Exposure control system for continuous tone electrophotographic film

Claim 1

A method for generating a dynamically corrected look-up table for modulating the intensity of actinic radiation incident on an imaging element comprising the steps of: (a) modulating the intensity of actinic radiation representative of an image having a predetermined number of variable optical density levels in accordance with a dynamically corrected look-up table; (b) exposing an imaging element to the modulation actinic radiation representative of the image; (c) modulating the intensity of the actinic radiation with information representative of a step wedge having a predetermined number of known optical denstiy levels using the dynamically corrected look-up table; (d) exposing the imaging element to the actinic radiation modulated by the step wedge information; (e) developing the image and step wedge on the imaging element; (f) comparing the optical density levels of the developed step wedge to the known optical density levels; (g) generating a correction signal based on the difference between the developed step wedge optical denstiy and the known optical density levels, and (h) correcting the look-up table in accordance with the correction signal.

Claim 2

A method for generating a dynamically corrected look-up table for modulating the intensity of actinic radiation incident on an imaging element comprising the steps of: (a) modulating the intensity of actinic radiation representative of an image having a predetermined number of variable optical density levels in accordance with a dynamically corrected look-up table; (b) exposing an imaging element to the modulation actinic radiation representative of the image; (c) modulating the intensity of the actinic radiation with information representative of a step wedge having a predetermined number of known optical denstiy levels using the dynamically corrected look-up table; (d) exposing the imaging element to the actinic radiation modulated by the step wedge information; (e) developing the image and step wedge on the imaging element; (f) comparing the optical density levels of the developed step wedge to the known optical density levels; (g) generating a correction signal based on the difference between the developed step wedge optical denstiy and the known optical density levels, and (h) correcting the look-up table in accordance with the correction signal.

Claim 6

An apparatus for producing a continuous tone toned electrophotographic image comprising: (a) means for transporting an imaging element along a predetermined path including first and second spaced positions; (b) a dispenser of imaging elements placed adjacent the transporting means surface to dispense one imaging element at a time from the dispenser onto the transporting means, the imaging element having an imaging surface thereon; (c) charging means located adjacent to the transporting means following the dispenser in the direction of motion of the tranporting means for establishing a uniform electrical charge on the surface of the imaging element; (d) means for producing a latent electrostatic image on the imaging surface; (e) toning means to apply an electrostatic toner on the latent electrostatic image on the imaging surface to render the latent image visible; and (f) means to permanently fix the toned image; (g) wherein the means for producing the latent electrostatic image itself comprises: means for storing a look-up table of exposure correction factors; means for measuring at the actual optical density of an image of a step wedge and generating a signal representative thereof; means for comparing the signal representative of the step wedge with a known set of optical density levels corrresponding to the step wedge to generate a set of correction values; means to apply the set of correction values to modify the look-up table of exposure correction factors thereby to form a dynamically corrected look-up table of such exposure correction factors useful to control the intensity of actinic radiation incident on an imaging element.

Claim 7

An apparatus for producing a continuous tone toned electrophotographic image comprising: (a) means for transporting an imaging element along a predetermined path including first and second spaced positions; (b) a dispenser of imaging elements placed adjacent the transporting means surface to dispense one imaging element at a time from the dispenser onto the transporting means, the imaging element having an imaging surface thereon; (c) charging means located adjacent to the transporting means following the dispenser in the direction of motion of the tranporting means for establishing a uniform electrical charge on the surface of the imaging element; (d) means for producing a latent electrostatic image on the imaging surface; (e) toning means to apply an electrostatic toner on the latent electrostatic image on the imaging surface to render the latent image visible; and (f) means to permanently fix the toned image; (g) wherein the means for producing the latent electrostatic image itself comprises: means for storing a look-up table of exposure correction factors; means for measuring at the actual optical density of an image of a step wedge and generating a signal representative thereof; means for comparing the signal representative of the step wedge with a known set of optical density levels corrresponding to the step wedge to generate a set of correction values; means to apply the set of correction values to modify the look-up table of exposure correction factors thereby to form a dynamically corrected look-up table of such exposure correction factors useful to control the intensity of actinic radiation incident on an imaging element.