An Optical filter is provided on a light receiving surface of an image sensor. The filter has a plurality of thin layers alternately laminated. The thin layers alternately consist of a dielectric layer having a high refractive index and a metal layer and each thin layer has its stress .sigma. in a range...http://www.google.co.uk/patents/US5648653?utm_source=gb-gplus-sharePatent US5648653 - Optical filter having alternately laminated thin layers provided on a light receiving surface of an image sensor
