Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Tsuyoshi Maro

Osamu Ishizaki

Hideo Daimon

Tatsuo Araki

Toshinori Sugiyama

Hideo Fujiwara

Masafumi Yoshihiro

Satoru Ohnuki

Osamu Kitakami

Hiroyuki Hirata

Katsusuke Shimazaki

Yoshiaki Minakawa

Takeshi Ohnuki

Makoto Aihara

Yasuhiko Kokufuda

Kenji Ohta

Takashi Sugiyama

Hiroyuki Awano

Hikaru Mizutani

Kunio Wakai

Akito Sakemoto

Reiji Tamura

Hiroyoshi Takagi

Masaki Yamazaki

Naoki Kitagaki

Susumu Aoki

Katsuhiro Takahashi

Kazuyoshi Adachi

Susumu Shibasaki

Akihiko Soya

Yuuji Yamazaki

Hiroyuki Ohta

An imaging module for biometrics authentication comprises: a light source irradiating a living body with light capable of passing through the living body; a prism having an incidence surface including an incidence area for taking in light emerging from the living body, two or more reflecting surfaces for reflecting the light taken in through the incidence area, and an outlet surface for outputting the light reflected by the reflecting surfaces; and a camera module including a lens for focusing the light emerging from the outlet surface of the prism and an image pickup device for converting the light focused thereon by the lens into an electric signal and outputting the electric signal.

Imaging module for biometrics authentication, biometrics authentication apparatus and prism

A camera module includes a mount for holding a lens directly or indirectly, a cover plate glass with transparency fixed to the mount. A solid-state imaging device is mounted on the cover plate glass. The cover plate contacts a plurality of ribs formed in the mount, and the mount and the cover plate are positioned.

Camera module

For use in combining and/or splitting a 3-wavelength multiplexed light, in which if central wavelengths of the three bands are denoted as &#x3bb;1, &#x3bb;2 and &#x3bb;3, in a relation that 0.92&#x2266;&#x3bb;2/&#x3bb;1&#x2266;1.08, 0.20&#x2266;&#x3bb;3/&#x3bb;1&#x2266;0.92 or 1.08&#x2266;&#x3bb;3/&#x3bb;1&#x2266;5.00, the wavelength multiplexing and demultiplexing device comprises two optical filters of different characteristics, supported by one of more optical substrates combined in a single package, wherein, when a 3-wavelength multiplexed light is led to a first filter A for splitting the 3-wavelength multiplexed light into light of a band of &#x3bb;3 and a 2-wavelength multiplexed light of &#x3bb;1 and &#x3bb;2, and when the 2-wavelength multiplexed light is led to a second filter B for splitting the 2-wavelength multiplexed light into light of a band of &#x3bb;1 and light of a band of &#x3bb;2, an optical edge filter is used for the filter A and an optical band-pass filter is used for the filter B.

Wavelength multiplexer/demultiplexing device

The wavelength division multiplexer includes a single optical substrate or a plurality of optical substrates integrated together, on which the first optical filter and the second optical filter are placed. The center wavelengths of three wavelength bands, &#x3bb;, and &#x3bb;, satisfy: 0.92&#x2266;&#x3bb;&#x2266;1.08, and 0.20&#x2266;&#x3bb;&#x2266;0.92 or 1.08&#x2266;&#x3bb;&#x2266;5.00. The first optical filter combines or separates light of &#x3bb;and two-wavelength multiplexed light of &#x3bb;and &#x3bb;. The second optical filter combines or separates light of &#x3bb;and light of &#x3bb;

Wavelength division multiplexer

An optical diskis provided with a hubat the central portion of a substratel. A relationship Y/X&#x2267;0.015, preferably Y/X&#x2267;0.05 is satisfied where X is the projected area of the substrateand Y is a contact area between the huband the substrate. As result, no slippage occurs between the huband the substrateeven when they are rotated at high speed than conventional. With this higher rotational speed, the data transfer rate is improved, and irregular rotation and the camming are suppressed, thereby reducing tracking errors and write/read errors.

Optical disk, disk substrate, and drive

A magneto-optical recording head comprises a magnetic coil formed on a lower surface of a transparent substrate opposed to a magneto-optical disk. A heat sink layer is provided at the outside of the magnetic coil on the lower surface. An objective lens is supported on an upper surface of the transparent substrate. The heat, which is generated by the magnetic coil, is released via the heat sink layer to the space between the magneto-optical disk and the substrate. The release of the heat is facilitated by the air stream which is generated by the rotation of the magneto-optical disk. The heat can be effectively released from the magnetic coil without inhibiting optical characteristics of the objective lens.

Magneto-optical head having heat sink layer

An object of the present invention is to provide a film-surface light-incident type magneto-optical recording medium which is used by means of an objective lens having a large NA value and is excellent in productivity and yield, and a magneto-optical recording apparatus. According to the present invention, there is provided a magneto-optical recording medium for conducting recording or reading-out from the film surface side of the recording medium by traveling of a flying head incorporated with an objective lens having a numerical aperture (NA) of not more than 0.95 and not less than 0.8, wherein at least a reflective film, a recording layer, a transparent dielectric layer, a transparent resin layer and a lubricant layer are laminated on a substrate in that order.

Magneto-optical storage apparatus having the relation between numerical aperture and recording medium

A magneto-optical recording medium comprises a protective layer having a self-lubricating property formed at an uppermost layer on a side opposite to a substrate wherein a recording or reproducing light beam comes into a side of the protective layer. The thickness and the refractive index of the protective layer are selected under predetermined conditions depending on whether or not evanescent light is transmitted through the protective layer. It is possible to perform high density recording and reproduction thereof by utilizing the evanescent light. A protective layer having a self-lubricating property may be also formed on a bottom surface of an optical head opposing to the optical recording medium. Even when the optical head contacts with the surface of the optical recording medium, the sliding scratch scarcely occurs, because the optical head smoothly glides on the recording medium surface. It is possible to reduce the influence of multiple interference of light which would be otherwise caused in an air layer existing between the optical recording medium and the optical head, and it is possible to suppress variation in reproduced signal intensity.

Optical recording medium with solid protective layer having self-lubricating property

A magneto-optical recording medium comprises, on a substrate, a reflective layer, a first dielectric layer, a recording layer, and a second dielectric layer successively in this order, for being irradiated with a recording or reproducing light beam coming from a side of the second dielectric layer. A diamond-like carbon layer as a self-lubricating layer is formed on the second dielectric layer. An optical head comprises a floating type slider installed with a solid immersion lens. A protective film having a self-lubricating property may be also formed on a bottom surface of the slider opposing to the optical recording medium. Even when the floating position of the optical head is varied, and the optical head contacts with the surface of the optical recording medium, then the sliding scratch scarcely occurs, because the optical head smoothly glides on the recording medium surface. A lubricating layer may be further formed on the self-lubricating layer.

Optical recording medium, optical head, and optical recording device

A cavity surface-forming plate of a mold for injection-molding a plastic substrate is coarsely polished, and then a surface for defining a cavity is applied with electroless Ni&mdash;P plating. The surface of the plating is polished with abrasive grains to obtain surface roughness of Ra&lE;2.0 nm and Rmax&lE;22 nm. The plastic substrate molded with the mold has smoothness equivalent to the polished plating surface. A concave-convex pattern for forming pits may be formed on the cavity surface. A magnetic disk or an optical disk provided with the substrate makes it possible to realize the near contact system for a magnetic or magneto-optical head. Thus, it is possible to realize high density recording.

Substrate for information recording disk, mold and stamper for injection molding substrate, and method for making stamper, and information recording disk

A recording disk comprises a substrate including a plastic material, and an overlay arranged over the substrate and including a recording substance for recording therein an information, and a radially-outer periphery of the overlay is received within a radially-outer periphery of the substrate as seen in an axial direction of the recording disk.

Recording disk and producing method therefor

Optical recording medium, optical head and optical recording device

Optical recording medium and optical recording device

A cavity surface-forming plate of a mold for injection-molding a plastic substrate is coarsely polished, and then a surface for defining a cavity is applied with electroless Ni-P plating. The surface of the plating is polished with abrasive grains to obtain surface roughness of Ra.ltoreq.2.0 nm and Rmax.ltoreq.22 nm. The plastic substrate molded with the mold has smoothness equivalent to the polished plating surface. A concave-convex pattern for forming pits may be formed on the cavity surface. A magnetic disk or an optical disk provided with the substrate makes it possible to realize the near contact system for a magnetic or magneto-optical head. Thus, it is possible to realize high density recording.

Substrate for information recording disk, mold and stamper for injection

Growing community of inventors

Ibaraki, Japan

Tsuyoshi Maro