Illumination device for liquid crystal display apparatus

摘要

An illumination device for a liquid crystal display apparatus to be disposed on a back side of a liquid crystal display panel is constituted by a plurality of illumination circuits, and plural hot cathode tubes including at least one hot cathode tube associated with each illumination circuit. Each illumination circuit includes a life detection circuit for detecting an end of life of a hot cathode tube, and a turn-off circuit for turning off the hot cathode tube depending on an output of the life detection circuit. Each illumination circuit controls said at least one hot cathode tube associated therewith independently from the other hot cathode tubes. As a result, even when a hot cathode tube approaches its end of life, the illumination device can be partially turned off to allow an operator to continue the operation on the liquid crystal display apparatus.