US3710128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for photoelectrically scanning an object by means of an optical beam
Assignee: EXATEST Messtechnik GmbH
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Filing: 1970-11-25
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Granted: 1973-01-09
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Expires: 1990-11-25
Abstract
Abstract This method is used for determining the position of width of an object, for example a wire or a metal strip. The object, which may either be glowing or else be illuminated from its backside, is scanned by an optical beam. As the beam crosses the edges of the object there is a jump in the illumination level; this is detected by a photoelectric detector. The illumination jump is not sharply defined; but it is known that the point at which the illumination level is just half of its maximum value corresponds to the instant at which the beam crosses the edge. This halfvalue point is difficult to detect in the case of the nonillumination to illumination transition, for at the time the illumination is passing through the half-value, it is not yet known what the full value is going to be. This invention palliates that disadvantage by prescanning the object by means of an auxiliary optical beam just before the scanning of the object by the main optical beam; the maximum value of the illumination as determined by this prescanning is then used as the reference. An output signal is generated by a coincidence detector at the instant when the value of the illumination of the main scanning beam just equals half the maximum value determined by the prescanning.
Inventors
- 👤 H Kubisiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:23
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/342
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
156 words
A method for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, characterized in that a prescanning is made by means of a second optical beam which precedes the scanning optical beam to generate an auxiliary signal of amplitude corresponding to full illumination, and further characterized in that the instant of the jump signal delivery is determined by coincidence of the scanning signal amplitude with a certain percentage of the held auxiliary signal amplitude, and further characterized in that the instant of the jump signal delivery is determined by coincidence of the scanning signal amplitude with the auxiliary signal amplitude which is multiplied by a coefficient 1.5 times higher than the coefficient multiplying the scanning signal amplitude.
Claim 2
Independent Claim
156 words
A method for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, characterized in that a prescanning is made by means of a second optical beam which precedes the scanning optical beam to generate an auxiliary signal of amplitude corresponding to full illumination, and further characterized in that the instant of the jump signal delivery is determined by coincidence of the scanning signal amplitude with a certain percentage of the held auxiliary signal amplitude, and further characterized in that the instant of the jump signal delivery is determined by coincidence of the scanning signal amplitude with the auxiliary signal amplitude which is multiplied by a coefficient 1.5 times higher than the coefficient multiplying the scanning signal amplitude.
Claim 3
Dependent Claim
118 words
A method as claimed in claim 1 for measuring the width of an object by means of processing the illumination jump at the edges thereof which define said width, the duration of a measuring pulse of which the edges are coincident with said illumination jumps being a measure for said width, characterized in that the pulse edge which is coincident with the illumination to non-illumination jump is generated at the instant of coincidence of the scanning signal amplituDe with half the auxiliary signal amplitude, and in that the pulse edge which is coincident with the non-illumination to illumination jump is generated at the instant of coincidence of the scanning signal amplitude with 1.5 times the auxiliary signal amplitude.
Claim 4
Dependent Claim
76 words
A method as claimed in claim 1 for measuring the width of an object by means of processing the illumination jump at the edges thereof which define said width, the duration of a measuring pulse of which the edges are coincident with said illumination jumps being a measure for said width, characterized in that said pulse edges are generated at the coincidence terminations of the scanning and auxiliary signal amplitudes both multiplied by the same coefficient.
Claim 5
Independent Claim
136 words
A device for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, said device comprising a photoelectric detector and a diaphragm system disposed in front thereof, and being characterized in that said diaphragm system comprises an auxiliary diaphragm aperture and a scanning diaphragm aperture for passing in time shifted succession one optical beam each to the detector, and further characterized in that means are provided for adjusting to equality the amplitudes of the signals successively delivered by the photoelectric detector illuminated by an optical beam passing through the auxiliary diaphragm aperture then through the scanning diaphragm aperture.
Claim 6
Independent Claim
136 words
A device for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, said device comprising a photoelectric detector and a diaphragm system disposed in front thereof, and being characterized in that said diaphragm system comprises an auxiliary diaphragm aperture and a scanning diaphragm aperture for passing in time shifted succession one optical beam each to the detector, and further characterized in that means are provided for adjusting to equality the amplitudes of the signals successively delivered by the photoelectric detector illuminated by an optical beam passing through the auxiliary diaphragm aperture then through the scanning diaphragm aperture.
Claim 7
Independent Claim
193 words
A device for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, said device comprising a photoelectric detector and a diaphragm system disposed in front thereof, and being characterized in that said diaphragm system comprises an auxiliary diaphragm aperture and a scanning diaphragm aperture for passing in time shifted succession one optical beam each to the detector, characterized in that the dimensions of the slot shaped diaphragm apertures are substantially identical, and further characterized in that the spacing of the two diaphragm apertures is chosen in such a manner that at the output of the detector the scanning and the auxiliary signal are superimposed thereby generating an amplitude step in the detector output signal corresponding to the full auxiliary signal amplitude and that the detector is coupled to circuitry means for delivering said jump signal at coincidence between said amplitude step-multiplied first constant factor-and the detector output signal amplitude-multiplied by a second constant factor.
Claim 8
Independent Claim
193 words
A device for photoelectrically scanning an object by means of an optical beam to detect the transition from non-illumination to illumination of unknown level, thereby generating a scanning signal whose amplitude is proportional to the instantaneous illumination, and to deliver a jump signal at a predetermined moment of the transition interval, said device comprising a photoelectric detector and a diaphragm system disposed in front thereof, and being characterized in that said diaphragm system comprises an auxiliary diaphragm aperture and a scanning diaphragm aperture for passing in time shifted succession one optical beam each to the detector, characterized in that the dimensions of the slot shaped diaphragm apertures are substantially identical, and further characterized in that the spacing of the two diaphragm apertures is chosen in such a manner that at the output of the detector the scanning and the auxiliary signal are superimposed thereby generating an amplitude step in the detector output signal corresponding to the full auxiliary signal amplitude and that the detector is coupled to circuitry means for delivering said jump signal at coincidence between said amplitude step-multiplied first constant factor-and the detector output signal amplitude-multiplied by a second constant factor.
Claim 9
Dependent Claim
40 words
A device as claimed in claim 5 wherein said circuitry means can produce said jump signal at the termination of coincidence between said amplitudes, and wherein said circuitry means further includes means for multiplying said amplitudes by the same coefficient.
Claim 10
Dependent Claim
63 words
A device as claimed in claim 5, wherein said circuitry means can produce said jump signal at the beginning of coincidence between said amplitudes, and wherein said circuitry means further includes means for producing a ratio of 1.5 between said first factor and said second factor, said means for producing comprising an amplifier set on the path followed by the amplitude step signal.
Claim 11
Dependent Claim
69 words
A device as claimed in claim 5 and wherein said circuitry means further includes an amplitude holding circuit for holding said amplitude step, a trigger circuit for switching on said amplitude holding circuit at a predetermined time after the beginning of said amplitude step, and an amplitude coincidence detector having to inputs which are respectively connectEd to the output of said photoelectric detector and of said amplitude holding circuit.
Claim 12
Dependent Claim
106 words
A device as claimed in claim 8, further including two coincidence detectors, wherein the inputs of the first coincidence detector are respectively connected to the output of the amplitude holding circuit and-via a 3:2 voltage divider-to the output of said photo detector, and wherein the inputs of the second coincidence detector are respectively connected to the output of the photo detector and-via a 2:1 voltage divider-to the output of said amplitude holding circuit, and wherein the outputs of both said coincidence detectors are respectively connected to control inputs of a bistable electronic switch, the signal corresponding to the width appearing at the output of the switch.
Claim 13
Independent Claim
171 words
A method of detecting an object edge at which a jump in illumination level occurs, comprising the steps of: prescanning the object with a prescanning optical beam crossing the edge of the object in a non-illumination/to illumination direction, detecting the prescanning optical beam, generating and holding an auxiliary signal having an amplitude corresponding to the maximum illumination of said prescanning optical beam, scanning the object by means of a main optical beam crossing the edge of the object in a non-illumination to illumination direction while the auxiliary signal corresponding to maximum illumination of the prescanning beam is being held, detecting the main scanning beam, generating a scanning signal having an amplitude corresponding to a portion of the full illumination of said main beam, comparing the two signals and delivering a coincidence signal when the amplitude of said scanning signal equals a predetermined percentage of the held amplitude of the auxiliary signal corresponding to maximum illumination of the prescanning beam, which coincidence signal indicates when the main scanning beam crosses said edge.
Claim 14
Independent Claim
171 words
A method of detecting an object edge at which a jump in illumination level occurs, comprising the steps of: prescanning the object with a prescanning optical beam crossing the edge of the object in a non-illumination/to illumination direction, detecting the prescanning optical beam, generating and holding an auxiliary signal having an amplitude corresponding to the maximum illumination of said prescanning optical beam, scanning the object by means of a main optical beam crossing the edge of the object in a non-illumination to illumination direction while the auxiliary signal corresponding to maximum illumination of the prescanning beam is being held, detecting the main scanning beam, generating a scanning signal having an amplitude corresponding to a portion of the full illumination of said main beam, comparing the two signals and delivering a coincidence signal when the amplitude of said scanning signal equals a predetermined percentage of the held amplitude of the auxiliary signal corresponding to maximum illumination of the prescanning beam, which coincidence signal indicates when the main scanning beam crosses said edge.
Claim 15
Dependent Claim
72 words
A method according to claim 10, wherein said main scanning beam crosses said edge while the prescanning beam is at maximum illumination, and the scanning signal corresponds to the sum of this maximum illumination of the prescanning beam and the instantaneous illumination of said main beam, and wherein the coincidence signal is delivered at the instant when said scanning signal is equal to 1.5 times the held amplitude of the auxiliary signal.
Claim 16
Independent Claim
344 words
A method of measuring the width of an object between two edges at which a jump in the illumination level occurs, comprising: prescanning the object by means of an optical beam so that this beam crosses one of the edges in the illumination to non-illumination direction and crosses the other edge in the non-illumination to illumination direction, scanning the object by means of a main optical beam so that this latter beam also crosses the said one edge in the illumination to non-illumination direction and crosses the said other edge in the non-illumination to illumination direction, providing a time shift between the prescanning and the scanning wherein for the illumination to non-illumination transition, the prescanning beam falls to its non-illumination level while the main scanning beam is still at its maximum illumination level, thereby leaving a step in the sum of the illumination levels of the prescanning and main scanning beams, which step corresponds to the maximum illumination level of the main scanning beam, and for the non-illumination to illumination transition, the main scanning beam rises to its maximum illumination level while the prescanning beam is at its maximum illumination level, thereby leaving a step in the sum of the illumination levels of the prescanning and main scanning beams, which step corresponds to the maximum illumination level of the prescanning beam; and detecting the sum of the illuminations of the prescanning and main scanning beams and generating a signal whose amplitude corresponds to said sUm, said signal then containing a step of amplitude A corresponding to the maximum illumination level of the main scanning beam and a step of amplitude B corresponding to the maximum illumination level of the prescanning beam; and comparing the amplitude of said sum signal with the step amplitudes A and B and delivering a coincidence signal at the instant when said sum signal amplitudes coincides with 0.5A and delivering another coincidence signal at the instant when said sum signal amplitude coincides with 1.5B, the time interval between these two coincidence signals then representing the width between said two edges.
Claim 17
Independent Claim
344 words
A method of measuring the width of an object between two edges at which a jump in the illumination level occurs, comprising: prescanning the object by means of an optical beam so that this beam crosses one of the edges in the illumination to non-illumination direction and crosses the other edge in the non-illumination to illumination direction, scanning the object by means of a main optical beam so that this latter beam also crosses the said one edge in the illumination to non-illumination direction and crosses the said other edge in the non-illumination to illumination direction, providing a time shift between the prescanning and the scanning wherein for the illumination to non-illumination transition, the prescanning beam falls to its non-illumination level while the main scanning beam is still at its maximum illumination level, thereby leaving a step in the sum of the illumination levels of the prescanning and main scanning beams, which step corresponds to the maximum illumination level of the main scanning beam, and for the non-illumination to illumination transition, the main scanning beam rises to its maximum illumination level while the prescanning beam is at its maximum illumination level, thereby leaving a step in the sum of the illumination levels of the prescanning and main scanning beams, which step corresponds to the maximum illumination level of the prescanning beam; and detecting the sum of the illuminations of the prescanning and main scanning beams and generating a signal whose amplitude corresponds to said sUm, said signal then containing a step of amplitude A corresponding to the maximum illumination level of the main scanning beam and a step of amplitude B corresponding to the maximum illumination level of the prescanning beam; and comparing the amplitude of said sum signal with the step amplitudes A and B and delivering a coincidence signal at the instant when said sum signal amplitudes coincides with 0.5A and delivering another coincidence signal at the instant when said sum signal amplitude coincides with 1.5B, the time interval between these two coincidence signals then representing the width between said two edges.
Claim 18
Independent Claim
136 words
A method for photoelectrically scanning an object by means of optical beams to detect the edge of the object, which edge is at the transition from non-illumination to illumination of an unknown level comprising the steps of: prescanning the edge with an auxiliary optical beam; generating an auxiliary scanning signal from said auxiliary optical beam having an amplitude corresponding to full illumination and holding the value of the signal; scanning the edge with a main optical beam; generating a main scanning signal from the main optical beam, the amplitude of the main scanning signal being proportional to the full illumination; producing a step signal on coincidence of the main scanning signal amplitude with a level equal to a predetermined percentage of the held auxiliary signal amplitude to indicate the detection of the edge of an object.
Claim 19
Independent Claim
136 words
A method for photoelectrically scanning an object by means of optical beams to detect the edge of the object, which edge is at the transition from non-illumination to illumination of an unknown level comprising the steps of: prescanning the edge with an auxiliary optical beam; generating an auxiliary scanning signal from said auxiliary optical beam having an amplitude corresponding to full illumination and holding the value of the signal; scanning the edge with a main optical beam; generating a main scanning signal from the main optical beam, the amplitude of the main scanning signal being proportional to the full illumination; producing a step signal on coincidence of the main scanning signal amplitude with a level equal to a predetermined percentage of the held auxiliary signal amplitude to indicate the detection of the edge of an object.
Claim 20
Independent Claim
87 words
A device for photoelectrically scanning an object to detect an edge of said object comprising: a photoelectric detector; means for generating a prescanning and a scanning beam; means for directing said beams to said photoelectric detector in a timed sequence; and means for receiving the electrical output of said photoelectric detector and for delivering a signal when the amplitude of said scanning beam is a predetermined percentage of the amplitude of said prescanning beam to indicate when the scanning beam has detected the edge of said object.
Claim 21
Independent Claim
87 words
A device for photoelectrically scanning an object to detect an edge of said object comprising: a photoelectric detector; means for generating a prescanning and a scanning beam; means for directing said beams to said photoelectric detector in a timed sequence; and means for receiving the electrical output of said photoelectric detector and for delivering a signal when the amplitude of said scanning beam is a predetermined percentage of the amplitude of said prescanning beam to indicate when the scanning beam has detected the edge of said object.
Claim 22
Independent Claim
111 words
A device for photoelectrically scanning an object to detect an edge of said object comprising: a light source positioned on one side of said object; a photoelectric detector located on the other side of said object; optical means for generating a prescanning beam and a scanning beam from said light source and for sequentially directing said beams to said detector; aperture means disposed in front of said detector for passing each of said beams to said detector in a timed sequence; and means coupled to said detector for receiving the output thereof and for producing a signal when the amplitude of said scanning beam is a predetermined percentage of prescanning beam.
Claim 23
Independent Claim
111 words
A device for photoelectrically scanning an object to detect an edge of said object comprising: a light source positioned on one side of said object; a photoelectric detector located on the other side of said object; optical means for generating a prescanning beam and a scanning beam from said light source and for sequentially directing said beams to said detector; aperture means disposed in front of said detector for passing each of said beams to said detector in a timed sequence; and means coupled to said detector for receiving the output thereof and for producing a signal when the amplitude of said scanning beam is a predetermined percentage of prescanning beam.
Claim 24
Dependent Claim
15 words
A device according to claim 15 wherein said aperture means includes two substantially identical apertures.
Claim 25
Dependent Claim
46 words
A device according to claim 16 wherein said optical means includes a rotating mirror positioned on said other side of said object and a focusing means located between said rotating mirror and said object for focusing the light from said light source onto said rotating mirror.
Claim 26
Independent Claim
178 words
A device for measuring the width of an object by photoelectrically scanning said object to determine the separation of the first and second edges of said object comprising: a light source positioned on one side of said object; a photoelectric detector positioned on another side of said object; means for generating a prescanning beam and a scanning beam corresponding to each edge of said object; a diaphragm aperture means positioned in front of said photoelectric detector for directing said beams in a timed sequence to said photoelectric detector; means coupled to said photoelectric detector for producing a first signal when the amplitude of said scanning beam crossing the first edge corresponds to a predetermined percentage of the amplitude of the prescanning beam crossing said first edge and a second signal when the amplitude of said scanning beam crossing the second edge corresponds to a predetermined percentage of the amplitude of the prescanning beam crossing said second edge; and means for timing the duration between said first signal and said second signal for detecting the width of said object.
Claim 27
Independent Claim
178 words
A device for measuring the width of an object by photoelectrically scanning said object to determine the separation of the first and second edges of said object comprising: a light source positioned on one side of said object; a photoelectric detector positioned on another side of said object; means for generating a prescanning beam and a scanning beam corresponding to each edge of said object; a diaphragm aperture means positioned in front of said photoelectric detector for directing said beams in a timed sequence to said photoelectric detector; means coupled to said photoelectric detector for producing a first signal when the amplitude of said scanning beam crossing the first edge corresponds to a predetermined percentage of the amplitude of the prescanning beam crossing said first edge and a second signal when the amplitude of said scanning beam crossing the second edge corresponds to a predetermined percentage of the amplitude of the prescanning beam crossing said second edge; and means for timing the duration between said first signal and said second signal for detecting the width of said object.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |