US4584687A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calibrated feedback for laser diodes
Assignee: Philips North America LLC
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Filing: 1983-12-12
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Granted: 1986-04-22
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Expires: 2003-12-12
Abstract
Abstract Two thick film resistors calibrate the output of the feedback light detector circuit for monitoring the light power of a laser diode. The output is connected to the power control circuit for the laser diode. Calibration of the feedback output during manufacture permits replacement of the laser diode/feedback light detector combination in the field without recalibration of the power control circuit.
Inventors
- 👤 P. Guy Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:14
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/126; H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
A method of calibrating the feedback output from the feedback light detector of the laser diode of an optical disk drive of a laser light pen comprising; mounting a first and a second resistor in a laser light pen; connecting said first resistor between the feedback light detector and ground; connecting said second resistor between the feedback light detector and a feedback output; operating the laser diode to produce a predetermined light power output; adjusting the resistance of the first resistor to produce a predetermined voltage at the feedback output; and adjusting the resistance of the second resistor to produce a predetermined impedance at the feedback output.
Claim 2
Independent Claim
107 words
A method of calibrating the feedback output from the feedback light detector of the laser diode of an optical disk drive of a laser light pen comprising; mounting a first and a second resistor in a laser light pen; connecting said first resistor between the feedback light detector and ground; connecting said second resistor between the feedback light detector and a feedback output; operating the laser diode to produce a predetermined light power output; adjusting the resistance of the first resistor to produce a predetermined voltage at the feedback output; and adjusting the resistance of the second resistor to produce a predetermined impedance at the feedback output.
References Cited (Backward Citations)
US3290516A
Cited
US4243972A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |