Patent US3760698A successfully refreshed from Google Patents.
US3760698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light exposure apparatus for forming fluorescent screens of color picture tubes
Assignee: Mitsubishi Electric Corp
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Filing: 1971-10-04
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Granted: 1973-09-25
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Expires: 1991-10-04
Abstract
Abstract The disclosed apparatus includes a point source of light irradiating progressively the face plate for shadow mask color picture tubes from one end to the other through a slit on a douser reciprocating in parallel with the face plate. For forming phosphor dots of the particular color, the slit elongates in a direction to displace the corresponding gun from the tube axis and reciprocates perpendicularly to that direction at a higher rate for the central portion than for the lateral edge portions of the face plate. In synchronization with the movement of the slit, the light source depicts a closed curve as determined by the shape and speed of movement of the slit.
Inventors
- 👤 T Fujimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:02
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/20; H01J9/22; H01J9/227; H01J9/2271; H01J9/2272
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
183 words
In a light exposure apparatus for forming a fluorescent screen of a color television shadow mask picture tube, said screen being formed from a face plate for the color picture tube having a light sensitive layer containing phosphors coated on its internal surface and wherein a shadow mask is positioned opposite said internal surface of said face plate, the improvement comprising a point source of light disposed on that side of said shadow mask remote from said face plate, a movable light shading plate dsposed between said point source of light and said shadow mask, a strip-shaped slit disposed in said light shading plate, and means for reciprocating said light shading plate in substantially parallel relationship with respect to said internal surface of said face plate, so that a beam of light emitted from said point source of light falls upon the said internal surface of said face plate through said slit on the moving light shading plate to irradiate progressively the internal surface of the face plate in a shape similar to that of the slit from one end to the other.
Claim 2
Dependent Claim
183 words
In a light exposure apparatus for forming a fluorescent screen of a color television shadow mask picture tube, said screen being formed from a face plate for the color picture tube having a light sensitive layer containing phosphors coated on its internal surface and wherein a shadow mask is positioned opposite said internal surface of said face plate, the improvement comprising a point source of light disposed on that side of said shadow mask remote from said face plate, a movable light shading plate dsposed between said point source of light and said shadow mask, a strip-shaped slit disposed in said light shading plate, and means for reciprocating said light shading plate in substantially parallel relationship with respect to said internal surface of said face plate, so that a beam of light emitted from said point source of light falls upon the said internal surface of said face plate through said slit on the moving light shading plate to irradiate progressively the internal surface of the face plate in a shape similar to that of the slit from one end to the other.
Claim 3
Dependent Claim
63 words
A light exposure apparatus as claimed in claim 1 wherein said light shading plate is positioned with respect to said face plate so that said slit elongates in the direction in which the electron beam source for stimulating the particular phosphor portion being formed on said internal suface of said face plate is displaced from the longitudinal axis of the color picture tube.
Claim 4
Dependent Claim
82 words
A light exposure apparatus as claimed in claim 1 wherein said strip-shaped slit on said light shading plate has a width which increases from a small value at the center to a large value at each end thereof and wherein means are provided to move said light shading plate perpendicular to the lengthwise direction of said slit such that the slit is moved at a higher rate for the central portion of the face plate than for the lateral edge portion thereof.
Claim 5
Dependent Claim
44 words
A light exposure apparatus as claimed in claim 1, wherein a correction lens is disposed between said point source of light and said light shading plate for controlling the optical path along which the beam of light from the point source of light travels.
Claim 6
Dependent Claim
42 words
A light exposure apparatus as claimed in claim 1, wherein a correction lens is disposed between said light shading plate and said shadow mask for controlling the optical path along which the beam of light from the point source of light travels.
Claim 7
Dependent Claim
29 words
A light exposure apparatus as claimed in claim 1, further comprising means for moving said point source of light in synchronization with the movement of said light shading plate.
Claim 8
Dependent Claim
63 words
A light exposure apparatus as claimed in claim 1, wherein said means for reciprocating the light shading plate includes a cam mechanism for reciprocating the light shading plate and another cam mechanism for moving said point source of light along a predetermined closed curve in synchronization with the movement of said light shading means, both cam mechanisms being mounted on a common shaft.
References Cited (Backward Citations)
US3259038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |