Projection screen and apparatus for the fabrication thereof
US3977766A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1975 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Apr 24, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T83/7145
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection screen of improved aesthetic quality. The screen comprises a plurality of rectilinear rows of precisely contoured optical microelements each adapted to redistribute substantially all of the incident image flux through a predefined audience angle with uniform luminance. The microelements are formed in a surface of a work piece by applying an electrical signal of predefined waveform but of random frequency to the input of the cutting stylus of a sound recording head which moves relative to the work piece in a series of parallel traverses. The electrical signal is recorded on a memory element which moves with the work piece past a stationary pickup head as each row is cut. Because the same signal from the memory element is used to cut each row, an identical phase relationship is maintained between the microelements in adjacent rows.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.