Patent US5966394A successfully refreshed from Google Patents.
US5966394A
Expired / Lapsed
US
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Laser diode controller
Assignee: Eastman Kodak Co
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Filing: 1997-05-30
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Granted: 1999-10-12
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Expires: 2017-05-30
Abstract
Abstract A laser diode controller (30) having a constant current source (60) which supplies current to a laser diode (90) is disclosed. A current shunt switch (40) directs current to either the laser diode (90) or to a bypass circuit (42). A thermal compensator (70) alters a current level of the constant current source (60) as a function of on-time of the laser diode (90) to compensate for changes in optical power conversion efficiency due to temperature changes in the laser diode. A thermo electric cooler controller (80) maintains a constant temperature of a substrate on which the laser diode is mounted. In one embodiment, an array of sample and hold amplifiers (50) eliminates a need for multiple DACs.
Inventors
- 👤 Robert W. Spurr
- 👤 Seung H. Baek
- 👤 Thomas A. Mackin
- 👤 William R. Markis
- 👤 Kurt M. Sanger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:49
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/04; H01S5/042; H01S5/02; H01S5/024; H01S5/02407; H01S5/02415; H01S5/0428
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
93 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode; and a thermo electric cooler controller which maintains a constant temperature of a substrate for said laser diode.
Claim 2
Dependent Claim
93 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode; and a thermo electric cooler controller which maintains a constant temperature of a substrate for said laser diode.
Claim 3
Dependent Claim
31 words
A laser diode controller as in claim 1 wherein said constant current source is connected to a system ground and said current shunt switch is connected to a laser power supply.
Claim 4
Dependent Claim
31 words
A laser diode controller as in claim 1 wherein said current shunt switch is connected to a system ground and said constant current source is connected to a laser power supply.
Claim 5
Dependent Claim
30 words
A laser diode controller as in claim 1 wherein said thermo electric cooler controller receives input from a temperature sensor and provides a signal to a thermal electric cooler (TEC).
Claim 6
Dependent Claim
35 words
A laser diode controller as in claim 1 wherein said constant current source, said current shunt switch, said thermal compensator, and said thermo electric cooler controller are contained on an application specific integrated circuit (ASIC).
Claim 7
Dependent Claim
41 words
A laser diode controller as in claim 5 wherein said ASIC contains an array of sample and hold amplifiers which provides analog setpoints for said constant current source, said current shunt switch, said thermal compensator, and said thermo electric cooler controller.
Claim 8
Dependent Claim
26 words
A laser diode controller as in claim 1 wherein said current shunt switch is capable of switching a two amp current in less than 20 nanoseconds.
Claim 9
Dependent Claim
22 words
A laser diode controller as in claim 1 wherein said laser diode controller is incorporated in a multiple channel laser printing system.
Claim 10
Dependent Claim
20 words
A laser diode controller as in claim 1 wherein said laser diode controller is incorporated in a thermal printing system.
Claim 11
Dependent Claim
23 words
A laser diode controller as in claim 1 wherein said laser diode controller is incorporated in a printing system with an internal drum.
Claim 12
Dependent Claim
23 words
A laser diode controller as in claim 1 wherein said laser diode controller is incorporated in a printing system with an external drum.
Claim 13
Dependent Claim
28 words
A laser diode controller as in claim 1 wherein said thermal compensator has a plurality of filter stages to provide a constant optical power output as temperature changes.
Claim 14
Dependent Claim
21 words
A laser diode controller as in claim 12 wherein each of said filter stages has a RC circuit providing time constants.
Claim 15
Dependent Claim
122 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode; a laser diode temperature controller which maintains a constant temperature of a substrate for said laser diode; and an array of sample and hold amplifiers which provides analog setpoints for said constant current source, said current shunt switch, said thermal compensator, and said laser diode temperature controller.
Claim 16
Dependent Claim
122 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode; a laser diode temperature controller which maintains a constant temperature of a substrate for said laser diode; and an array of sample and hold amplifiers which provides analog setpoints for said constant current source, said current shunt switch, said thermal compensator, and said laser diode temperature controller.
Claim 17
Dependent Claim
26 words
A laser diode controller as in claim 14 wherein said laser diode temperature controller is comprised of a temperature sensor and a thermal electric cooler (TEC).
Claim 18
Dependent Claim
35 words
A laser diode controller as in claim 14 wherein said constant current source, said current shunt switch, said thermal compensator, and said laser diode temperature controller are contained on an application specific integrated circuit (ASIC).
Claim 19
Dependent Claim
19 words
A laser diode controller as in claim 16 wherein said ASIC contains said array of sample and hold amplifiers.
Claim 20
Dependent Claim
26 words
A laser diode controller as in claim 14 wherein said current shunt switch is capable of switching a two amp current in less than 25 nanoseconds.
Claim 21
Dependent Claim
22 words
A laser diode controller as in claim 14 wherein said laser diode controller is incorporated in a multiple channel laser printing system.
Claim 22
Dependent Claim
20 words
A laser diode controller as in claim 14 wherein said laser diode controller is incorporated in a thermal printing system.
Claim 23
Dependent Claim
23 words
A laser diode controller as in claim 14 wherein said laser diode controller is incorporated in a printing system with an internal drum.
Claim 24
Dependent Claim
23 words
A laser diode controller as in claim 14 wherein said laser diode controller is incorporated in a printing system with an external drum.
Claim 25
Dependent Claim
24 words
A laser diode controller as in claim 14 wherein said thermal compensator is programmed to provide a constant optical power output as temperature changes.
Claim 26
Dependent Claim
18 words
A laser diode controller as in claim 14 wherein said thermal compensator is programmed with multiple time constants.
Claim 27
Dependent Claim
76 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; and a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode.
Claim 28
Dependent Claim
76 words
A laser diode controller comprising: a constant current source wherein said constant current source supplies current to a laser diode; a current shunt switch which directs current to either said laser diode or to a bypass circuit; and a thermal compensator which alters a level of said constant current source as a function of on-time of said laser diode to compensate for changes in optical power conversion efficiency due to temperature changes in said laser diode.
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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) | 2002-10-11 | 2003-04-12 | 2003-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-11 | 2007-04-12 | 2007-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-11 | 2011-04-12 | 2011-10-12 | $7700.00 | Window Closed / Lapsed |