JP2009186284A - Device and method for measuring chromaticity ,and device and method for calibration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for measuring chromaticity which enable highly-accurate and quick measurement of chromaticity, and a device and a method for calibrating the chromaticity measuring device. <P>SOLUTION: A tristimulus values direct reading type measuring unit 2 includes a tristimulus values direct reading type sensor 21, a transmittance operation means 224 which calculates the transmittance of a liquid crystal panel, a corrective value storage means 222 which stores a first corrective matrix based on the chromaticity at an inflection point of a chromaticity change curve of each color light and a second corrective matrix corresponding to each color based on the chromaticity at a black presenting point, a maximum brightness point of each color and the inflection point of each color, a transmittance determining means 225 which compares the transmittance calculated by the transmittance operation means 224 with changeover transmittance, and a measured value calculating means 226 which compensates tristimulus values of each color individually by using the first corrective matrix in the case when the transmittance is smaller than the changeover transmittance and by using the second corrective matrix corresponding to each color in the case when the transmittance is larger than the changeover transmittance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chromaticity measuring device that measures the chromaticity of each color emitted from a display device, a chromaticity measuring method, a calibration device that calibrates the chromaticity measuring device, and a calibration method.

Conventionally, in a display device such as a projector that emits an optical image, chromaticity measurement is performed in order to confirm the chromaticity characteristics of each emitted color. For the implementation of this chromaticity measurement, a spectroscopic measuring instrument or a tristimulus value direct reading measuring instrument is used. Here, in order to measure the chromaticity characteristics of a display device that is a product such as a production line in a factory, it is preferable to use an inexpensive measuring device that can measure quickly and is expensive and requires a long time for measurement. It is common to use a tristimulus value direct reading type measuring instrument rather than a type measuring instrument. On the other hand, a spectroscopic measuring instrument is used as a standard measuring instrument when calibrating a tristimulus value direct reading measuring instrument.
In the chromaticity measurement of the display device by such a tristimulus value direct reading type measuring instrument, the value obtained by the measurement is corrected by a correction value set using the spectroscopic type measuring instrument, and the chromaticity of each color is measured. (For example, refer to Patent Document 1).

The device described in Patent Document 1 measures image light output from a projector using a reference device and a tristimulus value direct reading type measuring device. Then, based on the measurement values measured by the reference unit and the tristimulus value direct reading type measuring device, the correction coefficient and the correction plane coefficient in the tristimulus value direct reading type measuring device are calculated. Thereafter, the chromaticity of the projector to be inspected is measured by a tristimulus value direct reading type measuring device in which the correction coefficient and the correction plane coefficient are set. At this time, a correction coefficient is calculated based on the following equation.

In the above equation (1), X _{0_r100} , X _{0_g100} , and X _{0_b 100} are measured values of tristimulus values in the reference device, respectively, and X _{m_r100} , X _{m_g100} , and X _{m_b100} are tristimulus values in the tristimulus value direct reading type measuring device. Is the measured value.

JP 2007-93477 A

  By the way, in a device such as a liquid crystal projector that controls brightness by a liquid crystal panel, there is a change in the spectral peak wavelength of the light source and a change due to the brightness of the spectral profile of the light source for each device. For example, when red (R), green (G), and blue (B) are each changed from 0% to 100% on the color coordinate, the color coordinate change of each color changes linearly due to the change in optical rotation dispersion characteristics. However, it is known that the curve changes in the vicinity of 100% of a single color. Therefore, when the correction coefficient is obtained as in equation (1) of Patent Document 1, there is a problem that an error occurs because the optical rotatory dispersion characteristic is not considered.

  In view of the above problems, the present invention provides a chromaticity measuring device, a chromaticity measuring method, a calibrating device for calibrating the chromaticity measuring device, and a calibration method capable of measuring chromaticity with high accuracy and speed. The purpose is to provide.

  The chromaticity measuring apparatus according to the present invention modulates a plurality of color lights according to image information and changes each color light from a minimum brightness point where the brightness is minimum to a maximum brightness point where the brightness is maximum. A chromaticity measuring device for measuring the chromaticity of light output from a display device having a light modulation element in which a change curve on a color coordinate changes at a predetermined inflection point, A color measuring unit that receives each color light output from the display device and measures the chromaticity of the received color light, and a transmittance calculation unit that calculates the transmittance of each color light transmitted through the light modulation element; First correction matrix based on chromaticity at three inflection points corresponding to each color light, and corresponding to each color light based on chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point Correction value for storing three second correction matrices A memory means, a transmittance judging means for comparing the transmittance with a predetermined threshold value, and judging the magnitude relationship thereof, and when the transmittance judging means judges that the transmittance is smaller than the threshold value. In the first correction matrix, the transmittance is determined to be greater than the threshold value by the first correction unit that corrects the chromaticity of each color light measured by the color measurement unit and the transmittance determination unit. In this case, the second correction matrix includes second correction means for correcting the chromaticity of each color light measured by the color measurement means.

Here, examples of the light modulation element include a liquid crystal panel. In such a liquid crystal panel, the alignment of the liquid crystal changes depending on the applied voltage, and the light transmittance changes. For example, when the applied voltage is increased, there is almost no light transmitted through the liquid crystal panel and the brightness is minimized, and when the applied voltage is decreased, the brightness increases because more light passes through the liquid crystal panel. In addition, such a liquid crystal panel is generally formed so that light having a wavelength of 550 nm that can be most perceived by human eyes is transmitted best at 0 V where the brightness is maximum, that is, the light transmittance is maximum. ing. When the voltage applied to the liquid crystal panel is increased from the state where the light transmittance is maximum, the light transmittance decreases as shown in FIG. FIG. 1 is a diagram showing the wavelength and transmittance through the liquid crystal panel.
As shown in FIG. 1, when the voltage applied to the liquid crystal panel is increased, the wavelength range that easily passes through the liquid crystal panel also changes. In other words, the transmittance in the liquid crystal panel changes for each voltage. Therefore, when the voltage applied to each liquid crystal panel is reduced from a black display state in which each color light does not pass at all, and the coordinates (x, y) of each color light that change at that time are expressed as change curves on the color coordinates, FIG. As shown in FIG. FIG. 2 is a chromaticity diagram showing change curves on the color coordinates when the brightness of each color light is individually changed from the liquid crystal panel. FIG. 3 is an enlarged view of the red change curve in FIG. FIG. 4 is an enlarged view of the green change curve in FIG. FIG. 5 is an enlarged view of the blue change curve in FIG.
As shown in FIG. 2 to FIG. 5, when the voltage applied to the liquid crystal panel corresponding to green, for example, is decreased from the black display point O, it does not change linearly, but changes in curve at the inflection point _Gmid. It becomes. Therefore, as in the prior art, the tristimulus values of the maximum brightness points R _max , G _max , B _max of each color light are measured by the color measuring means, and one correction matrix M calculated from these values is measured. the _{_} other, the method for correcting the measured value, an error occurs.

On the other hand, in the present invention, the inflection points R _mid and G _mid shown in FIGS. 2 to 5 are obtained when the transmittance is smaller than a predetermined threshold according to the transmittance which is a ratio of passing through the light modulation element. , B _mid , when the measured value is corrected by the first correction matrix and the transmittance is larger than a predetermined threshold, the black display point O which is the minimum brightness point, the inflection point R _mid of the opposite color, The measured value is corrected by the second correction matrix based on G _mid , B _mid , and the maximum brightness points R _max , G _max , B _max of the corresponding color.
For this reason, even when the change curve of each color becomes a curve that changes in a non-linear manner at the inflection point, when measuring dark color light whose transmittance is up to a predetermined threshold, and bright color light whose transmittance is greater than the predetermined threshold The optimum correction value can be properly used depending on whether the measurement is performed. Therefore, the measured value can be corrected to a more accurate chromaticity corresponding to the change curve. Therefore, the chromaticity of the display device can be measured more accurately and promptly without using an expensive device such as a spectroscopic measuring instrument.

In the chromaticity measuring apparatus of the present invention, the transmittance calculating means calculates a ratio of chromaticity of light to be measured to chromaticity at the maximum brightness point of each color as the transmittance, and the transmittance It is preferable that the determination unit compares the transmittance and the switching transmittance with a switching transmittance which is a ratio of the chromaticity at the inflection point to the chromaticity at the maximum brightness point of each color as a threshold value.
According to this invention, the transmittance calculating means calculates a transmittance that is a ratio of the chromaticity of the light to be measured to the chromaticity at the maximum brightness point of each color, and the transmittance and the maximum brightness of each color. The magnitude of the switching transmittance, which is the ratio of the inflection point of each color to the chromaticity at the point, is compared. That is, in FIG. 2 through FIG. 5, the black display point O from the inflection point _R mid of each _color, G _mid, for the relatively dark colors light until _{B mid,} inflection point _{R mid, G mid,} The measurement value is corrected by the first correction matrix based on _Bmid . Further, the relatively bright color lights between the inflection points R _mid , G _mid , B _mid and the maximum brightness points R _max , G _max , B _max are corrected by the second correction matrix. That is, the color coordinate change of each color changes substantially linearly from the black display point O to the inflection points R _mid , G _mid , and B _mid . Therefore, when the transmittance is smaller than the switching transmittance, the measured value is corrected by the first correction matrix calculated based on the inflection points R _mid , G _mid , and B _mid, and the change curve of each color is met. More appropriate chromaticity correction can be performed. On the other hand, in the case of color light brighter than the inflection points R _mid , G _mid , and B _mid (color light up to the maximum brightness point), the maximum brightness points R _max and G _{max are obtained} from the inflection points R _mid , G _mid , and B _mid. , B _max change substantially linearly. Therefore, when the magnetic permeability is larger than the switching magnetic permeability, the maximum brightness is obtained from the inflection points R _mid , G _mid , B _mid by correcting the chromaticity of each color by the second correction matrix corresponding to each color. More appropriate chromaticity correction can be performed in accordance with change curves of the points R _max , G _max , and B _max .

  Further, the chromaticity measurement method of the present invention optically modulates a plurality of color lights according to image information, and each color light from a minimum brightness point where the brightness is minimum to a maximum brightness point where the brightness is maximum. This is a chromaticity measurement method for measuring the chromaticity of light output from a display device having a light modulation element in which a change curve on a color coordinate changes at a predetermined inflection point when changed. And receiving each color light output from the display device, measuring the chromaticity of the color light, calculating the transmittance of each color light transmitted through the light modulation element, and calculating the calculated transmittance and a predetermined value. When the transmittance is smaller than the threshold, the measured chromaticity is calculated with the first correction matrix based on the chromaticity at the three inflection points corresponding to each color light. If the transmittance is greater than the threshold, the minimum brightness point, the previous Maximum brightness point, and based on the chromaticity of the inflection point, three second correction matrix corresponding to each color light, and correcting the measured chromaticity of each color light, respectively.

  According to this invention, similarly to the above-described invention, the measurement value is corrected with one of the first correction matrix and the second correction matrix in accordance with the light transmittance to the light modulation element. Thereby, even when the color coordinate change of each color becomes a non-linear curve, when measuring dark color light whose transmittance is up to a predetermined threshold and when measuring bright color light whose transmittance is higher than the predetermined threshold, Appropriate chromaticity correction according to the change curve can be performed. Therefore, the chromaticity of the display device can be measured more accurately and promptly without using an expensive device such as a spectroscopic measuring instrument.

  The calibration apparatus of the present invention optically modulates a plurality of color lights according to image information, and changes each color light from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. Calibration to calibrate a chromaticity measuring device that measures the chromaticity of light output from a display device having a light modulation element whose change curve on a color coordinate changes at a predetermined inflection point A reference display device that outputs each color light having a reference chromaticity, and the brightness of the light output from the reference display device from the minimum brightness point to the maximum brightness point along the change curve. Brightness control means for changing to, reference chromaticity measurement means for measuring the reference chromaticity of each color light output from the reference display device, measured by the reference chromaticity measurement means and the chromaticity measurement device, The minimum brightness point of each color light, the maximum brightness , And measurement value recognition means for recognizing each measurement value of chromaticity at the inflection point, and measurement by the chromaticity measurement device based on the measurement values of chromaticity at the three inflection points corresponding to each color light. Chromaticity measurement values at the minimum brightness point, the maximum brightness point, and the inflection point corresponding to each color light And a second correction calculation means for calculating a second correction matrix for correcting the measurement values measured by the chromaticity measuring device corresponding to each color light.

According to this invention, the chromaticity of each color light of the light emitted from the reference display device that has already been adjusted, for example, is measured by the reference chromaticity measuring means and the tristimulus value measuring device. At this time, the brightness control means changes the brightness of each color light emitted from the reference display device by changing the voltage applied to the light modulation element. Then, the measured value recognizing means measures the black display point O and the inflection points R _mid , G of each color light in the chromaticity diagrams of FIGS. 2 to 5 measured by both the reference chromaticity measuring means and the color measuring means. _Mid , B _mid , and chromaticity at the maximum brightness points R _max , G _max , B _max of each color light are recognized. The first correction calculation unit corrects the measurement value of the color measurement unit to the measurement value of the reference chromaticity measurement unit based on the measurement values of both the reference chromaticity measurement unit and the color measurement unit at the three inflection points. To calculate a first correction matrix. Further, the second correction calculation means performs black display point O, black display point O, inflection points R _mid , G _mid , B _mid , maximum brightness point R _max , G for each color of R, G, B. Based on _max and _Bmax , a second correction matrix for correcting the measurement value of the color measurement unit to the measurement value of the reference chromaticity measurement unit is calculated.
Thus, the calibration device can easily obtain the first correction matrix and the second correction matrix by calculation. In addition, by recording these correction matrices in a correction storage means that can be read by the chromaticity measuring device, the correction of the measured value can be immediately calculated without calculating the correction value again by the chromaticity measuring device. And the chromaticity of the display device to be measured can be easily measured. Further, even when the change curves of the respective colors change nonlinearly as shown in FIGS. 2 to 5, the first correction matrix and the second correction matrix are subdivided into two regions with the inflection point as a boundary. Since the correction matrix is calculated, it is possible to correct the chromaticity measured by the color measuring means to approximately approximate the color coordinate change curve. Therefore, it is possible to perform appropriate correction with less error and to accurately measure chromaticity.

In the calibration device of the present invention, the switching transmittance, which is the ratio of the chromaticity measurement value at the inflection point to the chromaticity measurement value at the maximum brightness point measured by the chromaticity measurement device, is calculated. It is preferable to provide a switching transmittance calculation means.
In this invention, by calculating the switching transmittance by the calibration device, when correcting the chromaticity measured by the chromaticity measuring device, processing such as calculating the switching transmittance is not required, and more rapid measurement is possible. Is possible. The switching transmittance calculating means calculates a ratio of the chromaticity measurement value at the inflection point to the chromaticity measurement value at the maximum brightness point. Therefore, by comparing the transmittance calculated by the chromaticity measuring device with the switching transmittance, in the change curve in the chromaticity diagram, the dark side near the black display point O with the inflection point as a boundary, the inflection It can be classified into the light color side near the maximum brightness point from the point, and the chromaticity can be corrected with a more appropriate correction value in the chromaticity measuring device.

In the calibration apparatus of the present invention, the chromaticity measuring device and the reference chromaticity measuring means are arranged in parallel in a direction substantially orthogonal to the main optical axis of the light emitted from the reference display device, It is preferable that a translation control unit that translates the chromaticity measuring device and the reference chromaticity measuring unit in a direction substantially orthogonal to the main optical axis is provided.
In the present invention, the color measuring unit and the reference chromaticity measuring unit can be arranged on the same axis as the main optical axis by moving in parallel. Therefore, for example, after the measurement of the color measuring means is completed in a state where the color measuring means is arranged on the main optical axis, the reference chromaticity measuring means is translated on the main optical axis by the parallel movement control means. Thus, the light measurement conditions in the color measurement unit and the reference chromaticity measurement unit can be made the same. Therefore, the measurement accuracy of each color light by the color measurement unit can be made closer to the reference chromaticity measurement unit, and a correction matrix for more accurate chromaticity measurement can be calculated.

  Then, the calibration method of the present invention optically modulates a plurality of color lights according to image information, and changes each color light from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. Calibration to calibrate a chromaticity measuring device that measures the chromaticity of light output from a display device having a light modulation element whose change curve on a color coordinate changes at a predetermined inflection point A method of outputting each color light having a reference chromaticity from a reference display device while changing the brightness from the minimum brightness point to the maximum brightness point along the change curve. Each color light is measured by the chromaticity measuring device and the reference chromaticity measuring unit, and measured by the chromaticity measuring device and the reference chromaticity measuring unit, the minimum brightness point and the maximum brightness point of each color light , And measured chromaticity at the inflection point Recognizing and calculating a first correction matrix based on the measured values of chromaticity at the three inflection points corresponding to each color light, the minimum brightness point corresponding to each color light, the maximum brightness point, The second correction matrix corresponding to each color light is calculated based on the chromaticity measurement value at the inflection point.

  According to this invention, similarly to the above-described invention, the first correction matrix and the second correction matrix can be easily obtained by calculation. In addition, by recording these correction matrices in a correction storage means that can be read by the chromaticity measuring device, the correction of the measured value can be immediately calculated without calculating the correction value again by the chromaticity measuring device. And the chromaticity of the display device to be measured can be easily measured. Further, even when the change curves of the respective colors change nonlinearly as shown in FIGS. 2 to 5, the first correction matrix and the second correction matrix are subdivided into two regions with the inflection point as a boundary. Since the correction matrix is calculated, it is possible to correct the chromaticity measured by the color measuring means to approximately approximate this change curve. Therefore, it is possible to perform appropriate correction with less error and to accurately measure chromaticity.

[First embodiment]
Hereinafter, a calibration apparatus and a chromaticity measurement apparatus according to a first embodiment of the present invention will be described with reference to the drawings.

[Configuration of calibration device]
FIG. 6 is a block diagram showing a configuration of a calibration apparatus according to an embodiment of the present invention.
In FIG. 6, reference numeral 1 denotes a calibration device. The calibration device 1 includes a tristimulus value direct-reading type measuring device 2 as a chromaticity measuring device that is symmetric to the calibration, a reference device 3 as a reference chromaticity measuring means, A calibration stage 4 on which the tristimulus value direct-reading measuring instrument 2 and the reference instrument 3 are placed, a projector 5 as a reference display device, and a calibration control device 6 are provided.

FIG. 7 is a block diagram showing a schematic configuration of a tristimulus value direct reading type measuring instrument. FIG. 8 is a block diagram showing a configuration of a tristimulus value direct reading type sensor in the tristimulus value direct reading type measuring instrument.
As shown in FIG. 7, the tristimulus value direct reading type measuring instrument 2 includes a tristimulus value direct reading type sensor 21 as a color measuring unit and an inspection control unit 22. Details of the configuration of the inspection control unit 22 will be described later.
As shown in FIG. 8, the tristimulus value direct reading sensor 21 includes a diffusion plate 211, RGB filters 212, a photodiode (light source switching element) 213, a primary correction circuit 214, and a secondary correction circuit 215. .
The light emitted from the reference projector 5 toward the tristimulus value direct reading type measuring instrument 2 passes through the diffusion plate 211 of the tristimulus value direct reading type sensor 21 and passes through the RGB filters 212. The light passing through each filter 212 is converted into an electric signal by the photodiode 213. The exchanged electric signal is subjected to amplifier adjustment on the primary correction circuit 214. At this time, the measurement range is determined by the gain of the amplifier. Then, the RGB signal is converted into tristimulus values XYZ by the secondary correction circuit 215.
The tristimulus values XYZ are appropriately displayed on a display screen provided in the tristimulus value direct reading type sensor 21 and are output to the examination control unit 22. The inspection control unit 22 includes an output terminal (not shown), and is configured to output tristimulus values XYZ to the calibration control device 6 from the output terminal.
In the present embodiment, the tristimulus value direct-reading type sensor 2 and the test control unit 22 are illustrated as an example, but the tristimulus value direct-reading type measuring instrument 2 is not limited thereto. The tristimulus value direct-reading type measuring instrument 2 may be configured by the value direct-reading type sensor 21 and a personal computer that is communicably connected to the tristimulus value direct-reading type sensor 21 via a cable line.

As the reference device 3, a spectral color measuring device capable of measuring a color with higher accuracy than the tristimulus value direct reading type sensor 21 is usually used, but a reference tristimulus value direct reading type measuring device may be used. . The measurement data of the reference device 3 can also be output to the calibration control device 6 via the output terminal.
The reason for calibrating the tristimulus value direct reading type measuring instrument 2 according to the reference unit 3 is as follows. The tristimulus value direct reading type measuring instrument 2 is less expensive than a spectroscopic sensor. Therefore, if the tristimulus value direct reading type measuring instrument 2 is used in an inspection process in a production line such as the projector 5, many tristimulus value direct reading type measuring instruments 2 can be prepared, and the efficiency of the inspection process can be improved. At this time, by calibrating each tristimulus value direct-reading type measuring instrument 2 according to the reference unit 3, it is possible to eliminate variations (errors) in the measured values of each tristimulus value direct-reading type measuring instrument 2. Test objects such as 5 can be correctly evaluated.

  The calibration stage 4 is configured to be slidable in a direction substantially orthogonal to the main optical axis of the reference projector 5 by a control signal output from the calibration control device 6. Thereby, the tristimulus value direct-reading measuring instrument 2 and the reference instrument 3 on the calibration stage 4 can be alternately arranged on the front surface of the projector 5.

The projector 5 is a measured object measured and evaluated by the calibrated tristimulus value direct-reading type measuring instrument 2, and the drive is controlled by the calibration control device 6 during the calibration process.
FIG. 9 is a block diagram showing a schematic configuration of the optical system 51 in the projector 5.
As shown in FIG. 9, the optical system 51 in the projector 5 includes a light source lamp 52, a color separation optical system 53, a relay optical system 54, and a liquid crystal panel 55 (55R, 55G, 55B) as a light modulation element. A cross dichroic prism 56 and a projection optical system 57 are provided.

In such an optical system 51 of the projector 5, the light emitted from the light source lamp 52 is separated into RGB color lights by the color separation optical system 53. Specifically, the color separation optical system 53 includes a first dichroic mirror 531, a second dichroic mirror 532, and a reflection mirror 533. The first dichroic mirror 531 transmits red light and reflects light of other wavelengths. The red light transmitted through the first dichroic mirror 531 is reflected by the reflection mirror 533 and enters the red liquid crystal panel 55R. The second dichroic mirror 532 reflects green light among light reflected by the first dichroic mirror 531 and transmits blue light. The green light reflected by the second dichroic mirror 532 is directly incident on the green liquid crystal panel 55G. The blue light transmitted through the second dichroic mirror 532 is guided to the blue liquid crystal panel 55B by the reflection mirrors 541 and 542 of the relay optical system 54 and a relay lens (not shown).
The liquid crystal panel 55 (55R, 55G, 55B) optically modulates each incident color light according to image information, and emits the light-modulated color light to the cross dichroic prism 56 side. Then, the cross dichroic prism 56 color-synthesizes each color light emitted from the liquid crystal panel 55 to form an optical image, and projects it from the projection optical system 57.

Here, each liquid crystal panel 55 in the projector 5 can adjust the spectral transmittance characteristics by changing various conditions such as the cell thickness, twist angle, and pretilde angle. In general, as shown in FIG. 1, each liquid crystal panel 55 has a peak wavelength of 550 (nm) when the drive voltage V = 0.0 (V) (hereinafter referred to as the minimum set voltage). The various conditions have been adjusted. Here, when the drive voltage is changed from 0.0 (V) to 5.0 (V) which is the maximum voltage on setting (hereinafter referred to as the maximum set voltage), as shown in FIG. Along with the decrease, the peak wavelength due to optical rotation dispersion shifts from 550 (nm) to the short wavelength side. Therefore, when the light output from the projector 5 is measured by the tristimulus value direct reading type measuring instrument 2 and the reference unit 3 and the drive voltage is changed, as shown in the chromaticity diagrams shown in FIGS. When the tristimulus values are displayed in color coordinates, they are displayed as nonlinear change curves. The driving voltages (hereinafter referred to as inflection setting voltages) corresponding to the inflection points R _mid , G _mid , and B _mid in the chromaticity diagrams of FIGS. 2 to 5 are set in advance for each liquid crystal panel 55. For example, in this embodiment, the red liquid crystal panel 55R and the green liquid crystal panel 55G correspond to the inflection points R _mid and G _mid in the chromaticity diagram when the driving voltage V is V = 3.0 (V). When the drive voltage is 2.0 (V), the color light corresponding to the inflection point B _mid in the chromaticity diagram is output from the blue liquid crystal panel 55B.

The calibration control device 6 is configured by a general computer including a CPU, a memory, and the like, and includes each unit as shown in FIG. 10 that is executed by incorporating a predetermined program. FIG. 10 is a block diagram showing a schematic configuration of the calibration control apparatus.
That is, as shown in FIG. 10, the calibration control apparatus 6 includes a stage control unit 61 as a parallel movement control unit, a projector control unit 62 as a brightness control unit, and a calibration target measurement value acquisition as a measurement value recognition unit. Means 63, reference device measurement value acquisition means 64 as measurement value recognition means, first correction calculation means 65, second correction calculation means 66, switching transmittance calculation means 67, and storage means 68. ing.

  The stage control means 61 controls the movement of the calibration stage 4. Specifically, when the stage control means 61 measures the image light from the projector 5 by the tristimulus value direct reading type measuring instrument 2, the tristimulus value direct reading type sensor 21 of the tristimulus value direct reading type measuring instrument 2 is used as the projector. The calibration stage 4 is moved to a state located in front of 5. Further, when the image light from the projector 5 is measured by the reference device 3, the calibration stage is moved to a state where the reference device 3 is positioned in front of the projector 5.

The projector control means 62 controls the driving of the projector 5. Specifically, the projector control means 62 performs control to emit image light of a predetermined test pattern image from the projector 5. Further, the projector control means 62 performs control to switch the drive voltage applied to the liquid crystal panel 55 and to emit image light with different brightness from the projector 5. Specifically, the projector control means 62 applies a maximum set voltage to each of the RGB liquid crystal panels 55 to emit black image light (image light corresponding to the black display point O in FIGS. 2 to 5). In a state in which the inflection setting voltage is applied to the red liquid crystal panel 55R, and the red light corresponding to the inflection point R _mid in FIG. 3 is emitted, the minimum setting voltage is applied to the red liquid crystal panel 55R, In a state in which red light having the maximum output (image light corresponding to the red maximum brightness point R _max in FIG. 3) is emitted, an inflection setting voltage is applied to the green liquid crystal panel 55G, and the inflection point G _mid is applied. In a state in which the corresponding green light is emitted, the lowest set voltage is applied to the green liquid crystal panel 55G, and the green light having the maximum output (image light corresponding to the green maximum brightness point G _max in FIG. 4) is emitted. Status The inflection setting voltage is applied to the blue liquid crystal panel 55B to emit blue light corresponding to the inflection point B _mid , and the minimum setting voltage is applied to the blue liquid crystal panel 55B to maximize the output. The state is sequentially switched to a state in which blue light (image light corresponding to the blue maximum brightness point B _max in FIG. 5) is emitted.

The calibration target measurement value acquisition means 63 controls the tristimulus value direct reading type sensor 21 of the tristimulus value direct reading type measuring instrument 2 to measure the chromaticity (tristimulus value XYZ) of the image light emitted from the projector 5. The tristimulus value XYZ input from the tristimulus value direct reading type measuring instrument 2 is acquired. At this time, the calibration target measurement value acquisition unit 63 recognizes the driving voltage of the liquid crystal panel 55 of the projector 5 controlled by the projector control unit 62, and each point O, R _mid , in the chromaticity diagrams of FIGS. _Tristimulus values corresponding to G _mid , B _mid , R _max , G _max , and B _max are acquired, respectively.

The reference device measurement value acquisition means 64 controls the reference device 3 to measure and acquire the chromaticity (tristimulus value XYZ) of the image light emitted from the projector 5. At this time, the reference device measurement value acquisition unit 64 corresponds to each point O, R _mid , G _mid , B _mid , R _max , G _max , and B _max in the chromaticity diagram in the same manner as the calibration target measurement value acquisition unit 63. Each tristimulus value to be acquired is acquired.

The first correction calculation unit 65 is based on the tristimulus values of the image light corresponding to the inflection points R _mid , G _mid , and B _mid measured by the calibration target measurement value acquisition unit 63 and the reference device measurement value acquisition unit 64. Thus, the first correction matrix M _dark is calculated by the following equation (2).

In the above equation (2), X _{0_r_mid} , Y _{0_r_mid} , and Z _{0_r_mid} are measured values obtained by measuring the tristimulus values of the image light corresponding to the inflection point R _mid with the reference device 3, X _{0_g_mid} , Y _{0_g_mid} , and Z _{0_g_mid} are , Measured values obtained by measuring the tristimulus value of the image light corresponding to the inflection point G _mid with the reference device 3, X _{0_b_mid} , Y _{0_b_mid} , Z _{0_b_mid} are tristimulus values of the image light corresponding to the inflection point B _mid. This is a measured value measured by the reference device 3. X _{m_r_mid} , Y _{m_r_mid} , and Z _{m_r_mid} are measured values obtained by measuring the tristimulus values of the image light corresponding to the inflection point R _mid with the tristimulus value direct reading type measuring instrument 2, X _{m_g_mid} , Y _{m_g_mid} , and Z _{m_g_mid} , X _{m_b_mid} , Y _{m_b_mid} , and Z _{m_b_mid} are measured values obtained by measuring the tristimulus values of the image light corresponding to the inflection point G _mid with the tristimulus value direct reading type measuring device 2, and the image light corresponding to the inflection point B _mid Is a measurement value obtained by measuring the tristimulus value by the tristimulus value direct reading type measuring instrument 2.

The second correction calculation unit 66 sets the points O, R _mid , G _mid , B _mid , R _max , G _max , and B _max measured by the calibration target measurement value acquisition unit 63 and the reference device measurement value acquisition unit 64. Based on the tristimulus values of the corresponding image light, the second correction matrix M _red for _red , the second correction matrix M _green for _green , and the second correction matrix M _blue for _blue are calculated by the following equations (3) to (5). To do.

In the above formulas (3) to (5), X _{0_black} , Y _{0_black} , and Z _{0_black} are measurement values obtained by measuring the tristimulus values of the image light corresponding to the black display point O with the reference device 3. X 0 — _r100 , Y 0 — _r100 , Z 0 — _r100 are measured values obtained by measuring the tristimulus value of the image light corresponding to the red maximum brightness point R _max with the reference device 3, and X 0 — _g100 , Y 0 — _g100 , Z 0 — _g100 are the maximum green brightness point measurement value measured by the reference instrument 3 tristimulus values of the image light corresponding to _{G max, X 0_b100, Y 0_b100} , Z 0_b100 the image light tristimulus values corresponding to the blue maximum brightness point _{B max} Is a measurement value measured by the reference device 3.
X _{m_black} , Y _{m_black} , and Z _{m_black} are measurement values obtained by measuring the tristimulus value of the image light corresponding to the black display point O by the tristimulus value direct reading type measuring instrument 2. X _{m_r100} , Y _{m_r100} , and Z _{m_r100} are measured values obtained by measuring the tristimulus values of the image light corresponding to the red maximum brightness point R _max with the tristimulus value direct reading type measuring instrument 2, X _{m_g100} , Y _{m_g100} , Z _{m_g100} the green maximum brightness point measurements tristimulus values of the image light measured by the tristimulus value direct reading instrument device 2 corresponding to _{G max, X m_b100, Y m_b100} , Z m_b100 a blue maximum brightness point B _This is a measurement value obtained by measuring the tristimulus value of the image light corresponding to _max with the tristimulus value direct reading type measuring instrument 2.

FIG. 11 is a diagram illustrating the relationship between the change curve of each color output from the projector and the correction matrix. As shown in FIG. 11, the straight line connecting the black display point O and each of the maximum brightness points R _max , G _max , B _max deviates greatly from the change curve, but the black display point O and the inflection points R _mid , G _The straight line connecting _mid and B _mid is less shifted from the change curve. Similarly, a straight line connecting the inflection points R _mid , G _mid , B _mid and the respective maximum brightness points R _max , G _max , B _max has a small deviation from the change curve. That is, the inflection point _{R mid,} using G _mid, first correction matrix _{M dark} the color corresponding to the black display point O side of the _{B mid} inflection point _{R mid,} G _mid, than _{B mid} By using each color second correction matrix M _red , M _green , M _blue for the color corresponding to each maximum brightness point R _max , G _max , B _max side, the tristimulus value direct reading type measuring instrument 2 It is possible to perform good correction with little error.

When the chromaticity of the light emitted from the projector 5 is measured by the calibrated tristimulus value direct-reading measuring instrument 2, the switching transmittance calculating unit 67 performs the first correction matrix M _dark and the second correction matrix M _red , A switching transmittance, which is a threshold value for determining whether to use M _green or M _blue , is calculated. The calculation of the switching transmittance is calculated based on the following equation (6).

As shown in the above equation (6), the switching transmittance calculating means 67 includes the tristimulus values at the red inflection point R _mid and the maximum brightness point R _max measured by the tristimulus value direct reading type measuring instrument 2. The switching transmittance T th — _r for the red liquid crystal panel 55R is calculated from the X value that is the stimulus value typified by the red component. Further, among the tristimulus values at the green inflection point G _mid and the maximum brightness point G _max measured by the tristimulus value direct-reading measuring instrument 2, the lightness and the Y value that is the representative stimulus value of green are used for green. calculating a switching transmittance _{T Th_g} to the liquid crystal panel 55G. Similarly, among the tristimulus values at the blue inflection point B _mid and the maximum brightness point B _max measured by the tristimulus value direct-reading-type measuring instrument 2, the Z value, which is a stimulus value typified by the blue component, The switching transmittance T th — _b for the blue liquid crystal panel 55B is calculated.

In addition, the first correction calculation unit 65, the second correction calculation unit 66, and the switching transmittance calculation unit 67 include a first correction matrix M _dark , a second correction matrix M _red , M _green , M _blue , The switching transmittances T th — _r , T th — _g , and T th — _b are _readable and stored in a storage unit 68 of the calibration control device 6 and a correction value storage unit 222 (described later) provided in the tristimulus value direct reading type measuring instrument 2.

[Configuration of tristimulus direct-reading measuring instrument]
Next, the configuration of the tristimulus value direct reading type measuring instrument 2 will be described.
As described above, the tristimulus value direct reading type measuring instrument 2 includes the tristimulus value direct reading type sensor 21 and the test control unit 22, and the test control unit 22 is measured by the tristimulus value direct read type sensor 21. The obtained chromaticity (tristimulus value XYZ) is input. As shown in FIG. 7, such a tristimulus value direct reading type measuring instrument 2 is connected to a projector 5A to be inspected, and outputs a predetermined test pattern image from the projector 5A and measures its chromaticity. In the present embodiment, an example in which the tristimulus value direct-reading type measuring instrument 2 is directly connected to the inspection target projector 5A is shown. However, the tristimulus value direct-reading measuring instrument 2 is connected to the projector 5A via, for example, a personal computer. It is good also as a structure etc. which control is implemented.

  As shown in FIG. 7, the inspection control unit 22 includes an inspection object control unit 221, a correction value storage unit 222, a measurement value acquisition unit 223, a transmittance calculation unit 224, a transmittance determination unit 225, And a measured value calculation unit 226 that also functions as one correction unit and a second correction unit.

  The inspection target control means 221 controls the projector 5A to be inspected. Specifically, the inspection target control unit 221 performs control to emit image light of a predetermined test pattern image from the projector 5A. In addition, the inspection target control unit 221 performs control to switch the driving voltage applied to the liquid crystal panel 55 of the projector 5A and to emit image light having different brightness from the projector 5A.

The correction value storage unit 222 stores the first correction matrix M _dark , the second correction matrix M _red , M _green , M _blue , and the switching transmittance T _{th_r} , T _{th_g} , T _{th_b} set by the calibration device 1 described above. Storage area. The data stored in the correction value storage unit 222 is used by the transmittance determination unit 225 and the measurement value calculation unit 226 described later.

  The measurement value acquisition means 223 controls the tristimulus value direct reading type sensor 21 of the tristimulus value direct reading type measuring instrument 2 to measure the chromaticity (tristimulus value XYZ) of the image light emitted from the projector 5. The tristimulus values XYZ input from the stimulus value direct reading type measuring instrument 2 are acquired.

The transmittance calculation unit 224 calculates the transmittance of each color light transmitted through the liquid crystal panel 55 based on the tristimulus values XYZ acquired by the measurement value acquisition unit 223. Specifically, the transmittance calculating means 224, on the basis of the following equation (7), calculates the transmittance _{T D_ri} for red component, the transmittance _{T D_gi} for the green component, the transmittance _{T D_bi} for blue component.

In the above (7), X _{D_r100} is a representative stimulus value of the red component of the tristimulus values at the time of measuring the image light corresponding to the red maximum brightness point R _max tristimulus value direct reading sensor 21, Y _{d_g100} are representative stimulus value of the green component of the tristimulus values when measured by the tristimulus value direct reading sensor 21 an image light corresponding to green maximum brightness point _{G max,} Z d_b100 a blue maximum brightness point B _This is the representative stimulus value of the blue component of the tristimulus value when image light corresponding to _max is measured by the tristimulus value direct reading sensor 21. X _{d_ri} , Y _{d_gi} , and Z _{d_bi} are tristimulus values XYZ when arbitrary test pattern image light output from the projector 5 _{</ b> A} is measured by the tristimulus value direct reading type sensor 21.

The transmittance determining unit 225 uses the transmittances T _{d_ri} , T _{d_gi} , T _{d_bi} calculated by the transmittance calculating unit 224 and the switching transmittances T _{th_r} , T _{th_g} , T _{th_b} stored in the correction value storage unit 222. Compare and judge the magnitude relationship. For example, when measuring the chromaticity for the red component, the transmittance determining unit 225 uses the transmittance T _{d_ri} calculated by the transmittance calculating unit 224 and the switching transmittance T _{th_r} read from the correction value storage unit 222. Make a comparison. Green component, and a similarly for the blue component, the magnitude relationship between the respective transmittances _{T D_gi} and switching transmittance _{T Th_g,} determines the size relationship between the transmittance _{T D_bi} and switching transmittance _{T th_b.}

The measurement value calculation unit 226 reads the first correction matrix M _dark , the second correction matrix M _red , M _green , and M _blue stored in the correction value storage unit 222, and the tristimulus values acquired by the measurement value acquisition unit 223. XYZ is corrected by the calculation shown in the following equation (8).

Here, Md is M _dark or M _red (M _green when measuring the green component and M _blue when measuring the blue component), and is set according to the determination result of the transmittance determining means 225. That is, the measurement value calculating unit 226, the transmission determining unit 225, the transmittance _{T d_ri} (the measurement of the green component _{T D_gi,} the measurement of the blue component _{T d_bi)} measurement of switching the transmittance _{T th_r} (green component when _{If T Th_g,} when measuring the blue component is determined _{T th_b)} less than, using the first correction matrix _{M dark.} On the other hand, the measurement value calculating unit 226, the transmittance _{T d_ri} (the measurement of the green component _{T D_gi,} the measurement of the blue component _{T d_bi)} switching the transmittance _{T th_r} (the measurement of the green component _{T Th_g,} blue component When it is determined that it is larger than T th — _b ), the second correction matrix M _red (M _green when measuring the green component and M _blue when measuring the blue component) is used.

  In addition, the examination control unit 22 may perform control such that the tristimulus values XYZ corrected by the measurement value calculation unit 226 are displayed on, for example, a display (not shown) or output from an output terminal to an external device.

[Operation of calibration device and tristimulus direct reading type measuring instrument]
Next, operations of the calibration apparatus and the tristimulus value direct reading type measuring instrument as described above will be described with reference to the drawings.

[Calibration equipment calibration operation]
The calibration processing operation of the tristimulus value direct reading type measuring instrument 2 in the calibration apparatus 1 will be described. FIG. 12 is a flowchart showing the calibration process of the tristimulus value direct reading type measuring instrument in the calibration apparatus.
In the calibration of the tristimulus value direct-reading type measuring instrument 2, the calibration device 1 first controls the projector 5 by the projector control means 62 to apply the minimum set voltage to the red liquid crystal panel 55R and to the green liquid crystal panel 55G. Then, a maximum set voltage is applied to the blue liquid crystal panel 55B, and red light corresponding to the maximum red brightness point _Rmax is emitted.
Then, the stage control means 61 controls the movement of the calibration stage 4 to move the tristimulus value direct reading type measuring instrument 2 to the front of the projector 5.
Thereafter, the calibration target measurement value acquisition unit 63 and the reference unit measurement value acquisition unit 64 convert the tristimulus value of the red light corresponding to the red maximum brightness point emitted from the projector 5 to the tristimulus value direct reading type measuring instrument 2. And the measurement is performed by the reference device 3, and the measured value is acquired (step S101).

After step S101, the projector control means maintains the applied voltage to the green liquid crystal panel 55G and the blue liquid crystal panel 55B as it is, and changes the applied voltage to the red liquid crystal panel 55R to an inflection setting voltage (for example, 3.0 V). And the red light corresponding to the inflection point R _mid is output. Then, the calibration target measurement value acquisition unit 63 and the reference unit measurement value acquisition unit 64 cause the tristimulus value direct reading type measuring instrument 2 and the reference unit 3 to measure the tristimulus value of the red light corresponding to the inflection point R _mid. Then, the measured value is acquired (step S102).

Thereafter, by similar processing, the projector control means 62 emits green light corresponding to the green maximum brightness point G _max from the projector 5, and the green maximum brightness point is detected by the tristimulus value direct reading type measuring instrument 2 and the reference unit 3. A tristimulus value of green light corresponding to G _max is acquired (step S103). Further, the projector control means 62 causes the projector 5 to emit green light corresponding to the inflection point G _mid , and the tristimulus value direct-reading measuring instrument 2 and the reference unit 3 cause green light three corresponding to the inflection point G _mid to be emitted. A stimulus value is acquired (step S104).
Similarly, the blue light, the projector control unit 62, the blue light corresponding to a blue maximum brightness point B _max is emitted from the projector 5, the tristimulus value direct reading-type instrument 2 and blue maximum brightness point by reference device 3 A blue light tristimulus value corresponding to B _max is acquired (step S105). Further, the projector control means 62 emits blue light corresponding to the inflection point B _mid from the projector 5, and the tristimulus value direct-reading measuring instrument 2 and the reference device 3 cause the three blue light corresponding to the inflection point B _mid. A stimulus value is acquired (step S106).

  Further, the projector control means 62 applies a maximum setting voltage to each liquid crystal panel 55 and causes the projector 5 to emit black light. Then, the calibration target measurement value acquisition unit 63 and the reference device measurement value acquisition unit 64 acquire the tristimulus value of light corresponding to the black display point O by the tristimulus value direct reading type measurement device 2 and the reference device 3 (step S107). ).

Thereafter, the first correction calculation means 65 calculates the first correction matrix M _dark based on the above-described equation (2) using the tristimulus values obtained in steps S102, S104, and S106. The second correction calculation unit 66 uses the tristimulus values obtained in steps S102 to S107, and based on the above-described equations (3) to (5), the second correction matrices M _red , M _green , M _Blue is calculated (step S108).
Further, the switching transmittance calculating unit 67 calculates the switching transmittances T _{th_r} , T _{th_g} , T _{th_b} based on the above-described equation (6) using the tristimulus values obtained in steps S101 to S106 (steps). S109).
Further, the first correction matrix M _dark , the second correction matrix M _red , M _green , M _blue , and the switching transmittance T _{th_r} , T _{th_g} , T _{th_b} calculated in step S108 and step S109 are tristimulus value direct reading type. It is outputted to and stored in the correction value storage means 222 in the inspection control unit 22 of the measuring instrument 2.
Thus, the setting of the correction value of the tristimulus value direct reading type measuring instrument 2, that is, the calibration process is completed.

[Chromaticity measurement processing using a tristimulus direct-reading measuring instrument]
Next, the measurement processing operation when measuring the chromaticity of the projector 5A to be inspected by the tristimulus value direct reading type measuring instrument 2 will be described. FIG. 13 is a flowchart showing chromaticity measurement processing in the tristimulus value direct reading type measuring instrument. FIG. 14 is a flowchart showing the red tristimulus value measurement process in the chromaticity measurement process of the tristimulus value direct reading measuring instrument.

In the measurement of the chromaticity (tristimulus value) of the projector 5A to be inspected by the tristimulus value direct-reading type measuring instrument 2, as shown in FIG. Step S202) and blue single color chromaticity measurement (step S203) are sequentially performed.
In the chromaticity measurement of each color, in order to perform the same processing, chromaticity measurement with respect to red light will be exemplified and described.

In the measurement of the chromaticity of red light, as shown in FIG. 14, the inspection control unit 22 of the tristimulus value direct-reading type measuring instrument 2 controls the projector 5A by the inspection object control means 221 to control the red maximum brightness point R _max. The red light corresponding to is output. That is, the inspection target control unit 221 applies the minimum set voltage (0.0 V) to the red liquid crystal panel 55R of the projector 5A and also sets the maximum set voltage (5.0 V) to the green liquid crystal panel 55G and the blue liquid crystal panel 55B. ) Is applied.
Then, the measurement value acquisition unit 223 controls the tristimulus value direct reading sensor 21 to measure the red light emitted from the projector 5A, and acquires the tristimulus values _{Xd_r100} , _{Yd_r100} , and _{Zd_r100} (step S211). ).

Next, the inspection target control unit 221 sets the drive voltage of the red liquid crystal panel 55R of the projector 5A to an arbitrary voltage value to be measured (step S212). Then, the measurement value acquisition unit 223 controls the tristimulus value direct-reading sensor 21 to acquire the red light tristimulus values X _{d_ri} , Y _{d_ri} , and Z _{d_ri} that are output at this time (step S 213).

Thereafter, the transmittance calculating unit 224 uses the tristimulus values X _{d_r100} and X _{d_ri} acquired in steps S211 and S213 to calculate the transmittance T _{d_ri} based on the above-described equation (7) (step S214). .

Then, the transmittance determination unit 225 recognizes the switching transmittance T _{th_r} stored in the correction value storage unit 222, and determines whether or not the transmittance T _{d_ri} calculated in step S214 is larger than the switching transmittance T _{th_r.} Is determined (step S215).
When it is determined in step S215 that the transmittance T _{d_ri} is larger than the switching transmittance T _{th_r} , the measurement value calculation unit 226 reads the second correction matrix M _red from the correction value storage unit 222 (step S216). Then, the measurement value calculation unit 226 calculates the tristimulus values X ′ _{d_ri} , Y ′ _{d_ri} , and Z ′ _{d_ri} corrected based on the above-described equation (8) using the second correction matrix M _red as the correction value Md. (Step S217).

On the other hand, when it is determined in step S215 that the transmittance T _{d_ri} is smaller than the switching transmittance T _{th_r} , the measurement value calculation unit 226 reads the first correction matrix M _dark from the correction value storage unit 222 (step S218). . Then, the measurement value calculation means 226 performs the process of step S217 using the first correction matrix M _dark as the correction value Md, that is, the tristimulus values X ′ _{d — ri} , Y corrected based on the equation (8). ' _{d_ri} , Z' _{d_ri} is calculated.

[Effects of calibration device and tristimulus direct reading type measuring instrument]
As described above, the tristimulus value direct reading type measuring instrument 2 of the above embodiment calculates the transmittance of the liquid crystal panel 55 of the projector 5, and when this transmittance is smaller than the switching transmittance, the inflection point R is calculated. _The tristimulus values output from the tristimulus value direct reading sensor 21 are corrected by the first correction matrix M _dark calculated from the tristimulus values of the image light corresponding to _mid , G _mid , and B _mid . When the transmittance is larger than the switching transmittance, calculation is performed based on the black display point O, the inflection points R _mid , G _mid , B _mid , and the maximum brightness points R _max , G _max , B _max of each color. The tristimulus values output from the tristimulus value direct reading sensor 21 are corrected by the second correction matrices M _red , M _green , and M _blue .
In general, if the change curve when the voltage applied to the liquid crystal panel corresponding to each color is changed linearly from the black display point O to the maximum brightness point of each color on the chromaticity diagram, in practice, Because of non-linear change, only the difference causes an error. Therefore, when the correction value is obtained only by the three maximum brightness points, the tristimulus value measured by the tristimulus value direct-reading type measuring instrument 2 does not match the value measured by the reference unit 3, and an error occurs. End up. On the other hand, as described above, the transmittance of the light transmitted through the liquid crystal panel 55 is calculated, and based on this transmittance, the first correction is made for dark color light when it is equal to or lower than a predetermined switching transmittance. By applying the matrix M _dark and applying the second correction matrices M _red , M _green , and M _blue to the bright color light that has a transmittance greater than the predetermined switching transmittance, the tristimulus value direct-reading sensor 21 The measured tristimulus value XYZ can be appropriately corrected to a value that approximates the tristimulus value XYZ measured by the reference device 3. Accordingly, the peak wavelength varies depending on the driving voltage applied to the liquid crystal panel 55 due to the optical rotatory dispersion characteristic, and when the driving voltage applied to the liquid crystal panel 55 is changed, the change curve of each color on the chromaticity diagram has a non-linear shape. Even in this case, accurate chromaticity can be measured by the tristimulus value direct reading type measuring instrument 2. Further, by using such a tristimulus value direct-reading measuring instrument 2, the chromaticity of the image light emitted from the projector 5 can be measured more quickly than when using, for example, a spectroscopic measuring instrument, It can be easily incorporated into a production line in a factory and the productivity can be improved.

Further, the transmittance determining means 225 has tristimulus values XZY at the inflection points R _mid , G _mid , B _mid of each color on the color coordinates, and tristimulus at the maximum brightness points R _max , G _max , B _max of each color. The switching transmittance, which is a ratio with the value XYZ, and the transmittance are compared. For this reason, the first correction matrix and the second correction matrix can be selectively used for bright color light and dark color light at the inflection point. That is, for the dark light, black display point O from each color inflection point _{R mid,} G _mid, change curve to _{B mid} the color each from black display point O inflection point _{R mid,} G _mid, until _{B mid} And the first correction matrix M _dark can be used to perform correction with less error. On the other hand, for bright color light, a change curve from each color inflection point R _mid , G _mid , B _mid to each color maximum brightness point R _max , G _max , B _max is represented by each color inflection point R _mid , G _mid. , B _mid to approximately the straight line connecting the maximum brightness points R _max , G _max , B _{max of} each color, so that the second correction matrix M _red , M _green , M _blue can perform correction with less error. .
Therefore, the tristimulus value measured by the tristimulus value direct reading type measuring instrument 2 can be corrected to a more appropriate value in accordance with the measurement value of the reference unit 3, and a measurement value with less error can be calculated. Can do.

In the calibration device 1 according to the above embodiment, the calibration target measurement value acquisition unit 63 and the reference unit measurement value acquisition unit 64 control the reference unit 3 and the tristimulus value direct-reading measurement unit 2 so that they are on the chromaticity diagram. The tristimulus values of the colored light corresponding to the black display point O, the color inflection points R _mid , G _mid , B _mid , and the color maximum brightness points R _max , G _max , B _max are measured. Based on these values, the first correction calculation means 65 and the second correction calculation means 66 then calculate the first correction matrix M _dark and the second correction matrix M _red , according to the expressions (2) to (5). M _green and M _blue are calculated.
Therefore, the first correction matrix M _dark , the second correction matrices M _red , M _green , and M _blue as described above can be easily and accurately calculated based on the actual measurement values. Therefore, by storing such a correction value in the tristimulus value direct reading type measuring instrument 2, the tristimulus value of each color light output from the projector 5A by the tristimulus value direct reading type measuring instrument 2 can be accurately measured. it can.

Further, the switching transmittance calculating means 67 of the calibration apparatus 1 calculates and corrects the switching transmittance based on the color inflection points R _mid , G _mid , B _mid and the color maximum brightness points R _max , G _max , B _max. The value is stored in the value storage unit 222. Accordingly, since an accurate switching transmittance is calculated at the time of calibration, when measuring the chromaticity of the projector 5A to be inspected by the tristimulus value direct reading type measuring instrument 2, it corresponds to each tristimulus value direct reading type measuring instrument 2. With the appropriate switching transmittance, the correction value Md can be selected, and an appropriate measurement value can be calculated.

In the calibration apparatus 1, when the tristimulus value direct reading type measuring instrument 2 and the reference unit 3 are used to measure the color light of the projector 5, the calibration stage 4 is moved under the control of the stage control means 61, and the tristimulus value direct reading type measurement is performed. The device 2 and the reference device 3 are moved to the front of the projector 5. For this reason, the measurement conditions can be made the same in the tristimulus value direct-reading measuring instrument 2 and the reference instrument 3, and the more accurate first correction matrix M _dark , second correction matrix M _red , M _green , and M _blue can be calculated. Can do.

[Other Embodiments]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, in the calibration device 1, when measuring the chromaticity of the image light corresponding to the inflection points R _mid , G _mid , and B _mid , the projector control unit 62 applies a preset driving voltage to each liquid crystal. Although control to apply to the panels 55R, 55G, and 55B is performed, the present invention is not limited to this. For example, the calibration apparatus 1 may include an input unit, and may be configured to input or select a driving voltage corresponding to the inflection point by an input operation of the input unit by the user. Further, the projector control means 62 gradually changes the voltage applied to each liquid crystal panel 55. Then, the reference device measurement value acquisition means generates a change curve of the chromaticity diagram as shown in FIGS. 2 to 5 based on the measurement value measured by the reference device 3, and the inflection points R _mid and G _mid. , B _mid may be obtained by calculation.

  Further, as described above, the tristimulus value direct reading type measuring instrument 2 has a configuration in which the tristimulus value direct reading type sensor 21 and the inspection control unit 22 are integrally formed. In addition, the control device including the inspection control unit 22 may be configured as a separate unit and connected to be communicable via a cable line or the like. In such a configuration, a general-purpose personal computer or the like can be used as the control device, and the configuration can be simplified.

  Furthermore, in the above-described embodiment, the projectors 5 and 5A including the transmissive liquid crystal panel 55 that performs light modulation when the light is dropped are exemplified as the reference display device and the inspection target display device. However, the present invention is not limited to this. For example, the present invention may be applied to a single-plate LCD projector, a projector using a reflective liquid crystal panel such as LCOS (Liquid Crystal On Silicon), a projector using DLP (Digital Light Processing), and the like.

  In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

It is a figure which shows the wavelength and the transmittance | permeability which permeate | transmit a liquid crystal panel. It is a chromaticity diagram which shows the change curve at the time of changing the brightness of each color light separately from a liquid crystal panel on a color coordinate. In FIG. 2, it is the enlarged view to which the red change curve was expanded. In FIG. 2, it is the enlarged view to which the green change curve was expanded. In FIG. 2, it is the enlarged view to which the blue change curve was expanded. It is a block diagram which shows the structure of the calibration apparatus which concerns on one embodiment of this invention. It is a block diagram which shows schematic structure of the tristimulus value direct reading type measuring device of the said embodiment. It is a block diagram which shows the structure of the tristimulus value direct reading type sensor in the tristimulus value direct reading type measuring device of the said embodiment. It is a block diagram which shows schematic structure of the optical system in a projector. It is a block diagram which shows schematic structure of the calibration control apparatus in the calibration apparatus of the said embodiment. It is a figure which shows the relationship between the change curve of each color output from the projector, and a correction matrix. It is a flowchart which shows the calibration process of the tristimulus value direct reading type measuring device in the calibration apparatus of the said embodiment. It is a flowchart which shows the chromaticity measurement process in the tristimulus value direct reading type measuring device of the said embodiment. It is a flowchart which shows the red tristimulus value measurement process in the chromaticity measurement process of the tristimulus value direct-reading measuring device of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Calibration apparatus, 2 ... Tristimulus value direct-reading type measuring device as chromaticity measuring device, 3 ... Reference device as reference chromaticity measuring means, 5 ... Projector as reference display device, 62 ... Brightness control means Projector control means 63 ... Calibration target measurement value acquisition means as measurement value recognition means, 64 ... Reference instrument measurement value acquisition means as measurement value recognition means, 65 ... First correction calculation means, 66 ... Second correction calculation means, 67 ... switching transmittance calculating means, 222 ... correction value storing means, 224 ... transmittance calculating means, 225 ... transmittance determining means, 226 ... measured value calculating means that also functions as a first correcting means and a second correcting means.

Claims (7)

Multiple color lights are modulated according to the image information, and each color light is changed from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. A chromaticity measuring device that measures the chromaticity of light output from a display device having a light modulation element that changes a predetermined inflection point of a change curve,
Color measuring means for receiving each color light output from the display device to be measured and measuring the chromaticity of the received color light;
A transmittance calculating means for calculating the transmittance of each color light transmitted through the light modulation element;
A first correction matrix based on chromaticity at the three inflection points corresponding to each color light, and each color light based on the chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point. Correction value storage means for storing three second correction matrices;
A transmittance judging means for comparing the transmittance with a predetermined threshold and judging the magnitude relationship;
A first correction that corrects the chromaticity of each color light measured by the color measuring means in the first correction matrix when the transmittance determining means determines that the transmittance is smaller than the threshold value. Means,
Second correction means for correcting the chromaticity of each color light measured by the color measurement means in the second correction matrix when the transmittance determination means determines that the transmittance is greater than the threshold value. And a chromaticity measuring device. The chromaticity measuring device according to claim 1,
The transmittance calculating means calculates a ratio of the chromaticity of light to be measured to the chromaticity at the maximum brightness point of each color as the transmittance,
The transmissivity judging means compares the transmissivity and the switched transmissivity with a threshold value of the transmissivity that is a ratio of the chromaticity at the inflection point to the chromaticity at the maximum brightness point of each color. A chromaticity measuring device. Multiple color lights are modulated according to the image information, and each color light is changed from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. A chromaticity measurement method for measuring the chromaticity of light output from a display device having a light modulation element whose change curve changes at a predetermined inflection point,
Receiving each color light output from the display device, measuring the chromaticity of this color light,
Calculate the transmittance of each color light transmitted through the light modulation element,
A first correction matrix based on the chromaticity at the three inflection points corresponding to each color light when the calculated transmittance is compared with a predetermined threshold and the transmittance is smaller than the threshold. Then, when the measured chromaticity is corrected and the transmittance is larger than the threshold, each color light based on the chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point is applied. A chromaticity measurement method characterized by correcting the measured chromaticity of each color light with three corresponding second correction matrices. Multiple color lights are modulated according to the image information, and each color light is changed from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. A calibration device that calibrates a chromaticity measurement device that measures the chromaticity of light output from a display device that includes a light modulation element whose change curve changes at a predetermined inflection point,
A reference display device that outputs each color light serving as a reference chromaticity;
Brightness control means for changing the brightness of light output from the reference display device from the minimum brightness point to the maximum brightness point along the change curve;
Reference chromaticity measuring means for measuring the reference chromaticity of each color light output from the reference display device;
Measured value recognition for recognizing measured values of chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point of each color light measured by the reference chromaticity measuring means and the chromaticity measuring device. Means,
First correction calculation means for calculating a first correction matrix for correcting measurement values measured by the chromaticity measuring device based on chromaticity measurement values at the three inflection points corresponding to each color light;
Measurement measured by the chromaticity measuring device corresponding to each color light based on the measured values of chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point corresponding to each color light Second correction calculation means for calculating a second correction matrix for correcting values;
A calibration apparatus characterized by comprising: The calibration device according to claim 4,
A switching transmittance calculating means for calculating a switching transmittance that is a ratio of the chromaticity measurement value at the inflection point to the chromaticity measurement value at the maximum brightness point measured by the chromaticity measurement device; Calibration device characterized by The calibration device according to claim 4 or 5, wherein
The chromaticity measuring device and the reference chromaticity measuring means are arranged in parallel in a direction substantially orthogonal to a main optical axis of light emitted from the reference display device,
A calibrating apparatus, wherein the chromaticity measuring apparatus and the reference chromaticity measuring means are each provided with a translation control means for translating in a direction substantially perpendicular to the main optical axis. Multiple color lights are modulated according to the image information, and each color light is changed from the minimum brightness point where the brightness is minimum to the maximum brightness point where the brightness is maximum. A calibration method for calibrating a chromaticity measuring device that measures the chromaticity of light output from a display device that includes a light modulation element whose change curve changes at a predetermined inflection point,
Each color light that becomes the reference chromaticity from the reference display device is output by changing the brightness from the minimum brightness point to the maximum brightness point along the change curve,
Each color light that becomes the reference chromaticity is measured by the chromaticity measuring device and the reference chromaticity measuring means,
Recognizing the measurement values of chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point of each color light measured by these chromaticity measurement devices and reference chromaticity measurement means,
Based on the measured values of chromaticity at the three inflection points corresponding to each color light, the first correction matrix is calculated,
A second correction matrix corresponding to each color light is calculated based on measured values of chromaticity at the minimum brightness point, the maximum brightness point, and the inflection point corresponding to each color light. Calibration method.

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