Browse Prior Art Database

Optical Head Design for Minimization of Dust Contamination

IP.com Disclosure Number: IPCOM000121772D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Phan, H: AUTHOR [+3]

Abstract

The photograph, Figure 1, was taken of the top surface of the optical head of a CD-ROM drive following a dust test. It was noticed that the brush, attached to the standard cleaning disc, appears to sweep dust particles, which have fallen on the head surface, into the aperture and down into the optics. The original purpose of the cleaning brush was simply to remove dust particles from the lens.

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Optical Head Design for Minimization of Dust Contamination

      The photograph, Figure 1, was taken of the top surface of
the optical head of a CD-ROM drive following a dust test. It was
noticed that the brush, attached to the standard cleaning disc,
appears to sweep dust particles, which have fallen on the head
surface, into the aperture and down into the optics. The original
purpose of the cleaning brush was simply to remove dust particles
from the lens.

      A raised bead was designed on the head top surface to act as a
"plow" and help prevent dust from being pushed into the aperture. The
unique design of this bead can be seen by referring to Figure 2.
Since a boundary layer of air adheres to the spinning optical disc,
the aerodynamic design of the bead makes use of this airflow to
create an area of lower pressure over the opening. This lower
pressure area also helps keep dust particles from falling into the
optics.

      This modification has been shown to improve resistance to
contamination for open optical heads. A factorial experiment was
constructed to evaluate this, as well as several other possible
improvements. The bead design was found to be a significant factor
for extending life in a dusty environment.