US3809891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beam scanning object detection system
Assignee: Individual
•
Filing: 1972-11-21
•
Granted: 1974-05-07
•
Expires: 1992-11-21
Abstract
Abstract A detection system and method of operation for detecting the presence of an object in a predetermined zone. The detection system includes a pulsating light-emitting device, a lens apparatus for directing the pulses of light into a beam, and a scanning device for sweeping the pulsating beam of light across the detection zone. The detection system also includes at least two photocells, one of which is positioned to receive pulses of light directly from the light-emitting device and the other is positioned to receive light after being transmitted across the detection area. The signals developed by the photocells take the form of trains of electrical signals and are correlated with appropriate electronic circuitry for detecting the absence of pulses in one of the trains of signals during the presence of pulses in the other train of signals to thereby provide an indication of the presence of an object in the detection area. The electronic circuitry also digitally processes the received signals for developing an output indication representative of the size of the object, as well as the position of the object in the detection area.
Inventors
- 👤 J Erdman
- 👤 H Knappe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 22:07
CPC Classifications
G; G01; G01V; G01V8/00; G01V8/10; G01V8/20; G01V8/26
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
250 words
An apparatus for detecting the presence of an object in a detection zone and including pulsating light-emitting means for generating abrupt pulses of light, means for directing said pulses of light into a beam of pulsating light, beam scanning means positioned to receive said beam of pulsating light for sweeping the pulsating light beam across the detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone, to divide the scanned detection zone into a plurality of digital increments, first light responsive means positioned to receive without interruption the pulses of light generated by said lightemitting means for developing a first train of electrical signals in response to the receipt of said pulses of light, second light responsive means positioned to receive those pulses of light of the pulsating beam which pass uninterrupted across the detection zone for developing a second train of electrical signals in response to the receipt of those pulses of light passing uninterrupted across said zone, and circuit means coupled to both said first and said second light responsive means for developing an indicator signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to thereby provide an indication of the presence of an object in the detection zone.
Claim 2
Independent Claim
250 words
An apparatus for detecting the presence of an object in a detection zone and including pulsating light-emitting means for generating abrupt pulses of light, means for directing said pulses of light into a beam of pulsating light, beam scanning means positioned to receive said beam of pulsating light for sweeping the pulsating light beam across the detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone, to divide the scanned detection zone into a plurality of digital increments, first light responsive means positioned to receive without interruption the pulses of light generated by said lightemitting means for developing a first train of electrical signals in response to the receipt of said pulses of light, second light responsive means positioned to receive those pulses of light of the pulsating beam which pass uninterrupted across the detection zone for developing a second train of electrical signals in response to the receipt of those pulses of light passing uninterrupted across said zone, and circuit means coupled to both said first and said second light responsive means for developing an indicator signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to thereby provide an indication of the presence of an object in the detection zone.
Claim 3
Dependent Claim
43 words
An apparatus as defined in claim 1 including means for deflecting at least a portion of the light energy in said beam of pulsating light in a direction away from said scanning means and in a direction toward said first light responsive means.
Claim 4
Dependent Claim
31 words
An apparatus as defined in claim 2 wherein said deflecting means includes a partially reflective mirror disposed in a beam path extending between said light-emitting means and said beam scanning means.
Claim 5
Dependent Claim
37 words
An apparatus as defined in claim 1 including a third light responsive means positioned to receive pulses of light only when said beam scanning has completed a sweep of the pulsating light beam across the detection zone.
Claim 6
Dependent Claim
51 words
An apparatus as defined in claim 4 wherein said third light responsive means is positioned to receive pulses of light after being deflected by said beam scanning means and positioned to receive pulses of light only when said pulsating light beam has been swept to an edge of the detection zone.
Claim 7
Dependent Claim
30 words
An apparatus as defined in claim 5 wherein said pulsating light-emitting means includes a light-emitting diode and pulse generator means for periodically energizing said diode at a high repetition rate.
Claim 8
Dependent Claim
19 words
An apparatus as defined in claim 6 wherein said light-emitting diode takes the form of a gallium arsenide diode.
Claim 9
Dependent Claim
63 words
An apparatus as defined in claim 1 wherein the beam scanning means includes a parabolic mirror, rotatable reflective means substantially positioned at the focal point of said parabolic mirror for sweeping a beam of light across said parabolic mirror, and reflection means positioned beyond the focal point of said parabolic mirror and disposed to reflect the beam of pulsating light back onto itself.
Claim 10
Independent Claim
255 words
An apparatus for detecting the presence of an object in a detection zone and including pulsating radiation-emitting means for generating abrupt pulses of radiation, means for directing said pulses of radiation into a beam of pulsating radiation, scanning means positioned to receive said beam of pulsating radiation for sweeping the pulsating beam across the detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone, to divide the scanned detection zone into a plurality of digital increments, first radiation responsive means positioned to receive without interruption the pulses of radiation generated by said radiation-emitting means for developing a first train of electrical signals in response to the receipt of said pulses of light, second radiation responsive means positioned to receive those pulses of radiation of the pulsating beam which pass uninterrupted across the detection zone for developing a second train of electrical signals in response to the receipt of those pulses of radiation passing uninterrupted across said zone, and circuit means coupled to both said first and said second radiation responsive means for developing an indicator signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to thereby provide an indication of the presence of an object interrupting the passage of said radiation pulses across the detection zone.
Claim 11
Independent Claim
255 words
An apparatus for detecting the presence of an object in a detection zone and including pulsating radiation-emitting means for generating abrupt pulses of radiation, means for directing said pulses of radiation into a beam of pulsating radiation, scanning means positioned to receive said beam of pulsating radiation for sweeping the pulsating beam across the detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone, to divide the scanned detection zone into a plurality of digital increments, first radiation responsive means positioned to receive without interruption the pulses of radiation generated by said radiation-emitting means for developing a first train of electrical signals in response to the receipt of said pulses of light, second radiation responsive means positioned to receive those pulses of radiation of the pulsating beam which pass uninterrupted across the detection zone for developing a second train of electrical signals in response to the receipt of those pulses of radiation passing uninterrupted across said zone, and circuit means coupled to both said first and said second radiation responsive means for developing an indicator signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to thereby provide an indication of the presence of an object interrupting the passage of said radiation pulses across the detection zone.
Claim 12
Dependent Claim
43 words
An apparatus as defined in claim 9 including means for deflecting at least a portion of the radiation energy in said beam of pulsating radiation in a direction away from said scanning means and in a direction toward said first radiation responsive means.
Claim 13
Dependent Claim
37 words
An apparatus as defined in claim 10 including a third radiation responsive means positioned to receive pulses of radiation only when said beam scanning has completed a sweep of the pulsating radiation beam across the detection zone.
Claim 14
Independent Claim
284 words
An apparatus for producing a light curtain and including pulsating light-emitting means for generating abrupt pulses of light, lens means for directing said pulses of light into a beam of pulsating light, divider means for directing a portion of the energy in said beam of light along a first path and a portion of the energy in said beam of light along a second path, beam scanning means positioned along said first beam path for sweeping said pulsating light beam across a detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone to divide the scanned detection zone into a plurality of digital increments, first light responsive means positioned along the second path to receive uninterrupted the pulses of light generated by said light-emitting means for developing a first train of electrical signals in response to the receipt of all of said pulses of light, second light responsive means positioned to receive those pulses of light passing uninterrupted across said zone for developing a second train of electrical signals in response to the receipt of said uninterrupted pulses of light, and circuit means coupled to both said first and said second lIght responsive means for developing an output signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to indicate the presence of an object in the detection zone interrupting the passage of some of the light pulses along said first path across the detection zone.
Claim 15
Independent Claim
284 words
An apparatus for producing a light curtain and including pulsating light-emitting means for generating abrupt pulses of light, lens means for directing said pulses of light into a beam of pulsating light, divider means for directing a portion of the energy in said beam of light along a first path and a portion of the energy in said beam of light along a second path, beam scanning means positioned along said first beam path for sweeping said pulsating light beam across a detection zone once during each of at least one scanning cycle, the duration of said scanning cycle being sufficient to allow the occurrence of a plurality of pulsations of said pulsating beam during said sweeping of said beam once across said detection zone to divide the scanned detection zone into a plurality of digital increments, first light responsive means positioned along the second path to receive uninterrupted the pulses of light generated by said light-emitting means for developing a first train of electrical signals in response to the receipt of all of said pulses of light, second light responsive means positioned to receive those pulses of light passing uninterrupted across said zone for developing a second train of electrical signals in response to the receipt of said uninterrupted pulses of light, and circuit means coupled to both said first and said second lIght responsive means for developing an output signal upon the receipt of pulses in said first train of electrical signals in the absence of pulses in said second train of electrical signals to indicate the presence of an object in the detection zone interrupting the passage of some of the light pulses along said first path across the detection zone.
Claim 16
Dependent Claim
68 words
An apparatus as defined in claim 12 wherein said circuit means includes phase shifting circuit means for shifting one of said trains of electrical signals by 180*, and gating means coupled to one of said light responsive means and to said phase shifting circuit means for developing a said output upon the receipt of pulses from only said one light responsive means or said phase shifting circuit means.
Claim 17
Dependent Claim
43 words
An apparatus as defined in claim 13 including means for deflecting at least a portion of the light energy in said beam of pulsating light in a direction away from said scanning means and in a direction toward said first light responsive means.
Claim 18
Dependent Claim
31 words
An apparatus as defined in claim 14 wherein said deflecting means includes a partially reflective mirror disposed in a beam path extending between said light-emitting means and said beam scanning means.
Claim 19
Dependent Claim
37 words
An apparatus as defined in claim 13 including a third light responsive means positioned to receive pulses of light only when said beam scanning has completed a sweep of the pulsating light beam across the detection zone.
Claim 20
Dependent Claim
51 words
An apparatus as defined in claim 16 wherein said third light responsive means is positioned to receive pulses of light after being deflected by said beam scanning means and positioned to receive pulses of light only when said pulsating light beam has been swept to an edge of the detection zone.
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) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |