Patent ID: 6084627
Filing Date: 2000-07-04
Classification: H04N

Abstract:
An apparatus for controlling an image recording device having a light source for producing a beam of light and an acousto-optic deflector for deflecting the beam of light so as to write a sub-scan comprising a predetermined number of picture elements, the image recording device being arranged to write a plurality of sub-scans side by side in a substantially contiguous manner, said apparatus comprising sub-scan commencing means for commencing a sub-scan, a start of sub-scan detector for detecting when the light beam is directed towards a start of sub-scan position, an end of sub-scan detector for detecting when the beam of light is directed towards an end of sub-scan position, a timing logic controller for generating a start reference signal representing a desired position for the start of a sub-scan, and a control arrangement for comparing an output of the start of sub-scan detector with respect to the start reference signal and for adjusting a frequency range of a chirp applied to said acousto-optic deflector while keeping a start time of the chirp constant so as to cause an arrival time of the light beam at the start of sub-scan detector to coincide with the start reference signal, and picture element rate controller for adjusting a rate at which picture elements are written such that a final one of the picture elements is written a predetermined period before the light beam is directed towards the end of sub-scan position.