Velocity Compensation For Drop On Demand Printers
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
It has been found that there is a relationship between drop velocity and drop volume in drop on demand ink jet printers. The drop volume is a linear function of the drop velocity. Drop size modulation is the key to gray scale printing techniques. Therefore, in order to print a quality gray scale, it is necessary to compensate for the velocity variations, assuming that the path of volume modulation is chosen. This article teaches the applicability of a known circuit technique to the solution of this compensation problem. Of course, the problem could also be solved in software, but the computations may prove burdensome, particularly in a fast printer with a large number of nozzles. The circuit concept proposed here is that embodied in U.S. Patent 4,158,204.