Abstract: A voltage clamp circuit includes a power supply, a first element connected with the power supply to output a constant current, a third element configured to allow a current to pass through when a voltage of a predetermined value or more is applied; and a second element configured to output a voltage according to a voltage generated by the first and third elements.

Abstract: An oscillator includes a reference voltage generator, an oscillation element configured to oscillate by either a drive voltage or a drive current and output an oscillation signal, a peak hold element configured to detect a peak level of the oscillation signal for output; and a controller configured to increase or decrease the drive voltage or drive current in accordance with the reference voltage generated by the reference voltage generator and the peak level output from the peak hold element.

Abstract: A sheet material identification device includes a humidity adjuster, a detector, and a controller. The humidity adjuster adjusts the humidity of a sheet material by causing the sheet material to either release or absorb moisture. The detector detects the humidity of the sheet material before and after the adjustment of the humidity. The controller calculates a first difference in humidity of the sheet material before and after the adjustment of the humidity, and identifies the type of sheet material on the basis of the first difference.

Abstract: An operation input system and method are provided. The operation input system includes protrusion members arranged in accordance with a predetermined rule along a flat surface. The distal end portions of the protrusion member are able to protrude from the flat surface. The system also includes a protrusion control section that controls a protrusion height of each of the protrusion members and a command reception section that receives input of a command for a value of an adjustment amount. The protrusion control section causes a plurality of the protrusion members disposed along a predetermined reference direction in a set region set on the flat surface to protrude and the command reception section sets a value of the adjustment amount corresponding to a position of the protrusion members along the reference direction.

Abstract: An oscillator includes a reference voltage generator, an oscillation element configured to oscillate by either a drive voltage or a drive current and output an oscillation signal, a peak hold element configured to detect a peak level of the oscillation signal for output; and a controller configured to increase or decrease the drive voltage or drive current in accordance with the reference voltage generated by the reference voltage generator and the peak level output from the peak hold element.

Abstract: Map image display devices, methods, and programs display a map image in a map display are, and at a prescribed timing, change to a first display mode in which an auxiliary image different from the map image is displayed in a specific area that is part of the map display area, and a portion of the map image corresponding to a first target area is displayed in a part of the display area that excludes the specific area. In response to a prescribed user operation, the devices, methods, and programs read map data of a second target area adjacent to the first target area, and change to a second display mode in which the auxiliary image is removed from the specific area and the map image is expanded into the specific area based on the map data of the second target area.

Abstract: A voltage clamp circuit includes a power supply, a first element connected with the power supply to output a constant current, a third element configured to allow a current to pass through when a voltage of a predetermined value or more is applied; and a second element configured to output a voltage according to a voltage generated by the first and third elements.

Abstract: A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.

Abstract: A disclosed laser diode driving circuit causes a laser diode to emit light by varying a current value of a current source in accordance with a control signal input externally and supplying a current that is the same as or proportional to the current value to the laser diode. The driving circuit includes correction circuitry for generating a reference forward voltage as a reference for the laser diode in accordance with a predetermined driving current for driving the laser diode, generating a forward voltage for the laser diode in accordance with the predetermined driving current, and correcting a current supplied to the laser diode so that the forward voltage becomes the same as the reference forward voltage.

Abstract: A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.

Abstract: A disclosed laser diode driving circuit causes a laser diode to emit light by varying a current value of a current source in accordance with a control signal input externally and supplying a current that is the same as or proportional to the current value to the laser diode. The driving circuit includes correction circuitry for generating a reference forward voltage as a reference for the laser diode in accordance with a predetermined driving current for driving the laser diode, generating a forward voltage for the laser diode in accordance with the predetermined driving current, and correcting a current supplied to the laser diode so that the forward voltage becomes the same as the reference forward voltage.

Abstract: A disclosed laser diode driving circuit causes a laser diode to emit light by varying a current value of a current source in accordance with a control signal input externally and supplying a current that is the same as or proportional to the current value to the laser diode. The driving circuit includes correction circuitry for generating a reference forward voltage as a reference for the laser diode in accordance with a predetermined driving current for driving the laser diode, generating a forward voltage for the laser diode in accordance with the predetermined driving current, and correcting a current supplied to the laser diode so that the forward voltage becomes the same as the reference forward voltage.

Abstract: A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.

Abstract: An optical semiconductor device includes an SiC substrate having an n-type conductivity, and an AlGaN buffer layer having an n-type conductivity formed on the SiC substrate with a composition represented as AlxGa1-xN, wherein the AlGaN buffer layer has a carrier density in the range between 3×1018–1×1020 cm?3, and the compositional parameter x is larger than 0 but smaller than 0.4 (0<x<0.4).

Abstract: A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.

Abstract: A disclosed laser diode driving circuit causes a laser diode to emit light by varying a current value of a current source in accordance with a control signal input externally and supplying a current that is the same as or proportional to the current value to the laser diode. The driving circuit includes correction circuitry for generating a reference forward voltage as a reference for the laser diode in accordance with a predetermined driving current for driving the laser diode, generating a forward voltage for the laser diode in accordance with the predetermined driving current, and correcting a current supplied to the laser diode so that the forward voltage becomes the same as the reference forward voltage.

Abstract: A lateral mode controlling layer made of AlN having a thickness of more than 0 nm but less than 300 nm is formed in at least one cladding layer of an n-type cladding layer and a p-type cladding layer or formed between the at least one cladding layer and the active layer. Also, a mask layer is formed on a substrate, then an AlN layer is formed to cover it, and then the AlN layer is lifted off by using a solution for etching. the mask layer. Accordingly, lateral mode control of the group III-V compound semiconductor laser can be facilitated, the aspect ratio of the beam shape can be improved, and the damage caused by the Al layer growth and the patterning can be reduced.

Abstract: There are provided a semiconductor laser, a semiconductor light emitting device, and methods of manufacturing the same wherein a threshold current density in a short wavelength semiconductor laser using a nitride compound semiconductor can be reduced. An active layer is composed of a single gain layer having a thickness of more than 3 nm, and optical guiding layers are provided between the active layer and cladding layers respectively.

Abstract: An optical semiconductor device includes an SiC substrate having an n-type conductivity, and an AlGaN buffer layer having an n-type conductivity formed on the SiC substrate with a composition represented as AlxGa1−xN, wherein the AlGaN buffer layer has a carrier density in the range between 3×1018−1×1012cm−3, and the compositional parameter x is larger than 0 but smaller than 0.4 (0<x<0.4).

Abstract: An intensity controlling circuit device can correct variation in intensity of light beams, due to tolerance occurred in each of a plurality of LED-array chips, emitted by LEDs provided in each of the LED-array chips. The intensity controlling circuit device is connected to at least one LED-array chip comprising a plurality of LEDs and slave transistors corresponding to each of the LEDs. The intensity controlling circuit device comprises an intensity controlling circuit connected to the respective LED-array chip. The intensity controlling circuit comprises a first transistor provided between a power source and a constant current generating unit so as to supply a current to the LED-array chip, and an intensity adjusting unit having a second transistor connected to the first transistor in parallel and a controlling unit for controlling the on/off state of the second transistor.