A lamp assembly includes a diffraction grating, such as a CD, CD-ROM, DVD, laserdisc, mini disc or the like, positioned with respect to the light bulb for reflecting light from the bulb to produce a pleasing spectral visual effect....http://www.google.ca/patents/US6312142?utm_source=gb-gplus-sharePatent US6312142 - Lamp assembly with diffraction grating reflector
