摘要:
Disclosed are a hologram unit of an optical pickup which has a main hologram and auxiliary alignment holograms around the main hologram thereof and a method of attaching a hologram plate of the optical pickup comprising the steps of: illuminating an object with an LD; forming an LD radiant point on a monitor through a microscopic lens, and a plurality of radiant points around the LD radiant point by auxiliary alignment holograms; and aligning the LD with the hologram plate by moving the hologram plate so as to form the LD radiant point in the center of the plurality of radiant points.
摘要:
An annular shutter mirror which can selectively shut off a part of light beams progressing toward a target in the progressing direction thereof. The annular shutter mirror utilizes a fixed reflection face to reflect an incident light beam at a constant angle in accordance with an incident angle of the incident light beam. Around the periphery of the fixed reflection face, at least one flexible reflection face is formed in a shape of annular band. This at least one flexible reflection face selectively reflects an incident light beam at an angle different from a reflective angle of the fixed reflection area in accordance with an application condition of an electrical field.
摘要:
A different wavelength type of optical source module which generates light beams different in wavelength. In the optical source module, laser diodes are provided to be opposed to each of reflective films which is arranged to make a shape of a mountain. These respective laser diodes generates laser light beams different in wavelength. The light beams generated at the laser diodes are reflected by the reflective films at a right angle to progress along the same path.
摘要:
Holographic memory including a plurality of HOEs stacked in a vertical direction for two dimensional addressing of a recording medium for increasing a recording capacity and improving productivity and cost.
摘要:
A light source module with two wavelengths that is adapted to generate laser beams different in wavelength. In the light source module, a hologram optical element (HOE) is used to allow a first laser beam generated at a first light source and a second laser beam generated at a second light source to progress along same path. The HOE diffracts the second laser beam to change a progressive path of the second laser beam into that of the first laser beam. The first light source generates the first laser beam having a different wavelength from the second laser beam generated at the second light source.
摘要:
An optical pickup system capable of recording/reading out information on/from a mini disc or magneto-optical disc includes a polarized beam splitter (PBS) for fully reflecting beams of S-wave component from a laser diode or reflected from the disc while partially reflecting and partially transmitting beams of P-wave component, a reflection mirror placed between the PBS and disc for reflecting the beams transmitted through the PBS toward the disc while reflecting the beams reflected from the disc toward the PBS, a first photodetector having plural split areas for detecting a focus error and a tracking error according to the beams focusing on respective split areas, a hologram element for allowing three beams from a grating to be incident to the PBS or diffracting the beams of P-wave component transmitted through the PBS to focus the diffracted beams on the first photodetector, a second photodetector having six split areas for detecting the information recorded on the disc according to the beams focusing on respective split areas thereof, and a Wollaston prism placed between the PBS and second photodetector for separating mixed beams of P-wave and S-wave components from the PBS to allow the separated beams to be incident to the second photodetector, thereby decreasing the number of optical elements to improve readout speed of the information on the disc and simplifying the structure of the optical pickup system to reduce manufacturing cost.
摘要:
Optical pick-up system and method for accurately reading information recorded on an optical disc. The invention makes it possible to determine the kind of an error occurring upon reading information recorded on an optical disc by light beams from a light source, by using error detectors, and to correct accurately the error by driving a focusing lens, thereby capable of rapidly correcting errors such as tracking/focusing errors, providing a light and compact construction and improving a reliance, so as to solve problems of a high sensitivity to variations, a poor assembling ability, a bulky construction and a degraded reliance, encountered in optical devices which have been generally used for reading information recorded on optical discs.