US4345330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser energy control circuit
Assignee: Ferranti International PLC
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Filing: 1980-04-14
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Granted: 1982-08-17
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Expires: 2000-04-14
Abstract
Abstract A laser energy control circuit for a gas-discharge excited laser includes an energy source PSU to supply energy to the gas discharge. First circuit means TR1, TR2 operate to limit the energy supplied to a first value for a first time interval, after which second circuit means A1, A2 allow the energy to rise to a maximum value and then decrease gradually to a second value over a second time interval. Subsequently, third circuit means including amplifiers A3 to A6 operate to maintain the light output of the laser at a desired value.
Inventors
- 👤 James B. Howie
- 👤 John McLeod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:30
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/091; H01S3/0915; H01S3/092; H01S3/10; H01S3/13; H01S3/131; H01S3/134
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
203 words
A laser energy control circuit for a gas-discharge-excited laser, which includes an energy source arranged to supply energy to the gas discharge at a rate determined by a control voltage, a first circuit connected to said source and arranged to deliver a first control voltage of such a value that the energy supplied is limited to a first value for a first time interval after initiation of the gas discharge, a second circuit connected to said source and arranged to deliver a second control voltage such that said energy supplied increases to a maximum value at the end of said first time interval and subsequently to change the control voltage in such a manner that said energy supplied is decreased gradually from said maximum value to a running value during a second time interval following said first time interval, a timing arrangement responsive to a series of clock pulses to determine the duration of said first time interval, and a third circuit connected to said source and responsive to light output of the laser after said second time interval to vary said control voltage in such a manner that said energy supplied is controlled to maintain said light output of the laser constant.
Claim 2
Dependent Claim
203 words
A laser energy control circuit for a gas-discharge-excited laser, which includes an energy source arranged to supply energy to the gas discharge at a rate determined by a control voltage, a first circuit connected to said source and arranged to deliver a first control voltage of such a value that the energy supplied is limited to a first value for a first time interval after initiation of the gas discharge, a second circuit connected to said source and arranged to deliver a second control voltage such that said energy supplied increases to a maximum value at the end of said first time interval and subsequently to change the control voltage in such a manner that said energy supplied is decreased gradually from said maximum value to a running value during a second time interval following said first time interval, a timing arrangement responsive to a series of clock pulses to determine the duration of said first time interval, and a third circuit connected to said source and responsive to light output of the laser after said second time interval to vary said control voltage in such a manner that said energy supplied is controlled to maintain said light output of the laser constant.
Claim 3
Dependent Claim
19 words
A circuit as claimed in claim 1 in which said clock pulses are trigger pulses of a pulsed laser.
Claim 4
Dependent Claim
31 words
A circuit as claimed in claim 1 in which said first circuit comprises a switch operable during said first time interval to apply a first control signal to the energy source.
Claim 5
Dependent Claim
26 words
A circuit as claimed in claim 3 in which said first circuit includes a circuit element operable to change the value of said first control voltage.
Claim 6
Dependent Claim
39 words
A circuit as claimed in claim 1 in which said second circuit comprises an integrator to apply to said energy source a second control voltage to define a rate at which said energy supplied decreases to said running value.
Claim 7
Dependent Claim
26 words
A circuit as claimed in claim 5 in which said second circuit includes a circuit element operable to change said running value of said energy supplied.
Claim 8
Dependent Claim
28 words
A circuit as claimed in claim 5 in which said rate at which said energy supplied decreases may be varied by varying a time constant of the integrator.
Claim 9
Dependent Claim
23 words
A circuit as claimed in claim 1 in which said third circuit includes a light-sensitive device responsive to the light output of laser.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-16 | 1986-02-15 | 1986-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-16 | 1990-02-15 | 1990-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-16 | 1994-02-15 | 1994-08-17 | $7700.00 | Window Closed / Lapsed |