| 摘要 |
PURPOSE:To reduce defocusing due to the deficiency of a projection spot by embedding a light emitting element in the center part of a projection lens, and reflecting a light beam emitted by the light emitting element by a mirror and projecting it on a subject. CONSTITUTION:The light emitting element 1 is embedded in the center part of the projection lens 2. The light beam emitted by the element 1 is image- formed on a two-split photodetecting element 5 through a photodetection lens 4. An AF circuit 9 rotates a focus ring 7 and also moves the element 5 by driving an AF motor 8 so that the quantities of light incident on the two photodetecting elements are uniform. Consequently, the focal length of the lens 2 can be made double and the overall length does not increase even when the focal length of the lens 2 made double. Thus, the focal length of the lens 2 is increased to reduce defocusing due to the deficiency of the projection spot, and the light emission device is reducible in size. |
