The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 1995
Filed:
Oct. 04, 1993
Gene F Day, Hillsborough, CA (US);
Phoenix Precision Graphics, Inc., Sunnyvale, CA (US);
Abstract
A method and apparatus for a continuous developing system for electrostatic printing in which a mixing means is disposed within a tank containing developer concentrate in order to maintain the concentrate in an homogenous solution. This mixing allows a concentration of dissolved charge agent in the concentrate to be greatly reduced, as the higher concentration of charge agent is no longer needed to prevent toner particles within the concentration from agglomerating. The lower concentration of charge agent facilitated by the concentrate mixing allows the concentrate to have a charge agent concentration as low as that favorable for the developing solution. The concentrate can therefore be combined with a carrier liquid to form a developer immediately before printing, rather than using premixed developer. The concentrate and the carrier can also be added continuously to replenish developer lost to printing without increasing the charge agent concentration in the developer to a point where the developer must be discarded. A purifier may be used in direct process printing to remove ionic contaminants, concentrate and carrier being added to replenish developer lost to purification, thereby avoiding the build up of contaminants in the developer which can also necessitate discard of the developer. The periodic discard and replacement of volumes of developer is avoided, being replaced with small additions of concentrate and discard of small chunks of waste.