Abstract: A protection circuit for protecting a secondary battery includes a controller that closes a charging path for charging the secondary battery with a charger when a charge preventing condition is satisfied, the charging path being between a terminal of the secondary battery and an input-output terminal for connecting the charger and an electronic apparatus, opens the charging path when a discharging current from the secondary battery to the electronic apparatus is detected while the charge preventing condition is satisfied and the charging path is closed, and temporarily closes the charging path when a predetermined period of time passes after the charging path is opened, to determine whether the discharging current is flowing.

Abstract: A housing accommodates an optical waveguide substrate, plural signal light receiving elements, and a signal-light-level monitoring light receiving element. Signal light and locally oscillated light are input into optical waveguides in the optical waveguide substrate from a first end face of the optical waveguide substrate. The plural signal light receiving elements are disposed aligned on a side of a second end face opposite to a side of the first end face of the optical waveguide substrate. The signal-light-level monitoring light receiving element is disposed on a side of a third end face or a fourth end face between the first end face and the second end face of the optical waveguide substrate and at a position closer to the first end face than to the second end face.

Abstract: An optical receiver including a waveguide substrate including a first waveguide that transmits a main signal beam, a second waveguide that transmits a monitoring beam that has branched from the main signal beam, and a third waveguide that transmits an amplification beam to amplify the main signal beam; a light receiving device array including, integrally formed to the same substrate, a first light receiving device that detects the main signal beam and a second light receiving device that detects the monitoring beam; and a case that houses the waveguide substrate and the light receiving device array. The first light receiving device faces toward an end of the first waveguide, and the second light receiving device faces toward an end of the second waveguide.

Abstract: A protection IC connected to cell groups of a secondary battery assembly of a secondary battery connected in series and monitoring battery voltages of the cells in the cell groups, including terminals connected to connection points of the cells in the cell groups and both ends of the cell groups; a first alarm generating portion detecting an overvoltage by comparing voltages of the cells of the cell groups on both ends of the cells and generates the first alarm signal; and a second alarm generating portion detecting disconnection in connection points of the cells and disconnection between the connection points of the cell groups and the both ends and the terminals by detecting voltage drop or current decrement at the connection points of the cells of the cell groups and at one end of the cell groups in the cells, and generates a second alarm signal.

Abstract: Disclosed are a PLC-type delay demodulation circuit and a PLC-type optical interferometer capable of reducing the size of a PLC chip with respect to the arrangement of various kinds of light output waveguides. In a PLC-type delay demodulation circuit, arm waveguides of a first MZI and arm waveguides of a second MZI are formed so as to overlap each other in the same region of a planar lightwave circuit. The optical paths of the MZIs are arranged such that the propagation directions of two DQPSK signals branched by a Y-branch waveguide are opposite to each other.

Abstract: A semiconductor integrated circuit that protects a secondary battery by controlling an on/off status of a discharge control switch and a charge control switch includes an over discharge detection part configured to detect an over discharge condition based on a battery voltage of the secondary battery, a load removal detection part to detect whether a load connected to the secondary battery is removed based on a voltage of a load removal detection terminal connected to a negative electrode side of at least one of the load connected to the secondary battery and a battery charger through a resistor, an over discharge return part to return to a normal condition from the over discharge condition, and a control part to output a control signal for returning the over discharge condition to the normal condition to the over discharge return part upon detecting the load being removed in the over discharge condition.

Abstract: Disclosed are a PLC-type delay demodulation circuit and a PLC-type optical interferometer capable of reducing the size of a PLC chip with respect to the arrangement of various kinds of light output waveguides. In a PLC-type delay demodulation circuit, arm waveguides of a first MZI and arm waveguides of a second MZI are formed so as to overlap each other in the same region of a planar lightwave circuit. The optical paths of the MZIs are arranged such that the propagation directions of two DQPSK signals branched by a Y-branch waveguide are opposite to each other.

Abstract: A wavelength selective switch for suppressing degradation of pass band characteristics when the temperature rises. The wavelength selective switch includes a spectroscopic element for separating input light and providing angular dispersion depending on wavelengths, a collective lens for gathering light output from the spectroscopic element, and a movable reflection block which includes a plurality of mirrors arranged in the direction of angular dispersion made by the spectroscopic element, changes the angles of the mirrors in a direction differing from the direction of angular dispersion, and reflects the light coming from the collective lens. The collective lens is fixed at one end with respect to the direction of angular dispersion, expands with heat in a direction in which it is not fixed when the temperature rises, and outputs the light in a direction opposite to the direction in which the angle of light output from the spectroscopic element changes.

Abstract: An optical apparatus includes a collimation optical member for collimating and outputting input light, a condensing optical member for condensing light from the collimation optical member and a light blocking mask member provided at a place on an optical path of the input light for light blocking part of the input light, and enhances the degree of freedom in design of an optical system.

Abstract: There are provided methods and arrangements for communication in which, even in a case where an antenna that is not correctly connected is present in a wireless module provided with a plurality of antennas, high-performance data communication can be performed without using such antennas. RSSI values are detected from a plurality of receiving circuits of a wireless module, respectively, and a computer judges whether or not there is a significant difference between a first RSSI value detected from one receiving circuit and a second RSSI value detected from another receiving circuit. In a case where it is judged that there is the significant difference, the computer recognizes that the receiving circuit from which a larger RSSI value has been detected is connected to an antenna and the receiving circuit from which a smaller RSSI value has been detected is not connected to the antenna, and the receiving circuit recognized to be unconnected to the antenna is set to operation stop.

Abstract: There is provided a test apparatus for testing a plurality of devices under test. The test apparatus includes a signal input section that applies a test signal to the devices under test so as to cause the devices under test to concurrently output response signals, a combining section that generates a single combination signal by using the response signals output from the devices under test, and a judging section that judges whether the devices under test operate normally with reference to the combination signal.

Abstract: An optical device includes: an optical component; a case air-sealed, and made of metal, the optical component being secured within the case; and a lens provided within the case, and positionally adjusted in consideration of a deformation of the case air-sealed, light emitted from the optical component passing through the lens or light traveling to the optical component passing through the lens.

Abstract: A method for controlling power in a computer system having a network device and a wakeup function is disclosed. A determination is made whether or not the network device is in an associated state at the time when the computer system moves into a power saving mode. In response to a determination that the network device is not in the associated state, power supply is turned off from a power source to the network device. In response to a determination that the network device is in the associated state, power supply is continually provided from the power source to the network device.

Abstract: A wavelength dispersion compensation device includes an etalon 100 having a slab shape. Reflective films are formed on each side of the etalon 100. The reflective films respectively have predetermined reflectance. Reflectance of one of the reflective films differs according to a light incident angle by using a portion of light within a wavelength range to be used with which a filter characteristic in which transmittance rapidly changes is obtained.

Abstract: The present mirror device for suppressing PDL on the assumption of multiple modes of angles of input light and output light to movable mirrors with respect to the crystal axis of a crystal member at the time light passes through the crystal member. The mirror device includes a mirror system 2 and a flat-shaped crystal member 3 which is arranged in such a manner that a first angle is not larger than a second angle. The crystal member is constructed in such a manner that a third angle is substantially equal to a half of a fourth angle.

Abstract: The optical switch includes: a spectroscopic device which separates wavelength division multiplexed (WDM) light into its component wavelengths; and a plurality of movable reflectors, arranged in a spectral direction at different intervals, for reflecting light of an individual component wavelength separated by said spectroscopic device. With this optical switch, deterioration of the characteristic of the pass band is avoided, so that the pass band characteristic is increased.

Abstract: A wavelength selective switch of the present invention angularly disperses lights output from a plurality of input ports of an input and output optical system, to an X-direction, according to wavelength, by a diffraction grating to supply the dispersed lights to a condenser lens. The condenser lens is arranged so that a center axis thereof is shifted to the X-direction relative to an axis passing through the center of spreading angle to the X-direction of output beams from the diffraction grating, and accordingly, at a non-operating time, the light of each wavelength passed through the condenser lens is incident on each movable mirror being tilted by an offset angle corresponding to a shift amount of the condenser lens. As a result, it becomes possible to block the connection between an input side and an output side at the non-operating time without degrading the performance at an operating time.

Abstract: An optical apparatus includes a collimation optical member for collimating and outputting input light, a condensing optical member for condensing light from the collimation optical member and a light blocking mask member provided at a place on an optical path of the input light for light blocking part of the input light, and enhances the degree of freedom in design of an optical system.

Abstract: An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane.

Abstract: There is provided a test apparatus for testing a plurality of devices under test. The test apparatus includes a signal input section that applies a test signal to the devices under test so as to cause the devices under test to concurrently output response signals, a combining section that generates a single combination signal by using the response signals output from the devices under test, and a judging section that judges whether the devices under test operate normally with reference to the combination signal.