Kabushiki Kaisha Toshiba

Hiroshi Suzunaga

Yukiko Takiba

Shigeyuki Sakura

Hideyuki Mori

Atsushi Iwata

Osamu Takata

Masaru Numano

Atsushi Namai

Masahito Nishigoori

Hiroshi Shimomura

Miki Hidaka

Yukiko Kashiura

Hirofumi Kobayashi

Yoshitaka Murasaka

Miki Furuya

Toshifumi Imamura

Kazuya Matsumoto

A light receiving circuit includes an inverting amplification circuit, a first light receiving element, a first circuit, and a charging circuit. The inverting amplification circuit includes an input terminal and an output terminal. The first light receiving element is connected between the input terminal and a reference potential terminal. The first circuit includes a first resistor, a second resistor, a third resistor and a capacitor. The first resistor second resistor connected through a connection point. The first resistor is connected between the input terminal and the connection point, and the second resistor connected between the output terminal and the connection point. The third resistor is connected between the connection point and connection node, and the capacitor is connected between the connection node and the reference potential terminal. The charging circuit connected between the power supply terminal and the connection node.

Light receiving circuit and light coupling device

A light receiving element includes: a semiconductor layer; an insulating layer; an interconnect layer; and a film. The semiconductor layer includes a light receiving unit configured to convert a signal light incident on the light receiving unit into an electrical signal. The insulating layer is provided on the semiconductor layer. The interconnect layer is provided on the insulating layer. The film is provided on the insulating layer to cover the light receiving unit and be connected to the interconnect layer, the film being made of a metal or a metal nitride.

Light receiving element and optically coupled insulating device

A semiconductor circuit including an input terminal, an impedance converting portion configured to receive an input signal from the input terminal and to output an output signal corresponding to the input signal, an input impedance of the semiconductor circuit being higher than an output impedance of the semiconductor circuit, a detecting portion connected to a node between the input terminal and the impedance converting portion, and configured to detect whether the input signal is higher than a predetermined threshold, and a variable impedance connected to a reference voltage and the node, an impedance of the variable impedance configured to decrease after the input signal is detected as higher than the predetermined threshold.

Impedance converting circuit and electronic device

An optical signal receiving circuit, may include a first transimpedance amplifier configured to convert a first current signal into a first voltage signal, wherein the first current signal generated in a first photodiode, to which an optical signal is inputted; a second transimpedance amplifier configured to convert a second current signal into a second voltage signal, wherein the second current signal generated in a second photodiode, to which an optical signal is inputted; a noise detection circuit configured to detect a noise signal of the second voltage signal, and configured to shift at least one of the first voltage and the second voltage in order to widen a voltage difference between the first voltage signal and the second voltage signal when the noise signal of the second voltage signal is detected; and a first comparator having as inputs the first voltage signal and the second voltage signal, and configured to generate a digital signal based on the first voltage signal and the second voltage signal.

Optical signal receiving circuit

A semiconductor photosensor device includes a plurality of photodiode sections, a switch, and an output section is provided. The plurality of photodiode sections have different illuminance-output characteristics. The switch selects any one of the plurality of photodiode sections on the basis of an illuminance of incident light irradiated on the photodiode sections. The output section outputs an output signal from the selected photodiode section through the switch.

Semiconductor photosensor device with sensitivity region for wide dynamic range and information apparatus

According to the invention, there is provided a receiving apparatus including: a first threshold voltage generation unit which generates a first threshold voltage lower than substantially half of a peak voltage of the voltage signal; a second threshold voltage generation unit generating a second threshold voltage lower by the first threshold voltage than the peak voltage of the voltage signal; and a selection unit which, when the voltage signal changes from a first potential to a second potential higher than the first potential, selects and outputs the second threshold voltage after exceeding the first threshold voltage, and when the voltage signal changes from the second potential to the first potential, selects and outputs the first threshold voltage after falling below the second threshold voltage.

Receiving apparatus and method thereof

According to one aspect of this invention, there is provided a transmitting and receiving device including a transmitting device having a pulse width modulation encoder which generates a pulse width signal having a pulse width corresponding to the binary digital signals outputted from the plurality of sigma-delta analog-to-digital conversion units, and a light-emitting element drive unit which generates and transmits an optical signal by causing a light-emitting element to emit light on the basis of the pulse width signal, and a receiving device having an optical reception unit which converts a current signal, obtained by receiving the optical signal by a light-receiving element, into the pulse width signal, and a pulse width demodulation decoder which reconstructs the binary digital signals of a plurality of channels on the basis of the pulse width signal.

Transmitting and receiving device and transmitting device and receiving device

A light-emitting element driving circuit comprises a current supplier serially connected to a light-emitting element and operative to supply a current to the light-emitting element; and a switching unit operative to control switching between the states of the current supplied to the light-emitting element from the current supplier. The switching unit includes a current path consisting of a diode and a semiconductor switching element. The diode is connected in parallel with the light-emitting element and in a forward direction directed from an anode to a cathode of the light-emitting element. The semiconductor switching element is connected serially to the diode and operative to switch between the states of conductive and non-conductive based on a control signal. A voltage drop across the current path when the semiconductor switching element is made conductive is determined lower than a forward voltage of the light-emitting element when it emits light.

Light-emitting element driving circuit having a switching unit with a diode

A semiconductor photosensor device includes a plurality of photodiode sections, a switch, and an output section is provided. The plurality of photodiode sections have different illuminance-output characteristics. The switch selects any one of the plurality of photodiodes sections on the basis of an illuminance of incident light irradiated on the photodiode sections. The output section outputs an signal from the selected photodiode section through the switch.

Semiconductor photosensor device and information apparatus with sensitivity region for wide dynamic range

A semiconductor photosensor comprises: a semiconductor substrate; a first photodiode formed on the semiconductor substrate; a second photodiode formed on the semiconductor substrate; a first amplifier circuit configured to amplify photocurrent from the first photodiode, the first amplifier circuit being formed on the semiconductor substrate; a second amplifier circuit configured to amplify photocurrent from the second photodiode, the second amplifier circuit being formed on the semiconductor substrate and having an amplifying characteristic substantially identical to that of the first photodiode; an infrared transmissive filter configured to attenuate visible light components relative to infrared light components in incident light, the infrared transmissive filter being provided on the second photodiode; and a subtraction circuit configured to output a difference between an output of the first amplifier circuit and an output of the second amplifier circuit, the subtraction circuit being formed on the semiconductor substrate.

Semiconductor photosensor

A semiconductor photosensor device which outputs a detection result when a trigger signal is inputted, comprises: a photodiode current arithmetic circuit which is in an operating state regardless of whether before or after the input of the trigger signal, and which outputs a photocurrent generated by light irradiation; a first amplifier which is in an operating state regardless of whether before or after the input of the trigger signal, and which amplifier and outputs the output of the photodiode current arithmetic circuit; and a second amplifier which is in a non-operating state before the input of the trigger signal, wherein the second amplifier shifts to an operating state upon receiving the trigger signal, and amplifies and outputs the output of the first amplifier.

Photosensor device and portable terminal unit having semiconductor photosensor device

An optical signal receiving circuit disclosed herein comprises: a first transimpedance amplifier configured to convert a first current signal into a first voltage signal, wherein the first current signal is generated in a first photodiode, to which an optical signal is inputted; a reference voltage generating circuit configured to generate a second voltage signal which is independent of the first voltage signal and which is a signal of a reference voltage; a level shift circuit configured to shift at least one of the first voltage signal and the second voltage signal in a close direction and output it, wherein the close direction is a direction in which the center voltage of the amplitude of the first voltage signal and the voltage of the second voltage signal get closer; and a differential amplifier which amplifies a difference between the first voltage signal and the second voltage signal.

Optical signal receiving circuit and optical signal receiving semiconductor device

A photo-detecting semiconductor device according to an embodiment of the present invention has a first photodetector element and a second photodetector element placed adjacent to each other and isolated from each other to each generate an electric signal responsive to a received optical signal; a signal detecting circuit which amplifies the electric signal from said first photodetector element and outputs a detection-use electric signal to detect a predetermined optical signal received at said first photodetector element; a power supply circuit which starts the supply of power upon receiving said detection-use electric signal from said signal detecting circuit; and a signal output circuit supplied with power from said power supply circuit to amplify the electric signal from said second photodetector element and output an output-use electric signal. An electrical circuit has the photo-detecting semiconductor device.

Photo-detecting semiconductor device and an apparatus having such a photo-detecting semiconductor device

A semiconductor position sensitive detector has an epitaxial layer of a second conductivity type formed on a semiconductor substrate of a first conductivity type. A first diffusion layer of the first conductivity type is formed in said epitaxial layer so as to isolate a rectangular portion of this epitaxial layer from the rest. A second diffusion layer of the first conductivity type is further formed in said rectangular portion of the epitaxial layer, in order to increase the resistance value of the epitaxial layer. In addition, due to the formation of the second diffusion layer, two p-n junctions having photoelectric transfer ability are formed in this device. So, a semiconductor position sensitive detector having excellent photoelectric characteristics can be obtained.

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Kawasaki, Japan

Hiroshi Suzunaga