Basic optical unit of optical disc playing device

Abstract

The basic optical unit of CD player consists of the first laser diode, the second laser diode and optical path compensating plate, and can simplify the structure of double light beam pick-up. The first laser diode emits the first laser beam in the direction of light waveguide axis; the second laser diode emits the second laser beam in the wavelength different from that of the first laser beam and in the direction deviating from the light waveguide axis; and the optical path compensating plate forms grating and makes the laser beam the second laser diode emits converted to the direction of light waveguide axis. The basic optical unit of present invention is formed through lamination and this facilitates the batch manufacture and reduces the size and weight. Therefore, the present invention is suitable for use in portable instrument.

Description

(1) Technical field [0001] The present invention relates to the basic optical unit of the optical disc playing equipment, especially refers to the optical path compensating plate which makes the light emitted by the two laser diodes consistent with the axis of the optical waveguide, and can be used in small and thin optical disc playing equipment. A basic optical unit of an optical disc playback device that plays more than one medium on an optical disc playback device. (2) Background technology [0002] In general, recently, optical pickup devices intended to interchangeably play optical discs having mutually different recording densities have also been developed in various forms. [0003] figure 1 It is a conceptual diagram of a conventional optical pickup device that can play back using different media depending on the thickness of the disc. [0004] As shown in the figure, the existing optical pick-up device is made up of the following parts: the first laser diode 11 of...

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Problems solved by technology

This leads to the problem that the amount of light utilized in partial reflection and transmission is low, making the light efficiency significantly low

[0015] In order to solve such a problem, even if one beam splitter is used, Patent Application No. 1998-0025783 (Korea) proposes to use a dual pickup that scatters two laser diodes of different wavelengths, but the two laser diodes are set as Positioned opposite to each other, and the beam splitter is formed with a selective reflective surface for oblique separation and vertical arrangement, therefore, there is a problem that it is not suitable for small and thin optical disc playback equipment

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