| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a highly convenient electrical device and projection type display device capable of using an appropriate filter according to the use environment without bothering a user. <P>SOLUTION: This projector is provided with a filter cassette 40 mounted in a projector body. The filter cassette 40 is provided with a multi filter 409 composed of a first filter 409a and a second filter 409b which are different from each other in performance, and take-up shafts 407, 408 around which the multi filter 409 is mounted. The take-up shafts 407, 408 are rotated by a take-up motor 701. A control part 801 discerns the type of unwanted substances contained in external air that is suctioned into the projector body, on the basis of a pulse signal from a dust sensor 92. The control part activates the take-up motor 701 and shifts the multi filter 409 so that a filter corresponding to the discerned type is used. <P>COPYRIGHT: (C)2012,JPO&INPIT |
