Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Yohichi Saitoh

Kazuo Momoo

Hideki Hayashi

Jun-ichi Asada

Yoshiaki Komma

Fumitomo Yamasaki

Toshiyasu Tanaka

Kenzo Ishibashi

Tomotada Kamei

Masatoshi Yajima

Yasushi Kobayashi

Hisashi Senga

Tomoaki Tojo

An optical recording and playback apparatus includes: a light source configured to emit a light beam; a tracking mirror configured to change a direction of the light beam; a collimator configured to form the light beam into a parallel light beam; an objective lens configured to collect the parallel light beam to the optical tape; a lens actuator configured to adjust a position of the objective lens in a focus direction of the optical tape and a position of the objective lens in a tracking direction of the optical tape; a polarization hologram plate configured to separate a reflected light beam of the light beam; a photodetector receiving elements configured to receive the plurality of light fluxes; and a control circuit configured to control the lens actuator and the tracking mirror. The tracking mirror is disposed near the light source, and movable in the tracking direction.

Optical recording and playback apparatus

In one embodiment, the optical read/write apparatus includes a plurality of optical pickups arranged to cross tracks of an optical storage medium and a control section. On finding the data that has been written by any of those optical pickups inaccurate or on detecting any defect at a location where data is going to be written by any of the optical pickups, the control section instructs another one of the optical pickups to write that data on a different track from a track on which the data should have been written.

Optical read/write apparatus and read apparatus

In one embodiment of the present invention, an optical pickup for writing and reading data on an optical storage medium comprises a diffractive element for diffracting a light beam to split it into multiple light beams. The diffracted light beams includes a zero-order diffracted light beam for writing data on a track of the land or the groove of the optical storage medium and non-zero-order diffracted light beams for reading the data from the track. The diffractive element has first and second diffraction gratings that have mutually different grating vector directions and pitches. The first diffraction grating forms light beam spots on the same track by the non-zero-order and zero-order diffracted light beams. The second diffraction grating forms a light beam spot to extend to both sides of said track, or forms a light beam spot on one side of said track, by the non-zero-order diffracted light beams.

Optical pickup and optical read/write drive

An exemplary optical pickup comprises: first, second and third photosensitive elements which are arranged to respectively receive a main light beam and first and second sub-light beams reflected from an optical storage medium; and fourth and fifth photosensitive elements which are arranged to receive the rest of the light that has also been emitted from a light source but has not been reflected from the optical storage medium. A signal that has been written on the optical storage medium with the main light beam for writing is read by performing an arithmetic operation on the signal output of the second or third photosensitive element and that of the fourth photosensitive element.

Optical pickup and optical read/write apparatus

In one embodiment, the optical pickup device includes: a light source that emits a light beam; a diffractive element that diffracts the light beam and generates a zero-order and &#xb1;first-order diffracted light beams; an objective lens that converges the diffracted light beams onto the same track on the storage medium; and a photodetector that receives the diffracted light beams reflected from the storage medium. If a distance from a light beam spot left by the zero-order diffracted light beam on the track to light beam spots left by the &#xb1;first-order diffracted light beams on that track is d [&#x3bc;m], the scanning linear velocity of the storage medium is v [m/s], and a time it takes for a phase-change material of the storage medium that has once been melted by the zero-order diffracted light beam to solidify is T [&#x3bc;s], vT&#x2266;d is satisfied.

Optical pickup device and optical read/write apparatus

An optical pickup includes: a light source; a first diffractive element which diffracts light polarized in a particular direction; an objective lens; a lens actuator which shifts the objective lens so that the magnitude of shift from its initial position in a tracking direction has an upper limit of 0.3 mm to 0.6 mm; a wave plate; a second diffractive element which has two diffraction regions configured to diffract light polarized in a direction that intersects with the particular direction at right angles and which splits the write beam reflected from the optical storage medium through each diffraction region into a transmitted light beam and at least one diffracted light beam; and a photodetector which detects the transmitted light beam, the diffracted light beams that have left the two diffraction regions, and the read beam reflected from the optical storage medium.

An optical head is provided with a light source for outputting laser light having a wavelength of 430 nm or less; an objective lens for collecting the laser light outputted from the light source to an optical disc having a plurality of information recording surfaces; a light receiving element for receiving laser light reflected on the optical disc; and a detecting lens for guiding the laser light reflected on the optical disc to the light receiving element. The detecting lens is formed of a resin material. The detecting lens is arranged so that a light collecting position of the laser light reflected on an information recording surface different from an information recording surface having a thinnest protection substrate, among the information recording surfaces, is outside the detecting lens, at the time of recording or reproducing information on or from the information recording surface having the thinnest protection substrate.

Optical head, optical disc device, computer, optical disc player and optical disc recorder

An optical pickup according to the present invention includes an integrated circuit element (LDD)for driving first, second, and third semiconductor lasers, and. The LDDis shaped so as to have a rectangular principal face surrounded by one side, with a plurality of input/output pins being arranged along each side. The plurality of input/output pins include a first pin group connected to a blue-violet laserwhose oscillation wavelength is the shortest, a second pin group connected to a red laser, and a third pin group connected to an infrared laser. The wiring structure of the optical pickup includes a first transmission linefor connecting the first pin group to the blue-violet laser, a second transmission linefor connecting the second pin group to the red laser, and a third transmission linefor connecting the third pin group to the infrared laser, where the first transmission lineis shorter than both the second and third transmission linesand. Of the rectangular principal face of the LDD, the side along which the first pin group is provided is orthogonal to the side along which the second pin group is provided or to the side along which the third pin group is provided.

Growing community of inventors

Kyoto, Japan

Yohichi Saitoh