Abstract: Disclosed is a photodetector with a multilayer filter. A light-receiving substrate is mounted on a recessed portion of a ceramic stem. An electrode pad is formed on a P-type layer of the light-receiving substrate while another electrode pad is formed on an N-type layer of the light-receiving substrate. An optical multilayer filter is formed on the light-receiving substrate except the regions of the electrode pads. Further, an epoxy transparent resin is poured into the recessed portion of the stem and then cured, so that a resin portion to cover the light-receiving substrate is formed. The optical multilayer filter is formed of amorphous low refractive index films made of SiC.sub.2 and amorphous high refractive index films made of TiO.sub.2. The amorphous high and low refractive index films are alternately stacked.

Abstract: A method for manufacturing an optical memory element including the steps of disposing a resist film on a substrate, placing a photo-mask carrying a guide groove pattern on the resist film so as to position the photo-mask over a predetermined position of the substrate, forming a guide groove pattern latent image on the resist film, developing the guide groove pattern latent image formed on the resist film, conducting an etching operation through the developed guide groove pattern as to form guide grooves in the substrate, removing the resist film from the substrate, and disposing a recording medium layer on the substrate having the guide grooves formed therein.

Abstract: A tracking system for positioning a light spot onto a magneto optic or optical disc having a beam guide track preformatted thereon comprises a main light beam and two auxiliary light beams, and a circuit for subtracting a low frequency component of a difference between the tracking error signals, detected by the respective auxiliary light beams and the main light beam, from a tracking error signal detected by the main light beam.

Abstract: A method for manufacturing an optical memory element including the steps of disposing a resist film on a substrate, placing a photo-mask carrying a guide groove pattern on the resist film so as to position the photo-mask over a predetermined position of the substrate, forming a guide groove pattern latent image on the resist film, developing the guide groove pattern latent image formed on the resist film, conducting an etching operation through the developed guide groove pattern as to form guide grooves in the substrate, removing the resist film from the substrate, and disposing a recording medium layer on the substrate having the guide grooves formed therein.

Abstract: A tracking system for positioning a light spot onto a magneto-optic disc having a beam guide track preformatted thereon, includes a main light beam and two auxiliary light beams, and a circuit for switching between a low frequency component of a tracking error signal, detected by respective auxiliary light beam detectors, and a tracking error signal detected by a main light beam detector.

Abstract: An image readout element of an image readout sensor for reading image information comprises an insulation substrate which transmits light, a pair of electrodes opposite to each other which are deposited on the substrate, and a photoconductive layer coated on the substrate and the pair of electrodes, the photoconductive layer comprising particles showing photoconductive characteristics and a resin material for dispersing and binding the photoconductive particles. There are provided a plurality of the sensor element in a single image readout sensor, and one of each pair of electrodes is arranged in parallel with one of the other pairs of electrodes.

Abstract: A two-dimensional image reading unit includes a semiconductor layer made of a photoelectric material having a pin structure, a plurality of transparent electrodes aligned parallel to each other and provided on one face of the semiconductor layer, and a plurality of opaque electrodes aligned parallel to each other and provided on the other face of the semiconductor layer such that the opaque electrodes intercept with the transparent electrodes. A photoelectric cell is defined at each crossing point of the transparent and opaque electrodes.

Abstract: A two-dimensional image read-out device comprising a photoconducting layer, a plurality of X stripe electrodes applied on one surface of the photoconducting layer and arranged parallel with each other, and a plurality of Y electrodes applied on the other surface of the photoconducting layer and arranged parallel with each other in a direction perpendicular to the X electrodes. Both the X and Y electrodes are made of electrically conductive material, and the X or Y electrodes through which light from an image enters are made of transparent or translucent material. The light-entering side of the two-dimensional image read-out device is covered with an opaque material which allows the passage of light only through the picture elements which are formed at the intersections of the X and Y electrodes.

Abstract: A two-dimensional image read-out device comprises an insulating substrate, a plurality of Y-line electrodes formed on the insulating substrate and arranged parallel with each other, a plurality of X-line electrodes formed over the insulating substrate and arranged parallel with each other in a direction perpendicular to the Y-line electrodes, a photoconductive layer interposed between the Y-line and the X-line electrodes, gate electrodes for selecting a pair of the Y-line and the X-line electrodes, and three scanning circuits for selecting some of the Y-line electrodes, and some of the X-line electrodes, and at least one of the gate electrodes, respectively.

Abstract: A two-dimensional image sensor includes a two-dimensional photoconductive layer. A flat common electrode is formed on one major surface of the two-dimensional photoconductive layer. A pin electrode array having a plurality of pin electrodes aligned in a first direction is disposed above a second major surface of the two-dimensional photoconductive layer. An optical fiber lens array is fixed to the pin electrode array in order to apply optical image onto the second major surface of the two-dimensional photoconductive layer at a same time when a high voltage is applied by the pin electrodes. A shift means is connected to the pin electrode array to shift the pin electrode array and the optical fiber lens array in a second direction which is perpendicular to the first direction. Electric current is obtained at the flat common electrode, which represents the optical image applied by the optical fiber lens array.

Abstract: The present disclosure is directed to a two-dimensional image readout device. The device includes a sensor device consisted of an insulating substrate, a plurality of parallel Y electrodes of conductor, a plurality of X electrodes disposed in a direction normal to the Y electrodes with a spacing therebetween and a photoconductive layer interposed in the spacing between the Y and X electrodes, at least one of the Y and X electrodes being made of transparent material. There are further provided an optical system for leading to a surface of the sensor device an image to be read out, a control circuit for scanning the photoconductive layer in association with guide operation for leading the image to the surface of the sensor device via the optical system while the electrodes are switched.