摘要:
A magneto-optical disk drive that prevents the track shift signal from overlapping the MO signal, even when the optical head projects a divergent spherical wave onto the beam splitter. This objective is realized by a magneto-optical disk drive that uses an optical head which emits a divergent spherical wave onto a beam splitter surface of a beam splitter. Since the tracking error signal, which is overlapped by the MO signal of the MO detection unit, is synchronous with the tracking signal, a correction circuit is used to overlap the MO signal with the tracking error signal and to eliminate errors caused when the track shift signal overlaps the MO signal.
摘要:
An optical device including a light source for emitting diverging light, a polarizing beam splitter for transmitting or reflecting the diverging light according to a polarized light component, a collimator lens for converting the diverging light transmitted through the polarizing beam splitter into collimated light, and an objective lens for focusing the collimated light on an object. The optical device further includes an optical element arranged between the collimator lens and the objective lens for producing a phase difference of +90°±15° or −90°±15° between P-polarized light and S-polarized light. The optical element has a principal axis perpendicular or parallel to a plane of incidence of the diverging light on the polarizing beam splitter. For example, the optical element is provided by a quarter-wave plate having an optic axis perpendicular or parallel to the plane of incidence of the diverging light on the polarizing beam splitter.
摘要:
There is disclosed a compact optical information storage apparatus in which noise attributed to wobbling or the like is reduced and high-density recording is possible. An optical device 410 comprises a reflective surface 64 including a main portion for reflecting a signal light reflected by a separation surface 61 in a predetermined direction, and a mask portion 411 having an optical property different from the optical property of the main portion.
摘要:
A high precision laser beam scanner is provided which is able to shape a beam generated by a laser, suppress the influence of jitter of a scanning beam due to mode hopping of a semiconductor laser, and reduce aberration of the scanning beam. A beam source generates a semiconductor laser beam, which is diffracted by a rotary hologram, forming a scanning beam on a surface to be scanned. An aberration correcting stationary hologram is disposed between the beam source and the rotary hologram. The stationary hologram is constructed with an object wave and a reference wave, which interfere on a stationary hologram substrate subject so that an aberration of the scanning beam on the surface to be scanned shall be corrected. The object wave is a spherical wave which has an aberration, a wave length shorter than that of the semiconductor laser beam, and an incident angle which is not vertical but is inclined with respect to the stationary hologram substrate. A method for fabricating the laser beam scanner is also provided.
摘要:
An optical head including a first dielectric layer having a first refractive index, a pair of second dielectric layers located adjacent to the first dielectric layer on both sides thereof, each of the second dielectric layers having a second refractive index larger than the first refractive index, a pair of third dielectric layers located adjacent to the second dielectric layers, and a pair of fourth dielectric layers located adjacent to the third dielectric layers, each of the fourth dielectric layers having a third refractive index larger than the first refractive index. Light is incident on the optical head in a direction orthogonal to a layering direction of the first to fourth dielectric layers. The first dielectric layer and each of the third dielectric layers have different refractive indices or different thicknesses.
摘要:
There are disclosed an optical storage device for accessing an optical recording medium such as a phase change type of optical disk and an optical magnetic disk, and a liquid crystal device preferably applicable to such a optical storage device. The liquid crystal device has a structure that two liquid crystal layers, each of which has stripe-like shaped electrodes arranged in a direction perpendicularly intersecting one another, are superposed. This structure makes it possible to effectively correct an aberration caused by a change in a depth from a surface of an optical recording medium to a condensing point, for example, in cases of unevenness in thickness of a protective layer and a multi-layer recording.
摘要:
A tandem type color printer, having optical beam scanning units and corresponding photosensitive drums, which detects a positional shift of a scanning locus occurring on a corresponding one of the plurality of photosensitive drums, and automatically corrects the detected positional shift of the scanning locus. A detecting window, in which a beam transmission time varies with a change in the beam scanning position, is provided at each of the start end side and the terminal end side of each of a plurality of beam scanning loci in a mask plate. The mask plate is arranged between the optical beam scanning units and the photosensitive drums, to provide output of a detection signal corresponding to the incident time of the transmission beam resulting from beam scanning by a light source, and thus determines and corrects the direction and the amount of positional shift of the scanning locus.
摘要:
An optical pickup for reading out information from an information recording media, such as an optical diskette, comprises a light source for irradiating light beam onto an optical diskette, an optical sensor for detecting the light beam reflected at the optical diskette, and an optical system including a wave plate and two hologram lenses. The first hologram lens diffracts the light beam from the light source, and the second hologram lens transmits the same light beam. On the other hand, the second hologram lens diffracts the reflected light beam from the optical diskette toward the optical sensor, and the first hologram lens transmits the same reflected light beam.
摘要:
A magnetic disk device performs magnetic recording by generating a magnetic field using an electric current on a light-irradiated surface of a recording medium. A head unit is formed by laminating an optical film that transmits a light and a metal film through which the electric current flows. A light exposing unit irradiates the light in such a manner that the light is transmitted through the optical film and irradiated on a surface of the recording medium. An electric-current output unit outputs the electric current to the metal film.
摘要:
An optical head including a first dielectric layer having a first refractive index, a pair of second dielectric layers located adjacent to the first dielectric layer on both sides thereof, each of the second dielectric layers having a second refractive index larger than the first refractive index, a pair of third dielectric layers located adjacent to the second dielectric layers, and a pair of fourth dielectric layers located adjacent to the third dielectric layers, each of the fourth dielectric layers having a third refractive index larger than the first refractive index. Light is incident on the optical head in a direction orthogonal to a layering direction of the first to fourth dielectric layers. The first dielectric layer and each of the third dielectric layers have different refractive indices or different thicknesses.