Spatial light modulator exposure unit and method of operation

An exposure unit for use in a printing system, said printing system having a reproductive unit for accepting light images from said exposure unit, said images comprising a plurality of individual bits each controlled by an off/on data signal, said exposure unit having first and second ends and a base and comprising:

• a housing adjacent said first end for accepting a light bulb;
• a support adjacent said second end for accepting a spatial light modulator array positioned away from and facing said light source such that unmodulated illumination from said source will fall on pixels of said array, said array being substantially flat, and when in said supports project upward from said base to hold the edges of said array, said array being positioned slightly from the perpendicular to said base so as to create an optical axis for light reflected by said array pixels slightly downward with respect to said base;
• a focusing element support for accepting a focusing element adopted for controlling the image formed by light reflected by modulated ones of said pixels;
• and
• a sloping indention in said base in the shape of a bee thorax and extending along said optical axis, said indention positioned between said focusing element support and said array support, the tapering end of said thorax facing said array, said thorax adapted to include said focusing element support for accepting light selectively reflected from modulated pixels and for communicating said reflected light to said reproductive unit while rejecting all light reflected from unmodulated pixels or from inactive areas of a said array mounted in said support.

The method of constructing an optical exposure unit for use in a reproductive system having both an exposure portion and a reproductive portion, said reproductive portion operative in response to presentation of modulated light patterns for representing said modulated patterns as image on a transfer medium, and method comprising the steps of:

• positioning a light source at one end thereof;
• disposing a support opposite said light source or holding an array of spatial light modulator elements, said elements individually controllable for modulating light to form said modulated patterns;
• mounting at least one lens in said unit between said light source and said support;
• mounting an imager lens in said unit between said light modular array and said contact reproduction portion;
• interposing a light baffle system between said array and said image lens for eliminating from said imager lens off-state light reflected from said array portions not a part of said modulated pattern as well as from nonselected ones of said modulator elements;
• and
• presenting, via an exit aperture and steering mirrors in the base of said unit, said modulated patterns accepted by said imager lens to said contact reproductive process.

The method of operating an exposure unit for use in a printing system, said printing system having a reproductive unit for accepting images from said exposure unit, said images comprising a plurality of individual bits each controlled by an off/on data signal, said exposure unit having first and second ends and a base and said method comprising the steps of:

• positioning a light bulb in a housing adjacent said first end of said unit;
• positioning a support adjacent said second end for accepting a spatial light modulator array positioned away from and facing said light source such that unmodulated illumination from said source will fall on pixels of said array, said array being substantially flat, and when in said supports project upward from said base to hold the edges of said array, said array being positioned slightly from the perpendicular to said base so as to create an optical axis for light reflected by said array pixels slightly downward with respect to said base;
• accepting a focusing element adopted for controlling the image formed by light reflected by modulated ones of said pixels;
• and
• expending a sloping indention in said base in the shape of a bee thorax along said optical axis, said indention positioned between said focusing element support and said array support, the tapering end of said thorax facing said array, said thorax adapted to include said focusing element support for accepting light selectively reflected from modulated pixels and for communicating said reflected light to said reproductive unit while rejecting all light reflected from unmodulated pixels or from inactive areas of a said array mounted in said support.