The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 2007
Filed:
May. 22, 2006
Kean Foong NG, Penang, MY;
Siang Leong Foo, Penang, MY;
Kean Foong Ng, Penang, MY;
Siang Leong Foo, Penang, MY;
Avago Technologies General IP (Singapore) Pte. Ltd., Singapore, SG;
Abstract
An interpolating detector for generating a position signal indicating a change in the relative position of a code pattern that includes alternating light and dark stripes is disclosed. The interpolating detector includes a photodiode array, an interpolation function generator, a detector function generator, and a cross-point detector. The photodiode array includes a plurality of sets of photodetectors that generate sinusoidal signals having different amplitudes and phases. The interpolation function generator generates first and second interpolation functions, I(x)=f1 cos(x) and I(x)=f2 sin(x), respectively, from the photodiode signals. The detector function generator generates 4 detector signals, D(x)-D(x), from the photodiode signals. The cross-point detector generates a transition signal when I(x) crosses Dor Dor when I(x) crosses Dor D. The photodiodes have active areas having a shape such that the x values at which the interpolation signals cross the detector signals occur at integer multiples of (2π/m) for a fixed m value.