EP0071667A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Device for determining the real or the virtual distance of a source of light from a measuring plane
Assignee: Morander Karl-Erik
•
Filing: 1981-08-11
•
Granted: —
•
Expires: 2001-08-11
Abstract
Abstract The invention relates to a device for determining the real or the virtual distance of a source of light (3) from a measuring plane (20). Such devices are preferably em- pioyed in position detectors in which light impinges on the surface of the object to be measured, said light being reflected from said surface towards a photodetector. The light emitted by the light source is imaged at different points on said detector, this depending on the position of the surface of the object to be measured. According to the invention, the imaging system (71,72,73) and the position-sensitive detector form a rotationally symmetrical arrangement. This renders the function of the device independent of any lateral displacement of the light source, of different degrees of reflexion of scattering produced by the surface of the object to be investigated, and of the shape of the surface of the object to be investigated.
Inventors
- 👤 Karl-Erik Morander
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 14:05
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/026; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/46
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
72 words
A device for determining the real or the virtual distance of a source of light (3) from a measuring plane (20) comprising an optical imaging system (7; 71, 72, 73; 75) adapted to image, onto a photosensitive detector (8), light (4) emitted by the source of light, characterized in that said optical imaging system and said photosensitive detector are constructed in a rotationally symmetrical manner in relation to a common axis (21).
Claim 2
Independent Claim
72 words
A device for determining the real or the virtual distance of a source of light (3) from a measuring plane (20) comprising an optical imaging system (7; 71, 72, 73; 75) adapted to image, onto a photosensitive detector (8), light (4) emitted by the source of light, characterized in that said optical imaging system and said photosensitive detector are constructed in a rotationally symmetrical manner in relation to a common axis (21).
Claim 3
Dependent Claim
34 words
The device of claim 1, characterized in that said optical imaging system comprises a slit diaphragm (75) having a narrow circular slit with the centre of the circle being located on said axis (21).
Claim 4
Dependent Claim
31 words
A device as claimed in claim 1 or claim 2, characterized in that said optical imaging system comprises a rotationally symmetrical arrangement including a plurality of separate lenses (71, 72, 73).
Claim 5
Dependent Claim
22 words
A device as claimed in claim 1 or claim 2, characterized in that said optical imaging system comprises a torus-shaped lens (7).
Claim 6
Independent Claim
23 words
The device as claimed in any of the preceding claims 1 to 4, characterized in that said photosensitive detector is a position-sensitive detector.
Claim 7
Independent Claim
41 words
A device as claimed in any of the preceding claims 1 to 5, characterized in that said position-sensitive photodetector comprises an inner electrode (11) and an outer electrode (12), said electrodes having the form of circular annuli and being disposed concentrically.
Claim 8
Independent Claim
43 words
A device as claimed in any of the preceding claims 1 to 5, characterized in that said position -sensitive photodetector comprises a plurality of discrete segments, said segments being respectively positioned on an inner circle and an outer circle, said circles being concentric.
Claim 9
Independent Claim
33 words
A device as claimed in any of the preceding claims 1 to 7, characterized in that said position-sensitive photodetector is provided with an aperture (10) adapted to pass said beam of light (4).
Claim 10
Dependent Claim
50 words
A device as claimed in claim 6 or claim 7 characterized in that said position-sensitive photodetector (9) is provided with an aperture (10) adapted to pass the light beam, said aperture being disposed within said inner electrode (11) or within said circle on which said inner electrode segments are arranged.
Claim 11
Independent Claim
28 words
A device as claimed in any of the preceding claims 1 to 9, characterized in that said source of light (3) is connected to a stabilizing circuit (13).
Claim 12
Independent Claim
32 words
A device as claimed in any of the preceding claims 1 to 10, characterized by a signal processing circuit (14) connected to said position-sensitive photodetector (8) and adapted to compensate for non-linearities.
Claim 13
Independent Claim
68 words
A device as claimed in any of the preceding claims 1 to 10, characterized in that the electrodes (1, 2, 11, 12) or the electrode segments (100, 101), respectively, of a position-sensitive photodetector (8) are connected to the inputs of an adder (15) and a subtractor (16), respectively, and that the output signals of said adder and said subtractor are fed to the inputs of a divider (17).
Claim 14
Dependent Claim
33 words
The device of claim 11, characterized in that amplifiers and/or impedance converters (18) are connected between the electrodes (1, 2, 11, 12) or the electrode segments (100, 101), respectively, of a position-sensitive photodetector.
Claim 15
Independent Claim
84 words
A device for determining the position of an object in which a light beam (4) produced by a light source (3) is directed onto the surface (5) of said object, and in which the light (6) reflected or backscattered from this surface (5) is imaged by means of a lens (7) on a position-sensitive photodetector (8), characterized in that a plurality of position-sensitive photodetectors and a plurality of lenses associated therewith form a rotationally symmetrical array in relation to the incident beam of light.
Claim 16
Independent Claim
84 words
A device for determining the position of an object in which a light beam (4) produced by a light source (3) is directed onto the surface (5) of said object, and in which the light (6) reflected or backscattered from this surface (5) is imaged by means of a lens (7) on a position-sensitive photodetector (8), characterized in that a plurality of position-sensitive photodetectors and a plurality of lenses associated therewith form a rotationally symmetrical array in relation to the incident beam of light.
Claim 17
Dependent Claim
40 words
The device of claim 14, characterized in that the angle α between the axis of the light beam (4) and the light ray passing through the point of impingement (51) and the centre of the lens is smaller than 30°.
Claim 18
Independent Claim
45 words
A device as claimed in any of the preceding claims 1 to 15, characterized in that the intensity of the source of light (3) is adapted to be modulated and that a filter tuned to the modulation frequency is disposed downstream of the position-sensitive photodetectors.
References Cited (Backward Citations)
GB1277319A
Cited
DE2424073A1
Cited
GB1475232A
Cited
DE2617797A1
Cited
DE2845850A1
Cited
GB2066449A
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.