Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Akihiro Yasuda

Kousei Sano

Shin-ichi Kadowaki

Yoshiaki Komma

Daisuke Ogata

Keisuke Fujimoto

Noriyuki Tajima

Hidenori Wada

Noboru Katakabe

Yuuichi Kuze

Masaru Imai

Katsuya Watanabe

Sadao Mizuno

Kenji Fujiune

Takashi Kishimoto

Hideki Hayashi

Kazuhiro Hayashi

Shin-ichi Yamada

Shigemitsu Tani

Koichi Baba

Yasuhiro Tanaka

Yoshiyuki Shimizu

Seiji Nishino

Masahiro Samei

Kenji Asakura

Hideki Tatematsu

Joji Anzai

Hideaki Yamada

Katsuhiko Yasuda

Jouji Anzai

Masayuki Isayama

An optical pickup head is provided with a light source, a diffracting means for creating a plurality of diffracted beams, a converging means for focusing the diffracted beams onto an optical storage medium, a beam branching means for branching the plurality of beams reflected by the optical storage medium, and an optical detecting means for outputting a signal corresponding to the amount of light of the received beams. The optical detecting means has main beam light receiving portions and sub-beam light receiving portions. The amount of light of the first or higher order diffracted beams when they are substantially focused on and reflected by a focus plane of the plurality of information recording planes is equal to or greater than the amount of light of the zero order diffracted beam when it is reflected without focusing by a non-focus plane other then the focus plane of the plurality of information recording planes. The invention provides an optical pickup head where offset is not generated in the TE signals even during tracking with the objective lens when a two-layered disk is used.

Optical pickup head and information recording/reproducing device

The present invention provides a first light source () that emits light of a first wavelength, that at least either records onto or reproduces information from an information recording medium (), a light source () that emits light of a second wavelength that records onto or reproduces information from an information recording medium (), a light source () that emits light of a third wavelength that records onto or reproduces information from an information recording medium (), focusing means, an optical element () that passes light of the first wavelength and diffracts light of the second and third wavelengths, wherein the optical element () is an optical element in which grooves are formed in a substrate, wherein the expression:380 nm&#x2266;(&#x2212;1)&#xd7;&#x2266;420 nmis satisfied, where n is a refractive index of the substrate at a wavelength of 400 nm, and d (nm) is a depth per step of the grooves, and wherein the grooves are formed in two steps of depth d and depth

Optical element, optical head, optical information recording and reproduction apparatus, computer, image recording device, image reproduction device, server and car navigation system

A heating apparatus which can increase the temperature of a heating element to a target temperature in a short time and ensures temperature uniformity of the heating element. In the heating apparatus, when the specific resistance of a material of a heat generating layer of a heating roller is &#x3c1; (&#x3bc;'&#x3a9;cm), the average thickness of the heat generating layer is 5&#x3c1; (&#x3bc;m) or more but not more than 15&#x3c1; (&#x3bc;m), and the thickness error is 1.2&#x3c1; (&#x3bc;m) or less. For instance, when the heat generating layer is copper having a specific resistance of 1.7 (&#x3bc;&#x2032;&#x3a9;cm), the average thickness of the heat generating layer is 8-25 (&#x3bc;m), and the thickness error is 2 (&#x3bc;m) or less. Thus, the heating roller having a short heat increasing time and excellent temperature uniformity is provided.

Heating apparatus including electrically conductive heat producing layer providing short heat increase time and temperature uniformity

An optical disc device of the present invention includes spherical aberration changing means for changing spherical aberration occurring on a converging position of a light beam converged by a lens, an actuator for moving the spherical aberration changing means in a relatively precise manner, and an actuator for moving the spherical aberration changing means in a relatively rough manner. The optical disc device drives a second actuator and a third actuator based on a signal of spherical aberration detecting means and performs control so that spherical aberration is almost 0. The third actuator moves the spherical aberration changing means based on a direct current component included in a signal of the spherical aberration detecting means, and the second actuator moves the spherical aberration changing means based on an alternating current component included in the signal of the spherical aberration detecting means.

Optical disc device

A heating apparatus that enables an abnormally high temperature detection section that detects, when a heating element heated by means of electromagnetic induction reaches an abnormally high temperature, this abnormally high temperature, to operate speedily and reliably irrespective of the material and temperature characteristic of the heating element in a low-cost and compact configuration. In this apparatus, thermostatis disposed on the same side as exciting coilwith respect to heat generating beltand between winding bundles of a conductor wire of exciting coil. This allows coil guideto hold both thermostatand exciting coiland allows these wires and terminals to be concentrated on one location, thus making it possible to reduce the number of parts and assembling man-hours and configure the body of the apparatus in a low-cost and compact configuration. Furthermore, thermostatoperates reliably when heat generating beltreaches an abnormally high temperature irrespective of whether the material of heat generating beltis a magnetic member or not and whether the temperature of heat generating belthas exceeded a Curie temperature or not.

Heating apparatus, fixing apparatus and image forming apparatus

The present invention provides a first light source () that emits light of a first wavelength, that at least either records onto or reproduces information from an information recording medium (), a light source () that emits light of a second wavelength that records onto or reproduces information from an information recording medium (), a light source () that emits light of a third wavelength that records onto or reproduces information from an information recording medium (), focusing means, an optical element () that passes light of the first wavelength and diffracts light of the second and third wavelengths, wherein the optical element () is an optical element in which grooves are formed in a substrate, wherein the expression:380 nm&#x2266;(&#x2212;1)&#xd7;420 nmis satisfied, where n is a refractive index of the substrate at a wavelength of 400 nm, and d (nm) is a depth per step of the grooves, and wherein the grooves are formed in two steps of depth d and depth

Optical element, optical head, optical information recording/reproduction device, computer, video recording device, video reproduction device, server, and car navigation system

An optical head is provided that increases the light utilization efficiency and that can be adapted to high-speed recording and double-layer disks. A beam-shaping lens that shapes an elliptical beam emitted from a light source into a substantially circular beam has a pair of cylindrical surfaces that are curved in the same direction. The cylindrical surface that is closer to the light source is an aspherical surface, and the cylindrical surface that is closer to the light source is a spherical surface. Thus, an optical head is obtained, with which aberrations can be kept low, even when the beam-shaping magnifying power is about a factor 2.

Optical head, optical information recording/reproducing apparatus, computer, video recording/reproducing apparatus, video reproducing apparatus, server and car navigation system

In a fixing apparatus using an induction heating type of heating apparatus, there are provided an excitation apparatus that generates magnetic flux, an opposed core located opposite the excitation apparatus, a fixing belt that is induction-heated by the aforementioned magnetic flux, and magnetism masking elements that block magnetic paths corresponding to paper non-passage areas of fixing belt between the excitation apparatus and the opposed core. By blocking magnetic paths between the excitation apparatus and the opposed core by the magnetism masking elements, magnetic flux that induction-heats the fixing belt is effectively masked, and an excessive rise in temperature of paper non-passage areas of fixing belt is prevented.

Fixing device

An image heating apparatus is provided that enables the entire width of a heat-producing medium to be heated uniformly and an excessive rise in temperature to be prevented, without making the configuration complex. In a fixing unitin which this apparatus is applied, a fixing beltis an annular member that has an inner peripheral surface and an outer peripheral surface, and produces heat through the action of magnetic flux. An exciting coilis located in proximity to the outer peripheral surface of fixing beltand generates magnetic flux that acts upon fixing beltA suppression memberis located in proximity to inner peripheral surface of fixing beltand reduces, of the magnetic flux generated by exciting coilmagnetic flux that acts upon a paper non-passage area of fixing belt

Image heating device and image forming device

As a cooling mechanism that cools the entire paper passage area of a heat-producing belt, a rotational drive method of the heat-producing belt is employed and the heat-producing belt is cooled by rotational cooling by being made to idle when paper is not being passed through. An excitation apparatus and the above-described cooling mechanism are controlled so that recording paper is not passed through and the heat-producing belt is cooled while being heated over the heating width when the small-size recording paper is passed through until the temperature detected by a paper non-passage area temperature detecting sensor is at or below a predetermined fixing temperature. This fixing apparatus enables an excessive rise in temperature of a paper non-passage area of the heat-producing belt to be efficiently eliminated, and the temperature distribution of heat-producing belt to be made uniform in a short time.

Fixing device and temperature control method

A fixing apparatus can prevent an excessive rise in temperature of a paper non-passage area due to diverted flow of magnetic flux from a paper passage area of a heat-producing element to a paper non-passage area thereof has a small configuration. A center core is rotated by a rotation section, bringing cutaway parts to a magnetic path masking position, and the degree of magnetic coupling between the center core and a heat-producing roller is weakened, suppressing an excessive rise in temperature of paper non-passage areas of the heat-producing roller. With this fixing apparatus, switching of the intensity of magnetic coupling between the center core and heat-producing roller can be performed simply by rotating the center core. Also, with this fixing apparatus, it is not necessary for magnetism suppressing elements to be provided as separate members, enabling the configuration to be made simpler and less expensive.

An optical information processing apparatus includes: an optical head for irradiating an optical information recording medium with light, converting the light reflected by the optical information recording medium into a head signal and outputting the head signal; a signal quality index detector for detecting a signal quality index representing quality of the head signal on the basis of the head signal; and a two-dimensional probe for varying the focal position and the spherical aberration of the light radiated onto the optical information recording medium so as to search for a focal position and a spherical aberration that optimize the signal quality index detected by the signal quality index detector.

Optical information processing apparatus and method of processing optical information

An optical head apparatus capable of stably obtaining a detection signal of spherical aberration even with a high density optical disk. A spherical aberration error signal is obtained by: dividing the returning light from the optical disk into a transmitted light and a diffracted light; reproducing information with the transmitted light having a larger amount of light while dividing the diffracted light having a small amount of light into two regions, i.e., region near the optical axis and a region distant from the optical axis; determining amounts of focus deviation in respective regions as focus error signals; and taking the difference signal therebetween. Thus, it is possible to detect the amount of spherical aberration with the SN ratio of the information reproducing signal kept at high level.

Optical head apparatus, optical information recording and reproducing apparatus, method for detecting aberration and method for adjusting optical head apparatus

Growing community of inventors

Katano, Japan

Akihiro Yasuda