Automatic focusing device

Abstract

Abstract PURPOSE:To obtain a desired focused state in a short time by calculating a defocus amount in the present time point, which follows a movement of an object, setting this defocus amount as a target value, and correcting a lens. CONSTITUTION:At present, the device is in the time point TM3 when an arithmetic operation C3 has been ended, and a defocus amount DFc in the center point TMI of an integration I3 is also derived, but in the present time point TM3, an object moves already. When a moving extent of the object extending from the time point TMIL to TMI is denoted as WR, and a moving extent of the object in the present time point TM3 is denoted as X, {(TMI-TM 3)/(TMIL-TMI)}XWR is formed, and by this corrected value WR, a lens driving amount ERR is corrected. This lens driving amount ERR shows a distance to the object in the present time point by a pulse count number unit. In this way, by setting the corrected target value as the present time point, a distance to the object can be displayed by a real time to match an arithmetic operation timing.

Inventors

• 👤 Masataka Hamada
• 👤 正隆 浜田
• 👤 Kenji Ishibashi
• 👤 賢司 石橋
• 👤 Tokuji Ishida
• 👤 石田　徳治

Bibliographic Details