JPH04363840A - Extending type color selecting electrode - Google Patents

Abstract

PURPOSE:To provide an extending type color selecting electrode with less vibration and a short attenuating time to shorten the color purity reduction by the vibration of a grill line and the time thereof. CONSTITUTION:The length of a grill line 23 is set in such a manner that the part with a small tension added by a frame 1 is shorter than the part with a large tension so as to enhance resonance frequency. When the length of the grill line 23 in which the added tension is small is shortened to increase the resonance frequency, the amplitude at the time of resonance is reduced, and the attenuating time of vibration is shortened, so that the purity reducing time by an external vibration can be shortened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expandable color selection electrode for a color cathode ray tube.

0002

2. Description of the Related Art A stretched color selection electrode is a color selection electrode in which slits for transmitting electron beams are arranged in one direction, for example, in the vertical direction, facing the phosphor screen of a color cathode ray tube. A shadow grill is arranged so that electron beams corresponding to each color incident on the slit from different directions land on the phosphors of each color on the phosphor screen.

FIG. 9 is a front view of a conventional expanded color selection electrode.
FIG. 10 is a side view thereof. In the figure, reference numeral 21 denotes a shadow grill, and as shown in FIG. 9, a large number of slits 22 are formed in parallel in a thin metal plate, extending in one direction, for example, in the vertical direction, and having substantially the same length over the entire area. ,
A shadow grill 21 on which grill lines 23 are formed is stretched between the arm portions 1a and 1b of the frame 1.

As shown in FIG. 2, the frame 1 consists of arm portions 1c and 1d that support a pair of opposing frame pieces 1a and 1b, both of which are welded at welded portions 2a to 2d. Each of the pieces 1a and 1b has an L-shaped cross section, and a shadow grille 21 is welded and fixed to the end face thereof in an expanded state.

When the shadow grill 21 is stretched over the frame 1, the color selection electrode constructed as described above is attached to the arm portions 1 of the frame pieces 1a and 1b of the frame 1, as shown in FIG.
A load is applied in the direction of arrow F near the welding point with c and 1b.

[0006] The amount of deflection of the frame pieces 1a and 1b at this time is:
They approach each other in a distribution as shown in FIG. I'm trying to add tension to it. FIG. 12 is a distribution diagram of the tension applied to the grill wire 23.

[0007] Thereafter, the protruding portions of the frame pieces 1a and 1b are cut to obtain the expanded color selection electrodes shown in FIGS. 9 and 10.

[0008]

[Problems to be Solved by the Invention] In the conventional expandable color selection electrode, since the support points of the frame pieces 1a and 1b of the frame 1 are located near the Bessel point, the tension distribution applied to the grill wire 23 is as shown in FIG. As shown, the tension is greatest near the Bessel points of the frame pieces 1a and 1b, and the tension becomes weaker as it approaches the center and ends. When the tension of the grille wire 23 becomes weaker, the resonance frequency of the grille wire 23 becomes smaller, so the damping time of the vibration becomes longer and the amount of amplitude becomes larger.

[0009] This means that when this CRT is installed in an actual TV set, when the vibrations emitted from a vibration source such as a speaker match the resonance point of the grille wire 23, the grille wire 23 will sway greatly, causing fluorescent light. This means that a color shift phenomenon occurs on the surface, and it takes a long time to restore the original state.

In an actual example for a 23-inch CRT, the tension applied to each grill wire 23 is 192 g at the center.
It is 300g near the Bessel point and 243g at both ends,
The amount of this change is determined by the structure of the frame 1, the magnitude of the pressure F applied to the frame when the shadow grill is stretched, the pressure position, etc., and it is difficult to make it uniform over the entire surface of the shadow grill 21.

[0011] This invention was made in order to solve the above-mentioned problems, and the resonance frequency of the grill line is large over the entire surface of the shadow grill, so that vibrations can be damped in a short time and the amplitude can be reduced. The purpose is to obtain a stretched color-selecting electrode that can be used.

0012

[Means for Solving the Problems] In the expanded color sorting electrode according to the present invention, the length of the grille wire is made correspondingly shorter in areas where the tension applied to the grille wire is weaker than in areas where the tension is stronger. It is characterized by points.

[0013]

[Function] In the shadow grill of this invention, when vibration of the same energy is applied to the grill wire from the outside, the vibration damping time characteristic is proportional to the length of the grill wire. By shortening the length,
The vibration damping time can be shortened, and the amplitude can also be reduced.

[0014]

【Example】

Example 1. Below, a 23-inch CR to which this invention is applied
An embodiment of the expanded type color selection electrode for T will be described with reference to the drawings. Figure 3 shows the shadow grill 2 before being stretched over the frame 1.
1, a slit 22 with a width of 65 μm is formed in a thin metal plate with a thickness of 0.1 mm by chemical etching, and the length of the slit 22c in the center is 264 mm,
The length of the slit 22d near the welded part between the frame pieces 1a, 1b and the arm parts 1c, 1d is 330 mm, and the length of the slit 22e near the end of the frame is 297 mm. It is formed so that it becomes longer or shorter depending on the amount of tension applied to it.

FIG. 2 is a perspective view showing the structure of the frame 1. The frames 1a and 1b are L-shaped, and the dimensions of each part are such that g is 2.
0mm, h is 20mm, i is 5mm, L1 is 450mm
It is made of heat-resistant steel such as chrome-molybdenum steel. Arm parts 1c and 1d have a rectangular cross-sectional shape, and the dimensions of each part are: j is 15 mm, k is 15 mm, and L2 is 350 mm.
It is made of the same heat-resistant steel material as the frame piece 1a.

[0016] Near the vessel of frame 1, 100
Apply pressure in one direction of the opposing frame with a force F of kg to separate the frame pieces 1a,
1b is deformed by the amount of deflection shown in FIG. 12, and under this condition, the shadow grill 21 is stretched in the same manner as before, and the protruding portions around it are removed, and the color sorting shown in FIG. 1 is performed. Get the electrodes.

In this case, the tension portion applied to the grill wire 23 is the same as in the conventional example shown in FIG.
As shown in FIG. 1, the length of grill wire 23 is 20% shorter at the center and 10% shorter at the ends compared to the conventional product. Compared to the conventional example, the natural frequency in the center part was 300Hz instead of 240Hz.
HZ, what was 270HZ at the end is now 300H
Z respectively rose.

As a result, when vibrations of the same energy are applied to the shadow grill, the vibration damping characteristics are improved and the amplitude is reduced, so that on the CRT screen,
It has been possible to shorten the time during which grill wire vibrations are observed, and the maximum amplitude has also been reduced.

Example 2. In order to reduce the production cost of the frame 1, as shown in FIG.
As shown in Figure 7, the tension is lowest at the center and highest at the ends, so the resonant frequency distribution is as shown in Figure 8.
As shown in , the frequency at the center becomes lower and the decay time becomes longer, which poses a practical problem.

In order to improve this problem, as shown in FIG. 6, the grill line 2 is
The length of 3 was shortened. As a result, as shown in FIG. 8, the vibration characteristics were improved to the point that they did not pose any practical problems.

[0021]

As described above, according to the present invention, the length of the grill wire is adjusted according to the magnitude of the tension applied to the grill wire to increase the natural frequency of the grill wire. The amount of amplitude can be reduced. Therefore, even if the grille wires vibrate due to vibrations applied from the outside, it is possible to obtain an expanded color selection electrode that causes less color shift on the CRT screen and disappears in a short time.

[Brief explanation of drawings]

FIG. 1 is a front view of a color selection electrode according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a frame of this embodiment.

FIG. 3 is a plan view of the shadow grill before being stretched over the frame of this embodiment.

FIG. 4 is a distribution diagram showing the natural frequencies of the grill wires of the present embodiment and the conventional example.

FIG. 5 is a perspective view showing the structure of a cost-reduced frame according to a second embodiment of the present invention.

FIG. 6 is a plan view of a shadow grill before being stretched over a frame according to a second embodiment of the present invention.

7 is a diagram showing the distribution of tension applied to the grill line of the shadow grill stretched over the frame shown in FIG. 5; FIG.

FIG. 8 is a diagram showing vibration characteristic distributions of grill lines in this embodiment and a conventional example.

FIG. 9 is a front view of a conventional expanded color selection electrode.

FIG. 10 is a side view of a conventional expanded color selection electrode.

11 is a diagram showing the amount of deflection of the arm portion of the frame caused by the force F applied when the shadow grill is stretched on the frame shown in FIG. 2; FIG.

12 is a diagram showing the distribution of tension applied to the grill line of the shadow grill stretched over the frame shown in FIG. 2; FIG.

[Explanation of symbols]

1 Frame 21 Shadow grill 22 Slit 23 Grill line

Claims (1)

[Claims] [Claim 1] A stretched color sorting electrode in which a shadow grill, in which a thin metal plate is selectively etched to form grill lines extending in one direction, is stretched and fixed to a frame, in which the length of the grill lines is fixed. An expanded color-selecting electrode characterized in that the length is short where the applied tension is small and long where the applied tension is large.