4876 results about "Optical pickup" patented technology

An optical pickup apparatus comprises first, second and third light sources to emit light fluxes of wavelength lambda1, lambda2 and lambda3 for conducting recording and / or reproducing information for first, second and third optical information recording mediums having respective protective substrates of thickness t1, t2 and t3 and a diffractive optical element located on a common optical path for the first, second and third light sources. A converged-light spot is formed on the first optical information recording medium with m-th order diffracted-light ray of the wavelength lambda1, on the second optical information recording medium with n-th order diffracted-light ray of the wavelength lambda2, and on the third optical information recording medium with k-th order diffracted-light ray of the wavelength lambda3 generated by the diffractive optical element respectively, wherein one of m, n and k is different from one of other two numbers.

An objective lens module includes a light-converging lens that is coaxially disposed with respect to an optical axis of first laser light having a first wavelength, and a transmission-type diffractive optical element that is coaxially disposed to cause diffracted light of first laser light to be incident on the light-converging lens. The diffractive optical element has an incident surface and an emergent surface, and first, second, and third regions that are provided on at least of the incident surface and the emergent surface inthe vicinity of the optical axis, and are sequentially defined according to different radius distances from the optical axis to have different diffraction gratings of different diffraction angles, respectively. The first region diffracts odd-order diffracted light of first laser light to the light-converging lens, the second region diffracts even-order diffracted light of first laser light to the light-converging lens, and the third region diffracts even-order or zero-order diffracted light of first laser light to the light-converging lens, such that the light-converging lens converges diffracted light from the first, second, and third regions with a predetermined numerical aperture.

A first diffractive optical element pattern with a pattern pitch that is no greater than a wavelength of incident light is formed on a first main surface of substrate such as a glass plate. Second diffractive optical element patterns are formed at positions that are respectively incident to positive first-order diffracted light and negative first-order diffracted light produced by the first diffractive optical element pattern. Negative first-order diffracted light produced by each second diffractive optical element pattern is incident upon a boundary face of the substrate at an angle that is smaller than the critical angle, and so exits the substrate.

To provide an optical pickup device and optical disk device capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser. An optical pickup device comprising light sources for respectively emitting a plurality of different wavelengths of light, unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part.

An optical pickup device, comprises a first light source emitting light with a short wavelength; a second light source emitting s light with a wavelength longer than that of the first light source; an optical member guiding the light from the first light source and the light from the second light source on almost the same optical path; a focusing member focusing the light from the optical member; a movable lens provided between the optical member and the focusing lens; and a drive member driving the movable lens, wherein a position of the lens when at least one of recording and reproducing of information is carried out on a medium using the light from the first light source is made different from a position of the lens when at least one of the recording and reproducing of information is carried out on the medium using the light from the second light source.

An optical pickup apparatus includes first and light sources; an objective lens; a spherical aberration correcting optical unit; and a chromatic aberration correcting optical element which includes a diffractive surface on at least one of optical surfaces of the chromatic aberration correcting optical element such that a diffractive structure which is constructed by a plurality of ring-shaped zones separated by fine steps is formed on the diffractive surface, wherein the depth of steps along an optical axis is designed so that n2 which is a diffraction order of a diffracted ray having a largest diffraction efficiency among diffracted rays caused when the second light flux enters into the diffractive structure, is lower order than n1 which is a diffraction order of a diffracted ray having a largest diffraction efficiency among diffracted light rays caused when the second light flux enters into the diffractive structure.

A semiconductor laser device includes a Si(100) substrate in which a recess having an opening and a bottom face surrounded by inner wall surfaces is formed, a semiconductor laser element placed on the bottom face, and a translucent sealing glass, mounted on top of the Si(100) substrate, which seals the opening. The laser light emitted from the semiconductor laser element is reflected by a metallic reflective film formed on the inner wall surface and then transmits through the sealing glass so as to be emitted externally.

A visible light characteristic changing layer is formed in a location which can be viewed from a part of a label surface of an optical medium. The optical medium is set on a turntable of an optical disk unit, which may be rotated at a constant angular velocity, while the power of a laser beam is modulated in accordance with image data. The optical pickup operates at a first power level when changing a visible light characteristic of the optical medium to form the visible information and the optical pickup operates at a lower power level when not changing a visible light characteristic of the optical medium. As a result, a visible-light reflectivity of the visible light characteristic layer is changed, thereby forming an image corresponding to the image data on the label surface, A tracking servo operation is turned off while the optical pickup forms the visible information.

Disclosed is an electrowetting device. The electrowetting device includes a conductive or polar liquid material, and an electrode applying voltage to the liquid material through a dielectric layer. In the electrowetting device, the dielectric layer is formed as an anodized portion made of a metal oxide formed by anodizing the electrode, and a voltage applying unit applying voltage between the electrode and the liquid material and a polar capacitor are placed between the electrode and the liquid material.

In a slim type optical disc drive, an optical pickup unit and an optical pickup transport assembly are installed on a main base disposed in a housing having a lower case and an upper case. A spindle motor is mounted on a tray so as to slide in and out of the housing. A spindle motor printed circuit board is mounted on the tray, and a main printed circuit board is fixed to the lower case. A flexible printed circuit connects the spindle motor and main printed circuits boards. The tray includes a table which supports the spindle motor, and side frame bars located at sides of the tray and spaced apart from the table. A pair of guide ribs are arranged in the housing to guide the movement of the table. In the slim type optical disc drive, only the spindle motor is disposed on the tray.

In an optical disk apparatus, an optical pickup includes an actuator for driving an object lens, and a sensed signal output part for making it possible to generate a tracking error signal and a lens error signal by addition / subtraction, and a signal processor includes a servo signal generator for generating a tracking error signal and a lens error signal on the basis of a signal supplied from the sensed signal output part, and a tracking offset correction quantity signal generator supplied with the lens error signal to output a tracking offset correction quantity signal. DC (direct current) offset correction is conducted by conducting addition / subtraction between the tracking error signal and both the lens error signal and the tracking offset correction quantity signal.

An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted ray of the second light flux, where n stands for an integer other than zero.