US3836797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic intensity control for electronic displays
Assignee: Collins Radio Co
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Filing: 1973-10-29
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Granted: 1974-09-17
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Expires: 1993-10-29
Abstract
Abstract A pulsed waveform generation means with duty-cycle a function of ambient light intensity utilizes multivibrator means including a photo resistor to vary coupling time constant such that on-time half-cycle durations vary with ambient light. The waveform is usable in conjunction with bi-level logic means to apply power on a variable duty-cycle pulsed bias to indicator or annunciator lamps.
Inventors
- 👤 C Steen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:49
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
An intensity control circuit for controlling the illumination intensity of a lighted indicating means as a direct function of ambient light intensity, comprising a multivibrator, means for controlling the time duration of first alternate half-cycles of the output from said multivibrator as a direct function of ambient light intensity, said multivibrator comprising an RC time constant means the resistance parameter of which comprises a photo resistor connected in shunt with a fixed resistance member, said RC time constant means defining the time duration of said first alternate half-cycles, and means for energizing said lighted indicating means on a duty cycle basis as defined by second alternate half-cycles of the output from said multivibrator.
Claim 2
Dependent Claim
113 words
An intensity control circuit for controlling the illumination intensity of a lighted indicating means as a direct function of ambient light intensity, comprising a multivibrator, means for controlling the time duration of first alternate half-cycles of the output from said multivibrator as a direct function of ambient light intensity, said multivibrator comprising an RC time constant means the resistance parameter of which comprises a photo resistor connected in shunt with a fixed resistance member, said RC time constant means defining the time duration of said first alternate half-cycles, and means for energizing said lighted indicating means on a duty cycle basis as defined by second alternate half-cycles of the output from said multivibrator.
Claim 3
Dependent Claim
122 words
Waveform generating means comprising first and second monostable multivibrators each, in response to a triggering input thereto, developing an output pulse of a predetermined time duration, means coupling the output of each monostable multivibrator as a triggering input to the other of said monostable multivibrators, the output of one of said monostable multivibrators comprising the output of said waveform generating means and having a duty cycle on-time defined by the design on-time of one of said monostable multivibrators and a duty cycle off-time defined by the design on-time of the other one of said monostable multivibrators, the on-time of one of said monostable multivibrators being selectively variable, and control means whereby said selectively variable on-time is directly proportional to ambient light intensity.
Claim 4
Dependent Claim
122 words
Waveform generating means comprising first and second monostable multivibrators each, in response to a triggering input thereto, developing an output pulse of a predetermined time duration, means coupling the output of each monostable multivibrator as a triggering input to the other of said monostable multivibrators, the output of one of said monostable multivibrators comprising the output of said waveform generating means and having a duty cycle on-time defined by the design on-time of one of said monostable multivibrators and a duty cycle off-time defined by the design on-time of the other one of said monostable multivibrators, the on-time of one of said monostable multivibrators being selectively variable, and control means whereby said selectively variable on-time is directly proportional to ambient light intensity.
Claim 5
Dependent Claim
46 words
Waveform generating means as defined in claim 2 wherein said one of said monostable multivibrators comprises an RC time constant means defining the on-time thereof, and means for controlling the resistance parameter of said RC time constant means as a direct function of ambient light intensity.
Claim 6
Dependent Claim
21 words
Waveform generating means as defined in claim 3 wherein said resistance parameter comprises a photo resistor shunting a fixed resistance member.
Claim 7
Dependent Claim
165 words
An intensity control for controlling the intensity of a lighted indicating means as a direct function of ambient light intensity, comprising waveform generating means, said waveform generating means comprising first and second monostable multivibrators each, in response to a triggering input thereto, developing an output pulse having a predetermined time duration, means coupling the output of said monostable multivibrators, multivibrator as a triggering input to the other of said monostable multivibrators, the output of one of said monostable multivibrators comprising the output of said waveform generating means and having a duty cycle on-time defined by the design on-time of one of said monostable multivibrators and a duty cycle off-time defined by the design on-time of the other of said multivibrators, means for controlling the on-time of one of said monostable multivibrators as a direct function of ambient light intensity, and means for energizing said lighted indicating means on a duty cycle basis as defined by the on-time of the other one of said monostable multivibrators.
Claim 8
Dependent Claim
165 words
An intensity control for controlling the intensity of a lighted indicating means as a direct function of ambient light intensity, comprising waveform generating means, said waveform generating means comprising first and second monostable multivibrators each, in response to a triggering input thereto, developing an output pulse having a predetermined time duration, means coupling the output of said monostable multivibrators, multivibrator as a triggering input to the other of said monostable multivibrators, the output of one of said monostable multivibrators comprising the output of said waveform generating means and having a duty cycle on-time defined by the design on-time of one of said monostable multivibrators and a duty cycle off-time defined by the design on-time of the other of said multivibrators, means for controlling the on-time of one of said monostable multivibrators as a direct function of ambient light intensity, and means for energizing said lighted indicating means on a duty cycle basis as defined by the on-time of the other one of said monostable multivibrators.
Claim 9
Dependent Claim
47 words
An intensity control circuit as defined in claim 5 where said one of said monostable multivibrators comprises an RC time contant means defining the on-time thereof and means for controlling the resistance parameter of said RC time constant means as A direct function of ambient light intensity.
Claim 10
Dependent Claim
21 words
An intensity control circuit as defined in claim 6 wherein said resistance parameter comprises a photo resistor shunting fixed resistance member.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |