JP2005195365A - White calibration method and 2-dimensional photometric system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a white calibration method and a 2-dimensional photometric system capable of inhibiting error caused by various unevenness between pixels in the same photometric device. <P>SOLUTION: The 2-dimensional photometric system is constituted such that; a white calibration plate measurement part 211 measures at least one or more time with a 2-dimensional area sensor 4 on the different places of the white calibration plate; a mean value calculation part 212 rejects pixel data indicating the output data caused by the defect of the white plate from the measured result of each time, then from the rejected measurement results the mean value of each pixel is calculated; a maker calibration value calculation part 215 calculates the maker calibration value for each pixel for whole pixels based on the mean value for each pixel; the white calibration plate measurement part 211 measures the white calibration plate with the 2-dimensional area sensor 4 only once; a user calibration value calculation part 216 calculates the user calculation value from the measurement results; and a white calibration coefficient calculation part 217 calculates the white calibration coefficient for each pixel based on the maker calibration value and the user calibration value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a white calibration method for a two-dimensional photometer using a white calibration plate and a two-dimensional photometry device.

  In general, a colorimeter, which is one of photometric devices (photometers), can obtain color information of a sample by incorporating various elements such as a sensor, a filter, a light source, and a light receiving optical system. Each element can cause performance errors in the manufacturing stage, no matter how careful it is. In addition, the arrangement method of each element, assembly error, and the like cause errors, and even if the same sample is measured, the finally obtained measurement value is affected as an absolute value error, an inter-photometer error, or the like.

Therefore, white calibration is conventionally performed in the colorimeter. In the white calibration, the error as described above is calibrated by measuring a white white calibration plate prior to the measurement of the sample. The white calibration is described in, for example, Patent Document 1 and Patent Document 2.
JP 7-270238 A Japanese Patent Laid-Open No. 7-55569

  By the way, the white calibration plate may not have a uniform reflectance due to defects such as black spots, pinholes, scratches, and unevenness. Even when a white calibration plate having defects is measured with a spot colorimeter using an SPD (Silicon Photo Diode) or the like, the defects are averaged with the surrounding normal parts, so that there is not much problem. However, in the case of a two-dimensional colorimeter that captures an image using an area sensor such as a CCD or CMOS, the correct white value is obtained for each pixel because the output value obtained for a certain pixel becomes extremely small due to a defect in the white calibration plate. It is difficult to obtain a calibration value.

  Therefore, in the conventional two-dimensional photometer, the average output value of the whole pixel or a part (for example, a predetermined range of the central portion) when the white calibration plate is measured, and the white calibration plate measured in advance by the reference device The white calibration value was calculated in comparison with the pricing value of, and the calculated white calibration value was used as a common white calibration value for all pixels. For this reason, it has been difficult to remove influences on measured values such as unevenness due to illumination, unevenness of sensitivity of the area sensor, and unevenness of the light receiving optical system.

  In other words, the average value of the entire screen can be correlated with the reference unit, and errors between photometers can be suppressed, but errors due to various unevenness between pixels of the same photometer can be suppressed. It was difficult.

  Alternatively, in a conventional two-dimensional photometer, the white calibration plate is ignored by ignoring the defect of the white calibration plate and comparing the output value of each pixel with the pricing value of the white calibration plate measured in advance by the reference device. The white calibration value calculated and different for each pixel was used. For this reason, the measurement value is affected by a defect of the white calibration plate, causing an error between pixels.

  Further, as a white calibration plate of a conventional two-dimensional photometer, a plate that does not easily cause defects in the manufacturing stage may be used. However, such a white calibration plate is very expensive, and the surface is easily scratched, so that it is difficult to use it with a contact-type photometer.

  The present invention has been made to solve the above-described problem. Even if a defect exists in the white calibration plate, the influence is minimized, and errors caused by various unevenness between pixels of the same photometer. It is an object of the present invention to provide a white calibration method and a two-dimensional photometric device that can suppress the above-mentioned problem.

  A white calibration method according to one configuration of the present invention includes a measurement step of measuring at least twice a different position of a white calibration plate serving as a calibration reference by a two-dimensional area sensor, and each measurement measured in the measurement step. Each pixel from the removal step of removing the pixel data indicating the output value due to the defect of the white calibration plate from the result, and the measurement result from which the pixel data indicating the output value due to the defect of the white calibration plate is removed in the removal step A pixel average calculation step for calculating an average value for each pixel, and a white calibration value calculation step for calculating a white calibration value for each pixel for the entire pixel based on the average value for each pixel calculated in the pixel average calculation step Including.

  According to this configuration, different positions of the white calibration plate serving as a calibration reference are measured at least twice by the two-dimensional area sensor, and an output value caused by a defect of the white calibration plate is obtained from each measured measurement result. The average value for each pixel is calculated from the measurement result from which the pixel data indicating is removed and the pixel data indicating the output value resulting from the defect of the white calibration plate is removed, and based on the calculated average value for each pixel The white calibration value for each pixel with respect to the entire pixel is calculated.

  Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. Can be obtained, and errors due to various unevenness between pixels of the same photometer can be suppressed.

  Further, in the white calibration method, the removing step removes pixel data indicating an output value caused by a defect of the white calibration plate from each measurement result measured in the measurement step, and removes other neighboring pixels. The output value is preferably the output value of the pixel.

  According to this configuration, the pixel data indicating the output value due to the defect of the white calibration plate is removed from each measurement result measured in the measurement step, and the output value of the other neighboring pixels becomes the output value of the pixel. Therefore, the defect of the white calibration plate can be removed, and an accurate average value for each pixel can be calculated.

  In the white calibration method, the white calibration value calculating step divides the price value of the white calibration plate measured in advance by the reference device by the average value for each pixel calculated in the pixel average calculating step. By doing so, it is preferable to calculate a white calibration value for each pixel.

  According to this configuration, the white calibration value for each pixel is obtained by dividing the pricing value of the white calibration plate measured in advance by the reference device by the average value for each pixel calculated in the pixel average calculation step. Since it is calculated, the white calibration value for each pixel can be calculated.

  A two-dimensional photometric apparatus according to another configuration of the present invention includes a measuring unit that measures a white calibration plate serving as a calibration reference by a two-dimensional area sensor, and at least two different positions of the white calibration plate by the measuring unit. From the measurement result, the removal means for removing the pixel data indicating the output value due to the defect of the white calibration plate, and the measurement result from which the pixel data indicating the output value due to the defect of the white calibration plate is removed by the removal means A pixel average calculation unit that calculates an average value for each pixel, and a white calibration value that calculates a white calibration value for each pixel for the entire pixel based on the average value for each pixel calculated by the pixel average calculation unit Calculating means.

  According to this configuration, the white calibration plate serving as a calibration reference is measured by the two-dimensional area sensor, and the output value resulting from the defect of the white calibration plate is shown from the result of measuring at least two different positions of the white calibration plate. The average value for each pixel is calculated from the measurement result in which the pixel data is removed and the pixel data indicating the output value due to the defect of the white calibration plate is removed, and based on the calculated average value for each pixel, A white calibration value for each pixel with respect to the entire pixel is calculated.

  Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. Can be obtained, and errors due to various unevenness between pixels of the same photometer can be suppressed.

  In the above two-dimensional photometry device, the sample measurement means for measuring the sample to be measured by the two-dimensional area sensor, and the measurement result measured by the sample measurement means are calculated by the white calibration value calculation means. It is preferable to further include correction means for correcting with the white calibration value for each pixel.

  According to this configuration, the sample to be measured is measured by the two-dimensional area sensor, and the measured measurement result is corrected by the calculated white calibration value for each pixel. Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. By correcting the measurement result obtained by measuring the sample with the white calibration value, accurate color information can be obtained.

  A white calibration method according to still another configuration of the present invention includes a first measurement step of measuring at least two different positions of a white calibration plate serving as a calibration reference by a two-dimensional area sensor, and the first measurement. A removal step of removing pixel data indicating an output value due to a defect of the white calibration plate from each measurement result measured in the step, and pixel data indicating an output value due to a defect of the white calibration plate in the removal step are A pixel average calculation step for calculating an average value for each pixel from the removed measurement result, and a calibration value for each pixel with respect to the entire pixel based on the average value for each pixel calculated in the pixel average calculation step. A calibration value calculation step to be calculated; a storage step for storing the calibration value calculated in the calibration value calculation step; A second measurement step that is measured only once by an acensus; an all-pixel average calculation step that calculates an average value of all pixels from a measurement result measured in the second measurement step; and a calibration that is stored in the storage step A white calibration value calculating step of calculating a white calibration value for each pixel based on the value and the average value of all the pixels calculated in the all pixel average calculating step.

  According to this configuration, different positions of the white calibration plate serving as a calibration reference are measured at least twice by the two-dimensional area sensor, and an output value caused by a defect of the white calibration plate is obtained from each measured measurement result. The average value for each pixel is calculated from the measurement result from which the pixel data indicating is removed and the pixel data indicating the output value resulting from the defect of the white calibration plate is removed, and based on the calculated average value for each pixel The calibration value for each pixel with respect to the entire pixel is calculated, and the calculated calibration value is stored. Then, the white calibration plate is measured only once by the two-dimensional area sensor, the average value of all the pixels is calculated from the measured result, and the stored calibration value and the calculated average value of all the pixels are used. Thus, a white calibration value for each pixel is calculated.

  Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. Can be obtained, and errors due to various unevenness between pixels of the same photometer can be suppressed.

  In the white calibration method, the removing step removes pixel data indicating an output value caused by a defect of the white calibration plate from each measurement result measured in the first measurement step, It is preferable that the output value of the pixel is the output value of the pixel.

  According to this configuration, the pixel data indicating the output value due to the defect of the white calibration plate is removed from each measurement result measured in the first measurement step, and the output values of other neighboring pixels are Since the output value is used, defects on the white calibration plate can be removed, and an accurate average value for each pixel can be calculated.

  In the white calibration method, it is preferable that the all-pixel average calculating step calculates an average value of the entire pixels from the measurement result measured in the second measuring step.

  According to this configuration, since the average value of the entire pixel is calculated from the measurement result measured in the second measurement step, the calibration value for each pixel with respect to the entire pixel and the calculated average value of the entire pixel are obtained. Based on this, a white calibration value for each pixel can be calculated.

  In the white calibration method, the average value of all pixels included in each region obtained by dividing all pixels into a plurality of regions from the measurement result measured in the second measurement step may be used as the all pixel average calculation step. Is preferably calculated.

  According to this configuration, since the average value of the pixels included in each region obtained by dividing all the pixels into a plurality of regions is calculated from the measurement result measured in the second measurement step, illumination that illuminates the white calibration plate Even if the brightness or unevenness of the white light changes, it is possible to obtain a white calibration value from which the change has been removed.

  Further, in the white calibration method, the calibration value calculating step divides the average value for each pixel calculated in the pixel average calculation step by the average value of all the pixels to thereby calculate each pixel for the entire pixel. It is preferable to calculate a calibration value.

  According to this configuration, the calibration value for each pixel with respect to the entire pixel is calculated by dividing the average value for each pixel calculated in the pixel average calculation step by the average value of all pixels. Therefore, since the average value for each pixel is divided by the average value for all pixels, a calibration value indicating the degree of variation for each pixel with respect to the entire pixel can be calculated.

  In the white calibration method, the white calibration value calculating step is a product of the calibration value stored in the storing step and the average value of all pixels calculated in the all pixel average calculating step, It is preferable to calculate a white calibration value for each pixel by dividing the price value of the white calibration plate measured by the instrument.

  According to this configuration, the product of the calibration value stored in the storage step and the average value of all the pixels calculated in the all-pixel average calculation step is used to obtain the pricing value of the white calibration plate measured in advance by the reference device. The white calibration value for each pixel is calculated by dividing. Therefore, the white calibration value for each pixel is divided by the product of the calibration value for each pixel with respect to the entire pixel and the average value of all pixels, so that the pricing value of the white calibration plate measured in advance by the reference device is divided. Can be calculated.

  A two-dimensional photometric apparatus according to still another configuration of the present invention includes a measuring unit that measures a white calibration plate serving as a calibration reference by a two-dimensional area sensor, and at least two different positions of the white calibration plate by the measuring unit. A removal means for removing pixel data indicating an output value due to a defect in the white calibration plate from the measurement result, and a measurement result in which pixel data indicating an output value due to a defect in the white calibration plate is removed by the removal means. A pixel average calculating means for calculating an average value for each pixel from the above, and a calibration value calculation for calculating a calibration value for each pixel for the entire pixel based on the average value for each pixel calculated by the pixel average calculating means Means, a storage unit for storing the calibration value calculated by the calibration value calculation means, and the white calibration plate is measured only once by the two-dimensional area sensor by the measurement means. Based on the average value of all the pixels calculated from the result, the calibration value stored by the storage unit, and the average value of all the pixels calculated by the all-pixel average calculation unit, White calibration value calculating means for calculating a white calibration value for each pixel.

  According to this configuration, the white calibration plate serving as a calibration reference is measured by the measurement unit using the two-dimensional area sensor, and the white unit is obtained from the result of measuring the different positions of the white calibration plate at least twice by the measurement unit using the removal unit. Pixel data indicating an output value resulting from a defect in the calibration plate is removed. Then, an average value for each pixel is calculated from the measurement result in which the pixel data indicating the output value due to the defect of the white calibration plate is removed by the pixel average calculating unit, and the pixel average is calculated by the calibration value calculating unit. Based on the average value for each pixel calculated by the calculation means, the calibration value for each pixel for the entire pixel is calculated, and the calibration value calculated by the calibration value calculation means is stored by the storage unit. Further, the average value of all the pixels is calculated from the result of measuring the white calibration plate by the two-dimensional area sensor only once by the measuring means by the all-pixel average calculating means, and stored in the storage unit by the white calibration value calculating means. A white calibration value for each pixel is calculated based on the calibration value and the average value of all the pixels calculated by the all-pixel average calculating means.

  Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. Can be obtained, and errors due to various unevenness between pixels of the same photometer can be suppressed.

  In the above two-dimensional photometry device, the sample measurement means for measuring the sample to be measured by the two-dimensional area sensor, and the measurement result measured by the sample measurement means are calculated by the white calibration value calculation means. It is preferable to further include correction means for correcting with the white calibration value for each pixel.

  According to this configuration, the sample to be measured is measured by the two-dimensional area sensor, and the measured measurement result is corrected by the calculated white calibration value for each pixel. Therefore, even if white calibration is performed using a white calibration plate with defects with non-uniform reflectance, the white calibration value is the same as when white calibration plates with uniform reflectance are removed and the white calibration plate with uniform reflectance is removed. By correcting the measurement result obtained by measuring the sample with the white calibration value, accurate color information can be obtained.

  According to the first aspect of the present invention, even when white calibration is performed using a white calibration plate having defects with nonuniform reflectance, the white calibration plate having uniform reflectance is removed by removing defects from the white calibration plate. The same white calibration value as in the case of using can be obtained, and errors caused by various unevenness between pixels of the same photometer can be suppressed.

  According to the second aspect of the present invention, it is possible to remove the defect of the white calibration plate and calculate an accurate average value for each pixel.

  According to the third aspect of the invention, the white calibration value for each pixel is calculated by dividing the pricing value of the white calibration plate measured in advance by the reference device by the average value for each pixel. Therefore, the white calibration value for each pixel can be calculated.

  According to the fourth aspect of the present invention, even when white calibration is performed using a white calibration plate having a defect with nonuniform reflectance, the white calibration plate having a uniform reflectance is removed by removing the defect on the white calibration plate. The same white calibration value as in the case of using can be obtained, and errors caused by various unevenness between pixels of the same photometer can be suppressed.

  According to the fifth aspect of the present invention, even when white calibration is performed using a white calibration plate having a defect with nonuniform reflectance, the white calibration plate having a uniform reflectance is removed by removing the defect of the white calibration plate. The same white calibration value as in the case of using can be obtained, and accurate color information can be obtained by correcting the measurement result obtained by measuring the sample with this white calibration value.

  According to the sixth aspect of the present invention, even if white calibration is performed using a white calibration plate having defects with nonuniform reflectance, the white calibration plate having uniform reflectance is removed by removing the defects on the white calibration plate. The same white calibration value as in the case of using can be obtained, and errors caused by various unevenness between pixels of the same photometer can be suppressed.

  According to the seventh aspect of the present invention, it is possible to remove the defect of the white calibration plate and calculate an accurate average value for each pixel.

  According to the eighth aspect of the invention, the white calibration value for each pixel can be calculated based on the calibration value for each pixel with respect to the entire pixel and the calculated average value for the entire pixel.

  According to the ninth aspect of the present invention, even if the luminance or unevenness of the illumination that illuminates the white calibration plate changes, it is possible to obtain a white calibration value from which the change is removed.

  According to the tenth aspect of the invention, the average value for each pixel is divided by the average value for all pixels, so that a calibration value indicating the degree of variation for each pixel with respect to the entire pixel can be calculated.

  According to the eleventh aspect of the present invention, the price of the white calibration plate measured in advance by the reference device by the product of the calibration value indicating the degree of variation for each pixel with respect to the entire pixel and the average value of all the pixels. Therefore, the white calibration value for each pixel can be calculated.

  According to the invention described in claim 12, even when white calibration is performed using a white calibration plate having defects with nonuniform reflectance, the white calibration plate having uniform reflectance is removed by removing the defects of the white calibration plate. The same white calibration value as in the case of using can be obtained, and errors caused by various unevenness between pixels of the same photometer can be suppressed.

  According to the thirteenth aspect of the present invention, even when white calibration is performed using a white calibration plate having a defect with nonuniform reflectance, the white calibration plate having a uniform reflectance is removed by removing the defect of the white calibration plate. The same white calibration value as in the case of using can be obtained, and accurate color information can be obtained by correcting the measurement result obtained by measuring the sample with this white calibration value.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, about the same structure in each figure, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a two-dimensional spectroscopic measurement apparatus (two-dimensional photometry apparatus) according to the first embodiment. A two-dimensional spectroscopic measurement apparatus 10 shown in FIG. 1 includes a light source 1, a collimator lens 2, a light receiving optical system 3, a two-dimensional area sensor 4, a turntable 5, and a motor 6.

  The light source 1 is composed of, for example, a halogen lamp or LED (Light Emitting Diode) that can be continuously lit, and illuminates the sample S or white calibration plate H that is a measurement target. The collimator lens 2 makes light from the light source 1 substantially parallel light in order to efficiently illuminate the sample S or the white calibration plate H.

  The light receiving optical system 3 is constituted by, for example, a camera lens or the like, and guides the reflected light reflected by the sample S or the white calibration plate H to the two-dimensional area sensor 4. The light receiving optical system 3 may be a finite imaging optical system that forms an image of reflected light on the two-dimensional area sensor 4 at a finite distance, an optical system that diffuses received light, or the like.

  The two-dimensional area sensor 4 is a sensor in which a plurality of photoelectric conversion elements are two-dimensionally arranged to form a light receiving surface. For example, the two-dimensional area sensor 4 is composed of a CCD (Charge Coupled Device) or the like, and has a light intensity of received wavelength components. Each photoelectric conversion element outputs a corresponding electrical signal by photoelectric conversion. As the two-dimensional area sensor 4, a CMOS or the like may be used.

  A turntable 5 is disposed between the light receiving optical system 3 and the two-dimensional area sensor 4. The turntable 5 includes a number of optical filters 7 (for example, 16) to be dispersed on a concentric circle with the rotation axis 5a of the motor 6 as the center. The optical filter 7 is composed of, for example, a colored glass filter and has a spectral transmittance characteristic that transmits light of a specific wavelength. For example, an interference filter may be used as the optical filter 7.

  The motor 6 is composed of, for example, a stepping motor that can be stopped temporarily, and rotates the rotating disk 5. As the motor 6, a continuous rotation type motor such as a DC motor may be used as long as the positions of all the optical filters 7 can be detected.

  Here, the operation at the time of white calibration of the two-dimensional spectrometer 10 will be described. First, the light source 1 emits light toward the white calibration plate H. The light from the light source 1 is collimated by the collimator lens 2 and illuminates the white calibration plate H. The reflected light reflected by the white calibration plate H enters the light receiving optical system 3. The light receiving optical system 3 guides the incident reflected light to the light receiving surface of the two-dimensional area sensor 4 and forms an image on the two-dimensional area of the white calibration plate H. The reflected light emitted from the light receiving optical system 3 is split by the optical filter 7 provided on the rotating disk 5, and only light having a predetermined wavelength enters the two-dimensional area sensor 4. The two-dimensional area sensor 4 receives the reflected light reflected by the white calibration plate H, and acquires the image of the two-dimensional area of the white calibration plate H by photoelectrically converting the received reflected light.

  FIG. 2 is a diagram showing measurement areas that can be measured by the two-dimensional area sensor 4 in the white calibration plate H. The two-dimensional area sensor 4 has a measurement area in a smaller range than the white calibration plate H as shown in FIG.

  Here, the output from the two-dimensional area sensor 4 when the white calibration plate H having no defect is measured will be described. The defect in the white calibration plate H is a state in which the reflectance such as black spots, pinholes, scratches, and unevenness on the white calibration plate H is not uniform. FIG. 3 is a diagram showing the output of the pixels on the line AA shown in FIG. 2 when the white calibration plate H is imaged by the two-dimensional area sensor 4.

  As shown in FIG. 3, the output of the pixel between A and A is not constant but irregular due to the influence of illumination, CCD sensitivity, lens, and the like. Furthermore, the figure which decomposed | disassembled the output of the pixel between this AA into each nonuniformity element is shown in FIGS.

  FIG. 4 is a diagram illustrating the influence on the pixel output between A and A due to uneven illumination. When the white calibration plate H is illuminated by the light source 1, the central portion of the measurement area has a large amount of light and the peripheral portion has a small amount of light. Therefore, the output from each pixel between A and A is shown in FIG. As shown, the central portion is large and the peripheral portion is small.

  FIG. 5 is a diagram illustrating the influence on the output of the pixel between A and A due to the unevenness of the CCD sensitivity. The output from each pixel between A and A is not constant as shown in FIG. 5 due to the influence of the CCD sensitivity of the two-dimensional area sensor 4.

  FIG. 6 is a diagram illustrating the influence on the pixel output between A and A due to lens unevenness (peripheral light amount decrease). The output from each pixel between A and A is affected by the light receiving optical system 3, and as shown in FIG. 6, the central portion is large and the peripheral portion is small.

  FIG. 7 is a diagram illustrating the influence on the pixel output between A and A due to the unevenness of the white calibration plate. Since there is no defect in the white calibration plate H, the output from each pixel between A and A is constant as shown in FIG.

In the conventional white calibration process, the color value determined from the output shown in FIG. 2 (tristimulus _{values) t X 0n, t Y 0n} , and _t Z _0n, the pricing value by the reference instrument white calibration plate H X ₀ , Y ₀ , Z ₀ , white calibration coefficients (white calibration values) K _Xn , K _Yn , K _Zn for each pixel can be obtained based on the following equations (1) to (3).
K _Xn = X ₀ / _t X _0n (1)
K _Yn = Y ₀ / _t Y _0n (2)
K _Zn = Z ₀ / _t Z _0n (3)

Then, by multiplying the white calibration coefficients K _Xn , K _Yn , and K _Zn for each pixel by the output value when the sample S is measured, the color values from which the influence of unevenness shown in FIGS. 4 to 6 is removed are obtained. be able to.

  In this way, the white calibration coefficient is obtained by the white calibration process, and the output becomes constant by multiplying the obtained white calibration coefficient by the output value when the sample S is measured, and accurate color information of the sample S, for example, The absolute value and distribution of the color can be obtained.

  On the other hand, when the white calibration plate H has a defect, the output of the pixel between A and A is as shown in FIG. That is, as shown in FIG. 8, the output of the pixel between A and A is not constant but irregular due to the influence of illumination, CCD sensitivity, lens, etc. Further, the influence of the defect of the white calibration plate H As a result, the output of the pixel corresponding to the defective portion of the white calibration plate H protrudes.

  FIG. 9 is a diagram illustrating the influence on the output of the pixel between A and A due to the unevenness of the white calibration plate. Each pixel between A and A shown in FIG. 9 is compared to FIG. 7 showing the influence of the unevenness of the white calibration plate H on the output of the pixel between A and A when the white calibration plate H without a defect is imaged. Since the white calibration plate H has a defect, the output from is not constant, and the output of the pixel corresponding to the defective portion of the white calibration plate H protrudes.

  FIG. 10 is a diagram illustrating an output of a pixel between A and A when a sample is measured using a defective white calibration plate. When the white calibration coefficient is obtained with the output shown in FIG. 8, since the defect of the white calibration coefficient affects the white calibration coefficient, when the sample S is measured using such a white calibration coefficient, as shown in FIG. The output is not constant and accurate color information cannot be obtained.

  Therefore, in this embodiment, even if white calibration is performed using a white calibration plate H having a defect with nonuniform reflectance, the white calibration plate H having a uniform reflectance is removed by removing the defect of the white calibration plate H. The purpose is to obtain the same white calibration value as used.

  FIG. 11 is a block diagram showing an internal configuration of the two-dimensional spectrometer according to the first embodiment. A two-dimensional spectroscopic measurement apparatus 10 shown in FIG. 11 includes a two-dimensional area sensor 4, a control unit 21, a storage unit 22, and an output unit 23. Note that here, the white calibration plate measurement unit 211, the average value calculation unit 212, the convergence determination unit 213, the all-pixel average calculation unit 214, the manufacturer calibration value calculation unit 215, the user calibration value calculation unit 216, and the white calibration coefficient calculation unit 217. The part constituted by the manufacturer calibration value storage unit 221, the reference calibration value storage unit 222, and the white calibration coefficient storage unit 223 is referred to as a white calibration device 20.

  The control unit 21 includes a white calibration plate measurement unit 211, an average value calculation unit 212, a convergence determination unit 213, an all-pixel average calculation unit 214, a manufacturer calibration value calculation unit 215, a user calibration value calculation unit 216, and a white calibration coefficient calculation unit 217. A sample measuring unit 218 and a measurement value correcting unit 219 are provided.

  The white calibration plate measurement unit 211 measures spectral data output from the two-dimensional area sensor 4 that has received the reflected light from the white calibration plate H, and uses the spectral data to measure the spectral reflection characteristic R ( λ) is obtained, and tristimulus values X, Y, Z for each pixel are calculated based on the obtained spectral reflection characteristic R (λ). The white calibration plate measurement unit 211 measures at least twice at different positions of the white calibration plate H that is a reference for calibration.

The average value calculation unit 212 removes the defect for each pixel from each measurement result measured by the white calibration plate measurement unit 211, and calculates the average value for each pixel from the measurement result from which the defect has been removed. That is, when a value obtained by averaging the measurement values for each pixel is obtained, the value converges to a certain value as the number of measurements increases. Therefore, the average value calculation unit 212 averages a plurality of times of measurement results measured by the white calibration plate measurement unit 211 to thereby obtain average values (convergence values) _CM X _n , _CM Y _n , _CM Z _{n for} each pixel. Ask for. Note that n is a pixel number associated with each pixel, and n = 1, 2,...

  In addition, the average value calculation unit 212 outputs an abnormal output because the measurement result (tristimulus values X, Y, Z) of each pixel measured by the white calibration plate measurement unit 211 is affected by the defect of the white calibration plate H. In the case shown, the measurement result of the pixel is removed, and the measurement value of the pixel in the vicinity of the pixel is adopted. For example, when the measurement result for each pixel measured by the white calibration plate measurement unit 211 is outside a predetermined range set in advance, the average value calculation unit 212 discards the measurement result for the pixel. The predetermined range is, for example, a range divided into white in the chromaticity coordinates of the XYZ color system.

  The convergence determination unit 213 determines whether the average value calculated by the average value calculation unit 212 has converged. That is, the convergence determination unit 213 compares the average value calculated this time by the average value calculation unit 212 with the average value calculated once before, and if the difference is within a predetermined range, for example, 1%. Judge that it has converged.

The all-pixel average calculation unit 214 is based on the average values _CM X _n , _CM Y _n , _CM Z _n (n = 1, 2, 3,..., N) calculated by the average value calculation unit 212. The average values _AMX , _AMY , _{AMZ of the} whole are calculated. The average value _AM X of the entire screen, _AM Y, _AM Z is calculated by (4) to (6) below.

The manufacturer calibration value calculation unit 215 includes the average values _CM X _n , _CM Y _n , and _CM Z _n calculated by the average value calculation unit 212, and the average value _AMX , _{Based on AM} Y and _AM Z, manufacturer calibration values _M X _n , _M Y _n , _M Z _n (n = 1, 2, 3,..., N indicating the degree of variation between pixel outputs for each pixel. ) Is calculated. The manufacturer calibration values _M X _n , _M Y _n , and _M Z _n are calculated by the following equations (7) to (9).
_M X _n = _CM X _n / _AM X (7)
_M Y _n = _CM Y _n / _AM Y (8)
_{M Z n = CM Z n /} AM Z ···· (9)

The manufacturer calibration value calculation unit 215 stores the calculated manufacturer calibration values _M X _n , _M Y _n , and _M Z _n in the manufacturer calibration value storage unit 221.

The user calibration value calculation unit 216 calculates user calibration values _U X, _U Y, and _U Z that are average values of the entire screen from the measurement result measured by the white calibration plate measurement unit 211.

White calibration coefficient calculation unit 217, the manufacturer calibration value _M X _n stored in the manufacturer calibration value storage unit _{221, M Y n, M Z} n and the calculated entire screen average value by a user calibration value calculation unit 216 Is calculated by dividing the reference calibration values X ₀ , Y ₀ , and Z ₀ stored in advance in the reference calibration value storage unit 222 by the product of the user calibration values _U X, _U Y, and _U Z. To calculate white calibration coefficients K _Xn , K _Yn , and K _Zn (n = 1, 2, 3,..., N) for each pixel. The white calibration coefficients K _Xn , K _Yn , and K _Zn are calculated by the following equations (10) to (12).
K _Xn = X ₀ / ( _M X _n · _U X) (10)
K _Yn = Y ₀ / ( _M Y _n · _U Y) (11)
K _Zn = Z ₀ / ( _M Z _n · _U Z) (12)

The white calibration coefficient calculation unit 217 stores the calculated white calibration coefficient values K _Xn , K _Yn , and K _Zn in the white calibration coefficient storage unit 223.

The sample measurement unit 218 measures the spectral data output from the two-dimensional area sensor 4 that has received the reflected light from the sample S that is the measurement target, and uses the spectral data to measure the spectral reflection characteristic R (λ) of the sample S. And tristimulus values X _n ′, Y _n ′, Z _n ′ (n = 1, 2, 3,..., N) for each pixel are calculated based on the obtained spectral reflection characteristic R (λ). To do.

The measurement value correction unit 219 includes the tristimulus values X _n ′, Y _n ′, and Z _n ′ for each pixel calculated by the sample measurement unit 218, and each pixel stored in the white calibration coefficient storage unit 223. The measured values are corrected by multiplying the white calibration coefficients K _Xn , K _Yn , K _Zn and the tristimulus values X _n , Y _n , Z _{n for} each pixel (n = 1, 2, 3,... , N) is calculated as a correction value. The tristimulus values X _n , Y _n , and Z _{n for} each pixel are calculated by the following equations (13) to (15).
X _n = K _Xn × X _n '(13)
Y _n = K _Yn × Y _n ′ (14)
Z _n = K _Zn × Z _n ′ (15)

  The storage unit 22 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), and includes a manufacturer calibration value storage unit 221, a reference calibration value storage unit 222, and a white calibration coefficient storage unit 223.

The manufacturer calibration value storage unit 221 stores the manufacturer calibration values _M X _n , _M Y _n , and _M Z _n calculated by the manufacturer calibration value calculation unit 215. The reference calibration value storage unit 222 stores, as reference calibration values X ₀ , Y ₀ , Z ₀ , values obtained by pricing the white calibration plate H measured in advance by the reference device. The white calibration coefficient storage unit 223 stores the white calibration coefficients K _Xn , K _Yn , and K _Zn calculated by the white calibration coefficient calculation unit 217.

The output unit 23 is, for example, a liquid crystal monitor or the like, and outputs the tristimulus values X _n of each pixel calculated by the measurement value correcting unit 219, Y _n, a Z _n as an output value.

  Next, the white calibration process in the first embodiment will be described. FIG. 12 is a flowchart showing white calibration processing performed on the maker side by the two-dimensional spectrometer 10 shown in FIG. FIG. 12 shows white calibration processing performed on the manufacturer side before shipment.

  In step S1, the white calibration plate measuring unit 211 measures different positions of the white calibration plate H serving as a calibration reference at least twice or more. That is, by measuring different positions of the white calibration plate H at least twice, the average value of the output values of the same pixel at different measurement times can be converged, and defects due to the white calibration plate H for each pixel are eliminated. Can be removed.

  In step S2, the average value calculation unit 212 removes the defect for each pixel from each measurement result measured by the white calibration plate measurement unit 211, and calculates the average value for each pixel from the measurement result from which the defect is removed. calculate.

  In step S <b> 3, the convergence determination unit 213 determines whether the average value calculated by the average value calculation unit 212 has converged.

In step S4, all the pixel average calculating unit 214, an average value average _CM X _n calculated by the calculating unit 212, _CM Y _{n, CM} Z based on _n, the entire screen average value _AM X, _AM Y, _AM Z is calculated.

In step S 5, the manufacturer calibration value calculation unit 215 calculates the average values _CM X _n , _CM Y _n , and _CM Z _n calculated by the average value calculation unit 212 and the average of the entire screen calculated by the all pixel average calculation unit 214. value _AM X, _AM Y, based on the _AM Z, manufacturer calibration value indicating the variation degree between pixel output for each pixel _M X _{n, M} Y _n, to calculate the _M Z _n.

In step S _< b _> 6, the manufacturer calibration value calculation unit 215 stores the calculated manufacturer calibration values _{M Xn} , _M Y _n , and _M Z _n for each pixel in the manufacturer calibration value storage unit 221.

  Next, the white calibration process performed on the user side will be described. FIG. 13 is a flowchart showing white calibration processing performed on the user side by the two-dimensional spectrometer 10 shown in FIG. FIG. 13 shows white calibration processing performed on the user side when measuring a sample.

  In step S <b> 11, the white calibration plate measurement unit 211 measures spectral data output from the two-dimensional area sensor 4 that has received the reflected light from the white calibration plate H, and uses the spectral data to measure the spectrum of the white calibration plate H. The reflection characteristic R (λ) is obtained, and tristimulus values X, Y, and Z for each pixel are calculated based on the obtained spectral reflection characteristic R (λ).

In step S12, the user calibration value calculation unit 216 calculates user calibration values _U X, _U Y, and _U Z that are average values of the entire screen from the measurement results measured by the white calibration plate measurement unit 211.

In step S 13, the white calibration coefficient calculation unit 217 displays the manufacturer calibration values _M X _n , _M Y _n , and _M Z _n stored in the manufacturer calibration value storage unit 221 and the screen calculated by the user calibration value calculation unit 216. A product of user calibration values _U X, _U Y, and _U Z that are average values of the whole is obtained, and the reference calibration values X ₀ , Y ₀ , Z ₀ stored in the reference calibration value storage unit 222 in advance with the obtained values. Is divided to calculate white calibration coefficients K _Xn , K _Yn , and K _Zn for each pixel.

In step S <b> 14, the white calibration coefficient calculation unit 217 stores the calculated white calibration coefficients K _Xn , K _Yn , and K _Zn in the white calibration coefficient storage unit 223.

  In step S15, the sample measurement unit 218 determines whether or not the measurement of the sample S by the user is performed. If it is determined that the sample S is measured by the user (YES in step S15), the process proceeds to step S16, and if it is determined that the sample S is not measured by the user (NO in step S15). ), Until the measurement of the sample S by the user is performed.

In step S16, the sample measuring unit 218 measures the sample S. Specifically, the sample measurement unit 218 measures spectral data output from the two-dimensional area sensor 4 that has received the reflected light from the sample S, and uses the spectral data to measure the spectral reflection characteristic R (λ) of the sample S. And tristimulus values X _n ′, Y _n ′, and Z _n ′ for each pixel are calculated based on the obtained spectral reflection characteristic R (λ).

In step S <b> 17, the measurement value correction unit 219 multiplies the measurement value for each pixel of the sample S measured by the sample measurement unit 218 by the white calibration coefficient stored in the white calibration coefficient storage unit 223. , Correct the measured value. Specifically, the measurement value correction unit 219 reads the white calibration coefficients K _Xn , K _Yn , and K _Zn for each pixel from the white calibration coefficient storage unit 223, and reads the white calibration coefficients K _Xn , The measured values are corrected by multiplying K _Yn , K _Zn by the tristimulus values X _n ′, Y _n ′, Z _n ′ for each pixel calculated by the sample measuring unit 218, and three for each pixel. Stimulus values X _n , Y _n and Z _n are calculated.

In step S18, the output unit 23, the tristimulus values X _n of each pixel calculated by the measurement value correcting unit 219, Y _n, and outputs a Z _n.

The output unit 23 in the present embodiment, the tristimulus values X _n for each pixel, Y _n, a Z _n, for example, although output by displaying on the liquid crystal monitor or the like, the present invention is particularly to For example, it may be output by sound, may be output by printing on paper, or may be output by recording on a computer-readable recording medium such as a CD-R or DVD-R. Good.

  In addition, the convergence determination unit 213 in the present embodiment compares the average value calculated this time by the average value calculation unit 212 with the average value calculated one time before, and if the difference is within a predetermined range. Although the present invention is determined to have converged, the present invention is not particularly limited to this. The number of measurements to converge in advance is experimentally obtained, the obtained number of measurements is set in advance, and the set number of measurements is reached. In this case, it may be determined that it has converged.

  In this manner, the white calibration plate measuring unit 211 measures at least two different positions of the white calibration plate H serving as a calibration reference by the two-dimensional area sensor 4, and the average value calculating unit 212 measures the white calibration plate. Pixel data indicating an output value due to a defect in the white calibration plate H is removed from each measurement result measured by the unit 211, and an average value for each pixel is calculated from the removed measurement result to calculate a manufacturer calibration value. Based on the average value for each pixel calculated by the average value calculation unit 212, the unit 215 calculates a manufacturer calibration value indicating the degree of variation for each pixel with respect to the entire pixel, and the calculated manufacturer calibration value is the manufacturer calibration value. It is stored in the value storage unit 221. Then, the white calibration plate H is measured only once by the two-dimensional area sensor 4 by the white calibration plate measurement unit 211, and all the pixels are obtained from the measurement result measured by the white calibration plate measurement unit 211 by the user calibration value calculation unit 216. Is calculated as a user calibration value, and the white calibration coefficient calculation unit 217 converts the manufacturer calibration value stored in the manufacturer calibration value storage unit 221 and the user calibration value calculated by the user calibration value calculation unit 216. Based on this, a white calibration coefficient for each pixel is calculated.

  Therefore, even when white calibration is performed using a white calibration plate H having a defect with nonuniform reflectance, the defect is removed from the white calibration plate H and the same as when using the white calibration plate H with uniform reflectance. A white calibration coefficient can be obtained, and errors due to various unevenness between pixels of the same photometer can be suppressed.

  Further, the sample measurement unit 218 measures the sample S to be measured by the two-dimensional area sensor 4, and the measurement value correction unit 219 measures the measurement result measured by the sample measurement unit 218 by the white calibration coefficient output unit 217. Since it is corrected by the calculated white calibration coefficient for each pixel, accurate color information can be obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, after measuring the white calibration plate H in step S11 shown in FIG. 13, the average value of the entire screen is calculated in step S12. In the second embodiment, the entire screen is calculated. It divides | segments into a some area | region and calculates the average value in the divided | segmented area | region.

  FIG. 14 is a block diagram showing an internal configuration of the two-dimensional spectrometer in the second embodiment. 14 includes a two-dimensional area sensor 4, a control unit 21, a storage unit 22, and an output unit 23. In the following description, the same components as those of the two-dimensional spectrometer 10 in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Also, here, the white calibration plate measurement unit 211, the average value calculation unit 212, the convergence determination unit 213, the all pixel average calculation unit 214, the manufacturer calibration value calculation unit 215, the divided region pixel average calculation unit 220, and the white calibration coefficient calculation unit The part constituted by 217 ′, the manufacturer calibration value storage unit 221, the reference calibration value storage unit 222, and the white calibration coefficient storage unit 223 is referred to as a white calibration device 20 ′.

  The control unit 21 includes a white calibration plate measurement unit 211, an average value calculation unit 212, a convergence determination unit 213, an all-pixel average calculation unit 214, a manufacturer calibration value calculation unit 215, a white calibration coefficient calculation unit 217 ′, a sample measurement unit 218, A measurement value correction unit 219 and a divided region pixel average calculation unit 220 are provided.

The divided region pixel average calculation unit 220 divides an image obtained from the measurement result measured by the white calibration plate measurement unit 211 into a plurality of θ regions, and averages _U Xθ, _{U for} each divided region. Yθ, _U Zθ (θ = 1, 2, 3,..., Θ) are calculated. The divided area is an area obtained by dividing an image captured by the two-dimensional area sensor 4 into a rectangular shape, and the number of areas to be divided is set in advance according to the required accuracy. In addition, the divided region θ and the pixel number n of the pixel included in the divided region θ are associated in advance.

The white calibration coefficient calculation unit 217 ′ includes manufacturer calibration values _M X _n , _M Y _n , _M Z _n (n = 1, 2, 3,..., N) stored in the manufacturer calibration value storage unit 221. The product of the average values _U Xθ, _U Yθ, _U Zθ for each divided region calculated by the divided region pixel average calculation unit 220 is obtained, and the reference stored in the reference calibration value storage unit 222 in advance with the obtained value. By dividing the calibration values X ₀ , Y ₀ , Z ₀ , white calibration coefficients K _Xn , K _Yn , K _Zn (n = 1, 2, 3,..., N) for each pixel are calculated. The white calibration coefficients K _Xn , K _Yn , and K _Zn are calculated by the following equations (16) to (18). Since the divided region θ and the pixel number n of the pixel included in the divided region θ are associated with each other in advance, the white calibration coefficient calculation unit 217 ′ uses the manufacturer calibration value _M X _n of the pixel number n, The product of the divided value θ including the pixel number n and the average value _U Xθ can be obtained.
K _Xn = X ₀ / ( _M X _n · _U Xθ) (16)
K _Yn = Y ₀ / ( _M Y _n · _U Yθ) (17)
K _Zn = Z ₀ / ( _M Z _n · _U Zθ) (18)

The white calibration coefficient calculation unit 217 ′ stores the calculated white calibration coefficient values K _Xn , K _Yn , and K _Zn in the white calibration coefficient storage unit 223.

  Next, the white calibration process in the second embodiment will be described. FIG. 15 is a flowchart showing white calibration processing performed on the user side by the two-dimensional spectrometer 10 'shown in FIG. FIG. 15 shows a white calibration process performed on the user side during measurement of the sample, and the white calibration process performed on the manufacturer side before shipment in the second embodiment is the same as the process shown in FIG. Description is omitted.

  The processing in step S21 is the same as the processing in step S11 in FIG.

In step S22, the divided region pixel average calculation unit 220 divides an image obtained from the measurement result measured by the white calibration plate measurement unit 211 into a plurality of θ regions, and is included for each divided region. Average values _U Xθ, _U Yθ, and _U Zθ of the pixels are calculated.

In step S23, the white calibration coefficient calculation unit 217 ′ is calculated by the manufacturer calibration values _M X _n , _M Y _n , and _M Z _n stored in the manufacturer calibration value storage unit 221 and the divided region pixel average calculation unit 220. The product of the average values _U Xθ, _U Yθ, _U Zθ for each divided region is obtained, and the reference calibration values X ₀ , Y ₀ , Z ₀ stored in advance in the reference calibration value storage unit 222 are obtained with the obtained values. By dividing, white calibration coefficients K _Xn , K _Yn , and K _Zn for each pixel are calculated.

  The processing from step S24 to step S28 is the same as the processing from step S14 to step S18 in FIG.

  Thus, since the average value of the pixels included in each region obtained by dividing all the pixels into a plurality of regions from the measurement result measured by the white calibration plate measuring unit 211 is calculated as the user calibration value, the white calibration plate H Even if the brightness or unevenness of the illumination for illuminating changes, it is possible to obtain a white calibration value with the change removed.

  Next, modified examples of the first and second embodiments will be described. In each of the above embodiments, the process of measuring the white calibration plate shown in FIG. 12 twice or more is performed by the manufacturer. On the other hand, in the modified example, the white calibration plate shown in FIG. 12 is measured on the user side. Therefore, in this case, “manufacturer calibration value” is read as “first calibration value”, and “user calibration value” is read as “second calibration value”. The first calibration value is obtained by first measuring on the manufacturer side, and further includes both cases where the measurement is performed and corrected on the user side, and cases where the first calibration value is obtained only on the user side.

  In other words, the white calibration process shown in FIG. 12 can be performed prior to the first use of the apparatus on the user side instead of the manufacturer side (or in addition to the manufacturer side). By performing this process on the user side periodically after starting to use the apparatus or after using it for a long period of time, it is possible to remove the change in the defect state due to the aging and contamination of the white calibration plate.

It is a figure which shows the structure of the two-dimensional spectrometry apparatus in 1st Embodiment. It is a figure which shows the measurement area which a two-dimensional area sensor can measure in a white calibration board. It is a figure which shows the output of the pixel on the AA line shown in FIG. 2 when a white calibration board is imaged with a two-dimensional area sensor. It is a figure shown about the influence on the output of the pixel between AA by the nonuniformity of illumination. It is a figure which shows about the influence on the output of the pixel between AA by the nonuniformity of CCD sensitivity. It is a figure shown about the influence on the output of the pixel between AA by the nonuniformity of a lens. It is a figure which shows about the influence on the output of the pixel between AA by the nonuniformity of a white calibration board. It is a figure which shows the output of the pixel on the AA line shown in FIG. 2 when a white calibration board is imaged with a two-dimensional area sensor in case a white calibration board has a defect. It is a figure which shows about the influence on the output of the pixel between AA by the nonuniformity of a white calibration board in case a white calibration board has a defect. It is a figure which shows the output of the pixel between AA at the time of measuring a sample using a white calibration board with a defect. It is a block diagram which shows the internal structure of the two-dimensional spectrometry apparatus in 1st Embodiment. It is a flowchart which shows the white calibration process performed by the maker side with the two-dimensional spectrometry apparatus shown in FIG. It is a flowchart which shows the white calibration process performed by the user side by the two-dimensional spectrometry apparatus shown in FIG. It is a block diagram which shows the internal structure of the two-dimensional spectrometry apparatus in 2nd Embodiment. It is a flowchart which shows the white calibration process performed by the user side by the two-dimensional spectrometry apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Collimator lens 3 Light reception optical system 4 Two-dimensional area sensor 5 Turntable 6 Motor 7 Optical filter 10 Two-dimensional spectroscopic measurement device 20 White calibration device 21 Control unit 22 Control unit 23 Output unit 211 White calibration plate measurement unit 212 Average value Calculation unit 213 Convergence determination unit 214 All pixel average calculation unit 215 Manufacturer calibration value calculation unit 216 User calibration value calculation unit 217 White calibration coefficient calculation unit 218 Sample measurement unit 219 Measurement value correction unit 221 Manufacturer calibration value storage unit 222 Reference calibration value storage Part 223 white calibration coefficient storage part

Claims (13)

A measurement step of measuring different positions of the white calibration plate serving as a calibration reference at least twice by a two-dimensional area sensor;
A removal step of removing pixel data indicating an output value caused by a defect of the white calibration plate from each measurement result measured in the measurement step;
A pixel average calculation step for calculating an average value for each pixel from the measurement result in which the pixel data indicating the output value due to the defect of the white calibration plate is removed in the removal step;
And a white calibration value calculating step of calculating a white calibration value for each pixel with respect to the whole pixel based on the average value for each pixel calculated in the pixel average calculating step.   The removal step removes pixel data indicating an output value due to a defect of the white calibration plate from each measurement result measured in the measurement step, and outputs an output value of another neighboring pixel as an output value of the pixel. The white calibration method according to claim 1, wherein:   The white calibration value calculating step divides the price value of the white calibration plate measured in advance by the reference device by the average value for each pixel calculated in the pixel average calculating step, thereby white calibration for each pixel. The white calibration method according to claim 1, wherein a value is calculated. A measuring means for measuring a white calibration plate as a calibration reference with a two-dimensional area sensor;
Removing means for removing pixel data indicating an output value caused by a defect in the white calibration plate from a result of measuring at least two different positions of the white calibration plate by the measurement unit;
Pixel average calculating means for calculating an average value for each pixel from a measurement result in which pixel data indicating an output value due to a defect of the white calibration plate is removed by the removing means;
A two-dimensional photometric apparatus comprising: a white calibration value calculating unit that calculates a white calibration value for each pixel with respect to the entire pixel based on the average value for each pixel calculated by the pixel average calculating unit. Sample measuring means for measuring a sample to be measured by a two-dimensional area sensor;
5. The two-dimensional device according to claim 4, further comprising a correcting unit that corrects the measurement result measured by the sample measuring unit with a white calibration value for each pixel calculated by the white calibration value calculating unit. Photometric device. A first measurement step of measuring different positions of a white calibration plate serving as a calibration reference at least twice by a two-dimensional area sensor;
A removal step of removing pixel data indicating an output value caused by a defect of the white calibration plate from each measurement result measured in the first measurement step;
A pixel average calculation step for calculating an average value for each pixel from the measurement result in which the pixel data indicating the output value due to the defect of the white calibration plate is removed in the removal step;
A calibration value calculating step for calculating a calibration value for each pixel with respect to the entire pixel based on the average value for each pixel calculated in the pixel average calculating step;
A storage step of storing the calibration value calculated in the calibration value calculation step;
A second measurement step of measuring the white calibration plate only once by a two-dimensional area sensor;
An all-pixel average calculating step of calculating an average value of all pixels from the measurement result measured in the second measuring step;
A white calibration value calculating step of calculating a white calibration value for each pixel based on the calibration value stored in the storing step and the average value of all pixels calculated in the all pixel average calculating step. White calibration method characterized by   The removal step removes pixel data indicating an output value caused by a defect of the white calibration plate from each measurement result measured in the first measurement step, and outputs output values of other pixels in the vicinity of the pixel. The white calibration method according to claim 6, wherein an output value is used.   7. The white calibration method according to claim 6, wherein the all-pixel average calculating step calculates an average value of all pixels from the measurement result measured in the second measuring step.   The all-pixel average calculating step calculates an average value of all pixels included in each region obtained by dividing all pixels into a plurality of regions from the measurement result measured in the second measuring step. Item 7. The white calibration method according to Item 6.   The calibration value calculation step calculates a calibration value for each pixel with respect to the entire pixel by dividing the average value for each pixel calculated in the pixel average calculation step by the average value of all pixels. The white calibration method according to claim 6.   The white calibration value calculation step is a product of the calibration value stored in the storage step and the average value of all pixels calculated in the all pixel average calculation step. The white calibration method according to claim 6, wherein the white calibration value for each pixel is calculated by dividing the priced value. A measuring means for measuring a white calibration plate as a calibration reference with a two-dimensional area sensor;
Removing means for removing pixel data indicating an output value caused by a defect in the white calibration plate from a result of measuring at least two different positions of the white calibration plate by the measurement unit;
Pixel average calculating means for calculating an average value for each pixel from a measurement result in which pixel data indicating an output value due to a defect of the white calibration plate is removed by the removing means;
Calibration value calculation means for calculating a calibration value for each pixel with respect to the entire pixel based on the average value for each pixel calculated by the pixel average calculation means;
A storage unit for storing a calibration value calculated by the calibration value calculation means;
An all-pixel average calculating means for calculating an average value of all pixels from a result of measuring the white calibration plate only once by a two-dimensional area sensor by the measuring means;
White calibration value calculating means for calculating a white calibration value for each pixel based on the calibration value stored by the storage unit and the average value of all pixels calculated by the all pixel average calculating means. A two-dimensional photometric device characterized by Sample measuring means for measuring a sample to be measured by a two-dimensional area sensor;
A two-dimensional photometric apparatus, further comprising: a correcting unit that corrects the measurement result measured by the sample measuring unit with a white calibration value for each pixel calculated by the white calibration value calculating unit.

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