KR960025433A - Beam Orthogonal Prisms for Optical Disc Recording Devices - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam shaping prism for an optical disk recording apparatus for shaping a beam in an optical pickup or information processing apparatus for playing and recording various reproducible and recordable optical disks such as an optical disk drive (ODD). The longer the optical path in the direction, the larger the size of the entire optical pickup, and thus, the difficulty in manufacturing and supporting the assembly of the optical parts and the assembly and adjustment of the optical parts. In the present invention, the problem of the conventional optical system in which the volume is increased is that the outgoing light is perpendicular to the initial incident optical axis while shaping the beam using the orthopedic prism 20 in which two prisms 20-1 and 20-2 having different refractive indices are bonded. The entire structure of the prism should be made of polygons with one side parallel to facilitate the assembly when machining the parts and assembling the mechanical parts. In addition, processing of parts and assembling of the optical system are easy, and the incident angles θ1 and θ3 are the Brewster angles, which do not cause a loss of light quantity, and the refractive index N2 of the second orthogonal prism 20-2 is appropriately selected. In addition to being able to adjust the magnification, it can be used without mirror coating during the total reflection of the beam, and in particular, the exit beam is perpendicular to the incident beam, thereby reducing the overall size of the optical pickup.

Description

Beam Orthogonal Prisms for Optical Disc Recording Devices

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

4 is a schematic diagram for designing an orthopedic prism of the present invention, and FIG. 5 is a schematic configuration diagram of an optical pickup using the present invention of FIG.

Claims (9)

In a beam shaping prism having a polyhedral structure for shaping a beam in a pickup optical system for an optical disk, the outgoing light is shaped while changing the intensity distribution of incident light whose intensity distribution in the vertical / horizontal direction is not constant to form a constant shape (circular shape). A beam shaping prism for an optical disc recording apparatus, characterized in that the entire structure of a pickup optical system for an optical disc is vertically / horizontally perpendicular to the first incident optical axis. 2. The beam incident prism according to claim 1, wherein the beam shaping prism is incident from the laser diode (1) and enters a first incident surface (a) that enters a beam converted into a parallel beam by the collector lens (2) at Brewster's angle (θ1). A first orthogonal prism 20-1 including a first emission surface b, which is refracted and exits at Brewster's angle θ3 again; A second incidence plane d, which is joined to the first exit plane b of the first orthogonal prism 20-1 and enters the beam at the Brewster angle θ3, and a total reflection plane e that totally reflects the incident beam; ) And a second orthogonal prism 20-2 including a second emission surface f for emitting the totally reflected beam to enlarge the diverging beam in the horizontal direction of the laser diode to perform beam shaping for the first incident light. A beam shaping prism for an optical disc recording apparatus, characterized in that the outgoing light is perpendicular. 3. The beam shaping prism according to claim 2, wherein the refractive index (N2) of the second shaping prism (20-2) is larger than that of the first shaping prism (20-1). 3. The beam shaping prism according to claim 2, wherein the second exit surface (f) is antireflective coated. 3. The method of claim 2, wherein the first emission surface b and the second entrance surface d are joined to each other by the refractive index N1 of the first orthogonal prism 20-1 or the second orthogonal prism 20-2. A beam shaping prism for an optical disc recording apparatus, characterized by bonding using an adhesive similar to the refractive index N2. 3. The method of claim 2, wherein the bottom surface (c) of the first orthogonal prism (20-1) and the second exit surface (f) of the second orthogonal prism (20-2) are made in parallel to facilitate assembly of the instrument. Beam shaping prism for optical disc recording apparatus characterized in that. 3. The optical disc of claim 2, wherein the first orthopedic prism 20-1 is a crown glass, and the second orthopedic prism 20-2 is a plant glass to remove chromatic aberration with respect to the wavelength change of the light source. Beam shaping prism for recording device. 3. The beam shaping prism according to claim 2, wherein the optical path of the light source incident on the shaping prism (20) is parallel with the optical path of the light source incident on the optical detector in the optical disk recording apparatus. The beam shaping method of claim 2, wherein the beam is incident on the second exit surface f of the orthopedic prism 20 and the beam is emitted to the first entrance surface a so that the diverging beam in the vertical direction is reduced. A beam shaping prism for an optical disc recording apparatus, characterized by this being made. ※ Note: The disclosure is based on the initial application.