Abstract: An improved diaphragm vacuum gauge including a sensor chip that includes a first electrode provided on a base and a second electrode provided on a diaphragm so as to face the first electrode, the diaphragm and the base being disposed with a gap therebetween, and in which a distance between the first electrode and the second electrode changes in accordance with displacement of the diaphragm caused by pressure of a measurement target medium. The diaphragm vacuum gauge further includes an operational amplifier that converts a current output from the first electrode to a voltage and amplifies the voltage, and a coaxial cable that connects the first electrode and the operational amplifier with each other. Further, the first electrode is connected to a virtual ground of the operational amplifier by a core wire of the coaxial cable.

Abstract: An improved diaphragm vacuum gauge includes a pressure receiving unit having an electrical property that changes in accordance with displacement of a diaphragm caused by pressure of a measurement target medium; a heater that heats the pressure receiving unit; a temperature sensor that measures a temperature of the pressure receiving unit; a pressure measurement unit that converts a change in the electrical property of the pressure receiving unit to a pressure measurement value; a storage unit that stores a plurality of heating temperature settings; a heating temperature setting unit that selects one heating temperature setting from among the plurality of heating temperature settings in accordance with a digital input signal that is externally input; and a controller that controls power supply to the heater based on the temperature measured by the temperature sensor and the heating temperature setting selected by the heating temperature setting unit.

Abstract: A diaphragm vacuum gauge includes: a sensor chip that includes a first electrode provided on a base and a second electrode provided on a diaphragm so as to face the first electrode, the diaphragm and the base being disposed with a gap therebetween, and in which a distance between the first electrode and the second electrode changes in accordance with displacement of the diaphragm caused by pressure of a measurement target medium; an operational amplifier that converts a current output from the first electrode to a voltage and amplifies the voltage; and a coaxial cable that connects the first electrode and the operational amplifier with each other. The first electrode is connected to a virtual ground of the operational amplifier by a core wire of the coaxial cable.

Abstract: A diaphragm vacuum gauge includes: a pressure receiving unit having an electrical property that changes in accordance with displacement of a diaphragm caused by pressure of a measurement target medium; a heater that heats the pressure receiving unit; a temperature sensor that measures a temperature of the pressure receiving unit; a pressure measurement unit that converts a change in the electrical property of the pressure receiving unit to a pressure measurement value; a storage unit that stores a plurality of heating temperature settings; a heating temperature setting unit that selects one heating temperature setting from among the plurality of heating temperature settings in accordance with a digital input signal that is externally input; and a control unit that controls power supply to the heater on the basis of the temperature measured by the temperature sensor and the heating temperature setting selected by the heating temperature setting unit.

Abstract: To provide an aspheric cemented lens which is easy to design and manufacture and has less aberration by using an inexpensive material such as a resin material. The aspheric cemented lens has at least three interfaces, when three interfaces are defined as a third interface, a second interface and a first interface in order from a light exit surface, chromatic aberration is corrected at the first interface and the second interface. The third interface is a hyperboloid or a surface close to a hyperboloid. When light is incident on the first interface parallel to the optical axis, the exit light from the third interface is converged to almost a single point. In order to correct chromatic aberration, the first interface and the second interface are curved surfaces.

Abstract: To provide an aspheric cemented lens which is easy to design and manufacture and has less aberration by using an inexpensive material such as a resin material. The aspheric cemented lens has at least three interfaces, when three interfaces are defined as a third interface, a second interface and a first interface in order from a light exit surface, chromatic aberration is corrected at the first interface and the second interface. The third interface is a hyperboloid or a surface close to a hyperboloid. When light is incident on the first interface parallel to the optical axis, the exit light from the third interface is converged to almost a single point. In order to correct chromatic aberration, the first interface and the second interface are curved surfaces.

Abstract: Among photodiodes used in an optical system for applying light to the entire chip, the conventional PIN photodiode has a problem that light should be applied only to a light reception surface in order to prevent degradation of light response and that positioning of the optical system is difficult. Moreover, in the mesa type PIN photodiode not requiring positioning of an optical system, disconnection failure is often caused by the mesa step. The present invention is made to solve the aforementioned problems, and its object is to provide a PIN photodiode having an improved light response and causing less disconnection failure of metal wiring and a light reception device using the PIN photodiode. The PIN photodiode of the present invention has a structure that the light reception surface is surrounded by a groove of a predetermined depth.

Abstract: A capacitance-type pressure sensor for measuring a change in a physical volume of a medium to be measured, by measuring two capacitances wherein the capacitances vary differently from each other in accordance with a change in the physical volume of the medium to be measured, provided with a function for measuring independent values for each capacitance and determining that there is an disconnect failure when at least one of these capacitance values falls below a capacitance value that indicates the normal operating range of the capacitance-type pressure sensor, to thereby provide a pressure sensor with higher reliability through performing the disconnect detection robustly.

Abstract: On an n-type GaN buffer layer serving as a common semiconductor layer, mesa regions are formed. The mesa region is formed of a semiconductor stack formed of an n-type GaN layer, an active layer and a p-type GaN layer. A current blocking region is not formed in the mesa region, and the mesa diameter of the mesa region is formed to be not more than 15 ?m. The mesa region is formed by selective growth. The mesa region without a surface damage allows sufficient constriction of current and an induced radiation of laser with low current.

Abstract: A photo coupler includes a semiconductor laser, a semiconductor light-receiver, a resin protector, a reflective film, a light pipe, and electrodes. The light pipe is made of resin, has a rectangular parallelepiped shape, and is provided so as to surround an outer circumferential portion of the semiconductor light-receiver. On a center portion of an upper surface of the light pipe, a recessed portion shaped in a frustum of quadrangular pyramid tapered toward the semiconductor light-receiver is formed. The reflective film is shaped in a frustum surface of pyramid tapered toward the semiconductor light-receiver, and is formed on side surfaces of the recessed portion.

Abstract: An optical element and an optical transmission member are fixedly secured onto a substrate so as to be coupled to each other. In this substrate, a through hole is formed between an optical element secured portion and an optical transmission member secured portion. In an attempt to assemble these optical transmission member and optical element so as to make the coupling at an optimal position, first, the position of the optical transmission member is adjusted to an optimal position, and after measuring the position by a laser micrometer, the optical transmission member is fixedly secured thereto by using a soldering material. Thus, measurements are again carried out by the laser micrometer to detect an amount of deviation from the measured value before the securing process, and the secured portion is again fused so that the optical transmission member is shifted based on the amount of deviation, and again fixedly secured thereon.

Abstract: An inventive optical communication module includes a substrate, a light receiving element disposed on one surface of the substrate for receiving light emitted from a transmission-side optical communication module, a block-shaped resin package which seals the one surface of the substrate and the light receiving element, and a lens disposed on a light incidence surface of the resin package opposite from a surface of the resin package contacting the substrate for converging the light emitted from the transmission-side optical communication module on the light receiving element. The resin package has a groove provided in a side face thereof intersecting the light incidence surface thereof.

Abstract: A photo coupler includes a semiconductor laser, a semiconductor light-receiver, a resin protector, a reflective film, a light pipe, and electrodes. The light pipe is made of resin, has a rectangular parallelepiped shape, and is provided so as to surround an outer circumferential portion of the semiconductor light-receiver. On a center portion of an upper surface of the light pipe, a recessed portion shaped in a frustum of quadrangular pyramid tapered toward the semiconductor light-receiver is formed. The reflective film is shaped in a frustum surface of pyramid tapered toward the semiconductor light-receiver, and is formed on side surfaces of the recessed portion.

Abstract: A light-emitting module includes a substrate, multiple light-emitting devices arranged thereon, and a package enclosing the multiple light-emitting devices. The package has multiple optical devices corresponding to the multiple light-emitting devices that converge and emit rays of light emitted from each of the light-emitting devices. When the outgoing rays of light emitted from the light-emitting device is extended toward the substrate, the package has virtual light-emitting regions spaced farther from the optical devices than the respective light-emitting devices, and the virtual light-emitting regions are located almost at the same position.

Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.

Abstract: On a semiconductor substrate (1), a double hetero structure portion (6) in which an active layer (4) having smaller band gap is sandwiched between semiconductor layers (3, 5) having larger band gap than that of the active layer (4) is formed. A light reflection film (9) is formed at least a part of side walls of the double hetero structure portion (6). As a result, a semiconductor light emitting device that light which leaks from side wall of light emitting area in a chip is reduced and emission light can be outputted efficiently can be obtained.

Abstract: An optical element and an optical transmission member are fixedly secured onto a substrate so as to be coupled to each other. In this substrate, a through hole is formed between an optical element secured portion and an optical transmission member secured portion. In an attempt to assemble these optical transmission member and optical element so as to make the coupling at an optimal position, first, the position of the optical transmission member is adjusted to an optimal position, and after measuring the position by a laser micrometer, the optical transmission member is fixedly secured thereto by using a soldering material. Thus, measurements are again carried out by the laser micrometer to detect an amount of deviation from the measured value before the securing process, and the secured portion is again fused so that the optical transmission member is shifted based on the amount of deviation, and again fixedly secured thereon.

Abstract: A light source device for a laser beam printer in which a semiconductor laser is driven with a pulse current having a minimum pulse width at the ON time on the order of milliseconds or less is provided, wherein the semiconductor laser is formed so that either the rate of change at the rise portion of the pulse current becomes ±8% or less or the semiconductor laser is excited in a multiple mode in the vicinity of the threshold value of the oscillation, and the semiconductor laser oscillates in a single mode at a current separated from the threshold value, by adjusting of at least one of the width w of a stripe groove (7a) of the current block layer, the composition of clad layers (5), the distance d between the current block layer (7) and the active layer (4), the composition of the current block layer (7) and the formation of a light absorption layer into the current block layer (7).

Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.

Abstract: On a semiconductor substrate (1), a double hetero structure portion (6) in which an active layer (4) having smaller band gap is sandwiched between semiconductor layers (3, 5) having larger band gap than that of the active layer (4) is formed. A light reflection film (9) is formed at least a part of side walls of the double hetero structure portion (6). As a result, a semiconductor light emitting device that light which leaks from side wall of light emitting area in a chip is reduced and emission light can be outputted efficiently can be obtained.