A light beam hardening apparatus is provided for hardening a material, such as dental material, exposed to light emitted by the light beam hardening apparatus. The light beam hardening apparatus includes a semi-conductor light emitting source operable to emit light in the visible light spectral range...http://www.google.de/patents/US6695614?utm_source=gb-gplus-sharePatent US6695614 - Light beam hardening apparatus for curing material
