Toner Concentration Control
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
The toner concentration within the magnetic brush developer of a xerographic copier or printer is changed by a key operator by means of a control key which operates to change the development electrode bias voltage on the developer rolls, but only during the concentration network's test patch cycle. This control key is interlocked so that it is available only to the key operator, as by the use of a number code which must be entered by use of the copier's copy number keys. As a result, the key operator may set the copy density as desired, leaving it to each individual user thereafter to select the copy contrast as desired, by the use of the copier's lighter-copy and darker-copy keys. The toner concentration patch sensing means to be used can be the one described in U. S. Patent 4,466,731.