Spatially selective optical system

Claim 2

An optical system including: means for supporting an original document; a light source in communication with said supporting means for illuminating the original document positioned on said supporting means, said light source comprising at least red, blue and green phosphors with the blue/green ratio being 0.3 and the red/green ratio being 0.53; lens means for receiving the light rays transmitted from the original document to form a light image thereof; means for filtering the light image to produce a single color light image; and a normally transparent photochromic filter interposed in the path of the single color light image, said photochromic, filter responsive to the intensity of the single color light image, darkening to automatically regulate the intensity of the single color light image transmitted therethrough and returning to the normally transparent condition when the single color light image is not being transmitted therethrough.

Claim 3

A system as recited in claim 1, wherein said photochromic filter attenuates the high intensity light rays transmitted through said filtering means to a greater extent than the low intensity light rays transmitted therethrough.

Claim 4

A system as recited in claim 2, wherein said photochromic filter includes borosilicate glass having silver halide crystals therein.

Claim 5

A system as recited in claim 1, wherein said filtering means includes: a blue filter interposed into the light image path to transmit a blue light image therethrough; a green filter interposed into the light image path to transmit a green light image therethrough; and a red filter interposed into the light image image to transmit a red light imaage therethrough.

Claim 6

An electrophotographic printing machine of the type having a photoconductive surface, including: means for charging the photoconductive surface; means for creating a light image of an original document; means for filtering the light image to produce a single color light image; and a normally transparent photochromic filter interposed between the photoconductive surface and said filtering means in the path of the single color light image, said photochromic filter, responsive to the intensity of the single color light image, darkening to automatically regulate the intensity of the single color light image transmitted therethrough for irradiating the charged photoconductive surface to selectively dissipate the charge thereon in accordance with the intensity of the single color light image passing through said photochromic filter, said photochromic filter attenuating the high intensity light rays transmitted through said filtering means to a greater extent than the low intensity light rays transmitted therethrough and returning to the normally transparent condition when the single color light image is not being transmitted therethrough.

Claim 7

An electrophotographic printing machine of the type having a photoconductive surface, including: means for charging the photoconductive surface; means for creating a light image of an original document; means for filtering the light image to produce a single color light image; and a normally transparent photochromic filter interposed between the photoconductive surface and said filtering means in the path of the single color light image, said photochromic filter, responsive to the intensity of the single color light image, darkening to automatically regulate the intensity of the single color light image transmitted therethrough for irradiating the charged photoconductive surface to selectively dissipate the charge thereon in accordance with the intensity of the single color light image passing through said photochromic filter, said photochromic filter attenuating the high intensity light rays transmitted through said filtering means to a greater extent than the low intensity light rays transmitted therethrough and returning to the normally transparent condition when the single color light image is not being transmitted therethrough.

Claim 8

A printing maching as recited in claim 5, wherein said photochromic filter includes borosilicate glass having silver halide crystals therein.

Claim 9

A printing machine as recited in claim 5 wherein said light image creating means includes: a light source for illuminating the original document; and lens means for receiving the light rays from the original document to form a light image thereof.

Claim 10

A printing machine as recited in claim 7, wherein said light source includes at least red, blue, and green phosphors with the blue/green ratio being 0.3 and the red/green ratio being 0.53.

Claim 11

A printing machine as recited in claim 8 wherein said filtering means includes: a blue filter interposed into the light image path to transmit a blue light image therethrough; a green filter interposed into the light image path to transmit a green light image therethrough; and a red filter interposed into the light image path to transmit a red light image therethrough.