Eastman-Kodak Company

Pierce B Day

David E Hockey

George N Tsilibes

John P Swapceinski

Tomas Roztocil

Carl M Marsiglio

John L Steeves

Dale Smith

An electrophotographic reproduction apparatus and method are provided for reproducing an original document sheet that includes a continuous tone pictorial information area and a line-type information area. Rather than reproducing the entire document sheet with screening of both types of information, means are provided for selectively screening only the pictorial information area on the reproduction. The means of one preferred embodiment comprises a programmable illumination source that is programmed through inputs by the operator using a digitizing tablet to selectively image portions of a screen onto a charged photoconductive web prior to development of the electrostatic image formed on the web so that only the area on the web receiving the pictorial image is exposed to the screen. In another embodiment the programmable illumination source, such as LED's, modulates the portion of the image frame receiving an optical exposure of the pictorial information with the screen type exposure so that the pictorial information only is reproduced with a screen pattern. In still another embodiment a sensor automatically senses and determines the image portions to be selectively screened.

Electrophotographic reproduction apparatus and method with selective

A duplicator has a movable photoconductor on which electrostatic images are formed. A rotatable transparent cylinder positioned adjacent the front side of the photoconductor has a screen pattern thereon. Wheels on the cylinder contact the photoconductor so that the cylinder is rotated in response to movement of the photoconductor. An elongate light shield positioned inside the cylinder has a first slot adjacent the portion of the cylinder near the photoconductor, and a Fresnel lens is positioned in the slot. Light rays from a point source located outside the cylinder pass through a second slot in the shield and are reflected from a mirror inside the cylinder onto the Fresnel lens. The lens collimates the light rays and directs them through the screen on the transparent drum to thereby project onto the photoconductor an image of the screen pattern on the cylinder.

Apparatus for projecting a screen pattern onto a photoconductor

A duplicator has a photoconductor on which electrostatic images are formed. A member having a screen pattern of opaque and transparent areas is positioned adjacent to the photoconductor. A Fresnel lens near the screen member receives light rays from a concentrated light source spaced from the lens. Means are provided for folding light rays from the source a plurality of times and then directing the light rays onto the lens, thereby to provide collimated light rays that are directed onto the member to provide an image of the screen pattern onto the photoconductor. The light rays can be folded by means of a polygon of glass or other suitable materials, or by two parallel mirrors and a plurality of baffles arranged so that the light rays are reflected repeatedly from one mirror surface to the other. By folding the light rays a plurality of times, the distance traveled by light rays from the light source to the Fresnel lens can be equal to the focal length of the Fresnel lens and, at the same time, the projection apparatus can be quite small or compact.

Compact screen projector

An apparatus in which latent image charge patterns on image-receiving members, corresponding respectively to related primary color separation images of multicolor input information, are developed with pigmented marking particles to form transferable images. Two of the latent image charge patterns are simultaneously produced on discrete areas of the image-receiving members respectively. A third latent image charge pattern is produced on a discrete area of one of the image-receiving members adjacent to one of the aforementioned discrete areas. The developed images of the two simultaneously produced latent image charge patterns are transferred to a receiver member in superimposed register, with a substantial portion of the transfers occurring simultaneously. The developed image of the third charge pattern is subsequently transferred in superimposed register with the previously transferred patterns to produce the multicolor reproduction.

Color reproduction apparatus

Compact optical imaging apparatus for projecting in focus an upright and wrong-reading light image of an information bearing document in an object plane onto a parallel image plane. The apparatus comprises a plurality of lenses located between the object plane and the image plane for projecting a plurality of overlapping segments of a light image along an optical path. A light image of an information bearing document in the object plane is directed to the lenses. A plurality of roof mirrors (i) receive such image segments from the lenses, (ii) reverse and invert such image segments, and (iii) reflect the image segments back through the lenses along the path toward the image plane. The image segments are then directed from the lenses to the image plane to form an upright and wrong-reading image of the information bearing document in the image plane.

Compact optical imaging apparatus

A simplified optical arrangement for an electrophotographic copier for making multicolor reproductions of a multicolor original document. The copier includes at least one charged photoconductive member which is exposed by primary color separation images of an original document to form corresponding latent image charge patterns. The primary color separation images are projected onto the photoconductive member by the simplified optical arrangement which includes a catadioptric lens assembly optically located between the original document and the photoconductive member. The lens assembly includes relatively tilted dichroic mirrors spectrally sensitive respectively to the primary colors to separate an image of an original document into primary color separation images, and project such images respectively in straight line optical paths toward distinct spacial locations on the photoconductive member.

Color electrophotographic copier

A document drum and a transparent drum are mounted on a common shaft. The two drums are coaxial with each other and with the shaft. An optical system is provided for forming an image of a slit-like rectangular area of a document mounted on the external surface of the document drum onto a similar slit-like imaging area on the imaging drum. The optical system comprises a first mirror for reflecting light rays from the document drum to a lens, and second and third mirrors for reflecting light rays from the lens through the transparent drum. The optical axis of the lens is tilted relative to the light paths of the first mirror and the second mirror so that the light rays can be directed around the shaft.

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Pittsford, NY, United States of America

Pierce B Day