Light modulation element and light modulation apparatus
US4842396A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1985 |
| Grant date | Jun 27, 1989 |
| Priority date | — |
| Expiry date | Jun 26, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/0248
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light modulation element of the invention has a plurality of polygonal modulation portions for modulating incident light staggered on arrays. Sides, of each two adjacent portions on different arrays, which are closest to each other are parallel to each other and are not perpendicular to the array direction. The modulation portions can be arranged at a high density along the array direction, the utilization efficiency of illumination light is improved, and the modulation light amount can be increased. When an element is used for a recording apparatus, and S/N ratio is improved, uniform exposure along the array direction is achieved, and the required memory capacity is decreased. A light modulation apparatus of the invention has an imaging optical system, a modulation optical system, and a scanning optical system. By incorporating a suitable means in an optical system or changing the optical system arrangement, a separation angle between modulated and non-modulated lights is increased, and diffracted light generated due to a shape of a light modulation element as a component of the apparatus can be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.