Optical scanner system approaches are described in which novel focusing approaches
are provided. A control algorithm accounts for geometric variation of successive
scans in opposite directions across a microarray slide or substrate in order to
provide optimized focus. The feedback approach taught may involve PI or PID terms.
In either type of control approach, a projected slope of the slide is calculated
and followed back and forth outside a scan region of the array in exiting and entering
fully adaptive focusing zones, respectively. During turn-around, the system may
track a setpoint between the periods of following the extrapolated slope. Also
provided are methods of using the subject system in a biopolymer array based application,
including genomic and proteomic applications.
