KR100464282B1 - The Color Cathode-Ray Tube - Google Patents

Abstract

The present invention provides a panel having a phosphor screen on an inner surface, a funnel connected to the panel, a vacuum container including a neck portion of the funnel, an electron gun mounted to the neck portion to emit an electron beam toward the phosphor screen, and an inner surface of the panel. A plurality of shadow masks are disposed at regular intervals with respect to the phosphor screen of the vacuum mask, and a frame attached to the inner surface of the panel to fix and support the shadow mask, and an inner shield that acts as a geomagnetic shield. In the color cathode ray tube including a component, a film is formed of a material having an atomic number lower than that of iron (Fe) on the surface of at least one component among a plurality of components mounted inside the cathode ray tube.

The present invention forms a coating film on the surface of the shadow mask, the frame and the inner shield with aluminum and carbon having a low atomic number to absorb scattered electrons without passing through the shadow mask hole, thereby improving the screen quality by widening the color reproduction range of the screen. It is effective to let.

Description

Color Cathode Tube {The Color Cathode-Ray Tube}

The present invention relates to a color cathode ray tube, and more particularly, to a color cathode ray tube that removes scattered electrons present inside the cathode ray tube to improve the color reproduction range of the screen.

In the general color cathode ray tube, as shown in FIG. 1, R, G, and B fluorescent surfaces 4 are coated on the inner surface, and a panel 1 having explosion-proof means is fixed to the front portion, and a rear end of the panel. A fused funnel (2), an electron gun inserted into the neck portion of the funnel to emit an electron beam (6), a deflection yoke (5) for deflecting the electron beam (6), and a predetermined distance inside the panel A shadow mask (3) mounted and formed with a plurality of holes through which the electron beam (6) passes, a frame (7) fixedly supporting the shadow mask so that the shadow mask is kept at a constant distance from the inner surface of the panel, and the frame and the panel It is composed of a spring (8) for connecting and supporting, an inner shield (9) for shielding the cathode ray tube to be less affected by external geomagnetism, and a reinforcing band (11) installed around the side of the panel to prevent external impact.

In addition, there is a magnet (10) for correcting the trajectory of the electron beam to strike the predetermined phosphor accurately to prevent poor color purity.

The hot electrons of red (R), green (G), and blue (B) emitted from the cathode of the electron gun are accelerated by the accelerating electrode and are deflected in a desired direction by the deflection yoke to reach the shadow mask. Likewise, the light is emitted through the shadow mask to react with phosphors of red (R), green (G), and blue (B). At this time, about 20% of the electron beams reaching the shadow mask reach the fluorescent surface through the shadow mask hole to emit phosphors, but about 80% of the electron beams do not pass through the shadow mask hole and collide with the shadow mask as shown in FIG. 2B. Heat energy is generated or returned in the direction it came from. Electrons that do not pass through the shadow mask hole are referred to as back scattered electrons (BSE). Most of the electrons collided with the shadow mask lose energy while releasing thermal energy, but some of these electrons exist inside the cathode ray tube with only the direction changed while maintaining the initial velocity (energy).

Scattered electrons having the initial energy are present in the cathode ray tube and collide with the inner shield 9, the shadow mask 3, the frame 7, etc., and are partially absorbed and some emit light. At this time, the phosphor emission by the scattered electrons is because the color of the screen is reduced since all of the phosphors of the red (R), green (G), blue (B) of the monochromatic electron beam emits light.

Degradation of the color purity by the scattering electrons is shown through the chromaticity diagram of FIG. 3 defined by the Commission for International Lighting (Commission International De L'eclALrage: CIE) in 1931, where the scattering electrons do not exist. Compared to the other case, the color reproduction area is about 20% narrower. In other words, even if a user sends a red signal to implement red, the screen displays reddish orange or pink near red. Difficult to implement video

4 illustrates a result of applying a phosphor to a periphery and a neck without applying a phosphor to the center of the screen in order to see the influence of scattered electrons. As shown, the phenomenon in which the phosphor emits light occurs in the neck part. In this case, since the electron beam caused by the deflection is structurally impossible to emit the phosphor in the neck part, the emission phenomenon is a factor for emitting the phosphor while the scattered electrons exist in the cathode ray tube. Show what's working

5 is a schematic diagram showing the phosphor emission phenomenon by the electron beam. That is, in the case of a, the accelerated hot electrons emitted from the electron gun are deflected by the deflection yoke and pass through the shadow mask to emit red (R), green (G), and blue (B) phosphors. Scattered electrons are generated as described above. The scattered electron generation process can be largely divided into two types. First, the deflected electron beam does not pass through the shadow mask hole and collides with the shadow mask (b) and secondly collides with the inner shield (C) to partially cancel and partially After scattering electrons, they pass through the shadow mask hole and react with the phosphor on the screen (d) to emit the phosphor, and after the deflected electron beam does not pass through the shadow mask hole and collides with the shadow mask (e) secondly collides with the inner surface of the funnel. (f) some of them are offset and some of them are scattered electrons, which may cause a third collision with the inner shield (g), where the scattered electrons collide with the inner shield and lose energy or are not absorbed and continue in the third and fourth order. Collision will worsen the properties of the cathode ray tube.

Therefore, an object of the present invention is to remove the scattering electrons present in the cathode ray tube by forming a film on the surface of the shadow mask, frame, inner shield and the like scattered electrons to solve the above problems.

1 is a cross-sectional view of a common color cathode ray tube

2A to 2B are diagrams illustrating a scattering electron generation phenomenon.

3 is C.I.E. Figure showing the color coordinate system

4 is a view showing a light emission phenomenon inside a cathode ray tube by scattered electrons;

5 is a view showing a phosphor emission phenomenon by the scattering electrons

6 is a correlation diagram between scattering electrons and metal atoms

7 is a diagram showing a relationship between scattered electrons and a metal atomic number

8 shows the relationship between the atomic distance and the binding energy.

9 is a view illustrating scattered electron absorption through an uneven portion of an inner shield surface;

10 is a diagram showing scattered electron absorption on an inner shield surface where no uneven portion is formed.

11 is a view showing a cross-sectional shape of the multi-coating film of the inner shield for the scattering electrons removed

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

3: shadow mask 6: electron beam

7: frame 9: inner shield

20: coating film 30: inner shield surface irregularities

The technical means of the present invention for achieving the above object is a vacuum vessel consisting of a panel having a phosphor screen on the inner surface, a funnel connected to the panel, the neck portion of the funnel, and an electron beam mounted to the neck portion toward the phosphor screen An electron gun emitting light, a shadow mask arranged at a predetermined interval with respect to the phosphor screen on the inner surface of the panel to serve as color screening, a frame attached to the inner surface of the panel to fix and support the shadow mask, and an inner magnetic shielding role. In a color cathode ray tube including a plurality of parts inside the vacuum vessel, such as a shield, a material having an atomic number lower than that of iron (Fe) on the surface of at least one of the plurality of parts mounted inside the cathode ray tube. A film is formed.

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

The degree of absorption of scattered electrons generated in the cathode ray tube is determined by the material and thickness of the coating film. First of all, as shown in FIG. 6, a part of the incident electron E ₀ collides with the metal atom nucleus, disappears or is absorbed, and a part is deflected to have an angle a, passes through the atom, and then with the metal atom of the next layer. Crash or deflect again. Therefore, the scattered electron absorption amount (η = scattered electron number / incident electron number) increases as the distance between atoms gets closer.

η = -0.0254 + 0.016Z-0.000186Z ² + 8.3 × 10-7Z ³

In which Z is an atomic number. 7 is shown as a graph. That is, as the atomic number increases, the absorption of scattered electrons increases in the form of LOG function.

8 shows the binding energy according to the distance between atoms. As atoms move closer to each other, force acts between them, with repulsive forces between the nucleus and the nucleus, and between electrons and electrons. In addition, since atoms share free electrons with each other, the attraction between the electrons and the nucleus acts to decrease the distance between the atoms, thereby increasing the binding energy. However, when the distance between atoms is closer than a certain level, the repulsive force between the nucleus increases sharply and the binding energy decreases. Therefore, the interatomic distance, or atomic number, is determined at point A, where the energy level is lowest.

In addition, the surface reflectance of the metal material is 30% for the main material (Fe) of the mask, inner shield and frame, 42% for the barium (Ba), 6.4% for carbon (C) of the getter (Getter). However, since the inside of the cathode ray tube is mostly composed of a mask, an inner shield, a frame, and the like, iron (Fe), which is a main component thereof, becomes a main cause of scattered electron generation. Therefore, in order to remove the scattering electrons, a coating film must be formed of a material having a lower atomic number and lower reflectance than the iron component (atomic number; 26).

In order to remove the scattered electrons, a coating film is formed of a material having an atomic number smaller than that of iron on both surfaces or one surface of a shadow mask having the most collision with hot electrons in a cathode ray tube, and a frame and an inner shield of a support of the shadow mask.

In order to prove the effect of the present invention, a method of depositing aluminum having a small atomic number (Al; atomic number 13) on a shadow mask, a graphite film coating method of applying a black matrix (BM) on the shadow mask, and mainly used for dope improvement The coating film was formed on the shadow mask by the metal oxide film formation method to measure the scattering electron removal effect. In this case, the measurement methods and conditions are used for driving a typical cathode ray tube. LK is 600, raster luminance is 0.06FL, and color coordinates are coordinate values of CIE color coordinate system as x = 0.283 and y = 0.298. The scattering electron removal effect is expressed by the luminance and color coordinate values of the raster. The experimental results are shown in Table 1 below.

Table 1

Shadow Mask Surface Condition Luminance Color coordinates (x / y) R G B BM application 20 fL 0.626 / 0.328 0.292 / 0.585 0.144 / 0.071 Oxide film formation 25 fL 0.621 / 0.326 0.293 / 0.583 0.146 / 0.072 Aluminum deposition 30 fL 0.630 / 0.328 0.294 / 0.590 0.144 / 0.070 Prior art 30 fL 0.621 / 0.326 0.293 / 0.584 0.146 / 0.072

As shown in Table 1, carbon (C), which is the main raw material of BM coating, has an atomic number of 6 and a distance between atoms is smaller than iron (Fe), so that the color coordinate (x / y) of red (R) is 0.005 compared to the prior art. /0.002 was improved. In fact, improving color coordinates with phosphor alone requires a tremendous amount of time and money. However, since BM was applied on the surface of the shadow mask as it is, the phenomenon of covering the hole of the shadow mask occurred, which caused a problem of decreasing the brightness by about 1/3. In addition, the method of improving the scattering electrons through the metal oxide film was not effective.

When the thickness of the film is more than 2500Å, the electron beam does not pass directly. Therefore, if the thickness of the coating is not more than 2500Å, the film does not have a great influence, and the permeation characteristics change only depending on whether the coating is evenly applied.

As another embodiment of the present invention after forming a coating film on the inner shield was measured scattering electron removal effect. At this time, the coating film was formed by an aluminum (Al) deposition method, a black matrix (BM) coating method, and an embedded graphite coating method in which nickel (Ni) having a larger atomic number than iron (Fe) was the main raw material. The experimental results are shown in Table 2.

TABLE 2

Inner shield surface condition Color coordinates (x / y) R G B BM application 0.624 / 0.329 0.293 / 0.586 0.145 / 0.072 Built-in graphite 0.618 / 0.331 0.294 / 0.582 0.145 / 0.073 Aluminum deposition 0.623 / 0.328 0.294 / 0.586 0.145 / 0.072 Prior art 0.621 / 0.326 0.293 / 0.584 0.146 / .0072

As a result of the experiment of Table 2, the BM coating method uses the color coordinate of red (R) because the atomic number (6) of carbon (C), which is the main raw material, is smaller than that of iron (Fe), as in the case of the shadow mask. Is improved by 0.003 / 0.003 over the prior art. In addition, when the coating film was formed on the inner shield by the AL (atomic number; 13) deposition method, the result was similar to the BM coating method. As a result, the lower the atomic number, the better the scattering electron absorption characteristics, and the thickness of the coating film is not very large because it is very thin in the case of AL deposition film as 2500 ,, it only changes depending on whether the film is evenly applied.

However, when internal graphite is applied to the inner shield, the main raw material of the internal graphite is nickel (Ni; atomic number 28), which has a higher atomic number than iron (Fe) and has a higher resistivity, so that the amount of scattered electrons is higher than that of the conventional shield. This increase was confirmed to deteriorate the quality characteristics.

Therefore, in order to reduce the amount of scattered electrons, it is important to use a material having a lower atomic number than Fe, and the aluminum deposition method and the BM graphite film coating method that can use the existing equipment without significant change and replacement of the mass production process are appropriate. .

The aluminum deposition method is easy to deposit inner shield and excellent bonding strength, there is no risk of foreign substances in the CRT. In addition, the BM graphite film coating method, in which carbon (C) is the main raw material, may cause the carbon film to fall off due to high temperature and external impact, but such a problem may be solved by the gravure method. The gravure method has an advantage in that the coating film is coated with the inner shield while being coated together, and the bonding strength is excellent, and above all, the film does not fall even under high temperature and impact, and the concentration can be partially adjusted to obtain more excellent characteristics.

9 illustrates another embodiment of the present invention, which is intended to improve scattering electron absorption characteristics by forming an uneven portion 30 on the inner shield surface. When only the coating film 20 for removing the scattered electrons is simply formed in the inner shield as shown in FIG. 10, it is impossible to completely remove the scattered electrons, but the scattered electrons arriving on the inner shield surface by forming the uneven portions on the inner shield surface are formed by the unevenness. It is scattered again and absorbed into the coating film.

11 is to maximize the scattering electron absorption characteristics by applying a coating film of the inner shield in another embodiment as an embodiment of the present invention. That is, the primary coating layer 20 is formed of a material having a low atomic number to absorb scattered electrons, and the secondary coating layer 21 is formed of a material having low electrical resistance on the primary coating layer to increase scattering electron absorption characteristics. It was made. The secondary coating film has an advantage of maximizing the scattering electron removal effect by using a material having a high atomic number but excellent electrical properties.

As described above, the present invention forms a coating film of aluminum, carbon, etc. having a low atomic number on the surface of the shadow mask, the frame, and the inner shield to absorb the scattered electrons without passing through the shadow mask hole, thereby reducing the color reproduction range of the screen. It has the effect of widening the screen quality.

Claims (12)

A panel having a phosphor screen on an inner surface, a funnel connected to the panel, a vacuum vessel consisting of a neck portion of the funnel, an electron gun mounted on the neck portion to emit an electron beam toward the phosphor screen, and a phosphor screen on the inner surface of the panel It includes a plurality of parts inside the vacuum vessel, such as a shadow mask disposed at regular intervals to serve as color screening, a frame attached to the inner surface of the panel to securely support the shadow mask, and an inner shield serving as a geomagnetic shield. In the color cathode ray tube which And a film formed of a material having an atomic number lower than that of iron (Fe) on a surface of at least one of the shadow mask, the frame, and the inner shield mounted inside the cathode ray tube. The method of claim 1, The material of the film is one or a mixture of two or more of the metal elements scandium (Sc), titanium (Ti) and manganese (Mn) and one of the compounds thereof, The scandium (Sc) is 0.01wt% or less, the titanium (Ti) is 0.02 wt% or less, the manganese (Mn) is a color cathode ray tube, characterized in that. The method of claim 1, The material of the membrane is one or a mixture of two or more of the base metals of carbon (C), sodium (Na) and magnesium (Mg) and compounds thereof, The carbon (C) is 0.01 wt% or less, the sodium (Na) is 0.01 wt% or less, the magnesium (Mg) is 1 wt% or more 5 wt% or less characterized in that the color cathode ray tube. The method of claim 1, The color cathode ray tube, characterized in that the thickness of the film is locally made different. The method of claim 1, A color cathode ray tube, characterized in that the film is formed in multiple layers, but the material is different for each layer. The method of claim 1, Color cathode ray tube, characterized in that the uneven portion formed on the inner shield surface. The method of claim 1, Color cathode ray tube, characterized in that the oxide film is formed on the inner shield surface to improve the heat absorption characteristics and scattered electron absorption rate. delete delete The method of claim 1, Color cathode ray tube, characterized in that to improve the surface heat radiation by forming an oxide film on the surface of the component mounted inside the cathode ray tube. The method of claim 1, Color cathode ray tube, characterized in that the components mounted inside the cathode ray tube comprises a metal material such as shadow mask, inner shield, frame. The method of claim 1, The cathode mounted inside the cathode ray tube is a color cathode ray tube, characterized in that it comprises a non-metallic material, such as embedded graphite, barium (Ba) of getters (Getter).