed while constantly comparing with the reference chart 400. By performing the color measurement of the pattern 100, highly accurate color measurement can be performed.

  For this reason, the recording apparatus of the present embodiment compares the Lab value of the test pattern 100 measured using the imaging unit 42 with the Lab value that is originally intended to be recorded on the recording medium 16, and records based on the difference. By correcting the ejection amount of the ink ejected from the head 6 and the image data itself, the color of the image formed by the ink ejected from the recording head 6 can be brought close to the target color originally intended to be recorded on the recording medium 16. it can. In the present embodiment, the test pattern 100 is the target of colorimetry, but there may be a case where color measurement is performed on a recorded image that is not the test pattern 100 for a printing test or the like. In this case, the colorimetric object is a recorded image.

  The image formed on the recording medium 16 is generally formed of a dot matrix, and a desired color is reproduced by superimposing inks such as YMCK. However, if there is an image misalignment, image degradation occurs and the colorimetric value itself obtained from the test pattern 100 changes.

  If the color of the image has changed due to the displacement of the image formed on the recording medium 16, and if the color of the image formed on the recording medium 16 is corrected only by the ink discharge amount, each ink The balance of the discharge amount is lost, and a good image cannot be obtained. For this reason, it is preferable to correct the image misalignment before the color measurement of the test pattern 100 is performed. Hereinafter, correction of image misregistration will be described.

<Example of image displacement correction method>
Next, an example of an image misalignment correction method will be described with reference to FIG.

  When correcting the positional deviation of the image, the test pattern 100 shown in FIG. 14 is recorded on the recording medium 16, the reference chart 400 and the test pattern 100 are simultaneously imaged by the imaging unit 42, and the captured image shown in FIG. get.

  Of the entire imaging region (two-dimensional sensor total imaging region) of the two-dimensional sensor 423 illustrated in FIG. 14, the imaging region on the left half constitutes the reference chart imaging region, and the reference chart 400 illustrated in FIG. 7 is captured. Further, the imaging area on the right half surface constitutes the subject imaging area, and the test pattern 100 shown in FIG. 14 is imaged.

  The vertical line (solid line) in the lower half area of the subject imaging area of the test pattern 100 shown in FIG. 14 is a pattern for measuring the relative positional deviation of the upstream recording head 6 in the main scanning direction. The vertical line (solid line) in the upper half area of the subject imaging area of the test pattern 100 is a pattern for measuring the relative positional deviation in the main scanning direction of the recording head 6 on the downstream side. Further, the horizontal line (solid line) in the middle of the subject imaging area of the test pattern 100 is a pattern for measuring the relative displacement in the sub-scanning direction between the upstream recording head 6 and the downstream recording head 6. It is. 14 indicates the position of an ideal vertical line recorded on the recording medium 16 when there is no position shift in the main scanning direction, and is not actually recorded on the recording medium 16. It is a vertical line.

  When measuring the relative positional deviation of the upstream recording head 6 in the main scanning direction, first, the interval between vertical lines (solid lines) actually recorded on the recording medium 16 is shifted from the recording head 6 by a predetermined interval α. The actual vertical line position (solid line) recorded on the recording medium 16 and the ideal vertical line position (dotted line) recorded on the recording medium 16 when there is no positional deviation in the main scanning direction. ) Is calculated as a positional deviation amount in the main scanning direction. The interval between the vertical lines (solid lines) actually recorded on the recording medium 16 is measured using the black vertical line recorded on the leftmost side as a reference line for measuring the main scanning position deviation.

  Specifically, as shown in FIG. 15, the first black vertical line recorded on the leftmost side is used as a main scanning position deviation measurement reference line, and the reference line and the actually recorded vertical line are Measure the interval (x1, x2, x3). Thereby, the position of the actual vertical line can be grasped. Next, the difference (Δx1, Δx2, Δx3) between the actual vertical line position (solid line) and the ideal vertical line position (dotted line) is measured. The difference (Δx1) between the second actual vertical line position and the ideal vertical line position can be obtained by Δx1 = x1−α. The difference (Δx2) between the position of the third actual vertical line and the ideal vertical line position can be obtained by Δx2 = x2-2α. In addition, the difference (Δx3) between the position of the third actual vertical line and the ideal vertical line position can be obtained by Δx3 = x3−3α. Based on this difference (Δx1, Δx2, Δx3), the positional deviation in the main scanning direction is corrected, and the position of the vertical line (solid line) actually recorded on the recording medium 16 is the ideal vertical line (dotted line). Correct the position.

  Further, when measuring the relative positional deviation of the recording head 6 on the downstream side in the main scanning direction, the method shown in FIG. 15 described above is used. However, the position of the first black vertical line recorded on the leftmost side may deviate from the position of the main scanning position deviation measurement reference line as shown in FIG. Therefore, the difference (Δx0) between the position of the first black vertical line recorded on the leftmost side and the position of the reference line for main scanning positional deviation measurement is obtained, and the difference (Δx0) is recorded on the leftmost side. After correcting the position of the first black vertical line to the position (ideal position) of the reference line for measuring the main scanning position deviation, the main scanning of the recording head 6 on the downstream side is performed using the method shown in FIG. The relative displacement in the direction is measured, and the displacement in the main scanning direction is corrected.

  Further, when measuring the deviation in the sub-scanning direction between the upstream recording head 6 and the downstream recording head 6, the lower two horizontal lines of the four horizontal lines shown in FIG. Recording is performed on the recording medium 16 using the recording head 6 on the side. Also, the upper two horizontal lines are recorded on the recording medium 16 by using the downstream recording head 6. Then, as shown in FIG. 17, the distances (β1, β2) between the horizontal lines are measured, and the difference (Δβ = β1-β2) is calculated between the upstream recording head 6 and the downstream recording head 6. Is calculated as the amount of positional deviation in the sub-scanning direction. Based on this difference (Δβ), the positional deviation in the sub-scanning direction between the upstream recording head 6 and the downstream recording head 6 is corrected, and the distances (β1, β2) between the horizontal lines are the same. Correct so that

  Since the sub-scanning distance reference line and the main scanning distance reference line constituting the reference chart 400 are absolute distances, the absolute distance between the sub-scanning distance reference line and the main scanning reference line is previously stored in the storage unit 120. 14, the imaging distance between the sub-scanning distance reference line and the main scanning distance reference line shown in FIG. 14 obtained by imaging the reference chart 400, and the sub-scanning distance reference line and the main scanning distance managed by the storage unit 120. By comparing the absolute distance with the reference line, calculating the relative ratio between the imaging distance and the absolute distance, and multiplying the positional deviation amount obtained from the test pattern 100 of the subject imaging area described above by the relative ratio, The actual positional deviation amount can be calculated. By performing the positional deviation correction based on the actual positional deviation amount, highly accurate positional deviation correction can be performed.

  The control unit 107 performs the above-described misregistration amount calculation processing based on the captured image shown in FIG. 14 captured by the imaging unit 42, and discharges from the recording head 6 based on the misregistration amount calculated by the calculation processing. The ink ejection timing is controlled, the transport amount of the recording medium 16 is controlled, and the position of the image formed by the ink ejected from the recording head 6 is corrected. Thereby, it is possible to eliminate the positional deviation of the image and perform the color measurement of the test pattern 100 with high accuracy.

  In the above-described misalignment correction method example, the test pattern 100 is configured using a line pattern as shown in FIG. However, it is also possible to configure a test pattern 100 using a dot pattern as shown in FIG.

  In the case of the test pattern 100 shown in FIG. 18, the amount of positional deviation of the upstream recording head 6 in the main scanning / sub-scanning direction is measured using the dots in the first frame 301. Further, the positional deviation amount of the downstream recording head 6 in the main scanning / sub-scanning direction is measured using the dots in the second frame 302. Further, the amount of positional deviation in the main scanning / sub scanning direction between the upstream recording head 6 and the downstream recording head 6 is measured using the dots in the third frame 303. Further, the amount of positional deviation of the recording head 6 in the main scanning and sub-scanning directions due to the reciprocation of the carriage 5 is measured using the dots in the fourth frame 304.

<Operation / Effect of Recording Apparatus of this Embodiment>
As described above, the recording apparatus of the present embodiment records the test pattern 100 that is a color measurement target on the recording medium 16, and the test pattern 100 that is the color measurement target and the reference chart 400 that is arranged in the imaging unit 42. Are simultaneously captured by the imaging unit. Then, based on the captured image captured by the imaging unit 42, the color of the reference chart 400 is compared with the color of the test pattern 100, and the color of the test pattern 100 is measured. Thereby, it can be used even when the imaging unit 42 moves, is inexpensive, and can improve the colorimetric accuracy of the test pattern 100.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, the series of processing operations of the above-described embodiment need not be performed by only one control unit 107, but can be configured to be performed by a plurality of control units.

  Further, the control operation of each unit constituting the recording apparatus of the present embodiment described above can be executed using hardware, software, or a combined configuration of both.

  In the case of executing processing using software, it is possible to install and execute a program in which a processing sequence is recorded in a memory in a computer incorporated in dedicated hardware. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

  For example, the program can be recorded in advance on a hard disk or ROM (Read Only Memory) as a recording medium. Alternatively, the program can be stored (recorded) temporarily or permanently in a removable recording medium. Such a removable recording medium can be provided as so-called package software. Examples of the removable recording medium include a floppy (registered trademark) disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disk, a DVD (Digital Versatile Disc), a magnetic disk, and a semiconductor memory.

  The program is installed in the computer from the removable recording medium as described above. In addition, it is wirelessly transferred from the download site to the computer. In addition, it is transferred to the computer via a network by wire.

  The recording apparatus according to the present embodiment is not only executed in time series according to the processing operation described in the above embodiment, but also the processing capability of the apparatus that executes the process, or in parallel or individually as required. It is also possible to build to run on

5 Carriage 6 Recording Head 16 Recording Medium 100 Test Pattern 200 Platen Plate 400 Reference Chart 40 Encoder Sheet 41 Encoder Sensor 42 Imaging Unit (Imaging Device)
421 Case 423 Two-dimensional sensor 424 Light source 425 Imaging lens 426 Reflective member 427 Support member 428 Opening 429 Partially bendable case 107 Control unit 109 Main scanning driver 111 Recording head driver 112 Paper transport unit 113 Sub-scan driver 118 ROM
119 RAM
120 storage unit

Japanese Patent No. 3129502

Claims (7)

A recording device having a recording means and an imaging device,
The recording means records a test pattern on a recording medium using a recording agent,
The imaging device
A housing having an opening in the first wall, a second wall facing the first wall, and a side wall connecting the first wall and the second wall. Body,
A reference pattern composed of a plurality of color patches and disposed on the side wall;
A two-dimensional sensor that images the test pattern through the opening in a part of the imaging region and images the reference pattern in the other region;
The two-dimensional sensor, and an imaging element that is disposed on an optical path of the reference pattern and the test pattern and forms an image of the reference pattern on a sensor surface of the two-dimensional sensor;
A reflecting member that is disposed in an optical path between the two-dimensional sensor and the reference pattern, and that matches an imaging position of the image of the test pattern and an imaging position of the image of the reference pattern;
With
The amount of the recording agent used for recording by at least the recording unit changes based on the image data of the plurality of color patches in the captured image data captured by the two-dimensional sensor and the image data of the test pattern. A recording apparatus. A light source for irradiating light to the reference pattern and the test pattern;
The recording apparatus according to claim 1, wherein the two-dimensional sensor images simultaneously the reference pattern and the test pattern irradiated with light from the light source.   A support member that supports the reflection member at a predetermined angle is disposed in the housing, and the image formation position of the test pattern and the reference pattern are formed by the reflection member that is disposed on the support member at a predetermined angle. The recording apparatus according to claim 1, wherein the image forming position is matched.   Of the casings, a part of the casing on the test pattern side can be bent steplessly, and the test is performed by the reflecting member disposed or formed on the part of the casings bent at a predetermined angle. The recording apparatus according to claim 1, wherein an image forming position of the pattern is matched with an image forming position of the reference pattern.   The colorimetric means for performing colorimetry of the test pattern using image data of the plurality of color patches in the captured image data captured by the two-dimensional sensor. The recording device described in 1.   The recording apparatus according to claim 5, wherein the color measurement unit outputs a Lab value as a color measurement value.   The recording apparatus according to claim 1, wherein the imaging apparatus is mounted on a carriage.

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