Patent ID: 6633024
Filing Date: 2003-10-14
Classification: G02B,G03F

Abstract:
An apparatus, comprising:an autofocus system for automatically focusing each of a plurality of scan lines produced by an imaging system on a supply of recording material, the autofocus system including: a control loop with scan line to scan line feedforward of a motor command waveform, wherein the autofocus system adds a final motor command waveform of a previous scan line to a motor command waveform of a current scan line to produce a final motor command waveform for the current scan line; and a motor for controlling the imaging system to focus each of the plurality of scan lines on the recording material, wherein the motor focuses the current scan line on the recording media in response to the final motor command waveform of the current scan line; wherein the autofocus system determines a focus error of the current scan line by subtracting a focus position of the imaging system, as set by the motor in response to the final motor command waveform of the previous scan line, from a surface position of the recording media for the current scan line.