Abstract: An apparatus for determining an occupant's posture is provided which includes a sensor having at least one pair of linear photosensor arrays each comprising a plurality of photosensor elements, for forming an image of an occupant, a distance measurement processor that derives distance distributions in fields of view monitored by the linear photosensor arrays, from the image of the occupant formed by the sensor, and an occupant discrimination processor that compares patterns of the distance distributions with model patterns of distance distributions preliminarily stored in the processor, so as to determine the presence and posture of the occupant.

Abstract: The present invention detects not only the presence of an occupant, but also his/her posture based on the distance distribution of each portion of the occupant within each of monitor fields of view, which distance distribution is obtained by means of a single-stage or multistage occupant sensor. The result of the detection can be used in controlling inflation of an air bag, so as to avoid an accident that might otherwise occur upon inflation of the air bag, thus assuring increased safety and reliability. Since the acceleration can be calculated by arithmetic processing of the output of the distance sensor, there is no particular need to provide an exclusive acceleration sensor. Further, an optical system including the distance sensor may be designed so that the sensor can also detect an occupant whose part of the body is thrust out of automobile.

Abstract: A bidirectional optically powered signal transmission apparatus includes a control station and a field station which are optically linked by an optical fiber for signal transmission and for power transmission. The control station sends a first light beam to a light receiver in the field station. The field station sends a second light beam to the control station. The first and second light beams are at different wavelengths so that simultaneous bidirectional transmission is enabled. The field station further converts a portion of the first light beam to electric power for powering the field station. The field station demodulates an AC component superimposed on the light it receives to produce an AC electric signal for control of the field station. The control and field stations include respective optical transceiver circuits, each including a light source, light receiver and light splitter-coupler.

Abstract: A bidirectional optically powered signal transmission apparatus includes a control station and a field station which are optically linked by an optical fiber. The control station sends a first light beam to a light receiver in the field station. The field station sends a second light beam to the control station. The first and second light beams are at different wavelengths so that simultaneous bidirectional transmission is enabled. The field station further converts a portion of the first light beam to electric power for powering the field station. The field station demodulates an AC component superimposed on the light it receives to produce an AC electric signal for control of the field station. Optical transmitting and receiving functions in the field station are preferably combined into an integrated opto-electric and electro-optic converter (O-E and E-O converter). The O-E and E-O converter is preferably an integrated circuit.

Abstract: A rotatable polygon mirror comprising a transparent regular polygonal cylinder having the sides of a regular polygon. The sides are rotationally symmetrical with one another relative to a rotating axis of the transparent regular polygonal cylinder. The transparent regular polygonal cylinder has inner surfaces in the body of the transparent regular polygonal cylinder which correspond to the respective sides of the regular polygon, where the inner surfaces consist of total internal reflection surfaces.

Abstract: An optical switch having two spherical or elliptical corner-reflecting surfaces provided in a light-conducting member, a shutter to open and close a light path between the corner-reflecting surfaces, and focusing lenses to focus the incident beam from an emitting optical fiber and to focus the emitting beam from the light-conducting member to a primary receiving optical fiber. Because almost all the beam transmitted through the light-conducting member is focused at one point in an air gap in which the shutter moves, the optical switch can transmit the beam with high efficiency without leakage to the outside, and a small stroke of the shutter is sufficient to completely transmit or stop the beam.

Abstract: An optical frequency filter for selectively blocking or transmitting an amplitude-modulated optical signal. In a first embodiment of the invention, an optical coupler adds two optical inputs. The output of the optical coupler is delayed and attenuated and then applied to the input of an optical splitter. One output port of the optical splitter is applied to one input port of the optical coupler, with the optical signal to be filtered applied to the other input port of the coupler. The filtered output signal is produced at the second output port of the splitter. In a second embodiment, the delay and attenuation are performed between the output of the splitter and the input of the coupler. In a third embodiment, the signal to be filtered is applied to the input port of an optical splitter. One of the output ports of the splitter is coupled through a delay to one input port of an optical combiner, while the other output port of the splitter is delayed and coupled to the other input port of the coupler.

Abstract: The surface condition of a product being checked is determined by viewing the product with a raster-scanned television camera, or its equivalent and, on a horizontal-line-by-horizontal-line basis detecting the number of points in the video envelope which have a zero slope (a derivative of "zero") and, from such information generating a reject signal if the number of points exceeds one.

Abstract: An automated pattern inspection system comprising first means for measuring an area value of an object digitized pattern, second means for computing a first square value of a boundary length from the area value, third means for detecting a boundary of the object digitized pattern, fourth means for computing a second square value of a length of the boundary detected by the third means, fifth means for computing a subtraction value between the first square value from the second means and the second square value from the fourth means, and sixth means for comparing the subtraction value from the fifth means with a reference level, whereby a condition of defect in the pattern is evaluated. According to this invention, any defect in an object pattern, regardless of its size, can be detected with a high speed operation, since this system does not require a square root extraction process.