Objective image double-tilt imaging optical system and design method thereof

The invention relates to an object image double-tilt imaging optical system and a design method thereof. And determining design parameters of an external structure of the imaging optical system and design parameters of each lens structure according to the imaging ranges of the object plane in the horizontal and vertical directions and the amplification factor of the system. The imaging optical system is of a double-telecentric structure and sequentially comprises a first free-form surface lens, a first spherical lens, a second free-form surface lens, a second spherical lens, a third free-form surface lens, a third spherical lens and a fourth free-form surface lens. The front surfaces and the rear surfaces of the three spherical lenses are spherical surfaces, the front surfaces and the rear surfaces of the first free-form surface lens, the second free-form surface lens and the fourth free-form surface lens are spherical surfaces and free-form surfaces, and the front surface and the rear surface of the third fr