KR970010035B1 - Panel for color picture tube - Google Patents

Abstract

In the panel for a color cathode-ray tube, a black strife spaced-apart width of a panel(1) coated with a fluorescence substance light-emitted by a electric beam is reduced from a center of the panel to a predetermined position which extends from a center of a short axis to an end of the long axis, and is increased from the predetermined position to an end of the long axis.

Description

Panel for color cathode ray tube

1 is a schematic structural diagram of a general color cathode ray tube.

FIG. 2 is a reference diagram illustrating the ming phenomenon of a shadow mask in FIG. 1.

3 is a reference diagram showing a state in which an electron beam is landing on the side of the fluorescent surface BM stripe (aka, black stripe) of FIG.

FIG. 4 is a reference diagram when the landing is missed due to the shadow mask side phenomena in FIG.

4 (a) is a reference diagram for explaining the adjustment state of the BM stripe separation width.

5 is an enlarged reference view of a part of the fluorescent surface side BM stripe in FIG.

6 is a reference diagram extracting the main portion of the portion where the mis-landing phenomenon caused by the dominant phenomenon is maximized on the fluorescent surface BM stripe side of FIG.

FIG. 6 (a) is a reference diagram showing the increase / decrease position of the BM stripe side separation width on the full screen of FIG.

7 is a reference diagram of a state in which the magnitude of the BM stripe separation width is changed in the X-X axis direction about the Y-Y axis of the rectangular coordinates in FIG.

FIG. 8 is another example of FIG.

9 is a chart showing the magnitude change of the fluorescent surface BM stripe separation width according to the present invention.

* Explanation of symbols for main parts of the drawings

1 panel, 1a fluorescent surface A: oblique portion

a, b, c: separation width of BM stripe

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a panel of a color cathode ray tube, and in particular, a dominant phenomenon of a shadow mask in which the size of the fluorescent black stripe separation width considering the dominant phenomenon of the shadow mask of the color cathode ray tube proceeds from the central portion to the side side thereof. According to the mis-landing compensation conditions according to the present invention relates to a panel that can be satisfactorily improved by selectively varying the shape of the BM (black matrix) stripe separation width.

The schematic structure of this kind of colored cathode ray tube is shown in FIG.

In this case, the fluorescent mask 1a applied to the inside of the panel 10 and the shadow mask 5 are fixed to the stud 6 and the support spring 7.

The beam emitted from the electron gun collides with the fluorescent surface 1a via the balls of the shadow mask 5 to reproduce the color image.

In addition, about 20% of the beam emitted from the electron gun passes through the shadow mask side hole and 80% hits the shadow mask wall surface to heat it.

Therefore, at this time, the shadow mask 5 is inflated from the normal state 5A to the dome state 5B by thermal expansion, as shown in FIG. 2, and thus the position where the electron beam touches the fluorescent surface is normal as in FIG. As a result, the mislanding phenomenon as shown in FIG. 4 occurs.

The mislanding phenomenon as described above has been a problem since it lowers the color purity.

On the other hand, the mis-landing caused by the dominant phenomenon of the shadow mask 5 is maximized at the side diagonal portion A side of the fluorescent screen as shown in Fig. 6, and the amount decreases toward the center of the screen.

In addition, as a countermeasure for minimizing the mislanding caused by the dominant phenomenon, a bimetal is attached between the studs 6 and the support springs 7 to lift the shadow mask 5, thereby reducing the mislanding phenomenon as shown in FIG. As shown in Figs. 7 and 8, the BM stripe (black with good light absorption around the R, G, and B phosphors in the fluorescent plane) is gradually obtained in both directions of the X axis about the center Y axis of the two-dimensional panel as shown in Figs. Means for primarily reducing the size of the band gap formed by applying the material have been devised.

However, in the former technique described above, the maximum masking of the shadow mask 5 occurred, so that the bimetal was designed to act so that the dominance of the dominant beam was lacking. In the latter technique, the peripheral width of the fluorescent surface BM stripe was There is a problem that the relative width is smaller than the center width, causing the luminance deterioration of the periphery thereof.

The present invention has been proposed to improve the above-described problems, and the size of the BM stripe separation width corresponding to the middle portion of the peripheral portion is smaller than the BM stripe separation width portion of the screen weight, and the BM stripe separation in the X-axis direction The width is characterized by a parabolic structure and a shadow mask having a configuration in which the Y-axis direction changes linearly.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

That is, Figure 9 is a reference diagram showing the size, arrangement and shape of the BM stripe separation width according to the present invention.

Here, the array of BM stripes formed as shown in FIG. 5 is 13A, 13B, and 13C, and the separation widths are represented by 13a, 13b, and 13c, and the size of the BM stripe separation widths 13a, 13b, and 13c is the shadow mask 5 The three electron beams that pass through) are sized to easily emit only blue, green, and red phosphor stripes or dots.

That is, the size of the BM stripe separation width 13a, 13b, 13c decreases from the center of the panel to a predetermined (1/2) point of the line connecting the short axis center and the long axis end thereof, and the long axis end at the predetermined (1/2) point. Until it becomes an increasing form.

In this case, a predetermined (1/2) point of the line connecting the short axis center and the long axis end is reduced by the first (c) or second (c) or higher order gradient in the X-axis (or Y-axis) direction of the rectangular coordinates. From the predetermined (1/2) point to the end of the long axis, the BM stripe spacing increases in the X-axis (or Y-axis) direction of the Cartesian coordinate with the first (c) or second (b) or higher order gradient. The shape is preferably, and the inversion section of the BM stripe spacing size may be provided within 2 / 4-3 / 4 of the line connecting the short axis center and the long axis end of the panel.

Here, the size of the screen center BM stripe separation width and the periphery BM stripe separation width, which are diagonal lines A of FIG. 6, which are liable to greatly reduce the color purity due to the dominant phenomenon of the shadow mask 5, are formed in the X-axis. W is a parabolic structure of W = aX2 + bX + c when the spacing width in the direction is W, and the BM stripe spacing width is changed in the first direction as shown in FIG. .

That is, as shown in FIG. 6 (a), the BM stripe separation width in the CRT is larger in the periphery than the center of the screen, and the maximum doming is performed at the 1/4 or 3/4 point of the screen width. Therefore, the color reproducibility can be improved by reducing the BM stripe spacing at the point where the doming is the first.

That is, the BM stripe separation width is decreased from the point (a) to the end point on the long axis or the diagonal axis of the screen from the point (a) to the point (a) which is the maximum dominant point based on the center of the screen. At this time, in decreasing or increasing the BM stripe spacing, an increase or decrease of the BM stripe spacing is adjusted by using a slope of an appropriate first-order function, second-order function, or higher-order function.

The present invention of such a configuration is as follows.

That is, when the shadow mask 5 causes a dominant shape, the resulting color purity decreases at the maximum mis-landing (or degree) at the oblique portion A, which is halfway between the center and the periphery of the screen as shown in FIGS. 6 and 6 (a). The amount of dimming) is usually about 20 占 퐉 when the 20-inch type is used.

Therefore, the fluorescent surface BM stripe separation width according to the present invention is set to 10-15 μm smaller on the oblique side than the conventional one so that the electron beam width is 15-20 μm smaller, so that the mislanding phenomenon as shown in FIG. 4 can be eliminated. do.

In other words, when the mislanding is performed as shown in FIG. 4, it is difficult to reproduce the desired color by emitting a phosphor of another color, so that the BM stripe separation width is set to 10-15 μm so that the BM strip is formed relatively thick to prevent mislanding. In addition, color reproducibility is improved by emitting a desired color.

Referring to FIG. 4 (a), in the case of (a), the R beam emits the phosphors of R and B at the same time, but by setting the BM stripe spacing small, only the phosphor of R is emitted as shown in (b) and the color is emitted. Reproducibility will be better.

In addition, since the maximum doming phenomenon occurs in the vicinity of a1, which is on the X-axis of FIG. 6, and the domming amount is reduced in the shape of a long ellipse on the basis of a1, the BM stripe separation width of the present invention is directed toward the Y axis. In the form of increasing the peripheral brightness can be increased than in the conventional case.

As described above, the fluorescent surface BM stripe structure for color cathode ray tube according to the present invention takes the size of the BM stripe space width appropriately selectively in the area where the dominant amount of the shadow mask is generated to the maximum, thereby preventing the color purity from deteriorating and providing the peripheral luminance with good quality. There are beneficial features that can be done.

Claims (2)

The black stripe separation width of the panel 1 coated with the phosphor emitting by the electron beam decreases from the center of the panel to a predetermined point of the line connecting the short axis center and the long axis end with a slope of the first, second, or higher order function, Color cathode ray tube panel, characterized in that configured to increase as the slope of the first, second or higher order function from the predetermined point to the end of the long axis. The panel for color cathode ray tubes according to claim 1, wherein the panel is provided with an inversion section having a black stripe separation width within 2 / 4-3 / 4 connecting the short axis center and the long axis end of the panel.

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