| 摘要 |
PURPOSE:To automatically control an optimum operation condition in accordance with the use state of a device and the environment by providing a bi- directional information communicating means between the control circuit of a liquid crystal back light and an operation processor. CONSTITUTION:The serial voltage of a serial power source 2 is high frequency- switched by a switching circuit 3 so as to be converted to a high frequency voltage, and then, it is converted to a high voltage by a ballast circuit 4 so as to be supplied to a discharge lamp 5, and then, the lamp 5 is turned on. The lamp 5 is lighted in a stable state by the action of the ballast circuit 4 after the lamp is turned on, and it is viewed through a liquid crystal plate 6, and the liquid crystal plate 6 is controlled by a controller 9 so that an image may be formed. And the control circuit 1 is connected with the operation processor 29 by the bi-directional information communicating means 27, and control data for the lighting device 7 is transmitted from the operation processor 29 to the control circuit 1, and also, the data on the operation state of the lighting device 7 is received by the operation processor 29 so as to arithmetically process, and then, the control data is sent to the control circuit 1. |
