TY - JOUR
AU - Kou-Fan, Chin
AB - The astigmatic off-focus detection is one of the commonly used automatic focusing techniques. Generally, the astigmatism is introduced by means of cylindrical lens.Take the optical disc autofocusing system as an example0), the light spot on the detector, which normally is circular, will suffer elliptical deformation if the information plane of the disc changes its distance from the objective (see Fig.1). The amounts of light impinging on the four quadrants are no longer equal and a difference signal can be derived
TI - Optimization Design Of An Astigmatic Focusing System
JF - Proceedings of SPIE
DO - 10.1117/12.967327
DA - 1987-01-01
UR - https://www.deepdyve.com/lp/spie/optimization-design-of-an-astigmatic-focusing-system-H3D45ZXePx
SP - 421
EP - 422
VL - 813
IS - 
DP - DeepDyve
ER -