Patent ID: 6609781
Filing Date: 2003-08-26
Classification: B41J,H03L

Abstract:
A printhead firing control system for an inkjet printer, comprising:a printhead mounted for movement across a paper path; an encoder for producing a digital output signal indicative of movement of the printhead; a filter circuit connected to receive the digital output signal for filtering the digital output signal to remove frequency variations which meet at least one predetermined parameter, the filter circuit providing a filtered digital signal; and a fire-pulse generation circuit connected to receive the filtered digital signal from the filter circuit and producing printhead heater resistor drive pulses based at least in part upon the filtered digital signal; and wherein the predetermined parameter comprises exceeding a threshold frequency variation level; wherein the printhead is mounted to a carriage which is driven by a belt, and the threshold frequency variation level is below a frequency of belt disturbances affecting the digital output signal.