US4266875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for contact-free interval or thickness measurement by control of the direction of a light ray beam
Assignee: Siemens AG
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Filing: 1980-02-05
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Granted: 1981-05-12
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Expires: 2000-02-05
Abstract
Abstract A method and apparatus is disclosed for contact-free interval or thickness measurement. A sharply concentrated light beam is periodically deflected over a measuring space having a measuring plane and reference plane situated therein. A beam divider is positioned after the beam deflector and deflects the beam towards first, second and third light detectors. A fourth light detector is also provided to receive reflected light from the measuring plane and reference plane. A first time difference is utilized to control deflection frequency of the light beam; a second time difference controls deflection amplitude of the light beam; a third time difference determines a spacing of the measuring plane from the reference plane; and a fourth time difference corrects for changes in a direction of the light beam such as when a new light source is positioned in the system or when other directional errors occur.
Inventors
- 👤 Viktor Bodlaj
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:27
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/46; G01S17/48; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0608
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
237 words
A method for contact-free interval or thickness measurement, comprising the steps of: providing a sharply concentrated light ray beam generated by a light source and periodically deflecting it over a measured space by means of a beam deflector; a measuring plane being positioned in the measuring space and spaced from a reference plane by the interval or thickness to be measured; providing first, third and fourth light beam detectors positioned to receive reflections of the light beam from a beam divider and a second light beam detector positioned to receive reflections from the measuring and reference planes; measuring the interval or thickness by use of a time difference between a standard signal from the first detector and at least one spacing measuring signal from the second detector; controlling deflection frequency of the light beam by use of a time difference between a reference signal derived from a generator controlling deflection frequency and said standard signal; controlling deflection amplitude of the light beam by use of a time difference between said standard signal and a first measuring signal derived from the third light detector; and controlling a direction of the light ray beam by use of a time difference between one of said standard and first measuring signals and a second measuring signal derived from the fourth light detector, the direction of the light ray beam being corrected when this time difference deviates from a given reference value.
Claim 2
Independent Claim
237 words
A method for contact-free interval or thickness measurement, comprising the steps of: providing a sharply concentrated light ray beam generated by a light source and periodically deflecting it over a measured space by means of a beam deflector; a measuring plane being positioned in the measuring space and spaced from a reference plane by the interval or thickness to be measured; providing first, third and fourth light beam detectors positioned to receive reflections of the light beam from a beam divider and a second light beam detector positioned to receive reflections from the measuring and reference planes; measuring the interval or thickness by use of a time difference between a standard signal from the first detector and at least one spacing measuring signal from the second detector; controlling deflection frequency of the light beam by use of a time difference between a reference signal derived from a generator controlling deflection frequency and said standard signal; controlling deflection amplitude of the light beam by use of a time difference between said standard signal and a first measuring signal derived from the third light detector; and controlling a direction of the light ray beam by use of a time difference between one of said standard and first measuring signals and a second measuring signal derived from the fourth light detector, the direction of the light ray beam being corrected when this time difference deviates from a given reference value.
Claim 3
Dependent Claim
42 words
The method of claim 1 including the steps of utilizing the time difference for control of the light beam direction to control a variable voltage source which superimposes a correction voltage upon a periodic deflection voltage resulting from the deflection frequency generator.
Claim 4
Independent Claim
242 words
A device for contact-free interval or thickness measurement, comprising: light source means for generating a light beam; beam deflecting means for periodically deflecting the beam over a measuring space having a measuring plane therein spaced from a reference plane; a beam divider following the beam deflector; first, second, and third light detectors positioned to receive a beam divided out from the beam divider and a fourth light detector positioned to receive light reflected from the measuring plane and reference plane; spacing measurement means for determining a spacing between the measuring plane and reference plane by creating of a time difference between a standard signal from the first detector and a spacing measuring signal from the fourth detector; deflection frequency control means connected for control of beam deflection frequency to the beam deflecting means by creating a time difference between a reference signal derived from a generator controlling periodic deflection and said standard signal; means for controlling deflection amplitude of the light beam connected to means for establishing beam deflector amplitude by creating a time difference between said standard signal and a first measuring signal derived from the second light detector; and means for directional control of the light ray beam connected to the beam deflecting means for establishing beam direction and controlling the direction by creating a time difference through a comparison of one of said standard and first measuring signals and a second measuring signal derived from the third light detector.
Claim 5
Independent Claim
242 words
A device for contact-free interval or thickness measurement, comprising: light source means for generating a light beam; beam deflecting means for periodically deflecting the beam over a measuring space having a measuring plane therein spaced from a reference plane; a beam divider following the beam deflector; first, second, and third light detectors positioned to receive a beam divided out from the beam divider and a fourth light detector positioned to receive light reflected from the measuring plane and reference plane; spacing measurement means for determining a spacing between the measuring plane and reference plane by creating of a time difference between a standard signal from the first detector and a spacing measuring signal from the fourth detector; deflection frequency control means connected for control of beam deflection frequency to the beam deflecting means by creating a time difference between a reference signal derived from a generator controlling periodic deflection and said standard signal; means for controlling deflection amplitude of the light beam connected to means for establishing beam deflector amplitude by creating a time difference between said standard signal and a first measuring signal derived from the second light detector; and means for directional control of the light ray beam connected to the beam deflecting means for establishing beam direction and controlling the direction by creating a time difference through a comparison of one of said standard and first measuring signals and a second measuring signal derived from the third light detector.
Claim 6
Dependent Claim
86 words
The device of claim 3 wherein the means for directional control of the light beam comprises a time discriminator connected to the second measuring signal and one of the standard and first measuring signals, an output pulse of the time discriminator connecting to a pulse/digital converter and thereafter to a digital/analogue converter which has a DC voltage output supplied to a differential amplifier also connected to a fixed reference voltage, and an output of the differential amplifier providing a control signal for the beam deflecting means.
Claim 7
Dependent Claim
20 words
A device according to claim 4 wherein the output of the differential amplifier directly connects to a piezo-ceramic beam deflector.
Claim 8
Dependent Claim
35 words
A device according to claim 4 wherein an output voltage of the differential amplifier is supplied to a motor potentiometer whose moving center tab controlled by the motor is connected to the beam deflecting means.
References Cited (Backward Citations)
US3923395A
Cited
US4053227A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |