Pioneer Corporation

Nikkiso Company Limited

Pioneer Electronic Corporation

Air Water Biodesign Inc.

Mitsuru Sato

Kiyoshi Tateishi

Takanori Maeda

Ikuya Kikuchi

Kazuo Takahashi

Yoshitsugu Araki

Tomoya Murakami

Akari Agata

Wataru Onodera

Genki Adachi

Junichi Furukawa

Masayuki Iwasaki

Takayuki Nomoto

Atsuya Ito

Hiroshi Nishiwaki

Ichiro Sugai

Tadashi Kondo

An optical measurement device is provided with: a light source that irradiates, with light, a measurement object which has a fluid flowing thereinside; a light receiving unit which, upon receipt of scattered light from the measurement object irradiated with light, outputs a light reception signal according to the intensity of the scattered light; a disturbance generation unit which generates a disturbance signal for causing oscillation of a drive current to be supplied to the light source; and an adjustment unit which adjust the drive current on the basis of the result of a comparison between the disturbance signal and a signal generated on the basis of the light reception signal.

Optical measurement apparatus, optical measurement method, computer program, and recording medium

These measurement devices are each provided with: irradiation unit that irradiate a fluid with light; a light-receiving unit that receives light scattered by the fluid; an acquiring unit that acquires fluid information which indicates the flow rate or the flow velocity of the fluid; and a control unit that controls the irradiation unit on the basis of the fluid information.

Measuring apparatus

An optical pickup is provided for preventing an objective lens from colliding with an optical recording medium at the stage of initial adjustments. The optical pickup device comprises a servo circuit, and a lens driver for driving an objective lens. In the servo circuit, a drive signal generator supplies the lens driver with one of a first focus drive signal for moving the objective lens in a direction closer to an information recording layer, and a second focus drive signal for moving the objective lens in a direction away from the information recording layer. A controller in a timing generator switches a signal supplied to the lens driver from the first focus drive signal to the second focus drive signal when the level changes by a predetermined range or more in a servo signal which is generated during a period in which the first focus drive signal is being supplied to the lens driver.

Optical pickup device and apparatus for reading data from optical storage medium

The depth of pits is determined by a trade-off between the level of a push-pull signal used for servo application by a push-pull method and the level of an RF signal as a reproduced signal of information. The depth d is set to be the optimum for a disk system, which has a refractive index n of a medium, an optical wavelength &#x3bb;, and an optical system with a NA (Numerical Aperture) of 0.75. The most suitable depth d for both the push-pull signal level and the RF signal level falls within a range of &#x3bb;/5.5n&#x2266;d&#x2266;&#x3bb;/4.7n, the second most suitable depth d falls with a range of &#x3bb;/5.5n&#x2266;d&#x2266;&#x3bb;/4.5n, and the depth d as the widest standard falls within a range of &#x3bb;/8n&#x2266;d&#x2266;&#x3bb;/4.5n.

Information recording medium, information reproducing apparatus, information recording apparatus, and information recording/reproducing apparatus

An optical disc player executes a focus pull-in operation while avoiding an inconvenience that an objective lens comes into contact with an optical disc, or the like. The objective lens is forcedly moved gradually from a position that is away from the surface of the optical disc and outside a capture range of a focus servo toward the surface of the optical disc. When the objective lens reaches the capture range of the focusing servo loop by the moving operation and a distance between the objective lens and the disc surface is at the minimum distance or is changing in a widening direction, the moving operation of the objective lens is stopped.

Optical disc player with focus pull-in function

A tracking servo apparatus in which reflection light obtained when a laser beam is irradiated onto a recording surface of an optical disc is photoelectrically converted, thereby obtaining a photoelectric conversion signal, a tracking error signal showing a deviation amount of an irradiating position of said laser beam for a track in a disc radial direction on the recording surface is generated by the photoelectric conversion signal, a spherical aberration occurring in an optical system is detected, a level of the tracking error signal is corrected on the basis of the detection result, and the irradiating position of the laser beam is moved in the disc radial direction in accordance with the level-corrected tracking error signal.

Tracking servo apparatus of optical information recording and reproducing apparatus

A phase device for providing a phase difference between an inner radius portion and an outer radius portion of a light beam which is emitted from a light source is provided in an optical path between the light source of an optical pickup apparatus and an objective lens. The light beam to which the phase difference has been provided is converged by the objective lens and irradiated to an optical disc. An interference of an inner radius portion and an outer radius portion of the returning light beam caused when the light beam is diffracted by the optical disc with &#xb1;1 primary diffracted light caused by the diffraction is suppressed. Therefore, an intensity fluctuation of the returning light beam caused by the interference is suppressed. A spherical aberration error showing a thickness error of the optical disc and a focusing error having a high linearity can be detected with high precision on the basis of the returning light. A numerical aperture of the objective lens, consequently, can be increased, high density information recording and information reproduction can be performed, and further, an optical pickup apparatus and an information recording and/or reproducing apparatus each having compatibility are realized.

Optical pickup apparatus and information recording and/or reproducing apparatus

A variable optical unit is provided with at least two phase-shift regions for providing light with phase differences. Phase-shift amount of the phase-shift region is adjusted by the applied voltage in accordance with birefringence of an information medium. A light beam emitted from a light source is incident on the variable optical unit through a collimator lens and a beam splitter. The light beam is polarized in accordance with the aforementioned phase-shift amount of the variable optical unit and converged by an objective lens to radiate the information medium. The reflected light polarized due to the effect of the birefringence of the information medium is polarized again according to the phase-shift amount of the variable optical unit. The reflected light is thereby polarized in the direction in which the beam splitter can reflect the reflected light and then the reflected light reflected by the beam splitter is detected by the condenser lens and an optical detector.

Optical pickup and information recording and/or reproducing apparatus including the same

A power controller is provided which can control the emission power from a light source to follow an appropriate response property based on a target value. The power controller includes feedforward systems for allowing currents corresponding to target values set at target value setting units to be switched at a switching device and supplied as a power setting current to an adder. Also included are feedback systems for detecting the power of the laser beam emitted by a semiconductor laser serving as the light source and adjusting a feedback current to stabilize the deviation from the target values at a predetermined value. Further included are a switching device for allowing the target values to be switched and supplied to the aforementioned feedback systems, and the adder for adding a feedback current and the power setting current to thereby generate a drive current for driving the semiconductor laser. The switching devices are simultaneously switched upon changing the power of the laser beam in response to the target values, thereby implementing an appropriate response property allowing no ringing caused in the power upon the transient event.

Power controller

An optical information recording and reproducing apparatus capable of recording and reproducing information data accurately with respect to an optical recording medium. The optical information recording and reproducing apparatus includes an aberration correction part which corrects aberration of the optical system. The apparatus determines whether or not an aberration correction by the aberration correction part is completed based on the signal level read from the optical recording medium, while changing a spherical aberration correction amount of the aberration correction part. The apparatus commences a recording operation or a reproducing operation of the optical information recording and reproducing apparatus if it is determined that the aberration correction was completed.

Optical information recording and reproducing apparatus

In an optical pickup direction detection unit, a detector group receives return light from an optical disc and outputs a light detection electric signal, a push-pull signal generator generates a push-pull signal, and a land prepit signal generator generates a land prepit signal. Further, a direction determiner detects a direction detection signal based on a tracking error signal and the land prepit signal.

Optical pickup direction detection unit and optical pickup direction detection method

A pickup drive apparatus for recording or reproducing with respect to a recording medium such as a CD and a DVD. In the apparatus, return light produced by irradiating an optical spot is detected by a photodetector, and a push-pull signal is produced from this detection output. A tracking error signal is produced from the push-pull signal by a low-pass filter and a phase compensating circuit. A quasi-ON/OFF control signal having information of an irradiation position of the optical spot is produced from the push-pull signal by a high-pass filter, a comparator, and a single pulse generator. When the quasi-ON/OFF control signal is produced which indicates that the optical spot is positioned on a groove, the tracking error signal is outputted via switching circuits in synchronism with this signal production. A pickup is servo-controlled based on this output signal.

Pickup drive apparatus, pickup drive method, and recording/reproducing apparatus

An optical recording apparatus for writing information on an optical recording medium in which a recording surface is covered with a transparent layer. The information to be written on the optical recording medium is converted into a pulse signal, and spherical aberration occurring due to an error of a thickness of the transparent layer is detected, the pulse signal being controlled in accordance with the detected spherical aberration.

Optical recording apparatus

An optical information recording and reproducing apparatus is provided that is capable of preventing recorded data from being deleted by mistake under a recording operation mode, and, under a reproduction operation mode, is capable of highly accurately reproducing and reading information data in which crosstalk has been removed. Under the reproduction operation mode, a single laser beam is divided into a plurality of divided laser beams, and they are individually irradiated onto a recording medium. On the other hand, under the recording operation mode, the quantity of light of each divided laser beam other than one beam of all the divided beams is reduced lower than that of the one beam, and they are all irradiated onto the recording medium.

Disclosed is a disc player for obtaining a read signal from an optical disc having sectors including land and groove tracks and ID regions, preformatted at given angular spatial intervals, which demarcate the sectors and are segmented, in the track extending direction, into two regions, each segmented region including a plural number of recording regions and non-recording regions, which are alternately and radially arrayed while being radially shifted by approximately half a track pitch from the tracks of the sectors adjacent to the segmented regions, each recording region containing record position information recorded therein having predetermined time durations. The disc player comprises: optical read means for projecting a light beam onto the optical disc and receiving a light beam reflected from a recording surface of the optical disc; first and second signal generating means for generating first and second signals which are dependent on the record position information recorded in the recording regions of the first and second segmented regions by use of a signal output from the optical read means; and ID region detecting means for outputting a detecting signal indicating that the ID region is detected when the first and second signals are both present.

Growing community of inventors

Tsurugashima, Japan

Mitsuru Sato