Color cathode ray tube and method of manufacturing thereof
AssigneeHitachi, Ltd.
InventorsMasahiro Nishizawa, Norikazu Uchiyama, Maki Taniguchi, Toshio Tojo, Tomoji Oishi
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Abstract
A cathode ray tube includes a film which is formed on an outer surface of a panel portion. The film is comprised of a first particles which become transparent due to the oxidation and a second particles which are chemically and physically stable and have the light absorbing ability and the conductivity. A number of the transparent first particles is gradually increased toward a peripheral portion from the center portion of the panel portion.
Claims12
A color cathode ray tube comprising a panel portion which constitutes an image display surface, a neck portion housing an electron gun and a funnel portion which connects the panel portion and the neck portion,
- the panel portion having a light transmission control layer and a low refractive index layer,and
- the light transmission control layer including a first particles which become transparent due to the irradiation of light or due to the irradiation of light and the oxidation on an outer surface of the panel portion and a second particles having the light absorbing ability and the conductivity, and a number of the transparent particles of the first particles is gradually increase toward a peripheral portion from a center portion of the panel portion, and
- a low refractive index layer which has a refractive index lower than a refractive index of the light transmission control layer is formed as a layer above the light transmission control layer.
A manufacturing method of a cathode ray tube having a panel portion which constitutes an image display surface comprising steps of:
- a first coating step in which a first dispersing liquid which is produced by mixing a first metal particles and a second particles which exhibits the light absorption ability and holds the conductivity into a solvent is coated on an outer surface of the panel portion to form a first coating layer,
- a gradation exposure step in which the first coating layer is exposed in the oxidative atmosphere through an optical filter which increases the transmittivity toward a periphery from a center of the panel portion, and the first metal particles which become transparent due to the irradiation of light or due to the irradiation of light and the oxidation are made transparent corresponding to a quantity of exposure light which passes through the optical fiber,
- a second coating step in which a second dispersing liquid is coated onto the exposed first coating layer to form a second coating layer which exhibits a refractive index lower than a refractive index of the first coating layer, and
- a baking step in which the panel portion on which the second coating layer is formed is baked.
Dependencies are inferred from the claim text.