| 摘要 |
PURPOSE:To achieve the miniaturization of the automatic focusing drive part of the camera by linearly moving the interchangeable lens barrel by the drive device provided in the camera. CONSTITUTION:A moving barrel 1 and rotating barrel 2 fit to each other at screw parts and the barrel 2 is supported to a support barrel 3 by way of spherical bodies 6, 7. A center groove is provided in the screw parts of the barrels 1, 2 to minimize the contact face and adjust the turning resistance at the focusing. The drive device is provided in the portion in the camera where it does not interfere with the optical system optical path. Based on a focus point command, a motor 21 runs and the barrel 2 is turned by the gear and rotator. The barrel 1 is then linearly moved along the optical axis by the guide pin 5 and the groove 1c by the screws 1a, 2a. This constitution enables the achievement of even response time and smaller drive source. |
