Abstract: An ultraviolet detector has a wavelength conversion element 1 of a length in an incident direction of UV light 2 set longer than the direction orthogonal to the incident angle, and a light receiving element 3 arranged at a side plane 1a of wavelength conversion element 1. Unconverted ultraviolet does not exit wavelength conversion element 1, and is propagated downwards to be attenuated. Visible light having the wavelength converted in wavelength conversion element 1 is propagated in all directions and received at light receiving element 3. Light receiving element 3 detects the quantity of light according to the incident amount of ultraviolet. As a result, the detection sensitivity is ensured and degradation of the light receiving element caused by ultraviolet radiation does not occur.

Abstract: An improved semiconductor construction and method of fabrication having a luminous element for emitting light is provided composed of a layer having a pn junction formed with a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type on an upper portion of a luminescent layer. In one portion of the above-described layer, an area for a current path consisting of the second conductivity type is formed extending from the second semiconductor layer to the first semiconductor layer. An ohmic contact electrode is then created covering substantially the entire upper surface of the second semiconductor layer with the exception of the area defined for the current path.

Abstract: In a ridge waveguide-type semiconductor light-emitting device, a buried layer is composed of a high-resistance semiconductor material (e.g., amorphous silicon), thereby improving the heat-dissipating characteristic and prolonging lifetime. The buried layer is made higher than the top surface of the ridge, the top surface of the ridge is situated in the resulting recess, and an electrode is formed from the top surface of the ridge to the top surface of the surrounding buried layer to cover the entirety of these surfaces. Making the buried layer higher than the top of the ridge prevents an electrical short circuit for being caused by an electrically conductive bonding agent used in junction-down mounting.

Abstract: The invention provides a displacement sensor comprising a light-emitting element for projecting a detection light towards an object in a substantially perpendicular direction, a condensing element for condensing a reflected light from the object, and a position sensitive device with its light-receiving surface disposed in parallel with the axis of the detection light. A positioning apparatus employing the above displacement sensor is also disclosed.

Abstract: In a reflective photosensor in which a light emitting element and a light receiving element are disposed in a mold resin, a planar optical element (micro Fresnel lens) including a first lens section for projecting a light emitted from the light emitting element toward a sense object in an external space and a second lens section for introducing a reflection light reflected from the sense object to the light receiving element is arranged in the mold resin. Favorably, the light emitting element is a light emitting diode of an edge emitting type and is set in a posture in which the element lies on its side. A reflection mirror is disposed in the model resin to introduce a light emitted from the light emitting diode to the first lens section.

Abstract: In a ridge waveguide-type semiconductor light-emitting device, a buried layer is composed of a high-resistance semiconductor material (e.g., amorphous silicon), thereby improving the heat-dissipating characteristic and prolonging lifetime. The buried layer is made higher than the top surface of the ridge, the top surface of the ridge is situated in the resulting recess, and an electrode is formed from the top surface of the ridge to the top surface of the surrounding buried layer to cover the entirety of these surfaces. Making the buried layer higher than the top of the ridge prevents an electrical short circuit for being caused by an electrically conductive bonding agent used in junction-down mounting.