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US4803337A
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Method for producing a light transmitting filter
Assignee: Sony Corp
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Filing: 1987-11-25
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Granted: 1989-02-07
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Expires: 2007-11-25
Abstract
Abstract A method for the preparation of an illuminance-correcting light transmitting filter employed in an exposure device adapted for the preparation of the phosphor screen of the color cathode ray tube. The laser light modulated with a light modulator is radiated to the surface of the filter base plate on which a thin layer of the recording material is previously formed. A pattern of through-holes of variable size or density is formed as the thin layer is vaporized so that the light transmitting filter may be prepared with high accuracy and in a shorter time. The laser light is modified with the light modulator, and the filter base plate is securely mounted to a movable stage, the movement of which in the X- and Y- directions is controlled under the commands of a computer unit.
Inventors
- 👤 Reiji Ishikawa
- 👤 Tomohiro Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:00
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/22; C03C17/06; G; G02; G02B; G02B5/00; G02B5/20; G02B5/205; C03C2217/00; C03C2217/20; C03C2217/25; C03C2217/257; C03C2217/26; C03C2217/27; C03C2217/28; C03C2217/287; C03C2217/289; C03C2218/00; C03C2218/30; C03C2218/32; C03C2218/328
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
A method of producing a selective light transmitting filter for illuminance correction purposes in an exposure device adaptive for producing a phosphor screen of a cathode ray tube, comprising the steps of: forming an opaque layer of heat mode optical recording material on a flat transparent base plate; modulating a laser beam by an optical modulator operated by voltage pulses a pulse width or period of repetition of which is preset by the pattern to be formed in said layer; and irradiating and applying said pulses of said modulated laser beam on said layer while moving said beam plate in perpendicular directions in the same plane for evaporating selected desired portions of said layer to produce a predetermined, varying pattern of light transmitting through-holes in said layer on said base plate in accordance with said predetermined light transmittance pattern.
Claim 2
Independent Claim
139 words
A method of producing a selective light transmitting filter for illuminance correction purposes in an exposure device adaptive for producing a phosphor screen of a cathode ray tube, comprising the steps of: forming an opaque layer of heat mode optical recording material on a flat transparent base plate; modulating a laser beam by an optical modulator operated by voltage pulses a pulse width or period of repetition of which is preset by the pattern to be formed in said layer; and irradiating and applying said pulses of said modulated laser beam on said layer while moving said beam plate in perpendicular directions in the same plane for evaporating selected desired portions of said layer to produce a predetermined, varying pattern of light transmitting through-holes in said layer on said base plate in accordance with said predetermined light transmittance pattern.
Claim 3
Dependent Claim
15 words
The method according to claim 1, in which said base plate is a glass plate.
Claim 4
Dependent Claim
15 words
The method according to claim 1, in which said base plate is a quartz plate.
Claim 5
Dependent Claim
16 words
The method according to claim 1, in which said base plate is an acrylic resin plate.
Claim 6
Dependent Claim
15 words
The method according to claim 1, in which said layer is formed of tellurium (Te).
Claim 7
Dependent Claim
15 words
The method according to claim 1, in which said layer is formed of chromium (Cr).
Claim 8
Dependent Claim
25 words
The method according to claim 1, in which said layer is selected from the group of TeCu, TeC, AsTe, AsSeTe, TeOx, Bi, Ni and TeSe.
Claim 9
Dependent Claim
40 words
The method according to claim 1, in which the intensity of said laser beam is constant and the pulse width of the voltage applied to said optical modulator is changed so that the length of said light-transmitting through-hole is changed.
Claim 10
Dependent Claim
39 words
The method according to claim 1, in which the diameter of said light-transmitting through-hole is constant and the number of the pulses applied to said optical modulator is changed so that the density distribution of said through-hole is changed.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-07 | 1992-08-08 | 1993-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-07 | 1996-08-08 | 1997-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-07 | 2000-08-08 | 2001-02-07 | $7700.00 | Window Closed / Lapsed |