Composite optical parts and optical sensor using the composite optical parts

Abstract

A composite optical part, is a translucent body allowing transmission of a laser beam through its interior is provided with a first entrance plane part 14a entered by a first laser beam L1, a second entrance plane part 14b entered by a second laser beam L2, an entrance / emission plane part 14c entered at predetermined angles of incidence by the first and second light beams respectively emitted from the first and second entrance plane parts 14a and 14b, emitting them outside, and entered by each returned light of the light beams, and an emission plane part 14d emitting the returned light entering from the entrance / emission plane part 14c. In the entrance / emission plane part 14c, a diffraction grating 16 is provided correcting a difference in the angles of incidence to the entrance / emission plane part 14c of the first and second laser beams guided to the same position on the entrance / emission plane part 14c and matching optical axes after emission from the entrance / emission plane part 14c. The diffraction grating 16 causes each returned light to transmit through the entrance / emission plane part 14c and emit from the emission plane part 14d in a state with the matched optical axes.

Description

technical field [0001] The present invention relates to an optical sensor using lasers of different wavelengths, in particular to a dual-purpose optical sensor for CD and DVD using lasers of two wavelengths and a composite optical component used for the optical sensor. Background technique [0002] In recent years, optical disc devices have been able to inject lasers of different wavelengths onto each non-interchangeable optical disc such as CD and DVD, and can read the reflected light from the optical disc surface and reproduce the recorded information recorded on the optical disc surface. [0003] In order to be able to read and reproduce the recorded information written on these different optical discs using a single optical disc device, for example, two wavelengths corresponding to a laser diode in the 780 nm band for CD and a laser diode in the 635 nm band for DVD are used. light sensor. [0004] As shown in FIG. 6 , the conventional optical sensor 100 for CD and DVD i...

AI Technical Summary

Problems solved by technology

[0014] However, in the conventional optical sensor 100, there is a problem that since both the holographic laser 102 for CD and the holographic laser 112 for DVD include holographic elements 106, 116, expensive holographic elements 106, 116 and including their holographic lasers, therefore, it is difficult to reduce the cost

[0015] Moreover, there is also the following problem: that is, in order to constitute an optical sensor corresponding to such different wavelength lasers, when assembling these optical components such as the holographic laser 102 for CD and the holographic laser 112 for DVD, it is necessary to ensure that the mounting positions do not misalign. make the job more difficult and complicated

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