Patent attributes
An apparatus for measuring stray light in a lens module includes a light source, an image sensor, an object distance adjusting unit, and an object distance measuring device. The light source is disposed at an object side of the lens module for emitting light to the lens module. The image sensor is disposed at an image side of the lens module for measuring an intensity of stray light coming into the lens module. The object distance adjusting unit includes an opaque barrier defining a slit therein, and a laser aligned with the slit, the laser being configured for emitting a laser light beam through the slit thereby forming a light spot serving as an object. The object distance measuring device is configured for measuring an object distance. The opaque barrier of the object distance adjusting unit is movable relative to the wavefront sensor so as to adjust the object distance.