Sensor for determining the angular position of a radiating point source in two dimensions and method of operation
First Claim
1. A sensor for determining angular position of a radiating point source in two dimensions, comprising:
- a) a point source of light located in a prescribed space;
b) a light detector adjacent said space;
c) a two-dimensional mask interposed between said detector and said space, said mask having a two-dimensional surface pattern thereon formed by a prescribed pattern of frequencies;
d) whereby light from said source travels through said mask and onto said detector, said surface pattern causing at least one of phase or frequency changes to occur, said changes being used to calculate angular position of said point source of light with respect to said detector in two dimensions.
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Accused Products
Abstract
A sensor for determining the angular position of a radiating point source in two dimensions includes a mask encoded in two skewed directions with waveforms consisting of several frequencies in prescribed patterns. The frequency spectra of the received detector patterns are computed. In order to facilitate such computations, the constituent frequencies are separated so as to be distinguished in the Fast Fourier Transform (FFT). Each of the frequency patterns that are coded on the variable transmissivity mask consists of a series of low frequencies followed by a series of variable frequencies, and a series of high frequencies. The variable frequencies exhibit frequency changes responsive to various image positions. The low and high frequencies are responsive in phase to variations in image position. The frequency variations in the variable frequencies are used to indicate coarse position while the phases of the fixed low and high frequencies are used to indicate medium and fine position. In a second embodiment, the mask pattern is formed by a first pattern including low variable and high frequency components, a second pattern with fixed low and high frequency components, and a third pattern with variable frequency components. The method of determining position is also disclosed.
87 Citations
20 Claims
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1. A sensor for determining angular position of a radiating point source in two dimensions, comprising:
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a) a point source of light located in a prescribed space;
b) a light detector adjacent said space;
c) a two-dimensional mask interposed between said detector and said space, said mask having a two-dimensional surface pattern thereon formed by a prescribed pattern of frequencies;
d) whereby light from said source travels through said mask and onto said detector, said surface pattern causing at least one of phase or frequency changes to occur, said changes being used to calculate angular position of said point source of light with respect to said detector in two dimensions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A sensor for determining angular position of a radiating point source in two dimensions, comprising:
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a) a point source of light located in a prescribed space;
b) a light detector adjacent said space;
c) a two-dimensional mask interposed between said detector and said space, said mask having a two-dimensional surface pattern thereon formed by a prescribed pattern of frequencies, said frequency pattern comprising first and second orthogonal lines, each of said lines having a series of frequencies thereon consisting of at least one low frequency, at least one variable frequency, and at least one high frequency;
d) whereby light from said source travels through said mask and onto said detector, variations of frequency in said variable frequencies being used to calculate coarse position and variations in phase in said low and high frequency being used to calculate medium and fine position. - View Dependent Claims (20)
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Specification