Uniform exposure of photosensitive medium by square intensity profiles for printing
US6011631A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 29, 1997 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Jan 29, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In classic optical rendering systems, the spot, illuminating a microdot on the photosensitive medium, is designed to overlap with neighboring microdots, typically having an overlap of 1.7 times the pitch of the microdots, for a luminous intensity of 1/e.sup.2 the highest intensity. A "sharp" photosensitive medium, such as a photographic film used in graphical applications, generates a binary circle, obtainable by thresholding. The area of such a circle is too large, which results in higher dot gain. Many systems, such as electrographic systems, do not behave as a "sharp" medium. If intermediate energy levels are used, in order to obtain continuous tone or multiple density levels, thresholding behavior may be avoided by appropriate choice of energy levels. Such a different sensitometry results in specific requirements for the energy distribution for each microdot. A square shaped uniform energy distribution within the space allotted to each microdot, allows for multiple density levels, without severe sensitometric requirements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.