Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Fumitomo Yamasaki

Yoshiaki Komma

Toshiyasu Tanaka

Kanji Wakabayashi

Kousei Sano

Akihiro Arai

Katsuhiko Hayashi

Hideki Aikoh

Shin-ichi Kadowaki

Hiroaki Yamamoto

Tomotada Kamei

Katsuhiko Yasuda

Michihiro Yamagata

Joji Anzai

Eishin Mori

Noriaki Terahara

Tohru Nakamura

Yasuhiro Tanaka

Osamu Kajino

Kazuhiro Minami

Tomoaki Tojo

Yasumori Hino

Sadao Mizuno

Junichi Asada

Takao Hayashi

Masahito Nakao

Takeshi Ohta

Shinsuke Hatanaka

Takayuki Nagata

Hironori Tomita

Takashi Nishihara

Naohiro Kimura

Takuya Wada

Yoshifumi Takasu

Yohichi Saitoh

Seiji Hoshi

Hiroshi Shiroiwa

Kuzuhiro Minami

An optical pickup includes an optical base mounted with at least one optical element, a light source that supplies light incident on the at least one optical element, and a tilt spacer that is disposed between the light source and the optical base to adjust a characteristic of the light that enters the optical base. With the characteristic of the light that enters the optical base adjusted by the tilt spacer, the optical base and the light source are fixed directly to each other.

Optical pickup

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 () 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

The present application discloses detection lens provided with lens portion and flange portion including first surface connected to lens portion and second surface opposite to first surface. Flange portion includes base along optical axis of lens portion, and first to fourth projections projecting from base. First and second projections are point-symmetric around optical axis. Third and fourth projections are point-symmetric around optical axis. Flange portion excludes projection extending beyond second surface. First projection includes first intersecting surface which intersects with first axis. Second projection includes second intersecting surface which intersects with first axis. Third projection includes third intersecting surface which intersects with second axis. Fourth projection includes fourth intersecting surface which intersects with second axis. First distance between first and second intersecting surfaces is longer than second distance between third and fourth intersecting surfaces.

Detection lens, lens unit, optical pickup device, optical disc device, computer, optical disc player and optical disc 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 that can suppress occurrence of an aberration is disclosed. Sawtooth-like diffraction structures having different height and cycles (pitches) are provided on an inner part Rand an outer part R, respectively. A curved surface Mextending at an intermediate level of recesses and projections of the sawtooth-like diffraction structure provided on the inner part R, and a curved surface Mextending at an intermediate level of recesses and projections of the sawtooth-like diffraction structure provided on the outer part Rare smoothly connected to each other. Even when wavelength of the light source and/or the environmental temperature change, a phase shift does not occur between the inner part Rand the outer part R, and a decrease in diffraction efficiency and occurrence of an aberration can be suppressed.

Objective lens element and optical pickup device

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

An optical system for optical pickup includes a magnification conversion optical element moving along an optical axis direction in accordance with each of optical recording medium recording surfaces, and an objective lens element converging a light beam incident through the magnification conversion optical element, to form a spot on a corresponding one of the recording surfaces, and satisfies the following formula: 4.0&#xd7;10&#x3c;Mn/(tn&#x2212;tc)&#xd7;f&#x3c;6.0&#xd7;10. Here tc is the thickness [&#x3bc;m] of a recording-medium base material at which a third-order spherical aberration occurring when a parallel light beam is incident on the objective lens element is the minimum, f is the focal length [mm] of the objective lens element, and Mn is the imaging magnification of the objective lens element when a spot is formed through a thickness tn [&#x3bc;m]of the base plate.

Optical system for optical pickup

A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a photodetector section receiving the beam, reflected from the disc, at divided areas on its photodetection plane and outputting light detection signals from those areas; and a tilt detecting section for detecting a relative tilt between the lens and disc based on the detection signals. The tilt detecting section generates a first push-pull signal PPbased on the detection signals supplied from a first group of areas, which are arranged symmetrically to a virtual reference line drawn parallel to a disc radial direction and crossing an optical axis, also generates a second push-pull signal PPbased on the detection signals supplied from a second group of areas, different from the first group and also arranged symmetrically to the reference line, changes coefficients k according to the location of the lens in a disc radial direction, and generates a tilt detection signal TLT by TLT=PP&#x2212;k&#xd7;PP

Optical head and optical disc device

An object of the present invention is to reduce the influence of a stray light incident on a light receiving device by reflection of an unnecessary diffraction light not contributing to write or read on a disc surface at write or read of an optical disc having a large surface reflectivity with respect to an information recording surface. A position in which a diffraction light with an n-order in an advancing path and the n-order in a returning path, reflected on the information recording surface of a first information recording medium, is focused by a condensing lens is different from a position in which a diffraction light different from the n-order diffraction light in at least one of the advancing path and the returning path, reflected on a surface of the first information recording medium, is focused by the condensing lens.

Growing community of inventors

Nara, Japan

Fumitomo Yamasaki