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USH322H
Expired / Lapsed
US
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Laser diode power controller
Assignee: United States, SUBJECT TO A NONEXCLUSIVE AND ROYALTY-FREE LICENSE WHICH IS HEREBY RESERVED TO CONTRACTOR
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Filing: 1985-07-22
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Granted: 1987-08-04
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Expires: 2005-07-22
Abstract
Abstract A laser diode power supply that uses a proportional controller that drives series pass transistor to regulate laser diode current and the intensity of the laser diode output. The purpose of the controller is to maintain constant laser output power when its unregulated output power would otherwise gradually decrease with age. The laser diode includes a detector that samples light emitted from the laser diode. The output of the detector is amplified and compared to a reference voltage in an integrator. The output of the integrator controls a series pass transistor that varies to power to the laser diode to provide a constant laser diode power output. The controller also includes power limiting and transient voltage protection circuits.
Inventors
- 👤 Brent S. Simons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:00
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/06825
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
A power supply controller for a laser diode including: (a) a detector for receiving light emitted from the back facet of the laser diode; (b) an amplifier, an integrator, a reference voltage generator, a power source and a series pass transistor; (c) the output of said detector being applied to the input of said amplifier, the output of said amplifier being applied to a first input of said integrator, the output of said reference voltage generator being applied to a second input of said integrator, the output of said integrator being applied to the base of said series pass transistor, the output of said power source being passed through said series pass transistor to the power input of said laser diode; whereby (d) the voltage output of said reference voltage generator is selected to establish a preselected output power from said laser diode and said integrator provides an output signal to said series pass transistor to adjust the power applied to the power input of said laser diode to maintain constant laser output power.
Claim 2
Dependent Claim
174 words
A power supply controller for a laser diode including: (a) a detector for receiving light emitted from the back facet of the laser diode; (b) an amplifier, an integrator, a reference voltage generator, a power source and a series pass transistor; (c) the output of said detector being applied to the input of said amplifier, the output of said amplifier being applied to a first input of said integrator, the output of said reference voltage generator being applied to a second input of said integrator, the output of said integrator being applied to the base of said series pass transistor, the output of said power source being passed through said series pass transistor to the power input of said laser diode; whereby (d) the voltage output of said reference voltage generator is selected to establish a preselected output power from said laser diode and said integrator provides an output signal to said series pass transistor to adjust the power applied to the power input of said laser diode to maintain constant laser output power.
Claim 3
Dependent Claim
50 words
The controller of claim 1 including: (a) a regulator operably connected between said power source and said series pass transistor, said regulator being responsive to a laser enable signal and providing a slow increase of turn-on power and a slow decrease of turn-off power in response to said enable signal.
Claim 4
Dependent Claim
42 words
The controller of claim 2 including: (a) a current sensing device operably connected between said series pass transistor and said laser diode and having its output connected to an input of said regulator to limit the maximum power applied to said laser.
References Cited (Backward Citations)
US4305047A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-03 | 1991-02-02 | 1991-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-03 | 1995-02-02 | 1995-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-03 | 1999-02-02 | 1999-08-04 | $7700.00 | Window Closed / Lapsed |