Patent ID: 8102122

Claim:
An apparatus for providing light comprising: a cathodoluminescent light emitting device having an anode and a cathode, the anode further comprising a phosphor layer for emitting light; a rectifier for connection to an external AC supply and for providing DC power with considerable ripple; apparatus for converting the DC power to high frequency AC power, the apparatus for converting the DC power to high frequency AC power comprising at least one inductor and apparatus for applying pulses of the DC power to the inductor; and voltage multiplying and rectifying apparatus for providing high voltage DC power from the high frequency AC power, the high voltage DC power for supplying a voltage difference between the anode and cathode of the cathodoluminescent light emitting device; wherein the apparatus for applying the DC power to the inductor responds to a phase of the external AC supply to by adapting at least one of pulsewidth and pulserate to optimize a power factor of the apparatus for providing light.