Abstract: A positron-computed tomograph device is enabled to suppress the noise component of data for attenuation correction by continuing measurement of the relative angle between a gamma ray source for attenuation correction and detector pair out of a plurality of detectors thereby determining whether or not, at a given moment, the gamma ray source is present within the zone of measurement allocated for a specific detector pair which has detected coincidence and, when the determination ascertains that the source is not present in the aforementioned zone of measurement, avoiding measurement of coincidence or preventing data on coincidence from being stored in a memory.

Abstract: A light beam scanning apparatus projects a light beam swept by a light scanner to a spherical mirror and scans by a light beam spot reflected and focused by the spherical mirror a surface of an object arranged to oppose to the spherical mirror at a position spaced from the spherical mirror by a distance equal to a focal distance f of the spherical mirror. An optical path length between the light scanner and the spherical mirror is set to 0.78 f-0.84 f to minimize a curvature of field (circle of confusion).

Abstract: An apparatus for a detecting the location of incident radiation comprises at least one pair of assembly comprised of a scintillation crystal consisting of a plurality of crystal segments, a pair of photo-multiplier tubes optically coupled to the scintillation crystal so as to be able to detect a scintillation produced in any one of these crystal segments. These plural crystal segments are coupled to each other in such manner that any scintillation produced in any single crystal segment will cause the photo-multiplier tubes to deliver substantially a same output irrespective of the illuminating position within this crystal segment, and also that scintillations produced in the respective crystal segments will cause the photo-multiplier tubes to deliver outputs which are different in level for the respective crystal segments.

Abstract: An apparatus for effecting positron emission computed tomography comprises rows of a plurality of arrays of detectors arranged rotatably around a center of rotation in such way that at least one of the detectors in each array is disposed at an irregular position relative to the rest of detectors in the array, and that, for each revolution of the row through an angle of 360.degree./n (wherein: n represents an odd number of 3 or larger), each array of detectors will assume exactly the position occupied by its adjacent array till the revolution takes place.

Abstract: An apparatus for optically transmitting signals from a rotatable body to a stationary side or vice versa in a non-contact manner, includes a plurality of light emitting elements excited by a PCM signal from a signal source and a plurality of light receiving elements disposed in opposition with the light emitting elements for receiving light therefrom. A plurality of sets each including plural light receiving or emitting elements are provided at the stationary side in association with the respective light emitting or receiving elements disposed at the rotatable body side. Alternatively, a plurality of sets each including plural light emitting elements are provided at the rotatable body side in association with the respective light receiving elements disposed at the stationary side. The elements in such plural sets are selected in accordance with the rotation of the rotatable body.

Abstract: In a radiation detector including a radiation sensitive scintillator and a photo-electric conversion element, a film of silicon nitride providing a modified refractive index is interposed between the scintillator and the photo-electric conversion element.

Abstract: A scanner for positron emission computed tomography comprising a rotary member rotatable within the plane of a slice about an axis lying perpendicular to this plane and having means for accommodating a subject for examination, a drive means for rotating this rotary member within the plane of slice, and a plurality of radiation detectors provided on the rotary member so as to substantially face each other relative to the subject to be examined, in which the radiation detectors are disposed so that at least some of them are either positioned with irregular spacing relative to each other, or positioned at irregular distances from the axis of rotation.

Abstract: A self-luminescent light source for a liquid crystal display watch characterized by comprising a fluorescent substance layer which has a light reflectivity and which contains radioactive element promethium (.sup.

Abstract: A self-luminescent light source for a liquid crystal display watch characterized by comprising a fluorescent substance layer which has a light reflectivity and which contains a radioactive substance in at least a part thereof, a reflective layer which is disposed on one surface of the fluorescent substance layer and which serves to reflect and scatter fluorescence from the fluorescent substance layer, a case which is disposed on the side of the reflective layer remote from the fluorescent substance layer and which serves to perform shielding from radiation given out from the radioactive substance, and a cover which is disposed on the side of the fluorescent substance layer remote from the reflective layer and which serves to absorb the radiation given out from the radioactive substance and to transmit the light from the fluorescent substance layer.

Abstract: Apparatus for inspecting pipes in a plant, comprising an elongate inspection head portion which is provided with an optical system for receiving an inspection image by approaching an inner surface of a pipe being an object to-be-inspected; at least one proximity sensor which is disposed in the inspection head portion in order to detect a relative distance between the inspection head portion and the proximate object; a positioning mechanism which consists of a plurality of driving shafts for advancing or retreating, rotating, and revolving the inspection head portion; a control device which is capable of programmed operation and which drives and controls the positioning mechanism in a predetermined operation sequence programmed in advance; a data storage device which stores positional data of the respective driving shafts of the positioning mechanism; and an image processor which is disposed at a position remote from the inspection head portion and which reconstructs the inspection image from video signals; th

Abstract: A liquid crystal display device, especially, for use in a liquid crystal display watch is disclosed, which is provided with a liquid crystal display element and a reflector comprising a luminescent phosphor, and only in a limited partial area of the reflector corresponding to a specified display portion which should be visible in the dark or at night in the whole time display area of the liquid crystal display element, the luminescent phosphor includes a radioactive nuclide such as promethium (.sup.147 Pm) or tritium (.sup.3 H).

Abstract: In an optical system which is mounted on and used with an image pickup device for observing an object including a high brightness area therein, a pinhole is provided between the object and an imaging lens for separating the paths of the light rays from respective points of the object, and a filter which attenuates light from the high brightness area of the object which is separated by the pinhole.

Abstract: A scintillator for a gamma ray camera constituted by a crystal of NaI (Tl) having a surface roughness of less than 400 grit and a thickness of less than approximately 9 mm.

Abstract: A scintillator for a gamma ray camera includes a pair of crystals mechanically pressed together. The surfaces of the crystals are roughened so as to form a photo-diffuser for the light generated as a result of scintillation.

Abstract: In forming a film of a purposive substance on a substrate by a chemical vapor deposition (CVD), the size of the film-forming substance particles formed in a reactor is detected as an electrical signal and flow rates of respective gases introduced into the reactor are controlled in response to this electrical signal. According to this control method, the fogging phenomenon owing to formation of the film-forming substance in the gas flow can be effectively prevented.