Patent ID: 8446472
Filing Date: 2013-05-21
Classification: G02B,H04N

Abstract:
1. An imaging device which has an optical axis and which comprises a matrix IR detector, a multifocal lens with a focal length ranging from a short focal length to a long focal length, including a front group of lenses, a variator, a compensator and means of positioning the variator and the compensator, the positions of the variator and of the compensator being respectively adapted to the focal length, wherein the positioning means includes means of translating the variator and the compensator on the optical axis, wherein the imaging device comprises a calibration system which comprises a control for the means for positioning the variator in the vicinity of its short focal length position and the compensator upstream of its long focal length position so as to conjugate the plane of the detector with a real object plane located upstream of the front group of lenses a few centimeters from the latter, this positioning being called calibration positioning, and comprising, linked to the matrix detector, a processing unit which includes means for accumulating images obtained in calibration positioning mode.