JPH0417242A - Color cathode-ray tube with light selecting/absorbing film - Google Patents

Abstract

PURPOSE:To alleviate a coloring phenomenon of reflection light on a fluorescent screen by specifying absorption peaks of main and sub absorbing bands of a light selecting/absorbing film, respectively. CONSTITUTION:An absorption peak of a main absorbing band of a light selecting/absorbing film 2 is set within 570-610nm of light spectrum wavelengths of green and red lights emitted from a color cathode-ray tube 11. An absorption peak of a sub absorbing band of the light selecting/absorbing film is set within 380-420nm on a short wavelength side of the light spectrum wavelength of blue emitted light or within 470-510nm of the light spectrum wavelengths of the blue and green emitted lights. Therefore, the color cathode-ray tube 11 with the light selecting film can be obtained without any colored reflection light by a neutralization effect of the sub absorbing band even if the absorption peak of the main absorbing band is set within 570-610nm where an effect of contrast enhancement is high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a color cathode ray tube with a light selective absorption film in which a light selective absorption film is formed on the face plate portion.

[Prior Art] As color cathode ray tubes have become larger in size and their brightness performance and focus performance have improved in recent years, the voltage applied to the phosphor screen of the cathode ray tube, that is, the voltage for accelerating the electron beam, has become higher. For example, in conventional color cathode ray tubes of the 21-inch class, the high voltage applied to the phosphor screen was about 25 to 27 KV, but with recent color cathode ray tubes of 30 inches or larger, the voltage applied to the phosphor screen is 30 to 34 KV. Very high pressure is applied. Therefore, especially the 0N-O of the power supply of the TV set
During FF, the outer surface of the face plate of the color cathode ray tube is charged up, and fine dust in the air adheres to the outer surface of the face plate, making the dirt more noticeable, and as a result, the brightness of the color cathode ray tube decreases. This causes performance to deteriorate. Furthermore, when a viewer approaches the charged-up outer surface of the face/brate portion, a discharge phenomenon occurs, causing an inconvenience to the viewer.

Figure 8 is a graph showing changes in the surface potential of the face plate of a cathode ray tube. In the graph, (L) is a curve of changes in surface potential when the power is turned on, and (Ll) is a curve when the power is turned on.
It is a change curve of surface potential at F.

In order to eliminate this charge-up phenomenon on the outer surface of the face plate portion of a cathode ray tube, a smooth transparent conductive film is formed on the outer surface of the face plate portion of the cathode ray tube to release the charge to the ground. Antistatically treated cathode ray tubes have come into use in recent years.

FIG. 7 is a diagram illustrating the principle of preventing static electricity in the above-mentioned antistatic cathode ray tube. In the figure, (6) is a neck portion which houses an electron gun (not shown). (7)
is the deflection yoke, (13) is the funnel part, (4) is the face plate part, (5) is the high voltage button, and the deflection yoke (7) is connected to the deflection power supply via the lead wire (7a). The gun is connected to a drive power source via a lead wire (8a), and the high voltage button (5) is connected to a high voltage power source via a lead wire (5a).

In the cathode ray tube configured as described above, the electron beam emitted from the electron gun built in the neck part (6) is electromagnetically deflected from the outside of the cathode ray tube by the deflection yoke (7), while the high voltage button (
5), a high voltage is applied to the fluorescent screen provided on the inner surface of the face plate portion (4). As a result, the electron beam is accelerated, and its energy excites the phosphor screen to emit light, thereby producing light output. This face plate part (4)
Under the influence of the high voltage applied to the phosphor screen on the inner surface of the face plate (4), the potential on the outer surface of the face plate portion (4) changes as described above, causing problems such as the adhesion of dust.

Therefore, as a measure to eliminate such adverse effects, as shown in FIG. 7, a smooth transparent conductive film (1) is formed on the outer surface of the face plate portion (4).
) is connected to the ground, thereby constantly discharging the charge to the ground and preventing charge-up in the antistatic cathode ray tube (3).

By the way, in this antistatic cathode ray tube (3), in order to ground the transparent conductive film (1) formed on the outer surface of the face plate portion (4), as shown in FIG. - A conductive tape (12) is used to establish electrical continuity between the metal explosion-proof band (8) wrapped around the side wall of the plate part (4) and the transparent conductive film (1). This results in
The metal explosion-proof band (8) is attached to the ground (IOA) by the ground wire (10) hooked to the ear (9), so it is easy to drop the transparent conductive film (1) to the ground. becomes.

Curves (M) and (Ml) in Fig. 8 indicate the power supply ON-OFF state of an antistatic cathode ray tube (3) with a smooth transparent conductive film (1) formed on the outer surface of the face plate. This shows the potential change on the outer surface of the face plate, and it can be seen that the charge-up is significantly smaller than in the past.

The smooth transparent conductive film (1) formed on the surface of the face plate portion (4) is required to have a certain degree of hardness and adhesion, so a silica (SiO2) based film is generally formed.

Conventionally, one of the methods for forming this silica-based smooth transparent conductive film (1) is to use 10H group, -OR group as a functional group.
After applying an alcoholic solution of Si (silicon) alkoxide containing groups, etc., uniformly and smoothly to the outer surface of the face plate portion (4) of the cathode ray tube using a spin cord method, etc., it is baked at a relatively low temperature, for example, 100°C or less. was considered to be a method of processing.

A smooth transparent conductive film (11
) is porous and has silanol groups (S 1-0
H), it can adsorb moisture in the air and lower surface resistance. However, when such a conventional smooth transparent conductive film () is baked at high temperature, not only the -OH of the silanol group disappears, but also the water trapped in the porosity disappears, so the surface The resistance value increases and it becomes impossible to obtain the desired conductivity.

Therefore, low-temperature baking is essential, and the strength of the film is not very strong. Furthermore, if used for a long time in a dry environment, the moisture in the porous material will escape, and the surface resistance value will increase over time. Once moisture escapes from this porous structure, it is difficult for it to penetrate next time.

As described above, the conventional smooth transparent conductive film (1) had major drawbacks in terms of film strength and stability of resistance value over time. In addition, in order to improve these drawbacks, it has been attempted to bond metal atoms such as Zr (zirconium) to the alkoxide structure in the coating liquid to give it conductivity, but it is hoped that this will lead to a significant improvement. Can not do it.

Another method that can fundamentally solve these problems is to add SnO2 (tin oxide) or In as a conductive filler to the alcohol solution of St (silicon) alkoxide.
The face plate part (4) of a cathode ray tube is coated using a coating liquid in which fine particles of 2O3 (indium oxide) are mixed and dispersed, and a trace amount of P (phosphorus) or sb (antimony) is added to impart semiconducting properties. As in the past, there is a method of uniformly and smoothly coating the outer surface of the film using a spin code method or the like and then baking at a relatively high temperature (for example, 100° C. to 200° C.). With this method, it is possible to increase the film strength and obtain a smooth transparent conductive film (1) whose resistance value does not change over time under any environment.

Conventionally, this method was used to prevent static electricity on color cathode ray tubes, but with the recent strong demand for higher image quality in color televisions, this transparent conductive film (1) has been colored to improve the contrast of color cathode ray tubes. A method that also improves the color tone of emitted light has begun to be put into practical use. That is, the conventional coating liquid for obtaining the transparent conductive film (1) is used as a base coating powder, and organic or inorganic dyes or pigments are mixed into the coating powder to create a light-selective absorption coating liquid, which is then spun as in the conventional method.・A color cathode ray tube with a light-selective absorption film that has an antistatic function is created by coating and forming a film on the outer surface of the face and plate of a color cathode ray tube using a coating method. Figure 9 shows an antistatic photo-selective absorption film (2
) is a diagram showing the structure of a color cathode ray tube (11) with an antistatic treated light-selective absorption film (11), in which the parts other than the antistatic light-selective absorption film (2) are of the conventional antistatic treated type shown in FIG. It is exactly the same as the cathode ray tube (3).

Figure 10 shows such a conventional antistatic light selective absorption film (2
) is a diagram for explaining the optical characteristics of.

In the figure, (B) shows the spectral distribution of the relative emission intensity of blue light emitted from the phosphor screen of a color cathode ray tube, and has a light spectral wavelength of about 450 nm. Similarly, (G) and (R) respectively show the spectral distribution of the relative emission intensity of green emission and red emission, and have optical spectral wavelengths at about 535 nm and 625 nm, respectively. Also, (II) and (m) show the spectral transmittance distribution of the face plate (4) on which the fluorescent screen of the color cathode ray tube is formed, and (II) shows the spectral transmittance in the visible light region of about 85%. Clear type, (m) is 50%
The spectral transmittance distribution of the face plate portion (4) of the Tinid medium type is shown. The lower the spectral transmittance of the face plate portion (4), the worse the brightness performance of the phosphor screen of a color cathode ray tube. It is clear from the relationship with distribution that external light entering the phosphor screen of a color cathode ray tube can be effectively removed, which has an advantage in terms of contrast performance. The face/plate part (4) of is often used. In the figure (I) is the face plate part (4) as mentioned above to further improve the contrast performance.
A conventional antistatic photo-selective absorption film (2
) shows an example of the spectral transmittance distribution. 53 between optical spectrum wavelengths of spectral distribution of relative emission intensity of (G) and (R)
If the absorption peak (A) of the antistatic light-selective absorption film (2) exists in a portion close to this wavelength of the optical spectrum between 5 nm and 625 nm, it will be disadvantageous in terms of the brightness performance of the phosphor screen of the color cathode ray tube. Considering the half-width of
The absorption peak (A) of the main absorption band is located in the range of 70 nm to 610 nm. Light in this range of wavelengths corresponds to the relatively high visual sensitivity area of the human eye, so it is called external light (white light).
It is preferable in terms of contrast performance that light in this region of the components is absorbed and removed.

In other words, the optical properties of the antistatic light selective absorption film (2) of the conventional color cathode ray tube (11) with antistatic light selective absorption film are relatively high in terms of visibility for the human eye, and the optical characteristics are relatively high for human eyes. The absorption peak (A) of the main absorption band is placed in the range of 570 nm to 610 nm, which has as little influence on the luminescence of the phosphor screen as possible, in order to effectively absorb external light and improve contrast performance while maintaining the luminance performance of the phosphor screen. That's what I did. It is very important to select an organic dye or pigment that has such optical properties, and in the case of curve (1), 572 nm
An example in which the absorption peak (A) of the main absorption band is given is shown below. In such a color cathode ray tube (11) with an antistatically treated light-selective absorption film, the optical light absorption characteristics of the organic or inorganic dyes and pigments mixed in the base coating powder are relatively broad; Of the light emission, for example, in the case of green light emission, the tail part on the long wavelength side of the light spectrum wavelength, and in the case of red light emission, the subpeak part on the short wavelength side of the light spectrum wavelength are absorbed by this light selective absorption film, improving the light emission color tone at the same time. It is possible to do so.

[Problem to be solved by the invention] In a conventional color cathode ray tube with an antistatic treated light selective absorption film, the optical characteristic of the antistatic light selective absorption film is 570 nm.
Since the absorption peak of the main absorption band is in the range of 610 nm, external light (white light) enters the phosphor screen of the color cathode ray tube with an antistatic treatment type light-selective absorption film and then is reflected and comes out. Since a particularly large amount of light with a wavelength in this range is removed by the main absorption band, a problem arises in that the reflected light is colored. This problem will be explained in more detail with reference to FIG. FIG. 11 shows the locus (IV) of half-width radiation on the CIE chromaticity diagram. The upper part of the horseshoe shape in the figure shows the chromaticity point of each monochromatic light. Ambient light (white light) differs slightly depending on the type, but basically it is a collection of monochromatic lights like sunlight, and typically has a color temperature of about 4500 as shown by point (D). There are many. The color of the phosphor body, including the face Q plate of conventional color cathodes that do not have a light selective absorption film, is almost gray in achromatic colors, and since visible light is absorbed almost equally in the entire wavelength range, it is not reflected by the phosphor screen. The reflected light that comes out has almost the same wavelength components as the incident light, making it a very natural reflected light.

On the other hand, in the case of a conventional color cathode ray tube equipped with a light-selective absorption film that has an absorption peak (A) of the main absorption band at 572 nm as shown in (1) in Figure 10, external light (white light) incident on the phosphor screen Since the light around 572 nm (light) is absorbed and removed by this main absorption band, the chromaticity point of the reflected light shifts in the direction from the chromaticity point (D) of the original external light (white light) that is incident. Move. In other words, on the chromaticity diagram, the chromaticity point of external light (white light) is 4500 (
5 on the line segment connecting D) and the chromaticity point of monochromatic light of 572 nm.
A vector a is generated in the direction away from the chromaticity point of the 72 nm monochromatic light, and the chromaticity point of the reflected light moves, causing the reflected light to be colored.

In the case of a color cathode ray tube, the black level of the image is determined by the color of the phosphor screen itself, and if the reflected light from the phosphor screen is colored, the black becomes very unnatural and affects the quality of the color TV image. It will reduce it significantly.

This invention was made to solve the above problems, and even if the absorption peak of the main absorption band is in the range of 570 nm to 610 nm, which has a very high effect of improving contrast, the reflected light does not have color and color. It is an object of the present invention to provide a color cathode ray tube with a photoselective film that does not cause any damage.

[Means for Solving the Problems] In order to achieve the above object, the color cathode ray tube with a light-selective absorption film of the present invention has an absorption peak in the main absorption band of the light-selective absorption film that corresponds to the green emission of the color cathode-ray tube. and 570 nm to 610 nm between the light spectrum wavelengths of red light emission, and the absorption peak of the sub-absorption band of the light selective absorption film is between 380 nm and 4 nm on the short wavelength side of the light spectrum wavelength of blue light emission.
It is characterized by being in at least one of the range of 200 m and the range of 470 nm to 510 nm between the light spectrum wavelengths of blue light emission and green light emission.

[Function] According to the present invention, even if the absorption peak of the main absorption band of the photoselective absorption film is in the range of 570 nm to 610 nm, which has a very high effect of contrast improvement, the absorption peak of the main absorption band of 380 nm to 4
Due to the neutralization effect of the sub-absorption band having an absorption peak in at least one of the range of 20 nm and the range of 470 nm to 510 nm, it is possible to alleviate the phenomenon of coloring of reflected light from the phosphor screen.

[Example] Embodiments of the present invention will be described below based on the drawings.

The eleventh curve (V) shows an example of the spectral transmittance distribution of the light selective absorption film of the color cathode ray tube with a light selective absorption film according to an embodiment of the present invention. In this case, in addition to the conventional main absorption band having an absorption peak at 572 nm, a sub-absorption band has an absorption peak at 410 nm on the short wavelength side of the light spectrum wavelength of blue light emission (approximately 550 nm). The coloring of the reflected light in this case and the effect of alleviating it will be explained with reference to the CIE chromaticity diagram shown in FIG. In other words, if the chromaticity point of external light (white light) with a color temperature of 4500 is shown by (D), the external light (white light) incident on the phosphor screen is
Light around 572 nm is absorbed by this main absorption band.
Since the reflected light is removed, the chromaticity point of the reflected light moves in a direction that deviates from the chromaticity point (D) of the original incident external light (white light). ) chromaticity point (D
) and the chromaticity point of the 572 nm monochromatic light, a vector a is generated in the direction away from the chromaticity point of the 572 nm monochromatic light, and the chromaticity point of the reflected light moves, causing the reflected light to change color. It sticks to me.

The point where the aforementioned line segment (, e) intersects the horseshoe-shaped line of the chromaticity diagram again coincides with the wavelength of 410 nm. Therefore, as shown in Fig. 1, if there is an absorption peak of the sub-absorption band at <410 nm, a vector (b) will be generated that cancels the vector a caused by the absorption peak of the main absorption band of 572 nm, and the shift in the chromaticity point of the reflected light will be corrected. be done. In order to completely correct this shift in color point between the incident light and the reflected light, it is necessary to balance the absorption amounts of the absorption peaks of the main absorption band and the sub absorption band. In this case, the absorption peak of the sub-absorber is located on the short wavelength side of the light spectrum wavelength (450 nm) of blue light emission, but if it is close to the main spectrum wavelength (450 nm), the brightness of the phosphor screen of the color cathode ray tube will decrease. Since this is disadvantageous in terms of performance, the absorption peak of this sub-absorption band is placed in the range of 380 nm to 420 nm, taking into account the half value of this absorption band.

Similarly, FIG. 2 shows an example (VI) of the spectral transmittance distribution of a light selective absorption film of a color cathode ray tube with a light selective absorption film according to another embodiment of the present invention. In this case, in addition to a main absorption band having an absorption peak at 580 nm, a sub-absorption band has a peak at 4800 m between the optical spectrum wavelengths of blue emission and green emission.

The CIE chromaticity diagram shown in FIG. 5 shows the coloring of reflected light in this case and the effect of alleviating it. The vector C generated by the absorption peak of the main absorption band at 580 nm and the vector d generated by the absorption peak of the sub absorption band at 4800 m cancel each other out, correcting the shift in the chromaticity point of the reflected light. In addition, in this case, the position of the absorption peak of the sub-absorption band is disadvantageous in terms of brightness performance of the phosphor screen of the color cathode ray tube in a portion close to the optical spectrum wavelength of 450 nm to 535 nm between the optical spectrum wavelengths of blue emission and green emission. Therefore, the wavelength is set in the range of 470 nm to 510 nm, taking into consideration the half width of this absorption band.

FIG. 3 similarly shows an example (■) of the spectral transmittance of a light selective absorption film of a color cathode ray tube with a light selective absorption film according to another embodiment of the present invention. In this case, in addition to the main absorption band having an absorption peak at 585 nm, there are two sub-absorption band peaks at 495 nm between the light spectrum wavelengths of blue and green light emission and at 410 nm on the shorter wavelength side of the light spectrum wavelength of blue light emission. . The CIE chromaticity diagram shown in FIG. 6 shows the coloration of reflected light in this case and the effect of alleviating it.

In this case, the vector f generated by the absorption peak of the main absorption band at 585 nm and the composite vector i of vector g and vector h generated by the absorption peaks of the sub-absorber at both 410 nm and 495 nm cancel each other out, resulting in the chromaticity of the reflected light. The point deviation is corrected.

The above describes the case where organic or inorganic coating powder or pigment is mixed into the transparent conductive film of a conventional antistatic cathode ray tube to impart light selective absorption characteristics, but the present invention is not limited to this. It can be similarly applied to transparent films that do not have an antistatic function. Transparent base coating powders are not limited to alcoholic solutions of silicon (Si) alkoxides having 10H or -OR groups as functional groups, but also include plastic coatings such as epoxy resins and acrylic resins. Objects can be used in the same way.

[Effects of the Invention] As described above, according to the present invention, even if the absorption peak of the main absorption band of the light-selective absorption film is in the range of 570 nm to 610 nm, which has a very high effect of improving contrast,
0nm to 420nm range and 470nm to 510nm
Due to the neutralization effect of the sub-absorption bands that have absorption peaks in either or both of the nanometer ranges, the coloring phenomenon of reflected light from the phosphor screen is alleviated, resulting in very excellent contrast performance and the ability to display the body color of the phosphor screen, i.e., color television. It is possible to obtain a color cathode ray tube with a light-selective absorption film that can realize high-quality images with natural black levels.

[Brief explanation of the drawing]

1 to 3 are diagrams showing examples of the spectral transmittance distribution of a light selective absorption film of a color cathode ray tube with a light selective absorption film according to an embodiment of the present invention, and FIGS. The CIE chromaticity diagram explains the coloring of light and the effect of mitigating it. Figure 7 is a diagram explaining the principle of antistatic treatment of antistatic treated cathode ray tubes. Figure 8 is the surface potential of the face plate of a cathode ray tube. 9 is a diagram showing the structure of a color cathode ray tube with an antistatic treated light selective absorption film, and FIG. 10 is a diagram illustrating the optical characteristics of a conventional antistatic light selective absorption film. Figure 11 shows CI for explaining the reflected light of external light of a conventional color cathode ray tube with an antistatic treatment type light selective absorption film.
It is an E chromaticity diagram. In the figure, (1) is a transparent conductive film, (2) is an antistatic light selective absorption film, (3) is an antistatic treated cathode ray tube, (4) is a face plate part, (5) is a high voltage button, (6) is the neck, (7) is the deflection yoke, (8) is the metal explosion-proof band, (9) is the mounting ear, (10) is the ground wire, (IOA)
is ground, (11) is a color cathode ray tube with an antistatic treated light selective absorption film, (12) is a conductive tape, (6a), (
7a) is a lead wire. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Yoshi 1) Kenji (2 others) Han+:, Kikushun Condolence Wani W? □Kan-～No.--4J4-Met2 Dai2L, 1), Jno & Kai times 4th figure Ichijo Motoya 1 Freezejo restaurant pestle? Large 2LIjJ phrase color power b eye figure 5 figure floating! jI-1 Eye Figure 7 Structure ↓Mimeigumi Figure 9 Saki Dai-ku @*Q・4A'lA* i 1. Indication of the case Japanese Patent Application No. 2-122364 2, Name of the invention, Color Cathode Ray Tube with Light Selective Absorption Film 3, Person Making Amendment 4, Agent Not Disciplined! =A rfJ Figure 11: 5, Claims and Detailed Description of the Invention column of the specification subject to amendment. 6. Contents of the amendment Claims Application and formation of a light-selective absorption coating liquid, which is a mixture of an organic or inorganic transparent base paint and an organic or inorganic dye or pigment, on the face plate of a color cathode ray tube. In a color cathode ray tube with a light-selective absorption film, the absorption peak of the main absorption band of the light-selective absorption film is within the wavelength range of 5 between the main spectral wavelengths of green light emission and red light emission of the color cathode ray tube.
70 nm to 610 nm, and the absorption peak of the sub absorption band of the photoselective absorption film is 3800 m to 420 nm on the short wavelength side of the main spectrum wavelength of blue light emission.
1. A color cathode ray tube with a light selective absorption film, characterized in that the color cathode ray tube is in at least one of the ranges of 470 nm to 510 nm between the main spectral wavelengths of blue light emission and green light emission.

Claims (1)

[Scope of Claims] A light selective absorption coating liquid made by mixing an organic or inorganic transparent base paint with an organic or inorganic dye or pigment is applied to the face plate of a color cathode ray tube to form a film. In a color cathode ray tube with an absorption film, the absorption peak of the main absorption band of the light-selective absorption film is located between the light spectral wavelengths of green emission and red emission of the color cathode ray tube.
70 nm to 610 nm, and the absorption peak of the sub-absorption band of the photoselective absorption film is 380 nm to 420 nm on the short wavelength side of the optical spectrum wavelength of blue light emission.
1. A color cathode ray tube with a light selective absorption film, characterized in that the color cathode ray tube is in at least one of the ranges of 470 nm to 510 nm between the light spectrum wavelength of blue light emission and green light emission.