Exposure apparatus
US5062692A · kind A · utility
9Cited by
18References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1990 |
| Grant date | Nov 5, 1991 |
| Priority date | — |
| Expiry date | Nov 21, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/0082
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure apparatus for use in fabricating a printed circuit board. A thermally-written liquid-crystal light valve is provided in which a pattern is formed by opaque portions and transparent portions. A writing optical system directs a heating spot light onto the light valve. The light valve and/or the heating spot light is movable, relative to the other. A projecting optical system is arranged which transmits a luminous flux emitted from a light source, through a liquid-crystal layer within the liquid-crystal light valve. The projecting optical system illuminates a subject with the transmitted luminous flux.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.