JPH0646543B2 - How to measure the convergence of a picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a picture tube convergence measuring apparatus suitable for application to various image display apparatuses.

[Outline of Invention]

The present invention relates to a convergence measuring device for a picture tube which is suitable for application to various image display devices, and in particular, R, G, B beam spots passing through an electron beam arrival position determining electrode are sequentially arranged at a predetermined pitch in the horizontal scanning direction. By calculating the center point of each measurement pattern of R, G, and B from the brightness data in all the shapes of the beam spot obtained when the beam spot is moved, and measuring the convergence state based on the data of these center points, R , G, B center points can be accurately measured, whereby the quality of convergence can be easily and surely determined.

[Conventional technology]

Convergence measurement for measuring the concentration of electron beams corresponding to each of the R, G, and B phosphors in the color picture tube may be conducted visually or with a measuring device. It is better to use the device. An example of using a measuring device is disclosed in JP-A-59-7.
It is already known from Japanese Patent No. 4781.

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

When 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) is displayed, even though the measurement pattern of the same area is displayed. It changes with respect to the true center of gravity position O. Since this deviation causes a measurement error, the above-mentioned prior art employs the following means in order to avoid this measurement error.

That is, focusing on the fact that the measured value of the center of gravity changes in a trigonometric function with respect to the positional relationship between the measurement pattern and the fluorescent body,
When the measurement pattern is imaged at an arbitrary positional relationship, for example, T ₁ in FIG. 13, the measurement pattern is generated at a position (1/2 of the array pitch of the fluorescent bodies) T ₂ that is symmetrical to this positional relationship. The pattern is imaged, and the average value of each pattern is obtained to offset the error in the measurement value and improve the measurement accuracy.

[Problems to be solved by the invention]

By the way, even such a conventional convergence measuring device cannot accurately obtain the beam concentration.

That is, the above-described measuring device cancels an error caused by the mutual relationship between the beam spot position and the position of the fluorescent body by moving the dot signal on the CRT by 1/2 pitch. Since the position of the center of gravity is calculated based on the image information of the beam spot shape that is missing in the electron beam arrival position determination electrode as it is,
This is because there is always an error in the calculation of the center of gravity of the beam spot, and the accumulated error appears as an error in convergence measurement.

Therefore, the present invention solves such a conventional problem, and enables to accurately calculate the beam center even when the beam spot shape is deformed by the electron beam arrival position determining electrode. It improves the accuracy of convergence measurement.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, as shown in FIGS. 1 to 4, Rs are sequentially arranged at a predetermined pitch in the horizontal direction of the picture tube surface. , G, B corresponding to the respective fluorescent stripes, at least three data sampling lines are set in the vertical direction of each stripe, and the R, G, B measurement patterns are simultaneously moved in the horizontal direction at a predetermined pitch. Then, the respective luminance data in the vertical direction in each measurement pattern region regarding R, G, B in each of the data sampling lines are sequentially stored for each horizontal movement pitch. Luminance data measurement is performed until the beam has completely passed through the sampling line.

The center point of each measurement pattern of R, G, and B is calculated based on these brightness data, and the state of convergence is measured based on the data of these center points.

[Action]

According to this configuration, the center of the beam, that is, the center of gravity of the beam is calculated from all the luminance data that cross the sampling line, so that the center of gravity of each of the R, G, and B beams can be accurately calculated. 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, so that the accuracy of convergence measurement can be improved.

〔Example〕

FIG. 1 is a system diagram showing an example of a picture tube convergence measuring method 10 according to the present invention.
The measurement principle of the present invention will be described first with reference to FIG.

In FIG. 7A, R, G, and B represent stripe-shaped phosphors arranged in a horizontal direction with a predetermined pitch, and any of these phosphors, G phosphors in this example, are shown. The data sampling line 2G is virtually set at the corresponding position. A plurality of sampling points are set in 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.

When the electron beam spot 1 that has passed through the electron beam arrival position determining electrode reaches the fluorescent body, if only the G fluorescent body is focused, it emits light as shown by the hatched lines, and the electron beam spot 1 is emitted in the direction of arrow a ( Data sampling line 2G can be
Emitting region in above, the increased toward the beam center O _G, gradually its area decreases if Sugire center.

From this fact, when the luminance distribution on the data sampling line 2G is measured, a unimodal data curve as shown in FIG. 8 is obtained. In this figure, K is beam spot 1
If the light emitting area of the beam does not lie on the data sampling line 2G and K becomes larger, and the beam spot 1 moves to the left as K increases, the luminance distribution becomes The maximum is at the center of the and the minimum is around it.

The movement pitch of the beam spot 1 is taken as the X axis, the data sampling points on the data sampling line 2G are taken as the Y axis, and the luminance data at each point is taken as the Z axis, and the distribution of the luminance data accompanying the movement of the beam spot 1 is measured. Then, it is understood that a three-dimensional data curve as shown in FIG. 9 is obtained. Therefore, it is possible to point indicating the maximum data from the luminance distribution regarded as the center O _G of the beam spot 1,
As long the center O _G is determined, it is possible to respectively calculate the center of each beam of the R and B in the same unit.

In the present invention, the R-B electron beam spots 1R-1
The respective brightness data are simultaneously measured for each moving pitch of B, and the center of each beam is calculated from the respective data.

Therefore, as shown in FIG.
At least three data sampling lines 2R to 2B are set corresponding to the respective G and B phosphors, and in this state, three electron beams are excited simultaneously. Then, as shown in FIG. 4, beam spots 1R to 1B corresponding to the three beams are obtained.

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

Therefore, by measuring the brightness data at each moving point while moving the three beam spots 1R to 1B at the same time in the direction of arrow a at a predetermined pitch,
The three-dimensional luminance distribution of 1B is as shown in FIG. 5, and the center of each luminance distribution is calculated from this.

When the convergence is not achieved, for example, the beam spots 1R to 1B reach different positions of the fluorescent bodies as shown in FIG. 4, so that the respective centers (X, Y) are different. Therefore, 3 data sampling lines 2R
When the beam spots 1R to 1B on the X and Y axes are plotted from the luminance data measured at .about.2B, the results are shown in FIG.

Then, for example, the center O _G (X _G ,
Y _G ), the beam spot 1
R, 1B of the center _O R, _{O B} are each _{(X R, Y R),} (X
_B , Y _B ), the deviations r _RG , r _BG of the beam spots 1R, 1B with respect to the center O _G can be easily calculated from the data representing these centers. The magnitude of the deviation from the center O _G to be such a reference, it accurately determine the quality of Compur Jens.

In this case, the beam spot 1R~1B is fully scanned over the data sampling line 2R~2B from beginning to end, the center _{O R} of each beam spot 1R~1B
Since ~ O _B luminance data by sampling the entire shape of the beam spot is calculated, it is very accurate, therefore, it is possible to obtain the convergence from these center O _R ~ O _B accurately.

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

In FIG. 1, reference numeral 11 denotes a device to be measured for convergence measurement, which has three beam spots 1R to 1R.
Predetermined measurement pattern signal SC for exciting B simultaneously
Is supplied, whereby a dot pattern as shown in FIG. 3 is displayed on the picture tube surface.

The plurality of dots are imaged by the monochrome television camera 12, and the imaged output is converted into digital data by the A / D converter 13. The digital data is supplied to the image memory 14 and stored in the 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 the 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 luminance data respectively corresponding to R~B within each movement pitch of the beam spot 1R~1B in 2B, is supplied to the data processing apparatus 15 which is constituted by a computer, the center O _G of the electron beam 1R~1B described above with ~ O _B is calculated, from this data processor 15, each time the data store completion of the image memory 14, the dot move command signal is sent.

In this example, the measurement pattern signal itself is sequentially moved in the direction of the arrow a by a predetermined pitch. Therefore, the dot movement command signal is supplied to the synchronization generation circuit 16 and is synchronized with the dot movement command signal. The pattern generator 17 operates to output the measurement pattern signal SC.

FIG. 2 shows an example of the measurement pattern signal, and the measurement pattern 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,
Along with its center point from the luminance data of respective _O R ~ O _B it is calculated in the electron beam 1R~1B as shown in FIG. 6, X, from the Y data to determine these center points _O R ~ O _B, criteria and center point _O R with respect to the center point _{O G} consisting, displacement r _RG of _{O B,} r _BG is calculated. That is, these deviations r _RG and r _BG are calculated as follows.

The movement of the dot is not obtained by shifting the position of the dot signal SC in the horizontal direction, but the receiver 1 for measurement is used.
The horizontal deflection signal for 1 may be shifted.

FIG. 10 shows an example of the data processing device 15.
The D / A converter 21 is controlled by the dot movement signal sent from the device to form a sawtooth-shaped horizontal deflection signal, which is supplied to the pattern generator 17 and the horizontal deflection circuit 22. Each time the 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 phase of the measurement pattern signal output from the pattern generator 17 is the same, the DC of the horizontal deflection signal is
As a result of the level being sequentially shifted, the dots on the surface of the picture tube are sequentially shifted to the left, so that the beam spots 1R to 1B can be moved at a predetermined pitch as in the case of FIG.

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

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 a plurality of data sampling lines for each phosphor as shown in FIG. The measurement time can be reduced by that much.

The 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 and then in the vertical direction, and the respective brightness data may be measured by the same operation as described above.

〔The invention's effect〕

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

In this case, the brightness data to be stored is obtained for the entire area of the electron beam spot that crosses the data sampling line, and therefore the calculation of the beam center becomes accurate, and accordingly, the other beam center for the reference beam center is calculated. The deviation of the beam center can be accurately calculated, and the quality of the convergence state can be accurately judged.

Further, since the brightness data from at least three data sampling lines are measured at the same time, 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. Therefore, the convergence state of the corner portion of the screen can be accurately measured, and the convergence of the entire screen can be easily and accurately measured.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of the convergence measuring device according to the present invention, and FIG. 2 is a diagram showing an example of a dot signal.
FIG. 3 is a diagram showing the relationship between the fluorescent substance and the data sampling line, FIG. 4 is a diagram showing the relationship between the data sampling line and the electron beam, and FIG. 5 is a diagram showing the distribution state of the brightness data of the electron beam. FIG. 6 is a diagram showing the deviation of the center of the electron beam, FIG. 7 is a diagram similar to FIG. 4 used to explain the present invention, FIG. 8 is its luminance distribution diagram, and FIG. 9 is three-dimensional luminance. FIG. 10 is a diagram showing a distribution state, FIG. 10 is a system diagram showing another example of the present invention, and FIG. 11 is a diagram showing still another example of FIG. 3, showing the relationship between fluorescent substances and data sampling lines. 1
2 and 13 are diagrams for explaining a conventional example of the convergence measurement of the picture tube, respectively. 1R to 1B are electron beam spots, RB are fluorescent bodies, 2
R to 2B are data sampling lines, 11 is a receiver for measurement, 12 is a television camera, 14 is a memory of luminance data, 15 is a data processing device, and SC is a measurement pattern signal.

Claims (1)

[Claims] 1. An image of a tube surface of a picture tube on which respective R, G, B beam spots are projected is imaged, and R, G, which are sequentially arranged at a predetermined pitch in the horizontal direction on the imaged screen. Corresponding to at least 3 of each fluorescent stripe of B,
Data sampling lines each having a plurality of sampling points are set at predetermined intervals in the vertical direction, and the R, G, and B beam spots are simultaneously moved in the horizontal direction at a predetermined movement pitch, Luminance data at the plurality of sampling points of the R, G, and B beam spots on the data sampling lines at each of the moving pitches are sequentially stored, and based on these luminance data, the R, G, B The method for measuring the convergence of a picture tube, in which the center points of the respective beam spots are calculated and the state of convergence is measured based on the data of these center points.