US4063085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for electronic scanning
Assignee: COMETA SA
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Filing: 1975-11-03
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Granted: 1977-12-13
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Expires: 1995-11-03
Abstract
Abstract The present invention relates to a method of and apparatus for electronic scanning of the kind in which an optical beam emitted and reflected on itself on a catadioptric mirror is displaced rapidly in space so as to sweep over a zone under control, the optical beam being formed by an electro-luminescent diode which projects a continuous train of optical impulses towards the catadioptric mirror, and said reflected impulses are received on a phototransistor device, the train of electrical impulses intended to excite an electro-luminescent diode and formed by a single preparation means being switched electronically in a cyclic manner, while at the same time the photo-transistor associated with the electro-luminescent diode in course of emission is rendered operative, the train of impulses being switched over from one diode to the next following at each impulse, characterized in that in order to ensure the state-by-state progression of the electronic switching circuit, each state validated by this circuit is compared with counting signals obtained independently of this circuit, and the continuation of the sequence is only permitted in the event of agreement, any disagreement due to a missed state or the stoppage of the selector causing the interruption of the sequence and the tripping of an alarm.
Inventors
- 👤 Michel Henri Montanvert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:05
CPC Classifications
G; G01; G01V; G01V8/00; G01V8/10; G01V8/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
314 words
A method of controlling a scanning luminous barrier system comprising providing a series of electro-luminescent diodes, and associating a series of phototransistors respectively with said electro-luminescent diodes, triggering said diodes in sequence to emit a light pulse, and simultaneously triggering the associated phototransistors in sequence to enable the phototransistors to sense a light pulse, reflecting the light pulse from each diode to its associated phototransistor for detection, simultaneously pulsing a multi state switching circuit and a multi state comparison circuit, triggering said diodes and phototransistors in response to the state of said switching circuit, providing a first control step, said first control step including comparing the state of the switching circuit with the state of the comparison circuit to determine agreement between the states of these circuits and continuing triggering of the electro-luminescent diodes and phototransistors only upon a condition of agreement of the states of the switching circuit and comparison circuit, providing a second control step, said second control step including monitoring signals indicating reception of light pulses by the phototransistors and stopping the scanning if the signal monitored indicates reception of light pulses by the phototransistors during a time period in which said diodes are not to be triggered, providing a third control step, said third control step including changing the state of said switching circuit during a time period in which said diodes are not to be triggered while maintaining the state of the comparison circuit and continuing the scanning only if there is disagreement between the levels of the comparison circuit and the switching circuit, and providing a fourth control step, said fourth control step including monitoring the level of the light pulses sensed at the phototransistors, providing an indication of signal from the phototransistors only if the level monitored is within a predetermined range of levels, and stopping sequencing in the absence of indication of signal from the phototransistors.
Claim 2
Independent Claim
314 words
A method of controlling a scanning luminous barrier system comprising providing a series of electro-luminescent diodes, and associating a series of phototransistors respectively with said electro-luminescent diodes, triggering said diodes in sequence to emit a light pulse, and simultaneously triggering the associated phototransistors in sequence to enable the phototransistors to sense a light pulse, reflecting the light pulse from each diode to its associated phototransistor for detection, simultaneously pulsing a multi state switching circuit and a multi state comparison circuit, triggering said diodes and phototransistors in response to the state of said switching circuit, providing a first control step, said first control step including comparing the state of the switching circuit with the state of the comparison circuit to determine agreement between the states of these circuits and continuing triggering of the electro-luminescent diodes and phototransistors only upon a condition of agreement of the states of the switching circuit and comparison circuit, providing a second control step, said second control step including monitoring signals indicating reception of light pulses by the phototransistors and stopping the scanning if the signal monitored indicates reception of light pulses by the phototransistors during a time period in which said diodes are not to be triggered, providing a third control step, said third control step including changing the state of said switching circuit during a time period in which said diodes are not to be triggered while maintaining the state of the comparison circuit and continuing the scanning only if there is disagreement between the levels of the comparison circuit and the switching circuit, and providing a fourth control step, said fourth control step including monitoring the level of the light pulses sensed at the phototransistors, providing an indication of signal from the phototransistors only if the level monitored is within a predetermined range of levels, and stopping sequencing in the absence of indication of signal from the phototransistors.
Claim 3
Dependent Claim
52 words
The process of claim 1 wherein said second control step further includes providing a first supplementary state, in addition to the number of states required for triggering said diodes, after the sequence of triggering said diodes and wherein said monitoring of the signals occur at the time of said first supplementary state.
Claim 4
Dependent Claim
46 words
The process according to claim 1 in which said changing the state during said third control step includes sending an impulse to the switching circuit to cause the switching circuit to skip a state while preventing the impulse from changing the state of the comparison circuit.
Claim 5
Dependent Claim
36 words
The process according to claim 1 wherein said predetermined range of levels is between an upper threshold level slightly above the normal phototransistor output level and a lower threshold level slightly below the normal phototransistor level.
Claim 6
Dependent Claim
196 words
A scanning luminous barrier system comprising a plurality of electro-luminescent diodes for producing light outputs, a plurality of phototransistors, one associated with each of said diodes for producing an output in response to a light input, reflecting means for reflecting light from each of the diodes onto its associated phototransistor, control means for producing control pulses, switching means comprising n output means, wherein n is the number of diodes, responsive to the control pulses for state-by-state triggering in sequence of each diode and its corresponding phototransistor so that a scanning effect is produced, and further comprising a first and a second supplementary output means for providing first and second additional states respectively at the end of each state-by-state triggering sequence during the time when no diode is to be triggered, auxiliary counting means operated in parallel with the switching means for counting control pulses, comparison means connected to the output means for comparing the state of the auxiliary counting means with the state of the switching means, and means for terminating the state-by-state triggering upon a discrepancy between the state of the auxiliary counting means and the state of the switching means during the triggering sequence.
Claim 7
Dependent Claim
196 words
A scanning luminous barrier system comprising a plurality of electro-luminescent diodes for producing light outputs, a plurality of phototransistors, one associated with each of said diodes for producing an output in response to a light input, reflecting means for reflecting light from each of the diodes onto its associated phototransistor, control means for producing control pulses, switching means comprising n output means, wherein n is the number of diodes, responsive to the control pulses for state-by-state triggering in sequence of each diode and its corresponding phototransistor so that a scanning effect is produced, and further comprising a first and a second supplementary output means for providing first and second additional states respectively at the end of each state-by-state triggering sequence during the time when no diode is to be triggered, auxiliary counting means operated in parallel with the switching means for counting control pulses, comparison means connected to the output means for comparing the state of the auxiliary counting means with the state of the switching means, and means for terminating the state-by-state triggering upon a discrepancy between the state of the auxiliary counting means and the state of the switching means during the triggering sequence.
Claim 8
Dependent Claim
62 words
The system of claim 5 further comprising a control circuit for resetting the switching means to begin a new state-by-state triggering sequence and connected to the first supplementary output, phototransistor signal responsive means operably connected to the control circuit means for preventing resetting of said switching means in the event of a phototransistor output at the time of said first additional state.
Claim 9
Dependent Claim
77 words
Device of claim 5 further comprising signal injecting means for energizing the second supplementary output of the switching means without increasing the count of the auxiliary counter to simulate a skipped state, and control circuit means connected to the comparison means for preventing further state-by-state triggering cycles if the comparison means fails to determine a discrepancy between the state of the auxiliary counting means and the state of the switching means during simulation of the skipped state.
Claim 10
Dependent Claim
27 words
The system of claim 6 further comprising phototransistor responsive means comprising a threshold detector having an upper threshold only slightly above the normal output of the phototransistors.
References Cited (Backward Citations)
US3678492A
Cited
US3704396A
Cited
US3723737A
Cited
US3781842A
Cited
US3798551A
Cited
US3789384A
Cited
US3805061A
Cited
US3825745A
Cited
US3970846A
Cited
US3928849A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |