Monitoring scan mirror motion in electro-optical readers and image projectors

• Main Author: WOOD FREDERICK F
• Format: Patent
• Language: Chinese; English
• Published: 21.07.2010
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; BASIC ELECTRIC ELEMENTS; CINEMATOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DEVICES USING STIMULATED EMISSION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC SWITCHES; ELECTRICITY; ELECTROGRAPHY; EMERGENCY PROTECTIVE DEVICES; FREQUENCY-CHANGING; HOLOGRAPHY; INDUCTANCES; MAGNETS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHOTOGRAPHY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; RELAYS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SELECTORS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TESTING; TRANSFORMERS

The present invention discloses a crosstalk between a drive coil and a primary feedback coil is eliminated by positioning a secondary feedback coil in proximity with the drive coil for contamination by the crosstalk to the same extent as the primary feedback coil, and by processing feedback signals generated by the feedback coils to cancel the crosstalk. The drive coil is used to oscillate a scanmirror employed in an image projection arrangement or an electro-optical reader.