Light blocking stop for electro-optic line printers
US4724467A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1983 |
| Grant date | Feb 9, 1988 |
| Priority date | — |
| Expiry date | Apr 11, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/315
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The stop for the Schlieren imaging optics which are used in an electro-optic line printer to image a multigate light valve onto a photosensitive recording medium has smoothly tapered sides to reduce crosstalk between the pixels of the image. As a result, the transmittance of the imaging aperture, as viewed along the modulation axis of the printer, rolls off relatively gradually and more or less continuously along the edges of the stop, thereby reducing the high angle diffraction off the stop so that the troublesome sidelobes of the coherent amplitude point spread function of the imaging system are suppressed. The stop preferably is in the shape of a parallelogram selected to substantially attenuate either the zero order or the higher order diffraction components of the phase front modulated light beam exiting from the light valve so that the intensity profile of the remaining or unattenuated light has the required image characteristics. Variations in the basic parallelogram shape wherein the stop sides have specially curved configurations to optimize triangular, cosine, and Gaussian light amplitude transmittance profiles are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.