Screened optical system

Claim 2

An optical system including: a light source positioned to illuminate an original document with light rays; a lens in a light receiving relationship with the light rays transmitted from the original document to form a light image thereof; a plurality of screen members; a belt member having each of said screen members mounted thereon in a spaced relationship with one another; means for movably supporting said belt member; means for moving said belt member to position a pre-selected one of said screen members in the optical light path in a light receiving relationship with the light image transmitted from said lens with the other of said screen members being spaced from the optical light path; a substantially opaque belt member having a plurality of spaced slits therein, each of the slits decreasing the intensity of the light image inwardly from the marginal regions to the central region thereof; means for movably supporting said opaque belt member; and means for moving said opaque belt member to position a pre-selected one of said slits in the optical light path in a light receiving relationship with the light image transmitted from said lens with the other slits therein being spaced from the optical light path.

Claim 3

A system as recited in claim 1, further including means for filtering the light image to form a substantially single color light image.

Claim 4

A system as recited in claim 2, wherein each of said plurality of said screen members include a plurality of substantially equally spaced lines.

Claim 5

A system as recited in claim 3, wherein each of said plurality of screen members include differing numbers of equally spaced lines.

Claim 6

An electrophotographic printing machine, including: a photoconductive member; means for charging said photoconductive member to a substantially uniform level; exposure means for creating a light image of an original document and projecting the light image onto the charged portion of said photoconductive member recording an electrostatic latent image thereon, said exposure means comprising a light source positioned to illuminate the original document with light rays, a lens in a light receiving relationship with the light rays transmitted from the original document to form a light image thereof, a plurality of screen members, a belt member having each of the screen members mounted thereon in a spaced relationship with one another, means for movably supporting the belt member, and means for moving the belt member to position a pre-selected one of the screen members in the optical light path in a light receiving relationship with the light image transmitted from the lens with the other of the screen members being spaced from the optical light path; a substantially opaque belt member having a plurality of spaced slits therein, each of the slits decreasing the intensity of the light image inwardly from the marginal regions to the central region thereof; means for movably supporting said opaque belt member; and means for moving said opaque belt member to position a pre-selected one of said slits in the optical light path in a light receiving relationship with the light image transmitted from the lens of said exposure means with the other slits therein being spaced from the optical light path.

Claim 7

An electrophotographic printing machine, including: a photoconductive member; means for charging said photoconductive member to a substantially uniform level; exposure means for creating a light image of an original document and projecting the light image onto the charged portion of said photoconductive member recording an electrostatic latent image thereon, said exposure means comprising a light source positioned to illuminate the original document with light rays, a lens in a light receiving relationship with the light rays transmitted from the original document to form a light image thereof, a plurality of screen members, a belt member having each of the screen members mounted thereon in a spaced relationship with one another, means for movably supporting the belt member, and means for moving the belt member to position a pre-selected one of the screen members in the optical light path in a light receiving relationship with the light image transmitted from the lens with the other of the screen members being spaced from the optical light path; a substantially opaque belt member having a plurality of spaced slits therein, each of the slits decreasing the intensity of the light image inwardly from the marginal regions to the central region thereof; means for movably supporting said opaque belt member; and means for moving said opaque belt member to position a pre-selected one of said slits in the optical light path in a light receiving relationship with the light image transmitted from the lens of said exposure means with the other slits therein being spaced from the optical light path.

Claim 8

A printing machine as recited in claim 5, further including: means for developing the electrostatic latent image recorded on said photoconductive member with toner particles; means for transferring the developed powder image from said photoconductive member to a sheet of support material; and means for affixing substantially permanently the toner powder image to the sheet of support material.

Claim 9

A printing machine as recited in claim 6, wherein said exposure means includes means for filtering the light image to form a substantially single color light image.

Claim 10

A printing machine as recited in claim 7, wherein the plurality of screen members of said exposure means include a plurality of substantially equally spaced lines.

Claim 11

A printing machine as recited in claim 8 wherein each of the plurality of screen members of said exposure means include differing numbers of equally spaced lines.