Automatic focus adjuster for video camera

Abstract

Abstract PURPOSE:To automatically adjust the focus without using any range finder, by installing a solid-state image pickup element under conditions where the element can be moved in the direction of an optical axis and by utilizing the signal from the solid-state image pickup element for automatic focusing. CONSTITUTION:The image of an object 2 is formed on a solid-state image pickup element 3 by an image pickup lens 1. The solid-state image pickup element 3 is fixed to a moving coil 4a which is movable in the direction of an optical axis and moved leftward along the optical axis by the electric current supplied from a moving coil driving circuit 6. The output from the image pickup element 3 is inputted into an auto-focus arithmetic 7 and the image forming condition is found through an arithmetic operation in the circuit 7. When the output from the image pickup element 3 is detected as in-focus state, the moving coil 4 is stopped by fixing the output of the moving coil driving circuit 6 to the focusing location and the in-focus image signal is sent to the recording device by stopping the image pickup element at the location.

Inventors

• 👤 Noboru Arai
• 👤 登 荒井
• 👤 Takahiro Oota
• 👤 隆啓 太田
• 👤 Masashi Kantani
• 👤 乾谷　正史

Bibliographic Details