Patent ID: 8366001
Filing Date: 2013-02-05
Classification: A61B,G02B,G03B

Abstract:
1. A method for calibration in the field of an open loop variable focus imaging system, said imaging system comprising a sensor, a lens arrangement with an electrically controlled focal length optical device for adjusting the focus as a function of a distance measurement of an object to be imaged, a driver for applying a predetermined electrical signal to the electrically controlled optical device, said signal being related to the measured distance by a function comprising pre-recorded parameters, the method comprising: for at least two distances, determining for each distance the value of the electrical signal to be applied to get a best image contrast measurement of the object to be imaged positioned at said distance; and updating the pre-recorded parameters of the function between the electrical signal to be applied and the measured distance using the values associated with the at least two distances.