摘要:
Disclosed is an optical head in which position adjustment of a photodetector light receiving surface or component parts may be simplified, production costs may be reduced and operational reliability may be improved. The optical head includes a light source 22, radiating light of a preset wavelength, an objective lens 27 for condensing the outgoing light from the light source 22 on an optical disc 2 and for condensing the return light from the optical disc 2, a beam splitter 25 for branching the optical path of the return light reflected by the optical disc 2, and for collimating the branched return light so as to be parallel to the outgoing light from the light source 22, a composite optical component including a splitting prism 30 arranged on a site of incidence of the branched return light for spatially splitting the return light, and a light receiving unit for receiving plural return light beams spatially split by the splitting prism 30 for producing focusing error signals.
摘要:
An optical pickup device is disclosed. The device includes: a light source that emits a light beam of a predetermined wavelength of about 405 nm; an objective lens being a plastic lens provided with, on at least one surface, diffraction means of a zone diffractive structure suppressing generation of aberration to be caused by a temperature change, and has a numerical aperture of 0.82 or larger for gathering the light beam emitted from the light source with respect to an optical disk; and a collimator lens disposed between the light source and the objective lens, and derives a substantially-collimated light by converting an angle of divergence of the light beam emitted from the light source.
摘要:
An optical pickup apparatus and an optical disc apparatus are adapted to raise the efficiency of utilization of the lasers of the apparatus for accurately detecting tracking errors by raising the intensity ratio of the beam of the 0-th order to the beams of the ±1st orders produced by splitting of the laser beam of the wavelength to be subjected to division by three. The optical pickup apparatus includes a light emitting section for emitting a first laser beam having wavelength λ1 and a second laser beam having wavelength λ2 different from the wavelength λ1, a surface relief type first diffraction grating having a phase height of two steps produced by being equipped with a first phase grating and a second phase grating arranged at opposite sides of the first phase grating and adapted to split the laser beam of the wavelength λ1 into three beams and transmit substantially all of the laser beam of the wavelength λ2, a surface relief type second diffraction grating having a phase height of two steps produced by being equipped with a first phase grating and a second phase grating arranged at opposite sides of the first phase grating and adapted to split the laser beam of the wavelength λ2 into three beams and transmit substantially all of the laser beam of the wavelength λ1, an objective lens for converging the laser beams emitted from the light emitting section onto an optical disc, an optical element for branching the optical paths of return light reflected by the optical disc, and a light receiving section for receiving the return light branched by the optical element.
摘要:
A head position controlling device in which the head position may be controlled accurately even with a magneto-optical disc having regions with different reflectance values. A gap sensor consisting of a light emitting element 5 and light receiving elements 6 and 7 are arrayed along the track direction of a magneto-optical disc to prevent unequilibrium in the volume of received light at the light receiving elements 6 and 7.
摘要:
An optical pickup device is disclosed. The device includes: a light source that emits a light beam of a predetermined wavelength of about 405 nm; an objective lens being a plastic lens provided with, on at least one surface, diffraction means of a zone diffractive structure suppressing generation of aberration to be caused by a temperature change, and has a numerical aperture of 0.82 or larger for gathering the light beam emitted from the light source with respect to an optical disk; and a collimator lens disposed between the light source and the objective lens, and derives a substantially-collimated light by converting an angle of divergence of the light beam emitted from the light source.
摘要:
An optical pickup device is provided which includes a first diffraction grating (45) that splits a light beam emitted from a light-emitting/-detecting element (31) into a zero-order light beam and positive and negative first-order light beams, a second diffraction grating (46) that diffracts return light from an optical disk (2) for traveling along a light path separate from that of the outgoing light, and a third diffraction grating (47) that corrects the deviation of the light path by diffracting the positive first-order light beam diffracted by the second diffraction grating (46). The light-emitting/-detecting element (31) provides a focusing error signal FE by detecting the negative first-order light beam, and a tracking error signal by detecting return portions of the positive and negative first-order light beams from the first diffraction grating (45).
摘要:
An optical type record card reader according to the present invention is provided with a line sensor (10) for reading an information by a reflected light from a track of an optical type record card (1) irradiated by a light source (4) and in which optical type record card an information is recorded on a record medium (1A) as a plurality of parallel tracks which can be read out optically, a cylindrical lens (11) located rotatably between the optical type record card (1) and the line sensor (10) and an azimuth error detecting circuit for detecting an azimuth error generated between the track and the line sensor (10), wherein the cylindrical lens (11) is rotated by the detected output of the azimuth error detecting circuit to thereby correct the azimuth error. Thus, it becomes possible to correct the azimuth error of the projected image a sub-track of the optical type record card onto the line sensor smoothly, highly precisely and rapidly by the rotation of the cylindrical lens.
摘要:
An optical pickup apparatus and an optical disc apparatus are adapted to raise the efficiency of utilization of the lasers of the apparatus for accurately detecting tracking errors by raising the intensity ratio of the beam of the 0-th order to the beams of the ±1st orders produced by splitting of the laser beam of the wavelength to be subjected to division by three. The optical pickup apparatus includes a light emitting section for emitting a first laser beam having wavelength λ1 and a second laser beam having wavelength λ2 different from the wavelength λ1.
摘要:
In the present invention, the an electronic mail transmission terminal device encrypts an electronic mail and transmits the encrypted mail. An electronic mail server device, when the encrypted mail is received, transmits a reception notification mail, which notifies reception of the encrypted mail, to an electronic mail reception terminal device in which a receiver of the encrypted mail is stored. An electronic reception terminal device, when the reception notification mail is received from the electronic mail server device, indicates reception of the encrypted mail to the receiver, requests electronic mail server device to transmit the encrypted mail after performing personal authentication of the receiver. Further, the electronic reception terminal device decrypts the encrypted mail.