Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Toshihiro Koga

Shigeki Takeuchi

Shogo Horinouchi

Hideki Yoshinaka

Hidehiro Kugisaki

Jiro Mimasa

Kazuhiko Higo

Masaharu Fukakusa

Takashi Haruguchi

Kazuhisa Ide

Shuichi Nagai

Makoto Okazaki

Kazuyuki Nakashima

Fuminobu Furukawa

Sumio Tate

Takuma Katayama

Tatsuya Hiwatashi

Seiji Manabe

Masaomi Inoue

Junya Aso

Masaru Shiraishi

Mikio Tomisaki

Kouichi Bairin

Kiyoshi Hibino

Kouichi Kumamaru

Masahiro Shiihara

Syogo Horinouchi

Fumiaki Beppu

Provided is an encoder capable of achieving high position resolution without being finely divided, and capable of detecting a rotation angle or the like with high sensitivity. The encoder includes: rotary plate having a plurality of reflection structures repeatedly formed and code including light reflector; irradiator that irradiates the plurality of reflection structures with light; and light receiver that receives light reflected by the plurality of reflection structures. Each of the plurality of reflection structures has a surface in a convex shape, and each of the plurality of reflection structures has a width that is an integral multiple of a width of light reflector.

Encoder

There is provided a distance measurement device that can appropriately detect a distance to an object regardless of the distance. The distance measurement device includes a laser light source, a photodetector, and a controller. The controller performs a long-distance routine that detects timing for receiving light when an object is at a long distance, and a short-distance routine that detects the timing for receiving light when the object is at a short distance, based on a detection signal output from the photodetector during one distance measurement operation. The controller then selects one of a detection result of the timing for receiving light by the long-distance routine and a detection result of the timing for receiving light by the short-distance routine, and calculates the distance to the object irradiated with projection light based on the selected detection result.

Distance measurement device

There is provided a distance measurement device that can successfully take in reflected light from a distance measurement area, and at the same time, can achieve compactness of the distance measurement device. The distance measurement device includes a fixed part, a rotating part that is rotatably disposed on the fixed part, a laser light source that is disposed in the fixed part, and a photodetector that is disposed in the fixed part. The distance measurement device further includes a beam splitter that is disposed in the fixed part and separates an optical path of projection light emitted from the laser light source from an optical path of reflected light reflected by a distance measurement area and an imaging lens that is disposed in a common optical path of projection light and reflected light and is used for taking in reflected light reflected by the distance measurement area.

A small-sized, inexpensive optical pickup apparatus can be assembled with high accuracy. The optical pickup apparatus has a various-purpose semiconductor laser, an integrated optical assembly for guiding outgoing light to an optical disk and for separating reflected light, a light receiver for receiving light and converting the received light into an electrical signal, and a coupling member for retaining a positional relationship among the various-purpose semiconductor laser, the integrated optical assembly, and the light receiver. By using a various-purpose semiconductor laser, the optical pickup apparatus can be made in a small size at low cost, and can be accurately assembled. The apparatus is also capable of accurately and efficiently detecting the optical power of the various-purpose semiconductor laser.

Optical pickup apparatus

A wireless telephone equipment is provided with a microphone for receiving voice of a user and changing the voice to audio signals of an outgoing call, a cellular transmitter for modulating a carrier with the audio signals in a cellular communication, a cellular band-pass filter for filtering the carrier modulated in the cellular transmitter, a cordless transmitter for modulating a carrier with the audio signals in a cordless communication, a cordless band-pass filter for filtering the carrier modulated in the cordless transmitter, an antenna for transmitting the carrier filtered in the cellular or cordless band-pass filter and receiving a modulated signal, a band-pass filter for filtering the modulated signal, a cellular-cordless receiver for demodulating the modulated signal filtered to reproduce audio signals of an incoming call in the cellular communication and cordless communication, and a speaker for receiving the audio signals of the incoming call and giving voice. In cases where the equipment is positioned within call range of a cordless base station, the cordless communication is performed.

Wireless telephone equipment operating as a cordless and cellular

In an optical pickup, light, emitted from a light-emitting element, is transmitted through a first beam splitter film with polarization selectivity, and a zero-order diffraction beam and two (.+-.) first order diffraction beams are produced. These beams are applied in a condensed manner to an optical disk through a condensing element, and the return light beam from the optical disk is fed to a photodetector through a second beam splitter film with polarization selectivity, thereby effecting the recording and reproduction of information, the tracking and the focusing. A diffusion angle conversion hologram is provided between the light-emitting element and the first beam splitter film, and with respect to the diffusion angle conversion hologram, the relation between the diffusion angle of the incident beam and the diffusion angle of the outgoing beam is specified. With this arrangement, the light to be incident on the condensing element can have an ideal spherical wave free from a wave aberration, so that an image spot on the optical disk can be condensed into a diffraction limit, and besides by correcting the phase of the beam, a RF signal with a high C/N ratio, a stable focus error signal and a stable track signal are detected.

Method of manufacturing integrated optical pick-up

Optical pickup with conversion of diffusion angle of outgoing light

In an optical pickup, an optical guide member is provided in an optical path of light from a light source, and has a plurality of inclined surfaces inclined with respect to a light beam emitted from the light source. A light-receiving element is provided for receiving light and for converting the received light into an electrical signal. The optical guide member and the light-receiving element are contained in a packaging member. The light beam from the light source is reflected by the plurality of inclined surfaces of the optical guide member, and then are directed to a recording medium. The reflected light from the recording medium is directed to the light-receiving element. At least one of dry air and inert gas such as nitrogen gas is charged in the interior of the packaging member at a pressure of 0.5 atm to 1.5 atm, thereby preventing the optical characteristics from being degraded.

Integrated type optical pickup having packaging with gas-tight seal

A light source beam is incident on an optical guide block and converted in its diffusion angle by a diffusion angle conversion film on a second inclined portion of the optical guide block, and reflected by a reflecting film on a first inclined portion. Then, the light is incident on a first beam splitter film on the second inclined portion and split into transmitted light and reflected light. The reflected light is focused an optical disk light reflected from the disc passes through the first beam splitter film, and then is transmitted and reflected by a second beam splitter film on a third inclined portion. This transmitted light is incident on a polarization plane conversion plate between the third inclined portion and a fourth inclined portion, so that P and S polarization components and are transmitted through and reflected by its polarized light splitting portion, respectively. The S polarization component is reflected by its reflecting surface toward light-receiving elements. The reflected light from the second beam splitter film is reflected by a focus error detection element on the second inclined portion, and an incident light-splitting point of the polarized light splitting portion is located between the center of the optical guide block and the light-receiving elements, thereby reducing a light amount loss and also increasing a Kerr rotation angle so that an RF reproduction signal with a high C/N ratio can be obtained.

Optical pickup incorporating an integrated optical guide member

Growing community of inventors

Kurume, Japan

Toshihiro Koga