KR20040068381A - A Flat type color CRT - Google Patents

Abstract

PURPOSE: A flat color cathode ray tube is provided to compensate for optical transmissivity differences between the center and peripheral portion of a panel by forming a transmissivity control layer on the outer surface of the panel. CONSTITUTION: A flat color cathode ray tube comprises a panel(1) having an inner surface on which a screen is formed; and a funnel(2) mounted on the rear surface of the panel. The panel has an electromagnetic interference prevention film, an anti-reflection film(15), and a non-glare film(16) formed on the outer surface of the panel. A transmissivity control layer(17) is formed between the outer surface of the panel and the electromagnetic interference prevention film.

Description

Flat color tube {A Flat type color CRT}

The present invention relates to a planar cathode ray tube, and more particularly, to a cathode ray tube panel that forms a transmittance control layer on an outer surface of a panel to compensate for a difference in brightness of a planar cathode ray tube.

As shown in FIG. 1, a general flat CRT is coated with a red, green, and blue fluorescent surface 4 on the inner side, and a panel on which the explosion-proof means is fixed. 1), a funnel 2 fused to the rear end of the panel, an electron gun 11 inserted into the neck portion of the funnel to emit an electron beam 6, and a deflection yoke 5 for deflecting the electron beam 6; And a shadow mask 3 mounted at a predetermined interval inside the panel to form a plurality of holes through which the electron beam 6 passes, and the shadow mask is fixedly supported so that the shadow mask maintains a constant distance from the inner surface of the panel. A frame (7), a spring (8) for connecting and supporting the frame and the panel, an inner shield (9) for shielding the cathode ray tube to be less affected by external geomagnetism, and an external impact provided around the side surface of the panel. It is composed of a reinforcing band 12 to prevent.

In addition, there is a magnet 13 for correcting the trajectory of the electron beam 6 so as to strike the predetermined phosphor accurately, thereby preventing poor color purity. In addition, on the outer surface of the panel 1, an outer surface of the panel 1 includes an antistatic film formed of a material having good conductivity and an antireflection film formed of a material having a different refractive index on the outer surface of the panel 1. Apply.

Looking at the operation of the cathode ray tube having the configuration as described above, when a voltage is first supplied to the stem pin, heat is applied to the cathode, electrons are emitted from the cathode to which the heat is applied. The emitted electrons are focused or accelerated by the sixth electrode at the first electrode.

The electron beam 6 formed by the focused or accelerated emitted electrons is deflected by the deflection yoke 5 and evenly scanned throughout the entire panel 1, and the electron beam 6 is provided with a shadow mask provided in front of the panel 1. It passes through 3) and collides with the phosphor 4 coated on the panel 1 to emit light.

In general, the planar cathode ray tube used for the monitor should prevent the electromagnetic waves and minimize the reflection of the external light from the outside of the front part because the user sees the screen at a close distance.

Therefore, conventionally, as shown in FIG. 2, three coating films 10 formed of an antistatic film 14, an antireflection film 15, and a diffuse reflection film 16 are formed on an outer surface of the panel 1.

That is, one layer is an antistatic film 14, and constitutes an anti-static layer containing an electric conductor for electromagnetic wave prevention and antistatic, and the second layer is an antireflection film ( 15) Anti-glare layer, which constitutes an anti-reflection (hereinafter referred to as AR) layer, and the third layer diffusely reflects external light as a diffuse reflection film 16, thereby reducing external light reflection. It is composed of layers (Anti-Glare, hereinafter called AG).

In general, although the AS layer 14 and the AR layer 15 alone have antireflection and electromagnetic wave prevention effects, the antireflection effect can be increased by adding the AG layer 16.

The panel 1 of the planar cathode ray tube as described above forms the outer surface of the front part of the panel 1 with a large radius of curvature close to the plane, and the inner surface of the fluorescent surface 4 is flat when the screen is viewed from the outside. The radius of curvature is formed with a radius of curvature relatively small compared to the outer surface of the panel 1 so as not to be damaged.

That is, as shown in FIG. 3, the panel 1 of the planar cathode ray tube has a different thickness between the center portion D ₂ and the peripheral portion D ₁ of the front portion of the panel ₁ , and toward both peripheral portions D ₁ . It is thicker than the center part D ₂ . Therefore, the amount of light coming through the front of the central portion (D ₂₎ and the amount of the peripheral portion (D ₁₎ of the panel (1) is bound to vary.

Accordingly, the intensity of the light emitted from the phosphor layer 4 is due to the difference in the thickness of the panel 1, so that the brightness of both peripheral portions D ₁ of the panel ₁ is greater than the brightness of the central portion D ₂ of the panel. Degrades.

In addition, Japanese Patent Laid-Open No. 2001-332196, Korean Patent Laid-Open No. 1999-0050749, and Korean Patent Laid-Open No. 2000-8507 are methods for compensating for the difference in transmittance between the central part and both peripheral parts of the panel, and the thickness of the colored film is different from the central part and both peripheral parts of the panel. It is introduced by forming. In Japanese Patent Laid-Open No. 5-182604, a method of compensating for the difference in transmittance by introducing different colorant densities on the front surface of a panel is introduced.

However, the prior art as described above does not simultaneously perform the role of light transmittance compensation and anti-reflective, or has a disadvantage in that it takes a lot of time and cost in the manufacturing process.

Therefore, although the picture of television or monitor cathode ray tube is ideally the same brightness screen with no difference in luminance between center and surroundings, the difference in light transmittance due to the difference in glass thickness of panel of flat cathode ray tube appears and luminance difference occurs. It was.

Accordingly, an object of the present invention is to solve the above-described problems, and by forming a transmittance control layer formed of carbon black or titanium black, which are colored pigments, on the outer surface of the panel, the center of the panel in the planar cathode ray tube It is an object of the present invention to provide a planar cathode ray tube that compensates for a difference in light transmittance due to a difference in glass thickness between and.

1 is a schematic diagram of a flat color cathode ray tube

Figure 2 is a view showing a coating film of the panel and the panel outer surface according to the prior art.

Figure 3 is a view showing the thickness of the panel center portion and the panel peripheral portion of a typical flat color cathode ray tube.

4 is a view showing a transmittance control layer on the outer surface of the panel according to the present invention.

5 is a graph showing changes in luminance and contrast according to changes in transmittance.

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

1: panel 2: funnel

3: shadow mask 4: phosphor surface

7: frame 9: inner shield

14: antistatic film 15: antireflection film

16: diffuse reflection film 17: transmittance control layer

D ₁ : Panel Peripheral D ₂ : Panel Center

A first technical solution of the present invention for achieving the above object is a flat color cathode ray tube comprising a panel having a screen on the inner surface and a funnel mounted to the rear of the panel; The outer surface of the panel may include an electromagnetic wave prevention film, an antireflection film, and a diffuse reflection film, and may include a transmittance control layer between the panel outer surface and the electromagnetic wave prevention film.

According to a second technical solution of the present invention, the transmittance adjusting layer is formed of at least one of carbon black or titanium black, which is a coloring pigment.

In a third technical solution of the present invention, the thickness of the transmittance adjusting layer is 50 nm or less at the center of the panel, and 20 nm or less at the periphery of the panel.

And preferably, the transmittance of the transmittance adjusting layer is characterized in that 65% ~ 80%.

More preferably, the transmittance of the electromagnetic wave prevention film is characterized in that 70% to 85%.

And the transmittance of the anti-reflective film is preferably characterized in that 55% ~ 70%.

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

The present invention is to configure the transmittance adjusting layer 17 that can correct the transmittance on the outer surface of the panel 1 of the cathode ray tube as shown in Figure 4, the transmittance adjusting layer 17 thickens the coating thickness of the central portion compared to the peripheral portion The coating is adjusted to adjust the transmittance, and the main component is carbon black or titanium black, which are colored pigments. In the center of the panel, the thickness a of the transmittance adjusting layer 17 is 50 nm or less. The thickness b of the transmittance adjusting layer 17 at the periphery thereof is coated to be 20 nm or less.

If the thickness of the transmittance adjusting layer 17 is 50 nm or more at the center portion a or the thickness b of the transmittance adjusting layer 17 is 20 nm or more at the periphery of the panel, the coating layer is thickened on the outer surface of the panel. The transmittance is lowered in both the central part and the peripheral part.

In addition, the transmittance adjusting layer 17 contains components of titanium black or carbon black, which are colored pigments, so that the transmittance can be controlled more easily. The transmittance is formed to be 65% to 80% so that the transmittance of the panel is different from that of the panel. To improve the transmittance.

Meanwhile, looking at the process of forming a coating film on the outer surface of the panel according to the present invention, the transmittance adjusting layer 17 is coated on the outer surface of the panel so that the thickness of the center portion of the panel and the periphery of the panel is different, and the antistatic layer is formed on the transmittance adjusting layer 17. It functions as a spin coating method to apply a coating solution, the main component of ITO, silver (Ag), Pd (Palladium) particles by spin coating method to form an electromagnetic wave shielding film 15, the oxidation having an antireflection function on the electromagnetic wave shielding film 15 A silicon (SiO ₂ ) solution is applied by spin coating to form an antireflection film 16, and finally, a antireflection film 17 is formed by applying a solution containing silicon oxide (SiO ₂ ) as a main component to prevent glare.

In general, the cathode ray tube has a flat outer surface of the panel (1), the inner surface has a constant curvature, and the panel (1) of the flat cathode ray tube having a thickness ratio of the peripheral portion (D ₁ ) to the central portion (D ₂ ) is 150% or more. Due to the difference, the transmittance of the central part and the peripheral part also changes.

Therefore, the peripheral portion (D ₁₎ the central portion (D ₂₎ panel thickness is thin, since the transmittance of the peripheral portion lower than the central portion (D ₂₎ a central portion and a peripheral portion (D ₁₎ a high coaching film if the thickness is uniform transmittance of the central portion of the comparison in ( D ₂ ) causes a bright screen and a low permeability to darken the screen, thereby degrading the luminance uniformity of the cathode ray tube.

Therefore, as shown in Table 1 and Table 2, when the outer surface of the panel is coated by the conventional technology, it can be seen that the luminance value decreases from the central portion D ₂ to the peripheral portion D _{1 of the} panel.

Table 1 transmittance by screen position according to the prior art

Short axis Left center Ooh Prize 79% 78% 80% center 80% 100% 81% Ha 79% 81% 80%

[Table 2] luminance by screen position according to the prior art

Short axis Left center Ooh Prize 23.7 FI 23.4FI 24FI center 24FI 30FI 24.3FI Ha 23.7 FI 24.3FI 24FI

However, in the present invention, the transmittance adjusting layer 17 capable of compensating the transmittance is formed on the outer surface of the panel 1 in order to compensate for the above problems, so that the transmittance and luminance can be compensated for.

That is, according to the present invention, as shown in Tables 3 and 4, the transmittance and luminance difference between the panel peripheral portion (D ₁ ) and the panel center portion (D ₂ ) are small, resulting in uniform luminance throughout the screen.

Table 3 transmittance by screen position according to the prior art

Short axis Left center Ooh Prize 95% 94% 96% center 94% 100% 95% Ha 94% 95% 96%

[Table 4] luminance according to the screen position according to the prior art

Short axis Left center Ooh Prize 28.5FI 28.2FI 28.8FI center 28.2FI 30FI 28.5FI Ha 28.2FI 28.5FI 28.8FI

Meanwhile, in order to secure luminance uniformity, the width of the black mattress applied to the inner surface of the panel 1 is largely increased by 110% to 120%. However, this method causes a problem of deterioration in the purity of the screen. However, according to the present invention, the luminance characteristic can be uniformly obtained on the entire screen without deteriorating the purity characteristic.

And, the transmittance of the transmittance control layer is characterized in that 65% ~ 80%, as shown in Figure 5, when the transmittance is 65% or less the contrast (contrast) of the panel is improved, but the brightness is lowered problem In the case where the transmittance is 80% or more, the luminance is improved, but the contrast decreases. Therefore, the transmittance adjusting layer of the present invention has a transmittance of 65% to 80% so that the luminance and contrast are high. Ensure optimal conditions.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

As described above, the present invention forms a transmittance adjusting layer including carbon black or titanium black pigment on the panel outer surface of the flat color cathode ray tube, thereby solving the nonuniformity of luminance due to the thickness difference between the periphery and the center of the panel. It is also effective in antistatic and electromagnetic shielding, and it is not necessary to adjust the width of the black mattress to overcome the luminance difference, thereby preventing deterioration of purity characteristics.

Claims (4)

A flat color cathode ray tube comprising a panel having a screen on an inner surface and a funnel mounted to a rear surface of the panel; The outer surface of the panel includes an electromagnetic wave shielding film, an antireflection film, and a diffuse reflection film, And a transmittance control layer between the outer surface of the panel and the electromagnetic wave prevention film. The method of claim 1, The transmittance control layer is a flat color cathode ray tube, characterized in that formed of at least one of carbon black (Tibon Black) or a pigment pigment. The method of claim 2, The thickness of the transmittance control layer is a flat color cathode ray tube, characterized in that 50nm or less in the center portion of the panel, 20nm or less in the peripheral portion of the panel. The method of claim 2, The planar color cathode ray tube, characterized in that the transmittance of the transmittance adjustment layer is 65% ~ 80%.