Method and apparatus for making multiple copies from an original

Claim 2

Apparatus for forming multiple images of each of a plurality of originals sequentially on a plurality of photosensitive surfaces at an exposure station, said apparatus comprising: means for successively forming an erasable, temporary image from each of the plurality of originals, said forming means including: a layered sandwich structure having in order, a first transparent electrode, a transparent photoconductive layer, a control layer which is substantially transparent in the absence of an electric field and scatters light under the influence of an electric field, and a second transparent electrode, means for applying a potential between said electrodes to create an electric field therebetween, and means for exposing said photoconductive layer through said first transparent electrode to each of said originals to render said photoconductive layer more conductive in exposed areas to increase the electric field across correspponding portions of said control layer to form said temporary image of the original on said control layer; activatable means for exposing sequentially each of a plurality of photosensitive surfaces to each temporary image to form a latent image; and means for erasing each temporary image after projection thereof onto each of said plurality of photosensitive surfaces.

Claim 3

Apparatus, as claimed in claim 1, further including: means for advancing said photosensitive surfaces seriatim into and out of the exposure station in response to termination of exposure of each said photosensitive surface in the exposure station.

Claim 4

Apparatus, as claimed in claim 2, further including: means for activating said exposing means in response to advancement of said photosensitive surfaces.

Claim 5

Apparatus, as claimed in claim 1, wherein said temporary image forming means includes: means for positioning each original to form each temporary image; and means for advancing said originals seriatim into and out of said positioning means in response to formation of a temporary image of an original in said positioning means.

Claim 6

Apparatus, as claimed in claim 1, wherein said control layer comprises: liquid crystal material.

Claim 7

Apparatus, as claimed in claim 1, further including: means for disabling said potential applying means after formation of a temporary image.

Claim 8

Apparatus for making multiple images sequentially on successive photosensitive surfaces in an exposure station from a temporary erasable image formed from a single exposure to an original, said apparatus comprising: a layered sandwich structure which includes in order: a first transparent electrode; a transparent photoconductive layer; a liquid crystal layer; and a second transparent electrode; a first source of potential for application across said electrodes at least during formation of said temporary image; means selectively operable to apply said first source of potential across said transparent electrodes at least during formation of said temporary erasable image; means for exposing said photoconductive layer to a radiation pattern corresponding to a first original for a predetermined exposure time when said first potential is applied across said electrodes to form a first temporary image on said liquid crystal layer; means for projecting radiation through said layered sandwich structure to expose a first photosensitive surface in the exposure station to said first temporary image to form a corresponding latent image on said first photosensitive surface; control means for enabling said operable means during exposure to said radiation pattern and responsive after a predetermined exposure time sequentially: to disable said means for projecting radiation to move an exposed photosensitive surface out of the exposure station and move an unexposed photosensitive surface intO the exposure station, and to enable said means for projecting radiation to expose said unexposed photosensitive surface to said first temporary image to form a corresponding latent image on said second photosensitive surface.

Claim 9

Apparatus for making multiple images sequentially on successive photosensitive surfaces in an exposure station from a temporary erasable image formed from a single exposure to an original, said apparatus comprising: a layered sandwich structure which includes in order: a first transparent electrode; a transparent photoconductive layer; a liquid crystal layer; and a second transparent electrode; a first source of potential for application across said electrodes at least during formation of said temporary image; means selectively operable to apply said first source of potential across said transparent electrodes at least during formation of said temporary erasable image; means for exposing said photoconductive layer to a radiation pattern corresponding to a first original for a predetermined exposure time when said first potential is applied across said electrodes to form a first temporary image on said liquid crystal layer; means for projecting radiation through said layered sandwich structure to expose a first photosensitive surface in the exposure station to said first temporary image to form a corresponding latent image on said first photosensitive surface; control means for enabling said operable means during exposure to said radiation pattern and responsive after a predetermined exposure time sequentially: to disable said means for projecting radiation to move an exposed photosensitive surface out of the exposure station and move an unexposed photosensitive surface intO the exposure station, and to enable said means for projecting radiation to expose said unexposed photosensitive surface to said first temporary image to form a corresponding latent image on said second photosensitive surface.

Claim 10

Apparatus, as claimed in claim 7, wherein said control means further includes: means to disable said operable means upon formation of said temporary image.

Claim 11

Apparatus, as claimed in claim 8, further including: a second source of potential for application across said electrodes to erase said temporary image; and wherein said operable means is also operable to apply said second source of potential across said electrodes, said control means further including: means to enable said operable means to apply said second potential across said electrods upon exposure of a predetermined number of photosensitive surfaces to said temporary image.

Claim 12

Apparatus, as claimed in claim 9, wherein: said first source of potential is a d.c. source, and said second source of potential is an a.c. source.

Claim 13

Apparatus as claimed in claim 7 further including: means responsive to exposure to said first temporary image for moving said first original out of said projection plane and for moving a second original into said projection plane.

Claim 14

Apparatus for making multiple copies sequentially on photosensitive material in an exposure station from an original which is removable during sequential exposure of the photosensitive material for replacement by another original from which one or more copies are to be made, said apparatus comprising: a layered sandwich structure that is capable of having a temporary image formed therein, which sandwich structure includes in order: a first transparent electrode; a transparent photoconductive layer; a liquid crystal layer; and a second transparent electrode; a first source of potential connectable across said electrodes; a switch operable to connect said electodes across said first potential source at least during formation of said temporary image; original advancing means for moving originals seriatim into and out of said projection plane; means for exposing said photoconductive layer to a radiation pattern of an original and for enabling said switch to apply said first potential across said electrodes at least during formation of the temporary image of the original in said liquid crystal layer; means for moving photosensitive material seriatim into and out of the exposure station; means for projecting radiation in response to formation of said temporary image through said sandwich structure to expose photosensitive material in the exposure station to said temporary image; means responsive to said radiation projecting means to enable said original advancing means to bring another original into said projection plane while said temporary image is being projected; means for enabling said photosensitive material moving means in response to exposure of the photosensitive material in the exposure station to move the exposed photosensitive material out of the exposure station and position unexposed photosensitive material in the exposure station; counting means having a first input for selecting the number of copies to be made from an original, and having a second input for receiving a count signal each time photosensitive material is exposed to a temporary image, said counting means providing a first signal until the selected number of copies have been made; and means for enabling said exposing means and for providing said count signal to said second input of said counting means in response to positioning of exposed photosensitive material in the exposure station and in response to said first signal from said counting means.

Claim 15

Apparatus for making multiple copies sequentially on photosensitive material in an exposure station from an original which is removable during sequential exposure of the photosensitive material for replacement by another original from which one or more copies are to be made, said apparatus comprising: a layered sandwich structure that is capable of having a temporary image formed therein, which sandwich structure includes in order: a first transparent electrode; a transparent photoconductive layer; a liquid crystal layer; and a second transparent electrode; a first source of potential connectable across said electrodes; a switch operable to connect said electodes across said first potential source at least during formation of said temporary image; original advancing means for moving originals seriatim into and out of said projection plane; means for exposing said photoconductive layer to a radiation pattern of an original and for enabling said switch to apply said first potential across said electrodes at least during formation of the temporary image of the original in said liquid crystal layer; means for moving photosensitive material seriatim into and out of the exposure station; means for projecting radiation in response to formation of said temporary image through said sandwich structure to expose photosensitive material in the exposure station to said temporary image; means responsive to said radiation projecting means to enable said original advancing means to bring another original into said projection plane while said temporary image is being projected; means for enabling said photosensitive material moving means in response to exposure of the photosensitive material in the exposure station to move the exposed photosensitive material out of the exposure station and position unexposed photosensitive material in the exposure station; counting means having a first input for selecting the number of copies to be made from an original, and having a second input for receiving a count signal each time photosensitive material is exposed to a temporary image, said counting means providing a first signal until the selected number of copies have been made; and means for enabling said exposing means and for providing said count signal to said second input of said counting means in response to positioning of exposed photosensitive material in the exposure station and in response to said first signal from said counting means.

Claim 16

Apparatus, as claimed in claim 12, wherein said liquid crystal layer is a mixture of nematic and cholesteric material having a memory and said counting means provides a second signal when the sElected number of copies have been made, said apparatus further including: a second source of potential connectable across said electrodes to erase said temporary image; means responsive to said second signal from said counting means to enable said switch to connect said electrodes across said second potential source to erase the temporary image in said liquid crystal layer.

Claim 17

In an electrophotographic apparatus which includes a photoconductive member movable along an endless path past a plurality of stations spaced along said path, said plurality of stations including: a charging station for placing a generally uniform electrostatic charge on said photoconductive member; an exposure station for exposing a charged portion of said photoconductive member to a pattern of radiation derived from an original to form an electrostatic latent image; a developing station for developing said electrostatic latent image to form a toner image; a transfer station to transfer the toner image to a receiver; and a cleaning station for removing residual toner particles from said photoconductive member, and activatable means for moving said photoconductive member along said endless path, the improvement in said exposure station comprising: a layered sandwich structure which includes in order: a first transparent electrode; a photoconductive layer; a liquid crystal layer; and a second transparent electrode; means for applying a first potential between said electrodes; means for exposing said photoconductive layer to a radiation pattern for a predetermined exposure time while said first potential is applied across said electrodes to render exposured areas of said photoconductive layer more conductive than unexposed areas thereof to form a first temporary image on said liquid crystal layer; means for projecting radiation through said layered sandwich structure to exposure a first charged portion of said photoconductive member in said exposure station to said first temporary image to form a corresponding electrostatic latent image on said first charged portion; control means responsive after a predetermined exposure time sequentially to disable said means for projecting said radiation within said second portion of the electromagnetic specturm, to activate said means for moving said photoconductive member to move the exposed portion from the exposure station to the developing station and to move a second charged portion from the charging station to the exposure station, and to enable said means for projecting radiation to expose said second charged portion of said photoconductive member to said first temporary image to form a corresponding electrostatic latent image on said second charged portion of said photoconductive member.

Claim 18

In an electrophotographic apparatus which includes a photoconductive member movable along an endless path past a plurality of stations spaced along said path, said plurality of stations including: a charging station for placing a generally uniform electrostatic charge on said photoconductive member; an exposure station for exposing a charged portion of said photoconductive member to a pattern of radiation derived from an original to form an electrostatic latent image; a developing station for developing said electrostatic latent image to form a toner image; a transfer station to transfer the toner image to a receiver; and a cleaning station for removing residual toner particles from said photoconductive member, and activatable means for moving said photoconductive member along said endless path, the improvement in said exposure station comprising: a layered sandwich structure which includes in order: a first transparent electrode; a photoconductive layer; a liquid crystal layer; and a second transparent electrode; means for applying a first potential between said electrodes; means for exposing said photoconductive layer to a radiation pattern for a predetermined exposure time while said first potential is applied across said electrodes to render exposured areas of said photoconductive layer more conductive than unexposed areas thereof to form a first temporary image on said liquid crystal layer; means for projecting radiation through said layered sandwich structure to exposure a first charged portion of said photoconductive member in said exposure station to said first temporary image to form a corresponding electrostatic latent image on said first charged portion; control means responsive after a predetermined exposure time sequentially to disable said means for projecting said radiation within said second portion of the electromagnetic specturm, to activate said means for moving said photoconductive member to move the exposed portion from the exposure station to the developing station and to move a second charged portion from the charging station to the exposure station, and to enable said means for projecting radiation to expose said second charged portion of said photoconductive member to said first temporary image to form a corresponding electrostatic latent image on said second charged portion of said photoconductive member.

Claim 19

The improvement, as claimed in claim 14, further including: means for applying a second source of potential across said electrodes for erasing said temporary image after a predetermined number of exposures of successive portions of said photoconductive member.