JP2002323376A - Color information measuring method, display color evaluation method, display color adjusting method, and manufacturing method of device using them and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display color information measuring method capable of performing easily highly accurate chromaticity measurement, and a device using the method. SOLUTION: When imaging with a camera 3, an image 10a of a color display pattern projected on a screen 2 with a projector 1, and detecting color information of a display color of a display device within an imaged display screen, a spectral distribution measuring device 4 is used jointly, to thereby improve the color information detection accuracy and detection efficiency. Thereby, the chromaticity detection accuracy can be improved, and the quality evaluation standard of a color display device such as a projector can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring color information of a display image, a method for evaluating a display color, a method for adjusting a display color, an apparatus using the same, and a method for manufacturing a projector. The present invention relates to a method of measuring color information of a display image, a method of evaluating a display color, a method of adjusting a display color, and a device using the same, which are suitable for evaluating a display image.

[0002]

2. Description of the Related Art Conventionally, there has been a strong demand for increasing the size of a display screen of a television receiver or a personal computer. One type of display device capable of meeting this demand is a projection type represented by a liquid crystal projector. There is an image display device. In recent years, the progress and improvement of projection-type image display devices (projectors) have been remarkable, and expectations for performance improvements have only increased.Therefore, when evaluating the performance and product inspection, evaluation and color evaluation of displayed color images are performed. Measurement has become an important issue.

For this reason, various colorimetric methods and evaluation methods have been proposed in the past.
Japanese Patent Application Publication No. 2800 discloses a method of imaging a light emitting surface of a display device using a camera (color video camera) and estimating chromaticity coordinates from image data.

According to the method described in this publication, R (Red: red), G (Green: green), B
Each color signal value of (Blue: blue) is associated with a tristimulus value of the calibration photoelectric colorimeter by a coefficient and an offset term, and this correspondence is used at each measurement.

Other conventional techniques include a method of measuring the four corners and five points at the center of the display surface using a colorimeter, and a method of measuring the center of each region by dividing the display surface into nine parts. These are obtained from the measured values of several points that limit the chromaticity of the display surface. In this case as well, a method of fixing the chromaticity meter for each measurement point and sequentially moving the chromaticity meter to each measurement point Methods are known.

[0006]

Among the above prior arts, first, according to the method described in the above publication, when the displayed spectral distributions of the three primary colors (three primary colors) of R, G, and B have individual differences, If a calibration coefficient of each color obtained in advance is used, an error becomes large, and there is a problem in measurement accuracy. Further, in the method of measuring the chromaticity of a limited point on the display surface using a colorimeter, color unevenness at a position that is not a measurement point is missed, which also has a problem in measurement accuracy.

Further, in the case of a method in which a chromaticity meter is fixed for each measurement point, there is a problem that a plurality of chromaticity meters are required and the cost is increased. When performing, there is a problem that the measurement time becomes longer due to the movement. The present invention has been made in view of the above-mentioned problems of the related art, and has been developed in consideration of a method for measuring color information of a display image, a method for evaluating a display color, a method for adjusting a display color, and a method for easily obtaining high-precision chromaticity measurement. An object of the present invention is to provide a device utilizing the same.

[0008]

The object of the present invention is to provide a color information measuring method for measuring color information of a display image projected by a display device, comprising: a means for capturing the display image to obtain image data; The color information of the display image is obtained based on the image data and the spectral distribution data using at least two types of means for measuring at least one of an image and the projection light of the display device to obtain spectral distribution data. Achieved as given.

At this time, at least two kinds of means are provided: a means for capturing the display image to obtain image data, and a means for measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value. The above object can also be achieved by using means to provide the color information of the display image based on the data obtained from the image data and the tristimulus values.

[0010] The present invention is also directed to a display color evaluation method for evaluating a display color of a display image projected by a display device, comprising: means for capturing the display image to obtain image data; Means for measuring at least one of the projection light of the device to obtain spectral distribution data, means for obtaining color information of the display image based on the image data and the spectral distribution data, and a display color based on the color information Using at least four types of means for determining the distribution of
The evaluation of the display color is achieved such that the evaluation is given based on the distribution of the display color.

At this time, a means for capturing the display image to obtain image data, a means for measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value, Evaluating the display color using at least four types of means for obtaining color information of the display image based on the data obtained from the tristimulus values, and obtaining the display color distribution based on the color information. However, the above-mentioned object can be achieved even if it is provided based on the distribution of the display colors.

Another object of the present invention is to provide a display color adjusting method for adjusting a display color of a display device based on a display color evaluation of a display image projected by the display device. Means for obtaining at least one of the display image and the projection light of the display device to obtain spectral distribution data, and obtaining color information of the display image based on the image data and the spectral distribution data. The display color evaluation is achieved based on the display color distribution by using at least four types of means for performing the display color distribution based on the color information.

At this time, a means for capturing the display image to obtain image data, a means for measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value, Means for obtaining color information of the display image based on data obtained from the tristimulus values, and means for obtaining a distribution of display colors based on the color information, using at least four types of means, wherein the display color evaluation is The above object can be achieved even when the display color is given based on the distribution of the display colors.

Next, an object of the present invention is to provide a color information measuring device for measuring color information of a display image projected by a display device, an image pickup means for picking up the display image and obtaining image data, A spectral distribution measuring unit that measures at least one of the projection light of the display device to obtain spectral distribution data, and an arithmetic processing unit that calculates color information of the display image based on the image data and the spectral distribution data. Is achieved.

At this time, an image pickup means for picking up the display image to obtain image data, and a tristimulus value calculating means for measuring at least one of the display image and the projection light of the display device to calculate a tristimulus value. The above object can also be achieved by configuring the image processing apparatus with an arithmetic processing unit that calculates color information of the display image based on the image data and data calculated from the tristimulus values.

Further, the object of the present invention is to provide a display color adjusting apparatus for adjusting a display color of the display device based on a display color evaluation of the display image projected by the display device, wherein the display image is captured by Imaging means for acquiring data, and spectral distribution measuring means for measuring at least one of the display image and the projection light of the display device to acquire spectral distribution data,
Arithmetic processing means for acquiring color information of the display image based on the image data and the spectral distribution data; obtaining a distribution of display colors based on the color information; and calculating the display color based on the distribution of display colors. This is achieved by including a display color evaluation unit to be evaluated and a control unit that adjusts the display color of the display device based on the evaluation result by the display color evaluation unit.

At this time, an image pickup means for picking up the display image to obtain image data, and a tristimulus value calculating means for measuring at least one of the display image and the projection light of the display device to calculate a tristimulus value. And an arithmetic processing unit for calculating color information of the display image based on the image data and the data obtained from the tristimulus values; and obtaining a distribution of display colors based on the color information. The above object is achieved even if the display color evaluation means for evaluating the display color based on the display color evaluation means and the control means for adjusting the display color of the display device based on the evaluation result by the display color evaluation means are realized. it can.

When the spectral distributions of R, G, and B of the three primary color images projected by the display device have individual differences, the problem that the error increases when the calibration coefficient of each color obtained in advance is used is solved. Therefore, in the present invention, a spectral distribution is acquired for each object using a spectral distribution measuring device.

If a spectral distribution is obtained for each object by using a spectral distribution measuring device, the spectral distribution for each object can be referred to, so that accurate color information can be detected. Further, in the method of measuring the chromaticity of a limited point on the display surface using a colorimeter or the like, color unevenness at a position that is not a measurement point is overlooked. Decided to detect.

In addition, it is costly to prepare a number of colorimeters corresponding to the number of measurement points, and if one colorimeter is sequentially moved to perform measurement, the movement will increase the measurement time. However, there is a problem that mass production is not possible and costs increase. Therefore, in order to solve this problem, an imaging system is used and the imaging field of view is set to be larger than the color information detection area.

If color information of the entire surface is detected by using the image pickup system, measurement omission is eliminated, so that a display device with better color quality can be provided. In addition, by making the imaging field of view of the imaging system larger than the display surface, the movement time can be eliminated, and the measurement time can be shortened. In some cases, there is no need to move, so that the complexity of positioning and measurement time are greatly reduced, mass production becomes possible, and cost can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In the following description, as an embodiment of the present invention, a case will be described in which the present invention is applied to color information measurement of a color display image projected by a projection type color display device such as a liquid crystal projector. It is needless to say that the present invention is not limited to a projection type color display device, but is applicable to any type of color display device.

<Embodiment 1> FIG. 1 shows an example of a system to which Embodiment 1 of the present invention is applied. Here, an object of color information detection and display color adjustment is a projector 1 and, thereby, a screen. 2 is a color display image projected on the second image.

And, as shown, this system is:
A camera 3 for capturing a display image 10a projected on the screen 2, a spectral distribution measuring device 4 for measuring a spectral distribution of the display image 10a, an imaging system control unit 5, a spectral distribution measuring device control unit 6, a signal for imaging data. It comprises an interface 7, a signal interface 8 for spectral distribution measurement data, and a computer control unit 9 for processing data from these to calculate and evaluate color information.

Although not shown, the spectral distribution measuring device control unit 6 may be included in the signal interface 7 in some cases. Here, first, the camera 3 constitutes an image pickup system of the display image 10a, and therefore has a function of separating the three primary color lights and picking up an image using an image pickup device such as a CCD sensor. For this reason, as the camera 3, a combination of a color camera or a monochrome camera and a bandpass filter, or a combination of a CCD element and a bandpass filter is used. These may further include an optical filter and an imaging lens.

At this time, the field of view taken by the camera 3 is set to have a size including an arbitrary area of the display image 10a to be detected. Camera 3 for the display surface of
By providing means for changing the relative position of, or by arranging a plurality of cameras 3, imaging of the entire display surface is performed.

FIGS. 2 to 4 show a case where the camera 3 is composed of a combination of a monochrome camera and a band-pass optical filter, and a case where the camera 3 is composed of a combination of a CCD element and a band-pass optical filter. Here, it is assumed that an optical filter constituting the imaging system includes a UVIR cut filter, an ND filter, and the like in addition to the bandpass optical filter. At this time, an interference filter, a color glass filter, a gelatin filter, a plastic filter, or the like can be used as the bandpass optical filter.
It corresponds to the wavelength region of the three primary colors of the projector 1.

First, FIG. 2 shows a case in which a lens group 12 composed of three types of RGB is associated with each bandpass optical filter 11, and a display image 10a is displayed on a photoelectric conversion surface of one image sensor 13.
Are imaged side by side so that each imaging region 14
This is an example in the case where the imaging field of view 10b is secured by making the imaging devices 16 to 16 independent. Next, FIG. 3 shows an example in which independent image sensors 17 to 19 are provided for each of the positions of the imaging regions 14 to 16 by the lens group 12 and the bandpass optical filters 11.

Here, the examples of FIGS. 2 and 3 show a case in which three types of RGB optical systems are made independent. FIG. 4 shows a case where one lens system 11 covers the imaging field of view 10b and the band-pass optical system is used. This is a case where the filters 11 are sequentially switched to form RGB images in a time-series manner.

In addition, although not shown, a single lens system, each band-pass optical filter, and a dichroic mirror are associated with the same imaging field of view 10b, and the respective imaging positions are respectively set in the area of the imaging element. Alternatively, a method of providing a single lens system or a method in which each bandpass optical filter and a dichroic mirror correspond to each other to form an image on a region having a display surface or the entire display surface on an image sensor of each sensor may be used.

Next, FIG. 5 shows the arrangement of the band-pass optical filter.
As shown in (a), (b), (c), and (d), several examples are conceivable, and any of them may be used. Here, when imaging is performed in time series as in the example shown in FIG. 4, the filter is switched by moving the holder 22 as indicated by an arrow. At this time, an auxiliary bandpass optical filter may be added irrespective of the dimensions of the imaging system and the arrangement of the optical filters. It is desirable to dispose a UVIR cut filter, an ND filter, and the like between the image sensor and the display image.

Returning to FIG. 1, next, the spectral distribution measuring device 4
It functions to measure the spectral distribution of a certain area of the display image 10a. For this reason, a polychromator, a spectrometer, a spectrometer, a spectrophotometer, a spectrophotometer, and the like are used as the spectral distribution measuring device 4. When a spectroscope is used, for example, the spectral distribution measuring device 4 includes a light-collecting optical system such as a lens and an optical fiber, and a photoelectric conversion element such as a diffraction grating and a diode array.

Then, the spectral distribution obtained from the condensing optical system is converted into an electric signal by a photoelectric conversion element, and color information is converted by a spectral distribution measuring device control unit 6 composed of a computer or an LSI chip. Perform the necessary arithmetic processing to calculate. At this time, an optical filter may be arranged between the spectral distribution measuring device and the display image 10a.

The computer control unit 9 includes a computer as the name implies, and the imaging system control unit 5 and the spectral distribution measuring device control unit 6
, The camera 3 and the spectral distribution measuring device 4, and as described above, processes the data to calculate or evaluate color information. Next, a chromaticity calculation method and an evaluation method of the display image 10a according to this embodiment will be described.

First, in the color system calculated according to JIS Z8729, the basis is the amount of the primary stimulus, and the tristimulus values indicating the amounts of the three primary stimuli are based on JIS Z8724. The product of the value of the spectral distribution of the sample light source obtained at a certain wavelength interval and the value of the color matching function of the XYZ color system is integrated in a certain wavelength range by a prescribed tristimulus value calculation method, and a constant is obtained. Given by multiplying.

Therefore, the tristimulus values at an arbitrary point on the display image are obtained by obtaining a spectral distribution at a constant wavelength interval, integrating the product of the spectral distribution at the wavelength λ and the color matching function in a certain wavelength range, and setting the coefficient to an appropriate value. Can be calculated. The color information must be able to be calculated based on the tristimulus values calculated as described above.
It can be easily calculated from the calculation method specified in JIS.

[0037] For example, the photometric quantity, can be calculated from the calculation method of the tristimulus value defined in JIS Z8724, the chromaticity coordinates (x, y) and (x _10, y ₁₀₎ is JIS Z8724
Can be calculated by the method of calculating the chromaticity coordinates specified in, and further, the coordinates (u ′,
v ′) and (u ₁₀ ′, v ₁₀ ′) can be calculated by the chromaticity coordinate calculation method specified in JIS Z8729.

The value defined in the XYZ color system is
The value defined in the L ^* a ^* b ^* color system and the value defined in the L ^* u ^* v ^* color system can be calculated according to JIS Z8701. . Hereinafter, these are collectively referred to as chromaticity coordinates for convenience.

Next, a method of calculating a spectral distribution according to this embodiment will be described. Therefore, for example, when there are three types of primary color light of the projector 1, if the spectral distributions of the monochromatic light at the wavelength λ are r (λ), g (λ), and b (λ),
The spectral distribution W (λ, λ) of the point (i, j) on the surface of the display image 10a
i, j) are spectral distributions r (λ), g (λ), b (λ) of each color.
And the product of coefficients Kn (i, j) corresponding to the spectral distribution of each color, so that the following equation (1) is obtained.

W (λ, i, j) = K0 (i, j) · r (λ) + K1 (i, j) · g (λ) + K2 (i, j) · b (λ)... (1) Here, the spectral distributions r (λ), g (λ), and b (λ) of each color are obtained by measuring the primary color light with the spectral distribution measuring device 4, respectively.
Assuming n = 0 to 2, the unknown number Kn (i, j) can be obtained by measuring the spectral distribution of three or more different colors obtained by mixing the three primary colors.

Similarly, when m types of primary color lights are used, the spectral distribution is measured by the spectral distribution measuring device 4 for the unknowns Kn (i, j) (n = 0 to m-1) for m or more different colors. I will be asked. On the other hand, the brightness of an image obtained by imaging the point (i, j) on the display image 10a is
This corresponds to the light measurement taking into account the spectral sensitivity of the imaging system including the optical filter in the spectral distribution of the point (i, j) on the surface and the offset and gain depending on the imaging system and the like.

Accordingly, the gradation value of the point (i, j) on the display image 10a surface obtained by the imaging system (camera 3) has the wavelength λ
In a certain wavelength range, the product of the spectral sensitivity of the imaging system including the optical filter and the spectral distribution of the point (i, j) on the display surface at the wavelength λ is integrated in a certain wavelength range, and the offset and gain depending on the imaging system are calculated. Given by taking into account. Next, since the spectral distribution of the point (i, j) on the display surface is given by the above equation (1), the point (i, j) on the display surface after the offset of the imaging system is considered. The gradation value can be represented by a linear combination of Kn (i, j) and its coefficient An.

Therefore, when the primary color light is m types, the point (i,
j), and when m or more types of gradation values are obtained, the value Kn (i, j) and the coefficient An can be obtained by measuring the spectral distribution at different points of m or more on the display surface. it can.

At this time, the spectral distribution of the spectral distribution non-measurement point may be obtained from the coefficient An and the gradation value of the point (i, j) on the entire display surface obtained by the imaging system. Thus, the spectral distribution of the point (i, j) on the entire display surface including the spectral distribution non-measurement point can be obtained.

Here, when the projector 1 has three types of primary color light, the camera 3 captures images of three different display colors obtained by mixing the three primary color lights.
When the imaging system (camera 3) is a color camera, at least the spectral distribution of any one point on the display surface may be measured.

On the other hand, in the case of a monochrome camera or an imaging system in which a CCD element and a bandpass optical filter are combined, 3
When the transmission wavelengths of each type of bandpass optical filter are separated, color mixing does not occur in imaging, so
What is necessary is just to measure the spectral distribution of any one point on the display surface.

However, even in this case, if the transmission wavelengths of the three types of band-pass optical filters are not completely separated, color mixing occurs. Therefore, it is necessary to measure at least three arbitrary spectral distributions on the display surface. is there. At this time, in consideration of brightness unevenness of the imaging system, chromatic aberration of the imaging system, and the like, correction of the spectral distribution and gradation value corresponding to these may be performed as necessary.

Next, the wavelength interval of the output measured value by the spectral distribution measuring device 4 and the calculation accuracy of the tristimulus value will be described.
Now, here, the output measured value by the spectral distribution measuring device 4 is:
For example, as shown in FIG. 6, assuming that there is a spectral distribution showing a steep change in a narrow wavelength range of 5 nm to 10 nm, in this case, as shown in FIG. A change point as indicated by 24 cannot be completely handled.

In this case, as shown in FIG.
There is a risk that it will be recognized as a distribution state different from the original distribution, and in this case, the distribution state based on it will be erroneous, and the accuracy will be reduced with tristimulus values obtained from this. Inevitable.

Therefore, if the spectral distribution is measured at a wavelength interval narrower than 5 nm, even a sharp change as shown in FIG. 6 can be sufficiently captured, and a more accurate tristimulus value can be obtained. Therefore, it is desirable that the wavelength interval of the output measured value by the spectral distribution measuring device 4 is narrower than 5 nm.

Here, if the wavelength interval is sufficiently narrower than 5 nm, for example, 2.4 nm, JIS
The value of the corresponding color matching function may be obtained by interpolation from the values of the color matching functions in Appendix 1 or 2 of Z8724, and the above-described tristimulus value may be calculated. Accordingly, the flow of the processing so far is summarized as shown in FIG.

That is, first, the projector 1
An adjustment pattern of three primary colors to be subjected to color information detection and display color adjustment is projected on the screen 2, and a display image 10 a is projected on the screen 2. Thereafter, the processing shown in FIG. 8 is executed by the computer control unit 9 to calculate the color information of the display image 10a. Note that FIG.
In this example, i = 4 is set, but this is an example.

Next, a method of evaluating a display color according to this embodiment will be described. In this embodiment, the chromaticity coordinates of an arbitrary point on the display surface detected by the above-described detection method are displayed on a chromaticity diagram, an area S having a radius R is set on the chromaticity diagram, and the detection is performed. The evaluation is performed in such a manner that the chromaticity coordinates of an arbitrary point on the display surface outside the area S is used as a criterion for the quality judgment. This evaluation is also executed by the computer control unit 9. You.

At this time, for example, a grid point is set, the distance between the chromaticity coordinates of the grid point and the chromaticity coordinates at the center of the area S is obtained, and the distance is compared with the radius R of the area S for evaluation. The Euclidean distance between two points or JIS Z8730 may be used for the chromaticity coordinates obtained at any two grid points.
May be used to calculate a color difference or the like, and to calculate statistics such as an average value, a maximum value, a minimum value, a variance, and a deviation of these values, thereby evaluating a display color.

In this case, the interval between the lattice points is arbitrary,
It is desirable to set at smaller intervals. For example, when the number of grid points is made to correspond to the number of pixels of the image sensor, if the number of elements per side of the two-dimensional imaging system is 1024, chromaticity coordinates of about 1,048,576 points can be set over the entire display surface. it can. Here, as the number of grid points having chromaticity coordinates increases, the evaluation accuracy improves, so that the density of the grid points is, of course, preferably higher.

More specifically, FIG. 9 shows an embodiment in which the number of lattice points is k, and points P1 to Pk (symbol P12
To Pk are not shown) indicate each grid point. As described above, when there are three types of primary color light of the projector 1,
The tristimulus value can be obtained by measuring the spectral distribution for three different display colors obtained by mixing the primary color lights. In this case, any point at which the spectral distribution of the display surface should be measured by the spectral distribution measuring device 4 is determined. Point P1 and the remaining points P2 to Pk
Is a point at which color information is calculated from the gradation value obtained by the imaging system (camera 3) and the spectral distribution of the point P1. At this time, at the above point, tristimulus values may be measured instead of the spectral distribution.

Here, for comparison, FIG. 10 shows that
As an example of a measurement point in the prior art, only nine discrete points P1 to P9 are provided as shown in the figure. Therefore, when compared with the above-described embodiment, the point P in FIG.
10 to Pk exist as arbitrary points which are not measured in FIG.

Next, FIG. 11 shows points C1 to C in FIG.
k (symbols C12 to Ck-2 are not shown and only dots are displayed)
FIG. 10 illustrates chromaticity coordinates of k lattice points P1 to Pk illustrated in FIG. 9. The chromaticity coordinates of each of the k lattice points P1 to Pk indicate a state in which the chromaticity coordinates are all included in the region S. Therefore, in this case, in the evaluation based on the radius R of the region S, the display is performed. This indicates that the color uniformity of the entire surface is ensured, and that a high quality display surface is provided.

On the other hand, as shown in FIG.
Exists in the area S, and points C10 to Ck (C12 to Ck-
If 2 is not shown and only a point is displayed), the color is not uniform on the entire display surface if the region exists outside the region S, which means that the display surface is of poor quality. However, even in this case, a high quality display surface can be provided by adjusting a point outside the region S so as to fall within the region S by the above-described adjustment method.

However, in the case of the prior art shown in FIG.
As shown in, even when all the points C1 to C9 corresponding to the chromaticity coordinates of the nine measurement points P1 to P9 are present in the region S, the chromaticity coordinates of the non-measurement points P10 to Pk are Corresponding C10 to Ck may exist outside the region S,
In this case, since the measurement values of the non-measurement points C10 to Ck are not known, it is not possible to make an adjustment so as to fall within the region S, and therefore, it is not possible to provide a high quality display surface.

Therefore, the method according to this embodiment, that is, the method of calculating the color information of the entire display surface from the spectral distribution of an arbitrary point and the gradation value of the image pickup system of the entire display surface, uses the discrete 9 Compared with the case where the chromaticity of only points is measured, it is possible to greatly improve the evaluation accuracy, and to provide a display surface with good quality.

Next, the relationship between the setting of the center coordinates and the radius R of the area S and the color temperature of the display surface will be described. Here, since the chromaticity of the display surface changes when the color temperature of the display surface is different, if the center coordinates and the radius R of the area S serving as the evaluation reference are set in consideration of the color temperature of the display surface, Higher accuracy evaluation is possible. For example, if the color temperature of the display surface is 6100
If K is set to 6950K, the chromaticity coordinates are
(u ', v') = (0.198,0.469),
Using this as a reference coordinate, the area S
Set.

Similarly, when the color temperature of the display surface is 8500K to 1
If it is set to 0250K, the chromaticity coordinates (u ′,
v ′) = (0.189, 0.446) is set as the center coordinate. If the area S is set to 6980K to 8100K, the chromaticity coordinates (u ′, v ′) = (0 ′) .194,0.4
An area S is set so that (59) is the center coordinate, and 470 is set.
If set to 0K-5350K, the chromaticity coordinates
The area S is set so that (u ′, v ′) = (0.209, 0.488) is the center coordinate.

Next, the setting of the radius R and the judgment of good or bad are as follows. Color temperature 6100K-6950
If it is set to K, (u ′, v ′) = (0.198,
0.469) is the center coordinate of the area S, then R =
If 0.03 is set, for example, (u ′, v ′) = (0.0.
229, 0.500), the display color represented by the chromaticity coordinates (u ′, v ′) = (0.209, 0.480) is judged as good.

When R = 0.01 is set,
The display color indicated by (u ′, v ′) = (0.209, 0.480) is determined to be negative, but the chromaticity coordinates (u ′, v ′) = (0.204,
The display color represented by 0.475) is judged as good. Further, R
= 0.005, (u ', v') = (0.20
The display color represented by chromaticity coordinates (u ′, v ′) = (0.202, 0.473) is judged as good, while the display color represented by (4, 0.475) is judged as not. .

The color temperatures 4700K to 5350K, 6
The same applies to the cases of 980K to 8100K and 8500K to 10250K, and the description is omitted.

Then, as described above, the smaller the radius R of the set area S, the stricter the evaluation criterion becomes. Of the chromaticity coordinates detected on the entire display surface, 1024 elements per side existing outside the area S In the case of using the two-dimensional imaging system, color information of 1048576 points can be obtained. Therefore, according to the present invention, it is possible to provide color information with a precision of about 116508 times per display surface as compared with the conventional nine-point measurement, but the smaller the color information, the more uniform and high quality the display surface. Means. At this time, the number of points at which the chromaticity coordinates are obtained is preferably as large as possible over the entire display surface. However, since it is actually finite, a good judgment is made.
For example, as in the following case, a method of setting and determining the ratio of objects existing outside the region S can be considered.

Here, when the proportion of the chromaticity coordinates on the display surface outside the area S is 0%, the judgment is good, but other than this, 1% or less, 3% or less, 5% or less, An arbitrary ratio, such as 10% or less, 15% or less, or 25% or less, may be set to make a good determination.

If the result of the above evaluation of the display color by the computer control section 9 is negative, that is, if the calculated color information is out of the specified value, it is necessary to further correct the color of the projector 1. A process of calculating the details of the adjustment instruction and outputting it in a predetermined data format is executed, and the adjustment necessary for the color correction is performed on the projector 1 in accordance with the content of the adjustment instruction.

The calculation of the content of the adjustment instruction at this time is performed in any process until the projector 1 is completed as a product, and the adjustment is performed according to the process to complete the product. Of course, if the result is a good judgment, the product is completed as it is as an adjusted product. Here, the data output as the content of the adjustment instruction may be taken out in any form such as a printed matter (barcode), an electronic recording medium, a magnetic recording medium, and is not particularly limited.

Next, an embodiment of the display color adjusting apparatus in the case where the color information calculated by the above-described color information detection is out of the specified value will be described with reference to FIG. This FIG.
Is a device that fetches data from the computer control unit 9 to calculate the content of the adjustment instruction and inputs the adjustment instruction content to the projector 1. The data communication unit 25 exchanges data with the computer control unit 9 in FIG. A processing unit 26 for calculating the amount of color adjustment of the display, a memory 27 for storing color information of the display color and adjustment instructions, an operation processing unit 28 for converting the amount of display color adjustment into the output format of the signal generator for the display color, Memory 2 for storing data converted to the output format of the color signal generator
9, and a data communication unit 30 for exchanging data with the projector 1.

The arithmetic processing section 26 calculates the color adjustment amount of the display color to be adjusted from the color information of the display color received via the data communication section 25 and the adjustment instruction, and stores it in the memory 27. The arithmetic processing unit 28 functions to convert the color adjustment amount stored in the memory 27 into a signal format required by the display color adjustment signal generation unit in the projector 1 and store the signal format in the memory 29. Therefore, depending on the configuration of the projector 1, the arithmetic processing unit 28 and the memory 29 may be omitted. Therefore, the projector 1 uses the color adjustment amount received via the data communication unit 30 to optimize display color control data or the like corresponding to the display position held therein, and to adjust the display color control data at each display position. Adjust the display color.

For this reason, the projector 1 to be adjusted
Is equipped with a data reading means such as a barcode reader, a memory chip, and a microcomputer for adjustment.The color information chromaticity of each display color, the judgment result, adjustment instructions, correction history and The correction contents and the like are stored, and the adjustment of the display color at each display position is provided in the manufacturing process.

At this time, the data reading means is provided corresponding to the case where the adjustment instruction content data is given by the above-mentioned printed matter (bar code), electronic recording medium, magnetic recording medium, or the like. When the adjustment instruction content data is taken in via the device, a means for communicating with the data communication unit 30 is provided.

As a result, according to the first embodiment, it is possible to obtain color information of points corresponding to the number of elements of the imaging system. For example, when a two-dimensional imaging system having 1024 elements per side is used. If there is, color information of 1048576 points can be obtained.

Therefore, according to the first embodiment, as compared with the nine-point measurement in the case of the conventional technique, about 116 per display surface is required.
Color information can be provided with 508 times higher accuracy. According to the first embodiment, the adjustment of the display color at each display position can be automatically obtained in the manufacturing process together with the detection of the color information of the projector 1.

<Embodiment 2> Next, FIG. 14 shows an example of a system to which Embodiment 2 of the present invention is applied.
This system differs from the system of the first embodiment shown in FIG. 1 only in the direction of the spectral distribution measuring device 4, and the other configuration is the same. That is, the spectral distribution measuring device 4 in the second embodiment has a function of inputting not the screen 2 but the projection light of the display pattern projected from the projector 1 and directly measuring the spectral distribution from the projection light.

In the configuration of the present embodiment, since the spectral distribution of the display pattern image emitted from the projector is directly measured, a higher amount of light is obtained than that of the projected image in which the amount of light is diffused by the screen and the amount of light is attenuated. Becomes possible.

The configuration of the imaging system (camera 3), the configuration of the spectral distribution measuring device 4, the method of calculating and evaluating the chromaticity of the display surface, the method of adjusting the display color, and the like are the same as those of the first embodiment described with reference to FIG. Although the description is omitted because it is the same, the flow up to color information calculation according to the second embodiment is as shown in FIG.

Therefore, according to the second embodiment as well, it is possible to obtain color information of points corresponding to the number of elements of the image pickup system. For example, when a two-dimensional image pickup system having 1024 elements per side is used, 1048576 points can be obtained. Color information can be obtained, and as a result, color information can be provided with a precision of about 116508 times per display surface as compared with the nine-point measurement in the case of the conventional technique. The point that the adjustment of the display color at each display position can be automatically obtained in the manufacturing process is also the same as the first embodiment.

However, in the case of the second embodiment, since the spectral distribution of the display pattern image projected from the projector 1 is directly measured, as a result of being diffused by the screen 2,
A larger amount of light is obtained than when measuring from the projected image 10a in which the amount of light is attenuated, so that a more accurate spectral distribution can be obtained.

<Embodiment 3> Next, Embodiment 3 of the present invention.
As an alternative, instead of calculating the chromaticity of the display surface in the first or second embodiment, the following chromaticity calculation may be performed. First, the projector 1 repeatedly projects a single-color display pattern in which three primary colors are mixed as a pattern of four or more colors, and obtains dark current of an imaging device, noise of an optical system, and the like from imaging data obtained by imaging each display surface. Are removed to obtain signal values Rci, Gci, Bci (i = 1, 2, 3, 4,...).

Here, the symbols Rc, Gc and Bc represent the camera 3
Corresponds to R, G, and B of camera signals when the color camera is a color camera, and corresponds to signal values of each separated color when a monochrome camera or a combination of a CCD element and a color separation unit such as a band-pass optical filter is used. On the other hand, the spectral distribution measuring device 4 measures one or more points on each display surface. At this time, the measurement wavelength range of the spectral distribution is desirably 380 nm to 780 nm.

Next, according to JIS Z8724, the tristimulus value is a product of the value of the spectral distribution of the sample light source obtained at a constant wavelength interval and the value of the color matching function of the XYZ color system. It is given by integrating over the wavelength range and multiplying by a constant. Therefore, the tristimulus values of the spectral distribution measurement points on the display surface are integrated with the product of the spectral intensity at the wavelength λ of the spectral distribution measured at a constant wavelength interval and the color matching function in a certain wavelength range, and the coefficient is appropriately determined. Determine and calculate.

First, the following equation (2) is set for the point on the display surface where the spectral distribution was measured, and the signal value Rci,
From Gci, Bci and X, Y, Z color systems, coefficients α ₁₁ , α
_12, ..., to calculate the α _33.

[0086]

(Equation 2) Here, in the case of four colors, the coefficients α ₁₁ , α ₁₂ , and α ₁₂ are obtained by subtracting the relational expression of (Equation 2) composed of each of the three colors and the relational expression of (Equation 2) composed of the remaining one color. …, Α ₃₃
Can be uniquely determined, so that the offset terms β ₁ ,..., Β ₃ are calculated from this.

In the case of five or more colors, the coefficients α ₁₁ , α ₁₂ ,..., Α ₃₃ and the offset term β
₁ ,..., Β ₃ are calculated. Next, the non-measured points of the spectral distribution, the calculated coefficient _{α 11, α 12, ...,} α 33 and offset term β _1, ..., β _3, signal value Rci, Gci, with BCI, (number 2 ) is calculated X _i, Y _i, Z _i from the equation.

As a result, tristimulus values of points corresponding to the number of elements of the imaging system are obtained, and color information can be calculated based on these tristimulus values. Here, the above details are the same as those described in the first embodiment,
The flow up to color information calculation at this time is as shown in FIGS. Therefore, also in the third embodiment, the method of evaluating the display surface, the method of adjusting the display color, and the like are the same as those of the first embodiment, and the operation and effect are the same, and thus the description is omitted.

<Embodiment 4> Further, Embodiment 4 of the present invention
As an alternative, instead of calculating the chromaticity of the display surface in the first or second embodiment, the following chromaticity calculation may be performed. First, a signal value obtained by repeatedly projecting four or more colors of a single-color display pattern in which three primary colors of the projector 1 are mixed, and removing dark current of an imaging device, noise of an optical system, and the like from imaging data obtained by imaging each display surface. Rci, Gci, Bci
(i = 1, 2, 3, 4,...).

In the case of a color camera, Rc, Gc, and Bc are signal values corresponding to the camera signals R, G, and B, respectively. Corresponds to the signal value of each separated color.

On the other hand, at least one point on each display surface is measured by a photoelectric colorimeter to obtain measured values x, y, and Y. And
From these measured values x, y, and Y, tristimulus values X, Y, and Z are obtained by using an equation described in JIS. Here, a point on the display surface measured by the photoelectric colorimeter is represented by Equation (2), and coefficients α ₁₁ , α ₁₂ , α ₁₂ , α ₁₂ , ..., to calculate the α _33.

In the case of four colors, the relational expression (Equation 2) consisting of each of the three colors and the relational expression (Equation 2) consisting of the remaining one color
By subtracting the relational expression, the coefficients α ₁₁ , α ₁₂ ,…,
α ₃₃ can be uniquely determined, and the offset terms β ₁ ,..., β ₃ can be calculated from this. In the case of five or more colors, the coefficients α ₁₁ , α _{12 ,.} And offset terms β ₁ ,..., Β ₃ may be calculated.

Next, regarding the non-measurement points in the photoelectric colorimeter,
Using the calculated coefficients α11, α12,..., Α33 and offset terms β1,..., Β3, and Rci, Gci, and Bci, Xi, Yi, and Zi are calculated according to Equation (2). As a result, tristimulus values of points corresponding to the number of elements of the imaging system are obtained, and color information can be calculated based on these tristimulus values.

Here, the above details are the same as those described in the first embodiment, and the flow up to color information calculation at this time is as shown in FIG. 18 and FIG. Therefore, also in the fourth embodiment, the method of evaluating the display surface, the method of adjusting the display color, and the like are the same as those of the first embodiment, and the operation and effect are the same.

Although the representative embodiment has been described above, the present invention can be carried out in the following modes in addition to this. A. At least one of the display patterns corresponding to the mixed four primary colors and the four different colors of the projector is repeatedly imaged, and the measurement of the spectral distribution or the tristimulus value is performed on at least one point of each of the imaged display patterns. A color information detection method characterized by performing the following.

B. The imaging is repeatedly performed for each display pattern corresponding to three different colors that are a mixture of the three primary colors of the display image, and the measurement of the spectral distribution is performed at least at one point of each of the captured display patterns and the three primary colors of the projector. And a color information detection method characterized in that the color information detection method is repeated. C. A color information detection method, wherein the color information includes information on light intensity and chromaticity coordinates.

D. A color information detection method, wherein in the imaging, a wavelength region of light to be imaged is divided into a plurality of wavelength ranges. E. FIG. A display color evaluation method, wherein the color information includes information on light intensity and chromaticity coordinates. F. A display color evaluation method, wherein the obtained information on the distribution of display colors is stored in a storage unit. G. FIG. A display color evaluation method, characterized in that information on a distribution of display colors acquired as described above is stored in association with the projector.

H. A display color evaluation method, comprising outputting the obtained information on the distribution of display colors to a monitor screen, a printer, or the like. I. A display color evaluation device further comprising a display unit for displaying a result evaluated by the display color evaluation unit. J. A display color evaluation apparatus further comprising an output unit for outputting a result evaluated by the display color evaluation unit to an external storage unit.

[0099]

According to the present invention, since the spectral distribution is measured, the chromaticity detection accuracy is improved, and the quality evaluation standard of the display device can be improved. According to the present invention,
Since color information is detected over the entire display surface, oversight of local color unevenness is reduced, and a display device with high color quality can be easily provided.

Further, according to the present invention, since the inspection time of the display device can be greatly reduced, mass production becomes possible, the cost of the display device can be sufficiently reduced, and the effect of process improvement can be obtained. Therefore, the number of steps in the adjustment process can be reduced, and in this regard, the cost of the display device can be sufficiently reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a system to which a first embodiment of a color information measurement method according to the present invention is applied.

FIG. 2 is a configuration diagram illustrating a first example of an imaging system according to an embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a second example of the imaging system according to the embodiment of the present invention.

FIG. 4 is a configuration diagram illustrating a third example of the imaging system according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of an arrangement of an optical filter according to the embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a relationship between wavelength and accuracy at the time of spectral distribution measurement according to the embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between wavelength and accuracy when measuring spectral distribution according to the embodiment of the present invention.

FIG. 8 is a flowchart illustrating an example of a series of processing up to color information calculation according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating an example of a chromaticity coordinate calculation position according to the first embodiment of the present invention.

FIG. 10 is an explanatory diagram showing an example of a chromaticity coordinate calculation position according to the related art.

FIG. 11 is an explanatory diagram illustrating an example of an evaluation criterion according to the first embodiment of the present invention.

FIG. 12 is an explanatory diagram showing another example of the evaluation criterion according to the first embodiment of the present invention.

FIG. 13 is a block diagram illustrating an example of an adjustment device according to the first embodiment of the present invention.

FIG. 14 is a block diagram showing an example of a system to which a second embodiment of the color information measuring method according to the present invention is applied.

FIG. 15 is a flowchart illustrating an example of a series of processing up to color information calculation according to the second embodiment of the present invention.

FIG. 16 is a flowchart showing an example of a series of processing up to color information calculation according to a third embodiment of the present invention.

FIG. 17 is a flowchart showing another example of a series of processing up to color information calculation according to the third embodiment of the present invention.

FIG. 18 is a flowchart illustrating an example of a series of processing up to color information calculation according to a fourth embodiment of the present invention.

FIG. 19 is a flowchart showing another example of a series of processing up to color information calculation according to the fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 projector 2 screen 3 camera (imaging system) 4 spectral distribution measuring device 5 imaging system control unit 6 spectral distribution measuring device control unit 7, 8 signal interface 9 computer control unit 10a display surface 10b imaging field of view 11 bandpass optical filter 12 lens ( Lens group) 13, 17 to 19 Image sensor group 14 to 16 Image forming position 22 Holder 23, 24 Change point 25, 30 Data communication unit 26, 29 Memory 27, 28 Arithmetic processing unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Mochizuki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in Hitachi, Ltd. Production Technology Research Laboratory (reference) 2G020 AA08 DA02 DA12 DA63 5C061 BB03 CC05 5C066 AA03 AA15 BA20 CA08 CA17 EA03 EA15 EA17 EB01 EC01 GA01 GA05 GA32 KA11 KE07 KM11 KM13 5C082 AA02 AA21 BA34 BA35 BC03 BC05 CA12 CB08 DA53 DA61 DA86 MM10

Claims (12)

[Claims] 1. A color information measuring method for measuring color information of a display image projected by a display device, comprising: means for capturing the display image to obtain image data;
Using at least two types of means for measuring at least one of the display image and the projection light of the display device to obtain spectral distribution data, the color information of the display image is converted to the image data and the spectral distribution data. A color information detection method characterized in that the color information is provided based on the color information. 2. A color information measuring method for measuring color information of a display image projected by a display device, comprising: means for capturing the display image to obtain image data;
Using at least two kinds of means of measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value, the color information of the display image is obtained from the image data and the tristimulus value. A color information detection method characterized in that the color information is provided based on obtained data. 3. A display color evaluation method for evaluating a display color of a display image projected by a display device, wherein: a means for capturing the display image to obtain image data;
A means for measuring at least one of the display image and the projection light of the display device to obtain spectral distribution data; a means for obtaining color information of the display image based on the image data and the spectral distribution data; A display color evaluation method, wherein at least four types of means for obtaining a display color distribution based on information are used, and the evaluation of the display color is given based on the distribution of the display colors. 4. A display color evaluation method for evaluating a display color of a display image projected by a display device, comprising: means for capturing the display image to obtain image data;
Means for measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value; means for obtaining color information of the display image based on the image data and data obtained from the tristimulus value A display which uses at least four kinds of means for obtaining a distribution of display colors based on the color information, and wherein the evaluation of the display color is given based on the distribution of the display colors. Color evaluation method. 5. A display color adjusting method for adjusting a display color of the display device based on a display color evaluation of a display image projected by the display device, wherein the display image is captured and image data is acquired. Means,
A means for measuring at least one of the display image and the projection light of the display device to obtain spectral distribution data; a means for obtaining color information of the display image based on the image data and the spectral distribution data; A display color adjustment method, wherein the display color evaluation is given based on the display color distribution using at least four types of means for obtaining a display color distribution based on information. 6. A display color adjusting method for adjusting a display color of the display device based on a display color evaluation of a display image projected by the display device, wherein the display image is captured and image data is acquired. Means,
Means for measuring at least one of the display image and the projection light of the display device to obtain a tristimulus value; means for obtaining color information of the display image based on the image data and data obtained from the tristimulus value A display color evaluation means for obtaining a display color distribution based on the color information, wherein the display color evaluation is given based on the display color distribution. Adjustment method. 7. A color information measuring device for measuring color information of a display image projected by a display device, wherein: an imaging means for capturing the display image to obtain image data; and projecting the display image and the display device. It is configured by spectral distribution measuring means for measuring at least one of light to obtain spectral distribution data, and arithmetic processing means for calculating color information of the display image based on the image data and the spectral distribution data. A color information detecting device characterized by the above-mentioned. 8. A color information measuring device for measuring color information of a display image projected by a display device, wherein: an imaging means for capturing the display image to obtain image data; and projecting the display image and the display device. Tristimulus value calculating means for calculating tristimulus values by measuring at least one of light, and arithmetic processing means for calculating color information of the display image based on the image data and data calculated from the tristimulus values. A color information detection device, comprising: 9. A display color adjustment device for adjusting a display color of the display device based on a display color evaluation of a display image projected by the display device, wherein the display image is imaged and image data is acquired. Imaging means; spectral distribution measuring means for measuring at least one of the display image and the projection light of the display device to obtain spectral distribution data; color information of the display image based on the image data and the spectral distribution data Calculation processing means for obtaining a display color distribution based on the color information, and a display color evaluation means for evaluating the display color based on the display color distribution. Control means for adjusting the display color of the display device based on the display device. 10. A display color adjustment device for adjusting a display color of the display device based on a display color evaluation of a display image projected by the display device, wherein the display image is captured and image data is acquired. An imaging unit, a tristimulus value calculating unit that measures at least one of the display image and the projection light of the display device, and calculates a tristimulus value, based on the image data and data obtained from the tristimulus value. Arithmetic processing means for calculating color information of a display image; display color evaluation means for obtaining a display color distribution based on the color information; and evaluating the display color based on the display color distribution; Control means for adjusting the display color of the display device based on the evaluation result by the means. 11. A method of manufacturing a projector for displaying a color image, comprising: obtaining an image data of the display pattern by imaging a display pattern; measuring a spectral distribution of the display pattern; Obtaining color information of the display pattern based on image data and data obtained from the measured spectral distribution, evaluating a display color based on the obtained color information, and processing the projector according to the evaluation result A method for manufacturing a projector, comprising: selecting the next step to be performed. 12. A method of manufacturing a projector that displays a color image, comprising: obtaining a display pattern image data by imaging a display pattern; measuring a spectral distribution of the display pattern; Obtaining color information of the display pattern based on image data and data obtained from the measured spectral distribution, evaluating a display color based on the obtained color information, and processing the projector according to the evaluation result Selecting the next step to be performed, and sending the data obtained by evaluating the display color to the next step together with the projector.