Abstract: A high frequency module is provided with a resistor array layer with interconnections, in which a plurality of resistor elements having a prescribed resistance value are formed as an array, and in which an interconnection pattern for providing electrical connection to each resistor element is formed in advance. Additionally, a capacitor array layer with interconnection in which a plurality of capacitor elements having a prescribed capacitance value are formed as an array and an interconnection pattern for providing electrical connection to each capacitor element is also formed in advance for later use. A desired circuit constant is obtained by providing interconnections among the plurality of resistor elements and among the plurality of capacitor elements, respectively, in any given combination by simply modifying the respective interconnection patterns instead of the entire module.

Abstract: A smaller oscillator module enables oscillation frequency to be adjusted from the back after assembly is finished. The oscillator has oscillator circuit components mounted on the front of a circuit board having an internal dielectric layer, a back conductor layer covering a major part of the back of the circuit board, and at least a part of an inductor element of the oscillator circuit disposed internally with a part of an intervening dielectric layer from the back conductor layer. A slit or pinhole is formed in the back conductor. The oscillation frequency can then be adjusted after assembly is completed by emitting a trimming laser through this slit or pinhole to change the inductance by partially removing the dielectric layer and inductor element.

Abstract: An impedance matching device includes a variable capacitor constituted by a non-linear dielectric thin film and an upper electrode disposed on a lower electrode formed on a substrate. The non-linear dielectric thin film is formed by a deposition, screen-printing, electroplating, or other technique, and changes its relative dielectric constant according to applied voltage. Therefore, the capacity of the variable capacitor is controlled and the impedance is matched, by simply controlling the applied voltage across the non-linear dielectric thin film. Consequently, the arrangement makes it possible to cut down the impedance matching device in size and cost, compared to an arrangement incorporating a capacitor and a coil for adjustment, effects a much simpler matching operation, and facilitates a manufacturing process.

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: There is provided an inexpensive light emitting display device which has a simple wiring structure and produces a bright screen display. A photo-transistor is connected in series with a light emitting diode. The photo-transistor is arranged so that light emitted from the light emitting diode enters into the photo-transistor. There is provided an optical guide for guiding a data signal light to the photo-transistor and an optical guide for guiding a scanning signal light to the phototransistor. Further, an optical control section has a laser diode array, a lens array, and a deflection mirror. The above-mentioned arrangement obviates the need of an electric wiring for a data signal and a scanning signal, and is able to turn on the photo-transistor with the emission light from the light emitting diode and makes the photo-transistor self-hold its conductive state.

Abstract: A hyper-resolution optical device which can focus a beam of light to a diameter less than the diffraction limit. The optical device has an optical system disposed on a transmissive substrate. One component in the optical system is a hyper-resolution optical component which passes or reflects light and which has a central portion which does not pass or reflect light, respectively. The hyper-resolution optical component can be integrated with the transmissive substrate. Such optical devices are particularly suitable for optical pick-up devices, laser printers, sensors.

Abstract: A reflective type photointerrupter including: a resin case formed with a light emitting chip mounting recess and a light receiving chip mounting recess; a metallic deposit wiring formed in the recesses; and a light emitting chip and a light receiving chip respectively mounted on the light emitting chip mounting recess and the light receiving chip mounting recess and sealed with a resin material; the recesses being arranged in side-by-side relation and partitioned by an intermediate wall.