Patent US3407024A successfully refreshed from Google Patents.
Patent US4275404A successfully refreshed from Google Patents.
US4275404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monolithic opto-isolator
Assignee: AT&T Inc
•
Filing: 1979-10-05
•
Granted: 1981-06-23
•
Expires: 1999-10-05
Abstract
Abstract A monolithic opto-isolator is fabricated on an insulating substrate by using a graded bandgap semiconductor material for the LED and photodetector and spacing the LED from the photodetector with insulating channels.
Inventors
- 👤 Daniel R. Cassiday
- 👤 Vassilis G. Keramidas
- 👤 Ronald J. Roedel
- 👤 Robert H. Saul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:57
CPC Classifications
H; H10; H10F; H10F55/00; H10F55/20; H10F55/25; H10F55/255
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
147 words
An opto-isolator comprising an insulating substrate; a light emitting diode disposed on said substrate, said light emitting diode consisting of a semiconductor material and having a first conductivity type region and a second conductivity type region, said regions forming a first p-n junction; a photodetector disposed on said substrate, said photodetector consisting of a said semiconductor material and having a first conductivity type region and a second conductivity type region, said regions forming a second p-n junction, said photodetector spaced from said light emitting diode by a channel; electrical contacts to said first and second conductivity type regions of said light emitting diode and electrical contacts to said first and second conductivity type regions of said photodetector; characterized in that said semiconductor material has a graded bandgap, and said photodetector and said light emitting diode are optically coupled by said channel, said channel extending into said substrate.
Claim 2
Dependent Claim
147 words
An opto-isolator comprising an insulating substrate; a light emitting diode disposed on said substrate, said light emitting diode consisting of a semiconductor material and having a first conductivity type region and a second conductivity type region, said regions forming a first p-n junction; a photodetector disposed on said substrate, said photodetector consisting of a said semiconductor material and having a first conductivity type region and a second conductivity type region, said regions forming a second p-n junction, said photodetector spaced from said light emitting diode by a channel; electrical contacts to said first and second conductivity type regions of said light emitting diode and electrical contacts to said first and second conductivity type regions of said photodetector; characterized in that said semiconductor material has a graded bandgap, and said photodetector and said light emitting diode are optically coupled by said channel, said channel extending into said substrate.
Claim 3
Dependent Claim
28 words
An opto-isolator as recited in claim 1 in which said semiconductor is selected from the group consisting of Group II-VI compounds and Group III-V compounds and mixtures thereof.
Claim 4
Dependent Claim
40 words
An opto-isolator as recited in claim 2 in which said semiconductor material comprises Ga 1-x Al x As, x varying monotonically from a value greater than or equal to 0.0 to a value less than or equal to approximately 0.3.
Claim 5
Dependent Claim
20 words
An opto-isolator as recited in claim 3 in which said substrate has a resistivity of at least 10 4 ohm.cm.
Claim 6
Dependent Claim
27 words
An opto-isolator as recited in claim 1 or 4 in which said distance between said photodetector and said light emitting diode is between 25 and 75 microns.
Claim 7
Dependent Claim
29 words
An opto-isolator as recited in claim 2 or 4 in which said semiconductor material has the approximate composition Ga 0 .92 Al 0 .08 As at said p-n junction.
References Cited (Backward Citations)
US4136928A
Cited
US4152044A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |