Abstract: A non-reciprocal unit and a parallel-surfaced flat birefringent plate are provided between incident side and outgoing side fiber collimators. The non-reciprocal unit is formed by disposing two tapered birefrigent plates, one on each side of a 45.degree. Faraday rotator consisting of a cylindrical permanent magnet and a magneto-optical element housed in the magnet. The optical axes of the parallel-surfaced flat birefringent plate and adjacent tapered birefringent plate are staggered from each other by 90.degree.. The thickness of the parallel-surfaces birefringent plate is set equal to the sum of the thicknesses of the two tapered birefringent plates.

Abstract: An optical information read/write apparatus that comprises a casing for installing an optical disk therein and a first movable unit having an objective lens for converging an optical beam on the disk. The lens center moves on a radial direction line originated from the disk center. A first fixed unit is disposed aside the disk in the casing. The fixed unit has an optical source for emitting the beam and constitutes a reading optical pickup in conjunction with the first movable unit. A second movable unit is disposed in the same half side of the disk as the first movable unit. The second movable unit has an objective lens for converging an optical beam on the disk. The lens center of the second unit moves on a radial direction line originated from the disk center. A second fixed unit is disposed aside the disk. The second fixed unit has an optical source for emitting the beam of the second movable unit and constitutes a writing optical pickup in conjunction with the second movable unit.

Abstract: A multi-beam optical pick-up for use in an optical disc system includes a light source for emitting two light beams which are focused onto an optical disc to form two light spots thereon. The pick-up also includes an optical system to receive light reflected from the optical system and to divide the reflected light into a first light beam and a second light beam. Also provided in the pick-up are a first detector for detecting an opto-magnetic signal and a focusing error signal from the first light beam and a second detector for detecting a tracking error signal for the two light spots formed on the optical disc with respect to a desired recording track thereof.

Abstract: An overwriting recorder includes a light intensity modulator for modulating a semiconductor laser beam with a signal to be recorded to obtain a light intensity corresponding to the signal, and at least one fixed-field generator for applying magnetic fields in mutally opposite directions to the disk at two respective positions thereon which are determined by the light intensity of the modulated laser beam. Information can be overwritten on the disk through light modulation.

Abstract: A coil device comprises a bobbin; one or more turns of wire wound on the bobbin to form a coil; coil terminals for leading out the coil by means of leads, the coil terminals having one end fixed on the bobbin and the other end formed in a hollow shape, respectively; end portions of the coil wound on the peripheral surfaces of the hollow parts of the coil terminals; and lead terminals fixed to the leads and inserted into the hollow parts to make electrical connection between the coil and the leads.

Abstract: A casing in the form of a slender hollow structure has a slit-shaped entrance aperture defined in an upper cover thereof and a slit-shaped exit aperture defined in a lower cover thereof. The casing houses a covex roof-shaped mirror having a convex reflecting surface, a lens array, a concave roof-shaped mirror array having an array of convex reflecting surfaces, and a spacer interposed between the concave roof-shaped mirror array and the lens array to keep them spaced apart. The upper and lower covers of the casing are integrally formed with or securely coupled to the spacer. A light shield plate lies between the corner of the convex roof-shaped mirror and the lens array, and a reflecting plate is mounted on the upper cover of the casing for reflecting light from a light source to an object to be imaged. A sensor for detecting the amount of light emitted from the light source is also mounted on the casing.

Abstract: A power load survey apparatus is disclosed with an electronic power sensor for detecting a power load in the form of a pulse signal, a collector cartridge detachably coupled to the electronic power sensor and having a memory for storing the pulse signal and the time of data collection. The time is obtained from a self-contained time keeping circuit. A memory and magnetic tape converting device is detachably coupled to the collector cartridge and includes a magnetic tape device for transferring and recording data from the memory of the electronic power sensor, and a standard clock 52. The time data obtained from the collector cartridge is time rectified to a standard time from the standard clock 52 each time the collector cartridge is coupled to the memory/magnetic tape converting device thereby insuring that the collector cartridge shows a correct time.

Abstract: First and second optical systems each comprise identical converging lenses which focus light images of an object onto identical photosensor arrays, the lenses being parallel. First and second mirrors reflect the light images from the respective lenses onto the respective arrays. The first mirror is fixed whereas the second mirror is rotatable. Where the second mirror is rotated to a position where the light images on the arrays are identical, the distance to the object is a function of the position of the second mirror which is predetermined by triangulation. As the second mirror is rotated through a predetermined range the arrays are strobed a predetermined number of times to produce analog signals having magnitudes corresponding to incident light. The respective analog signals are subtracted and the resulting difference signals compared with a previously minimum value. Each time the arrays are strobed a counter is incremented.