Position detector for maintaining a fixed distance between two objects
First Claim
1. A position detector comprising:
- first and second light emitting means for irradiating a surface of an object to be measured;
first and second light receiving means for receiving light reflected by said surface, said first and second light receiving means being positioned adjacent a corresponding one of said first and second light emitting means, in order to receive light from said corresponding light emitting means,wherein a distance from said first light receiving and emitting means to said surface as viewed in a direction substantially perpendicular to said surface is less than a distance from said second light receiving and emitting means to said surface;
calculating means for calculating a correction quantity for correcting the distances between said surface and said light receiving means, said correction quantity being calculated on the basis of a difference between the output signals of said first and second light receiving means; and
moving means for correcting the distances between said surface and said light receiving means in accordance with said correction quantity.
1 Assignment
0 Petitions
Accused Products
Abstract
A position detector includes: light emitting component for irradiating the surface of an object to be measured; two light receiving components for receiving light reflected by the measured surface, a distance from one of the light receiving components to the measured surface as viewed in a direction substantially perpendicular to the surface being different from a distance from the other of the light receiving components to the surface; calculating circuit for calculating a correction quantity for correcting the distances between the light receiving components and the surface, with the correction quantity being calculated on the basis of a difference between the output signals of the light receiving components; and, moving component for correcting the distances between the measured surface and the light receiving components in accordance with the correction quantity. A first embodiment has two light receiving components each spaced at different distances from the surface. A second embodiment has two light receiving components disposed between two light emitting components, or two light emitting components disposed between two light receiving components. A third embodiment has two light receiving components spaced at a same distance from the surface, but each spaced at different distances from a light emitting components.
20 Citations
26 Claims
-
1. A position detector comprising:
-
first and second light emitting means for irradiating a surface of an object to be measured; first and second light receiving means for receiving light reflected by said surface, said first and second light receiving means being positioned adjacent a corresponding one of said first and second light emitting means, in order to receive light from said corresponding light emitting means, wherein a distance from said first light receiving and emitting means to said surface as viewed in a direction substantially perpendicular to said surface is less than a distance from said second light receiving and emitting means to said surface; calculating means for calculating a correction quantity for correcting the distances between said surface and said light receiving means, said correction quantity being calculated on the basis of a difference between the output signals of said first and second light receiving means; and moving means for correcting the distances between said surface and said light receiving means in accordance with said correction quantity. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A position detector comprising:
-
at least one light emitting means for irradiating a surface of an object to be measured; two light receiving means for receiving light reflected by said surface, a first distance from one of said light receiving means to said light emitting means being different from a second distance from the other of said light receiving means to said light emitting means, said first and second distance lying in a direction parallel to the object surface, and a light receiving area of one of said light receiving means being different from that of the other such that said light receiving means receive different amounts of light from one another and produce different output signals therefrom; calculating means for calculating a correction quantity for correcting the distances between said surface and said light receiving means, said correction quantity being calculated by comparing the output signals of said light receiving means with one another; and moving means for correcting the distances between said surface and said light receiving means in accordance with said correction quantity. - View Dependent Claims (9)
-
-
10. A position detector comprising:
-
at least one light emitting means for irradiating a surface of an object to be measured; two light receiving means symmetrically disposed with respect to said light emitting means, each of said light receiving means including first and second detectors positioned on opposite sides of said light emitting means, a distance from one of said light receiving means to said light emitting means being different from a distance from the other of said light receiving means to said light emitting means; first calculating means for calculating a correction quantity for correcting the distances between said light receiving means and said surface, said correction quantity being calculated based on the output signals of said light receiving means; and second calculating means for calculating an angle of inclination said surface based on the output signals of said light receiving means. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A position detector comprising:
-
first and second light emitters to irradiate a surface of an object to be measured; first and second photo detectors to receive light emitted by a corresponding one of said first and second light emitters and reflected from said surface, said first and second detectors being spaced first and second distances, respectively, from said surface, said first distance being different from said second distance, said first and second detectors being positioned adjacent the corresponding emitter and being spaced said first and second distances, respectively, from said surface; and a calculation circuit to determined a correction quantity for changing a distance between the surface and said first and second detectors, said correction quantity representing a difference between output signals of said first and second detectors. - View Dependent Claims (17, 18, 19, 20)
-
-
21. A position detector comprising:
-
one light emitter to irradiate a surface of an object to be measured; first and second photo detectors to receive light reflected from said surface, said first and second detectors being spaced equal distances from said surface, with said first detector positioned closer to said light emitter than said second detector, said second detector having a larger surface area than said first detector, a calculation circuit to determine a correction quantity for changing a distance between the surface and said first and second detectors, said correction quantity representing a difference between output signals of said first and second detectors. - View Dependent Claims (22, 23, 24)
-
-
25. A position detector comprising:
-
at least one light emitter positioned to irradiate a surface of an object to be measured; first and second photo detectors positioned to receive light reflected from said surface and to generate first and second output signals therefrom, each of said first and second detectors having a characteristic output curve, of output power versus distance between a corresponding one of said detectors and said surface, wherein said output curve has an increasing slope to a peak and then a decreasing slope away from said peak as said corresponding detector moves in a direction away from said surface; said first and second detectors being positioned on a platform movable toward and away from said object and being positioned with respect to one another so that when the platform is at an optimum distance from said object, said first detector having a larger receiving area and being positioned a greater distance from said light emitter than said second detector, in order to maintain said first output signal along the increasing slope of the characteristic curve of said first photo detector, and said second output signal along the decreasing slope of the characteristic curve of said second photo detector; and a comparison circuit connected to compare said first and second output signals. - View Dependent Claims (26)
-
Specification