| 摘要 |
PROBLEM TO BE SOLVED: To achieve continuous autofocus in a projector. SOLUTION: When a power source is turned on, a predetermined pattern is projected to a screen, and range-finding is performed by a range-finding unit. Distance data is calculated from a pair of output sensor data, and a focus motor is driven to perform focusing based on the data. Next, an image for viewing is projected to the screen. When the contrast of the image for viewing is very low, it is judged as a range-finding error, and focusing by the predetermined pattern is maintained as it is, then range-finding by the image for viewing is performed after three seconds elapse. When the distance data is normally obtained, it is compared with the distance data used in the previous focusing. When change exceeding a first threshold is found, a projection lens is focused based on the distance data obtained by use of the image for viewing. When the change is not found, range-finding by the image for viewing is performed at the intervals of three seconds until the power source is turned off. COPYRIGHT: (C)2008,JPO&INPIT |
