Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Funai Electric Company Ltd.

Kenya Nakai

Nobuo Takeshita

Masayuki Omaki

Masahisa Shinoda

Hironori Nakahara

Daisuke Matsubara

Noritaka Tanabe

Nozomi Enoki

Masayuki Ohmaki

A particle detection device includes: a first light source to emit first irradiation light; a first light-collection member; a second light-collection member facing the first reflection surface; a second light source to emit second irradiation light; and a first light-reception element. When the first light source emits the first irradiation light, the first light-reception element detects, as the first incident light, scattered light generated when a particle existing at a detection position in a target space is irradiated with the first irradiation light. When the second light source emits the second irradiation light, the first light-reception element detects, as the first incident light, a light ray of the second irradiation light that is reflected by the first reflection surface and a light ray of the second irradiation light that is reflected by both the first reflection surface and the second reflection surface.

Particle detection device

A light detection device includes a diffraction element and a light detection element. The diffraction element diffracts a beam of light that is incident on the diffraction element. The light detection element includes light receivers to receive diffracted light. The diffraction element generates beams of the diffracted light by dividing the beam of light. The light detection element determines a displacement of the beam of light relative to the diffraction element on the basis of quantities of light of the beams of the diffracted light. The light detection element determines an angle change of the beam of light relative to the diffraction element by dividing the quantity of light of one of the beams of the diffracted light.

Light detection device

A micro object detection apparatus () includes an optical system (). The first optical system () includes a first reflection region (), a second reflection region (), and a light reception element (). The first reflection region () has an ellipsoidal shape, and reflects scattered light scattered when irradiation light hits a particle (R) to direct the scattered light to the light reception element (), by utilizing two focal point positions of the ellipsoidal shape. The second reflection region () reflects scattered light coming from the particle (R) to direct the scattered light to the first reflection region (), so that the scattered light is directed to the light reception element () by utilizing the ellipsoidal shape of the first reflection region (). The light flux diameter of the scattered light reflected by the second reflection region () is larger than the particle (R), at the position of the particle (R) at which the scattered light is generated.

Micro object detection apparatus

A micro object detection apparatus includes an optical system. The first optical system includes a first reflection region, a second reflection region, and a light reception element. The first reflection region has an ellipsoidal shape, and reflects scattered light scattered when irradiation light hits a particle to direct the scattered light to the light reception element, by utilizing two focal point positions of the ellipsoidal shape. The second reflection region reflects scattered light coming from the particle to direct the scattered light to the first reflection region, so that the scattered light is directed to the light reception element by utilizing the ellipsoidal shape of the first reflection region. The light flux diameter of the scattered light reflected by the second reflection region is larger than the particle, at the position of the particle at which the scattered light is generated.

A floating particle detection deviceis capable of accurately identifying the type of a floating particle while achieving simplification of a configuration of the device, the device includes: a laser light irradiator () that includes a laser light emitting element () and a back-monitor-use light receiving element (); a scattered light receiver () that selectively receives light of a predetermined polarization component among scattered light generated when a floating particle () is irradiated and that generates a second detection signal; and an identification processor () that identifies the type of the floating particle on the basis of a first detection signal and the second detection signal. Incident light entering the back-monitor-use light receiving element () includes: a back-monitor-use laser beam (L); and backscattered light (Lbs) travelling toward the laser light irradiator () among the scattered light (Ls).

Floating particle detection device

An image projection device includes: a light source for emitting a light beam; a mirror unit that includes a mirror for reflecting the beam and projects an image onto a surface by rotating the mirror about a rotational axis to scan the beam; and a controller for determining, according to a function representing a relationship between a shift amount, an emitting time of the beam, a position on the surface irradiated by the beam emitted at the emitting time, and a shift angle of the mirror from its position when it is not driven, the emitting time corresponding to a target position. The shift amount is a shift amount of a position of the beam incident on the mirror or a shift amount of a position of the source relative to an optical axis of light incident on the mirror without the shift amount and perpendicularly intersecting the rotational axis.

Image protection device and adjustment method

An optical information recording medium has: a recording layer; a super-resolution functional layer; and a protective layer. Letting n be the refractive index of the protective layer with respect to a laser beam focused by a focusing optical system, &#x3bb;, be the wavelength of the laser beam, and dbe the depth of recording marks, when the super-resolution functional layer is irradiated by the focused laser beam, it forms a focused light spot including central light that irradiates the recording marks and peripheral light that irradiates a region outside the central light. The optical information recording medium further satisfies either the condition that the central light has a positive phase difference with respect to the peripheral light and d&#x3e;&#x3bb;/4n, or the condition that the central light has a negative phase difference with respect to the peripheral light and d&#x3c;&#x3bb;/4n.

Optical information recording medium and recording/reproducing device

An optical head device () provided with: an optical element () for transmissively diffracting a light beam emitted from a semiconductor laser (), generating a zero-order diffracted light beam and &#xb1;1-order diffracted light beams; and a photodetector () for receiving the zero-order diffracted light beam and the +1-order diffracted light beam after reflection from an optical disc (). The photodetector () includes a primary light receiving section () for receiving the zero-order diffracted light beam, and a first secondary light receiving section () disposed outward from the primary light receiving section (). The first secondary light receiving section () is positioned to detect an outer portion of the received light spot of the +1-order diffracted light beam, performs photoelectric conversion of this portion, and outputs a secondary detected signal.

Optical head device and optical disc device

An optical disc device uses an optical disc () capable of super-resolution reproduction, and includes a semiconductor laser (), a laser driving circuit () that supplies a driving current to the semiconductor laser, a light receiving element () that detects return light from the optical disc () and obtains reproduction signal of recording data of the optical disc (), and a light emission amount control means () that controls a light emission amount of the semiconductor laser () by the laser driving circuit () so as to keep a peak intensity of a focused light spot formed on an information recording layer of the optical discto be greater than or equal to a peak intensity at which a super-resolution effect is obtained. The light emission amount control means () controls a light emission amount of the semiconductor laser () by the laser driving circuit () based on a decrease rate D of a peak intensity of a focused light spot on an information recording layer of the optical disc () determined by an assumed disc tilt and a comatic aberration according to a thickness of a light transmitting layer of the optical disc (), and a lower limit value Pld_L of a light emission amount at which a predetermined reproduction performance is obtained.

Optical disc device, optical disc and testing method of optical disc

Provided is a signal processing device including: an adaptive filter; a PRML circuit for sequentially generating binarized data from a filtered reproduced waveform by sampling at sampling points in a period based on a clock signal and sequentially generating a partial response waveform which is to be the target waveform from the binarized data; a calculating unit for sequentially calculating first phase errors from a difference between the target waveform and the filtered reproduced waveform; a limiting unit for outputting second phase errors by excluding a specific phase error from the first phase errors; and a clock generating unit for generating the clock signal of a frequency corresponding to the second phase errors; wherein the specific phase error includes a phase error at a time when the partial response waveform reaches a specific level which excludes at least a level not less than a predetermined amplitude level.

Signal processing device, signal processing method, and optical disc apparatus

When using an optical disc medium that includes pit trains having their widths narrower than a diffraction limit, it is difficult to detect a tracking error signal and take a tracking-servo control while increasing pit density in a direction orthogonal to a pit-train extension direction. Information pit trains are arranged spirally or concentrically and formed in a structure in which their depths are changed periodically at a pitch radially along the optical disc medium, so that the tracking error signal can be obtained by push-pull detection of diffraction light from the structure.

Optical disc medium and optical disc device

An optical information recording medium includes at least one recording layer, a protective layer that transmits a focused laser beam, and a super-resolution functional layer that changes an optical characteristic in a local region smaller than the diffraction limit determined by the optical performance of the focusing optical system and the wavelength of the laser beam during at least the period of irradiation by the focused laser beam. The maximum thickness (K) between the light incidence surface of the protective layer and the recording layer is 0.083 mm.

Optical information recording medium and drive device

An optical head device mounted in an optical disc device. The optical head device is provided with a diffractive optical element and a photodetector. The diffractive optical element has: a primary diffraction region at a location on which the positive and negative first-order components and some of the zero-order component of a reflectively diffracted light beam are incident; and secondary diffraction regions at locations on which the rest of the zero-order component but none of the positive or negative first-order components of the reflectively diffracted light beam are incident. A main light-receiving section of the photodetector receives the zero-order component of a transmissively diffracted light beam that has passed through the primary diffraction region and the secondary diffraction regions. Secondary light-receiving sections receive the positive first-order component and/or the negative first-order component of the transmissively diffracted light beam that has passed through the secondary diffraction regions.

An optical pickup device includes a first optical system and a second optical system. The first optical system and the second optical system each include a mirror member that reflects light from a light source to change a direction of propagation of the light to a direction substantially perpendicular to the information storage surface of an optical disc. The first optical system and the second optical system are arranged such that a direction in which light from a first light source enters a first mirror member is substantially perpendicular to a direction in which light from a second light source enters a second mirror member.

Optical pickup device

A first signal is detected from the central part of a light beam returning from a super-resolution optical disc; a second signal is detected from a peripheral part in a direction corresponding to a track on the super-resolution optical disc; a gain adjustment unit is provided to adjust the amplitude of the first signal; a subtraction unit is provided to generate a third signal by subtracting, from the second signal, the first signal with the amplitude adjusted by the gain adjustment unit; and an unit is provided to generate a reproduced signal by combining the first signal and a signal obtained by delaying the third signal.

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Tokyo, Japan

Kenya Nakai