Patent ID: 7163275

Claim:
An apparatus for controlling operation of at least one fluid ejector, the apparatus comprising: at least one light emitting device that emits a light beam substantially perpendicular to a fluid ejector path; at least one light detector positioned to receive the light beam from the at least one light emitting device and to provide an output indicative of receipt of the light beam; and a control device including: a selection section that selects a set of at least one fluid ejector to be tested, an operating property determining section that determines an operating property of said at least one fluid ejector based on a detection signal of said at least one light detector, a compensation determining section that determines a preferred method from a plurality of methods of compensating problems associated with the at least one fluid ejector to restore the at least one fluid ejector towards an optimal performance level for use of said at least one fluid ejector during subsequent operation based on the operating property of said at least one fluid ejector determined by said operating property determining section, and a modification determining section that applies the preferred method of compensating said at least one fluid ejector determined by said compensation determining section for said at least one fluid ejector to control subsequent operation of said at least one fluid ejector.