JPH0449835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to the adjustment of color television receivers;
The present invention relates to a method and apparatus for testing color saturation of color television receivers suitable for quality control and the like.

[Background of the invention]

Conventionally, the manufacturing process for color television receivers includes an adjustment process and a quality control process as final processes, in which final adjustments and performance inspections are performed before the finished color television receiver is shipped. .

It is also the process that is least automated in terms of manufacturing process automation.

These final adjustments and performance tests are performed by actually operating the color television receiver, but some adjustments and performance tests include checking the saturation (color saturation) of the screen displayed on the color television receiver. color intensity)
It also includes adjustments and inspections made by inspecting.

By the way, in the chroma test of a projected image, a specific color screen such as a reference white or the primary colors of red, green, and blue is projected on the color television receiver to be tested, and a skilled worker visually evaluates the visual sensation. Conventionally, the common method was to do this by:

That is, the color saturation of the respective projection screens of the standard color television receiver and the color television receiver to be tested is visually compared. It is designed to determine whether the inspection color television receiver requires adjustment and whether its performance is good or bad.

However, in this type of visual saturation test, there are variations in the judgment criteria depending on the level of skill of the worker, individual differences, severity of fatigue, physical condition, etc., and objective tests based on fixed judgment criteria are difficult. It is difficult to do this, and it is very difficult to ensure the quality of color television receivers on the market.

Therefore, as a method to quantitatively measure the saturation of a color television receiver, the luminescence intensity of each of the three primary colors (red, green, and blue) of the color television receiver is measured individually. Methods for determining the saturation of additive colors have been proposed and reported.

As one method, as shown in Japanese Patent Publication No. 54-20816, first, a standard white image is projected onto the color television receiver to be inspected, and electricity is generated corresponding to each primary color light from this white screen. Obtain the signal, adjust the electronic circuit so that the zero center indicator indicates the zero center for each electrical signal, and then project the desired saturation on the color television receiver signal to be tested, There is a method of detecting the amount of deflection of a zero center indicator with respect to the primary color light from this screen and measuring the difference in saturation between a white screen and a screen with a desired saturation.

According to this method, the difference between a standard white screen and a desired screen is expressed by the deflection of a zero center indicator, and objective inspection of color television receivers is performed based on certain criteria. However, when testing the saturation of different types of color television receivers with different luminescent characteristics of the phosphors for each primary color, it is necessary to test the white screen each time the color television receiver changes. In order for the zero center indicator to indicate the zero center, it is essential to adjust the electronic circuit, which not only requires manpower but also increases the time required for inspection.

Another method to quantitatively measure saturation is
There is a method shown in Jiko No. 51-39055.

In this method, each photoelectric conversion device is irradiated with each primary color light from the screen projected on the color television receiver to be inspected, and an electrical signal representing the intensity of each primary color light from each photoelectric conversion device is obtained. This method measures the luminous intensity of each primary color and phosphor of a color television receiver to be inspected by arithmetic processing of electrical signals.

Arithmetic processing of electrical signals is performed using a calculation circuit section whose circuit configuration is determined by the spectral energy distribution characteristics of each additive primary color emitted by the color television receiver under test and the spectral sensitivity characteristics of the photoelectric conversion device. For this reason, in order to test the saturation of different types of color television receivers, each of which has different light emitting characteristics for each primary color phosphor, a calculation circuit section with a circuit configuration corresponding to each type is prepared. Then, the calculation circuit used is changed depending on the type of color television receiver to be inspected.

According to this method, it is no longer necessary to adjust the saturation test device every time the type of color television receiver to be tested differs, but it takes time and effort to replace the calculation circuit section.
This will require more manpower, increase the number of work steps, and reduce the inspection efficiency.

Furthermore, since a calculation circuit unit is required for each type of color television receiver to be inspected, the number of parts also increases, and there is a large possibility that errors in selection of the calculation circuit unit to be used will occur.

Furthermore, the saturation test is influenced by the characteristics of the photoelectric conversion device and the luminescent characteristics of the phosphor, and is also influenced by the consistency between these characteristics and the circuit configuration of the calculation circuit section. , inspection accuracy cannot be sufficiently increased.

Furthermore, as another method for quantitatively measuring saturation, it is assumed that the phosphors of each primary color in a color television receiver have specific emission characteristics (spectral distribution characteristics), and A method for measuring the luminescence intensity of a phosphor has also been proposed, but if the luminescence characteristics of the color television receiver under test differ from the assumed luminescence characteristics, large errors will occur in the measurement results, leading to unreliable results. will be significantly lower.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art,
It is possible to automatically measure the saturation (color density) of the projected screen of the color television receiver being inspected, and objective measurement results can be obtained. It is an object of the present invention to provide a method and apparatus for testing the saturation of a color television receiver, which can be used commonly for all types of television receivers and can be tested quickly and easily.

[Summary of the invention]

In order to achieve this object, the present invention selectively projects and images a standard white screen and a screen with a desired saturation on a color television receiver to be inspected. The intensity ratio of each primary color signal with respect to the screen is calculated to determine the emission intensity ratio of each primary color light of these screens, and the chroma of the screen having the desired chroma is detected based on the emission intensity ratio. The points are distinctive.

[Embodiments of the invention]

First, the colors displayed on the screen of a color television receiver will be explained.

As we all know, colors have hue and saturation (color intensity).
There are three attributes: brightness and brightness, and the relationship between them is expressed three-dimensionally as shown in FIG. In other words, in the same figure, considering a conical shape, brightness (i.e., luminance) is taken in the direction along the central axis, hue is taken in the rotational direction about the central axis, and color is taken in the radial direction from the central axis. You can take degrees. Then, if we take the change in brightness of an achromatic color from white to black on the central axis, the radius from this central axis (in this case, called the achromatic axis) also represents the saturation, and the cone The maximum saturation is at the radius of the curved surface of the shape. Hue is expressed in order of wavelength by a ring around the achromatic axis to the left, and this ring is called the hue ring. The lower the brightness of a color, the closer it is to the apex of the cone, and the narrower the range of saturation.

Further, the relationship between hue and saturation in an arbitrary plane perpendicular to the conical shape and the achromatic axis in FIG. 1 can be represented by the chromaticity diagram shown in FIG. 2a. In the figure, hues are arranged in the order of wavelengths in a counterclockwise direction on a horse-shaped curve centered on white, and the length from white in the direction of this curve also represents saturation.

In a color television receiver, phosphors of the three primary colors red R, green G, and blue B coated on the fluorescent surface of the picture tube emit light, and the emitted three primary color lights are appropriately superimposed. Although a color image is being reproduced, the range of chromaticity that can be reproduced by a color television receiver is within the triangle formed by connecting the points of the three primary colors R, G, and B in Figure 2a. be. Figure 2b compares the color reproduction range of a color television receiver with the color reproduction range of color film and color printed matter.
It can be seen that the color reproduction range of color television receivers is quite wide.

By the way, in order for a color television receiver to display a color image, a color video signal is supplied. FIG. 3 is a waveform diagram showing a color video signal over one horizontal period, where E _N is the color video signal;
E _Y is a luminance signal, C is a carrier color signal, HS is a horizontal synchronization signal, B _S is a color burst signal, and H is a 1
Indicates a horizontal period.

The human eye perceives brightness at a ratio of 0.3:0.59:0.11 to the three primary colors R, G, and B of a color television receiver.
Assuming that the primary color signals for each are E _R , E _G , and E _B , the luminance signal E _Y is expressed by the following equation.

E _Y =0.3・E _R −0.59・E _G・0.11・E _B ……(1) On the other hand, the carrier color signal C is composed of two color difference signals (E _R
−E _Y ) and (E _B −E _Y ), the same frequency (3.58MHz)
The subcarriers whose phases differ by 90° are balancedly modulated and mixed.The subcarriers balancedly modulated with each color difference signal are expressed as follows. Here, t is time and f _S is the subcarrier frequency.
Note that since the luminance signal E _Y originally contains R, G, and B components, the color difference signals (E _R −E _Y ), (E _B
−E _Y ), it is possible to form a color difference signal ( _EG −E _Y ) from these and the luminance signal E _Y , and therefore, a color difference signal (E _{G −E} E _Y ) need not be included.

By the way, when transmitting the color video signal _EN , the frequency band is limited to approximately 4 MHz, which is the same as the black-and-white video signal, in order to prevent the frequency band from expanding unduly. For compatibility with television receivers, the frequency band of the luminance signal E _Y in the color video signal is set to approximately 4MHz, similar to the black and white video signal. , for this purpose, two color difference signals (E _R −
E _Y ) and (E _B −E _Y ) are superimposed on the luminance signal E _Y and transmitted simultaneously, but their frequency band is 0.5MHz.
is set within the frequency band of the luminance signal E _Y ,
Their amplitude is also 1/1 in the color difference signal (E _R −E _Y ).
1.14 times, and 1/1 for the color difference signal (E _B −E _Y )
It is limited to 2.03 times to prevent overmodulation. Therefore, the color video signal E _N is expressed as follows from equations (1) and (2).

E _N = E _Y + (E _R −E _Y )/1.14・cos(2π・f _S・t) + (E _B
−E _Y )/2.03・sin(2π・f _S・t)……(3) The color video signal E _N expressed by equation (3) is converted into primary color signals E _R , E _G , E in the color television receiver. _B
and stimulate the corresponding primary color phosphors in the color picture tube. Therefore, each primary color phosphor emits primary color light at an emission intensity depending on the intensity of the primary color signal. The primary color lights emitted from each primary color phosphor are additively mixed, and as a result, a color screen with a hue and saturation corresponding to the color video signal E _N expressed by equation (3) is displayed on a color television receiver. It is.

The hue and saturation of the color screen thus projected can also be expressed by the ratio of the primary color signals _ER , _EG , and _EB .

First, hue will be explained. Hue is generally expressed using the phase difference between the carrier color signal C and the color burst signal B _S shown in FIG. 3. In other _words , _the reference signal ( _B
−Y axis), and the hue is expressed by the phase angle Θ of the carrier color signal with respect to the hue signal (E _B −E _Y ), and the hue of the color video signal E _N expressed by equation (3) is as follows. It is expressed as follows.

Θ＝tan ^-1 {(E _R −E _Y /1.14/(E _B −E _Y )/2.03}……(
4) Figure 4 shows the phase angle and amplitude of the three primary colors R, G, and B and their complementary colors (magenta ( _MG ), cyan ( _CY ), and yellow ( _YL )). It is a vector diagram. Note that it is a color burst signal.

Also, the length of the vector in Fig. 4 is
The amplitude of the carrier color signal C shown in the figure represents its saturation, and the larger the amplitude of the carrier color signal C, the higher the saturation. The saturation of the color video signal E _N expressed by equation (3) can be expressed by the amplitude e given by the following equation.

In FIG. 4, for example, the hue of the blue B color video signal is Θ=
It can be expressed as 347°, and the saturation at that time is e
It can be expressed as =0.44.

The present invention measures saturation based on equation (5), and embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 is a block diagram showing an embodiment of the present invention, in which 1 indicates a color television receiver to be inspected;
2 is an optical filter, 3 is a photoelectric conversion element, 4 is an amplifier, 5 is a storage device, 6 is a signal strength calculation device, 7 is a saturation calculation device, 8 is a hue calculation device, 9 is a saturation display device, and 10 is a hue 11 is a filter conversion device, 12 is a color pattern generation device, and 13 is a synchronization signal generation device.

In the figure, an optical filter 2 is converted by a filter conversion device 11 into red, green, and blue color filters. The photoelectric conversion element 3 is here a black-and-white television camera, and images the projected screen of the color television receiver 1 to be inspected via the optical filter 2. The color pattern generator 12 is
A color video signal for projecting a desired color pattern on the screen of the color television receiver 1 to be inspected is generated, and synchronized with the photoelectric conversion element 3 by a synchronization signal generator.

Next, the operation of this embodiment will be explained.
First, the signal obtained from the photoelectric conversion element 3 will be explained.

Now, let R(λ) be the emission characteristic of the red phosphor in the picture tube of the color television receiver to be inspected, G(λ) be the emission characteristic of the green phosphor, and B(λ) be the emission characteristic of the blue phosphor. ), these emission characteristics are the sixth
As shown in Figure a, each of the wavelengths has a widened base centered on red, green, and blue wavelengths.

Therefore, as shown in FIG. 6b, the optical filter 2 has transmittance characteristics of F _R (λ) and F _G
(λ), F _B (λ), a red filter, a green filter, and a blue filter are used, and the photoelectric conversion element 3
Assuming that the optical filter 2 has the spectral sensitivity characteristic S(λ) shown in FIG. b, the respective outputs of the photoelectric conversion element 3 when the optical filter 2 is a red filter, a green filter, and a blue filter The signals V _R , V _G , and V _B are expressed as follows.

V _R =∫ ^∞ ₀ 0.3・E _R・R(λ)・F _R (λ)・S(λ)・d
λ V _R =∫ ^∞ ₀ 0.3・E _R・R(λ)・F _R (λ)・S(λ)・d
λ V _G =∫ ^∞ ₀ 0.59・E _G・G(λ)・F _G (λ)・S(λ)・d
λ V _R =∫ ^∞ ₀ 0.3・E _R・R(λ)・F _R (λ)・S(λ)・d
λ V _G =∫ ^∞ ₀ 0.59・E _G・G(λ)・F _G (λ)・S(λ)・d
λ V _B =∫ ^∞ ₀ 0.11・E _B・B(λ)・F _B (λ)・S(λ)・d
λ...(6) (However, E _R , E _G , and E _B are primary color signals obtained in the color television receiver 1 to be inspected to cause each primary color phosphor to emit light.) Note that the optical filter When 2 is a red filter, as is clear from FIG. 6a, part of the light emitted by the green and blue phosphors of the color television receiver 1 to be tested passes through the red filter. Enters the photoelectric conversion element 3, and the signal component resulting from this is expressed by formula (6)
However, by appropriately setting the transmittance characteristics of the red filter, this signal component can be made sufficiently small, and the output signal V _R can be approximated as shown in equation (6 ₎ . There is no problem.
Similarly, by appropriately setting the transmittance characteristics of the green filter and the blue filter, the amount of light emitted by the red phosphor and the blue phosphor transmitted through the green filter, and the amount of light emitted by the red phosphor and the green phosphor The amount of transmitted light through the blue filter can be made sufficiently small, and the output signals V _G and V _B can be approximated as shown in equation (6).

In equation (6), E _R , E _G , and E _B are independent of the wavelength λ of light, so X=∫ ^∞ ₀ R(λ)・F _R (λ)・S(λ)・dλ Y=∫ ^∞ ₀ G(λ)・F _G (λ)・S(λ)・dλ Z=∫ ^∞ ₀ B(λ)・F _B (λ)・S(λ)・dλ ……(7) Then, the formula (6) becomes as follows.

V _R =0.3・E _R・X V _G =0.59・E _G・Y V _B =0.11・E _B・Z ...(8) The optical filter 2 in Fig. 1 is a red filter, a green filter, and a blue filter. The output signals V _R , V _G , V _B of the photoelectric conversion element 3 obtained at this time are expressed by equation (8). Therefore, from these output signals (hereinafter referred to as color signals) V _R , V _G , and V _B , equation (8) is obtained.
By calculating the primary color signals E _R , E _G , and E _B based on the equations (1) and (4), the phase angle Θ can be obtained and the hue can be determined, and the equation ( 1), (5), the amplitude e
You can find out the saturation by calculating. but,
The constants X, Y, and Z in equation (8) are the light emission characteristics of each primary color phosphor in the picture tube of the color television receiver 1 to be inspected, and the transmittance characteristics of the optical filter 2, as shown in equation (7). , are constants determined by the spectral sensitivity characteristics of the photoelectric conversion element 3, etc., and it is very difficult to accurately determine these constants, and they are also prone to errors.

By the way, color television receiver 1 to be inspected
When a white image is projected on the screen, the primary color signal at this time is
The intensities of E _R , E _G , and E _B are equal to each other. Therefore, in this case, if E _R = E _G = E _B = E, the color signal W _R of the photoelectric conversion element 3 when the optical filter is a red filter, a green filter, or a blue filter,
W _G and W _B are expressed as follows from equation (8).

W _R =0.3・E・X W _G =0.59・E・X W _B =0.11・E・X ...(9) Therefore, from equation (8) and equation (9), the following relational expression can be obtained. .

E _R ／E=V _R ／W _R E _G ／E=V _G ／W _G E _B ／E=V _B ／W _B ......(10) This equation (10) can be used to calculate any hue for each primary color light. The intensity ratio of each color signal from the photoelectric conversion element 3 in the chroma screen and the white screen similarly corresponds to the intensity ratio of each primary color signal.

Here, the characteristic of a white screen is that the amplitude of the carrier color signal is 0 even if the color intensity control is turned.
Also, even if you turn the color tone volume, the value is 0.

Therefore, from equation (10), the primary color signal intensities E _R , E _R ,
By finding E _B and substituting it into equations (1) and (4), we obtain that each phase Θ,
That is, the hue is expressed as follows.

Θ＝tan ^-1 {(0.7V _R W _R −0.59V _G /W _G −0.11V _B
／W _B )／1.14／(−0.3V _R W _R −0.59V _G ／W _G −0.89V _B ／W _B
)/2.03}...(11) Similarly, from equations (1) and (4), the amplitude e, that is, the saturation, is expressed as follows.

Here, if e/E _Y is calculated, the unknown E on the right side of equation (12) can be eliminated, and e/E _Y becomes V _R /W _R , V _G /W as shown in the time formula. It is a function only of _G and V _B /W _B.

e/E _Y =
1/0.3V _R /W _R +0.59V _G /W _G +0.11V _B /W _B × From these equations (11) and (12), the hue and saturation can be determined from the color signal obtained from the color television receiver 1 to be tested. In this case, the picture tube of the color television receiver 1 to be tested It is not related to the emission characteristics of each primary color phosphor, the transmittance characteristics of the optical filter 2, and the spectral sensitivity characteristics of the photoelectric conversion element 3.

Now, in FIG. 5, first, a white screen is displayed on the color television receiver 1 to be inspected. Then, the optical filter 2 is converted into a red filter by the filter conversion device 11, and the photoelectric conversion element 3 is converted into a red filter.
A white screen is imaged by As a result, the color signal (ie, red signal) W _R (formula (9)) output from the photoelectric conversion element 3 is amplified by the amplifier 4 and stored in the storage device 5.

Next, a white screen is similarly imaged using the optical filter 2 as a green filter, and the obtained color signal (i.e., green signal) W _G (formula (9)) is amplified and sent to the storage device 5.
to be memorized. Further, the optical filter 2 is a blue filter, and the obtained color signal (i.e.,
The blue signal) W _B (formula (9)) is amplified and stored in the storage device 5. In this way, the storage device 5 stores each color signal W _R ,
W _G and W _B are stored.

Next, a screen with desired saturation is displayed on the color television receiver 1 to be inspected. First, the optical filter 2 is set as a red filter, and this screen is imaged by the photoelectric conversion element 3. As a result, the red signal V _R outputted by the photoelectric conversion element 3 (Equation (8))
is amplified by the amplifier 4 and supplied to the signal strength calculation device 6. In synchronization with this, the red signal W _R is read out from the storage device 5 and supplied to the signal strength calculation device 6. The signal strength calculation device 6 uses the supplied red signals V _R and W _R to calculate the above equation (10), and calculates the calculation result V _R /W _R to the saturation calculation device 7 and the hue calculation device. 8.

After the screen has been imaged with the red filter, the optical filter 2 is replaced with a green filter.
The photoelectric conversion element 3 images the screen with the desired chroma. The green signal V _G thus obtained is amplified and supplied to the signal strength calculation device 6, and at the same time, the green signal W _G is read out from the storage device 5 and supplied to the signal strength calculation device 6. . The signal strength calculation device 6 calculates the formula (10) using the green signals V _G and W _G and supplies the calculation result V _G /W _G to the saturation calculation device 7 and the hue calculation device 8. .

When the image of the screen with the desired saturation is completed for the green filter, the optical filter 2 is further converted into a blue filter, and in the same way, the signal strength calculation device 6 converts the blue signal V _B obtained from the photoelectric conversion element 3 into a blue filter.
The calculation of equation (10) is performed using the blue signal W _B read out from the storage device 5, and the calculation result is
V _R /W _R is supplied to a saturation calculation device 7 and a hue calculation device 8 .

Therefore, the saturation calculation device 7 calculates the equation (13) using the amplitude ratios V _R /W _R , V _G /W _G , and V _B /W _B of each supplied color signal, and calculates the amplitude e/W B. Calculate E _Y.
Similarly, the hue calculation device 8 calculates the phase angle Θ by calculating the equation (11). Obtained amplitude e/
Data representing E _Y is supplied to a saturation display device 9,
Further, data representing the phase angle Θ is obtained from the hue display device 1.
0, and the saturation and hue for the screen with the desired saturation are displayed.

In this way, in this embodiment, the saturation test can be performed without being influenced by the light emitting characteristics of the color television receiver to be tested or the characteristics of the photoelectric conversion element, so the test accuracy is improved and the test is not complicated. The color signals W _R , W _G ,
W _B can be used commonly and can perform rapid tests.

Furthermore, for different types of color television receivers to be tested with different emission characteristics, it is sufficient to simply replace the color signals stored in the storage device 5.
It does not require any adjustment or modification of the equipment, and performs the same processing operations for any type of color television receiver to be tested, simplifying the configuration and achieving faster and more accurate testing. can do.

In addition, in this implementation, the optical filter 2 is
Although the filter conversion device 11 replaces the red filter, green filter, and blue filter in this order, this is not necessary and the order of these color filters is arbitrary.

FIG. 7 is a block diagram showing another embodiment of the present invention, in which 2a is a red filter, 2b is a green filter, 2c is a blue filter, 3a, 3b, 3c are photoelectric conversion elements, and 4a, 4b, 4c are This is an amplifier, and parts corresponding to those in FIG. 5 are given the same reference numerals.

In this embodiment, three photoelectric conversion elements 3a, 3
b, 3c are provided, and optical filters having different transmittance characteristics, that is, a red filter 2a, a green filter 2b, and a blue filter 2c are provided. Note that each of the photoelectric conversion elements 3a, 3b, and 3c is a black-and-white television camera.

Next, the operation of this embodiment will be explained.

First, a reference white screen is projected onto the color television receiver 1 to be inspected, and the photoelectric conversion elements 3a, 3b, and 3c simultaneously transmit the white screen through the red filter 2a, green filter 2b, and blue filter 2c, respectively. Take an image. Photoelectric conversion elements 3a, 3b,
Red signal W _R and green signal obtained from 3c respectively
W _G and blue signal W _B are transmitted through amplifiers 4a, 4b, 4, respectively.
c and stored in the storage device 5.

Next, the color television receiver 1 to be inspected projects a screen with desired chroma, and this is transferred to the photoelectric conversion element 3.
a, 3b, and 3c simultaneously capture images. Red signals V _R obtained from the photoelectric conversion elements 3a, 3b, and 3c, respectively,
The green signal V _G and the blue signal V _B are transmitted through amplifiers 4a and 4a, respectively.
4b and 4c and supplied to the signal strength calculation device 6. In synchronization with this, the red signal W _R , the green signal W _G , and the blue signal W _B are simultaneously read out from the storage device 5 and supplied to the signal strength calculation device 6 .

The signal strength calculation device 6 uses the supplied color signals to perform the calculation of equation (10), and calculates the strength ratio of each color signal between the white screen and the screen with the desired saturation. below,
Similar to the embodiment shown in FIG. 5, the saturation and hue for the screen having the desired saturation are determined and displayed on the saturation display device 9 and the hue display device 10, respectively.

In this embodiment, photoelectric conversion elements 3a, 3
The spectral sensitivity characteristics of b and 3c do not necessarily have to match, and may have different spectral sensitivity characteristics. This now includes photoelectric conversion elements 3a, 3b,
The spectral sensitivity characteristics of 3c are Sa (λ), Sb (λ), and Sc, respectively.
(λ), the constant X expressed by the above formula (7),
_Y ^and _{Z are} ^, _{_} ＝∫ ^∞ ₀ B(λ)・F _B (λ)・S _c (λ)・dλ...(14) It is expressed as This is because the constants X, Y, and Z are irrelevant to the saturation and hue calculations because the saturation and hue are determined using the intensity ratio.

As described above, in this embodiment, each color signal can be obtained simultaneously without the need to replace the optical filter, so that the same effects as the embodiment shown in FIG. 5 can be obtained, and furthermore, A significant reduction in inspection time is achieved.

FIG. 8 is a block diagram showing still another embodiment of the present invention, in which 14 is a color television camera, and parts corresponding to those in FIG. 5 are given the same reference numerals.

In this embodiment, a color television camera 14 is used instead of an optical filter and a photoelectric conversion element.
outputs a red signal, a green signal, and a blue signal independently and simultaneously. The operation of this embodiment is similar to the embodiment shown in FIG.
Further, similar effects can be obtained, but since a single television camera is used, the configuration can be simplified.

The embodiments of the present invention have been described above, but in the present invention, when measuring the saturation of the screen of a color television receiver of the same model, that is, the same color phosphor, the standard is used. Imaging and memorizing a white screen, prior to measuring any saturation,
It's a good thing just to do it once in a while.

In addition, even if the model of the color television receiver to be inspected is changed and the emission characteristics of each color phosphor do not change, the white screen of the color television receiver to be inspected may be changed. All you need to do is take an image and store it, and no complicated adjustments are required.

In addition, in the above embodiment, it is assumed that the entire projection screen of the color television receiver to be tested is monochromatic, and the case where the saturation of the projection screen is tested is explained, but the present invention is not limited to this. For example, by projecting a color bar on a color television receiver to be tested and testing the saturation by partial imaging for each color band, it is possible to test the saturation of each color of the color bar at the same time.

Furthermore, according to the present invention, it is also possible to test the color density adjustment device of a color television receiver to be tested.

First, set the screen color of the color television receiver to be inspected to, for example, a red screen, set the color intensity control to the center point of the variable range (the click point if there is one), and then Measure phase and saturation (e/E _Y ).

This is shown in FIG. Standard red phase is B-Y
Θ=103.5° with respect to the axis, and the saturation is e ₀ .

On the other hand, it is confirmed that the measurement results for the projected screen of the color television receiver to be inspected are within the permissible range.

Next, turn the color depth control to either the dark or light limit and measure the saturation amplitude e ₁ at that time. Furthermore, turn the color saturation control to the limit in the opposite direction and measure the saturation amplitude e ₂ at that time.

The range e ₁ −e ₂ obtained through the above operations is the saturation variable range in the color television receiver to be inspected.

By the above method, it is possible to measure the variable range of screen saturation by adjusting the color density volume.

〔Effect of the invention〕

As explained above, according to the present invention, color signals are obtained by capturing images of a reference white screen and a screen of a desired saturation of a color television receiver to be inspected, and the intensity ratio of each color signal of these images is obtained. Since the chroma of the screen with the desired chroma is tested using This method maintains objectivity, improves the reproducibility of test results, and increases reliability.Furthermore, the circuit configuration does not become particularly complex, and it has excellent functions without the drawbacks of the conventional technology described above. A method and apparatus for testing color saturation of a color television receiver can be provided.

[Brief explanation of the drawing]

Figure 1 is a three-dimensional representation of the three attributes of color, Figure 2a is a CIE (Commission Internationale de l'Eclairage) chromaticity diagram, and Figure b is the color reproduction range of color television receivers, color films, and color printed matter. 3 is a waveform diagram of a color video signal, FIG. 4 is a vector diagram showing the phase angle and amplitude of each color, FIG. 5 is a block diagram showing an embodiment of the present invention, and FIG. Figure 5 is a characteristic diagram showing an example of the light emitting characteristics of each primary color phosphor of the picture tube in the color television receiver to be inspected; Figure b is a characteristic diagram showing an example of the transmission characteristics of the optical filter; 7 is a block diagram showing an example of the spectral sensitivity characteristics of a photoelectric conversion element, FIG. 7 is a block diagram showing another embodiment of the present invention, and FIG. 8 is a block diagram showing still another embodiment of the present invention. FIG. 9 is an explanatory diagram showing changes in the hue and saturation vectors due to the operation of the color density volume. 1...Color television receiver to be inspected, 2...
...Optical filter, 2a, 2b, 2c...Color filter, 3, 3a, 3b, 3c...Photoelectric conversion element, 5
...Storage device, 6...Signal strength calculation device, 7...
Saturation calculation device, 9...Saturation calculation device, 14...Color television camera.

Claims (1)

[Scope of Claims] 1. A color television receiver in which the projected screen of a color television receiver to be inspected is imaged to obtain an electrical signal, and the saturation of the projected screen is tested based on the electrical signal. In the method for testing the color saturation of a color television receiver, a standard white screen and a screen with a desired saturation are selectively projected on the color television receiver to be tested, and images of the white screen and the screen with the desired saturation are captured. The intensity ratio of each primary color light between the white screen and the screen with the desired saturation is obtained from each of the primary color signals obtained, and the intensity ratio is calculated to detect the saturation of the screen with the desired saturation. A method for testing color saturation of a color television receiver, characterized by: 2. A color saturation testing device for a color television receiver that captures an image of the projected screen of the color television receiver to be tested, obtains an electrical signal, and tests the chroma of the projected screen based on the electrical signal. a color pattern generator for selectively projecting a standard white screen and a screen of desired saturation on the color television receiver to be inspected; an imaging device that generates primary color signals, a storage device that stores each primary color signal when the projection screen is the white screen, and each primary color signal read from the storage device and the color television to be inspected. a first color signal that is supplied with each primary color signal obtained by imaging the screen of the desired chroma displayed on the receiver, and calculates an intensity ratio of each primary color signal between the white screen and the screen of the desired chroma; Detecting the saturation of the screen at the desired saturation, comprising a calculation device and a second calculation device to which data representing each intensity ratio obtained by the first calculation device is supplied and calculates saturation. 1. An inspection device for a color television receiver to be inspected, characterized in that the inspection device is configured to be able to perform the following operations.