Patent US3696404A successfully refreshed from Google Patents.
US3696404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog-to-digital converter
Assignee: Individual
•
Filing: 1969-03-27
•
Granted: 1972-10-03
•
Expires: 1989-03-27
Abstract
Abstract Described is an analog-to-digital converter of the type in which a laser beam is modulated with an analog signal and the resulting modulated beam partially transmitted and partially reflected by a series of plates. Separate photodiode detectors are positioned behind each plate to sense the transmitted light and furnish digital inputs to suitable encoding circuitry. As the intensity of the beam increases due to an increase in the analog value of the input signal, greater numbers of the diode detectors are triggered to reflect an increase in the digital value also.
Inventors
- 👤 Gideon R Brainerd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:17
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/34; H03M1/36; H03M1/361
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
173 words
An analog-to-digital converter comprising means for producing a beam of coherent light, an electro-optical modulator in the path of said beam of coherent light for varying the intensity of said beam as a function of an applied analog signal, a plurality of partially reflecting and partially transmitting mirrors in the path of said beam after it passes through said electro-optical modulator, a light sensitive switch device on the sides of the respective mirrors opposite from the incident light on each of said mirrors, each of said switch devices being actuated when the intensity of the light passing through its associated mirror exceeds a predetermined level, and means including electrical circuit apparatus connected to said switch devices for indicating the number of switch devices which have been actuated, the arrangement being such that as the magnitude of said analog signal increases, the intensity of said coherent light beam also increases as do the number of said switch devices which are activated to indicate in digital form an increase in magnitude in said analog signal.
Claim 2
Dependent Claim
173 words
An analog-to-digital converter comprising means for producing a beam of coherent light, an electro-optical modulator in the path of said beam of coherent light for varying the intensity of said beam as a function of an applied analog signal, a plurality of partially reflecting and partially transmitting mirrors in the path of said beam after it passes through said electro-optical modulator, a light sensitive switch device on the sides of the respective mirrors opposite from the incident light on each of said mirrors, each of said switch devices being actuated when the intensity of the light passing through its associated mirror exceeds a predetermined level, and means including electrical circuit apparatus connected to said switch devices for indicating the number of switch devices which have been actuated, the arrangement being such that as the magnitude of said analog signal increases, the intensity of said coherent light beam also increases as do the number of said switch devices which are activated to indicate in digital form an increase in magnitude in said analog signal.
Claim 3
Dependent Claim
16 words
The analog-to-digital converter of claim 1 wherein said light sensitive switches comprise light sensitive semiconductive diodes.
Claim 4
Dependent Claim
35 words
The analog-to-digital converter of claim 2 wherein each of said light sensitive diodes is connected to an associated multivibrator which is switched from one stable state to another when its associated light sensitive diode conducts.
Claim 5
Dependent Claim
27 words
The analog-to-digital converter of claim 3 including biasing networks for each of said diodes whereby the light level at whicH a diode is actuated can be varied.
Claim 6
Dependent Claim
17 words
The analog-to-digital converter of claim 1 wherein the transmissivity of each of said mirrors is the same.
Claim 7
Dependent Claim
16 words
The analog-to-digital converter of claim 1 including a laser for producing said beam of coherent light.
Claim 8
Dependent Claim
16 words
The analog-to-digital converter of claim 1 wherein said electro-optical modulator includes a pair of birefringent crystals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |