KR20040009715A - A Flat Cathode Ray Tube - Google Patents

Abstract

The present invention is a planar cathode ray tube including a panel having a curvature on the inner surface and a shadow mask applied to the tension, improving the representative curvature and thickness of the effective surface of the panel to improve the explosion-proof characteristics and to reduce the luminance according to the curvature configuration of the panel, It aims at solving the problem of the increase of breakage rate.

In order to achieve the above object, the present invention has a relationship between the horizontal axis, the vertical axis, and the representative curvatures Rh, Rv, and Rd of the inner surface of the panel effective surface, and Rh≤Rv≤Rd, and the relationship between the diagonal thickness Td and the center thickness Tc is Td / Tc≤. 1.35, preferably, the relationship between the short side thickness Th and the center thickness Tc is 1.0 <Th / Tc <1.4 and the long side thickness Tv and the center thickness Tc are 1.0 <Tv / Tc <1.4. to provide.

Description

Flat Cathode Ray Tube

The present invention relates to a flat cathode ray tube including a panel having a curvature on the inner surface and a mask to which tension is applied, the horizontal curvature, the vertical axis, and the diagonal representative curvatures Rh, Rv, and Rd of the inner surface of the panel effective surface, and the diagonal thickness Td and the center thickness Tc. , The short-side thickness Th, and the long-side thickness Tv.

In general, as shown in FIG. 1, a cathode ray tube combines a front glass called a panel 1 and a rear glass called a cone-shaped funnel 2 sealed to the panel to form a tube. Fluorescent surface 4, which plays a predetermined light emitting role, electron gun 6, which emits an electron beam that emits a fluorescent surface, shadow mask 3, which selects colors to emit a predetermined phosphor, and cathode ray tube during operation Inner shield (9) that serves as a shield to be less affected by the system, a frame assembly (7) for supporting the shadow mask, a spring holder (14), a spring (8) for coupling the frame assembly to the panel And a subframe 13 for applying tension to the shadow mask.

The operation of the cathode ray tube causes the electron beam generated from the electron gun 6 embedded in the neck of the funnel 2 to strike the fluorescent surface 4 inside the panel 1 by the voltage applied to the cathode ray tube. Before reaching the fluorescent surface, the deflection yoke 5 is deflected up and down and left and right to display a screen. In addition, the correction magnet 10 of 2, 4, 6 poles to correct the trajectory so that the electron beam strikes a predetermined phosphor accurately serves to prevent poor color purity.

As shown in FIG. 2, the frame assembly has a mask having a grille or a stripe-shaped hole attached with a tensile force in the vertical direction. The vertical curvature of the mask has a straight curvature and a convex curvature in the horizontal direction. Have

3A and 3B show a plan view and a side view of the cathode ray tube panel, respectively. The panel of the cathode ray tube is formed in the shape of a rectangle having an inner curvature so that the array of electron beams can be precisely matched to the curvature in the vertical and horizontal directions of the shadow mask. The panel includes an effective surface portion 15 to which phosphor is coated, a short side portion 16 formed in the vertical direction at both ends of the horizontal axis, a long side portion 17 formed in the horizontal direction at both ends of the vertical axis, and a corner portion forming both ends of the diagonal axis. It consists of 18 and the said three part consists of the scud 19 bent in the tube-axis direction at the edge of the effective surface.

4 shows the effective surface shape of a flat cathode ray tube panel. Typically, the radius of curvature of the outer surface is 50,000 to 100,000 R, which is almost flat when visually observed. The inner surface is aspheric. The inner curvature can be represented by the representative curvature of the horizontal axis is Rh, the representative curvature of the vertical axis is Rv, and the representative curvature of the diagonal is Rd. The inner curvature of the conventional panel is Rh≤Rd≤Rv, or Rv≤Rd≤Rh. Form. The relationship between the center thickness Tc, the long side thickness Tv, the short side thickness Th, and the diagonal thickness Td is obtained when the shadow mask is a tension type.

1) Tv / Td = 0.84 ~ 0.85,

2) Th / Td = 0.94 ~ 0.98,

3) Td / Tc = 1.2 ~ 1.3,

4) Tv / Tc = 1.0 ~ 1.1,

5) Th / Tc = 1.2 ~ 1.3

In the case of a form type,

1) Tv / Td = 0.75 ~ 0.99,

2) Th / Td = 0.75 ~ 0.85,

3) Td / Tc = 1.7 ~ 2.0,

4) Tv / Tc = 1.4 ~ 2.0,

5) Th / Tc = 1.4 ~ 1.6.

5 is a diagram showing the relationship between the S dimension and the beam arrangement, which is the distance between the center beam and the peripheral beam in the deflection center. The inner curvature of the panel is set so as to arrange on the condition that the arrangement GR of the electron beam is 1, and the equation is as follows.

GR ∝ (S × Q) / (Ph × L)

GR: Array of electron beams between R, G, and B

S: Distance between center beam and surrounding beam at deflection center

Q: Distance between panel and shadow mask on the path of electron beam

Ph: Distance of the transmissive space of the shadow mask (horizontal direction)

L: Distance from the deflection center through the electron beam to the inside of the panel

Since Lc in the periphery of the panel becomes larger than Lo in the center of the panel, the Q in the periphery of the panel must be large in order for the electron beam array to be 1. In the form type, it is possible to change the curvature of the shadow mask with respect to the increase of Q, and the inner curvature formula should be Rv≤Rd≤Rh to favor the vacuum stress. In the tension type, the shadow mask is tensioned in the vertical direction, and thus the curvature cannot be given. Therefore, the tension mask is flat without the curvature of the shadow mask in the vertical direction. Therefore, the increase in the Q in the up-down direction is relatively small with respect to the increase in the L in the up-down direction relative to the center Lo in the up-down direction, so that the GR becomes smaller than one. In a state in which it is impossible to cope with the curvature of the shadow mask in the vertical direction, there is a method of changing the inner curvature of the panel to improve this phenomenon. However, in the conventional form-type curvature configuration Rh ≤ Rd ≤ Rv, an arrangement of electron beams that is optimized may be obtained, but it is composed of the most unfavorable conditions for stress.

Figure 6 shows the stress distribution according to the vacuum exhaust of the planar cathode ray tube. As shown in FIG. 6, during vacuum evacuation of the cathode ray tube, the panel effective surface portion is deformed inward of the cathode ray tube and the skirt portion of the panel is deformed outward. In addition, stress is concentrated on the upper and lower skirts during vacuum exhaust, which causes problems of panel breakage. In order to solve this problem, the thickness of the panel must be increased. In this case, the light transmittance is lowered and the luminance is lowered. In addition, breakage is increased in the heat treatment process, resulting in a decrease in productivity.

Accordingly, the present invention is to solve the above problems, the relationship between the horizontal axis, vertical axis, diagonal representative curvature Rh, Rv, Rd of the inner surface of the panel effective surface is Rh≤Rv≤Rd, diagonal thickness Td and the center thickness Tc Is a Td / Tc ≤ 1.35, preferably the plane of the short side thickness Th and the median thickness Tc is 1.0 <Th / Tc <1.4 and the long side thickness Tv and the center thickness Tc is 1.0 <Tv / Tc <1.4 It is to provide a cathode ray tube panel, to improve the explosion-proof characteristics of the cathode ray tube, and to solve the problem of luminance decrease and damage rate increase according to the curvature configuration of the panel.

1 is a cross-sectional view of a general flat cathode ray tube.

Figure 2 is a detailed view of the tension mask and frame assembly.

3A is a plan view of a cathode ray tube panel.

3B is a side view of the cathode ray tube panel.

4 shows the effective surface shape of a flat cathode ray tube panel.

5 is a diagram showing a relationship between an S dimension and a beam arrangement;

6 is a view showing a stress distribution of the planar cathode ray tube according to the vacuum exhaust.

7 is a view showing the relationship between the present invention and the conventional deflection mechanism and flat cathode ray tube panel structure.

8 is a view showing the curvature structure of the present invention and the conventional flat cathode ray tube panel.

*** Explanation of symbols for the main parts of the drawing ***

1: Panel 2: Funnel

3: shadow mask 4: fluorescent surface

5: deflection yoke 6: electron gun

7: Frame assembly 8: Spring

9: inner shield 10: calibration magnet

11: reinforcement band 12: damper

13: Subframe 14: Spring Holder

15: Effective plane 16: Short side

17: long side portion 18: corner portion

19: skirt

Technical solution of the present invention for achieving the above object is a flat cathode ray tube including a panel having a curvature on the inner surface and a tension mask, the distance between the effective surface diagonal axis of the panel is Sd, the horizontal axis of the outer surface The radius of curvature of the vertical and diagonal axes is Rho, Rvo, and Rdo, respectively.The radius of curvature of the inner, horizontal, and diagonal axes is Rh, Rv, and Rd, respectively, and the center thickness is Tc and the diagonal thickness is Td. when doing,

The relationship between the horizontal axis, the vertical axis, and the representative curvatures Rh, Rv, and Rd of the inner surface of the effective surface is Rh≤Rv≤Rd, and the relationship between the diagonal thickness Td and the center thickness Tc is Td / Tc≤1.35, preferably the center thickness, 1.0 <Th / Tc <1.4 and 1.0 <Tv / Tc <1.4 at the same time between short side thickness, long side thickness Tc, Th, and Tv, and long side thickness Tv and diagonal thickness Td are 0.75 <Tv / Td <0.95, The relationship between the short side thickness Th and the diagonal thickness Td is to form a planar cathode ray tube satisfying 0.85 <Th / Td <1.0.

Unlike panels used in form-type shadow masks, panels used in tension-type shadow masks have a problem that the overall thickness increases as the inner curvature is flattened in the vertical direction, and the present invention allows beam arrangements. The present invention provides a planar cathode ray tube panel which can secure a stress without increasing the thickness of the panel within the range.

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

7 is a view showing the relationship between the present invention and the conventional deflection mechanism and flat cathode ray tube panel structure. First, let's look at GRy, an array of electron beams between vertical R, G, and B.

GR ∝ (So × o) / (Ph × o), GRy ∝ (Sy × y) / (Ph × y)

GR (GRy): Array of electron beams between center (vertical side) R, G, B

So (Sy): Center (vertical) center beam and peripheral beam distance from deflection center

Qo (Qy): Distance between the center (vertical) shadow mask and the inside of the center (vertical) panel

Lo (Ly): Distance from the center of deflection through the electron beam to the inner surface of the center (vertical) panel

Since Lo <Ly is geometrically, in order for GR to satisfy 1, the ratio of Qo and Qy must be balanced by the above equation. However, since there is no vertical curvature of the shadow mask, the ratio of Qy / Qo is naturally small. So, in the related art, to solve this by internal curvature, the present invention introduces a method of increasing Sy in the above formula. It is the deflecting device that influences Sy, and increases the Sy by 10% or more compared to the conventional one by further barrelizing the magnetic field inside the conventional deflecting device. Finally, Sy was increased to compensate for Qy / Qo corresponding to Ly / Lo increase, and the new panel's inner and outer curvature and thickness relations were derived.

8 is a view showing the curvature structure of the present invention and the conventional flat cathode ray tube panel. Panels used in tension type shadow masks have a significantly lower wedge rate (Td / Tc) than panels used in foamed type shadow masks. Typically the wedge rate in panels used in tension type shadow masks is Td / Tc &lt; 1.35. The inner curvature structure was changed to Rh ≦ Rv ≦ Rd due to the Sy expansion of the deflector described in FIG. That is, in the present invention, the vertical axis curvature radius Rv of the inner surface of the panel effective surface is made larger than the horizontal axis curvature radius Rh and smaller than the diagonal axis curvature radius Rd.

As the radius of curvature on the vertical side becomes larger, the longer side thickness Tv becomes thinner. Therefore, the stress is concentrated on the vertical side circumference during exhaust and the possibility of breakage increases. In the prior art, Rv / Rh is about 1.4 to 1.6, but in the case of the present invention, as a result of analyzing the vacuum stress, it is preferable to keep Rv / Rh below 1.35.

The following Table 1 shows an example of the mechanical dimensions of the radius of curvature of the panel and its shape when the present invention and the prior art are applied.

division Rh Rv Rd Radius of curvature Invention 8400 8700 10500 Rh≤Rv≤Rd Conventional 8000 12500 10640 Rh≤Rd≤Rv

TABLE 1

Table 2 shows an example and effect of the mechanical dimensions of panel thickness and transmittance when the present invention and the prior art are applied.

TABLE 2

Item Conventional Invention effect Center thickness (Tc) 21.5mm 19.0mm 11.6% ↓ Weight reduction of panels Diagonal Thickness (Td) 28.0mm 24.5mm 12.5% ↓ Central Permeability (%) 33.7 mm 37.1 mm 12.3% ↓ Luminance improvement

In the embodiment of the present invention, the thickness of the cross section, which is vulnerable to vacuum stress, is relatively thicker than the conventional one, which is advantageous for breakage caused by external force. Could. In addition, it was possible to reduce the breakage caused by the thermal stress difference during the thermal process by making the thickness uniform throughout the effective surface area.

Typically, the ratio of the thickness is close to 1.0 in the case of Th / Tc and Tv / Tc, but in the present invention, since it is difficult to cope with the vacuum stress, it is preferable to form in the range of 1.0 to 1.4. In the case of Tv / Td, it is advantageous to be close to 1, but in this case, since there is no curvature in the left and right direction on the vertical side, it is preferable to set the value of 0.75 to 0.95. It is preferable to set it as a value.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the scope of the accompanying drawings. It goes without saying that it belongs to the scope of the present invention.

As described above, in the flat cathode ray tube panel, the thickness difference is reduced over the entire area of the panel effective surface to improve luminance and reduce breakage due to thermal stress during the thermal process, and the horizontal axis, vertical axis, By improving the structure and relationship with respect to the diagonal representative curvature, the short axis, the long axis, and the center thickness, the brightness, the panel weight, and the cost are reduced.

Claims (3)

In a planar cathode ray tube comprising a panel having a curvature on the inner surface and a mask to which tension is applied, The horizontal, vertical and diagonal representative curvatures Rh, Rv, and Rd of the inner surface of the effective surface of the panel are Rh≤Rv≤Rd, and the relationship between the diagonal thickness Td and the center thickness Tc is Td / Tc≤1.35, and the short side thickness Th And the center thickness Tc is 1.0 <Th / Tc <1.4 and the long side thickness Tv and the center thickness Tc are 1.0 <Tv / Tc <1.4 The method of claim 1, The planar cathode ray tube characterized in that the relationship between the long side thickness Tv and the diagonal side thickness Td in the panel is 0.75 < Tv / Td < 0.95. The method of claim 1, A flat cathode ray tube, wherein the relationship between the short side thickness Th and the diagonal side thickness Td in the panel is 0.85 < Th / Td < 1.0