A circular arc illumination apparatus includes a light source device, a condensing optical system for condensing rays emitted by the light source device, and a scanning optical system for transmitting the rays to an object to be scanned. The scanning optical system includes a driving device, a rotating...http://www.google.com.au/patents/US5390044?utm_source=gb-gplus-sharePatent US5390044 - Circular arc illumination apparatus
