A VARIABLE ILLUMINATION OPTICAL SYSTEM
Original Publication Date: 1977-Jun-30
Included in the Prior Art Database: 2004-Mar-30
Xerox Disclosure Journal
An electrophotographic printing machine optical system em-ploying a screen to modulate the light produced thereby. The intensity of the light image is varied as a function of screen position. Screen 28 is disposed closely adjacent to photo-conductive surface 12 of drum 10. Drum 10 rotates in the direction of arrow 14. Screen 28 is mounted slideably in rail 74. Rack 76 is secured integral to screen 28. Worm gear 28 meshes with rack 76. Rotation of worm gear 78 translates rack 76. Translation of rack 76 moves screen 28 relative to photo-conductive surface 12 to adjust the spacing therebetween. As screen member 28 moves, the intensity of the light image transmitted therethrough is suitably adjusted. This is achieved by regulating the intensity of the light rays gen-erated by lamps 26, Thus, for any position of screen 28, there is an optimum light ray intensity.