| 摘要 |
A projection screen including a rectangular film having a back surface, a front surface and a periphery, a support frame and chamber connected to the periphery of the film for defining the shape of the periphery of the film, a device for creating a pressure differential between the front surface and the back surface of the film, a sensor for sensing the position of the film and indirectly sense the pressure differential on the film and a controller for controlling the device for creating the pressure differential in response to the sensor such that the position of the film is a predetermined position as a result of some pressure differential whereby the shape of the film is set by the shape of the frame which is connected to the periphery of the film and by the predetermined position of the film resulting from the pressure differential. 12 |
