Browse Prior Art Database

Miniature Rotary Optical Actuator

IP.com Disclosure Number: IPCOM000115625D
Original Publication Date: 1995-Jun-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 55K

Publishing Venue

IBM

Related People

Bargerhuff, RA: AUTHOR [+2]

Abstract

Disclosed is a device for use as a rotary optical actuator. Its simple design allows it to be easily produced at a very small size while providing long life, no wear, minimal play, and minimal heating of the optical payload. This is accomplished by combining a flexural pivot suspension with a rotating magnet voice coil motor (VCM).

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Miniature Rotary Optical Actuator

      Disclosed is a device for use as a rotary optical actuator.
Its simple design allows it to be easily produced at a very small
size while providing long life, no wear, minimal play, and minimal
heating of the optical payload.  This is accomplished by combining a
flexural pivot suspension with a rotating magnet voice coil motor
(VCM).

      The rotary VCM consists of a ring-shaped permanent magnet that
has been magnetized as shown in Fig. 1, a magnetic flux return path,
and two coils.  The return path acts as both a structural member for
the assembly, and as a heatsink for the VCM coils.  This latter
feature permits more electric current to be delivered to the VCM
coils, resulting in greater VCM torque.  Also, by using a moving
magnet design the optical payload experiences minimal heating.

      The flexural pivot permits rotation through a limited arc,
while providing high stiffness in the other degrees of freedom.  By
not having any wear contact surfaces and minimal play, a flexural
pivot may provide unlimited life.  One embodiment of a flexural pivot
is shown in Fig. 2.  This type of flexural pivot would have one of
its flat springs anchored to the return path while the opposite end
of the second flat spring would be anchored to either the optical
payload or permanent magnet.  Flexural pivots may be purchased as a
subassembly, such as the Lucas* Free-Flex* shown used in an actuator
assembly in Fig. 1.

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