Method for forming multiple images on a photographic film
US4497892A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1983 |
| Grant date | Feb 5, 1985 |
| Priority date | — |
| Expiry date | Jun 13, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G7/023
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for generating a negative or positive image from a single photographic medium. A source of radiant energy is projected onto a sheet of dielectric material heating the material to a polarizing temperature. A pair of electrical conductors are moved in a first direction along the surface of the heated dielectric material polarizing the material in the first direction. A photographic mask is then positioned over the polarized material and the radiant energy and the electrical field is again applied through the mask in a second direction to polarize certain portions of the material in the second direction. Projecting polarized light through the dielectric material and rotating the material during the projection produces a negative or positive image on the screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.