Patent attributes
Imaging apparatus includes a housing, with imaging optics mounted in the housing and configured to form an optical image, at a focal plane within the housing, of an object outside the housing. An image sensor, including a matrix of detector elements, is positioned at the focal plane in alignment with the imaging optics and is configured to output an electronic image signal in response to optical radiation that is incident on the detector elements. At least one emitter is fixed within the housing and is configured to emit a test beam toward one or more reflective surfaces within the housing, which reflect the test beam toward the image sensor. A processor is configured to process the electronic image signal output by the image sensor in response to the reflected test beam so as to detect a change in the alignment of the image sensor with the imaging optics.