Abstract:
An electrographic stylus recording apparatus producing a toner powder image on a receptor belt wherein non-imaging toner powder is collected at a cylindrical sleeve located downstream from the stylus array and is subsequently returned from the cylindrical sleeve to the upstream side of the stylus array by depositing toner powder from the cylindrical sleeve onto the receptor belt by adjustment of the toner powder on the cylindrical sleeve relative to the space between the cylindrical sleeve plus the application of a d.c. voltage to the cylindrical sleeve.
Abstract:
A recording member comprising a conductive substrate having a dielectric coating thereon. The recording member is particularly useful with the electrographic recording process and apparatus described in U.S. Pat. No. 3,816,840. The dielectric coating contains a charge build-up inhibitor to allow the recording member to be used for a large number of cycles of image-formation and image-removal with virtually no build-up of charge or deterioration of image quality, and the surface of the coating is sufficiently durable to allow the recording member to be used repeatedly before the recording member needs to be replaced.
Abstract:
Electrographic stylus recording apparatus for producing a magnetically attractable toner powder image on a receptor belt including two rotatable cylindrical sleeves, each having a non-rotatable magnetic roll, with one sleeve positioned adjacent the upstream side of a stylus array and the other sleeve adjacent the downstream side with each of such sleeves adapted for connection to a d.c. source, the upstream sleeve being connected to a d.c. source to place toner powder on the receptor belt for delivery of toner powder to the stylus array when a toner image is to be made and the downstream sleeve being connected to a d.c. source to place toner powder on the receptor belt from such sleeve for return to the upstream side of the stylus array via the receptor belt. The magnet rolls within the sleeves are positioned to provide like magnetic poles to the stylus array to provide a magnetic flux at the recording ends of the styli in the array. Each of the magnetic rolls also provide a magnetic pole to the receptor belt at the point where the sleeves are closest to the receptor belt.
Abstract:
A method for operating an electrophotographic proofing system for generating color proofs from image information during multiple imaging cycle proofing runs. Charge model information, development model information and toner replenishment model information are stored for each component color. Actual photoconductor charge characteristics are measured during the imaging cycles of the proofing runs. Actual toner characteristics from component color test patches developed during the imaging cycles are also measured. The photoconductor is charged during the imaging cycles as a function of the charge characteristics measured during a preceding imaging cycle for the same component color, and a as function of the charge model information for the color. The photoconductor is toned during imaging cycles as a function of toner characteristics measured from test patches during a preceding imaging cycle for the same component color and as a function of the development model information for the color. Working toner is replenished after the imaging cycles as a function of the development parameters used to tone the photoconductor during the imaging cycles for the same component color and as a function of the replenishment model information for the color. Charge model information and the development model information for each component color are updated as a function of measured values after the imaging cycles.
Abstract:
A calibration procedure for an electrophotographic proofing system of the type for generating color proofs during multiple image cycle proofing runs from imaging information representative of half-tone color patterns for each of a set of colors by sequentially, during the imaging cycle for each color of the set, charging a photoconductor as a function of a charge model representative of photoconductor contrast voltages as a function of a charging grid voltage, modulating a laser as a function of the color pattern information to expose the photoconductor, and toning the exposed photoconductor as a function of a development model representative of measured developed toner color densities as a function of development voltage. The calibration procedure generates charge and development models for each color of the set during one proofing run, and includes: i) charging a plurality of first color test patches on the photoconductor, each with a different known grid voltage from a range of grid voltages; ii) exposing the first color test patches on the photoconductor; iii) measuring the contrast voltages of the photoconductor at the first color test patches; iv) toning the first color test patches as a function of known development voltages; v) measuring the of the toner at the first color test patches; vi) repeating steps i-v for each remaining color of the set during one proofing run; vii) generating a charge model, for each color of the set, representative of the measured contrast voltages as a function of the associated grid voltages; and viii) generating a development model, for each color of set, representative of the measured toner densities as a function of the associated development voltages.