Alignment method
US5703685A · kind A · utility
38Cited by
8References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1995 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Jul 20, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An alignment method is provided for determining a mark position by using any of a first method for determining a mark position with one of photodiodes for colors which shows a maximal contrast between a mark area and a non-mark area, a second method for determining a mark position by detecting mark positions with photodiodes for colors and taking an average for these positions and a third method for determining a mark position by determining a ratio for determining that mark position, through the photodiodes for colors, by using different contrast levels between a mark area and a non-mark area and a CCD color area sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.