Exposure control method and apparatus compensating for detection of offset from a measured value
US5053614A · kind A · utility
30Cited by
3References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1990 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | Oct 2, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2001/444
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An exposure apparatus includes a pulsed light source for repeatedly emitting a pulsed light; a photoelectric converting device for receiving at least a portion of the pulsed light from the pulsed light source; and a control device for controlling the emission of the pulsed light source, on the basis of a value related to a difference between a photoelectric signal produced from the photoelectric converting device at the time of emission of the pulsed light and an offset signal produced from the photoelectric converting device at the time of non-emission of the pulsed light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.