| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection installation and an operation protection method for a projector. SOLUTION: The projection installation comprises; a power supplier; a plurality of cooling fans which are provided in at least one of a projection lamp and an image processing system and reduce the temperatures in their installation places and output pulse signals of corresponding rotation speeds on the basis of respective rotation speeds; a segment charging circuit which receives pulse signals of the fan and generate a continuous charging signal; a reference voltage comparison circuit which compares a voltage level of the continuous charging signal with a preliminarily set reference voltage level and generates another voltage level; a start delayed signal generation circuit which is started after a specific delay time to generate a signal; an AND logic gate which receives the voltage level outputted from the reference voltage comparison circuit and the signal from the start delayed signal generation circuit and outputs a voltage corresponding to them; a status latch which receives the voltage signal outputted from the AND logic gate and sends a protection start signal to at least one of the power supplier, the projection lamp, and the image processing system in response to change of the output state of the AND logic gate; and a protection driving circuit. COPYRIGHT: (C)2004,JPO&NCIPI
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