Patent ID: 7795819

Claim:
In combination, at least one electric discharge lamp capable of generating an output pulse of a range of wavelengths in the visible spectrum, said output pulse having a predetermined time interval and a predetermined total electrical energy input for said pulse, and a drive circuit for delivering a plurality of energy pulses to said electrical discharge lamp, the drive circuit comprising a) storage capacitor means capable of storing said electrical energy input, b) charge means for charging said storage capacitor means; c) switch means for permitting delivery of electrical energy from said storage capacitor means to said discharge lamp; and d) drive means for selectively opening and closing said switch means throughout said predetermined time interval so as to deliver a plurality of packets of energy from said storage capacitor means to said discharge lamp, each said packet being of duration less than said predetermined time interval; the combination further comprising sensor means for sensing an optical output from the discharge lamp; and control means for operating said drive means in response to variations in optical output detected by said sensor means.