JP2000115818A - Crt measurement instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the S/N ratio of a photographed image of a measured pattern which is displayed on a CRT. SOLUTION: A signal generator 4 outputs a video signal of a measured pattern displayed on a color CRT 6. A vertical synchronizing signal detection section 26 and a horizontal synchronizing signal detection section 27 detect a vertical synchronizing pulse and a horizontal synchronizing pulse from the video signal. A counter 251 in a control section 25 starts counting the vertical synchronizing pulse from a detection timing of the vertical synchronizing pulse, and when the count of the counter 251 reaches a count corresponding to a light emission start timing of a measured area set on a CRT display screen and a count corresponding to a light emission end timing, an exposure control signal generating section 252 outputs a control signal, consisting of an exposure start signal and an exposure stop signal to a CCD camera 3 respectively. The exposure of the CCD camera 3 is conducted only for the light emission period of the measured area, so as to prevent the deterioration in the S/N ratio of the image signal due to the exposure for the non-light-emission period other than the light emission period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CRT to be measured which is provided with a measurement region on a part of a display surface of the CRT to be measured and which uses image data obtained by capturing an emission image of the measurement region.
For measuring the light emission characteristics (characteristics of light emission amount, light emission color, etc.)
It relates to a T measuring device.

[0002]

2. Description of the Related Art Conventionally, a measurement pattern displayed on a CRT (Cathode Ray Tube) is changed for each period of a vertical synchronizing signal, and each measurement pattern is imaged. In the CRT measuring apparatus for measuring the image, the measurement pattern is changed every time one screen is scanned in the vertical direction. Therefore, in general, the start and end of exposure of the image pickup apparatus are controlled using a vertical synchronization signal.

For example, JP-A-3-44524 discloses that
2. Description of the Related Art In a CRT measuring apparatus for measuring a light emission color and luminance on a CRT tube surface, an interval time (interval of a synchronization pulse) of a vertical synchronization signal is measured, an imaging operation is performed for the interval time, and a light emission image displayed on the CRT is obtained. CRT to capture
Measuring devices have been proposed.

[0004]

By the way, in the CRT measuring apparatus described in Japanese Patent Application Laid-Open No. 3-444524,
Although the imaging device captures a light emission image of a measurement area provided on a part of the display surface of the CRT, the imaging operation (exposure of the image sensor) is performed during a period in which no light emission image is displayed in the measurement area. Therefore, an unnecessary dark current component is increased in the image signal output from the imaging device, and the S / S of the image signal is reduced.
There is a disadvantage that the N ratio decreases. That is, FIG.
As shown in (2), although the non-light-emitting periods t3 and t4 are also exposed despite the light-emitting period t2 being part of the exposure period t1 (interval period of the vertical synchronization signal), the light-emitting period t3 and t4 Dark current output from the photoelectric conversion element of the imaging device unnecessarily increases the noise component of the image signal,
This lowers the S / N ratio.

[0005] Even if the emission time of the phosphor in the measurement area ends, the exposure is continued until the synchronization pulse of the vertical synchronization signal is input, so that the start of the measurement processing is delayed at least during this exposure period. As a whole, the speed of the measurement process is reduced. That is, in FIG. 15, the exposure is performed unnecessarily during the period t4, and at least during the period t4, the start timing of the measurement process is delayed, so that the processing speed is reduced by that amount.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a CRT measuring apparatus capable of performing high-speed and high-accuracy CRT measurement by minimizing exposure during a period in which a measurement region does not emit light. To provide.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a CR to be measured.
In a CRT measuring apparatus for providing a measurement area on a part of the display surface of T and measuring the light emission characteristics of the CRT to be measured using image data obtained by imaging a light emission image of the measurement area, First input means for inputting a vertical synchronizing signal for driving of the CRT, imaging means arranged opposite to a measurement area on the display surface of the CRT to be measured, and imaging a light emission image of the measurement area; A synchronization pulse detection means for detecting a synchronization pulse of a vertical synchronization signal input from the input means; and a time counting means for counting time in a shorter cycle than the vertical synchronization signal when the synchronization pulse of the vertical synchronization signal is detected. Light emission start timing detection means for detecting the light emission start timing of a line including the upper end of the measurement area of the display surface of the CRT to be measured by the time counting means; When light emission start timing is detected by the detection means, in which a exposure control means for starting exposure of the imaging means (claim 1).

According to the above configuration, the driving vertical synchronizing signal input to the CRT to be measured for displaying the emission image for measuring the emission characteristics of the CRT is input to the CRT measuring apparatus,
The synchronization pulse (the start timing of screen scanning in the vertical direction) of the vertical synchronization signal is detected by the synchronization pulse detection means.

When the synchronization pulse of the vertical synchronizing signal is detected, the time is measured by the time measuring means in a cycle shorter than the period of the vertical synchronizing signal, and from the detection timing of the synchronizing pulse of the vertical synchronizing signal, the display surface of the CRT to be measured is displayed. When the light emission start timing of the line including the upper end of the measurement area is detected,
Exposure of the imaging means is started, and a light emission image of the measurement area is captured. Since the imaging operation is not performed during the period from the start of screen scanning in the vertical direction to the start of light emission of the measurement region, noise components of the image signal due to the exposure operation in the no-input state during this period are reduced.

Further, according to the present invention, in the above CRT measuring apparatus, there is provided light emission end timing detecting means for detecting the light emission end timing of a line including the lower end of the measurement area on the display surface of the CRT to be measured by the time measuring means. The exposure control means stops the exposure of the imaging means when the light emission end timing is detected by the light emission end timing means (claim 2).

According to the above structure, when the synchronization pulse of the vertical synchronization signal is further detected, the detection area of the measurement area on the display surface of the CRT to be measured is determined based on the detection timing of the synchronization pulse of the vertical synchronization signal based on the time measurement of the timer. The light emission end timing of the line including the lower end is detected, and the exposure of the imaging unit is stopped at the light emission end timing. When the light emission in the measurement area ends, without waiting for the end of vertical screen scanning,
Since the imaging operation is ended, the noise component of the image signal due to the exposure operation in the no-input state during the period from the end of light emission of the measurement area to the end of vertical screen scanning is reduced, and the end of light emission of the measurement area Later, the measurement process can be started immediately.

In the above CRT measuring apparatus, a second horizontal synchronizing signal for driving the CRT to be measured is inputted.
It is preferable that the timing means counts the number of synchronization pulses of the horizontal synchronization signal input from the second input means.

According to this configuration, when the synchronization pulse of the vertical synchronization signal is detected, the counting of the synchronization pulse of the horizontal synchronization signal is started, and when a predetermined count value corresponding to the emission start timing is reached, the light emission start timing is reached. When the detection signal reaches the predetermined count value corresponding to the light emission end timing, the light emission end timing detection signal is output.

Further, according to the present invention, a measurement area is provided on a part of the display surface of the CRT to be measured, and light emission characteristics of the CRT to be measured are obtained by using image data obtained by capturing an emission image of the measurement area. A CRT measuring apparatus for measuring C
Input means for inputting a vertical synchronizing signal and a horizontal synchronizing signal for driving the RT, imaging means arranged opposite to a measurement area on the display surface of the CRT to be measured and imaging a light emission image of the measurement area; Synchronizing pulse detecting means for detecting a synchronizing pulse of a vertical synchronizing signal inputted from an input means; and a time measuring means for counting a synchronizing pulse of the horizontal synchronizing signal and measuring time when a synchronizing pulse of the vertical synchronizing signal is detected. Information input means for inputting information on the display resolution of the CRT to be measured, the frequency of the horizontal synchronization signal, the center position of the measurement area on the display surface of the CRT to be measured, and the size of the measurement area; Using the information input from the input means, the exposure start timing and the exposure end time of the imaging means are determined with reference to the detection timing of the synchronization pulse of the vertical synchronization signal. The count value setting means for setting a count value of said counting means corresponding to the timing, the count value corresponding to the exposure start timing is counted by the clock means, to start exposure of the imaging means,
When the count value corresponding to the exposure end timing is counted by the timing unit, the exposure control unit terminates the exposure of the imaging unit.

According to the above configuration, the information of the display resolution of the CRT to be measured, the frequency of the horizontal synchronization signal, the center position of the measurement area on the display surface of the CRT to be measured, and the size of the measurement area are input from the information input means. Then, the count value setting means calculates and sets the count value C1 of the synchronization pulse of the horizontal synchronization signal from the detection timing of the synchronization pulse of the vertical synchronization signal to the light emission start timing. The count value C2 (> C1) of the synchronization pulse of the horizontal synchronization signal until the light emission end timing is calculated and set.

When the synchronization pulse of the vertical synchronization signal is detected, the counting of the synchronization pulse of the horizontal synchronization signal is started by the timer. When the count reaches the count value C1, the exposure of the imaging means is started, and the count value C2 is reached. , The exposure of the imaging means is stopped. That is, only the emission image of the measurement area on the display surface of the CRT to be measured is captured by the imaging unit.

The present invention also provides an input means for inputting a vertical synchronizing signal and a horizontal synchronizing signal for driving a CRT to be measured, and a measuring area provided in a partial area of a display surface of the CRT to be measured. An imaging unit that is disposed to face and captures a light emission image of the measurement area, a synchronization pulse detection unit that detects a synchronization pulse of a vertical synchronization signal input from the input unit,
When the synchronization pulse of the vertical synchronization signal is detected, the time synchronization means for counting the synchronization pulse of the horizontal synchronization signal and measuring the time, and the imaging means based on the detection timing of the synchronization pulse of the vertical synchronization signal. A count value setting unit that sets a count value of the timer unit corresponding to an exposure start timing and an exposure end timing; and, when a count value corresponding to the exposure start timing is counted by the timer unit, exposure of the imaging unit is performed. A CRT measuring apparatus comprising: an exposure control unit for starting the exposure and terminating the exposure of the imaging unit when a count value corresponding to the exposure end timing is counted by the timing unit; the plane in the vertical direction is divided into 2 ^m subregions, fringe number formed by combining the light emission and no light emission in each small area ^m (m = 1, 2, ... m) the m types of horizontal stripe patterns having a dichroic stripes of the sequentially to the measured CRT, a display control means for displaying, sequentially images of the m types of horizontal stripe pattern, The CRT to be measured is calculated by calculating the small area including the measurement area on the display surface of the CRT to be measured based on the image capturing control means to be captured by the imaging means and the image data of the m kinds of horizontal stripe patterns.
Measurement area calculation means for calculating the set position of the measurement area on the display surface of the, the count value setting means,
A count value corresponding to an exposure start timing and an exposure end timing of the imaging means is calculated and set based on a set position of the measurement area on the display surface of the measured CRT calculated by the measurement area calculation means. Item 5).

According to the above configuration, the display surface of the CRT to be measured is vertically divided into 2 ^m small areas, and the number of stripes 2 ^m (m) formed by combining light emission and non-light emission in each small area. =
1, 2,... M) m kinds of horizontal stripe patterns having two-color stripes are sequentially displayed on the CRT to be measured, and the CR to be measured is measured using image data obtained by imaging these horizontal stripe patterns.
The set position of the measurement area on the display surface of T is calculated.

That is, on the CRT to be measured, the display surface is vertically divided into two, four,..., 2 ^m , and m horizontal stripe patterns formed by alternately painting black from the top are sequentially displayed. In the display operation of the horizontal stripe pattern m times, a predetermined horizontal stripe pattern is displayed by emitting or not emitting light in each small area. Assuming that the area number of the i-th small area from the top of the display surface is i, the area number i of each small area is i =
_{^{Σ2 mn · k n (n =}} 1,2, ... m. However, when k _n = 1, does not emit light when that emits light in the n-th horizontal stripes pattern display is set to k _n = 0.) The Is calculated. Therefore, the set position of the measurement area on the display surface of the CRT to be measured is calculated by calculating the area number i of the small area included in the measurement area using the image data of the m horizontal stripe patterns.

Then, based on the set position of the measurement area on the display surface of the CRT to be measured, the count value setting means sets the count value of the synchronization pulse of the horizontal synchronization signal from the detection timing of the synchronization pulse of the vertical synchronization signal to the emission start timing. C1 is calculated and set, and the count value C2 (>) of the synchronization pulse of the horizontal synchronization signal from the detection timing of the synchronization pulse of the vertical synchronization signal to the emission end timing.
C1) is calculated and set.

When the synchronization pulse of the vertical synchronization signal is detected, the counting of the synchronization pulse of the horizontal synchronization signal is started by the timer, and when the count reaches the count value C1, the exposure of the imaging means is started and the count value C2 is started. , The exposure of the imaging means is stopped. That is, only the emission image of the measurement area on the display surface of the CRT to be measured is captured by the imaging unit.

[0022]

FIG. 1 is a block diagram of a measuring system of a CRT measuring apparatus according to the present invention.

The CRT measuring apparatus 1 comprises a data acquisition control unit 2, a CCD camera 3, a signal generator 4 and a measurement control unit 5, and the CCD camera 3, signal generator 4 and measurement control unit 5 are respectively shown in FIG. It is connected to the data acquisition control unit 2 by a substantially cable. Note that the data capture control unit 2
Is communicably connected to the measurement control unit 5. Also,
The color CRT 6 to be measured is connected to the signal generator 4 by a cable (not shown).

The CCD camera 3 detects the luminance of light emitted when a phosphor arranged on the display surface of the color CRT 6 emits light by irradiation with an electron beam. The CCD camera 3 is provided with an image sensor composed of a monochrome CCD area sensor and a fixed-focus photographing lens that forms an image of a measurement pattern displayed on a CRT display surface on the image surface of the image sensor. The CCD camera 3 performs exposure control according to an arbitrary shutter speed by controlling the charge accumulation time of the CCD area sensor. C
As shown in FIG. 3, the CD area sensor includes, for example, (horizontal 768 × vertical 484) pixels g arranged in a two-dimensional matrix. One pixel g is, for example, (horizontal 8.4 μm × (Vertical 9.8 μm).

The color CRT 6 to be measured is an electromagnetic deflection color CRT, and is a color CRT 6 for displaying an image.
1. A drive control circuit 62 for controlling the driving of the color cathode ray tube 61 is provided.

As shown in FIG. 4, the color CRT 61 has striped R (red), G (green) and B (blue) phosphors Fr regularly arranged in the horizontal direction on the back surface of the face plate. , Fg and Fb are baked to form a fluorescent screen 611. A blind grid type aperture grill 61 is provided at a predetermined interval in front of the fluorescent screen 611 in the cathode ray tube.
2 are provided. In the electron gun mount 613, three electron guns 614 are provided corresponding to the respective colors of R, G, and B, and a deflection yoke 615 is provided outside the tip of the electron gun mount 613.

The drive control circuit 62 controls an electron beam emitted from the electron gun 614 and corresponding to each of R, G, and B colors. The drive control circuit 62 controls the drive of the electron gun 61 based on the video signal (measurement pattern display signal) input from the signal generator 4.

The data acquisition control unit 2 controls the acquisition of data necessary for measuring the display characteristics of the color CRT 6, and specifically, controls the display of the color CRT 6 and the driving of the CCD camera 3. is there.

FIG. 2 is a block diagram of the data acquisition control unit 2. The data acquisition control unit 2 includes an A / D converter 2
1, VRAM (Video Random Access Memory) 22, R
AM (Random Access Memory) 23, ROM (Read Onl)
y Memory) 24, a control unit 25 including a microcomputer, a vertical synchronization signal detection unit 26, and a horizontal synchronization signal detection unit 2.
7 and a communication unit 28.

The A / D converter 21 converts a pixel signal (luminance signal captured by each pixel of the CCD 31) sent from the CCD camera 3 into a digital signal of, for example, 10-bit data. The VRAM 22 is a memory that stores a pixel signal (hereinafter, referred to as pixel data) A / D converted into a digital signal by the A / D converter 21. V
The RAM 22 has a storage capacity capable of storing an image captured by the CCD 31.

The ROM 24 is a memory in which a control program for measuring the display characteristics of the CRT is stored. The RAM 23 provides a storage area (work area) when the control unit 25 performs a series of arithmetic processing using the pixel data stored in the VRAM 22 according to the control program.

The control unit 25 centrally controls the operation of each unit in the data acquisition control unit 2, and displays the color CRT 6 and the CC.
It controls the capture of image data by the D camera 3 and also controls data communication with the measurement control unit 5.

Further, the control unit 25 has a counter 251 and the exposure control signal generation unit 252, as described later, the sync pulses S _V and the horizontal synchronizing signal of the vertical synchronizing signal included in the video signal of the measurement pattern C based on the synchronization pulse S _H
An exposure control signal for the CD camera 3 (a signal indicating an exposure start timing and an exposure end timing) is generated. The synchronization pulse _SV of the vertical synchronization signal is detected by the vertical synchronization signal detection unit 26, and the synchronization pulse S _{H of the} horizontal synchronization signal is detected.
Is detected by the horizontal synchronization signal detection unit 27.

The communication section 28 controls transmission of a drive control signal to the CCD camera 3 and the signal generator 4, transmission of an exposure control signal to the CCD camera 3, and data communication with the measurement control section 5.

Returning to FIG. 1, the signal generator 4 has a color CR.
It generates a predetermined measurement pattern signal displayed at T6, and is composed of, for example, a video generator. Signal generator 4, the electron beam Bm so may the predetermined display size is standardized raster scanning for the color CRT 6, predetermined vertical synchronizing pulses S _V and horizontal sync pulses S _H to the video signal indicative of the measurement pattern Are superimposed to generate a pattern signal.

The measurement control section 5 comprises a control section 51 comprising a personal computer, a display 52 such as a CRT, and a keyboard 53. The measurement control section 5 controls the operation of the CRT measuring apparatus 1 and is fetched by the data capture control section 2. The light emission characteristics of the color CRT 6 (for example, light emission color,
(Characteristics such as luminance) are calculated, and the result is displayed on the display 52 as necessary. Note that the calculation of the light emission characteristics is not related to the present invention, and a detailed description thereof will be omitted.

Next, a method of imaging a measurement pattern of the CRT measuring apparatus 1 according to the present invention will be described.

As described above, the imaging control of the CCD camera 3 is performed by the exposure control signal output from the data acquisition control unit 2. As shown in FIG. 5, the exposure control signal is such that the electron beam Bm of the color CRT 6 scans the vertical scanning area B including the measurement area A where the emission characteristics of the CRT display surface F are measured. Exposure operation (imaging operation) of the CCD camera 3 during the period when the phosphor in the inside is emitting light
, And comprises an exposure start timing signal S1 and an exposure end timing signal S2.

As is apparent from FIG. 5, the exposure start timing signal S1 is the first phosphor p1 of the horizontal line h1.
Is a timing signal for starting light emission, and an exposure end timing signal S2 is a horizontal line (h) next to the horizontal line h2.
2 + 1) is a timing signal at which the head phosphor p2 starts emitting light.

The control unit 25, the exposure start on the basis of the vertical synchronizing pulses S _V and horizontal sync pulses S _H timing signal S
1 and an exposure end timing signal S2, and outputs these timing signals to the CCD camera 3. That is, as shown in FIG. 6, when the vertical synchronization pulse _SV is input from the vertical synchronization signal detection unit 26, the control unit 25 resets the count value of the counter 251 (see timing a in FIG. 6), and starts counting up the horizontal synchronizing pulses S _H input from the synchronization signal detector 27. When the count value C of the counter 251 reaches a predetermined count value C1 set in advance, the exposure control signal generation unit 2
52, a detection signal S1 of the exposure start timing is output.
When the count value C of the counter 251 reaches a preset count value C2, the exposure control signal generator 252 outputs a detection signal S2 of the exposure end timing.

Accordingly, C is determined by the exposure control signals S1 and S2.
When the imaging of the CD camera 3 is controlled, the vertical synchronization pulse S
_With reference to the time point a at which _V is output, in FIG. 15, exposure (imaging) starts at time T1 after elapse of time t3, and ends at time T2 after elapse of time (t2 + t3). . Thereby, in FIG. 5, the CCD camera 3 scans the vertical scanning area B with the electron beam Bm so that the phosphor in the area B emits light.
Imaging is performed.

Incidentally, the above-mentioned exposure control signals S1 and S2
In the generation method of the counters 251, the count values C1, C2
Must be set in advance, but this count value C
1, C2 is the display size of the display surface F of the color CRT 6,
Resolution, the frequency of the horizontal synchronizing signal S _H, by inputting the center position of the measurement region A in CRT display surface F, the remaining of the light time condition of size and fluorescence of the measurement region A from the keyboard 53, as follows Calculated and set.

For example, if the size of the CRT display surface F is 316
(Horizontal) x 237 (vertical) [mm], display resolution 800
(Horizontal) × 600 (vertical) [dot], in a color CRT 6 in which a measurement pattern is displayed at a horizontal scanning frequency of 46.875 kHz, the pixel coordinate in the vertical direction is 100
Of the measurement area A of ± 10 mm length and width centered on the position of
Consider the case where T measurement is performed (see FIG. 7).

Assuming that the number of pixels (the number of lines) per 1 mm in the vertical direction is n, n = 600/237 = 2.53
Therefore, pixel coordinates h1, at the upper and lower ends of the measurement area A,
h2 (corresponding to the number of lines in the vertical direction) is as follows: h1 = 100−10 · n = 74.7 = 74 (rounded down below the decimal point) h2 = 100 + 10 · n = 125.6 = 126 (rounded up below the decimal point) . On the other hand, the emission time due to the afterglow of the phosphor is 50 μs.
, The scanning time τ per pixel is τ = 1
000 / 46.875 ≒ 21.3 μs, the h
The number α of lines scanned by the electron beam Bm while the two phosphors emit light is α = 2 (= 50 / 21.3).
(Rounded down to the nearest decimal point)). Therefore, the count values C1 and C2 are set so that the period in which the electron beam Bm scans from the 74th line to the 128th line is set as the exposure period.

The vertical synchronizing signal superimposed on the video signal has a waveform shown in FIG. 8 and has a vertical synchronizing pulse S _V (pulse width V
_SYNC ), a vertical back porch period V _BP , a vertical scanning period V _DISP, and a vertical front porch period V _FP are provided afterward.
_{After H} (pulse width H _SYNC ), a horizontal back porch period H _BP , a horizontal scanning period H _DISP and a horizontal front porch period H _FP are provided.

[0046] While the scanning of the head line of the vertical scanning is started after a vertical back porch period V _BP, the horizontal sync pulses S _H of the horizontal synchronizing signal count is started from the fall timing of the vertical synchronizing pulses S _V Therefore, as shown in the following equations (1) and (2), the count values C1 and C2 are calculated based on the pixel coordinates h1 at the upper end of the measurement area A and the pixel coordinates h2 at the lower end of the measurement area A. by subtracting "1" from the falling from converted into a value (the number of horizontal lines and the interval in terms of the count value of the horizontal sync pulses S _H until the end of the vertical back porch period V _BP of each vertical sync pulses S _V Is calculated as a value obtained by adding Δh.

[0047]

(Equation 1)

The reason why "1" is subtracted from the pixel coordinates h1 and h2 at the upper and lower ends of the measurement area A is that the line is counted at the end of horizontal scanning of each line. This is because when the 128th line is counted, the horizontal scanning of that line has been completed.

In the above-described method, the count values C1 and C2 are calculated from the display condition of the measurement pattern of the color CRT 6 and the set position of the measurement area A.
A plurality of horizontal stripe patterns having different numbers of stripes are sequentially displayed,
It is also possible to calculate the position of the measurement area A of the CCD camera 3 using the captured images of these horizontal stripe patterns, and calculate and set the count values C1 and C2 from this position information.

[0050] FIGS. 9 13, in which dividing the CRT display surface F in the longitudinal direction into two ^five regions were constructed five horizontal stripe pattern by combining a non-emission state and a light-emitting state of each area is there. The horizontal stripe pattern shown in FIG. 9 is obtained by dividing the CRT display surface F into two in the vertical direction, and painting the upper half black (non-light emitting state) and the lower half white (light emitting state). FIG.
The horizontal stripe pattern shown in FIG. 13 to FIG. 13 is obtained by dividing the CRT display surface F in the vertical direction into four, eight, sixteen, and thirty-two sections, and alternately painting black and white from above.

[0051] Each area divided into 2 ^five R (i) (i is C
This indicates that the area is the i-th area from the top of the RT display surface F. ), And the light emission state of each region R (i) when the horizontal stripe pattern is displayed in the order of FIGS.
When 0, b1, b2, b3, and b4 are indicated, and when each region R (i) emits light, “1” is set, and when each region R (i) does not emit light, “0” is set. The light emission information of each region R (i) obtained as shown in Table 1 below.

[0052]

[Table 1]

In Table 1, b4 to b0 indicating the light emitting state
Is a bit signal of each digit of 5-bit data D = (b4, b3, b2, b1, b0), as is clear from the table, the bit data D corresponding to each area number i is represented by the area number i. Is displayed in binary. Therefore, the region number i of each region R (i) can be known by determining the five light emission states b4 to b0. That is, the region number i of each region R (i) is i = b4 · 2 ⁴ + b3 · 2 ³ + b2 · 2 ² + b
Can be calculated by ^{1 · 2 1 + b0 · 2} 0. For example, the light emission states b4 to b0 are (b4, b3, b2, b1, b
0) = (0,1,0,0,0 if), regions with the emission state B4 to B0 R (i) ^{is, i = 0 · 2 4 +1} · 2 3
From +0 · ² 2 + 0 · 2 ¹ + 0 · 2 ⁰ = 8, it can be seen that a region R (8).

When the image picked up by the image pickup device of the CCD camera 3 includes light emission information of a plurality of regions R (i), R (i + 1),..., These regions R (i), R (i +
Since it is considered that the measurement area A is set over 1),..., The area numbers i, i of the areas R (i), R (i + 1),.
By knowing +1,..., It is possible to know in which area of the CRT display surface F the measurement area A is set.

If the region R (i) included in the measurement region A is known, the horizontal line included in the region R (i) can be known, and the upper and lower ends of the measurement region A are included from the line number of the horizontal line. Since the horizontal lines h1 and h2 or the horizontal lines h1 ′ and h2 ′ near them can be known, the count values C1 and h2 are obtained by using the above equations (1) and (2).
C2 is set.

In this embodiment, the CRT display surface F
The showed example of regions divided into two ^five, and not number of divided regions is not limited thereto, 2 ^m pieces (m is an integer) can be divided into appropriate number of. In this case, the number of stripes is 1
m m kinds of horizontal stripe patterns are sequentially arranged on the CRT display surface F,
, B2, and b1 are determined by using image data obtained by imaging each horizontal stripe pattern, and the area number i of each area R (i) is calculated. I just need.

In the case of using a single sensor or a line sensor instead of the CCD camera 3 to receive a light-emitting image displayed on the display surface of a color CRT, horizontal lines h1 and h2 including upper and lower ends of a measurement area are used. However, in this case, since the approximate position of the measurement area A on the CRT display surface can be determined from the area R (i) calculated from the captured image, The measurement area may be set by setting an area having a predetermined length. Note that even when such a rough measurement area is set, it is not necessary to accurately expose the light emission image during the light emission period of the photometry area A to capture the light emission image, and the light emission image is completely captured. Since it is sufficient to secure the minimum exposure period to be obtained, the effect is not remarkably reduced as compared with the case where the measurement region is accurately set.

Therefore, considering that strictness is not required in setting the measurement area, the above-described count value C
The latter method of setting C1 and C2 has an advantage that the operability is improved as compared with the former method, since it is not necessary to input calculation conditions such as the display size of the display surface F of the color CRT 6 and the like.

As described above, the exposure operation of the CCD camera 3 is performed only during the period of scanning the vertical scanning area B including the measurement area A on the CRTR display surface F.
As shown in FIG. 14, the exposure operation is not performed in the periods t3 and t4 during which the measurement area A does not emit light in the vertical scanning period t1 as in the related art, and the dark current component is reduced by that amount, so that the image data The S / N ratio is improved, and the dynamic lens becomes wider. As a result, CRT measurement accuracy is improved.

Further, the CRT measurement process can be started from the time point b (when (t2 + t3) has elapsed) when the scanning of the vertical scanning area B is completed, without waiting for the elapse of the vertical scanning period t1 as in the related art. The processing time can be reduced by the time T4, and the CRT measurement processing can be speeded up.

[0061] Incidentally, in the above embodiment, so that detecting the light emission period of the measurement region A of the vertical scanning period by counting the horizontal sync pulses S _H, the vertical non-horizontal sync pulses S _H it may be detected the light emission period of the measurement region a of the vertical scanning period with a short period of the signal from the synchronization pulse S _V.

For example, a dot clock output from a dot clock generator built in a video generator may be used. The dot clock is a reference clock for determining the video frequency. Using this dot clock, the horizontal scanning period H _{DISP of the} horizontal synchronizing signal and the period of the horizontal synchronizing signal (H _SYNC (sync pulse width) + H) based on the input horizontal resolution. _DISP (scanning period) + H _BP (back porch period)
+ Horizontal H _FP (front porch period)) is determined.

When the dot clock is used, the light emission timing can be detected in pixel units in the horizontal direction. For example, in FIG.
From the emission start timing of one point to q in the lower right corner of the measurement area A
It is preferable that the imaging operation of the CCD camera 3 is performed only during the period until the light emission end timing of two points. Or,
The exposure operation of the CCD area sensor may be performed intermittently so that the imaging operation is performed only during the light emission period of the photometry area A.

[0064] Further, using the clock of a predetermined frequency obtained a reference clock and the reference clock incorporated in the control unit and the data acquisition control unit of the video generator as a signal shorter than the vertical sync pulses S _V cycle by dividing You may do so.

[0065]

As described above, according to the present invention,
In a CRT measuring apparatus for measuring a light emission characteristic of a CRT to be measured by providing a measurement area on a part of a display surface of the CRT to be measured and using image data obtained by capturing a light emission image of the measurement area, The light emission start timing of the line including the upper end of the measurement area is detected from the detection timing of the signal synchronization pulse, and the exposure of the imaging means is started at this detection timing. The increase in the noise component due to the imaging operation in this period is reduced, and the S / N ratio of the captured image is improved, as compared with the case where the image is also captured during the period from the detection timing to the light emission start timing of the measurement region. Measurement accuracy is also improved.

Further, the light emission opening end timing of the line including the lower end of the measurement area is detected from the detection timing of the synchronization pulse of the vertical synchronization signal, and the exposure of the imaging means is ended at this detection timing. As described above, the increase in the noise component due to the imaging operation during the period from the emission end timing of the measurement region to the detection timing of the synchronization pulse of the next vertical synchronization signal is reduced as compared with the case where the imaging is performed during this period. The N ratio is further improved. In addition, since the start of the light emission characteristic measurement processing is not delayed until the next synchronization pulse detection timing of the vertical synchronization signal, the processing speed can be increased accordingly.

When the exposure start timing and the exposure end timing are detected by counting the synchronization pulse of the horizontal synchronization signal from the detection timing of the synchronization pulse of the vertical synchronization signal, the display resolution of the CRT to be measured and the frequency of the horizontal synchronization signal are determined. Since the count values of the exposure start timing and the exposure end timing are calculated and set from the information on the center position of the measurement region and the size of the measurement region on the display surface of the CRT to be measured, an accurate count value (that is, an accurate count value) Light emission period of the measurement area) can be set.

The display surface of the CRT to be measured is vertically divided into 2 ^m small areas, and the number of stripes 2 ^m (m = 1, 2) formed by combining light emission and non-light emission in each small area , ... m)
Measurement of m kinds of horizontal stripe patterns with two color stripes
T are sequentially displayed, and the count values of the exposure start timing and the exposure end timing are calculated and set using the image data of the m types of horizontal stripe patterns, so that the count values can be easily set and the CRT measurement can be performed. The operability of the device is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a measuring system of a CRT measuring apparatus according to the present invention.

FIG. 2 is a block diagram of a data acquisition control unit.

FIG. 3 is a diagram showing a pixel configuration of a CCD.

FIG. 4 is a perspective view of an essential part showing a structure of a face plate of an aperture grill type CRT.

FIG. 5 is a diagram illustrating a relationship between an imaging region and an exposure region on a CRT display surface.

FIG. 6 is a diagram for explaining a method of generating an exposure control signal from a vertical synchronization signal and a horizontal synchronization signal.

FIG. 7 is a diagram illustrating a specific example of a display size, a display resolution, and a size of a measurement area of a color CRT.

FIG. 8 is a diagram showing a waveform of a vertical synchronization signal.

FIG. 9 is a diagram showing a horizontal stripe pattern of two stripes displayed on a color CRT for calculating a count value.

FIG. 10 is a diagram showing a horizontal stripe pattern of four stripes displayed on a color CRT for calculating a count value.

FIG. 11 is a diagram showing a horizontal stripe pattern of eight stripes displayed on a color CRT for calculating a count value.

FIG. 12 is a diagram showing a horizontal stripe pattern of 16 stripes displayed on a color CRT for calculating a count value.

FIG. 13 is a diagram showing a horizontal stripe pattern of 32 stripes displayed on a color CRT for calculating a count value.

FIG. 14 is a diagram illustrating a relationship between a vertical synchronization signal, an exposure period, and a data processing period.

FIG. 15 is a diagram illustrating a relationship between a conventional vertical synchronization signal and an exposure period.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 CRT measuring device 2 Data acquisition control part (exposure control means, image acquisition control means, display control means) 21 A / D converter 22 VRAM 23 RAM 24 ROM 25 control part 251 Counter (time measuring means) 252 Exposure control signal Generation unit (light emission start timing detection unit, light emission end timing detection unit) 26 Vertical synchronization signal detection unit (synchronization pulse detection unit) 27 Horizontal synchronization signal detection unit 28 Communication unit 3 CCD camera (imaging unit) 4 Signal generator 5 Measurement control Unit (count value setting means, measurement area calculation means) 51 control unit 52 display unit 53 keyboard (first and second input means, input means,
Information input means) 6 color CRT 61 color CRT 62 drive control circuit

Claims (5)

[Claims] 1. A CRT for providing a measurement area on a part of the display surface of a CRT to be measured and measuring the light emission characteristics of the CRT to be measured using image data obtained by capturing an emission image of the measurement area. In the measuring apparatus, a first input means for inputting a vertical synchronization signal for driving the CRT to be measured is disposed opposite to a measurement area on a display surface of the CRT to be measured, and an emission image of the measurement area is captured. Imaging means for performing synchronization, a synchronization pulse detection means for detecting a synchronization pulse of a vertical synchronization signal input from the first input means, and a synchronization pulse shorter than the vertical synchronization signal when the synchronization pulse of the vertical synchronization signal is detected. A time counting means for counting time in a cycle; and a light emission start timing detecting means for detecting the light emission start timing of a line including the upper end of the measurement area on the display surface of the CRT to be measured by the time counting means. If, when the light emission start timing by the emission start timing detecting means is detected, CRT measuring apparatus characterized by comprising a an exposure control means for starting exposure of the imaging means. 2. The CRT measuring apparatus according to claim 1, further comprising: emission end timing detecting means for detecting emission end timing of a line including a lower end of a measurement area on a display surface of the CRT to be measured by the time measuring means. A CRT measuring device, wherein the exposure control means stops the exposure of the imaging means when the light emission end timing is detected by the light emission end timing means. 3. The CRT measuring apparatus according to claim 1, further comprising second input means for inputting a horizontal synchronizing signal for driving the CRT to be measured, wherein the time measuring means comprises the second input. A CRT measuring device for counting synchronization pulses of a horizontal synchronization signal inputted from the means. 4. A CRT for providing a measurement area on a part of the display surface of the CRT to be measured, and measuring the light emission characteristics of the CRT to be measured using image data obtained by capturing an emission image of the measurement area. A measuring device, comprising: input means for inputting a vertical synchronizing signal and a horizontal synchronizing signal for driving a CRT to be measured; and a light emitting image of the measuring region, which is disposed to face a measuring area on a display surface of the CRT to be measured. Image capturing means for capturing an image; a synchronous pulse detecting means for detecting a synchronous pulse of a vertical synchronous signal input from the input means; and a synchronous pulse of the horizontal synchronous signal when the synchronous pulse of the vertical synchronous signal is detected. A timer for counting and measuring time; a display resolution of the CRT to be measured, a frequency of the horizontal synchronizing signal, a center position of the measurement area on a display surface of the CRT to be measured, and a measurement area. Information input means for inputting information on the size of the image, and exposure start timing and exposure end timing of the imaging means based on the detection timing of the synchronization pulse of the vertical synchronization signal using information input from the information input means. When the count value corresponding to the exposure start timing is counted by the time counting means, the exposure of the imaging means is started, and the time counting means A CRT measuring apparatus, comprising: an exposure control means for terminating the exposure of the imaging means when a count value corresponding to the exposure end timing is counted. 5. An input means for inputting a vertical synchronizing signal and a horizontal synchronizing signal for driving a CRT to be measured, and a measuring area provided in a partial area of a display surface of the CRT to be measured. Imaging means for capturing an emission image of the measurement area; synchronization pulse detection means for detecting a synchronization pulse of a vertical synchronization signal input from the input means; A timer for counting a synchronization pulse of a synchronization signal to measure time; and a count of the timer corresponding to an exposure start timing and an exposure end timing of the imaging unit based on a detection timing of the synchronization pulse of the vertical synchronization signal. Count value setting means for setting a value; and when the count value corresponding to the exposure start timing is counted by the timing means, the imaging means An exposure control means for ending exposure of said imaging means when exposure is started and a count value corresponding to said exposure end timing is counted by said timing means; Is vertically divided into 2 ^m small areas, and two colors of 2 ^m (m = 1, 2,... M) stripes formed by combining light emission and non-light emission of each small area. Display control means for sequentially displaying m types of horizontal stripe patterns having stripes on the CRT to be measured; image capture control means for sequentially capturing images of the m types of horizontal stripe patterns with the imaging means; By calculating a small area including the measurement area on the display surface of the CRT to be measured based on the image data of the type of horizontal stripe pattern, the set position of the measurement area on the display surface of the CRT to be measured is calculated. The count value setting means, wherein the count value setting means calculates the exposure start timing and the exposure end of the imaging means based on the measurement area set position on the display surface of the CRT to be measured calculated by the measurement area calculation means. A CRT measuring apparatus for calculating and setting a count value corresponding to a timing.