JPS61277135A - Convergence measuring device for picture tube - Google Patents

Abstract

PURPOSE:To compute centers of gravity of beams R, G, and B accurately, by computing the centers of the beams, that is, the centers of gravity, from all the brightness data crossing sampling lines. CONSTITUTION:Responding to the phosphor stripes R, G, and B arranged in order with specific pitches horizontally to a cathode-ray tube screen, at least three data sampling lines 2R, 2G, and 2B are established vertically respectively, and measuring patterns for R, G, and B are moved at a time horizontally in specific pitches. Each brightness data in the vertical direction in the measuring pattern area on R, G, and B at each data sampling line in every horizontal movement pitch is memorized in order. This brightness data measurement is continued until the beams pass through the sampling lines perfectly. Depending on these brightness data, each center of R, G, and B is computed, and the convergence condition is measured depending on the data from these centers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a picture tube convergence measuring device suitable for application to various image display devices.

[Summary of the invention]

The present invention relates to a convergence measuring device for a picture tube suitable for application to various image display devices, and particularly to R and G convergence measurement devices that have passed through an electron beam arrival position determining electrode.

The center point of each measurement pattern of R2O and B is calculated from the brightness data of the entire shape of the beam spot obtained when each beam spot of B is sequentially moved at a predetermined pitch in the horizontal scanning direction, and the center point of each measurement pattern of R2O and B is calculated. By measuring the convergence state based on the data, R,
The center point of each of G and B can be accurately measured, thereby making it possible to easily and reliably determine whether the convergence is good or bad.

[Conventional technology]

Convergence measurement to measure the degree of concentration of electron beams corresponding to each of the R, G, and B phosphors in a color picture tube can be done visually or by using a measuring device, and as far as measurement accuracy is concerned, the convergence measurement is done visually. It is better to use the device. An example of using a measuring device is JP-A-59-7
This is already known from Publication No. 4781 and the like.

This measuring device applies an electron beam to any phosphor to be measured through an electron beam arrival position determination electrode such as a shadow mask or aperture grill.
The center (beam center of gravity) is determined by calculating the display area corresponding to the beam shape. In this case, depending on the display position of the electron beam pattern,
-D, the positional relationship between the dot pattern (the dot pattern G in the figure) and the phosphor G changes.

If the positional relationship between the measurement dot pattern and the phosphor changes in this way, the center of gravity of the phosphor in the measurement pattern (
The center of gravity of the measurement result changes with respect to the true center of gravity position 0. Since this deviation results in a measurement error, the prior art described above takes the following measures to avoid this measurement error.

In other words, by focusing on the fact that the measured value of the center of gravity changes trigonometrically with respect to the positional relationship between the measurement pattern and the phosphor,
When a measurement pattern is imaged at an arbitrary positional relationship, for example, T1 in FIG. 13, a position symmetrical to this positional relationship (
By generating a measurement pattern at T2 (1/2 of the phosphor arrangement pitch), capturing an image of the pattern, and finding the average value of each, the error in the measurement value can be offset and the measurement accuracy can be improved. It is something that

[Problem that the invention seeks to solve]

By the way, even with such a conventional convergence measuring device, it is not possible to accurately determine the beam concentration degree.

That is, the above-mentioned measuring device cancels the error caused by the mutual relationship between the beam spon 5 position and the phosphor position by moving the dot signal on the CRT by 1/2 pitch. Since the method calculates the center of gravity position based on the imaging information of the beam spot shape that is missing from the electron beam arrival position determination electrode, there is always a calculation error of the beam spot center of gravity, and the accumulation of these errors will affect the convergence measurement. This is because it appears as an error.

Therefore, this invention solves these conventional problems, and makes it possible to accurately calculate the beam center even when the beam spot shape is deformed by the electron beam arrival position determining electrode. This improves the accuracy of convergence measurement.

[Means for solving problems]

In order to solve the above-mentioned problems, in the present invention, as shown in FIGS. At least three data sampling lines are set in the vertical direction corresponding to each body stripe, and each measurement pattern of R, G, and B is simultaneously moved horizontally at a predetermined pitch, and each horizontal movement pitch is Then, the luminance data in the vertical direction in each measurement pattern area regarding R, G, and B on each data sampling line is sequentially memorized. Measurement of brightness data is performed until the beam has completely passed through the sampling line.

The center points of each of the R, G, and B measurement patterns are calculated based on these luminance data, and the convergence state is measured based on the data of these center points.

[Effect]

According to this configuration, the center of the beam, that is, the center of gravity of the binim, is calculated from all the luminance data that crosses the sampling line, so it is possible to accurately calculate the center of gravity for each of the R, G, and B beams. . If the center of gravity of each beam can be calculated accurately, the degree of concentration of the beam can also be calculated accurately from these centers of gravity, thereby improving the accuracy of convergence measurement.

〔Example〕

FIG. 1 is a system diagram showing an example of a picture tube convergence measuring device 10 according to the present invention, but for convenience of explanation,
The measurement principle of this invention will first be explained with reference to FIG. 7 and subsequent figures.

In FIG. 7A, R, G, and B indicate striped phosphors arranged horizontally at a predetermined pitch, and any phosphor among these, in this example, the G phosphor A data chimpling line 2G is virtually set at the corresponding position. A plurality of sampling points are set on the data sampling line 2G at predetermined intervals in the vertical direction, and only the luminance data emitted on the data sampling line 2G is stored in the memory for each sampling point.

The relationship between the data transfer line and the image memory (described later) is shown in FIG. 7B.

The electron beam spot 1 that has passed through the electrode for determining the electron beam arrival position reaches the phosphor, and if you pay attention only to the phosphor G, it will emit light as shown by diagonal lines, and move the electron beam spot 1 in the direction of arrow a ( If the data sampling line 2G is moved sequentially at a predetermined pitch in the horizontal direction
The light emitting area at the top increases as it approaches the beam center OG, and gradually decreases beyond the center.

From this, when the luminance distribution on the data sampling line 2G is measured, it becomes a single peak data curve as shown in FIG. In this figure, K is beam spot 1
If K = 0 is the pitch when the beam emission area does not overlap the data sampling line 2G, and the beam spot 1 moves to the left as K increases, the brightness distribution will be as follows: It is maximum at the center and minimum around it.

Measure the distribution of brightness data as beam spot 1 moves, with the moving pitch of beam spot 1 as the Y axis, the data sampling points on data sampling line 2G as the Y axis, and the brightness data at each point as the Z axis. As a result, it can be seen that a three-dimensional data curve as shown in FIG. 9 is obtained. Therefore, the point showing the maximum data from this brightness distribution can be regarded as the center OG of beam spot 1, and once this center 0° is found, the centers of each of the R and B beams can be calculated using the same method. can do.

In this invention, each electron beam spot IR to I of R-H is
Each luminance data is measured at the same time for each moving pitch of B, and the center of each beam is calculated from each data.

Therefore, as shown in FIG.
At least three data sampling lines 2R to 2B are set corresponding to each of the phosphors 2R to 2B, and three electron beams are simultaneously excited in this state. Then,
As shown in FIG. 4, beam spots IR to IB corresponding to three beams are obtained.

For the beam spot 1R, only the luminance data emitted on the virtual data sampling line 2R provided on the phosphor R is stored in the image memory, and for the beam spot IG, the luminance data emitted on the virtual data sampling line 2R provided on the phosphor R is stored in the image memory. Only the luminance data emitted on the virtual data sampling line 2G provided on the phosphor B is stored in the image memory, and for beam spot IB, the luminance data emitted on the virtual data sampling line 2B provided on the phosphor B is stored in the image memory. only are stored in image memory.

Therefore, if the three beam spots IR to IB are simultaneously moved at a predetermined pitch in the direction of arrow a and the luminance data at each moving point is measured, each beam spot 1 to IR can be measured.
The three-dimensional brightness distribution of ~IB is shown in Figure 5,
From this, the center of each brightness distribution is calculated.

When the convergence is not achieved, the beam spots IR to IB arrive at different phosphor positions as shown in FIG. 4, for example, so that their centers (X, Y) are different. Therefore, three data sampling lines 2R
When beam spots IR to LB on the X and Y axes are plotted from the luminance data measured at 2B to 2B, the beam spots IR to LB are plotted as shown in FIG.

For example, the center oG of the electron beam IG (X,.

YG) as a reference, the beam spot I for this
R, IB (7) Center 0R1OB are each (X RIYR)
, (XB, YB), and the deviation rRG+rBG of the beam spots IR and 1B with respect to the center OG can be easily calculated from the data representing these centers. The center ○ serves as such a standard. It is possible to accurately judge whether convergence is good or bad based on the size of the deviation.

In this case, since the beam spots IR~IB are completely scanned from the beginning to the end on each data sampling line 2R~2B, the center OR of each beam spot IR~IB is
~08 is very accurate because the brightness data is calculated by sampling the entire shape of the beam pond, and therefore the convergence can be determined more accurately than the center 0RXO.

FIG. 1 is a system diagram showing an example for realizing the brightness distribution measurement shown in FIG. 3.

In FIG. 1, reference numeral 11 denotes a device to be measured for convergence measurement, which includes three beam spots IR to I.
A predetermined measurement pattern signal SC to simultaneously excite B
As a result, a dot pattern as shown in FIG. 3 is displayed on the picture tube surface.

The plurality of dots are imaged by a monochrome television camera 12, and the imaged output is converted into digital data by an A/D converter 13. Digital data is supplied to image memory 14 and stored in an area corresponding to each electron beam. The luminance data to be stored may be only the luminance data on the data sampling lines 2R to 2B, or may be R, G, and B luminance data of the entire beam spot, but this example shows the former case.

The brightness data of each electron beam stored in the image memory 14, that is, each data sampling line 2R~
Only the brightness data corresponding to R-B in 2B is supplied to a data processing device 15 constituted by a computer for each moving pitch of the beam spots IR to IB, and the center OR of each of the electron beams IR to IB described above is supplied. Day 0 is calculated, and a dot movement command signal is sent from the data processing device 15 each time data storage into the image memory 14 is completed.

In this example, the measurement pattern signal itself is sequentially moved by a predetermined pitch in the direction of arrow a, so the dot movement command signal is supplied to the synchronization generation circuit 16, and the dot movement command signal is synchronized with the dot movement command signal. pattern generator 1
7 operates and a measurement pattern signal SC is output.

FIG. 2 shows an example of a measurement pattern signal, and the measurement background signal SC is sequentially shifted by the dot movement pitch and output (A and B in the same figure). In the data processing device 15,
As shown in FIG. 6, the center points OR~OB of the electron beams IR~IB are calculated from the respective brightness data, and from the X and Y data that determine these center points oR~OB, the reference center point OG is calculated. Center point OR, Oa for
The deviations rRG and rse are calculated. That is, these deviations r y +'8 (y is calculated as follows.

Va=YR-YG ・・・・・・(1) HRG
==XRXQ ・・・・・・(2), °,
rya=row'RG+H'RG ・・・・・・(3)va
a = YG - YB ... - (4) H
se "Xs Xa --(5),', r
e(w=0)] T-gradation (6) The movement of the dot is not determined by shifting the horizontal position of the dot signal SC, but by determining the horizontal deflection relative to the receiver 11 to be measured. The signal may be shifted.

FIG. 10 shows an example of this, in which the data processing device 15
The D/A converter 21 is controlled by the dot movement signal sent from the dot movement signal to form a sawtooth horizontal deflection signal, which is supplied to the pattern generator 17 and also to the horizontal deflection circuit 22. Each time this dot movement command signal is supplied, the DC level superimposed on the horizontal deflection signal sent from the horizontal deflection circuit 22 is controlled.

As a result, even if the phases of the measurement pattern signals output from the pattern generator 17 are the same, the DC of the horizontal deflection signal
As a result of the sequential shift of the level, the dots on the picture tube surface are sequentially shifted to the left, so that the beam spots IR to IB can be moved at a predetermined pitch as in the case of FIG.

Since this configuration only requires sequentially changing a predetermined DC voltage to the horizontal deflection signal, the measuring device is simple and is therefore suitable for application to picture tube inspection lines and the like.

In addition, in the above example, three data sampling lines 2
Although the brightness data was measured by setting R to 2B, it is also possible to set multiple data sampling lines for each phosphor as shown in Fig. 11, and in this case, the brightness data The measurement time can be reduced accordingly.

Luminance data may be measured not only in the Y direction but also in the X direction. In this case, for example, the beam may be moved in the horizontal direction, then moved in the vertical direction, and the respective luminance data may be measured by the same operation as described above.

〔Effect of the invention〕

As explained above, according to the present invention, in the vertical direction corresponding to each of the R, G, and B phosphor stripes sequentially arranged at a predetermined pitch in the horizontal direction of the picture tube surface,
Set up at least three data sampling lines,
The R, G, and H measurement patterns are simultaneously moved horizontally at a predetermined pitch, and each of the R, G, and B measurement pattern regions in the vertical direction at each data sampling line is measured at each horizontal movement pitch. The luminance data of R,
The center points of each measurement pattern of G and B are calculated, and the convergence state is measured based on the data of these center points.

In this case, since the brightness data to be memorized is obtained for the entire area of the electron beam spot that crosses the data sampling line, the calculation of the beam center is accurate, and accordingly, other It has the characteristics of being able to accurately calculate the deviation of the beam center and accurately determining whether the convergence state is good or bad.

In addition, since the luminance data from at least three data sampling lines are measured simultaneously, the convergence measurement time can be significantly shortened, and the beam pattern sequentially shifts the phase of the measurement pattern signal by a predetermined pitch. Because of this, it is possible to accurately measure the convergence state of a portion of the corner of the screen, and the convergence of the entire screen can be easily and accurately measured.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of a convergence measuring device according to the present invention, FIG. 2 is a diagram showing an example of a dot signal,
Figure 3 is a diagram showing the relationship between the phosphor and the data sampling line, Figure 4 is a diagram showing the relationship between the data sampling line and the electron beam, and Figure 5 is a diagram showing the distribution of brightness data of the electron beam. , FIG. 6 is a diagram showing the shift of the center of the electron beam, FIG. 7 is a diagram similar to FIG. 4 used to explain this invention, FIG. 8 is its brightness distribution diagram, and FIG. 9 is a three-dimensional brightness diagram. FIG. 10 is a system diagram showing another example of the present invention; FIG. 11 is a diagram showing the relationship between the phosphor and data sampling line showing still another example of FIG. 3; FIG. 1
2 and 13 are diagrams for explaining conventional examples of convergence measurement of picture tubes, respectively. IR to IB are electron beam spots, R-B is phosphor, 2
R to 2B are data sampling lines, 11 is a receiver to be measured, 12 is a television camera, 14 is a memory for brightness data, 15 is a data processing device, and SC is a measurement pattern signal. Figure -7 Figure 8 Figure 3 A BC 8 Figure 12 Figure 11 Figure 13

Claims (1)

[Claims] At least three data sampling lines are provided in the vertical direction corresponding to each of the R, G, and B phosphor stripes sequentially arranged at a predetermined pitch in the horizontal direction of the picture tube surface. The R, G, and B measurement patterns are simultaneously moved at a predetermined pitch in the horizontal direction, and each measurement pattern area for R, G, and B is vertically moved at each data sampling line at each horizontal movement pitch. An image reception system that sequentially stores luminance data in each direction, calculates the center point of each R, G, and B measurement pattern based on these luminance data, and measures the convergence state based on the data at these center points. Tube convergence measuring device.