Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Naoya Hotta

Hidenori Wada

Daisuke Ogata

Yoshiaki Komma

Kanji Wakabayashi

Eishin Mori

Katsuhiko Yasuda

Hiroaki Yamamoto

Shin-ichi Kadowaki

Sadao Mizuno

Tetsuo Saimi

Masahiro Inata

Yoshihiro Kanda

Yoshihiro Ikawa

An optical pick-up capable of reproducing information excellently on both CD and DVD, which are significantly different in terms of three kinds of factors, a base material thickness, a wavelength of a light source, and NA, and detecting TE signals by three kinds of methods, that is, the phase difference method, the PP method, and the 3-beam method, which are necessary to record and reproduce information. The optical pick-up is formed by integrating laser light sources having two kinds of wavelengths (&#x3bb;) for detecting TE signals; photodetectors, and hologram for generating the diffracted light for detecting signals. The distance dbetween the center of the photo detecting portion PDand the light emitting spot of the first semiconductor laser light source and a distance dbetween the center of the photo detecting portion PDand the light emitting spot of the second semiconductor laser light source substantially satisfy the following relationship:&#x3bb;

Optical pick-up, optical disk apparatus and information processing apparatus

Tilt which is inclination of a normal of optical disk relative to optical axis of optical head is corrected with a liquid crystal element. In a driver for the liquid crystal element, a periodic waveform generator generates periodic waveform and an inverting element inverts the periodic waveform. The periodic waveform and the inverted waveform are connected to two ends of a potential divider which provides partial voltages. The periodic waveform is connected to a common electrode of the liquid crystal element, and the partial voltages of the potential divider are connected to electrodes opposing the common electrode. A structure of a driver circuit for each direction is simple. Tilt in a plurality of directions can be performed independently of each other. Spherical aberration is also corrected. When the liquid crystal element is mounted to a fixed component, deterioration due to jitters is reduced.

Liquid crystal driver and optical head for tilt correction

An optical element has a phase change layer for changing the phase of light passing therethrough; a plurality of aberration correcting electrodes, arranged on one side of said phase change layer, for correcting optical aberrations, each of said aberration correcting electrodes being split into a plurality of regions; an insulating film interposed between said aberration correcting electrodes; and a specific electrode arranged on the other side of said phase change layer, and wherein: said aberration correcting electrodes, at least other than the outermost aberration correcting electrode as viewed from said phase change layer, have openings formed in prescribed positions, and each of said aberration correcting electrodes, other than the innermost aberration correcting electrode, faces said phase change layer through said openings formed in other aberration correcting electrodes.

Optical element, optical head and optical recording reproducing apparatus

Growing community of inventors

Sagamihara, Japan

Naoya Hotta