Registration mark detection using matched filtering
US6739509B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2001 |
| Grant date | May 25, 2004 |
| Priority date | — |
| Expiry date | Mar 24, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system and method for detecting a registration mark associated with an object which provides improved resolution between matching and non-matching inputs. The registration mark represents a binary code sequence. Upon detecting a sequence of bits with a sensor, the detected sequence is provided to a code matching filter, which compares the detected sequence with the binary code sequence and produces a detection signal. The code matching filter increases a value of the detection signal for each matching pair of compared bits, and decreases the value of the detection signal for each non-matching pair of compared bits. In this manner, a penalty is assessed for mismatches. This results in a filter output having a high amplitude in response to a matching input, and a low amplitude for non-matching inputs. The system may sample the detected sequence of bits in such a manner as to avoid potential edge timing problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.