Patent ID: 8687165
Filing Date: 2014-04-01
Classification: G02F

Abstract:
1. A variable focal length imaging system for imaging an object onto an image sensor, wherein the imaging system comprises: a) a front side facing the object; b) a rear side facing away from the object, said rear side being arranged behind the front side as viewed from the object; c) a light entrance device at the front side through which light coming from the object can enter into the imaging system; d) at least one first and one second optical element which are arranged at the rear side in such a way that they can influence the focal length of the beam path within the imaging system; and d1) an image sensor upon which light from the object passing through the entrance device and along the beam path is imaged; characterized e) in that the light entrance device has an electrically switchable liquid crystal element for selectively deflecting the beam path at at least one first angle and a second angle which is different from the at least one first angle, depending on the electrical switching state; f) wherein the selected beam path impinges on the first optical element at the rear side at the at least one first angle, or on the second optical element at the rear side at the second angle; g1) wherein when the beam path impinges on the first optical element at the rear side of the imaging system at the at least one first angle, at least a first focal length of the imaging system is obtained, and g2) wherein when the beam path impinges on the second optical element at the rear side of the imaging system at the second angle, a second focal length different from the at least one first focal length of the imaging system is obtained.