Abstract: An optical distance measuring apparatus includes: a scanning element scanning a coherent irradiation light from a light source and sending it to an object under measurement; a photo detector receiving the irradiation light modulated by being passed through the object under measurement in accordance with the scanning, and performing photoelectric conversion on the irradiation light; and a measuring unit obtaining phase information of the object under measurement based on a signal photoelectrically converted by the photo detector and a signal to be a reference for the scanning by the scanning element, and obtaining a measurement value regarding the object under measurement based on the phase information.

Abstract: An optical distance measuring apparatus includes: a scanning element scanning a coherent irradiation light from a light source and sending it to an object under measurement; a photo detector receiving the irradiation light modulated by being passed through the object under measurement in accordance with the scanning, and performing photoelectric conversion on the irradiation light; and a measuring unit obtaining phase information of the object under measurement based on a signal photoelectrically converted by the photo detector and a signal to be a reference for the scanning by the scanning element, and obtaining a measurement value regarding the object under measurement based on the phase information.

Abstract: A spatial frequency reproducing apparatus includes a light source, a first means for modulating a light emitted from the light source into two lights having different frequencies and separately irradiated adjacently, a second means for two-dimensionally scanning the two lights, a third means for irradiating an object under measurement with the two lights, a fourth means for receiving and converting into an electrical signal at least two or more divided lights from the object under measurement with a boundary line being interposed therebetween in a direction substantially perpendicular to the direction separating the two lights, a fifth means for amplifying respective photoelectrically converted electrical signals while varying a degree of amplification according to frequencies thereof and generating a difference signal or a summation signal of the amplified signals, and a sixth means for obtaining a phase difference or an intensity difference of these signals to obtain a measurement value.

Abstract: A distance measurement system includes: an irradiating means for irradiating two coherent electromagnetic waves having frequencies different from each other to an object under measurement in a partially displacing manner while having a same area; an electromagnetic wave detecting means for detecting electromagnetic waves from at least two or more areas on the object under measurement with a boundary line being interposed therebetween to extend in a direction substantially perpendicular to the displacement direction; a signal generating means for generating a difference signal or a summation signal of respective outputs of the electromagnetic waves detected in the electromagnetic wave detecting means at symmetrical positions with respect to the boundary line; and a measuring means for obtaining a phase difference or intensity difference of the difference signal or summation signal to obtain measurement values.

Abstract: A spatial frequency reproducing apparatus includes a light source, a first means for modulating a light emitted from the light source into two lights having different frequencies and separately irradiated adjacently, a second means for two-dimensionally scanning the two lights, a third means for irradiating an object under measurement with the two lights, a fourth means for receiving and converting into an electrical signal at least two or more divided lights from the object under measurement with a boundary line being interposed therebetween in a direction substantially perpendicular to the direction separating the two lights, a fifth means for amplifying respective photoelectrically converted electrical signals while varying a degree of amplification according to frequencies thereof and generating a difference signal or a summation signal of the amplified signals, and a sixth means for obtaining a phase difference or an intensity difference of these signals to obtain a measurement value.

Abstract: A distance measurement system includes: an irradiating means for irradiating two coherent electromagnetic waves having frequencies different from each other to an object under measurement in a partially displacing manner while having a same area; an electromagnetic wave detecting means for detecting electromagnetic waves from at least two or more areas on the object under measurement with a boundary line being interposed therebetween to extend in a direction substantially perpendicular to the displacement direction; a signal generating means for generating a difference signal or a summation signal of respective outputs of the electromagnetic waves detected in the electromagnetic wave detecting means at symmetrical positions with respect to the boundary line; and a measuring means for obtaining a phase difference or intensity difference of the difference signal or summation signal to obtain measurement values.

Abstract: A 3-D shape measurement apparatus for grasping the state of an object with ease and accuracy is provided.

Abstract: A condition analysis apparatus capable of grasping the condition of an object easily and accurately is provided. The condition analysis apparatus 1 includes a three-dimensional sensor 10 for measuring sampling-point-moves in the height direction of an object 2 existing in a target area at a plurality of sampling points, and area definition means 22 for defining an area where a plurality of the sampling-point-moves are in the generally same phase. The thus constructed condition analysis apparatus 1 can grasp the condition of the object 2 easily and accurately. Preferably, the condition analysis apparatus 1 includes information output means 40 for outputting information of an area including the area defined by the area definition means 22.

Abstract: To provide a monitoring device which can detect conditions of a sleeping person reliably and which is simple. A monitoring device comprising: multiple independent distance sensors 11 installed facing different positions in a monitored target area 50 to be monitored for measuring a distance to a monitored target 2, a calculating unit 22 for calculating changes over time in the outputs of the distance sensors 11, and a detection processor 23 for detecting changes in shape of the monitored target 2 based on the calculated changes over time in one or multiple distance sensor 11 among the multiple distance sensors 11.

Abstract: A condition analysis apparatus capable of grasping the condition of an object easily and accurately is provided. The condition analysis apparatus 1 includes a three-dimensional sensor 10 for measuring sampling-point-moves in the height direction of an object 2 existing in a target area at a plurality of sampling points, and area definition means 22 for defining an area where a plurality of the sampling-point-moves are in the generally same phase. The thus constructed condition analysis apparatus 1 can grasp the condition of the object 2 easily and accurately. Preferably, the condition analysis apparatus 1 includes information output means 40 for outputting information of an area including the area defined by the area definition means 22.

Abstract: A 3-D shape measurement apparatus for grasping the state of an object with ease and accuracy is provided.

Abstract: To provide a monitoring device which can detect conditions of a sleeping person reliably and which is simple. A monitoring device comprising: multiple independent distance sensors 11 installed facing different positions in a monitored target area 50 to be monitored for measuring a distance to a monitored target 2, a calculating unit 22 for calculating changes over time in the outputs of the distance sensors 11, and a detection processor 23 for detecting changes in shape of the monitored target 2 based on the calculated changes over time in one or multiple distance sensor 11 among the multiple distance sensors 11.

Abstract: The present invention is directed to a method for recognizing and classifying one or more unknown patterns, such as letters or numerals, by comparing these unknown patterns to a set of reference patterns. The unknown patterns, as well as the reference patterns, are irradiated by a coherent or incoherent beam, and correlation outputs are measured which would be at peak value of an auto-correlation output or a cross-correlation output between the unknown patterns and the reference patterns. Membership functions are created for each of the reference patterns, and a membership value is estimated or calculated on the basis of the output correlation between the unknown patterns and the reference patterns. Based upon this membership value, the specific unknown pattern is determined.

Abstract: An object of the invention is to provide a method and a apparatus for optical pattern recognition capable of accurately comparing and identifying a reference image accurately at a real-time even when the input image rotates or its size changes by being compared with a reference image that is a desirous target. The method and apparatus comprise the processes of; steps (6, 11) for independently obtaining a lower-frequency component and a higher-frequency component from a joint Fourier transform image 5 of the reference image 4 and the input image 3; steps (10, 15) for calculating correlation coefficients respectively from the lower-frequency component and the higher-frequency component; step (16) for obtaining a ratio of the respective correlation coefficients; and step (19) for identifying and comparing a correlation coefficient ratio of the two same reference images to be required with a correlation coefficient ratio obtained from step (16).

Abstract: A method and apparatus for identifying an object having non-specific outer boundaries, such as a leukocyte, includes a device for tracking, in two dimensions, the position of the object to be identified. An identification device for identifying the object tracked by the device includes a coherent light beam emissions source, a lens assembly to direct the coherent light beam from the source to the object to be identified, a detection device for detecting the light beam which is transmitted through the object, the detection device provided with a plurality of circular or semicircular coaxial sections, the center of which is at the axis of the coherent light beam in the plane on which Fraunhofer's diffraction patterns are formed. Finally, an identification apparatus is provided which uses the output of the detection device to provide various characteristic parameters which are utilized to identify the object.

Abstract: A method of obtaining a correlation between a pattern to be identified and a number of reference patterns by irradiating and displaying the pattern to be identified and the reference patterns on an optical display plane, thereby producing a complex optical amplitude distribution. This distribution is Fourier-transformed to produce a first power spectrum corresponding to the light intensity distribution of its Fourier transformation patterns. The patterns are again irradiated based upon the first power spectrum and a second Fourier transform is performed to produce a second power spectrum which is the light intensity distribution of the second Fourier transformation pattern. The area of this distribution is restricted by controlling the transmittance or the reflectance of each of the portions of the display plane.

Abstract: An optical associative identifier is disclosed which is used to determine the closest match between an image to be identified and a plurality of reference images. The identifier includes a display area for displaying the various images, the display area additionally functioning as a spatial light modulator. First and second optical Fourier transform devices are included which are used to compare the reference images to the image to be identified. The output light intensity of each of the reference images is modulated in accordance with a two-dimensional intensity distribution corresponding to the correlation between the image to be identified in each of the reference images. Based upon a comparison of these output light intensities, a match between the image to be identified and one of the reference images can be made.

Abstract: An optical correlator according to the present invention generates a cross-correlation peak of two patterns of pictorial information to be compared. It generates pictorial patterns of a sum of the two patterns of pictorial information and of a difference between the two patterns of pictorial information by a phase conjugate waveform, transforms the pictorial patterns into first Fourier transform images, generates a pictorial pattern of a difference between an intensity distribution of the first Fourier transform images by the phase conjugate waveform, and transforms the pictorial pattern of a difference between an intensity distribution of the first Fourier transform images into second Fourier transform images. The optical correlator detects a cross-correlation peak of the two patterns of pictorial information for comparison at a high S/N ratio.

Abstract: An optical filter-coupler comprises at least two optical waveguides such as optical fibers closely spaced apart to each other for allowing light propagating in one waveguide to couple into the other. Materials for the waveguides are selected to have different wavelength-dispersive refractive indexes so that the waveguides have a common refractive index at a selected wavelength, whereby a complete power transfer is obtained at such selected wavelength.

Abstract: An optical waveguide coupler comprises at least two optical waveguides such as optical fibers closely spaced apart for allowing light propagating in one optical waveguide to couple into the other. Optical waveguide portions of the waveguides are made of materials having different refractive indices respectively. The feature stabilizes the splitting ratio against a slight change in coupling length, whereby the control of the coupling ratio during manufacture becomes easy, and deviations in splitting ratio can be greatly reduced.