| 摘要 |
PURPOSE:To detect accurately the fact that zooming reaches the telephoto end or the wide end, without depending on a variation of an image of an object in a finder, by measuring a driving current value of a motor for driving a moving element for zooming. CONSTITUTION:When a changeover switch S is turned on to a telephoto terminal T side, transistors TR1, TR'1 conduct, a currnt flows to the left from the right to a motor 13, and a zoom ring is turned to the telephoto side. Also, when the changeover switch S is turned on to a wide terminal W side, transistors TR2, TR'2 conduct, a current flows to the right from the left to the motor 13, and the zoom ring is turned to the wide side. A voltage drop across a resistance R0 is varied by a load current flowing to the motor 13 at the time of zooming, therefore, by utilizing this voltage drop V0, it is detected that turning of the zoom ring reaches the telephoto end or the wide end. |
