JP3366374B2 - Image quality measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the convergence of color screens in color cathode ray tube adjustment, quality control, etc.
The present invention relates to an image quality measuring device for measuring chromaticity and color purity.

[0002]

2. Description of the Related Art Generally, color cathode ray tubes (hereinafter referred to as CR
T) is made so that three electron beams of red, green, and blue (hereinafter, R, G, and B) emit each phosphor on the tube surface. There are color purity adjustments so that the electron beams of the book exactly hit the respective phosphors on the tube surface, and convergence adjustments so that the three electron beams are concentrated on one point of the tube surface.
In addition, as the CRT adjustment, there is chromaticity adjustment for adjusting the chromaticity indicating a color attribute on the xy chromaticity coordinates.

FIG. 8 is a diagram showing mutual interference of each adjustment item of convergence, chromaticity, and color purity in CRT adjustment. FIG. 8 shows how one adjustment interferes with another adjustment item, and the solid line indicates a direct interference that immediately affects another adjustment item when the adjustment is performed, and the arrow indicates the direction. It represents the direction of interference. Further, the broken line means that adjustment items other than convergence, chromaticity, and color purity are influenced, and interference is caused by readjusting the influenced items.

That is, for example, if the color purity is adjusted, the convergence and the chromaticity will change. Because of this, it is not possible to make independent adjustments, so convergence work is performed by making repeated adjustments. FIG. 9 is a diagram showing a flow chart of an adjustment process for performing such a convergence work, and here, adjustment items other than convergence, chromaticity, and color purity are omitted.

In the adjustment process of FIG. 9, first, the convergence of the central portion of the screen of the CRT is roughly adjusted (step 100),
The color purity is adjusted (step 101). Next, accurately adjust the convergence in the center of the screen (step 10
2) Adjust the convergence in the peripheral area of the screen (step 103). Then, the chromaticity is adjusted (step 10
4) Confirm the above-mentioned convergence, chromaticity, and color purity adjustment (step 105) and move to the next adjustment step (step 1)
06). The above-mentioned interference is avoided by carrying out the convergence operation in which the adjustment steps are repeatedly performed through such adjustment steps.

For the image quality measurement in each of such adjustments, a separate image quality measuring device is installed exclusively for each adjustment item and each adjustment item is set as a different process in a different work place, or these image quality measuring devices are installed in one place. Thus, an operator selectively uses each measuring device according to an adjustment item, or a plurality of measuring devices are provided with a moving mechanism to form one device, thereby performing one adjusting process.

[0007]

Since the conventional image quality measurement has been performed as described above, the measuring method in which separate image quality measuring devices are used as separate steps is labor-intensive and requires a long adjustment process. There was the problem of taking up space. Also,
In the method in which the operator uses the measuring device properly according to the measurement item, there is a problem that the burden on the operator is large because there are a plurality of adjustment items. There were problems such as frequent mistakes and movement time unrelated to measurement. In addition, since the deviation of the measurement points cannot be avoided by any of the methods, it is difficult to perform measurement at the same measurement point, and it is difficult to perform highly accurate measurement in a short time.

In order to solve the above problems, it is an object of the present invention to provide an image quality measuring device capable of easily measuring with high precision in a short time and measuring convergence, chromaticity, and color purity at the same point. To do.

[0009]

A first image quality measuring device according to the present invention is an image quality measuring device for measuring the convergence of a color CRT using a CCD element, wherein light emitted from the color CRT is applied to the CCD element. An optical lens for forming an image and the vicinity of the focus of the optical lens
And the ratio of affecting the optical path of the optical lens is
A color filter that is fixedly installed at a position where the number is the smallest , transmits a light emitted from the color CRT, and a sensor for measuring chromaticity or color purity that converts an optical signal transmitted through the color filter into an electric signal. It is equipped with.

A second image quality measuring device according to the present invention comprises a color filter of the image quality measuring device according to the first invention as C
Three color filters having spectral sensitivities equal to the CIE color matching function corresponding to the three stimulus values of the IE color system are provided, and three sensors for converting the amount of light transmitted through each of these color filters into an electric signal are provided. It is a thing.

A third image quality measuring device according to the present invention comprises the color filter of the image quality measuring device according to the first invention.
3 color filters having a spectral sensitivity that transmits only the R, G, and B wavelength bands are used, and the amount of light transmitted through each of these color filters is converted into an electrical signal 3.
One sensor and a sub-deflection coil that deflects the electron beam of the color CRT from the outside of the tube surface during measurement by the sensor.

[0012]

According to the present invention, the sensor section or the first sensor section has a spectral sensitivity equal to the CIE color matching function.
The light of the image of the color CRT transmitted through the color filters is converted into an electric signal by the sensor corresponding to each color filter, and the tristimulus value X of the image at the same position as the image of the color CRT imaged by the CCD element , Y, Z are output from the sensor.

Further, the sub-deflection coil locally deflects the electron beam of the color cathode ray tube from the outside of the tube surface, and the sensor section or the second sensor section has a spectral sensitivity of transmitting only the R, G, and B wavelength bands. The light of this color cathode ray tube that has transmitted through the three color filters that it has is converted into an electrical signal by the sensor corresponding to each color filter, and the R signal of the image at the same position as the image of the color cathode ray tube captured by the CCD element, The G signal and the B signal are output from the sensor.

[0014]

FIG. 1 is a sectional view of an image quality measuring apparatus showing one embodiment of the present invention, and FIG. 2 is a block diagram of this image quality measuring apparatus. 1 is a CRT, 2 is a camera lens section, 2a is a camera lens attached to the camera lens section 2, 3 is a CCD camera section for measuring convergence, and 3a is a CRT
CCD element for converting the image of 1 into an image signal, 4 is a CCD
A convergence processing circuit for processing the image signal output from the element 3a, 5 is a sensor unit for measuring chromaticity and color purity, 5a is a chromaticity sensor unit (first sensor unit),
5b is a color purity sensor section (second sensor section), 6a, 6b
Is a luminance signal processing unit for processing the signals output from the chromaticity sensor unit 5a and the color purity sensor unit 5b, 7 is a sub-deflection coil unit for deflecting the electron beam of the CRT 1 in measuring the color purity, and 7a is A sub-deflection coil having two sets of coils for horizontal deflection and vertical deflection, and 8 is a coil drive circuit for supplying a drive current to the sub-deflection coil 7a.

Further, 15 is an outer cylinder for supporting the measuring portion such as the camera lens portion 2, CCD camera portion 3, sensor portion 5, sub-deflection coil portion 7 and the like of this image quality measuring device, and 16 is a spring and an outer cylinder which will be described later. A holder which is supported by 15 and to which the CCD camera unit 3 and the sensor unit 5 are attached, 1
Reference numeral 7 is a spring, 18 is a micrometer for adjusting the focal position of the camera lens 2a, 19 is a column for attaching the sub deflection coil unit 7 to the sensor unit 5, and 30 is a CRT.
The optical path of the image from 1, 31 is the focal position of the camera lens 2a.

In FIG. 2, 6 is a luminance signal processing section 6a,
6b is a brightness signal processing circuit, 9 is a convergence processing circuit 4, a brightness signal processing circuit 6, a coil driving circuit 8, a signal generator to be described later, and a CPU. An input / output interface 10 for exchanging data is a CP for controlling the image quality measuring device and calculating measurement values based on a command from an operator.
U and 11 are operation panels for the operator to give instructions to the CPU 10, 12 is a monitor for displaying the operating state of the image quality measuring device and the measurement result, and 13 is a video signal for displaying an image for measurement on the CRT 1. It is a signal generator to output.

The holder 16 of this image quality measuring device is supported by an outer cylinder 15 attached to a not-shown installation table or the like, and is moved back and forth by a micrometer 18. The focus position 31 of the camera lens 2a can be easily adjusted by the micrometer 18.

The sensor section 5 has a chromaticity sensor section 5a and a color purity sensor section 5b built therein.
The color purity sensor unit 5b is installed near the rear focus position 31 of the camera lens 2a. These are focal points 3
1, the optical path 30 of the image of the CRT 1 that has passed through the camera lens 2a is most narrowed near the focal point 31 as shown in FIG. 1, and therefore the ratio of affecting the optical path 30 is the smallest. Because.

The sensors described later in the chromaticity sensor section 5a and the color purity sensor section 5b face the CRT1 direction in FIG. 1, and the light of the image of the CRT1 passing through the camera lens 2a (what is the main optical path 30? Another optical path) is incident. In addition, the sub deflection coil 7a is a CRT1.
In addition to the deflection of the electron beam by the inner deflection yoke, it is installed to locally deflect the electron beam from the outside of the tube surface.

Next, as an operation of such an image quality measuring apparatus, first, convergence measurement will be described with reference to FIG. When the operator operates the operation panel 11 and gives a command for measuring the convergence to the CPU 10, the CPU 10 controls the signal generator 13 via the input / output interface 9,
The signal generator 13 outputs, for example, a checkered cross-hatching signal to the CRT 1 for display.

Then, the light of the image reflected on the CRT 1 enters through the camera lens 2a built in the camera lens unit 2 as shown by the optical path 30 in FIG. Capture an image. Next, the R signal, G signal, and B signal of the image signal thus obtained are simultaneously input to the convergence processing circuit 4 in synchronization with the synchronization signal output from the signal generator 13 to the convergence processing circuit 4, Signal amplification and A / D
Signal processing such as conversion is performed.

Next, the R signal, G, which have been subjected to these processes,
A signal and a B signal are input to the CPU 10 via the input / output interface 9, and the CPU 10 causes, for example, R,
The misconvergence amount is calculated by calculating the center of gravity of the R, G, and B electron beams from the G and B luminance distributions. In this way, the convergence is measured and the result is displayed on the monitor 12.

Next, the chromaticity measurement will be described. The chromaticity sensor section 5a has three built-in sensors and three color filters. 3 is a block diagram showing an embodiment of the chromaticity sensor unit 5a, FIG. 4 (a) is a diagram showing the spectral sensitivity of the color filter of this chromaticity sensor unit 5a, and FIG. 4 (b) is the International Commission on Illumination ( It is a figure which shows the color matching function of a CIE) standard color system.

In FIG. 3, 50, 51 and 52 are CRTs.
A color filter for dispersing the light of the image No. 1 to obtain the stimulus values X, Y, Z of the CIE standard color system, 53,
54 and 55 are color filters 50, 51 and 5, respectively.
The amount of light that has passed through 2 is converted into an electrical signal, and the stimulus value X,
It is a sensor that measures Y and Z. In FIG. 4 (b),
Bars x, y, and z are color matching functions of the CIE standard color system.

That is, the color filters 50, 51,
Reference numeral 52 has spectral sensitivities equivalent to those of the color matching function bars x, y, and z, respectively, so that stimulation values X, Y, and Z can be obtained.

Next, the operation will be described. When an operator operates the operation panel 11 and gives a command for measuring chromaticity to the CPU 10, the CPU 10 controls the signal generator 13 via the input / output interface 9, and the signal generator 13 causes the CRT 1 to operate.
A white pattern raster signal in which the entire screen is white is output to display the white pattern on the CRT 1. Then, the light of the image of the CRT 1 that has passed through the camera lens 2a is dispersed by the color filters 50, 51, 52 of the chromaticity sensor unit 5a, and the stimulus values X, Y, Z are measured by the corresponding sensors 53, 54, 55, respectively. To be done.

Then, the stimulation values X, Y, and
Z is input to the luminance signal processing circuit 6 in synchronization with the synchronization signal output from the signal generator 13 to the luminance signal processing circuit 6, and signal processing such as signal amplification and A / D conversion is performed. And
The stimulus values X, Y, and Z that have been subjected to these processes are input to the CPU 10 via the input / output interface 9, and the CPU
From 10 stimulus values X, Y, Z to chromaticity coordinates (x, y)
Is calculated. Thus, the chromaticity is measured and the result is displayed on the monitor 12.

Next, the measurement of color purity will be described. The structure of the color purity sensor unit 5b is the same as that of the chromaticity sensor unit 5a of FIG. 3, but the spectral sensitivity of the color filter is different from that of the color filters 50, 51, 52 of FIG. FIG. 5 is a diagram showing the spectral sensitivity of the color filter in the color purity sensor section 5b. As described above, a color filter having a spectral sensitivity capable of easily separating R, G, and B is used.

That is, assuming that the color filters 50, 51 and 52 in FIG. 3 are color filters having the spectral sensitivities of R, G and B shown in FIG. 5, respectively, the sensors 53, 54 and 55 in FIG. ,
It becomes a sensor that converts the amount of light that has passed through 51 and 52 into an electric signal and measures the R, G, and B signals.

Next, the operation will be described. When the operator operates the operation panel 11 to give a command for measuring the color purity to the CPU 10, the CPU 10 controls the signal generator 13 via the input / output interface 9 so that the signal generator 13 outputs R,
The color signal of the color to be measured of G and B, for example, R is output as the raster signal of the R pattern and displayed on the CRT 1. Therefore, the R signal is obtained from the R signal sensor (53 in FIG. 3). At this time, the coil drive circuit 8 supplies a drive current to the sub deflection coil 7a in accordance with a command output from the CPU 10.

By the magnetic field generated by this drive current, the electron beam with which the phosphor of the CRT 1 is irradiated is sub-deflected by the same amount from the outside of the tube surface to the left and right. The R signal thus obtained is input to the luminance signal processing circuit 6 in synchronization with the synchronization signal output from the signal generator 13, and is used for signal amplification and A /
Signal processing such as D conversion is performed. Next, the R signal that has been subjected to these processes is transferred to C via the input / output interface 9.
The data is input to the PU 10, and the CPU 10 calculates the mislanding amount (deviation amount between the electron beam and the phosphor) which is an index of color purity.

Here, the state in which the color purity is good is a state in which the phosphor emits the electron beam most efficiently, and the center of the electron beam and the center of the phosphor coincide with each other. When the electron beam is laterally displaced by the external magnetic field in this state, the intensity characteristic of the obtained luminance signal becomes a curve which becomes maximum when the electron beam coincides with the phosphor and gradually decreases on the left and right.

Therefore, the mislanding amount of R can be calculated by knowing how much is present from the point of this maximum output. Similarly, the G and B raster signals are output to the signal generator 13 to measure the G and B mislanding amounts, respectively. In this way, the color purity is measured and the result is displayed on the monitor 12.

In this way, the convergence, chromaticity, and color purity can be measured by one image quality measuring device, and since the measuring device is not moved, it is possible to easily measure at the same measuring point in a short time. It can be carried out.

Although one image quality measuring device is provided in the embodiment shown in FIG. 1, a plurality of image quality measuring devices can be provided to simultaneously measure a plurality of points. FIG. 6 is a diagram showing an installation example of an image quality measuring device showing another embodiment of the present invention, and 40 is the image quality measuring device of FIG. FIG. 6 is a view of the CRT 1 viewed from the image quality measuring device 40 side, and it can be seen that the image quality measuring device is provided at nine points.

By doing so, in one image quality measuring device such as the uniformity of luminance, the uniformity of chromaticity, the raster distortion, etc. from the respective data of the convergence, chromaticity and color purity at each position of the CRT 1. It is possible to measure difficult inspection items in a short time and without shifting the measurement points.

Further, in the above embodiment, the focus position 31 of the camera lens 2a can be adjusted by using the manual micrometer 18, but an electric micrometer may be used. FIG. 7 is a cross-sectional view of an image quality measuring apparatus showing another embodiment of the present invention, showing only a portion centering on the outer cylinder 15. 28 is an electric micrometer,
An image processing unit 29 determines the focus of the image based on the image signal from the CCD 3a and controls the electric micrometer 28.

The configuration and operation of the image quality measuring apparatus of this embodiment are basically the same as those of the example of FIG.
Based on the image signal from the CCD element 3a, it is determined whether or not the image is in focus, and the drive amount of the electric micrometer 28 is determined from this determination result to drive the electric micrometer 28. Therefore, the focus position 31 of the camera lens 2a can be automatically adjusted by moving the holder 16.

[0039]

According to the present invention, in an image quality measuring device for measuring the convergence of a color CRT using a CCD element, an optical lens for forming an image of the light emitted from the color CRT on the CCD element, There is a shadow in the optical path of the optical lens near the focal point of the optical lens.
Ratio on the sound is installed and fixed to the smallest a position, mosquito that transmits light emitted from the color CRT
Color filter and the chromaticity or color purity measurement for converting an optical signal into an electrical signal which has been transmitted through the color filter
Since it is provided with a sensor for use, it is possible to simplify the operation and reduce the waste of moving time. Further, according to the present invention, in the sensor unit installed so that the light of the image at the same position as the image of the color CRT imaged by the CCD element is incident, it has a spectral sensitivity equal to the CIE color matching function.
The light of the image of the color cathode ray tube that has passed through the color filters is converted into an electric signal by the sensor corresponding to each color filter, and the tristimulus values are output from the sensor. It is possible to measure chromaticity at the same measurement point in a short time with high accuracy, reduce the number of adjustment steps and workers, and improve and stabilize quality.

Further, in the sensor portion installed so that the light of the image at the same position as the image of the color CRT imaged by the CCD element is incident, it has a spectral sensitivity of transmitting only the wavelength bands of R, G and B. The light of the color cathode ray tube, in which the electron beam is locally deflected and which has passed through the three color filters, is converted into an electric signal by a sensor corresponding to each color filter, and an R signal, a G signal, and a B signal.
Since the signal is output from the sensor, it can be measured in a short time with high accuracy at the same measuring point convergence and color purity by a single image quality measurement device, Ya adjustment step
We can reduce the number of workers and improve and stabilize quality.
Can be planned.

[0041]

[Brief description of drawings]

FIG. 1 is a sectional view of an image quality measuring apparatus showing an embodiment of the present invention.

FIG. 2 is a block diagram of the image quality measuring device of FIG.

FIG. 3 is a block diagram showing an embodiment of the chromaticity sensor unit of FIG.

4 is a diagram showing the spectral sensitivity of the color filter of the chromaticity sensor unit of FIG. 1 and the color matching function of the CIE standard color system.

5 is a diagram showing the spectral sensitivity of the color filter of the color purity sensor unit of FIG.

FIG. 6 is a diagram showing an installation example of an image quality measuring apparatus showing another embodiment of the present invention.

FIG. 7 is a cross-sectional view of an image quality measuring device showing another embodiment of the present invention.

FIG. 8: Convergence, chromaticity, and
It is a figure which shows the mutual interference of each adjustment item of color purity.

FIG. 9 is a diagram showing a flowchart of an adjustment process for performing a convergence work.

[Explanation of symbols]

1 CRT 2a camera lens 3a CCD element 4 Convergence processing circuit 5a Chromaticity sensor section 5b Color purity sensor section 6 Luminance signal processing circuit 7a Sub deflection coil 8 coil drive circuit 50, 51, 52 color filters 53, 54, 55 sensors

Claims (3)

(57) [Claims] 1. A quality measuring device for measuring the convergence of a color picture tube using a CCD element, and an optical lens for focusing light emitted from the color CRT to the CCD element, near the focal point of the optical lens Yes, of the optical lens
Affecting the proportion in the optical path is installed and fixed to the smallest a position, converting the color <br/> filter which transmits light emitted from the color CRT, an optical signal into an electrical signal which has been transmitted through the color filter And a sensor for measuring chromaticity or color purity . 2. The color filters are three color filters having a spectral sensitivity equal to the CIE color matching function corresponding to the three stimulus values of the CIE color system, and transmitted through each of the color filters. The image quality measuring device according to claim 1, further comprising three sensors that convert a light amount into an electric signal. 3. The color filters are three color filters having a spectral sensitivity of transmitting only the R, G, and B wavelength bands, and converting the amount of light transmitted through each of the color filters into an electric signal. The image quality measuring device according to claim 1, further comprising: three sensors for controlling the image quality, and a sub-deflection coil for deflecting the electron beam of the color CRT from the outside of the surface of the tube during measurement by the sensor.