摘要:
A front photo detector (FPD) of an optical pick-up for an optical recording and playing apparatus having no gain selection switch, a simplified configuration, an improved prevention of an abnormal operation due to an error in gain selection, and improved reliability. The front photo detector includes a photo diode unit, a current-voltage amplifying circuit, and a voltage amplifying unit. The photo diode unit outputs current proportional to the power of the light emitted from one of a plurality of laser diodes. The current-voltage amplifying circuit converts the current output from the photo diode unit into a voltage. The voltage amplifying circuit amplifies the voltage output from the current-voltage amplifying circuit by a predetermined gain.
摘要:
A semiconductor laser for generating a laser beam and an optical pickup for recording/reproducing information using the semiconductor laser as an optical source are provided. The semiconductor laser includes an aperture member on an emitting end thereof to perform high-density memory recording/reproducing through the reduction of an optical spot. The aperture has a hole whose diameter is smaller than the width of the active region of the semiconductor laser, to thereby restrictively emit the laser beam via the hole so that the optical spot formed on an optical disk is reduced. Thus, high-density memory recording/reproducing, which is useful for miniaturized information processors, can be realized.
摘要:
An optical disk having an improved structure is provided so that about 15 gigabytes or more can be recorded on each information recording surface. The optical disk includes at least one information substrate having an incident surface where light for recording/reproducing signals is input and a recording surface where information signals are recorded, and at least one reflection layer formed by being coated on the recording surface for reflecting at least a part of incident light. In the optical disk, assuming that the entire thickness of the optical disk is D and the distance between the incident surface and the recording surface of the information substrate is D1, the inequality 0.20≦D1/D≦0.38 is satisfied. Also, the optical disk includes a first information substrate having an incident surface where light for recording/reproducing signals is input and a first recording surface where information signals are recorded, a first reflection layer formed by being coated on the first recording surface for reflecting at least a part of incident light, and a second reflection layer formed on the second recording surface for reflecting at least a part of incident light. In the optical disk, assuming that the entire thickness of the optical disk is D and the distance between the incident surface and the first recording surface of the first information substrate is D1, the inequality 0.20≦D1/D≦0.38 is satisfied.
摘要翻译:提供了具有改进结构的光盘,使得每个信息记录表面上可以记录大约15吉字节或更多。 光盘包括至少一个具有入射表面的信息衬底,其中输入用于记录/再现信号的光和记录信息信号的记录表面,以及至少一个反射层,其被形成在记录表面上以至少反射 一部分入射光。 在光盘中,假设光盘的整个厚度为D,信息基板的入射表面和记录表面之间的距离为D1,则满足不等式0.20 <= D1 / D <= 0.38。 此外,光盘包括具有入射面的第一信息基板,其中输入用于记录/再现信号的光,以及记录信息信号的第一记录表面,通过涂覆在第一记录表面上形成的第一反射层,用于反射 入射光的至少一部分,以及形成在第二记录面上的第二反射层,用于反射入射光的至少一部分。 在光盘中,假设光盘的整个厚度为D,并且第一信息基板的入射表面和第一记录表面之间的距离为D1,则满足不等式0.20 <= D1 / D <= 0.38。
摘要:
An optical pickup assembly includes a base, a bobbin having an objective lens mounted thereon, the bobbin being installed at the base so as to be movable and having a pair of first side surfaces parallel to a radial direction of a disk and a pair of second side surfaces parallel to the tangential direction of a disk track, a focus coil wound around the bobbin for driving the objective lens in a focus direction, a track coil installed at the first side surfaces for driving the objective lens in a radial direction of the disk, a driving magnet installed at the base to face the first side surfaces, a tilt coil installed at the second side surfaces for driving the objective lens in response to the relative inclination between the objective lens and the disk, a first tilt magnet installed at the base such that one polarity thereof faces the tilt coil, a second tilt magnet installed at an upper portion of the first tilt magnet such that another polarity opposite to the one polarity thereof faces the tilt coil, an inclination detector for detecting the relative inclination between the objective lens and the disk, and a cover coupled to the base to protect the objective lens.
摘要:
An optical pickup includes a variable iris having a numerical aperture is adjusted according to wavelength of light and can be compatibly used for discs having respectively different specifications. The optical pickup includes a plurality of laser sources respectively emitting light of different wavelengths, an objective lens for focusing the light emitted from the laser sources into an optical spot optimized to each information recording surface of the plurality of discs, at least one photo detector for detecting the light reflected from the information recording surfaces of the corresponding discs where the optical spot is focused and passed through the objective lens, an optical element for adjusting an optical path so that the light emitted from the laser sources is directed toward the objective lens and the light emitted from the objective lens is directed toward the at least one photo detector, and a variable iris coupled between the laser sources and the objective lens, selectively operating according to the wavelength. The optical pickup can be compatibly used for discs having respectively different specifications irrespective of the thicknesses of the discs. The variable iris selectively operates in the case that light of two or more wavelengths is used, to thereby provide an effect of accomplishing an optimal optical spot on the discs.
摘要:
A lens device which can be used as an objective lens in an optical pickup apparatus includes an objective lens provided along a light path facing a disc and having a predetermined effective diameter, and light controlling means provided along the light path for controlling the light in an intermediate region between near and far axes of an incident light beam, thus providing a simplified and inexpensive device for using discs of differing thickness in a single disc drive, by reducing the spherical aberration effect.
摘要:
An optical pickup for correcting an astigmatic difference of a light by using a collimating lens arranged at an angle with respect to the thickness direction of an active layer of a light source and parallel to the width direction of the active layer, for collimating the light emitted from the light source, is provided. The collimating lens is arranged between an edge emitting laser diode having an active layer and a beam splitter, and corrects the astigmatic difference of the light emitted from the edge emitting laser diode. Therefore, a compact optical pickup can be achieved since additional optical elements for correcting the astigmatic difference of the laser beam are not required.
摘要:
An objective lens device having two light control surfaces and an optical pickup able to adopt disks having different thicknesses as a recording medium. The objective lens device includes an objective lens arranged along an optical path parallel to the disks, and first and second control portions formed in a light incident surface of the objective lens, a light emitting surface thereof, or an extra transparent member. Therefore, two disks having different thicknesses are compatible as a recording medium, and light interference occurring when using a thick disk can be decreased.
摘要:
An object pickup device includes a light source, an object lens for concentrating light generated from the light source onto an optical disk, a photodetector for detecting a signal from the light reflected from the optical disk, a disk detecting portion for detecting the light quantity in a light spot concentrated on the optical disk by the object lens and for detecting the optical disk type, a focus offset calculating portion for calculating a focus offset corresponding to the detected disk type, a focus servo portion for performing a focus servo mechanism according to the signal calculated from the focus offset and the signals detected in the photodetector, and a light output optimizing means for optimizing the light output of the light source according to the calculated focus offset signal. Meanwhile, a controlling method of a light output in the optical pickup device includes a disk kind detecting step, a focus offset calculating step, a focus offset adjusting step, and a compensating a focus and track error step.
摘要:
In a method and an apparatus for correcting aberration due to optical disk tilt, the apparatus includes a correction plate through which a first light beam passes by an object lens in an optical disk, a light source and a photo detector for generating and receiving a second light beam to detect the magnitude of the optical disk tilt, respectively, and an actuator for inclining the correction plate based on the detected signal. The correction plate has the same optical properties as those of the substrate of the optical disk, irrespective of the optical pick surroundings and offset the aberration due to the optical disk tilt. Therefore, while the best performance of the optical pickup is ensured, adverse effects caused by the aberration due to the optical disk tilt can be eliminated through simple circuitry.