Appeal No. 95-2948
Application 07/833,664
Singh discloses a multi-faceted rotating mirror assembly aligned with a plurality of laser
output beams to produce a complex set of crossed pair lines as shown in figures 7 and 8 to reduce
the chance that a small bar code will not be read.
Figure 4 of Dvorkis teaches a two axis scanner. A U-shaped spring means 110 having a
pair of arms 112 and 114 has a scanning component, e.g., a mirror 116, mounted on arm 112 and
a permanent magnet 118 mounted on arm 114. An electromagnetic coil 120 is fixed on support
122 and vibrates the scanner through the magnet 118. Arm 114 and magnet 118 are secured to
a planar spring 128 mounted on a base. S-shaped leaf spring 134 and spring 142 are part of an
alternative embodiment (column 10, lines 12-21), which is not discussed. The coil is driven with
a signal that is the superposition of two driving signals, one being in a high frequency range,
typically about 200-800 Hz, and the other within a low frequency range, typically about 5-100 Hz.
"For example, a 500 Hz square wave signal may be utilized to oscillate component 116 in the x
direction and a 10 Hz sine wave signal may be utilized to oscillate component 116 in the y
direction" (column 8, lines 48-51). "Preferably, the high frequency signal is frequency tuned to
the resonant frequency of the U-shaped spring 110. Typically, the planar spring 128 will be driven
below its resonant frequency." Column 8, lines 55-58.
Figures 6a and 6b of Dvorkis show a scanner comprised of reflector 154 mounted to a
single planar spring 150 with its center of gravity 166 offset from axis 164 through the spring to
provide oscillatory movement in two orthogonal axes for a raster-type scan pattern. A magnet
156 is driven by coil 158 to vibrate the reflector. The coil is driven with a signal that is the
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Last modified: November 3, 2007