Browse Prior Art Database

Optical Head

IP.com Disclosure Number: IPCOM000114557D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Hamahata, K: AUTHOR [+2]

Abstract

Disclosed is an Optical system of Optical memory disc. This Optical system is constructed by a Multi function prism that has three reflecting surfaces as symmetrical structure with one Optical block. This Optical block can be made in one glass block with thin file coating. This method is to simplify the Optical system of Optical memory disc.

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Optical Head

      Disclosed is an Optical system of Optical memory disc.  This
Optical system is constructed by a Multi function prism that has
three reflecting surfaces as symmetrical structure with one Optical
block.  This Optical block can be made in one glass block with thin
file coating.  This method is to simplify the Optical system of
Optical memory disc.

      The Figure shows the example of this system.  The Multifunction
prism has three surfaces, that is, (2),(5), and (6) surfaces.  These
surfaces are facets of an integral optical trapezoidal block.  This
optical block is called Multifuction prism.

      The read-out light from LD(1) goes to Optical block surface(2).
The light is effected by this surface(2) as Beam shaped as circular
and the Beam is split in two paths.  One path is directed to the
Disk(3) and the other path is to AUX detector(4).  The beam goes to
Disk(3) and is reflected to surface(5).  This surface(5) is a perfect
reflecting surface, capable of reflecting almost 100% beam to
surface(6).  The surface(6) is a beam split surface the property of
which is same as surface(2).  The beam is then split in two paths,
one path is going to servo detector path(7) and the other path is
going to RF signal detector path(8).  Therefore, this Multifunction
prism fascilitates constructing Optical system of Optical memory and
its symmetrical architecture allows fabricating the optical system at
a low cost.

      The Multifunction opt...