Automatic focus adjusting device

Abstract

Abstract PURPOSE:To make stable following correction possible, by correcting defocusing variation caused by the movement of an object by performing filtering and, when a defocusing quantity caused by the movement of the object is small, performing an averaging process in which weight of previous data is increased. CONSTITUTION:A controller 109 finds a defocusing quantity ¦DELTA¦ from the data of an object supplied from an interface circuit 108 based on data K from a reading circuit 104 and calculates a pulse number N by calculating K.¦DELTA¦. Moreover, the controller 109 rotates a motor MO1 clockwise or counterclockwise through a motor driver 114 in accordance with a signal in the defocusing direction found from the data of the object and, at the moment when pulses equal to the calculated value N is inputted to the controller 109 from an encoder 113, judges that a lens system for focus adjustment has moved by a moving quantity DELTAd to a focusing position and stops the motor MO1. When focusing to the object is completed after such focus adjustment, a prescribed signal is sent to a display circuit 115 and completion of focus adjustment and distance to the object are displayed.

Inventors

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

Bibliographic Details