Automatic focusing device

Abstract

Abstract PURPOSE:To perfectly remove the influence of the flicker component of illumination, and to attain stable focusing, by finding a focal point voltage by dividing a high-pass area component by a luminance component. CONSTITUTION:A high-pass area component detecting means 3 detects a high- pass area component H(N) by extracting and detecting a prescribed high-pass area component from a video signal S. The high-pass area component H(N) is digitized at an A/D converter 33, and is supplied to a divider 5. Meanwhile, a luminance component detecting means 4 detects a luminance component I(N) by extracting and detecting the luminance component from the video signal S1, and the luminance component I(N) is digitized at an A/D converter 43, and is supplied to the divider 5. The divider 5 takes out the focal point voltage E(N) by dividing the high-pass area component H(N) by the luminance component I(N). By performing the focusing based on the focal point voltage E(N), the influence of the flicker component of the illumination can be removed.

Inventors

• 👤 Kazuhiko Ueda
• 👤 和彦 上田

Bibliographic Details