PURPOSE: To match a variable magnification ratio to a prescribed screen size with an easy operation by providing a focusing means, the screen size inputting means specifying the size of a projection screen where light is projected, and a lens position control means.
CONSTITUTION: A projection type display device is provided with the focusing means 1 which finds a range between projection surfaces and moves the focusing system lens of the projection lens to a focusing position, and the screen size inputting means 6 which specifies the size of the projection screen where the light is projected. Further, the projection type display device is provided with a lens position control means 7 which moves a variable power lens so as to obtain a specified screen size based on the screen size information from the screen size inputting means 6 and a range-finding information from the focusing means 1. Thus, an automatically focused screen can be obtained even if a screen is big or small, with only the easy operation of specifying the size of the screen, and a video screen, etc., are appreciated in a short time after a device is set.
YANO KOTARO
TANAKA TSUNEFUMI
