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Reduction of Noise And Vibrations in the High-Speed Scanner

IP.com Disclosure Number: IPCOM000121059D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 4 page(s) / 121K

Publishing Venue

IBM

Related People

Gowda, JC: AUTHOR

Abstract

The rigid scanner spindle is of a cantilever design where the mirror and balance wheel are mounted on the free end, outside the bearings, for easier manufacturing and assembly. As the frequency of the rigid scanner spindle increases, the requirements on the spindle and the bearings supporting the wheel and hub-mirror cap become increasingly stringent. Microscopic mechanical defects in the bearing races, balls, component placements and dynamic balancing inaccuracies can cause higher noise levels and beam vibrations.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Reduction of Noise And Vibrations in the High-Speed Scanner

      The rigid scanner spindle is of a cantilever design where
the mirror and balance wheel are mounted on the free end, outside the
bearings, for easier manufacturing and assembly. As the frequency of
the rigid scanner spindle increases, the requirements on the spindle
and the bearings supporting the wheel and hub-mirror cap become
increasingly stringent. Microscopic mechanical defects in the bearing
races, balls, component placements and dynamic balancing inaccuracies
can cause higher noise levels and beam vibrations.

      Depending on the frequency of these disturbances, the scanned
laser beam may not run straight across a photoconductive drum.  The
Continued result, therefore, is a transferred image that is visibly
faded on paper.

      This article investigates the reduction of noise/vibration at
the resonant peak-frequency by minimizing the mass, increasing the
inertia, and optimizing the balancing operation time and parts cost.
Also, it shows that the unique, grooved-diecast cap can be used as a
mirror-cap and balance wheel for further noise reduction, without
increasing the power consumption.

      These changes meet the acceptance criteria of a sound power
level of 6.2 bels or less, and a static or dynamic balancing of the
spindle and balance wheel under 0.5 gm.mm in each plane at, or below,
16,000 rpm.  It is important for the sound power level of the scanner
not to increase one bel before reaching 15,000 hours of its operating
time period.
CALCULATED RESULTS OF THE SYSTEM'S RESIDUAL TORQUES AT MODAL
FREQUENCIES
(a)...