JP2007329591A - Calibration method in measurement of luminance and chromaticity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire correction data required for measuring luminance/chromaticity even in a display device and a situation, where monochromatic coloring of each primary color is difficult. <P>SOLUTION: An object to be measured is allowed to emit monochrome light to each primary color. A luminance/chromaticity measuring instrument 5 and a color camera 2 capture the image of each primary color allowed to emit monochrome light. A measurement value obtained by capturing the image is stored as a reference value for calculating luminance and chromaticity. When the correction value is stored in each primary color calculated based on the stored reference value, the monochromatic color filter of each primary color and a shade are used for blocking light except desired primary color, thus emitting monochromatic light of each primary color artificially. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a calibration method for measuring the luminance and chromaticity of an object to be measured in a display inspection process such as a display panel.

  Conventionally, a luminance and chromaticity measuring apparatus using a video camera such as a monochrome CCD (Charge-Coupled Devices) camera has been used for measuring luminance and chromaticity during a display inspection process for a display device such as a flat panel display. Here, the luminance is a value representing the intensity of light, and the chromaticity is a value obtained by removing a brightness component from a certain color, which is determined from the xy chromaticity diagram.

  When this measuring apparatus is used, luminance and chromaticity are measured by using a filter called a tristimulus value filter that applies tristimulus values related to the spectral sensitivity of the human eye. Tristimulus values are based on additive color mixing, and when all colors are displayed in a mixed amount of R (Red), G (Green), and B (Blue), which are the three primary colors of virtual light, , G, and B are values that replace X, Y, and Z, respectively, so that only Y has brightness. In conventional luminance and chromaticity measurement, the tristimulus value filter composed of three pieces of X, Y, and Z is rotated, and the light beam having the unique bandwidth set by each filter is transmitted. The values were acquired and the brightness and chromaticity were calculated.

  As a result of the measurement of luminance and chromaticity, the measurement value obtained has a measurement error due to the influence of the measuring device, color characteristics, etc., and therefore it is necessary to perform a predetermined correction process. By performing some correction processing on the measurement value, the measurement value is calibrated, and a correction value that eliminates the influence of the measurement error can be obtained.

Patent Document 1 discloses a chromaticity distribution for each color in a calibration stage for obtaining a predetermined constant matrix before a measurement stage for obtaining tristimulus values by output video signal levels R, G, and B of a color video camera and a predetermined constant matrix. The above predetermined range is represented by a plurality of points, and a calibration method for obtaining a predetermined constant matrix at the time of chromatic luminance measurement based on the plurality of points and performing chromatic luminance measurement is described.
JP 2004-120393 A (FIG. 1)

  By the way, when performing luminance and chromaticity measurement using a black and white video camera so far, the three tristimulus value filters of X, Y, and Z described above are rotated, and data is individually obtained using the respective filters. There was a problem that it took time to measure. Further, since a measuring apparatus using an XYZ filter is expensive, there has been a demand for performing measurement with a cheaper apparatus using a general-purpose color camera or the like.

  There is also a method of measuring luminance and chromaticity using a color camera without using a measurement device that uses a tristimulus filter. For example, a cold cathode tube (CCFL: Cold Cathode Fluorescent Lamp) with a white light source is used as a backlight. When the display used is an object to be measured, the cold-cathode tube emits only white light. Therefore, the primary colors of R, G, and B cannot be emitted in a single color, which is necessary for measuring luminance and chromaticity. There was a problem that it was difficult to obtain correction data.

  When a rear projection television or a liquid crystal television is an object to be measured and calibration is performed in a black state where all the liquid crystal shutters are closed, each primary color is displayed in a black state where all the liquid crystal shutters are closed. Since it is impossible to emit monochromatic light, there is a problem that correction data cannot be acquired.

  The present invention has been made in view of such a situation, and an object of the present invention is to make it possible to acquire correction data necessary for measuring luminance and chromaticity even in a display device or situation where it is difficult to develop a single color of each primary color. And

  In the first invention, an object to be measured is caused to emit light in a single color for each primary color, each primary color that is emitted in a single color is imaged with a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are represented by luminance and chromaticity. Stores as a reference value for calculation, and stores a correction value for each primary color calculated based on the stored reference value, and when the object to be measured is a display using a white light source, luminance chromaticity measurement A filter for each primary color is attached to the device and the color camera to realize single color emission of a desired primary color.

  In the second invention, the object to be measured is caused to emit a single color to each primary color, each primary color emitted by the single color is imaged by a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are represented by luminance and chromaticity. In the case of storing a correction value for each primary color that is stored as a reference value for calculation and calculated based on the stored reference value, the object to be measured is a projection device including three liquid crystal panels, and the liquid crystal shutter is When acquiring correction data in a closed black state, insert a light-shielding plate in front of or behind two liquid crystal panels that transmit light of a color other than the color that you want to obtain monochromatic light out of the three liquid crystal panels. By doing so, it is possible to realize monochromatic light emission of a desired primary color.

  According to a third aspect of the present invention, an object to be measured is made to emit light in a single color for each primary color, each primary color that has been emitted in a single color is imaged with a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are used for luminance and chromaticity. In the case of storing the correction value of each primary color that is stored as a calculation reference value and calculated based on the stored reference value, the object to be measured is a liquid crystal display provided with a color filter of each primary color, and all the liquid crystal shutters are When acquiring correction data in a closed black state, a single color light emission of a desired primary color is realized by using a single color filter of each primary color instead of a color filter of each primary color.

  In this way, when a display using a light source that can emit only white monochromatic light is an object to be measured, or when it is difficult to emit monochromatic light of each primary color, such as a black state where all liquid crystals are closed, Light other than the primary colors is blocked.

  According to the present invention, it is desirable to use a color filter or a light shielding plate even in a situation where it is difficult to emit monochromatic light of each primary color, such as a display that is difficult to emit monochromatic light of each primary color or a black state where all liquid crystals are closed. By blocking light other than the primary colors, pseudo-monochromatic emission of each primary color is realized, so that correction data can be acquired.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the present embodiment, the present invention is applied to a luminance / chromaticity measuring apparatus that performs panel surface luminance and chromaticity inspection in an inspection process of a display device such as a display panel.

  First, an example of the external configuration of the luminance / chromaticity measuring apparatus of this example will be described. FIG. 1 shows an example of the configuration of a luminance / chromaticity measuring device 1, which includes a color camera 2 having a lens 3, a spectral radiance meter 5, a computer 4, a display 14, a keyboard 15, It is composed of a mouse 16. The object 20 to be measured, which is installed as a display panel on which luminance and chromaticity measurement is performed, is imaged by the color camera 2 as an imaging unit capable of color imaging by the three primary color processes of red, green, and blue. It is. The color camera 2 is connected to the computer 4 via a cable 5.

  Next, an example of the internal configuration of the luminance / chromaticity measuring apparatus 1 will be described with reference to the block diagram of FIG. The color camera 2 converts imaging light of the measurement target image formed through the lens 3 into a video signal, and outputs an R signal, a G signal, and a B signal in the video signal to the camera interface board 12 respectively. As the color camera 2, a three-plate color video camera provided with each primary color solid-state image sensor may be used, and a single-color image pixel is arranged on one solid-state image sensor. A plate-type color video camera may be used. The spectral radiance meter 5 is a device that measures luminance and chromaticity serving as a reference for R, G, and B components of an object to be measured. Since the spectral radiance meter 5 operates stand-alone, it is assumed that the measurement value obtained by the spectral radiance meter 5 is manually input from a keyboard 15 of the computer 4 described later. In this example, the spectral radiance meter 5 is used as a luminance / chromaticity measuring device, but other devices may be used as long as they can measure luminance / chromaticity.

  The computer 4 includes a CPU (Central Processing Unit) 13, an HDD (Hard Disk Drive) 10, a memory 11, a camera interface board 12, and the like. The HDD (Hard Disk Drive) 10, the memory 11, and the camera interface board 12 are connected to a system bus 17. It is connected to the CPU 13 via The CPU 13 performs control such as calibration processing for obtaining correction data and correction processing based on the correction data, and also controls each unit in the computer. The HDD 10 stores brightness / chromaticity measurement results and the like, and the memory 11 stores original image data before processing, data during processing, image data after correction processing, and the like. The camera interface board 12 outputs image data input from the color camera 2 via the cable 5 to the computer 4. In addition, a display 14, a keyboard 15, and a mouse 16 are connected to the system bus 17.

  Next, with reference to FIG. 3, the procedure of the calibration process for calculating the brightness / chromaticity of this example will be described. In order to calculate the luminance and chromaticity from the R, G, and B data obtained from the color camera 2, it is necessary to perform black level correction, shading correction, and crosstalk correction of the camera. Correction data for performing each correction process can be obtained by black level calibration, shading calibration, crosstalk calibration, and luminance / chromaticity calibration of the camera. The flowchart of FIG. 3 shows an example of each calibration procedure. First, calibration processing for black level correction is performed, and the obtained correction data is stored (step S11). Next, correction data obtained by performing calibration processing for shading correction is stored (step S12), correction data obtained by calibration processing for crosstalk correction is stored (step S13), and finally luminance and color are stored. The correction data obtained by the calibration process for correcting the degree is stored (step S14). Details of the calibration processing, correction processing, and luminance / chromaticity conversion will be described later.

  Among the calibration procedures described above, in crosstalk calibration and luminance / chromaticity calibration, it is necessary to acquire monochromatic light emission data of R, G, and B primary colors, and R, G are referred to with reference to FIGS. A method for obtaining monochromatic light emission data of each color will be described. The method of obtaining monochromatic light emission of each primary color differs depending on the characteristics of the display as the object to be measured and the situation where the correction data is acquired, and therefore will be described in the following order according to the characteristics and the situation of the display. (1) When the object to be measured is a display using a white light emitting backlight (such as a cold cathode tube), (2) the object to be measured is a display having an optical block (such as a rear projection television), and a liquid crystal When the correction data is acquired in a black state where all the shutters are closed. (3) The correction object is acquired in a black state where the object to be measured is a liquid crystal display and all the liquid crystal shutters are closed.

(1) When the object to be measured is a display using a white light emitting backlight (such as a cold cathode tube) To obtain monochromatic light emission of each primary color in a display using a white light emitting cold cathode tube as a backlight As shown in FIG. 4, any one of the red filter 31, the green filter 32, and the blue filter 33 is inserted in front of the color camera 2 and the spectral radiance meter 5, and the light after passing through the filter is measured. . In other words, the red filter 31 is attached when red light is emitted, the green filter 32 is attached when green light is emitted, and the blue filter 33 is attached when blue light is emitted. Thereby, even in a display using a cold-cathode tube or the like that emits white light as a backlight, pseudo-monochromatic light emission is realized, and correction data can be obtained.

  Note that the filters used for obtaining the monochromatic light emission such as the red filter 31, the green filter 32, and the blue filter 33 described above have the spectral characteristics as shown in FIGS. The one with the characteristic shall be used. In each figure of FIG. 5, the x-axis is the wavelength (nm) and the y-axis is the transmittance (%). FIG. 5A is a diagram showing the spectral characteristics of the red filter, which has a transmittance peak after 600 nm and transmits only light of this wavelength. FIG. 5B is a diagram showing the spectral characteristics of the green filter, which has a transmittance peak between 500 nm and 600 nm and transmits only light of this wavelength. FIG. 5C shows the spectral characteristics of the blue filter, which has a transmittance peak at 400 nm to 500 nm and transmits only light of this wavelength.

FIG. 6 shows an example of spectral radiance distribution of a display using a cold cathode tube when the above-described filter is used. In each figure of FIG. 6, the x-axis is the spectral radiance and the y-axis is W / sr / m ² (watts / steradian / square meter). FIG. 6A is a diagram showing a spectral radiance distribution when light obtained by causing a cold cathode tube to emit light is measured with a spectral radiance meter, which is a white spectral radiance distribution. FIG. 6B is a diagram showing the spectral radiance obtained by measuring the light of the cold cathode tube that has passed through the red filter with a spectral radiance meter, and has a red spectral radiance distribution. FIG. 6C is a diagram showing the spectral radiance measured by the spectral radiance meter of the light of the cold cathode tube that has passed through the green filter, and has a green spectral radiance distribution. FIG. 6D is a diagram showing the spectral radiance obtained by measuring the light of the cold cathode tube that has passed through the blue filter with a spectral radiance meter, and has a blue spectral radiance distribution. By using a filter capable of accurately separating the wavelengths of the primary colors so as to obtain the spectral radiance distributions shown in FIGS. 6B to 6D, it is possible to obtain pseudo-monochromatic emission of each primary color. It becomes possible. In this case, the primary color monochromatic filter may be a commercially available one or a specially manufactured product.

  In the above-described method, the red filter 31, the green filter 32, and the blue filter 33 are individually attached to the color camera 2 and the spectral radiance meter 5 when it is desired to emit each primary color in a single color. A rotating plate 35 having a red filter 31 ', a green filter 32', and a blue filter 33 'as shown in FIG. The rotating plate 35 is provided between the color camera 2 or the spectral radiance meter 5 and the object 20 to be measured, is automatically rotated at regular intervals, and the color camera 2 and the spectral radiance meter 5 change each color. An image of monochromatic light emission data is taken. According to this method, it is possible to automatically obtain single color emission data of each primary color without taking the trouble of changing the filter.

(2) When the object to be measured is a display having an optical block and the correction data is acquired in a black state in which all liquid crystal shutters are closed Among the displays having an optical block such as a rear projection television, in particular, the liquid crystal panel 3 When a single-color primary color is to be issued in a black state in which all liquid crystal shutters are closed in a three-plate projection method using two sheets, two sheets that transmit light of a color other than the color desired to emit a single color are transmitted. A light-shielding plate is inserted in front of or behind the liquid crystal panel to block the transmitted light other than the color to be emitted in a single color, and measure the slight light transmitted through the liquid crystal whose shutter is closed.

  FIG. 8 is a diagram showing a configuration example of a projection apparatus 40 of a three-plate type projection system. Light from the light source 41 is separated into three primary colors of red, green, and blue by dichroic mirrors 42 and 43, and each is provided for exclusive use. The light transmitted through the liquid crystal panels 44, 45, 46 is combined by the half mirrors 47, 48, and enlarged and projected onto a display (not shown) by the projection lens 49. In FIG. 8, red light is a long two-dot chain line, green light is a long chain line, and blue light is a broken line.

  FIG. 8 shows a configuration example in the case where it is desired to obtain red monochromatic light emission. A light shielding plate is provided in front of the liquid crystal panel 45 that transmits blue light and the liquid crystal panel 46 that transmits green light among the projection light from the light source 41. 50 is inserted to block blue light and green light. Thereby, the light projected on the display (not shown) through the projection lens 49 becomes red monochromatic light. In this way, by inserting a light blocking plate in front of or behind the liquid crystal panel that transmits light other than the color desired to emit a single color, and measuring the light projected on the display, even in a black state where all the liquid crystal shutters are closed, It becomes possible to acquire correction data for red single color emission. Similarly, when it is desired to obtain correction data at the time of green monochromatic light emission, the light shielding plates 50 may be inserted before and after the liquid crystal panel 45 that transmits blue light and the liquid crystal panel 44 that transmits red light. In order to obtain correction data, the light shielding plates 50 may be inserted before and after the liquid crystal panel 46 that transmits green light and the liquid crystal panel 44 that transmits red light.

(3) When the object to be measured is a liquid crystal display and the correction data is acquired in a black state in which all the liquid crystal shutters are closed. In this case, the liquid crystal panel with the shutters closed is the same as in the case of the three-plate projection device. This is done by measuring a small amount of light from the backlight 60 that passes through. In a liquid crystal display, when acquiring correction data in a black state in which all liquid crystal shutters are closed, a color filter composed of three primary colors R, G, and B arranged in front of the liquid crystal shutter is used as a red filter or a green filter. Or, instead of the monochromatic filter of the blue filter, a slight amount of light from the backlight transmitting the liquid crystal is measured.

  FIG. 9A is a diagram illustrating a configuration example of a conventional liquid crystal panel. The light from the backlight 60 is transmitted through the liquid crystal shutter 61 and is colored through the color filter 62 having three colors of R, G, and B. In such a configuration, in order to acquire single color emission data of each primary color in the black state in which all the liquid crystal shutters 61 are closed, a single color filter of a color desired to emit single color is installed instead of the color filter 62. FIG. 9B shows a configuration example when it is desired to realize red monochromatic light emission, and a red filter 63 is attached instead of the color filter 62. In this state, by measuring the light leaking from the backlight with all the liquid crystal shutters 61 closed, it is possible to acquire single-color emission data for each primary color even in the black state. Similarly, when it is desired to obtain correction data for green single color light emission, the green filter 64 is installed in place of the color filter 62, and when it is desired to obtain correction data for blue single color light emission, the blue filter 65 is replaced with the color filter 62. It can be installed instead.

Next, calibration processing, correction processing, and luminance / chromaticity conversion for calculating luminance / chromaticity will be described. In order to calculate brightness and chromaticity, camera black level correction, shading correction, and crosstalk correction are required.In the previous stage, camera black level calibration, shading calibration, crosstalk calibration, Luminance / chromaticity calibration is required. Details of each process will be described below in the order of calibration and correction.
(1) Camera black level calibration Normally, even when light does not enter the color camera 2 (the lens 3 is capped), a slight output level is detected. For this reason, in a state where the lens 3 is capped, the output value (for example, 0 to 255 in the case of 8 bits) is stored in the HDD 10 as correction data.

(2) Shading calibration of the camera (lens) Due to the influence of the distortion of the lens 3 of the color camera 2 and the like, a decrease in luminance occurs in the peripheral portion of the image captured by the color camera 2. If this decrease in luminance is not corrected, accurate two-dimensional luminance and chromaticity cannot be calculated. In the shading calibration, a uniform object such as an integrating sphere is usually imaged by the color camera 2, and ratio data (two-dimensional) with the maximum value in the field of view of the color camera 2 being 1 is stored in the HDD 10. When an integrating sphere or the like cannot be prepared, a virtually uniform light source is obtained by moving the lens closer to the light source or installing a diffuser plate in front of the light source.

(3) Camera Crosstalk Calibration Generally, the spectral characteristics of the red, green, and blue color filters of the color camera 2 and the spectral characteristics of the object 20 to be measured do not match. That is, the green component of the object 20 to be measured leaks not only to the green output of the color camera 2 but also to the red and blue outputs, and this effect is called crosstalk. For this reason, it is necessary to eliminate leakage of unnecessary components from the measured value. Assuming that the object to be measured 20 is, for example, a panel portion of a liquid crystal monitor, the following matrix data is obtained as crosstalk calibration by measuring for each single color of red, green, and blue. save.

here,
R / G is obtained by taking an image of the object 20 to be measured emitted in a single green color with the color camera 2 and calculating the red camera output from the output of the color camera 2.
R / B is obtained by taking an image of the object 20 to be measured emitted with a single blue color with the color camera 2 and calculating the red camera output from the output of the color camera 2.
G / R is obtained by taking an image of the object 20 to be measured, which has been emitted with a single red color, with the color camera 2, and calculating the green camera output from the output of the color camera 2.
G / B is an image of the object 20 to be measured that is emitted in a single blue color, captured by the color camera 2, and the green camera output is calculated from the output of the color camera 2.
B / R is obtained by taking an image of the object 20 to be measured, which has been emitted in a single red color, with the color camera 2, and calculating the blue camera output from the output of the color camera 2.
B / G is obtained by taking an image of the object 20 to be measured emitted with a single green color with the color camera 2 and calculating the blue camera output from the output of the color camera 2. We will use the method.

(4) Camera Brightness / Chromaticity Calibration When measuring the brightness and chromaticity with the color camera 2, the brightness and chromaticity data used as the reference for the red, green and blue components of the measurement object 20 are required. Become. The reference luminance data and chromaticity data can be obtained by measuring the monochromatic emission of each color with the spectral radiance meter 5. In order to obtain monochromatic light emission of each color, the above-described method is used. At the same time, the red camera output value (for example, 0 to 255 in the case of 8 bits), the green camera output value of the green component, and the blue output value of the blue component of the measurement target 20 are stored in the HDD 10. However, when only the luminance is measured by the color camera 2, only the luminance data of the measurement target 20 is required as the reference data. In this case, only white or green emission data need be acquired.

となる。 As described above, all necessary correction data is stored in the HDD 10. Next, processing for calculating luminance and chromaticity in actual measurement will be described. The following processing is performed for any one pixel in the two-dimensional flat display to be measured. When the measured object 20 is measured with the color camera 2 and the red, green, and blue output values are r, g, and b, and the black level calibration values are rb, gb, and bb, black level correction is performed. ceremony,

It becomes.

Furthermore, when the calibration values after shading calibration are rs, gs, and bs, the shading correction formula is

  Furthermore, the crosstalk correction formula is obtained as the following formula for the first time when r ′, g ′, and b ′ are set as pure red, green, and blue components of the measurement target 20 from the crosstalk calibration.

Here, correction data of each primary color obtained by the brightness / chromaticity calibration is stored in the HDD 10 as follows.
Spectral radiance meter Red Green Blue Chromaticity xr, yr xg, yg xb, yb
Luminance Yr Yg Yb

Color camera Red Green Blue Camera output data rc gc bc
Here, what is important is that the position and measurement area measured by a measuring instrument such as a spectral radiance meter coincide with the position and measurement area measured by the color camera 2.

  The red, green, and blue tristimulus values of the object 20 to be measured are Xr, Xg, Xb, Yr, Yg, Yb, Zr, Zg, Zb, and the light emission ratio of the object 20 to be measured is r, g, b. Assuming that the tristimulus values of the object 20 to be measured are X, Y, and Z, the following equation is known.

  And general formula

  Using,

And the following general formula:

To expand (Equation 7).

  From the above, the obtained luminance Y and chromaticity x, y are expressed by the following (Equations 9, 10, 11).

  By doing so, it is possible to correct the luminance and chromaticity of any one pixel of the measurement object 20 by performing a predetermined calibration using the color camera 2.

  According to the embodiment described above, a display having a single-color emission data of each primary color in a display using a cold cathode tube that cannot emit each primary color as a light source and an optical block such as a rear projection television. The acquisition of single-color emission data for each primary color in the black state, and the acquisition of single-color emission data for each primary color in the black state on a liquid crystal display can be performed only with a luminance and chromaticity measuring device such as a spectral luminance radiometer and a color camera. Become.

  In addition, it is possible to perform brightness and chromaticity measurement processing without using multiple filters (usually three tristimulus filters are used), so there is no need to consider the rotation time of the filter, and it is possible to measure at high speed. There is an effect that it is possible to measure the object 20. When this measurement process is used, the current measurement time is about 1 second. However, if the calculation performance of the computer is improved, the measurement process can be further accelerated.

  Further, since it is not necessary to switch a plurality of filters, it is not necessary to create a movable mechanism for the filter. Thereby, the number of parts can be reduced, and there is an effect that maintenance can be easily performed even during maintenance work of the apparatus.

  Further, all the calibration processing can be performed at the user level by using only a predetermined application program, and the calibration processing according to the measurement target 20 can be performed. In addition, since the luminance and chromaticity measuring device 1 has a simple configuration and does not use a special light source or device, commercially available products can be used for all the devices that constitute the luminance and chromaticity measuring device 1, so that There is an effect that the device can be manufactured at a low cost.

  In the above-described embodiment, the correction result is obtained by performing the calibration process on one pixel. However, even when the entire display is measured as the two-dimensional data of the object 20 to be measured, the pixel to be measured A correction result can be obtained by performing the same calibration process on all of them.

  In the above-described embodiment, the measurement is performed using the color camera 2, but the same measurement and calculation are performed using a photoelectric element such as a photosensor provided with red, green, and blue filters. The luminance and chromaticity of the measurement object may be calculated. When such a photoelectric element is used, there is an effect that the luminance and chromaticity of the object to be measured can be measured with higher accuracy.

  In the above-described embodiment, the detection data of both luminance and chromaticity are calibrated. For example, only luminance data for each primary color of red, green, and blue is obtained based on the imaging signal, and each of the data is obtained. Only the luminance of the primary color may be calibrated to obtain a measured value of luminance.

  In the above-described embodiment, the luminance and chromaticity are measured from the image displayed on the display device. However, the present invention is also applicable to the case of measuring and measuring other objects to be measured.

It is a block diagram which shows the structural example of the brightness | luminance chromaticity measuring apparatus by one embodiment of this invention. It is a block diagram which shows the example of an internal structure of the brightness | luminance chromaticity measuring device by one embodiment of this invention. It is a flowchart which shows the procedure of the correction data acquisition by one embodiment of this invention. It is explanatory drawing which shows the structural example in case the to-be-measured object by one embodiment of this invention is a cold cathode tube. It is explanatory drawing which shows the spectral characteristic of each primary color by one embodiment of this invention. It is explanatory drawing which shows the example of distribution of the spectral radiance of the cold cathode tube by one embodiment of this invention. It is explanatory drawing which shows the structural example at the time of using the rotating plate by one embodiment of this invention. It is explanatory drawing which shows the structural example of the 3 plate type | mold projection apparatus by one embodiment of this invention. It is explanatory drawing which shows the structural example of the liquid crystal panel by one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Luminance chromaticity measuring apparatus, 2 ... Color camera, 3 ... Lens, 4 ... Computer, 5 ... Spectral radiance meter, 10 ... HDD, 11 ... Memory, 12 ... Camera interface board, 13 ... CPU, 14 ... Display, DESCRIPTION OF SYMBOLS 15 ... Keyboard, 16 ... Mouse, 17 ... System bus, 20 ... Object to be measured, 31 ... Red filter, 32 ... Green filter, 33 ... Blue filter, 35 ... Rotating plate, 41 ... Light source, 42, 43 ... Dichroic mirror 44-46 ... liquid crystal panel, 47, 48 ... half mirror, 49 ... projection lens, 60 ... backlight, 61 ... liquid crystal shutter, 62 ... color filter, 63 ... red filter, 64 ... green filter, 65 ... blue filter

Claims (4)

An object to be measured is caused to emit a single color to each primary color, and each primary color emitted by the single color is imaged with a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are used as reference values for luminance and chromaticity calculation. In the calibration method in luminance and chromaticity measurement, storing the correction value of each primary color calculated based on the reference value,
When the object to be measured is a display using a white light source, correction data is obtained by attaching a filter for each primary color to the luminance chromaticity measuring device and the color camera and emitting each primary color in a single color. A calibration method for measuring luminance and chromaticity. In the calibration method in luminance and chromaticity measurement according to claim 1,
A rotating plate on which the primary color filters are arranged;
A correction method in luminance and chromaticity measurement, wherein the correction data is acquired by causing each of the primary colors to emit a single color by rotating the rotating plate. An object to be measured is caused to emit a single color to each primary color, and each primary color emitted by the single color is imaged with a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are used as reference values for luminance and chromaticity calculation. In the calibration method in luminance and chromaticity measurement, storing the correction value of each primary color calculated based on the reference value,
When the object to be measured is a projection device including three liquid crystal panels and the correction data in a black state in which all liquid crystal shutters are closed is obtained,
Among the three liquid crystal panels, correction data is obtained by emitting a single color of each primary color by inserting a light shielding plate in front or behind two liquid crystal panels that transmit colors other than the color for which single color emission is desired. A calibration method for measuring luminance and chromaticity, characterized by: An object to be measured is caused to emit a single color to each primary color, and each primary color emitted by the single color is imaged with a luminance chromaticity measuring device and a color camera, and the measurement values obtained by the imaging are used as reference values for luminance and chromaticity calculation. In the calibration method in luminance and chromaticity measurement, storing the correction value of each primary color calculated based on the reference value,
When the object to be measured is a liquid crystal display including color filters for each primary color, and when obtaining correction data in a black state in which all liquid crystal shutters are closed,
A calibration method in luminance and chromaticity measurement, wherein correction data is obtained by emitting a single color of each primary color by using a single color filter of each primary color instead of the color filter of each primary color.

Images