US5260563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compact laser warning receiver
Assignee: Bankers Trust Co
•
Filing: 1992-11-09
•
Granted: 1993-11-09
•
Expires: 2012-11-09
Abstract
Abstract A portable laser pulse detection device. Optical pulses are sensed by a photodiode, and if the pulse width is narrow enough to yield sufficient spectral energy within the bandpass of the tuned circuits, a "laser occurred" indication will be produced by the processing circuitry. Automatic adjustment of the detected output for non-laser incident radiation is made by varying the signal level into a sequential detection logarithmic amplifier by a voltage proportional to the integral of the incident radiation over a short period of time. The device is shielded against electromagnetic interference and adapts automatically to variations in background noise.
Inventors
- 👤 Reginald W. Hunter
- 👤 Gerald D. Powell
- 👤 Ronald E. Ham
- 👤 Joseph Lenhardt
- 👤 Thomas G. Ratliff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:33
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/4804; G01D; G01D3/00; G01D3/08; G08; G08B; G08B21/00; G08B21/18; G08B21/182
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
447 words
A compact laser warning receiver for detecting a laser pulse having a laser pulse width and a laser pulse rise time, said laser warning receiver comprising: a case, to which said laser pulse and ambient light are applied, said ambient light having a variable level of intensity; a conductor assembly adapted to receive said laser pulse and said ambient light, said conductor assembly further adapted to conduct said laser pulse and said ambient light from the exterior to the interior of said case; a photoelectric transducer disposed within said case and responsive to said laser pulse received from said conductor assembly to generate a first electrical signal having an energy content and having a first signal pulse width and a first signal rise time, respectively, corresponding to said laser pulse width and said laser pulse rise time, said first signal pulse width and first signal rise time collectively providing an indication of energy content of said first electrical signal; said photoelectric transducer further responsive to said ambient light received from said conductor assembly to produce a second electrical signal having a current level corresponding to said variable ambient light; a resonant circuit, having a resonant frequency, said resonant circuit coupled inductively to said photoelectric transducer and producing an output signal having a voltage level proportional to said energy content of said first signal; an integrating circuit coupled in series with said photoelectric transducer, said integrating circuit providing a direct current path for said second electrical signal from said photoelectric transducer and further providing a high-voltage short-circuit at said resonant frequency, and producing an integrating circuit output signal having a variable voltage proportional to the integral of said variable ambient light level over a predetermined integration time interval; a high-frequency amplifier coupled to said resonant circuit and responsive to said resonant circuit output signal to produce an amplified resonant circuit output signal; a gain control amplifier coupled to said integrating circuit and responsive to said integrating circuit output signal to produce a gain control signal; a variable gain amplifier, coupled to said high-frequency amplifier and said gain control amplifier and responsive to said gain control signal to amplify said amplified resonant circuit output signal by a gain factor determined by said gain control signal, thereby producing a variable gain amplifier output signal; a sequential detection logarithmic amplifier, coupled to said variable gain amplifier and responsive to said variable gain amplifier output signal to produce a detection signal corresponding to the logarithm of said variable gain amplifier output signal; and a comparator, coupled to said sequential detection logarithmic amplifier and responsive to said detection signal to provide a warning signal when said detection signal exceeds a predetermined threshold level.
Claim 2
Dependent Claim
447 words
A compact laser warning receiver for detecting a laser pulse having a laser pulse width and a laser pulse rise time, said laser warning receiver comprising: a case, to which said laser pulse and ambient light are applied, said ambient light having a variable level of intensity; a conductor assembly adapted to receive said laser pulse and said ambient light, said conductor assembly further adapted to conduct said laser pulse and said ambient light from the exterior to the interior of said case; a photoelectric transducer disposed within said case and responsive to said laser pulse received from said conductor assembly to generate a first electrical signal having an energy content and having a first signal pulse width and a first signal rise time, respectively, corresponding to said laser pulse width and said laser pulse rise time, said first signal pulse width and first signal rise time collectively providing an indication of energy content of said first electrical signal; said photoelectric transducer further responsive to said ambient light received from said conductor assembly to produce a second electrical signal having a current level corresponding to said variable ambient light; a resonant circuit, having a resonant frequency, said resonant circuit coupled inductively to said photoelectric transducer and producing an output signal having a voltage level proportional to said energy content of said first signal; an integrating circuit coupled in series with said photoelectric transducer, said integrating circuit providing a direct current path for said second electrical signal from said photoelectric transducer and further providing a high-voltage short-circuit at said resonant frequency, and producing an integrating circuit output signal having a variable voltage proportional to the integral of said variable ambient light level over a predetermined integration time interval; a high-frequency amplifier coupled to said resonant circuit and responsive to said resonant circuit output signal to produce an amplified resonant circuit output signal; a gain control amplifier coupled to said integrating circuit and responsive to said integrating circuit output signal to produce a gain control signal; a variable gain amplifier, coupled to said high-frequency amplifier and said gain control amplifier and responsive to said gain control signal to amplify said amplified resonant circuit output signal by a gain factor determined by said gain control signal, thereby producing a variable gain amplifier output signal; a sequential detection logarithmic amplifier, coupled to said variable gain amplifier and responsive to said variable gain amplifier output signal to produce a detection signal corresponding to the logarithm of said variable gain amplifier output signal; and a comparator, coupled to said sequential detection logarithmic amplifier and responsive to said detection signal to provide a warning signal when said detection signal exceeds a predetermined threshold level.
Claim 3
Dependent Claim
19 words
A laser warning receiver in accordance with claim 1, wherein said photoelectric transducer comprises at least one silicon photodiode.
Claim 4
Dependent Claim
19 words
A laser warning receiver in accordance with claim 1, wherein said photoelectric transducer comprises at least one germanium photodiode.
Claim 5
Dependent Claim
17 words
A laser warning receiver in accordance with claim 1, wherein said case has electromagnetic shielding disposed thereon.
Claim 6
Dependent Claim
17 words
A laser warning receiver in accordance with claim 1, wherein said conductor assembly comprises a lens array.
Claim 7
Dependent Claim
22 words
A laser warning receiver in accordance with claim 1, wherein said conductor assembly comprises a diffuse transmissive plate and a fiberoptic element.
Claim 8
Dependent Claim
18 words
A laser warning receiver in accordance with claim 6, wherein said fiberoptic element comprises a flexible fiberoptic bundle.
Claim 9
Dependent Claim
36 words
A laser warning receiver in accordance with claim 1, wherein said resonant frequency is selected to minimize electromagnetic interference from man-made sources and to enhance detection of laser pulses having short rise times and pulse widths.
Claim 10
Dependent Claim
54 words
A laser warning receiver in accordance with claim 1, further comprising: a built-in self-test circuit, inductively coupled to said resonant circuit, for inducing said resonant circuit to produce a simulation of said resonating output signal, said laser warning receiver being responsive to said simulation of said resonating output signal to produce a warning signal.
Claim 11
Independent Claim
241 words
A method of generating a laser warning signal in response to a laser pulse having a laser pulse width and a laser pulse rise time, comprising the steps of: (a) conducting variable levels of ambient light and said laser pulse to a photoelectric transducer; (b) generating a first electrical signal having energy content and having a first signal pulse width and a first signal rise time, respectively, corresponding to said laser pulse width and said laser pulse rise time; (c) generating a second electrical signal having a current level corresponding to said variable ambient light level; (d) producing a resonating signal having a voltage level proportional to said energy content of said first electrical signal; (e) performing an integration of said second electrical signal to produce an integration output signal having a variable voltage proportional to the integral of said variable ambient light level over a predetermined integration time interval; (f) amplifying said resonating signal to produce an amplified resonating signal; (g) amplifying said integration output signal to produce a variable gain control signal; (h) amplifying said amplified resonating signal at a gain determined by said variable gain control signal to produce a variable gain amplifier output signal; (i) applying said variable gain amplifier output signal to a sequential detection logarithmic amplifier to produce a detection signal; (j) comparing said detection signal to a predetermined reference voltage; and (k) producing a warning signal when said detection signal exceeds said reference voltage.
Claim 12
Independent Claim
241 words
A method of generating a laser warning signal in response to a laser pulse having a laser pulse width and a laser pulse rise time, comprising the steps of: (a) conducting variable levels of ambient light and said laser pulse to a photoelectric transducer; (b) generating a first electrical signal having energy content and having a first signal pulse width and a first signal rise time, respectively, corresponding to said laser pulse width and said laser pulse rise time; (c) generating a second electrical signal having a current level corresponding to said variable ambient light level; (d) producing a resonating signal having a voltage level proportional to said energy content of said first electrical signal; (e) performing an integration of said second electrical signal to produce an integration output signal having a variable voltage proportional to the integral of said variable ambient light level over a predetermined integration time interval; (f) amplifying said resonating signal to produce an amplified resonating signal; (g) amplifying said integration output signal to produce a variable gain control signal; (h) amplifying said amplified resonating signal at a gain determined by said variable gain control signal to produce a variable gain amplifier output signal; (i) applying said variable gain amplifier output signal to a sequential detection logarithmic amplifier to produce a detection signal; (j) comparing said detection signal to a predetermined reference voltage; and (k) producing a warning signal when said detection signal exceeds said reference voltage.
Claim 13
Dependent Claim
34 words
A method in accordance with claim 10, further comprising the steps of: (l) producing a simulation of said resonating signal; and (m) performing steps (e) through (k) on said simulation of said resonating signal.
Claim 14
Dependent Claim
216 words
A compact laser warning receiver responsive to a laser pulse in the presence of variable levels of ambient light to produce a warning signal, said laser warning receiver comprising: a photoelectric transducer, electrically coupled in series with a resonant tank circuit, said transducer adapted to receive said ambient light and said laser pulse, said transducer also being electrically coupled to a current averaging circuit; a gain control circuit, electrically coupled to said current averaging circuit and adapted to produce a gain control signal corresponding to said variable levels of ambient light; a variable gain amplifier, coupled to said gain control circuit to receive said gain control signal, and further coupled to a high-frequency amplifier to receive an amplified damped sinusoidal signal therefrom; said high-frequency amplifier being electrically coupled to said resonant tank circuit and adapted to receive a damped sinusoidal signal therefrom, said resonant tank circuit and said photoelectric transducer being adapted to cooperatively produce said damped sinusoidal signal in response to said laser pulse; a logarithmic amplifier, having an input electrically coupled to said variable gain amplifier to receive a variable-gain amplified damped sinusoidal signal therefrom, and having an output electrically coupled to a comparator with hysteresis; and said comparator adapted to produce said warning signal when said logarithmic amplifier output exceeds a predetermined threshold.
Claim 15
Dependent Claim
216 words
A compact laser warning receiver responsive to a laser pulse in the presence of variable levels of ambient light to produce a warning signal, said laser warning receiver comprising: a photoelectric transducer, electrically coupled in series with a resonant tank circuit, said transducer adapted to receive said ambient light and said laser pulse, said transducer also being electrically coupled to a current averaging circuit; a gain control circuit, electrically coupled to said current averaging circuit and adapted to produce a gain control signal corresponding to said variable levels of ambient light; a variable gain amplifier, coupled to said gain control circuit to receive said gain control signal, and further coupled to a high-frequency amplifier to receive an amplified damped sinusoidal signal therefrom; said high-frequency amplifier being electrically coupled to said resonant tank circuit and adapted to receive a damped sinusoidal signal therefrom, said resonant tank circuit and said photoelectric transducer being adapted to cooperatively produce said damped sinusoidal signal in response to said laser pulse; a logarithmic amplifier, having an input electrically coupled to said variable gain amplifier to receive a variable-gain amplified damped sinusoidal signal therefrom, and having an output electrically coupled to a comparator with hysteresis; and said comparator adapted to produce said warning signal when said logarithmic amplifier output exceeds a predetermined threshold.
Claim 16
Dependent Claim
60 words
A compact laser warning receiver in accordance with claim 12, further comprising: a built-in test circuit, inductively coupled to said resonant tank circuit and operative to cause said resonant tank circuit to produce a simulation of said damped sinusoidal signal; and said laser warning receiver being responsive to said simulation of said damped sinusoidal signal to produce said warning signal.
Claim 17
Dependent Claim
20 words
A compact laser warning receiver in accordance with claim 12, wherein said photoelectric transducer comprises at least one silicon photodiode.
Claim 18
Dependent Claim
20 words
A compact laser warning receiver in accordance with claim 12, wherein said photoelectric transducer comprises at least one germanium photodiode.
Claim 19
Dependent Claim
102 words
A compact laser warning receiver for detecting a laser pulse in the presence of ambient background light, said laser pulse having a pulse width and a rise time, said laser warning receiver comprising: a photoelectric transducer responsive to the laser pulse; a resonant circuit coupled to said photoelectric transducer to produce an output signal having a voltage level proportional to the energy content of said laser pulse; and a logarithmic video amplifier coupled to said resonant circuit and responsive to said output signal to produce a detection signal whose amplitude is proportional to the logarithm of the power in the laser pulse.
Claim 20
Dependent Claim
102 words
A compact laser warning receiver for detecting a laser pulse in the presence of ambient background light, said laser pulse having a pulse width and a rise time, said laser warning receiver comprising: a photoelectric transducer responsive to the laser pulse; a resonant circuit coupled to said photoelectric transducer to produce an output signal having a voltage level proportional to the energy content of said laser pulse; and a logarithmic video amplifier coupled to said resonant circuit and responsive to said output signal to produce a detection signal whose amplitude is proportional to the logarithm of the power in the laser pulse.
Claim 21
Dependent Claim
31 words
The laser warning receiver of claim 16, further comprising a comparator coupled to said logarithmic video amplifier to provide a warning signal when said detection signal exceeds a predetermined threshold level.
Claim 22
Dependent Claim
227 words
A compact laser warning receiver for detecting a laser pulse in the presence of ambient light comprising: a photoelectric transducer responsive to a laser pulse to generate a first electrical signal; said photoelectric transducer further responsive to ambient light intensity to produce a second electrical signal; a resonant circuit coupled to said photoelectric transducer to produce a resonating output signal having a voltage level proportional to an energy content of said first signal; an integrating circuit coupled to said photoelectric transducer producing an integrating circuit output signal having a voltage proportional to the integral of said second electrical signal; a high-frequency amplifier coupled to said resonant circuit and responsive to said resonant circuit output signal to produce an amplified resonant circuit output signal; a gain control amplifier coupled to said integrating circuit and responsive to said integrating circuit output signal to produce a gain control signal; a variable gain amplifier, coupled to said high-frequency amplifier and said gain control amplifier and responsive to said gain control signal to amplify said amplified resonant circuit output signal by a gain factor determined by said gain control signal, thereby producing a variable gain amplifier output signal; a logarithmic amplifier coupled to said variable gain amplifier and responsive to said variable gain amplifier output signal to produce a detection signal corresponding to the logarithm of said variable gain amplifier output signal.
Claim 23
Dependent Claim
227 words
A compact laser warning receiver for detecting a laser pulse in the presence of ambient light comprising: a photoelectric transducer responsive to a laser pulse to generate a first electrical signal; said photoelectric transducer further responsive to ambient light intensity to produce a second electrical signal; a resonant circuit coupled to said photoelectric transducer to produce a resonating output signal having a voltage level proportional to an energy content of said first signal; an integrating circuit coupled to said photoelectric transducer producing an integrating circuit output signal having a voltage proportional to the integral of said second electrical signal; a high-frequency amplifier coupled to said resonant circuit and responsive to said resonant circuit output signal to produce an amplified resonant circuit output signal; a gain control amplifier coupled to said integrating circuit and responsive to said integrating circuit output signal to produce a gain control signal; a variable gain amplifier, coupled to said high-frequency amplifier and said gain control amplifier and responsive to said gain control signal to amplify said amplified resonant circuit output signal by a gain factor determined by said gain control signal, thereby producing a variable gain amplifier output signal; a logarithmic amplifier coupled to said variable gain amplifier and responsive to said variable gain amplifier output signal to produce a detection signal corresponding to the logarithm of said variable gain amplifier output signal.
Claim 24
Dependent Claim
18 words
A laser warning receiver in accordance with claim 18, wherein said photoelectric transducer comprises at least one photodiode.
Claim 25
Dependent Claim
28 words
A laser warning receiver in accordance with claim 18, further comprising a case to which said laser pulse and ambient light are applied, said case comprising electromagnetic shielding.
Claim 26
Dependent Claim
37 words
A laser warning receiver in accordance with claim 18, further comprising a conductor assembly to receive said laser pulse and said ambient light and to transmit said laser pulse and said ambient light to said photoelectric transducer.
Claim 27
Dependent Claim
33 words
A laser warning receiver in accordance with claim 18, further comprising: a built-in self-test circuit, inductively coupled to said resonant circuit, for inducing said resonant circuit to produce a simulated resonating output signal.
Claim 28
Independent Claim
73 words
A method of generating a laser warning signal in response to a laser pulse in the presence of ambient light, wherein said laser pulse has a pulse width and a rise time, said method comprising the steps of: detecting said laser pulse; producing a resonating signal having a voltage level proportional to the energy content of said laser pulse; and applying said resonating signal to a logarithmic amplifier to produce a detection signal.
Claim 29
Independent Claim
73 words
A method of generating a laser warning signal in response to a laser pulse in the presence of ambient light, wherein said laser pulse has a pulse width and a rise time, said method comprising the steps of: detecting said laser pulse; producing a resonating signal having a voltage level proportional to the energy content of said laser pulse; and applying said resonating signal to a logarithmic amplifier to produce a detection signal.
Claim 30
Dependent Claim
29 words
The method of claim 23, further comprising: comparing said detection signal to a predetermined reference voltage; and producing a warning signal when said detection signal exceeds said reference voltage.
References Cited (Backward Citations)
US3867628A
Cited
US4015149A
Cited
US4102059A
Cited
US4236069A
Cited
US4259570A
Cited
US4276472A
Cited
US4366378A
Cited
US4724312A
Cited
US4713534A
Cited
US4748318A
Cited
US4778990A
Cited
US4851689A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |