Low profile optical head

Abstract

An optical head of the type usable in an optical disc reader / writer is provided. The optical head has a low profile, eg less than about 5 mm, preferably less than about 3 mm in a vertical direction parallel to the axis of rotation of the disc. Practically all components of the optical system, including laser light source, objective lens, participating optical components and photodetectors, are provided in the optical head and mounted in fixed positions relative to each other. Virtually all components of the optical head move as a unit, eg during tracking and / or focusing. Preferably, the optical head is fabricated using large scale wafer and / or stacking techniques, eg stacking substantially planar components to achieve the final optical head structure.

Description

[0001] This application is a continuation-in-part of Patent Application Serial No. 09 / 457,104 (Attorney Docket No. 4154-9), filed December 7, 1999, which is hereby incorporated by reference. Cross reference to: U.S. Patent Application Serial No. 09 / 315,398, filed May 20, 1999, entitled "Removable Optical Storage Device and System," also identified as Attorney Docket 4154-1 , and entitled "Combination Mastered and Writeable Medium and Use in Electronic BookInternet," also identified as Proxy Document 4154-2-PROV, issued in 1999 U.S. Patent Application No. 60 / 140,633, filed June 23. technical field [0002] The present invention relates to an optical head, such as for reading and writing optical discs, and more particularly, to an optical head in which all optical components, from the laser light source to the objective lens, maintain a substantially fixed spatial relationship. Background technique [0003] An important factor affecting the design of an optical system, such a...

AI Technical Summary

Problems solved by technology

Providing a low vertical profile can be particularly cumbersome because, at least in some optical designs (including, for example, certain conjugate designs) a minimum optical path is required or recommended (although the read / write beams will generally be normal to the plane where the disc is located)

Images