Optical pickup apparatus

Abstract

An optical pickup device for recording, reproducing or erasing information on an optical disc (500) is provided, comprising: a semiconductor laser element (100) integrated with at least two light sources; and a holographic optical element (200) with A plurality of emission areas where each light emitted from the semiconductor laser element (100) is divided into a plurality of emission areas by reflected light on the optical disc (500). The hologram optical element (200) has dividing lines (201 to 203) for dividing emission regions at positions intersecting the optical axis of the reflected light. This optical pickup device detects signals corresponding to light beams that are roughly equally divided into two when any one of the plurality of light sources is in operation.

Description

technical field [0001] The present invention relates to an optical pickup device for recording, reproducing, or erasing information on an optical medium such as an optical disk or an optical card, or a magneto-optical medium. Background technique [0002] As a high-density and large-capacity recording medium, optical discs are used not only for music, but also for storing and distributing images and various data. They are utilized in various fields, and their market demand is rapidly expanding. [0003] In such an optical disc device, the part responsible for reading information from the optical disc or recording information on the optical disc is an optical pickup device. This optical pick-up device generally comprises: the semiconductor laser element as light source, the condensing optical system that condenses the light beam from the semiconductor laser element on the optical disc, and a part of the light beam that is reflected on the optical disc and passes through the o...

AI Technical Summary

Problems solved by technology

[0010] However, these plurality of light sources are arranged in the direction in which the two divisions are performed, that is, in the direction perpendicular to the track columns of the optical disc. figure 1 As shown, the optical axes of the light beams emitted from multiple light sources and the reflected light are different in the optical system with each light source. Therefore, it is difficult to obtain an ideal 2-divided signal with a simple 2-divided optical element.

Ideal division can only be achieved by dividing at the intersection point of the optical axes of multiple reflected lights. However, there are cases where the intersection point is located in the lens, or the intersection point is moved by the tracking operation of the objective lens using the focus servo, so It is physically impossible to implement a mechanism that implements a stable binary division

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