Browse Prior Art Database

High-Performance, Low-Cost Optical File Actuator

IP.com Disclosure Number: IPCOM000119178D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 90K

Publishing Venue

IBM

Related People

Luecke, F: AUTHOR

Abstract

Disclosed is a high-performance, low cost optical file actuator.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

High-Performance, Low-Cost Optical File Actuator

      Disclosed is a high-performance, low cost optical file
actuator.

      Fig. 1 shows an actuator assembly.  Optics assembly (A) is
pivotably mounted to base (B) by means of spheres (C1 and C2) in
sockets in the optics assembly and base.  Spheres and sockets can be
made of various compatible materials, such as stainless steel balls
and Teflon  or Delrin sockets.  Tubular arm (D) is attached to optics
assembly (A)  by means of compliant member (E), of a material chosen
to provide for some relative motion of the tip of the arm in tracking
and focus directions.  The compliant material chosen must also
provide damping to eliminate detrimental resonances of the arm tip at
fundamental frequencies determined by the inertias of the optics
assembly and the arm, and by the stiffness of the compliant member.
Tubular arm (D) is made of a high stiffness-to-density ratio
material, such as a graphite-epoxy composite, to minimize high
frequency resonances.  Objective lens (D1) and mirror (D2) comprise
the "payload"  of the arm, which must move to keep the lens in focus
and on track on disk (F).

      Coil assembly (G) is attached to the end of the arm and
provides the forces required to move the arm tip.  Coil (G1) provides
force in the tracking direction, and coils (G2) and (G3) (in series)
provide force in the focus direction, when current is supplied to the
respective coils.  Pole pieces (H1), (H2), and (H3) and permanent
magnet (J), all fastened to base (B), provide the magnetic flux field
in which coil assembly (G) operates, constituting a moving coil
actuator.  The radius of the arm and the distance from the a...