US4021375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating polycrystalline selenium imaging devices
Assignee: RCA Corp
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Filing: 1975-09-15
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Granted: 1977-05-03
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Expires: 1995-09-15
Abstract
Abstract A photoconductive target for a vidicon-type camera tube, which includes a layer of polycrystalline selenium, is exposed to a diffusion cycle wherein the temperature is gradually increased from an initial baking temperature of about 50° C. to a final baking temperature of about 150° C. at a rate of about 5° C. per minute. Thereafter the target is baked at a temperature of about 100° C. for about 16 hours in oxygen to substantially reduce the dark current of the target.
Inventors
- 👤 Robert Milton Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:09
CPC Classifications
H; H10; H10F; H10F77/00; H10F77/10; H10F77/12; H10F77/121; H10F77/1215; H01; H01J; H01J9/00; H01J9/20; H01J9/233; Y; Y10; Y10S; Y10S257/00; Y10S257/917
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
In a method of fabricating a photoconductive imaging body having a supported layer of hexagonal selenium selenium in contact with a material at least partially containing thallium, the improvement comprising, baking said body at an initial temperature less than about 60° C. in an atmosphere containing air or oxygen for at least 15 minutes, gradually increasing the temperature to a final temperature between about 140° C. and about 180° C.; and baking at the final temperature for at least 15 minutes, whereby thallium is diffused into said selenium layer.
Claim 2
Dependent Claim
89 words
In a method of fabricating a photoconductive imaging body having a supported layer of hexagonal selenium selenium in contact with a material at least partially containing thallium, the improvement comprising, baking said body at an initial temperature less than about 60° C. in an atmosphere containing air or oxygen for at least 15 minutes, gradually increasing the temperature to a final temperature between about 140° C. and about 180° C.; and baking at the final temperature for at least 15 minutes, whereby thallium is diffused into said selenium layer.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said thallium or thallium containing material comprises Tl 2 Se 3 or Tl 2 Se.
Claim 4
Dependent Claim
21 words
The method of claim 2 wherein said material at least partially containing thallium contacts opposite major surfaces of said selenium layer.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein said temperature between said initial and final temperatures is gradually increased at a rate of about 5° C. per minute.
Claim 6
Dependent Claim
11 words
The method of claim 4, wherein said atmosphere includes water vapor.
Claim 7
Dependent Claim
54 words
The method of claim 1, including the step of anneal baking said body in an atmosphere comprising air or oxygen at a temperature of from about 80° C. to about 120° C. for a period of time necessary to decrease the dark current associated with the body by a factor of two or three.
Claim 8
Dependent Claim
17 words
The method of claim 6, wherein said atmosphere of all baking steps includes oxygen and water vapor.
References Cited (Backward Citations)
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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) | 1980-05-02 | 1980-11-01 | 1981-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-02 | 1984-11-01 | 1985-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-02 | 1988-11-01 | 1989-05-03 | $7700.00 | Window Closed / Lapsed |