Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Yuzo Shimizu

Hideo Fukuda

Masaki Taniguchi

Yasufumi Shirakawa

Tetsuo Chato

Shinya Esaki

Hiroshi Yamaguchi

Shinichi Hamaguchi

Toyoyuki Shimazaki

Kenji Imaizumi

Hiroaki Yamamoto

Daisuke Furukawa

Hisatada Yasukawa

Naoto Shimada

Takeshi Matsuda

Toshihiro Kuroda

Yousuke Kuroiwa

Toyonori Kusuhara

Yosuke Kuroiwa

Katsuichi Ohsawa

Katuichi Ohsawa

The optical pickup device according to the present invention includes: a light source which emits a first light at a first wavelength, a second light at a second wavelength and a third light at a third wavelength; an optical path combining unit which combines vectors of the first, second and third light emitted by the light source, and matches optical axes of the first light and the third light; a light collection unit which condenses the light from the optical path combining unit into the optical information storage medium; a diffraction element which diffracts reflected light from the optical information storage medium; a first photo detector, a second photo detector and a third photo detector which receives the diffracted light from the first diffraction element; and a prevention unit formed between the first diffraction element and the first photo detector, the second photo detector and the third photo detector, and which prevents irradiation of + first-order diffracted light diffracted by the first diffraction element into the first photo detector, the second photo detector, and the third photo detector.

Optical pickup device

A packaging structure suitable for an integrated circuit device receiving short-wavelength laser light is provided. A lead-mounted substrate is placed on the side of the light receiving surface of the integrated circuit device having a photo detecting part. The lead is electrically connected with the integrated circuit device via an electrode. The integrated circuit device and the substrate are encapsulated with an encapsulation section. The substrate has an opening at a position above the photo detecting part.

Integrated circuit device packaging structure and packaging method

The test circuit according to the present invention includes: a plurality of light-receiving elements; a plurality of amplifiers, each of which converts, into a voltage, a photoelectric current supplied from one of the light-receiving elements; and an electric current supplying unit which supplies an electric current to each of the light-receiving elements and each of the amplifiers. In this test circuit, the electric current supplying unit selectively supplies an electric current to a first group of light-receiving elements and to a second group of light-receiving elements, the first group of light-receiving elements including light-receiving elements, out of the plurality of light-receiving elements, which are neither vertically nor horizontally adjacent to each other, and the second group of light-receiving elements including light-receiving elements, out of the plurality of light-receiving elements, which are vertically or horizontally adjacent to the light-receiving elements of the first group of light-receiving elements.

Test circuit and test method that includes supplying a current to a plurality of light-receiving elements

There is provided a light receiving circuit capable of preventing an output variation of the light receiving circuit due to a change in ambient temperature with a simple configuration. The light receiving circuit is provided with a photodiodefor LD power monitoring and an I-V amplifierconnected with a feedback resistor, wherein a light receiving sectionof the photodiodeis covered with a protective film. Temperature dependences between a light transmittance of the protective filmin accordance-with a shift of a wavelength of a laser beam due to a change in ambient temperature, and a resistance value of the feedback resistorare set in such a way that they may be mutually compensated and an output voltage from the light receiving circuit may be constant for a temperature change.

Light receiving circuit, semiconductor laser device, and optical pickup device

An amplifier circuit according to the present invention includes: a first operational amplifier having a negative input terminal, a positive input terminal, and an output terminal; a photodiode connected to the negative input terminal; a first resistor inserted between the output terminal and the negative input terminal; and a second resistor inserted between the output terminal and the positive input terminal, in which the amplifier circuit outputs current from the output terminal via the second resistor.

Amplifier circuit and optical pickup device

Disclosed is a light receiving device for reading an optical medium compliant with any of different standards. The receiving device includes light receiving elements and an amplifier circuit. Each light receiving element is for receiving light reflected from an optical medium compliant with a different one of the standards and output a signal responsive to the received light. The amplifier circuit is for amplifying a signal derived from output of the light receiving elements. The signal amplified by the amplifier circuit is derived by subtracting an output signal of one of the light receiving elements that receives light from the optical medium from an output signal of the other light receiving elements.

Light receiving device for reading an optical medium with reducing influence of dark current and stray light performance

The present invention is intended to prevent a light-emitting diode from emitting light continuously in the case when the level at an input terminal is fixed high because of software or the like and to avoid various problems, such as battery exhaustion and breakdown of the light-emitting diode, in PDAs, cellular phones, etc. For these purposes, a high-pass filterfor passing the high-frequency components of an optical transmission input signal having a pulse waveform and a binary circuitfor binarizing the output signal of the high-pass filterso as to be returned to a pulse waveform are provided in the preceding stage of a light-emitting device driving circuitfor driving a light-emitting diodefor optical transmission.

Optical transmitter

A packaging structure suitable for an integrated circuit device receiving short-wavelength laser light is provided. The integrated circuit device having a photo detecting part, leads and wires for connection therebetween are encapsulated in an encapsulation section. A recess is formed on the light incident surface of the encapsulation section above the photo detecting part, to thin the encapsulation section on the surface of the photo detecting part and thereby reduce the energy of light absorbed by the encapsulation section.

Integrated circuit device installed structure and installation method

A semiconductor device includes the following: a semiconductor substrate of a first conduction type; an intrinsic semiconductor layer of the first conduction type formed on the semiconductor substrate; a first semiconductor layer of a second conduction type formed on the intrinsic semiconductor layer; a first impurity layer of the first conduction type formed in the first semiconductor layer of the second conduction type; and a bipolar transistor and a MIS transistor formed in the first semiconductor layer of the second conduction type. The laminated structure of the semiconductor substrate, the intrinsic semiconductor layer, and the first semiconductor layer provides a diode for photoelectric conversion. A first insulator layer and a second insulator layer are formed respectively in at least a portion below the bipolar transistor and the MIS transistor. The transistors are isolated from the semiconductor substrate by the insulator layers, so that the characteristics of the transistors can be adjusted independently of the diode.

Growing community of inventors

Osaka, Japan

Yuzo Shimizu