Patent ID: 6266052
Filing Date: 2001-07-24
Classification: G06F,G06Q,G09G,H04B

Abstract:
A back-up power system for an information display system, the information display system comprising a control circuit for generating information and power signals, a plurality of electronic display tags, and a conductor for carrying information and power signals between the control circuit and the display tags, each display tag having a processor, a memory interfaced with the processor and containing a tag address and display data, and a visual display for displaying the display data contained in the memory, the back-up power system comprising:an uninterruptible power supply connected to the control circuit for providing the control circuit with continuous power in the event of a power failure;control means responsive to a power failure for supplying power to said display tags from said uninterruptible power supply for a first prescribed period of time following the power failure;means responsive to expiration of said first prescribed period of time and continuation of the power failure for turning off the tag displays while continuing to supply power to the tags from said uninterruptible power supply to retain the address and display data stored in the display tags' memories for a second prescribed period of time; andmeans responsive to expiration of said second prescribed period of time and continuation of the power failure for turning off power to the tag memory but retaining the tag address.