IMAGING OPTICAL SYSTEM
Imaging optical system comprising an objective with a compensation plate and an imaging sensor, wherein the objective is arranged to image objects which are arranged in an object plane in an image plane, a distance from the object plane to the objective is adjustable, the image sensor is arranged to capture the image in the image plane, a thickness of the compensation plate along the optical axis of the objective is adjustable, and the thickness depends on the distance.
1 . Imaging optical system comprising an objective with a compensation plate and an imaging sensor, wherein
the objective is arranged to image objects which are arranged in an object plane in an image plane,
a distance from the object plane to the objective is adjustable,
the image sensor is arranged to capture the image in the image plane,
a thickness of the compensation plate along the optical axis of the objective is adjustable, and
the thickness depends on the distance.
2 . Imaging optical system according to claim 1 , the compensation plate comprising a first window element, a second window element and a liquid chamber between the first and the second window element, wherein
the liquid chamber is filled with a liquid having a refractive index larger than air,
the first window element and the second window element are movable with respect to each other, and
the thickness of the compensation plate is adjustable by altering the geometry of the liquid chamber.
3 . Imaging optical system according to claim 1 , wherein the objective comprises a lens, wherein the compensation plate is arranged between the lens and the image sensor along the optical axis of the objective.
4 . Imaging optical system according to claim 1 , wherein the first window element comprises an optical filter which is arranged to absorb and/or reflect electromagnetic radiation in the wavelength range of infrared radiation.
5 . Imaging optical system according to claim 1 , wherein the lens forms the second window element, and the imaging optical system is arranged to adjust the distance of the object plane to the objective and the thickness of the compensation plate by moving the lens with respect to the image sensor.
6 . Imaging optical system according to claim 1 , wherein
the first window element forms a first refractive surface and the second window element forms a second refractive surface,
a shape of the first refractive surface and/or a shape of the second refractive surface is static, and
the first window element and/or the second window element are at least one of:
a flat transparent plate,
a rigid lens,
a rigid prism.
7 . Imaging optical system according to claim 1 , wherein the first window element and/or the second window element is moveable in a direction perpendicular to the optical axis of the objective.
8 . Imaging optical system according to claim 7 , wherein
the objective is arranged to perform optical image stabilization by movement of the first window element with respect to the second window element in a direction perpendicular to the optical axis of the objective and/or
the objective is arranged to perform super resolution imaging by movement of the first window element with respect to the second window element in a direction perpendicular to the optical axis of the objective.
9 . Imaging optical system according to claim 1 , the lens comprising a tunable optical element, wherein the optical power of the tunable optical element is adjustable, and the distance of the object plane to the objective is adjusted by adjusting the optical power of the tunable optical element.
10 . Imaging optical system according to claim 9 , wherein the tunable optical element comprises:
a lens volume which is filled with a lens liquid,
a lens membrane which delimits the lens volume on one side, and
a shaping element which is movable with respect to the lens volume, wherein
the lens membrane forms a refractive surface of the tunable optical element, and the optical power of the tunable optical element is adjustable by changing a curvature of the lens membrane by means of moving the shaping element with respect to the lens volume.
11 . Imaging optical system according to claim 10 , comprising an actuator, which is arranged to generate an actuation force, wherein the actuation force results in a movement of the shaping element with respect to the lens volume and in a movement of the first window element with respect to the second window element.
12 . Imaging optical system according to claim 11 , wherein
the compensation plate comprises the tunable optical component, wherein the liquid volume comprises the lens volume,
the first window element comprises the lens membrane.
13 . Imaging optical system according to claim 12 , wherein
the objective is arranged to increase the thickness of the compensation plate when the optical power of the tunable optical component is increased and vice versa, and
the change in thickness of the compensation plate along the optical axis is larger than the change in thickness required to change the shape of the lens membrane for adjusting the optical power of the objective.
14 . Imaging optical system according to claim 1 , the compensation plate comprising a wall which limits the liquid chamber in directions perpendicular with respect to the optical axis circumferentially.