Canon Kabushiki Kaisha

Other

Kazuyoshi Ishii

Koyo Hasegawa

Makoto Hiramatsu

Kozo Yoshida

Masakuni Yamamoto

Ikuo Watanabe

Koichiro Nishikawa

Kazunori Suzuki

Haruhiko Horiguchi

Seiichiro Satomura

Shinnosuke Torii

Yoshikazu Asai

Shinichi Tachibana

Katuya Yamazaki

An ionizing radiation detection apparatus of the present disclosure includes a first drift electrode disposed inside a chamber and a first detection unit disposed inside the chamber so as to oppose the first drift electrode, wherein the first detection unit is configured to detect a first ionization electron produced through Compton scattering caused by an incident &#x3b3;-ray inside the scattering gas, and a second drift electrode configured to emit a reference X-ray upon being excited by the incident &#x3b3;-ray with a second detection unit disposed so as to oppose the second drift electrode and configured to detect a second ionization electron produced as the reference X-ray is photoelectrically absorbed by the scattering gas, and a control unit configured to compensate for a change in an amplification factor of a signal output from each of the first detection unit and the second detection unit.

Ionizing radiation detection apparatus

An optical disk apparatus that includes a movable part having an objective lens for focusing a laser beam onto an optical disk. A lens-holding member holds the objective lens. A protecting member prevents contact of the objective lens with the optical disk. An elastic supporting member supports the movable part, and an actuator drives the movable part toward or apart from the optical disk. The apparatus is constructed not to cause contact of the protecting member with the optical disk in a non-working state of the actuator, even when the elastic supporting member is bent by gravity toward the optical disk.

Optical disc apparatus employing an objective lens having a high numerical aperture

An optical pickup includes an objective lens, a protection member for protecting the objective lens, and a lens holding member configured to hold these members. The optical pickup records and/or reproduces an information signal on and/or from an optical recording medium by condensing laser light through the objective lens. The protection member includes a bearing surface to contact a surface of an edge portion of the objective lens not facing the optical recording medium, an aperture to control a diameter of laser light to be incident on the objective lens, and a protection portion protruding toward the optical recording medium with respect to the objective lens. The bearing surface, the aperture, and the protection portion are integrally formed with one another.

Optical pickup and optical disk drive apparatus

An optical disk device for driving an optical disk having a rotation center and a recording track around the rotation center. The device includes a light source which emits a light beam, an objective lens which irradiates a position on the recording track of the optical disk with the light beam from the light source, and a lens holding member which holds the objective lens. The lens holding member has a plurality of fitting sections. A plurality of elastic supporting members each has a longitudinal length and is fitted at one end thereof to one of the fitting sections of the lens holding member, and a supporting unit base has a plurality of anchor sections supporting the other end of each of the elastic supporting members. The plurality of anchor sections are arranged on first and second sides with reference to a tangent line hypothetically drawn tangentially to the recording track at the position irradiated with the light beam via the objective lens, the rotation center of the optical disk being located on the second side. Each of the anchor sections that are arranged on the first side are arranged closer to the objective lens in the extending direction of the tangent line than are the anchor sections arranged on the second side.

Optical pickup and optical disk device

A process for recording information on and reproducing information from a reflection-type holographic information recording medium, having a reflecting layer. Recording includes (i) branching a light beam from a light source into a first branched light beam and a second branched light beam, (ii) forming an information light beam from the first branched light beam by modulation with a spatial light modulation element, and (iii) recording the information by forming an interference fringe by projecting the second branched light beam as a recording reference light beam together with the information light beam onto the recording medium. Reproducing includes projecting a light beam from the light source as a reproducing reference light beam onto the interference fringe. An angle of incidence of the recording reference light beam and an angle of incidence of the reproducing reference light beam into the interference fringe are one hundred eighty degrees from one another.

Holographic information recording-reproducing process and apparatus therefor

An optical disk apparatus includes a movable part having an objective lens for focusing a laser beam onto an optical disk. A lens-holding member holds the objective lens. A protecting member prevents contact of the objective lens with the optical disk. The protecting member is spaced apart from the optical disk. An elastic supporting member supports the movable part, and an actuator drives the movable part toward or away from the optical disk. The apparatus is constructed so as to maintain the protecting member spaced apart from the optical disk, even when the elastic supporting member is bent by gravity toward the optical disk.

Optical disk apparatus employing an objective lens having a high numerical aperture

An optical pick-up including an objective lens for collecting/irradiating laser light onto an optical disk, and an objective lens holding member for holding the objective lens. A plurality of cutout portions for injecting therein an adhesive for fixing the objective lens are provided on a side of the objective lens holding member opposite to a side thereof facing the optical disk and at the cut out portions. An adhesive is filled in a gap between a surface of the edge of the objective lens perpendicular to the optical disk and a portion of the objective lens holding member opposing the surface. A projection member is disposed on a surface of the edge opposing the optical disk and on a side of the gap opposing the optical disk.

Optical pick-up and optical disk device

A protection member for preventing the contact of an objective lens with an optical disk is a thin plate member composed of an elastic material softer than a cover layer of the optical disk and has a plurality of convex-shaped parts formed on a surface thereof, which is opposed to the optical disk, so as to surround the objective lens.

Optical disk apparatus with protection member for objective lens

A suspension supporting a magnetic head is formed by a member different in material from gimbals. As a result, the characteristic of the gimbals minimizing electric power loss in supplying current while sufficiently elastically holding the magnetic head can be compatible with the characteristic of suspension suppressing variation and impact from the outside or rotational displacement although both characteristics are different from each other. This allows the displacement of the magnetic head caused by the vibration and the impact from the outside or the horizontal displacement associated with the vertical displacement of a recording medium to be decreased, so that inductance of the magnetic head can be decreased and recording speed can be improved.

Magneto-optical head support structures

The magneto-optical recording apparatus of the present invention comprises: a magnetic head of which one end is fixed and of which the other end is free and provided with a magnetic field generating portion for applying a magnetic field onto a magneto-optical recording medium; an optical pickup, provided opposite the magnetic head with the recording medium between them, for irradiating a portion applied with a magnetic field from the magnetic head with a light beam; and a member for regulating displacement of the magnetic head in a direction parallel to a magneto-optical recording medium surface.

Magneto-optical recording apparatus having a magnetic head with a regulating member

A method for manufacturing a magnetic domain wall displacement type magneto-optical medium includes forming a magnetic layer on a substrate and forming sectioning regions in which perpendicular magnetic anisotropy of the magnetic layer is reduced, and a plurality of belt-shaped recording tracks are sandwiched by the sectioning regions and are magnetically separated from each other by irradiating the magnetic layer on the substrate with a light beam or a charged particle beam of a wavelength of not more than 550 nm and scanning the light on the substrate in parallel and at a same interval and a magnetic domain wall displacement type magneto-optical medium.

Magnetic domain wall displacement type magneto-optical medium and method for manufacturing the same

To provide an information recording method, an information recording apparatus and an information reproducing method and an apparatus for a domain wall mobile type magneto-optical medium. In the information recording method, a light beam scans on the medium for heating and at the same time a magnetic field modulated corresponding to the information is applied to a heated point, and a recording magnetic domain having an arc shaped magnetic domain wall bending convex in a forward direction of an operation of the light beam is formed so that the information is recorded. The information recording apparatus, includes an optical head to radiate the light beam for executing the information, a magnetic head to generate a magnetic field modulated corresponding to the information, and a unit for causing the optical head, the magnetic head and the medium to relatively move.

Method and apparatus for recording magnetic domain having an arc shape convex in a forward scanning direction of a magneto-optical recording medium

High speed magnetic coil for magneto-optical head

In a flat magnetic head coil constituted by spiral coil patterns made of a conductive material film and two terminals connected to the coil patterns, the coil patterns have a substantially rectangular sectional shape. A minimum pitch P &lsqb;&mgr;m&rsqb; of the coil pattern, a width W &lsqb;&mgr;m&rsqb; of the sectional shape at the minimum pitch P, and a height H &lsqb;&mgr;m&rsqb; satisfy 15 &lsqb;&mgr;m&rsqb;&lE;P&lE;70 &lsqb;&mgr;m&rsqb; and 1.8&minus;0.012P&lE;H/W&lE;7.5&minus;0.06P. When an impedance Z between the two terminals of the coil while a core made of a magnetic material is not attached is equivalently constituted by an inductance L an RF resistance Rp parallel to the inductance L and a DC resistance Rs which is series-connected to the inductance L and is independent of a frequency, the inductance L &lsqb;&mgr;H&rsqb; at 10 MHz satisfies L &lE;0.85 &lsqb;&mgr;H&rsqb;.

To provide a magnetic head drive circuit or a magneto-optical recording device used with the circuit including a pair of auxiliary coils and a magnetic field generating coil for generating a magnetic field by alternately receiving electric currents flowing in opposite directions through the pair of auxiliary coils, and recording an information signal. When the recording of an information signal is stopped, a current for recording an information signal is maintained in a flowing state and gradually reduced, thereby shifting the recording toward a stop state. Thus, the voltage generated in the auxiliary coil by electromagnetic induction when the recording is stopped is reduced, the consumption of electric power is reduced, and the recording speed is improved.

Magnetic head drive circuit including paired auxiliary coils, paired switching elements, and switch element control circuit, and magneto-optical recording device using the same

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Tokyo, Japan

Kazuyoshi Ishii