Sharp Kabushiki Kaisha Corporation

Other

Junji Hirokane

Akira Takahashi

Kenji Ohta

Michinobu Mieda

Hiroyuki Katayama

Junichiro Nakayama

Yoshiteru Murakami

Noboru Iwata

Tetsuya Inui

Junsaku Nakajima

Naoyasu Iketani

Kazuo Van

Go Mori

Akira Shibata

Yoshiyuki Nagahara

Toshihisa Deguchi

Hideyoshi Yamaoka

Hideaki Sato

Yukinori Nishitani

Shigeo Terashima

Tomoyuki Miyake

Junichi Washo

Shohichi Katoh

Masanori Shimo

Ippei Suzuki

An optical read/write apparatus causes a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers. In this case, the optical read/write apparatus operates so that data is read/written from/into a second data storage layer after fully recording a recordable area of a first data storage layer. Thus, light can be shone with uniform intensity across the substantially entire recordable area of the second data storage layer without using a complex read/write system even under such conditions that the transmittance to light of the first data storage layer in the recordable area may vary depending on whether any data is recorded in the recordable area.

Optical storage medium, optical read/write apparatus, and optical read/write method

An optical disk includes a plurality of disk sheets which are laminated, and each of which has a recording face on one of the surfaces and a flat back surface, wherein the plurality of disk sheets are laminated by adhesive layers in such a manner that between adjacent two disk sheets, a back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet. The foregoing structure realizes an optical disk of desirable recording/reproducing characteristics, which is flat and has a fixed interval between recording faces, and which permits the problems of coma aberration, spherical aberration, etc., to be suppressed.

Optical disk and optical disk recording and reproducing device

A method for forming micropatterns includes forming a thin film consisting of a single layer or of plural layers on a substrate, irradiating an energy beam to the thin film to elevate the temperature of a region to a predetermined temperature or higher to thereby modify the region of the thin film, and patterning the thin film at least in such a manner to leave over the modified region.

Method for forming micropatterns

Optical storage medium enabling uniform light transmittance, optical read/write apparatus for same, and optical read/write method for same

A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditionscompandcompwhere Tcompis a compensation temperature of the first magnetic layer, Tc, Tcand Tcare Curie temperatures of the first, second and third magnetic layers, respectively.

Magneto-optical recording medium having a reproducing layer composed to control movement of domain walls therein

A recording and reproducing device of the present invention is provided to achieve the object of realizing stable and desirable recording and reproducing of information by suppressing fluttering of an optical disk by way of suppressing pressure fluctuation which is caused, for example, when an objective lens or an optical pickup with the objective lens is moved. The object is attained by a transparent stabilizer, provided between a disk and an optical pickup, which is moved with the optical pickup, and a slider which is provided to face the transparent stabilizer with the disk in between. The slider is supported to oscillate, and the surface of the slider facing the disk is flat. During rotation of the disk, the slider moves to balance the air pressure between the transparent stabilizer and the disk with that between the slider and the disk.

Recording and reproducing device having a stabilizing board and vertically-oscillating slider

A disc recording element is provided with a disc substrate having a hole at its center, a circular information recording area on its surface that is concentric with the hole. A hub is fitted to the hole. The disc substrate has a relief portion thereon for position alignment of the hub.

Disc-like information recording medium, stamper, stamper configuring apparatus, disc master and hub mounting apparatus

Growing community of inventors

Nara, Japan

Junji Hirokane