Prism-Based Focal Plane Adjustment for Thermal Compensation in a Lens Assembly

摘要

To compensate for a focal plane shifting away from an image plane due to a temperature change, an integrated image sensor and lens assembly includes an optical component and an optics compensator including passively actuating elements. The passively actuating elements couple the optical component to the inner surface of the lens mount. The passively actuating elements and the optics component are configured such that the focal plane is maintained to coincide with or substantially coincide with the image plane. The passively actuating elements and the optics component adjust the distance an incident ray travels in the optics compensator when the temperature changes to thereby maintaining the focal plane to coincide with or substantially coincide with the image plane.

主权项

1. An integrated sensor and lens assembly, comprising:
an image sensor; a lens mount coupled to the image sensor; a lens barrel secured by the lens mount, the lens barrel comprising one or more lenses along an optical axis substantially perpendicular to a focal plane, the lens barrel comprising a first material that expands or contracts in response to a temperature change according to a first coefficient of thermal expansion, wherein expansion of the lens barrel causes a first shift in the focal plane in a first direction along the optical axis; and a pair of prisms intersecting the optical axis, the prisms comprising a second material that expands or contracts in response to the temperature change according to a second coefficient of thermal expansion to cause a first change in combined thickness of the pair of prisms along the optical axis; a pair of pushrods coupled between the lens mount and the pair of prisms, the pair of pushrods comprising a third material that expands or contracts in response to the temperature change according to a third coefficient of thermal expansion, wherein expansion of the pair of pushrods causes a second change in combined thickness of the pair of prisms along the optical axis; and wherein the second material, third material, and geometry of the pair of prisms are configured such that the first change in combined thickness and the second change in combined thickness of the pair of prisms cause a second shift in the focal plane in a second direction along the optical axis opposite the first direction.