Optical sensor for imaging an object
First Claim
1. An optical sensor comprising:
- a structured light source for producing a pattern of contrasting areas;
a detector which comprises an array of detector elements having dimensions matched to the pattern produced by the light source;
an optical system for projecting a primary image of the light source onto an object that is to be sensed and for forming a secondary image on the detector of the primary image thus formed on the object;
adjustment means for adjusting at least part of the optical system to vary the focussing of the primary image on the object, such that when the primary image is in focus on the object, the secondary image on the detector is also in focus; and
processing means for analyzing signals produced by the detector in conjunction with information on the adjustment of the optical system;
wherein the structured light source is adjustable to interchange at least two positions of contrasting areas of the pattern produced by the light source and in that the processing means is arranged to analyze the secondary images received by the detector elements with the contrasting areas in the interchanged positions to determine those parts of the secondary images which are in focus on the detector and thereby determine the range of corresponding parts of the object which are thus in focus.
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Accused Products
Abstract
The sensor comprises a structured light source (5, 6, 7) which is adjustable so as to interchange the positions of contrasting areas of the pattern it provides, a detector (1) which comprises an array of detector elements having dimensions matched to the pattern produced by the light source, an optical system (2, 8) for projecting a primary image of the light source pattern onto an object (3) that is to be sensed and for forming a secondary image on the detector (1) of the primary image thus formed on the object (3), positioning means (4) for moving at least part (2) of the optical system so as to vary the focussing of the primary image on the object (3) and processing means (12) for analyzing signals produced by the detector (1) in conjunction with information on the adjustment of the optical system (2, 8). The optical arrangement is `confocal` so that, when the primary image is in focus on the object (3), the secondary image on the detector (1) is also in focus. The processing means (12) is arranged to analyse the images received by the detector (1) with the contrasting areas thereof in the interchanged positions to determine which parts of the images are in focus and hence determine the range of the corresponding parts of the object being viewed.
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Citations
16 Claims
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1. An optical sensor comprising:
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a structured light source for producing a pattern of contrasting areas; a detector which comprises an array of detector elements having dimensions matched to the pattern produced by the light source; an optical system for projecting a primary image of the light source onto an object that is to be sensed and for forming a secondary image on the detector of the primary image thus formed on the object; adjustment means for adjusting at least part of the optical system to vary the focussing of the primary image on the object, such that when the primary image is in focus on the object, the secondary image on the detector is also in focus; and processing means for analyzing signals produced by the detector in conjunction with information on the adjustment of the optical system; wherein the structured light source is adjustable to interchange at least two positions of contrasting areas of the pattern produced by the light source and in that the processing means is arranged to analyze the secondary images received by the detector elements with the contrasting areas in the interchanged positions to determine those parts of the secondary images which are in focus on the detector and thereby determine the range of corresponding parts of the object which are thus in focus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of determining the range of at least part of an object being viewed using an optical sensor comprising:
- a structured light source which produces a pattern of contrasting areas;
a detector which comprises an array of detector elements having dimensions matched to the pattern produced by the light source;
an optical system which projects a primary image of the light source onto an object that is to be sensed and forms a secondary image on the detector of the primary image thus formed on the object;
adjustment means which adjusts at least part of the optical system to vary the focussing of the primary image on the object such that when the primary image is in focus on the object, the secondary image on the detector is also in focus; and
processing means which analyzes signals produced by the detector in conjunction with information on the adjustment of the optical system;
said method including the steps of;(a) adjusting the structured light source to interchange the positions of contrasting areas of the pattern produced by the light source; (b) analyzing the secondary images received by the detector elements with the contrasting areas in the interchanged positions to determine those parts of the secondary images which are in focus on the detector; and (c) determining the range of corresponding parts of the object which are thus in focus.
- a structured light source which produces a pattern of contrasting areas;
Specification