| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accurately detect the rotation state (presence or absence of rotation and the limiting position of a range of the rotation) of a lens barrel and to avoid increase in the scale of a lens barrel detecting apparatus. <P>SOLUTION: A lens barrel rotating detection apparatus is provided with a rotation detecting ring 71 which corotates with the rotation of the lens barrel and three photo-couplers 75 to 77. In the rotation detecting ring 71, light-transmitting portions 72 and light-shielding portions 73 detectable by the photo-couplers 75 to 77 are arranged alternately, at eachθ°(=4°) with respect to the center of rotation, and a shutter 74 is formed at the limiting position of a range of the rotation. The first photocoupler 75 and the second photocoupler 76 are arranged at the interval of (2θ+(θ/2))°, with respect to the center of the rotation of the rotation detecting ring 71, while the second photocoupler 76 and the third photocoupler 77 are arranged at an interval of (2θ-(θ/2))°. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
