Sanyo Electric Co., Ltd.

Sanyo Optec Design Co., Ltd.

Tokyo Optec Design Co., Ltd.

Yasuyuki Kano

Yoichi Tsuchiya

Shuichi Ichiura

Osamu Ota

Hitoshi Terasaki

Seizo Kato

Toshio Ito

Yoshimoto Yamaguchi

Kenji Nagatomi

Kenji Asano

Shigeki Hori

A lens fixing device includes a lens holder having a lens (lens area) made of a resin, and a mounting portion. The lens holder has two projections. Each of the two projections is formed with a guide surface and a mounted surface. A line of intersection of an extension of the guide surface of the projections and an extension of the mounted surface of the projections in a plane direction is aligned with an optical axis of the lens area. The lens holder is positioned with respect to a plane direction orthogonal to the optical axis by contact of the guide surfaces with receiving surfaces of the mounting portion. The lens holder is fixedly attached by an adhesive.

Lens fixing device and optical pickup device

A half-wave plate is attached to a lens holder to integrally drive a collimator lens and the half-wave plate. When the lens holder is moved to a servo position, the half-wave plate is inserted in and retracted from an optical path of a laser beam. Therefore, the laser beam is formed in S-polarized light or P-polarized light with respect to a polarization beam splitter, and the laser beam is guided to a first objective lens or a second objective lens.

Optical pickup device and optical disk apparatus

A half-wave plate is attached to a lens holder holding a collimator lens, and a servo operation to the collimator lens and insertion and retraction of the half-wave plate in and from an optical path of a laser beam are performed by a common actuator. When the lens holder is moved to a servo position, the half-wave plate is inserted in and retracted from the optical path of the laser beam. Therefore, the laser beam is formed in S-polarized light or P-polarized light with respect to a polarization beam splitter, and the laser beam is guided to a first objective lens or a second objective lens.

An optical disc player for reproducing an optical disc having a pit width of 0.2-0.35 .mu.m, a pit depth of 100-120 nm, and a track pitch of 0.7-0.85 .mu.m. The optical disc player includes a semiconductor laser having a wavelength of 590-670 .mu.m and a laser beam projector which projects the laser beam from the laser onto the optical disc with a spot of a predetermined diameter.

High density optical disc player

A high density optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotated at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6. Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.

High density optical disc and optical disc player

An optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotate at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6. Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.

An optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotated at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6, Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.

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Hashima, Japan

Yasuyuki Kano