| 摘要 |
PURPOSE:To simplify an adjusting mechanism greatly by setting a photographic lens at either one of two different distance positions over the entire range of the distance of an object to the degree that no trouble is brought about practically. CONSTITUTION:As a film is wound, shutter 3 is charged and focus adjusting lever 25 moves to left up to stopper 30 to hole lens barrel 2 at the short-distance photographing position. When shutter button 4 is pushed down, light emitting diode 14 emits a pulsing light beam within the range of an object. If there is no object at a short distance, contact 19A is not opened because sufficient reflected light arrives at photodetector 15, and then electromagnet 22 is energized to move lens barrel 2 to a long distance photographing position before shutter 3 is put into operation. When object 1 resides at a short-distance, only a reflected light component appears at the output side of AC-component extracting circuit 17 to open contact 19A. Therefore, electromagnet 22 is not energized and the shutter is operated as lens barrel 2 is at the short-distance photographing position. Thus, the adjusting mechanism can be simplified. |
