JPS63119139A - Shadow mask - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shadow mask, and in particular, expands the opening surface of a slot to change the color [!] of the periphery of the screen. This invention relates to a shadow mask with improved intensity and brightness.

[Prior art and its problems]

In general, a shadow mask is formed by arranging circular or slot-shaped movie holes with a diameter of 0.2 to 0.25 seconds at intervals of 0.56 to 0.75Nn over the entire surface of a 0.15m thick iron plate. has been done.

This J: Una shadow mask [:1, Inside the color cathode ray tube, the center of deflection of the electron beam and the straight line that extends each beam hole coincide with the center of the phosphor corresponding to each beam hole. It is used by placing it in

As is already known, when the electron beam emitted from the electron gun passes through each beam hole in turn, the shadow mask absorbs energy and causes doming.
ing).

This doming causes mislanding and has a negative effect on image quality. In particular, this effect is more pronounced at the periphery of the screen than at the center.

The reason for this is that the ribs that the electron movie scans from the peripheral beam aperture are deflected by the deflection coil, so that the scanning direction is not parallel to the axis of the beam aperture but intersects it, so the electron beam is This is because it easily interferes with the inner wall.

The above-mentioned problems can be somewhat improved by changing the arrangement pattern of the beam holes and the distribution pattern of the phosphors, or by decreasing the aperture area of the beam holes as it goes toward the periphery.

This J: Eel method shadow mask is US Patent No. 3.7
This method has been proposed in the specification of No. 05,322, the specification of No. 4,139°797, etc.

However, the above method cannot solve the problem of brightness at the periphery of the screen.

In a color television, the reason why the brightness decreases in the peripheral area is because the electron beam passing through the peripheral beam aperture is significantly smaller than that in the central area.

Therefore, as a solution to this problem, it is desirable to widen the frontage area of the peripheral beam hole to balance the brightness.

On the other hand, in a shadow mask, the arrangement interval of the beam holes is related to the color purity and directly affects the curvature strength of the mask body, so the deformation of the beam holes is considerably limited.

For the reasons mentioned above, conventional beam hole improvements have been made by changing the aperture cross-sectional shapes of both U and J5 into sloped holes or parabolic cross-sectional holes, so that when the electron beam passes through the beam hole, the inner wall This is to the extent that no interference occurs.

[Purpose of the invention]

An object of the present invention is to provide a shadow mask that can obtain uniform brightness over the entire screen.Another object of the present invention is to provide a shadow mask that can provide uniform brightness over the entire screen. It is an object of the present invention to provide a shadow mask in which the frontage area of the beam hole on the peripheral side is increased without causing any problems. Still another object of the present invention is to provide a shadow mask in which the aperture area is relatively increased toward the outer periphery of the central beam hole.

(Summary of the Invention) The shadow mask of the present invention has the following features: the distance between the central slot and the peripheral side slot on the outer periphery of A; A proportional spacing Δ is given to the upper and lower ends of the outward side of each peripheral slot by a function related to the internal deviation angle, so that each peripheral slot has an area increase α proportional to the function. , the color of the periphery of the screen IIl! It is characterized by improved brightness and brightness.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 8 show the dimensions of an embodiment in which the present invention is applied to a slot-shaped shadow mask.

In FIGS. 1 and 2, reference numeral 1 indicates a conventional central slot located at the center of the mask body 2. As shown in FIG. Centering around this central slot 1, peripheral slots 3 are arranged around the outer periphery in the same pattern as a typical four-slot 1 shadow mask. As shown in FIG. 2, this peripheral slot 3 increases the area far from the center thrower ~1, that is, the upper and lower corners of the outward side, to proportional intervals, and holds the area increase α. It is formed to do so. The area increase α is determined by the proportional interval Δ, and the proportional interval is determined by a function f(x) related to the distance between the peripheral slot 3 and the central slot 1 and the deflection angle of the electron beam. It is given with the value obtained by .

In other words, the deflection angle of the electron beam in a color cathode ray tube is 1
5 degrees, 30 degrees, 45 degrees, 60 degrees, and 75 degrees (). In this case, the amount of reduction in the electron beam passing through the peripheral slot 3 within each deflection angle range is:
The distance from the center to the slot and the deflection angle are expressed by a function f(x).

This function f(x) can be obtained from experimental measurements for each deflection angle.

FIG. 3 is a graph showing changes in the proportional spacing Δ of the peripheral slots 3 within the range of a deflection angle of 15 degrees, and shows a function f (x)−
0,49285714,X10-'x-1-0.119
04775 shows a straight line determined by J:.

Similarly, FIG. 4 is a graph showing changes in the proportional spacing Δ of peripheral slots 3 located within a deflection angle of 30 degrees, and the function f (X) = 0.598214.31X10-'x
A straight line determined by 10.17857211X10-1 is shown.

FIG. 5 is a graph showing changes in the proportional spacing Δ of peripheral slots 3 located within a deflection angle of 45 degrees, and the function f (X) = 0.6124997X10-1x1-
It is shown as a straight line determined by 0.99999927X10'.

- Figures 6 and 7 each have a deflection angle of 60 degrees.
Proportional spacing of peripheral slots 3 located within a range of 5 degrees △
This is a graph showing changes in the function f (x) = 0.62
500000x10-1x+0.35714421x1
0-' and the functions f(X)-〇, 59999999X10'x, respectively.

The values of each proportional interval Δ obtained in the following manner correspond to the upper half or the lower half of the peripheral slot 3, so this value is applied to the peripheral slot 3. If the combinations are divided into 3 to 3 according to the earthwork target, it becomes the J, U/I pattern shown in Fig. 1.

In the shadow mask of the present invention described above, the area increase α is (J
In spite of this, a predetermined horizontal interval C and vertical interval C2 that does not affect the curvature strength of the mask body 2 or the color purity of both sides is maintained. Even if a part of the qi-direct interval C21 is eroded by the area increase α to form a small interval part 02', this extent will not cause any practical problems.

In the present invention, the arrangement of thrower 1- is conventional) A1-
This can be easily achieved by edging, and in this case, the cross-sectional shape of the slot can be made into a so-called uneven cross-sectional hole shape, and a good effect can be obtained.

Figure 8 shows an example of an electron beam landing on a phosphor on the peripheral side of the screen. The electron beam reaches a part of -C
It shows that there is no.

On the other hand, the dotted line part in the drawing shows an increase in the amount of beam landing corresponding to the area increase α of the shadow mass according to the present invention,
It can be seen that the electron beam reaches the corner in 4 minutes.

〔Effect of the invention〕

As explained above, in the shadow mask of the present invention, since it is possible for the electron beam of the same tIi as the center side to land even at the periphery of both sides, uniform brightness can be obtained even at the periphery of the screen. It will be done. Therefore, it is possible to produce a shadow mask product with high definition on both sides. Also,
Despite expanding the slot opening, it has the advantage of not affecting the curvature strength or color purity of the mask body at all, and does not require any special manufacturing steps, making production easy and cost-effective. This effect is achieved.

[Brief explanation of the drawing]

1 to 8 show an embodiment of the shadow mask of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a diagram showing the arrangement pattern of slots, and FIGS. 3 to 7 are views of the shadow mask. , the proportional interval Δ varies with respect to the function related to the electron beam deflection angle of the center slot and the peripheral slot 8-I foot and the corresponding peripheral slot, each deflection angle is 15 degrees, 30 degrees, 45 degrees,
FIG. 8 is a drawing showing an example of beam landing on a phosphor using a conventional shadow mask and a shadow mask of the present invention. 1... Center side slot, 2... Mask body, 3...
Peripheral side [1 piece 1 ~. Applicant's agent Shunsuke Naka IU; t3 figure mm ・: Moe Iken
Distance -: Theoretical value (30°) mm ・: 6 to Sagimaki
Distance -: Theoretical value (Fig. 5 mm) Distance・: Pulling value m: Filling f mm・: ηExperiment
Distance 4-: Theoretical value mm Distance distance-2 Stride value m: Theoretical value 78

Claims (1)

[Claims] A proportional spacing is given to the upper and lower ends of the outward side of each peripheral slot by a function related to the distance between the central slot and the peripheral slots on its outer periphery and the deflection angle of the electron beam with respect to each peripheral slot. , a shadow mask configured such that each peripheral slot has an area increase proportional to the function.