JP2014190796A - Color measuring instrument and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color measuring instrument and a printer capable of accurately performing color measurement.SOLUTION: A color measuring instrument includes; conveyance means for conveying a medium M in which a plurality of measurement patterns are formed in a conveyance direction; measurement means for measuring each measurement pattern on the medium M; and control means for, when the measurement result is kept within a first range, allowing the conveyance means to convey the medium only by a first feed amount, and for allowing the measurement means to measure the measurement pattern as the next measurement object, and for, when the measurement result is not kept within the first range, allowing the conveyance means to convey the medium only by a feed amount different from the first feed amount, and for allowing the measurement means to measure the measurement pattern as the next measurement object.

Description

  The present invention relates to a colorimeter that measures an object.

  2. Description of the Related Art Conventionally, a colorimeter including a measuring unit that measures color information of a medium and a conveying unit that conveys a medium is known. In the colorimetry of the colorimeter, first, the conveyance unit conveys the medium to the measurement range of the measurement unit, and the measurement unit measures color information such as patterns and color charts formed on the medium. Then, the colorimeter acquires a colorimetric value based on the measurement result.

  The conveyance of the medium by the conveyance means may cause a positional deviation due to various factors. For this reason, an invention is disclosed in which a positional deviation due to the conveyance of the conveying means is detected before the colorimetric processing and this deviation is corrected. Specifically, a pair of marks is formed before and after the color chart conveyance direction on the medium. Then, before the color measurement process, the medium is conveyed and a pair of marks is measured to detect the feeding state of the medium (for example, see Patent Document 1).

JP 2011-26045 A

  In order to increase the accuracy of colorimetry, it is preferable to correct the positional deviation caused by transporting the medium. However, in the configuration in which the positional deviation is detected before the color measurement process, the time required for color measurement may be long. Further, since a region for forming a pair of marks is required before and after the color chart conveyance direction on the medium, the medium has to be used extra.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a colorimeter and a printer capable of accurately performing colorimetry.

  In order to solve the above problems, in the present invention, first, the transport unit transports a medium in which a plurality of measurement patterns are formed in the transport direction in the transport direction. Next, the measurement unit acquires each measurement pattern on the medium transported by the transport unit. Next, when the measurement result falls within the first range, the control unit causes the conveyance unit to convey the medium by the first feed amount, and causes the measurement unit to measure the measurement pattern to be measured next. On the other hand, if the measurement result does not fall within the first range, the control unit causes the transport unit to transport the medium by a second feed amount different from the first feed amount, and causes the measurement unit to be the next measurement target. The measurement pattern is measured.

  Therefore, when the measurement result falls within the first range, the medium feed amount for measuring the next measurement pattern becomes the first feed amount. On the other hand, when the measurement result does not fall within the first range, the medium feed amount for measuring the next measurement pattern becomes the second feed amount. That is, the result of measuring the measurement pattern is reflected in the feed amount for measuring the next measurement pattern, so that the feed amount is adjusted to an appropriate amount for each measurement. As a result, the position of the medium by the conveyance becomes appropriate, and the feed amount can be corrected without detecting the deviation due to the conveyance before the time, and the time required for the color measurement can be shortened.

Here, the object to be measured by the measuring means may be any object as long as the shape or color constituting the measurement pattern can be measured quantitatively. For example, spectral reflectance indicating the intensity of reflected light, brightness, value in L * a * b * color space defined by the International Commission on Illumination (CIE), value in L * u * v * color space, CIE It may be a value in a prescribed XYZ color space, a value in an RGB color space, or the like.
The measurement result used by the control unit includes a case where the measurement value of the measurement unit is used as it is, or a case where the control unit acquires an index value or the like based on the measurement value and uses this index value as the measurement result.

The control means may be configured to set the second feed amount based on the measurement result.
In the invention configured as described above, since the second feed amount is changed based on the measurement result, the medium can be conveyed with high accuracy.

The configuration of the measurement pattern may be anything as long as the measurement value changes. Therefore, the measurement pattern is located at any one of the first region configured so that the measurement result falls within the first range, and at least upstream and downstream in the transport direction with respect to the first region, It is good also as a structure containing the 2nd area | region comprised so that the said measurement result may not fit in the said 1st range.
In the invention configured as described above, since the measurement result changes according to the relative positional relationship between the measurement unit and the measurement pattern, the control unit can grasp the shift amount of the feed amount from the measurement result. Become.

Furthermore, as an example of a specific configuration of the measurement pattern, the first region and the second region may be configured such that the measurement results have different saturations.
In the invention configured as described above, it is possible to grasp the relative positional shift amount between the measurement unit and the measurement pattern based on the change in saturation.

The first range may be a value set according to the color of the background of the medium.
In the invention configured as described above, it is possible to set the feed amount reflecting the color of the background of the medium.

The medium is formed such that a plurality of color charts from which color information is acquired are arranged in the transport direction, and the measurement pattern and the color chart have the same position in the transport direction. It may be arranged.
In the invention configured as described above, by arranging the measurement pattern at the same position in the color chart and the conveyance direction, the size of the measurement target formed on the medium can be set upstream or downstream in the color chart conveyance direction. It can be made smaller than the case where it is arranged.

  The present invention can also be applied to a printer having such a colorimeter.

It is a figure explaining the colorimeter of this invention. FIG. 2 is a block configuration diagram illustrating a configuration of a printer. The color chart which a printer prints is illustrated. FIG. 6 is a diagram illustrating color measurement processing executed by a printer. 6 is a flowchart illustrating color measurement processing executed by a printer. It is a flowchart which shows the process performed in FIG.5 S12. It is a figure explaining the relationship between a colorimetric value and a correction amount. It is a figure explaining the relationship between a colorimetric value and a correction amount. It is a figure which shows the color chart which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in the following order.
1. First embodiment:
2. Second embodiment:
3. Other embodiments:

1. First embodiment:
FIG. 1 is a diagram illustrating a colorimeter according to the present invention. FIG. 2 is a block diagram illustrating the configuration of the printer.

  In the present embodiment, the colorimeter is configured as a part of the printer. Therefore, the printer 20 is a printer with a color measurement unit that has not only a printing function on the paper (medium) M but also a color measurement function that measures the color of the printed matter printed on the paper M.

  As shown in FIG. 2, the printer 20 is connected to a printer control IC 21, a communication I / F 22, a color measurement unit 10, and the like via a bus. The printer 20 is connected to the computer 100 through the communication I / F 22. Therefore, the printer 20 can communicate with the computer 100.

  Further, as shown in FIG. 1, the printer 20 can accommodate a sheet M wound in a roll shape (not shown) in the casing, and conveys one end of the sheet M in the conveyance direction D1. On the path of the paper M, a print head 21a is installed. The print head 21a moves along a guide rail (not shown) in a direction perpendicular to the transport direction D1 (scanning direction D2). A colorimetric unit 10 is installed on the downstream side of the sheet conveyance path.

  When the paper M is conveyed, it passes under the print head 21a and the color measurement unit 10, respectively. Therefore, the print head 21a prints the color chart 30 on the conveyed paper M. Then, the color measuring unit 10 measures the color chart 30 printed by the print head 21a.

  As shown in FIG. 2, the printer control IC 21 is an IC that mainly executes various controls for print processing, and includes a CPU, a ROM, and a RAM (not shown). The printer control IC 21 is connected to a print head 21a, a head drive unit 21b, a carriage mechanism 21c, and a paper feed mechanism 21d.

The print head 21a has a plurality of ink cartridges corresponding to a plurality of ink types (for example, cyan (C), magenta (M), yellow (Y), black (K), etc.), and each ink type. And a plurality of nozzle rows provided. Then, the print head 21 a forms the color chart 30 on the paper M by ejecting ink filled in the ink cartridge as ink droplets from the nozzle row. The head drive unit 21b generates and outputs a voltage pattern (drive waveform) applied to the piezoelectric elements built in each nozzle row of the print head 21a, and causes the print head 21a to eject ink droplets (dots) for each ink type. .
The printer 20 may be a printer that forms a print image by another mechanism such as a thermal type or a sublimation type, or a line head type printer.

  The carriage mechanism 21 c is a drive device that reciprocates a carriage (not shown) along a guide rail (not shown) provided in the printer 20. A print head 21a is mounted on the carriage, and the print head 21a reciprocates (scans) along the guide rail.

  The paper feed mechanism 21d includes a stepping motor and a paper feed roller that is rotated by the stepping motor. Then, the paper feed mechanism 21d feeds the paper M by a predetermined feed amount in the transport direction D1. Here, the feed amount is an amount corresponding to the rotation speed of the stepping motor. The feed amount can be adjusted according to a step signal output from the printer control IC 21. Therefore, the paper feed mechanism 21d implements the transport unit of the present invention.

  Note that the feed amount in the printing process is constant unlike the feed amount in the color measurement process. Also, the direction of the feed amount may differ between the printing process and the color measurement process. Therefore, in the following, the feeding amount at the time of the printing process is distinguished as PF, and the feeding amount at the time of the color measurement processing is distinguished as CF.

  The color measurement unit 10 measures the color chart 30 printed on the paper M by the print head 21a. The color measurement unit 10 includes a color measurement control IC (control unit) 11, a measurement unit (measurement unit) 12, a measurement unit moving mechanism 13, and a dryer 14.

  The color measurement control IC 11 is an IC that mainly executes various controls for color measurement processing, and is connected to each unit of the measurement unit 12, the measurement unit moving mechanism 13, and the dryer 14 to control each unit. Further, the colorimetric value can be acquired based on the spectral reflectance output from the measuring unit 12.

  The measurement unit 12 can acquire the spectral reflectance of the paper M by directing the aperture toward the color measurement target. The spectral reflectance acquired by the measuring unit 12 is output to the colorimetry control IC 11 and a plurality of color components L *, a based on the L * a * b * color system defined by the International Commission on Illumination (CIE). Converted to *, b * (colorimetric value). The color component value is output to the computer 100. The measuring unit 12 can be reciprocated in the scanning direction D2 by the measuring unit moving mechanism 13.

  Hereinafter, the spectral reflectance acquired by the measurement unit 12 is also simply referred to as color information. The color information may be a value other than the spectral reflectance. Moreover, the measurement part 12 may acquire a colorimetric value directly. The colorimetric values may be values such as CIE-defined L * u * v * color space, CIE-defined XYZ color space, and RGB color space.

  FIG. 3 illustrates a color chart 30 printed by the printer 20. The color chart 30 is composed of a plurality of chart rows n (n is an integer from 1 to N) arranged in the transport direction D1. One chart row n includes a feed amount correction patch 31 and a colorimetric patch 40. In FIG. 3, the first column of the chart row n is configured as a feed amount correction patch 31, and the second and subsequent columns are configured as colorimetric patches 40.

  In the first embodiment, the feed amount correction patch 31 and the color measurement patch 40 are included in all chart rows n, but the configuration of the color chart 30 is not limited to this. For example, the feed amount correction patch 31 may be included in every predetermined chart row n.

  The colorimetric patch 40 is printed on the printer 20 so that each patch (color chart) composed of a solid pattern is arranged in the scanning direction D2 in one chart row n. The color information that can be acquired by each colorimetric patch 40 is different. In FIG. 3, all the colorimetric patches 40 are expressed in white, but it goes without saying that each patch is actually printed in a different color.

  The feed amount correction patch 31 sets a feed amount CF at which the paper feed mechanism 21d feeds the paper M during the colorimetric processing. Since the feed amount correction patch 31 is included in each chart row n, a plurality of patches are printed on the printer 20 so as to be provided side by side in the transport direction D1. In the first embodiment, each feed amount correction patch 31 includes adjustment patterns 32, 33, and 34 formed from chart row 1 to chart row 3, and measurement pattern formed from chart row 4 to chart row N. 35.

  In addition, the measurement pattern 35 includes a first area 36, and a second area 37 and a third area 38 that are positioned before and after the first area 36 in the transport direction D <b> 1. In the first embodiment, the size of the first region 36 in the transport direction D1 is larger than the diameter that defines the measurement range R of the measurement unit 12, and no dots are formed. Therefore, when the measurement unit 12 measures the color of the first region 36, color information corresponding to the background of the paper M is acquired. Further, the center in the transport direction D1 of the first region 36 coincides with the center in the transport direction of the colorimetric patch 40 belonging to the same chart row n (position indicated by a one-dot chain line in the drawing).

  Further, the second area 37 and the third area 38 are configured to have a color measurement result different from that of the first area 36. In the first embodiment, the second region 37 is composed of magenta (M) dots. The third area 38 is composed of cyan (C) dots. The second area 37 and the third area 38 are configured such that the color information changes as the distance from the first area 36 increases in the transport direction D1. In FIG. 3, the portion 37a on the first region side of the second region 37 is configured such that the saturation a * acquired in accordance with the color information is lower than that of the portion 37b. Similarly, the portion 38a on the first region side of the third region 38 is configured so that the saturation a * acquired in accordance with the color information is higher than that of the portion 38b.

  Using the first area 36 as the background of the paper M is merely an example, and the second area 37 and the third area 38 may be formed with dots of different colors. The second area 37 and the third area 38 may be configured to have different color measurement results. Therefore, forming the second region 37 with magenta (M) dots and forming the third region 38 with cyan (C) dots is merely an example. Further, the measurement pattern 35 may include either the second region 37 or the third region 38.

  In the adjustment pattern 32, dots are formed so as to have the same color information as the first region 36 of the measurement pattern 35. That is, in the first embodiment, the adjustment pattern 32 is an area where no dots are formed. The adjustment pattern 33 is formed with dots so as to have the same color information as the portion 37 b of the second region 37 of the measurement pattern 35. That is, the adjustment pattern 33 is formed by a solid pattern recorded with magenta (M) dots. In the adjustment pattern 34, dots are formed so as to have the same color information as the portion 38 b of the second region 37 of the measurement pattern 35. That is, the adjustment pattern 34 is formed by a solid pattern recorded with cyan (C) dots.

  The feed amount correction patch 31 includes the adjustment patterns 32, 33, and 34 as an example. Therefore, the feed amount correction patch 31 may not include the adjustment patterns 32, 33, and 34. Further, the feed amount correction patch 31 may include any of the adjustment patterns.

  Next, a color chart printing process and a color measurement process executed by the printer 20 will be described. FIG. 4 is a diagram for describing color measurement processing executed by the printer 20.

  In the color measurement process described below, the direction of the feed amount CF of the paper M executed by the paper feed mechanism 21d is the same as that of the feed amount PF of the paper M performed by the printing process, and the direction is reversed. There are cases (FIG. 3). In the present embodiment, an example will be described in which the direction of the feed amount CF of the color measurement process is opposite to the direction of the feed amount PF of the printing process (so-called back feed). Therefore, in the color measurement process, color measurement is performed in order from the chart row 1. Of course, the feed amount PF of the printing process and the feed amount CF of the color measurement process may be in the same direction.

First, the printer 20 acquires job data GD for printing the color chart 30 from the computer 100.
This job data GD includes halftone data. The halftone data is data that defines the ejection / non-ejection of dots for each pixel and for each ink type by a halftone process using a known method such as a dither method or an error diffusion method. The computer 100 performs a predetermined rasterization process on the halftone data, rearranges them in the order in which the printer 20 prints, and outputs the data to the printer 20 for each ink type. As a result, the printer 20 controls the print head 21a, the head drive unit 21b, the carriage mechanism 21c, and the paper feed mechanism 21d under the control of the printer control IC 21, and prints a color chart on the paper M based on the job data GD. .

  Then, when the printing of the last chart row of the color chart 30 (chart row 1 in the present embodiment) is completed, the printer 20 starts the color measurement of the color chart 30. In the color measurement process executed by the printer 20, the printer 20 moves the measurement unit 12 in the scanning direction D <b> 2 and measures all the patches included in one chart row n of the color chart 30. When the color measurement for one chart row m is completed, the sheet M is sent in the transport direction D1 by the feed amount CF, and the color of the next chart row m + 1 is measured.

  At this time, the actual feed amount CF of the paper feed mechanism 21d may not be constant due to various factors, and the position of the patch after paper feed may not be an appropriate position in the measurement range R. In FIG. 4A, the measurement range R (region indicated by a circle) in the chart row m is deviated from the center indicated by the dotted line of the patch. Therefore, when the sheet M is fed with the feed amount CFs as it is, the measurement range R of the chart row m + 1 is not positioned at the center indicated by the dotted line of the patch. Here, the feed amount CFs indicates the feed amount of the paper feed mechanism 21d when correction is not performed.

  Therefore, in the first embodiment, the printer 20 sets the feed amount CF for measuring the next chart row m + 1 based on the result obtained by measuring the feed amount correction patch 31. In FIG. 4B, the feed amount CFd obtained by measuring the feed amount correction patch 31 in the chart row m is different from the reference feed amount CFs (first feed amount). As a result, the measurement range R for measuring the color of the chart row m + 1 is located at the center of the color chart. That is, for each color measurement of each chart row, since the feed amount CF for moving the next color measurement target chart row to the measurement range R is set, the patch is arranged at an appropriate position in the measurement range R. Can do. As a result, the color measurement accuracy can be increased.

  FIG. 5 is a flowchart for explaining the colorimetric processing executed by the printer 20. FIG. 6 is a flowchart showing the process executed in step S12 of FIG. 7 and 8 are diagrams for explaining the relationship between the colorimetric value and the correction amount.

  First, in step S <b> 11 of FIG. 5, the color measurement control IC 11 feeds the paper M so that the color chart moves to below the measurement range R of the measurement unit 12. Specifically, the printer control IC 21 that has input a conveyance instruction from the colorimetric control IC 11 controls the paper feed mechanism 21 d so that the chart row 1 falls within the measurement range R by the measurement unit 12. Is transported for the required distance.

  Next, in step S12, prior to setting the feed amount CF, the correspondence relationship between the colorimetric value and the correction amount is updated (step S12). For example, when the background color changes due to different materials or the like of the paper M, the color information acquired by the measurement unit 12 also changes. When the spectral reflectance changes, the colorimetric values acquired by the colorimetry control IC 11 also become different values. Therefore, processing for reflecting the color information of the patch is performed so that the feed amount CF is correctly acquired from the colorimetric values corresponding to the measurement pattern 35.

  First, in step S <b> 121 of FIG. 6, the colorimetry control IC 11 acquires the colorimetric values of the patches belonging to the chart row 1 including the adjustment pattern 32. Therefore, the colorimetric control IC 11 moves the measuring unit 12 in the scanning direction D2 and acquires color information for each patch constituting the chart row 1. Then, colorimetric values (L *, a *, b *) are sequentially obtained from this color information.

  In step S122, the colorimetry control IC 11 takes out the colorimetric values of the adjustment pattern 32. Therefore, the colorimetry control IC 11 acquires the saturation a * corresponding to the first region 36. In step S <b> 123, the colorimetric control IC 11 transmits the colorimetric values corresponding to the colorimetric patches 40 included in the chart row 1 to the computer 100.

  Since the colorimetry control IC 11 has not measured the color of all chart rows n including the adjustment patterns 31 to 33 (step S124: NO), the colorimetry control IC 11 causes the paper feed mechanism 21d to feed the paper M. (Step S125). Therefore, the paper feed mechanism 21d feeds the paper M by the feed amount CFs, and positions the measurement range R of the measurement unit 12 in the chart row 2.

  In step S121, the color measurement control IC 11 causes the measurement unit 12 to measure a patch belonging to the chart row 2 including the adjustment pattern 33, and obtains a color measurement value from the measurement result.

  In step S122, the colorimetry control IC 11 takes out the colorimetric values of the adjustment pattern 33. For this reason, the colorimetry control IC 11 acquires the saturation a * of the second region 37. In step S123, the color measurement control IC 11 transmits the color measurement values of the color measurement patches 40 included in the chart row 2 to the computer 100.

  Thereafter, the colorimetric control IC 11 performs the same process for the chart row 3 (steps S121 to S123). Therefore, the colorimetry control IC 11 acquires the saturation a * of the third area 38.

  Since all the chart rows n including the adjustment patterns 31 to 33 are measured (step S124: YES), in steps S126 to S129, the colorimetry control IC 11 determines the colorimetric value and the correction amount V recorded in advance. Update the relationship. For example, the colorimetry control IC 11 records a table T that records the relationship between the colorimetric value (saturation a *) and the correction amount V as shown in FIG. The relationship between the saturation a * and the correction amount V is updated so as to correspond to the actual colorimetric result. Here, the output value (correction amount V) of the table T is recorded such that the correction amount V increases as the input value (saturation a *) increases.

  Specifically, in step S126, the colorimetry control IC 11 sets the saturation a * of the adjustment pattern 32 as the reference value D1, and the correction amount V recorded in the table T based on the reference value D1 is 0. Update the range of saturation a *. Here, FIG. 7B shows the relationship between the values in the table T before the update, and FIG. 7C shows the relationship between the values in the table T after the update. The reference value D1 is saturation a * corresponding to the first region 36 of the measurement pattern 35. When the saturation a * is near the reference value D1, the correction amount V is 0 (that is, the feed amount CF is corrected). It is desirable that Therefore, the colorimetry control IC 11 updates the range (first range) of the saturation a * in which the feed amount CF is not corrected around the reference value D1.

  In step S127, the colorimetry control IC 11 sets the saturation a * of the adjustment pattern 33 as the reference value D2, and based on this reference value D2, the saturation a corresponding to the upper limit of the correction amount V of the table T. The maximum value of * (saturation a * max) is updated. Since the reference value D2 is the saturation a * corresponding to the maximum value of the second region 37 of the measurement pattern 35, the saturation a * never exceeds the reference value D2 within one measurement pattern 35. . The saturation a * max is a value associated with an upper limit value (Vmax) of a correction amount V (hereinafter also referred to as a positive correction value V) that increases the feed amount CF (FIG. 7B). ), FIG. 7 (c)).

  In step S128, the colorimetry control IC 11 sets the saturation a * of the adjustment pattern 34 as the reference value D3, and the saturation a corresponding to the lower limit of the correction amount V of the table T based on the reference value D3. The minimum value of * (saturation a * min) is updated. Since the reference value D3 is the saturation a * corresponding to the minimum value of the third region 38 of the measurement pattern 35, the saturation a * never falls below the reference value D3 within one measurement pattern 35. . The saturation a * min is a value associated with an upper limit value (Vmin) of a correction amount V (hereinafter also referred to as a minus side correction amount V) that decreases the feed amount CF (FIG. 7 ( b), FIG. 7 (c)).

  In step S129, all the relationships between the input values and output values recorded in the table T are updated according to the acquired values of the reference values D1 to D3.

  Next, returning to FIG. 5, in Steps S21 to S27, the colorimetry control IC 11 sets the feed amount CF based on the updated table T and the saturation a * of the measurement pattern 35.

In step S21, the colorimetry control IC 11 causes the measurement unit 12 to measure the chart row k including the measurement pattern 35, and obtains the colorimetric values of the respective patches. In the first embodiment, k is an integer starting from 4. As described above, the measurement unit 12 acquires the color information of each patch included in the chart row k while moving in the scanning direction D2. Then, the colorimetric control IC 11 calculates colorimetric values (L *, a *, b *) based on this color information.
In step S <b> 22, the color measurement control IC 11 transmits the color measurement values of the color measurement patches 40 included in the chart row k to the computer 100.

  In step S23, since the chart row to be colorimetric is not the last row (step S23: NO), in step S24, the colorimetry control IC 11 extracts the saturation a * of the measurement pattern 35 acquired in step S21.

  If the saturation a * of the measurement pattern 35 is within the measurement range (step S25: YES), the colorimetry control IC 11 proceeds to step S26. On the other hand, when the saturation a * of the measurement pattern 35 is out of the measurement range (step S25: NO), the colorimetry control IC 11 displays an error (step S28). Since the saturation a * of the measurement pattern 35 is a value within the range defined by the saturation a * max and the saturation a * min, the colorimetry control IC 11 determines that the saturation a * exceeds this range. The color measurement result is judged to be an error.

In step S26, the colorimetry control IC 11 acquires a correction amount V corresponding to the saturation a * of the measurement pattern 35 extracted in step S21.
Therefore, as shown in FIG. 8A, when the measurement range R of the measurement unit 12 measures only the first region 36, the color information includes only the background color (saturation a * = 0) of the paper M. Including. Therefore, the correction amount V acquired from the table T is “0”, and the colorimetry control IC 11 does not acquire the correction amount V.

  Further, as shown in FIG. 8B, when the measurement range R of the measurement unit 12 is shifted to the second region 37 side compared to the first region 36, the color information meter component includes magenta (M). It becomes like this. Therefore, the saturation a * increases compared to the first reference value D1. The second region 37 is configured such that the saturation a * increases as the distance from the first region 36 increases, and the saturation a * increases as the displacement of the measurement range R toward the second region 37 increases. Increases (FIG. 8 (c)). Therefore, the correction amount V becomes the plus side correction amount V corresponding to the increase in the saturation a *.

  On the other hand, as shown in FIG. 8D, when the measurement range R is shifted to the third region side 38 compared to the first region 36, the color information component includes cyan (C). Therefore, the saturation a * decreases compared to the reference value D1. The third region 38 is configured such that the saturation a * decreases as the distance from the first region 36 increases, and the saturation a * increases as the shift toward the third region 38 in the measurement range R increases. Decreases (FIG. 8 (e)). Therefore, the correction amount V becomes the minus side correction amount V corresponding to the decrease in the value of the saturation a *.

  When the direction of the feed amount CF of the color measurement process is the same as the direction of the feed amount PF of the printing process, the correction amount V is opposite to the above example. That is, the correction amount V increases as the saturation a * of the measurement pattern 35 increases, and the correction amount V decreases as the saturation a * of the measurement pattern 35 decreases.

  In step S27, the colorimetry control IC 11 corrects the reference feed amount CFs using the acquired correction amount V, and causes the paper feed mechanism 21d to feed the paper M using the corrected feed amount CFd. For example, when the measurement range R of the measurement unit 12 is shifted in the direction of the second region 37, the feed amount CFd of the paper feed mechanism 21d is longer than the reference feed amount CFs. On the other hand, when the measurement range R of the measurement unit 12 is shifted in the direction of the third region 38, the feed amount CFd of the paper feed mechanism 21d is shorter than the reference feed amount CFs. Therefore, the paper is fed so that the center of the first region 36 is positioned at the center of the measurement range R of the measurement unit 12.

  Then, returning to step S21, the color measurement control IC 11 measures the corresponding chart row k + 1 of the color chart 30 after the paper is fed by the feed amount CFd. Colorimetric values are also acquired for the measurement pattern 35 included in the chart row k + 1.

  Hereinafter, the color measurement unit 10 repeats the processes of steps S21 to S27 until all the chart rows n are measured (step S23). Then, when the colorimetric unit 10 performs colorimetry on the chart row N of the color chart 30 (step S22: YES), the colorimetry process ends.

  As described above, in the first embodiment, when the measurement result falls within the first range, the sheet feed amount for measuring the next measurement pattern is the reference feed amount CFs, and the measurement result is the first. If it does not fall within this range, the sheet feed amount for measuring the next measurement pattern is a feed amount CFd different from the reference feed amount CFs. That is, the measurement result of the measurement pattern is reflected in the feed amount CF for moving the measurement pattern to be measured next to the measurement range, so that the feed amount CF is changed every measurement. As a result, the time required for color measurement can be shortened compared to the case of detecting the shift of the feed amount in advance.

  Furthermore, according to the present invention, it is possible to accurately correct the deviation of the measurement position of the medium, so that the size of the colorimetric patch can be designed without taking the deviation of the feed amount into account. As a result, the size of the color chart can be reduced.

  Since the measurement result changes according to the relative positional relationship between the measurement range and the measurement pattern, the colorimetry control IC 11 can grasp the deviation of the feed amount CF from the measurement result. As a result, the colorimetry control IC 11 can correct the feed amount CF in detail.

  In addition, since the measurement pattern and each color measurement patch of the color chart are arranged at the same position in the conveyance direction D1, the measurement pattern is arranged upstream or downstream in the conveyance direction D1 of the color chart. Compared to the above, it is possible to reduce the sheet area required for colorimetry.

2. Second embodiment:
FIG. 9 is a diagram illustrating a color chart 30 according to the second embodiment. In the second embodiment, the configuration between the measurement patterns 35 arranged in the medium transport direction D1 is different from that in the first embodiment.

  As shown in FIG. 9, in the measurement pattern 35, the color arrangement between patterns arranged continuously in the transport direction D1 is a line target in the scanning direction D2. For example, the second area 37 of the chart row m and the third area 38 of the chart row m-1 are magenta (M), and the third area 38 of the chart row m and the second area 37 of the chart row m + 1 are Is cyan (C). Furthermore, the second area 37 included in the measurement pattern 35 is formed such that the saturation a * increases as the distance from the first area 36 increases in the transport direction D1. The third area 38 included in the measurement pattern 35 is formed such that the saturation a * decreases as the distance from the first area 36 increases in the transport direction D1.

  In the table T that defines the correspondence between the correction amount V and the colorimetric value, the maximum value Vmax of the correction amount V is not associated with the maximum value a * max of the saturation a *. It is associated with a * e1, which is smaller than a * max. In the table T, the minimum value Vmin of the correction amount V is not associated with the minimum value a * min of the saturation a *, and is associated with a * e2 that is larger than the minimum value a * min. ing.

  Therefore, when the measurement range R of the measurement unit 12 includes the third region 38 of the chart row m + 1 beyond the second region 37 of the chart row m, the value of the saturation a * acquired by the color measurement unit 10 is Maintain around a degree a * max. As described above, the maximum value a * max is not associated with the correction amount V in the table T, and error determination is performed in step S25 of the flowchart shown in FIG. An error can be displayed with respect to the positional deviation of the measurement range F across the measurement pattern 35.

  The invention according to the second embodiment configured as described above has the same effects as those of the first embodiment. Furthermore, even when the measurement range R includes a measurement pattern R that is adjacent to the measurement range R, such a positional deviation can be determined as an error.

3. Other embodiments:
There are various embodiments of the present invention.
The use of the printer 20 as an embodiment of the colorimeter is merely an example. For example, the present invention may be configured by a single colorimeter that realizes only the colorimetric function. The configuration of the feed amount correction patch 31 may be any configuration as long as the value changes according to the measurement position.
Further, the feed amount correction patch 31 may be included in every predetermined row, for example, every five rows, in addition to being included in all chart rows.
The use of paper as a medium is only an example. For example, color measurement can be performed using various media such as film paper and fabric.

Needless to say, the present invention is not limited to the above embodiments. That is,
The members and configurations that can be replaced with each other disclosed in the above embodiments may be applied by appropriately changing the combination thereof.
The members and configurations that are publicly known and can be mutually replaced with the members and configurations disclosed in the above-described embodiments may be appropriately replaced, and combinations thereof may be changed and applied.
-Based on publicly known techniques, those skilled in the art may appropriately replace the members and structures that can be assumed as substitutes for the members and structures disclosed in the above-described embodiments, and change the combinations thereof.

  DESCRIPTION OF SYMBOLS 10 ... Color measurement unit, 11 ... Color measurement control IC, 12 ... Measurement part, 13 ... Measurement part moving mechanism, 14 ... Dryer, 20 ... Printer, 21 ... Printer control IC, 21a ... Print head, 21b ... Head drive part , 21c ... carriage mechanism, 21d ... paper feed mechanism, 22 ... communication I / F, 30 ... color chart, 31 ... feed amount correction patch, 32, 33, 34 ... adjustment pattern, 35 ... measurement pattern, 36 ... first 1 area, 37 ... 2nd area, 38 ... 3rd area, 40 ... patch for colorimetry, 100 ... computer

Claims (7)

Transport means for transporting a medium in which a plurality of measurement patterns are formed in the transport direction in the transport direction;
Measuring means for measuring each measurement pattern on the medium;
When the measurement result falls within the first range, the transport unit transports the medium by the first feed amount, and causes the measurement unit to measure the measurement pattern to be measured next,
When the measurement result does not fall within the first range, the transport unit transports the medium by a second feed amount different from the first feed amount, and the measurement unit causes the measurement target to be the next measurement target. A colorimeter having a control means for measuring a measurement pattern.   The colorimeter according to claim 1, wherein the control unit sets the second feed amount based on the measurement result.   The measurement pattern is located at any one of the first area configured so that the measurement result falls within the first range, and at least upstream and downstream in the transport direction with respect to the first area. The colorimeter according to claim 1, further comprising: a second region configured so that a result does not fall within the first range.   The colorimeter according to claim 3, wherein the first area and the second area are configured such that the measurement results have different saturations.   5. The colorimeter according to claim 1, wherein the first range is a value set according to a color of a background of a medium. The medium is formed such that a plurality of color charts from which color information is acquired are arranged in the transport direction,
The colorimeter according to any one of claims 1 to 5, wherein the measurement pattern and the color chart are arranged so that positions in the transport direction are the same.   A printer having the colorimeter according to any one of claims 1 to 6.

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