Patent ID: 9148165
Filing Date: 2015-09-29
Classification: G01D,G06F,H03M

Abstract:
1. A pattern wheel driver comprising: a rotatable pattern wheel with patterned regions repeatedly formed on the pattern wheel, each of the patterned regions having a plurality of patterns, wherein each pattern of the plurality of patterns has a different width; only a single photodiode configured to detect the plurality of patterns, the single photodiode mounted at a position where the patterned regions of the pattern wheel pass when the pattern wheel rotates; and an encoder configured to produce a signal indicating whether the pattern wheel rotates in a forward direction or a reverse direction based on signals produced by the only a single photodiode, wherein each of the patterned regions has at least one of at least three reflective sections with differing widths or at least three non-reflective sections with differing widths.