发明授权
- 专利标题: Camera system and lens apparatus
- 专利标题(中): 相机系统和镜头设备
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申请号: US10172655申请日: 2002-06-14
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公开(公告)号: US06603929B2公开(公告)日: 2003-08-05
- 发明人: Masanori Ishikawa , Toru Kawai , Ryuji Suzuki , Seiichi Kashiwaba , Shigeki Sato
- 申请人: Masanori Ishikawa , Toru Kawai , Ryuji Suzuki , Seiichi Kashiwaba , Shigeki Sato
- 优先权: JP2001-186751 20010620
- 主分类号: G03B1336
- IPC分类号: G03B1336
摘要:
The present invention discloses a camera system comprising: a first focus detection unit, which detects the focusing condition of an image-taking optical system; a second focus detection unit, which detects the focusing condition of the image-taking optical system at a higher precision than the first focus detection unit; and a control circuit, which controls a stepping motor for driving a focus lens. The control circuit performs closed loop control for driving the stepping motor based on the output of a rotation detector, which detects the rotation phase of the stepping motor, when controlling the stepping motor using the information based on the output of the first focus detection unit, and performs open control for driving the stepping motor a predetermined number of steps at a time, when controlling the stepping motor using the information based on the output of the second focus detection unit. The autofocus process is thereby made high in speed and high in precision at the same time.
公开/授权文献
- US20030012568A1 Camera system and lens apparatus 公开/授权日:2003-01-16