Rohm Co., Ltd.

Yuichiro Nakata

Yoshitsugu Uedaira

Junji Fujino

Shinichi Otsuka

Masahide Tanaka

Takeshi Yoshida

Yoshihiro Tada

Nobuyuki Yamada

Takuya Tsuchikawa

A light emitting unit emits light including first light and second light. A light receiving unit outputs a signal of a level in accordance with intensity of incoming light. A first optical sensor is configured to outputs a first signal of a level in accordance with intensity of the first light entering the light receiving unit. A second optical sensor outputs a second signal of a level in accordance with intensity of the second light entering the light receiving unit. Based on the second signal, a controller determines whether or not the living body information sensor and a surface of the living body are in close contact with each other. The controller generates the information related to the living body based on the first signal obtained when the living body information sensor and the surface of the living body are in close contact with each other.

Living body information sensor

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.

Mobile device

An optical sensor device includes at least two light receiving units in which a plurality of types of light receiving elements is integrated in the same vertical structure. In addition, the optical sensor device further includes a switch unit configured to select at least one of the light receiving elements in each of the light receiving units in a time-division manner.

Optical sensor device

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.

Semiconductor device and electronic apparatus employing the same

The calculation device () 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 (through) 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.

Calculation device, movement detection device, and electronic instrument

In an illuminance sensor, a photoelectric converter () 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 () obtains illuminance based on the sum of the positive currents among the output currents of the three photosensors (PS).

Illuminance sensor, and electronic equipment and semiconductor device using the same

In an ambient light sensor according to the present invention, a current amplification portion which amplifies a light current obtained by a light receiving portion to generate an output signal includes: a current amplification stage that has: a first current mirror amplifier which is composed of a bipolar transistor, and a second current mirror amplifier which is composed of a field effect transistor connected in parallel with the first current mirror amplifier; and a changeover control circuit which monitors an amplified current input into the current amplification stage, and performs changeover control of the first and second current mirror amplifiers according to a value of the amplified current.

Ambient light sensor

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. This offers a wider input dynamic range combined with an enhanced minimum resolution without requiring complicated external control, and in addition allows measurement to be performed in less time.

Growing community of inventors

Kyoto, Japan

Yuichiro Nakata