A LOW-COST AUTOMATIC TRANSLATION AND AUTOFOCUSING SYSTEM FOR A MICROSCOPE

In this design note we describe a low-cost system for scanning the tra nslation stage and automatically maintaining the correct focal positio n of a microscope. The image signal is derived from a video camera and the focal position determined by measuring the energy in the edge-det ected image. The microscope is a conventional laboratory microscope wi th stepping motors attached to actuate the stage and control is effect ed through a laboratory personal computer. The system components (with the exception of the personal computer) cost a few hundred USA dollar s.