Highlight color imaging apparatus.

摘要

Tri-level highlight color imaging apparatus and cleaner apparatus therefor. Improved cleaning of a charge retentive surface is accomplished through matching the triboelectric properties of the positive and negative toners (TONER B and TONER A) and their associated carriers (CARRIER B and CARRIER A) as well as the carrier used in the magnetic brush cleaner apparatus. The carrier in the cleaner upon interaction with the two toners causes them both to charge to the same polarity. The carrier used in the cleaner is identical to the one used in the positive developer (CARRIER B). The carrier (CARRIER A) of the negative developer was chosen so that the toner (TONER A) mixed therewith charged negatively in the developer housing. Thus, the combination of toners and carriers is such that one of the toners (TONER B) charges positively against both carriers (CARRIER A and CARRIER B) and the other of the toners (TONER A) charges negatively against one of the carriers (CARRIER A) and positively against the other (CARRIER B). Due to the application of a positive pretransfer corona both the toners are positive when they reach the cleaner housing and because the carrier employed in the cleaner causes both of the toners to charge positively, toner polarity reversal is precluded.