Optical unit including a substrate and optical element supported on the substrate such that thermal stresses are prevented from being exerted on the optical element

摘要

An optical unit as used for an optical sensor, including a substrate, one or more optical elements fixedly supported by the substrate, and an protecting arrangement associated with the substrate and at least one of the optical elements, for protecting each associated optical element from thermal stresses exerted thereto due to a difference in thermal expansion coefficient between the substrate and the associated optical element. The protecting arrangement may consist of at least one intermediate body interposed between the substrate and the associated optical element. Each intermediate body has a thermal expansion coefficient close to that of the associated optical element. Alternatively, the protecting arrangement may consist of a constricted protecting portion such as protrusions or slots formed on one of the associated optical elements and the substrate, such that the protecting portion defines an adjoining interface between the optical element and the substrate, or is located adjacent to the adjoining interface.