EP0335680A2
Expired / Lapsed
EP
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A cathode ray tube
Assignee: Toshiba Corp
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Filing: 1989-03-29
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Granted: —
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Expires: 2009-03-29
Abstract
Abstract A cathode ray tube (1) comprises an envelope (2) including a faceplate (5) with inner and outer surface and an antistatic layer (10) covering the outer surface of the faceplate for discharging static charges accumulating in the faceplate. The antistatic layer (10) is formed by using a solution containing an alcoholate of silicon as main constituent. The antistatic layer (10) contains a stabilising substance for maintaining antistatic characteristics. The antistatic layer (10) also has light filtering characteristics when the layer contains xanthene dye as filtering substance.
Inventors
- 👤 Takeo C/O Patent Division Itou
- 👤 Hidemi C/O Patent Division Matsuda
- 👤 Hajime C/O Patent Division Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 00:45
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/88; H01J29/89; H01J29/898; H01J29/867; H01J29/868
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
123 words
A cathode ray tube (1) comprising an envelope (2) including a faceplate (5) with inner and outer surfaces and a sidewall portion (7), a neck (3), and, a cone (4) connecting the faceplate to the neck, an electron gun (8) provided inside the neck for emitting at least one electron beam, a phosphor screen (9) provided on the inner surface of the faceplate for emitting a visible light by bombardment of the electron beam, and, an antistatic layer (10) covering the outer surface of the faceplate, characterized in that the antistatic layer (10) is formed from a solution containing an alcoholate of silicon as main constituent and a stabilising substance present in an operative concentration for maintaining antistatic characteristics of the antistatic layer.
Claim 2
Dependent Claim
123 words
A cathode ray tube (1) comprising an envelope (2) including a faceplate (5) with inner and outer surfaces and a sidewall portion (7), a neck (3), and, a cone (4) connecting the faceplate to the neck, an electron gun (8) provided inside the neck for emitting at least one electron beam, a phosphor screen (9) provided on the inner surface of the faceplate for emitting a visible light by bombardment of the electron beam, and, an antistatic layer (10) covering the outer surface of the faceplate, characterized in that the antistatic layer (10) is formed from a solution containing an alcoholate of silicon as main constituent and a stabilising substance present in an operative concentration for maintaining antistatic characteristics of the antistatic layer.
Claim 3
Dependent Claim
31 words
A cathode ray tube according to claim 1 wherein the stabilising substance is organic material which is soluble in water and has molecular weight in the range from 100 to 5000.
Claim 4
Dependent Claim
32 words
A cathode ray tube according to claim 1 wherein the stabilising substance is organic material which is soluble in organic solvent and has molecular weight in the ranges from 100 to 5000.
Claim 5
Dependent Claim
20 words
A cathode ray tube according to any preceding claim wherein the antistatic coating contains 0.01wt% to 75wt% of stabilising material.
Claim 6
Dependent Claim
42 words
A cathode ray tube according to any preceding claim wherein the stabilising substance is at least one selected from the group consisting of anthraquinone group dyes composed of anthraquinone and/or its derivatives, azo group dyes, carbonium dyestuffs, xanthene dyes and phthalein dyes.
Claim 7
Dependent Claim
41 words
A cathode ray tube according to any of claims 3 to 5 wherein the stabilising substance is at least one selected from the group consisting of anthraquinone group dyestuffs composed of anthraquinone and its derivatives, azo group dyes and carbonium dyes.
Claim 8
Dependent Claim
29 words
A cathode ray tube according to any preceding claim wherein the antistatic coating contains moisture absorbent present in an operative concentration for promoting antistatic characteristics of the antistatic coating.
Claim 9
Dependent Claim
26 words
A cathode ray tube according to claim 7 wherein the moisture absorbent is at least one compound of the following elements: Li, Ba, Sr and Ca.
Claim 10
Dependent Claim
161 words
A cathode ray tube (1) comprising an envelope (2) including a faceplate (5) with inner and outer surfaces and a sidewall portion (7), a neck (3), and, a cone (4) connecting the faceplate to the neck, an electron gun (8) provided inside the neck for emitting at least one electron beam, a phosphor screen (9) provided on the inner surface of the faceplate for emitting a visible light by bombardment of the electron beam, and, light filtering means (10) provided in front of the faceplate for selectively transmitting light, characterized in that the light filtering means has maximum absorption wavelength in the range 575±20nm within the wavelength range from 400nm to 650nm and satisfies the relationship: Tmin ≦ T₅₅₀ < T₅₃₀, 1 ≦ T₄₅₀/T₅₃₀ ≦ 2, 1 ≦ T₆₃₀/T₅₃₀ ≦ 2, 0.7 ≦ T₄₅₀/T₆₃₀ ≦ 1.43 wherein T₄₅₀, T₅₃₀, T₅₅₀, T₆₃₀ and T min represent the transmissivities for light of wavelength 450nm, 530nm, 550nm, 630nm and the maximum absorption wavelength, respectively.
Claim 11
Dependent Claim
161 words
A cathode ray tube (1) comprising an envelope (2) including a faceplate (5) with inner and outer surfaces and a sidewall portion (7), a neck (3), and, a cone (4) connecting the faceplate to the neck, an electron gun (8) provided inside the neck for emitting at least one electron beam, a phosphor screen (9) provided on the inner surface of the faceplate for emitting a visible light by bombardment of the electron beam, and, light filtering means (10) provided in front of the faceplate for selectively transmitting light, characterized in that the light filtering means has maximum absorption wavelength in the range 575±20nm within the wavelength range from 400nm to 650nm and satisfies the relationship: Tmin ≦ T₅₅₀ < T₅₃₀, 1 ≦ T₄₅₀/T₅₃₀ ≦ 2, 1 ≦ T₆₃₀/T₅₃₀ ≦ 2, 0.7 ≦ T₄₅₀/T₆₃₀ ≦ 1.43 wherein T₄₅₀, T₅₃₀, T₅₅₀, T₆₃₀ and T min represent the transmissivities for light of wavelength 450nm, 530nm, 550nm, 630nm and the maximum absorption wavelength, respectively.
Claim 12
Dependent Claim
43 words
A cathode ray tube according to claim 9 wherein the light filtering means satisfies the relationship: T 650∼700 < T₆₃₀ when the transmissivity for light of the maximum absorption wavelength in the wavelength region from 650nm to 700nm is shown as T 650∼700
Claim 13
Dependent Claim
49 words
A cathode ray tube according to claim 9 or 10 wherein the filtering means comprises a transparent substrate and a filtering layer which covers the substrate and is formed from a solution containing an alcholate of silicon as a main constituent and filtering substance present in an operative concentration.
Claim 14
Dependent Claim
23 words
A cathode ray tube according to any one of claims 9 to 11 wherein the substrate of the filtering means is the faceplate.
Claim 15
Dependent Claim
29 words
A cathode ray tube according to any one of claims 9 to 11 wherein the substrate of the filtering means is a plate provided in front of the faceplate.
Claim 16
Dependent Claim
20 words
A cathode ray tube according to any one of claims 11 to 13 wherein the filtering substance is xanthene dye.
Claim 17
Dependent Claim
20 words
A cathode ray tube according to any one of claims 9 to 14 wherein the filtering means has antistatic characteristics.
Claim 18
Dependent Claim
29 words
A cathode ray tube according to any one of claims 9 to 15 wherein the filtering means comprises a transparent substrate containing filtering substance present in an operative concentration.
Claim 19
Dependent Claim
40 words
A cathode ray tube according to any one of claims 9 to 16 wherein the filtering means comprises an adhesive resin layer containing filtering substance present in an operative concentration and is provided on the outer surface of the faceplate.
References Cited (Backward Citations)
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