Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Sony Corporation

Tdk Corporation

Yoshiaki Komma

Fumitomo Yamasaki

Hidenori Wada

Kousei Sano

Toshiyasu Tanaka

Seiji Nishino

Kanji Wakabayashi

Sadao Mizuno

Katsuhiko Hayashi

Shin-ichi Kadowaki

Hiroaki Yamamoto

Keiichi Matsuzaki

Yasumori Hino

Tetsuo Saimi

Joji Anzai

Michihiro Yamagata

Yasuhiro Tanaka

Hideki Hayashi

Masahiko Tsukuda

Makoto Kato

Daisuke Ogata

Kazuhiro Minami

Akihiro Yasuda

Eishin Mori

Shinichi Kadowaki

Osamu Kajino

Kenichiro Urairi

Akihiro Arai

Noboru Ito

Tatsuo Ito

Tomoaki Tojo

Hiroyasu Inoue

Shinichi Tanaka

Takashi Kikukawa

Koji Mishima

Jun Nakano

Shin-ichi Tanaka

Takeshi Shimamoto

Junichi Asada

Yoshikazu Hori

Manami Miyawaki

Shigeki Takagawa

Masahito Nakao

Noriaki Terahara

Naoya Hotta

Kaoru Matsuda

Takahiro Tomita

Takayuki Nagata

Hiroshi Yamamoto

Hiromichi Ishibashi

Seiji Nishiwaki

Kazuhiko Ishimaru

Ken'ichi Kasazumi

Yoshiyuki Shimizu

Mitsurou Moriya

Hideyuki Nakanishi

Hideki Nakata

Hideki Aikoh

Naoyasu Miyagawa

Hironori Tomita

Takeharu Yamamoto

Akio Yoshikawa

Keisuke Fujimoto

Masanari Mohri

Yasuhiro Gotoh

Tomotada Kamei

Akira Yoshikawa

Yasushi Kobayashi

Katsuhiko Yasuda

Yoshifumi Takasu

Yohichi Saitoh

Jouji Anzai

Tsuyoshi Nakasendo

Yasuyuki Kochi

Kouretsu Boku

Seji Nishino

Hiroshi Shiroiwa

Kuzuhiro Minami

Shin-Ichi Kadowaki

Provided is an objective lens which is used so that more information can be accumulated in a large-capacity optical disk and which has a further enhanced numerical aperture NA. The objective lens is a single lens having the numerical aperture NA and a refractive index n, and is configured so as to satisfy: NA&#x2265;0.91 and 1.61&#x2264;n&#x3c;1.72.

Objective lens, optical head device, optical information device, and optical disk system

An optical disk reproducing device includes a division element that divides a reflected light reflected and diffracted by an optical disk into a light flux in a central region and light fluxes in end regions; a photodetector that has a central light receiver that receives the light flux in the central region and at least two end light receivers that receive the light fluxes in the end regions, and outputs a light amount signal corresponding to a light amount of each of the received light fluxes; a non-linear processor that receives each of the light amount signals from the central light receiver and the end light receivers, and outputs linear signals and non-linear signals obtained by processing the light amount signals by linear and non-linear arithmetic operations; an equalization processor that receives the linear signals and the non-linear signals and outputs signals each amplified with a predetermined gain; an adder that adds the amplified signals and outputs an equalization signal; a reproduction signal processor that processes the equalization signal and outputs a reproduction signal and an equalization error signal; and a gain controller that receives the equalization error signal and controls an amplification gain of the non-linear signals.

Optical disk reproducing device

A recording device of the present disclosure includes a light source, an objective lens, a beam splitter, an optical element, a detector and an operation circuit. The optical element divides a light beam into a first main region, a second main region, a first main end region, a second main end region, a first sub-region, and a second sub-region. The operation circuit generates a main signal in which a first main end region signal is multiplied by a coefficient a and added to the first main region signal, and a second main signal in which a second main end region signal is multiplied by the coefficient &#x3b1; and added to the second main region signal.

Recording apparatus

An optical disc information device is an optical disc information device for reproducing and/or recording information with respect to an optical disc including a track in the form of a groove, and capable of recording information in a land portion and in a groove portion of the groove. The optical disc information device includes a laser light source, an objective lens, a transmittance limiting element, a dividing element, a light detector, a central amplifier, at least two end amplifiers, a gain controller, an adder, a reproduction signal processor, and a control signal processor. The transmittance limiting element includes a first central region, and at least two first end regions which interpose the first central region therebetween, and attenuates light passing through at least the first end regions out of a light flux emitted from the laser light source more strongly than light passing through the first central region.

Optical disc information device and information processing device

An RF hologram is divided in a direction perpendicular to a tangent line of an information track of an information recording surface of an optical disc, and includes a central region including an optical axis of laser light as well as a first end portion region and a second end portion region which sandwich the central region, the central region is formed by a binary diffraction grating and generates &#xb1;1 order diffracted light, the first end portion region is formed by a blazed diffraction grating and generates first +1 order diffracted light, the second end portion region is formed by a blazed diffraction grating and generates second +1 order diffracted light, and an RF light receiving element receives both the &#xb1;1 order diffracted light, the first +1 order diffracted light, and the second +1 order diffracted light.

Optical information apparatus and information processing apparatus

An objective lens element having excellent compatibility with optical discs having different base material thicknesses is provided. The objective lens element has optically functional surfaces on an incident side and an exit side. At least either one of the optically functional surfaces on the incident side and the exit side includes a diffraction portion which satisfies at least either one of the following formulas (1) and (2):&#x3b8;&#xd7;&#x3b8;&#x3c;0 ('&#xd7;' represents multiplication)&#x2003;&#x2003;(1),(sin &#x3b8;)/&#x3bb;=&#x2212;(sin &#x3b8;)/&#x3bb;&#x2003;&#x2003;(2),where

Objective lens element

An optical disk information device includes a laser light source that emits a luminous flux with a wavelength &#x3bb;, an objective lens having a numerical aperture NA, a splitting element, a photodetector, a central portion amplifier, at least two end portion amplifiers, an adder, a control signal processing section having a tracking switcher that inverts a polarity of a tracking control signal depending on whether a track scanned by a condensing spot corresponds to a land portion or a groove portion, and a gain controller that, when the polarity of the tracking control signal is inverted, switches gains of the central portion amplifier and the end portion amplifiers and sets the gain of the central portion amplifier substantially lower than the gain of at least one of the end portion amplifiers so as to reduce crosstalk from adjacent tracks in the optical disk.

Optical disk information device and information processing device

An objective lens () is configured to converge laser light of a first wavelength &#x3bb;(390 [nm]&#x2266;&#x3bb;&#x2266;430 [nm]), laser light of a second wavelength &#x3bb;(630 [nm]&#x2266;&#x3bb;&#x2266;680 [nm]), and laser light of a third wavelength &#x3bb;(750 [nm]&#x2266;&#x3bb;&#x2266;810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.

Optical head, objective lens, optical disc device, computer, optical disc player, and optical disc recorder

Assuming that third-order coma aberration per unit angle generated by tilt of BD () in recording or reproducing information on or from BD () is CMDbd, third-order coma aberration per unit angle generated by tilt of CD () in recording or reproducing information on or from CD () is CMDcd, third-order coma aberration per unit angle generated by tilt of a compatible objective lens () in recording or reproducing information on or from BD () is CMLbd, and third-order coma aberration per unit angle generated by tilt of the compatible objective lens () in recording or reproducing information on or from CD () is CMLcd, a sine condition deviation amount (SCbd) in recording or reproducing information on or from BD () is expressed by CMDbd+CMLbd, a sine condition deviation amount (SCcd) in recording or reproducing information on or from CD () is expressed by CMDcd+CMLcd, and the sine condition deviation amount (SCbd) and the sine condition deviation amount (SCcd) satisfy SCbd&#x3e;0 and SCcd&#x3c;0.

Objective lens, optical head, optical disk device, and information processing device

A ratio Xm of an information item recorded on an adjacent track relative to an information item recorded on a main track included in a first signal obtained from a first light flux having passed through a center region () is different from ratios Xs1 and Xs2 of the information items recorded on the adjacent track relative to the information items recorded on the main track included in second and third signals obtained from second and third light fluxes having passed through first and second end regions (), and a ratio of respective gains of a first waveform equalizer (), a second waveform equalizer (), and a third waveform equalizer () is determined so as to cancel the information item recorded on the adjacent track in each of frequency components of the first signal, the second signal, and the third signal.

Optical information device, cross-talk reduction method, computer, player, and recorder

A disclosed objective lens includes: a lens having an entrance surface and an emission surface; and an anti-reflection coat formed on the emission surface, wherein a transmittance T[%] of the anti-reflection coat when an incident angle of a first laser beam having a first wavelength &#x3bb;(390 nm&#x2266;&#x3bb;&#x2266;430 nm) is 0&#xb0;, and the transmittance T[%] of the anti-reflection coat when the incident angle of the first laser beam is 40&#xb0; satisfy 0.95&#x2266;T/T&#x2266;1.05, and a transmittance T[%] of the anti-reflection coat when an incident angle of a second laser beam having a second wavelength &#x3bb;(630 nm&#x2266;&#x3bb;&#x2266;680 nm) is 0&#xb0; and a transmittance T[%] of the anti-reflection coat when the incident angle of the second laser beam is 40&#xb0; satisfy 0.85&#x2266;T/T&#x2266;0.97.

An objective lens element which has excellent compatibility with optical discs having different base material thicknesses is provided. An objective lens elementhas optically functional surfaces on an incident side and an exit side. Either one of the optically functional surfaces is divided into an inner partB including a rotational symmetry axis and an outer partF which is a ring-shaped region surrounding the inner partB. On the inner partB, a plurality of discontinuous steps are provided. The plurality of steps change in height in the same direction from the optical axis toward the outer part, and each of the steps causes a constant optical path difference longer than the wavelength &#x3bb;to the first incident light beamand causes a constant optical path difference shorter than the wavelength &#x3bb;to the second incident light beam

An optical element has at least one surface divided into a plurality of regions and includes: a first region configured to converge light with a wavelength &#x3bb;onto a storage surface of a first optical disc and converge light with a wavelength &#x3bb;onto a storage surface of a second optical disc; and a second region formed around the outer circumference of the first region and configured to converge light with the wavelength &#x3bb;onto the storage surface of the first optical disc. The second region has a concave-convex structure concentrically formed on an aspheric surface and having a cross section being a saw teeth shape. The concave-convex structure is formed by a plurality of different saw teeth shapes, and the plurality of different saw teeth shapes respectively give different phase differences corresponding to substantially integer multiples of the wavelength &#x3bb;for light with the wavelength &#x3bb;

Optical element

An objective lens element having improved diffraction efficiency at least one of used wavelengths is provided. The objective lens element includes one surface including: a first region including an optical axis; and a second region surrounding the first region. A periodic first diffraction structure is formed on the first region, and a periodic second diffraction structure different from the first diffraction structure is formed on the second region. The objective lens element satisfies the following conditions.|1&#x2212;1|&#x3c;|2&#x2212;2|&#x2003;&#x2003;(1)|1|&#x2267;|2|&#x2003;&#x2003;(2)Here,

Objective lens element and optical head device including the same

A lens surface of an objective lens includes an optical surface formed of a plurality of annular optical surfaces which include an approximately stair-shaped cross section and which are annularly partitioned centered around an optical axis of the objective lens, and a plurality of connecting surfaces that connect the plurality of mutually adjacent annular optical surfaces to each other. The plurality of connecting surfaces include cylindrical connecting surfaces formed of a cylindrical surface centered around the optical axis and a conical connecting surface formed of a conical surface centered around the optical axis, and the conical connecting surface connects the annular optical surface and the annular optical surface.

Objective lens, optical head and optical disk device

Growing community of inventors

Osaka, Japan

Yoshiaki Komma