Eastman-Kodak Company

Michael D Stoudt

Eric Karl Zeise

Michael Wilfred Mosehauer

Jerome G Spitzner, Deceased

Fereidoon S Jamzadeh

George N Tsilibes

Jerome G Spitzner

David Q McDowell

The specification discloses apparatus by which multiple reproductions can be produced from an original, all reproductions from the same original being of substantially identical quality. An electrographic machine substantially uniformly charges an electrographic recording member to a predetermined initial voltage and imagewise exposes the charged recording member at a nominal exposure level to produce a latent charge image. The initial voltage level and the exposure level are process control parameters of the machine, which also includes a biased electrode for controlling deposition of toner to the latent charge image. Signals are produced and stored having values characteristic of (1) the level of at least one of the parameters and (2) the bias voltage level which are associated with a desired reproduction quality of an original. A comparison signal is produced by taking the signal values of the sensed parameters associated with latent charge images of successive reproductions of an original and comparing them with the stored signal values for the corresponding latent charge images of the same original. The bias voltage level associated with the latent charge image is varied in response to the comparison signal, thereby producing a developed image having substantially the same upright quality as that produced by the stored signal values.

Dynamic feedforward process control for electrographic machines

Apparatus and method for electrophotographically producing high quality reproductions which contain different content types. Photoconductor image sectors are subjected to separate optical exposures selected for (1) good tone-scale reproduction of continuous-tone image portions and (2) high-contrast reproduction of line-type image portions. Photoconductor background area, which border continuous-tone image portions, are discharged to a level below the system's development level. Color line-art from a black and white original is also provided for in a color-copier by exposing a separate original containing a swatch of the color to be reproduced on the same image frames exposed to the image of the line-art. A digitizing tablet is used in combination with a selective erase means to provide selective screening and/or spot color effects. The digitizing tablet may be incorporated to use the exposure platen and may be of the sonic type or other types not employing grid lines visible to the photoconductor.

Apparatus and method for electrophotographically producing copies from

A multicolor electrophotographic reproduction apparatus and method are provided for reproducing a copy in a selected colors. The apparatus includes a digitizer for inputting information denoting the location(s) of the pictorial information and the location(s) for which selected coloration is desired. The respective colors desired for reproduction of the information may be chosen from a menu of twenty-five or more colors stored in memory. In addition to an exposure source for reproducing an image of the original upon a photoconductor the apparatus also includes an illumination source for selective erase and a second illumination source which illuminates the photoconductor through a halftone screen to control the charge level on areas of a color separation image frame in accordance with the color selected to thereby effect the color which a reproduction will have.

Multicolor electrophotographic reproduction apparatus and method for

Method and apparatus for electrophotographically producing high quality reproductions which contain different content types. Photoconductor image sectors are subjected to separate, component exposures selected for (1) good tone-scale reproduction of continuous-tone image portions and (2) high-contrast reproduction of line-type image portions. Photoconductor background areas, which border continuous-tone image portions, are exposed to a discharge level below the system's development level.

Apparatus and method for electrophotographically producing copy having

A plurality of constituent electrostatic color-separation images are produced in sequence for subsequent toner-development and superimposition and at least one developed constituent image is used to color-correct a succeeding constituent image which is not yet developed. Apparatus and method embodiments described herein utilize light which is diffusely-reflected from toner on a developed photoconductor image sector to expose in register, and thus color-correct, an undeveloped electrostatic image on another photoconductor sector. Such auxiliary 'scatter-masking' exposures can be predeterminedly or selectively adjusted in tone scale.

Apparatus and method for forming multicolor electrophotographic images

The duplex copying of two-sided originals onto two sides of a copy sheet is accomplished by interspersing images from two successive documents on a multi-image imaging member, specifically with the front-side image of a second document interspersed between the front and rear-side images of a first document. Copy sheet turnover can thus occur during the transfer of the front-side of the second document to achieve an increased 'copy-output-rate to electrographic-procedure-speed' ratio.

Growing community of inventors

Webster, NY, United States of America

Michael D Stoudt