JPH10106450A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube having high luminance and high contrast by arranging filter layers having transmissivity of a specific wave length in blue and green light emitting areas on the under side of blue and green phosphor layers on a panel inside surface. SOLUTION: Preferably, a filter layer on which transmissivity of the light having a wave length of 450nm is larger than that having a wave length of 550nm, is arranged in a blue and green light emtting area on the under side of a blue and green phosphor layer on a panel inside surface. Next, filter layers having colors corresponding to respective colors in respective color light emitting areas just under green and red phosphor layers are respectively arranged on this filter layer or the panel inside surface. In this way, since the filter layers are arranged on the panel inside surface, a color cathode-ray tube on which contrast and color purity are improved and which has high luminance and high contrast, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to a color cathode ray tube having a phosphor layer with a filter.

[0002]

2. Description of the Related Art Conventionally, it has been known that in a color cathode ray tube, an optical filter layer corresponding to the emission color of the phosphor is provided between the phosphor layer on the inner surface of the panel of the face plate to form a phosphor layer with a filter. Have been.

That is, in a normal color cathode ray tube, a phosphor pattern in which phosphor layers of blue, green, and red are arranged in a dot shape, a stripe shape, or the like is formed on an inner surface of a face plate panel. When the electron beam collides with the phosphor layer, the phosphor emits light of each color and an image is displayed. The phosphor layer with a filter has a filter layer composed of a pigment layer of each color and transmitting light of the same color as that of the phosphor layer between the panel and the phosphor layer. Light of green and blue components is absorbed by the red pigment layer, light of green and red components is absorbed by the blue pigment layer, and light of blue and red components is absorbed by the green pigment layer, respectively, to improve image characteristics such as contrast and color purity. It is intended to be improved.

To form such a filter layer,
For example, a slurry in which fine pigment particles and the like are dispersed in a photosensitive liquid composed of polyvinyl alcohol (PVA) and ammonium bichromate (ADC) is applied to the inner surface of the panel by spin coating or the like, dried, and then exposed to ultraviolet light using a shadow mask as an optical mask. Then, a developing method is adopted.
In particular, in the formation of a red filter layer, for example, as disclosed in Japanese Patent Application Laid-Open No. H5-275008, a resist is applied to the inner surface of the panel, and the resist is exposed by exposing a portion other than a predetermined position (filter layer forming position). A method has also been proposed in which after forming a pattern, a red pigment paste is applied thereon, and then the resist film and the pigment coating thereon are peeled off by reverse development.

[0005]

However, these methods for forming a filter layer have the problem that the number of steps is large and complicated. Therefore, in a color cathode ray tube, it has been required to form a phosphor layer with a filter in a simplified and small number of steps.

The present invention has been made in view of such circumstances, and provides a color cathode ray tube having a high-brightness and high-contrast color filter having a filter layer with good characteristics formed in a simplified and small number of steps. The purpose is to do.

[0007]

The color cathode ray tube of the present invention has an optical filter layer on the inner surface of a panel of a face plate, on which phosphor layers of three colors of blue, green and red are arranged in a predetermined pattern. In the color cathode ray tube having the phosphor pattern formed, the transmittance of light having a wavelength of 450 nm is provided on the entire inner surface of the panel or on the inner surface of the panel below the blue and green phosphor layers in the blue and green light emitting regions. Is wavelength 5
A filter layer larger than 50 nm is provided, and on the filter layer or on the inner surface of the panel, in a light emitting region of each color immediately below the green and red phosphor layers, a filter layer of a color corresponding to each of the colors is provided. It is characterized by having been provided.

In the present invention, as a filter layer having a transmittance of light having a wavelength of 450 nm larger than that having a wavelength of 550 nm,
For example, a blue filter layer can be mentioned.

In the present invention, the formation of each color filter layer including the blue filter layer is performed, for example, in the following procedure.

That is, first, a pigment dispersion containing pigment particles of a predetermined color and a polymer electrolyte dispersant as main components is applied to an inner surface of a panel having a black matrix. As the pigment, any of an inorganic or organic pigment can be used, but it can be uniformly dispersed in the filter layer and is sufficiently transparent to the filter layer without causing light scattering. It is preferable to use a pigment capable of imparting properties. In the production of color cathode ray tubes,
The use of an inorganic pigment is particularly preferred because it involves a high-temperature step. Furthermore, as a coating method of the pigment dispersion, a spin coating method, a roller method, a dipping method, and the like can be used,
It can be appropriately selected in consideration of the shape and size of the face plate. In order to obtain a uniform and predetermined film thickness, it is particularly preferable to use a spin coating method.

After applying the pigment dispersion in this manner, the coating film is dried. Any drying method can be used as long as it can evaporate water and dissociate a part of the salt in the polymer electrolyte salt. Without particular limitation, various methods such as drying with a heater, drying with hot air, and drying for a long time at room temperature can be used.

Next, a predetermined pattern is formed from the obtained pigment layer. To perform patterning only with the pigment layer, ADC / PVA, sodium dichromate (SDC) / PVA, diazonium salt / PVA and the like may be contained. If a pigment layer containing such a photoresist is applied and formed, a portion irradiated with light (ultraviolet light) is cured by exposure using a high-pressure mercury lamp or the like, and then becomes insoluble in water or the like. By developing using an alkaline aqueous solution containing a substance that solubilizes the electrolyte, a filter layer having a predetermined pattern can be formed.

Further, instead of including the photoresist in the pigment dispersion liquid, a pigment layer is applied and formed, and then a photoresist layer is formed thereon, so that exposure and development can be performed. . In such a case, the photosensitive characteristics can be improved, that is, the exposure time can be shortened and the adhesion can be improved, and the thickness range of the formed filter layer can be expanded.

In the present invention, these series of steps are first performed for blue, so that the entire inner surface of the panel or the blue and green light-emitting regions immediately below the phosphor layers having blue and green light-emitting colors on the inner surface of the panel are provided. A blue filter layer is formed, and then green, red or red and green are repeated in this order, thereby forming a filter layer of a color corresponding to a predetermined region. further,
On the filter layer thus formed, blue, green, and red phosphor layers are respectively formed in a predetermined pattern by a usual slurry method.

In the first aspect of the present invention, a blue filter layer is provided on the entire inner surface of the panel, and green and red light-emitting regions (regions immediately below the phosphor layers having green and red light-emitting colors) thereon are provided. In (2), since the green and red filter layers corresponding to each color are provided, patterning is not required for forming the blue filter layer, and the process can be simplified. In addition, a filter layer having good transmission characteristics can be obtained.

That is, in the blue light emitting region immediately below the phosphor layer having the blue light emission color, only the blue filter layer is formed, so that the contrast and the color purity are improved and the luminance is hardly reduced. . In the green light-emitting region, a blue filter layer is provided in the lower layer in the same manner as the blue light-emitting region, and a green filter layer is further formed thereon, so that the green filter layer is provided alone. In this case, the transmittance of light in the green region is higher than that of the green filter, and the green filter has more excellent spectral transmission characteristics. Further, in the red light emitting region, the red filter layer is further formed on the blue filter layer provided on the entire inner surface of the panel, so that the transmitted light becomes closer to neutral, but as a red filter. It has sufficiently good spectral transmission characteristics.

In a color cathode-ray tube having a filter layer having high transmission efficiency of light in the blue and green regions, a color cathode-ray tube provided with blue, green, and red phosphor layers without a filter is used. In comparison, the luminance is high and the contrast characteristics are excellent.

Further, the blue filter layer is provided not in the entire inner surface of the panel but in the blue and green light-emitting regions, and a green filter layer is provided on the green light-emitting region on the filter layer. In the filter pattern in which the red filter layer is provided in the red light emitting region on the inner surface of the panel, while the purity of the transmitted light in the green light emitting region is improved, the color purity in the red light emitting region does not decrease. Therefore, by using such a filter, it is possible to obtain a color cathode ray tube having higher luminance and excellent contrast characteristics.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to the following examples.

Example 1 As a black matrix, a color cathode ray tube panel in which a light absorbing layer of a predetermined pattern made of, for example, graphite is formed by a known method is provided on the inner surface of each panel (blue, green, The red) filter layer was formed by first forming a blue filter layer on the entire panel, then a green filter layer on a green light emitting region and a red filter layer on a red light emitting region. The formation of the filter layers of each color was performed as described below.

That is, as the blue pigment particles, 30 parts of cobalt blue X (particle size: 0.01 μm to 0.02 μm, manufactured by Toyo Pigment Co., Ltd.) are used.
Wt%, PVA with ΑDC added as photoresist
0.5% by weight and an ammonium salt of a polyacrylic acid copolymer (trade name: Dispec GA-40, manufactured by Allied Colloids) as a polymer electrolyte at a ratio of 0.7% by weight in pure water. A dispersion was prepared. Also, 30% by weight of dipiroxide side green # 3320 (particle diameter: 0.01 μm to 0.02 μm, manufactured by Dainichi Seika) as green pigment particles,
A green pigment dispersion is prepared by dispersing 2% by weight of {DC / PV} as a photoresist and 0.7% by weight of sodium salt of acrylic acid (trade name: Dispec N-40) as a polymer electrolyte in pure water. did. Further, Fe ₂ O ₃ fine particles (particle diameter: 0.01 μm to 0.02 μm) are used as red pigment particles.
m) 30% by weight, ADC / PVA as photoresist
2% by weight, and a polyoxyethylene alkyl ether sulfate ammonium salt (HITENOL 08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) at a ratio of 0.7% by weight as a polymer electrolyte in pure water. Prepared.
First, the blue pigment dispersion is applied to the inner surface of the panel of the color cathode ray tube maintained at a temperature of 30 ° C.
After spinning off the excess pigment dispersion by rotating at 0 rpm to form a coating layer having a constant film thickness, at a heater temperature of 120 ° C., 3 to
After drying for 4 minutes, a blue filter layer was formed on the entire surface of the panel.

Next, a green pigment dispersion liquid is applied and dried in the same manner to form a green pigment coating layer on the whole of the blue filter layer, and is then exposed to a predetermined pattern by irradiating ultraviolet rays through a shadow mask. And then a mist of developer, for example L
Developing by spraying an alkaline aqueous solution of pH 9 containing iCl to form a green filter layer in a green light emitting region. Further, over the green filter layer thus formed and the blue filter layer described above,
The red pigment dispersion was applied and dried, and the exposure, development, and drying steps were performed in the same manner to form a red filter layer in a red light emitting region.

Thereafter, a blue phosphor layer is formed on the blue filter layer (exposed portion not covered with the green and red filter layers), a green phosphor layer is formed on the green filter layer, and a red phosphor layer is formed on the green filter layer. A red phosphor layer on the filter layer,
Each was formed in order by the usual slurry method.

In the phosphor layer with a filter formed on the inner surface of the panel, only the blue filter layer is provided in the blue light emitting region below the blue phosphor layer, so that the contrast and the color purity are improved. And there is almost no decrease in luminance. Further, in the green light-emitting region below the green phosphor layer, a green filter layer is further provided on the blue filter layer, and therefore, as apparent from the transmittance graph shown in FIG. The transmittance of light in the wavelength region of 550 to 600 nm, which has high sensitivity, is reduced,
Since the transmittance of light in the green region of 550 nm is high, the color purity of transmitted light is higher than when a green filter layer is provided alone, and the green filter has more excellent transmission characteristics. By the way, if the green filter layer alone,
The transmittance of light in the wavelength region of 00 nm cannot be sufficiently reduced, and transmitted light with high color purity cannot be obtained. Further, in the red light emitting region below the red phosphor layer, the red filter layer is further provided on the blue filter layer,
As is clear from the graph shown in FIG. 3, the transmitted light approaches neutral, but has sufficiently good transmission characteristics as a red filter.

When the BCP (brightness / contrast characteristics) of the color cathode ray tube having such a filter layer was determined, the value was 1.077 times higher than that of the color cathode ray tube without the filter layer. It turned out that it was high and was excellent in contrast characteristics.

Example 2 On the inner surface of the panel of a color cathode ray tube having a light absorption layer of a predetermined pattern formed as a black matrix, filter layers of blue, green and red having transmittance shown in FIG. After forming a blue filter layer in the light emitting area of
A green filter layer was formed in a green light emitting region thereon, and a red filter layer was formed in a remaining portion (red light emitting region) of the inner surface of the panel where the blue filter layer was not formed, in the same manner as in Example 1. .

Next, a blue phosphor layer is placed on the blue filter layer (exposed portion not covered with the green filter layer) of the filter pattern thus formed, a green phosphor layer is placed on the green filter layer, and a red filter Red phosphor layers were sequentially formed on the layers by a usual slurry method.

The BCP of the color cathode-ray tube having such a phosphor layer with a filter was determined to be 1.105 times that of the color cathode-ray tube without a filter layer. It was found that the contrast characteristics were excellent.

[0029]

As is apparent from the above description, the color cathode ray tube of the present invention is provided with a filter having good transmission characteristics especially in the blue and green light emitting regions, and has high luminance and excellent contrast characteristics. . Further, the filter pattern in the color cathode ray tube of the present invention can be formed in a simplified and small number of steps, and the productivity is high and the production cost is not required.

[Brief description of the drawings]

FIG. 1 is a graph showing the transmittance of each color filter layer formed in Example 1 of the present invention.

FIG. 2 is a graph showing transmittance in a green light emitting region in the filter pattern obtained in Example 1 of the present invention.

FIG. 3 is a graph showing transmittance in a red light emitting region in the filter pattern obtained in Example 1 of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuhisa Nakao 1-9-2 Hara-cho, Fukaya-shi, Saitama Pref.

Claims (2)

[Claims] 1. A color cathode ray tube having an optical filter layer on an inner surface of a panel of a face plate, and a phosphor pattern in which phosphor layers of three colors of blue, green and red are arranged in a predetermined pattern thereon. Provided on the entire inner surface of the panel is a filter layer having a transmittance of light at a wavelength of 450 nm larger than that of a wavelength of 550 nm, and on the filter layer, in the light-emitting regions of the respective colors immediately below the green and red phosphor layers, A color cathode ray tube characterized in that a filter layer of a color corresponding to the above is provided. 2. A color cathode ray tube having a phosphor pattern in which an optical filter layer is provided on an inner surface of a panel of a face plate and phosphor layers of three colors of blue, green, and red are arranged in a predetermined pattern thereon. On the inner surface of the panel, a filter layer having a transmittance of light at a wavelength of 450 nm larger than that of a wavelength of 550 nm is provided in a blue and green light-emitting region below the blue and green phosphor layers, and the green color is formed on the filter layer. A color cathode ray tube, wherein a green filter layer is provided in the light emitting region of (1), and a red filter layer is provided in a red light emitting region below the red phosphor layer on the inner surface of the panel.