Abstract: A photodetection device of the present invention includes a semiconductor substrate which is defined such that a first light-receiving portion and a second light-receiving portion are spaced from one another, and an optical filter which is formed on the semiconductor substrate, and includes a first filter which is disposed so as to cover the first light-receiving portion, to selectively allow an optic element in a first wavelength band to transmit through, and a second filter which is disposed so as to cover the second light-receiving portion, to selectively allow an optic element in a second wavelength band different from the first wavelength band, to transmit through, and the optical filter has a filter laminated structure which is defined such that edge portions of the first filter and the second filter overlap one another on a boundary region between the first light-receiving portion and the second light-receiving portion.

Abstract: A visible light communication system comprising a first electronic device having a display part and a second electronic device 20 having a brightness sensor, visible light communication between the first electronic device and the second electronic device occurring as a result of the brightness sensor detecting visible light (solid arrow) output from the display part.

Abstract: The calculation device (36) according to the present invention receives a plurality of reflected light intensity information for indicating the intensity of each reflected light which reaches a single light receiver via a reflecting object, the reflected light having been emitted in sequence from a plurality of light emitters (31 through 33) provided in mutually different positions, computes a phase difference of an intensity variation which occurs among the reflected light, and determines a movement of the reflecting object on the basis of the calculation result.

Abstract: In an illuminance sensor, a photoelectric converter (1) includes three photosensors (PS), and each photosensor (PS) outputs a current as a difference between photocurrents generated in two photodiodes (PDA, PDB) having different light reception characteristics. Ratios between light receiving areas of the two photodiodes (PDA, PDB) in the three photosensors (PS) are different from each other, and the sum of positive currents among output currents of the three photosensors (PS) is constant for a given illuminance, regardless of the type of light source. A computation control unit (7) obtains illuminance based on the sum of the positive currents among the output currents of the three photosensors (PS).

Abstract: Disclosed is a semiconductor device, comprising a driver that causes first through third infrared LEDs to emit light sequentially at prescribed times; an infrared light sensor that receives infrared light that is emitted by the first through the third infrared LEDs and reflected by a reflecting object, and generates photoelectric currents at levels corresponding to the intensity of the received infrared light; an amplifier that generates first through third infrared light information, on the basis of the photoelectric current that is generated by the infrared light sensor, and which denote the intensity of the infrared light; an A/D converter; and a linear/logarithmic converter apparatus. It is thus possible to sense the movement of the reflecting object on the basis of the first through the third infrared light information.

Abstract: Disclosed is a mobile device comprising an acceleration detection unit for detecting acceleration relative to the device; a condition identification unit; and a power supply controller which determines, from a combination of the output of the acceleration detection unit and the output of the condition identification unit, whether or not to begin to supply power to the device.

Abstract: In an illuminance sensor, a photoelectric converter (1) includes three photosensors (PS), and each photosensor (PS) outputs a current as a difference between photocurrents generated in two photodiodes (PDA, PDB) having different light reception characteristics. Ratios between light receiving areas of the two photodiodes (PDA, PDB) in the three photosensors (PS) are different from each other, and the sum of positive currents among output currents of the three photosensors (PS) is constant for a given illuminance, regardless of the type of light source. A computation control unit (7) obtains illuminance based on the sum of the positive currents among the output currents of the three photosensors (PS).

Abstract: The calculation device (36) according to the present invention receives a plurality of reflected light intensity information for indicating the intensity of each reflected light which reaches a single light receiver via a reflecting object, the reflected light having been emitted in sequence from a plurality of light emitters (31 through 33) provided in mutually different positions, computes a phase difference of an intensity variation which occurs among the reflected light, and determines a movement of the reflecting object on the basis of the calculation result.

Abstract: An ambient light sensor (1) incorporated in electronic equipment includes a plurality of amplifiers (11, 12). Receiving signals (S1, S2) corresponding to the plurality of amplifiers (11, 12) respectively, the plurality of amplifiers (11, 12) vary an amplification factor. Depending on combination of the amplification factors (such as 10 and 1) of the plurality of amplifiers (11, 12), a current output from a photodiode (10) is amplified at any amplification factor, for example, of 1, 10, and 100. An appropriate amplification factor can thus be selected depending on a current output from the photodiode (10). In addition, a voltage (VOUT) output from the ambient light sensor (1) can be controlled such that it is within a widest input voltage range of an AD converter (21).

Abstract: An analog/digital converter has a charge circuit that has a charge capacitor storing an electric charge commensurate with an input current, and first and second discharge circuits that discharge the electric charge stored in the charge capacitor. While the charge capacitor is charged for a predetermined charge period, every time a predetermined amount of electric charge is stored in the charge capacitor, the electric charge stored there is discharged by the first discharge circuit. After the charge period, the electric charge remaining in the charge capacitor is discharged by the second discharge circuit. Based on the number of discharges performed by the first discharge circuit and the discharge duration of the second discharge circuit, a digital value of the voltage commensurate with the amount of electric charge with which the charge capacitor has been charged is outputted.

Abstract: An optical receiver is capable of minimizing fluctuations in the pulse width of an electrical signal rendered by converting an optical signal of broad-range illumination. The optical receiver includes a light-receiving element that receives an optical signal and converts the optical signal into a current; a bypass element through which a portion of the current of the light-receiving element flows; an impedance element that detects the remaining portion of the current of the light-receiving element and converts the remaining portion into a voltage signal; a voltage separation element interposed between the impedance element and the light-receiving element that separates the voltages on both sides thereof; and an automatic gain control (AGC) circuit to which the voltage signal from the impedance element is inputted and that controls the current flowing to the bypass element in accordance with the voltage signal.

Abstract: An analog/digital converter has a charge circuit that has a charge capacitor storing an electric charge commensurate with an input current, and first and second discharge circuits that discharge the electric charge stored in the charge capacitor. While the charge capacitor is charged for a predetermined charge period, every time a predetermined amount of electric charge is stored in the charge capacitor, the electric charge stored there is discharged by the first discharge circuit. After the charge period, the electric charge remaining in the charge capacitor is discharged by the second discharge circuit. Based on the number of discharges performed by the first discharge circuit and the discharge duration of the second discharge circuit, a digital value of the voltage commensurate with the amount of electric charge with which the charge capacitor has been charged is outputted.

Abstract: An optical receiver is capable of minimizing fluctuations in the pulse width of an electrical signal rendered by converting an optical signal of broad-range illumination. The optical receiver includes a light-receiving element that receives an optical signal and converts the optical signal into a current; a bypass element through which a portion of the current of the light-receiving element flows; an impedance element that detects the remaining portion of the current of the light-receiving element and converts the remaining portion into a voltage signal; a voltage separation element interposed between the impedance element and the light-receiving element that separates the voltages on both sides thereof; and an automatic gain control (AGC) circuit to which the voltage signal from the impedance element is inputted and that controls the current flowing to the bypass element in accordance with the voltage signal.