Abstract: A fluorescent cavity backlight system that provides a high efficiency light source suitable for rear illumination of transmissive electronic display devices. The inventive fluorescent cavity backlight system can be adapted to a wide variety of flat panel display applications. The invention takes a complete system approach towards designing a high efficiency backlight source. The backlight system comprises three major subassemblies: a phosphor illuminator, a fluorescent cavity, and improved control/driver electronics. Each of the subassemblies has been optimized internally, and with respect to each of the other subassemblies.

Abstract: An uninterruptible power supply provides internal connection to an auxiliary power to provide continuous device power without duplicating regulation and switching circuits. The power supply includes an AC to DC converter, a transformer and a switch applying DC power from converter to the transformer. A pulse width modulation control circuit assures a regulated output voltage while application of auxiliary power is controlled by a fixed time interval one-shot that assures a smooth transition to AC utility power upon resumption of such power following a failure. An auxiliary AC power output signal is maintained for a video monitor or other device even while operating on auxiliary power.