Color mixing and control system for use in an electrostatographic

Abstract

A system and method for color mixing control in an electrostatographic printing system. An operative mixture of colored developing material is continuously replenished with selectively variable amounts of developing materials of basic color components making up the operative mixture. The rate of replenishment of various color components added to the operative mixture is controlled to provide a mixture of developing material capable of producing a customer selectable color on an output copy substrate. A colorimeter is provided for monitoring the color of a test image printed with the operative mixture of developing material in the supply reservoir so that the color thereof can be brought into agreement with a color required to produce the customer selectable output color. The present invention can be used to control and maintain the color of the operational mixture of developing material in the reservoir through continuous monitoring and correction in order to maintain a specified ratio of color components in the reservoir over extended periods associated with very long print runs. The present invention may also be utilized to mix a customer selectable color in situ, whereby approximate amounts of primary color components are initially deposited and mixed in the developing material reservoir and resultant images printed with the developing material mixture are continually monitored and adjusted until the mixture reaches a desired color output.