KR880003298A - Optical head unit - Google Patents

Abstract

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Description

Optical head unit

Since this is an open matter, no full text was included.

1 is a schematic block diagram showing an optical head device according to an embodiment of the present invention.

2 is a diagram for explaining a lattice trajectory.

Claims (11)

When the semiconductor laser light source, the light beam emitted from the light source is reflected by the first surface, the light beam splitting element diffraction-separated into several light beams of the 0th order diffracted light and the other diffracted light at the same time, and the light beam splitting element is reflected and separated by the beam splitting element A condensing lens means for condensing the light flux as a plurality of light spots on the optical information storage medium, reflected by the information surface of the optical information storage medium, and retransmitted by the condensing lens means, so that the first surface of the light beam separation element and It consists of a photodetector which receives the light beam passing through the second surface and photoelectrically changes it, and detects the focal shift of the disk condensing light beam by the deformation of the zeroth order diffracted light on the photodetector, and the optical information storage by the zeroth order diffracted light. The information accumulated on the medium is reproduced, and the information track on the optical information storage medium and the condensing spores of the zeroth order diffracted light are generated by diffraction light other than zeroth order. An optical head device for detecting in-plane misalignment with a laser beam, wherein a diffraction grating is provided on the first surface, and the pattern trace of the diffraction grating includes a beam firing point of the semiconductor laser and a firing point of the semiconductor laser. An optical pattern characterized in that the interference pattern is traced on the first surface by light waves having the same wavelength as that of the semiconductor laser emission light starting from a point light source disposed at each point in the plane perpendicular to the optical axis of the light. Head device. The optical head device according to claim 1, wherein the diffraction grating is a phase diffraction grating. The optical head device according to claim 1, wherein the diffraction grating is an amplitude type diffraction grating having a high and low reflectance. The optical head device according to claim 1, wherein the number of luminous fluxes separated in the luminous flux separation element is three. Astigmatism is imparted by the luminous flux reflected by the optical information storage medium passing through the first and second surfaces of the luminous flux separating element, and given a deformation for detecting the focus shift caused by the zero-order light. An optical head device according to claim 1, characterized in that. The optical head device of claim 5, wherein the first surface and the second surface of the luminous flux separating element are parallel to each other. The optical head device of claim 5, wherein the first and second surfaces of the luminous flux separating element have a wedge shape. The optical head device according to claim 4, wherein the diffracted light beam is focused on the disk as three light spots existing in the meridional plane with respect to the first plane of the light beam separation element. The optical head device according to claim 4, wherein the diffracted light beam is condensed on the disk as three light spots existing in the quadrilateral plane with respect to the first surface of the light beam separation element. The diffracted light beam is condensed on the disc as three light spots existing in the plane at an angle of 45 degrees about the optical axis in the meridional plane with respect to the first plane of the light beam separation element. Optical head device of claim 4 A semiconductor laser light source, a light beam splitting element diffraction-separated into several light beams of zero-order diffracted light and other diffracted light at the same time when reflecting the light beam emitted from the light source by the first plane, the light splitting element being reflected and separated by the light beam splitting element A condensing lens means for condensing the light flux as a plurality of light spots on the optical information storage medium, reflected by the information surface of the optical information storage medium, and retransmitted by the condensing lens means, thereby providing a first surface of the light beam separating element; It consists of a photodetector which receives the light beam transmitted through the second surface and photoelectrically changes, and detects the focal shift of the disk condensing light flux by the deformation of the zeroth order diffracted light on the photodetector, and the optical information by the zeroth order diffracted light. The information accumulated on the storage medium is reproduced, and the information track on the optical information storage medium and the condensing spores of the zeroth order diffracted light are generated by diffracted light other than zeroth order. An optical head device for detecting in-plane misalignment with a beam, wherein a diffraction grating is provided on the first surface, and the diffracted light beam exists in the meridional plane of the first surface of the light beam separation element. An optical head device, characterized in that the light is condensed on the disk as three light spots, and the pattern trace of the diffraction grating is a straight line in which the period changes linearly. ※ Note: The disclosure is based on the initial application.