Automatic focus control device and automatic focus detecting device

Abstract

Abstract PURPOSE: To make focusing not be affected by the change-over of the F value mode by calculating the quantity of defocusing from the output signal of 2 pairs of photoelectric element groups detected by dividing a subject image, correcting the defocusing signal according to the change- over of the F value mode and making the relation between the quantity of defocusing and the leading-out distance of a photographic lens constant. CONSTITUTION: In order to find phase difference j' of a subject image from outputs a 1 Wa n and b 1 Wb n of CCD25 consisting of 2 pairs of photoelectric element groups A 1 WA n and B 1 WB n , a i and a j are stored in memories 33 and 32 and signals shifted by j, b i-j and b i+1-j , are stored in memories 36 and 35 respectively through AD converter 39, memories 30 and 31 and shifting circuit 34. Peak value Y 1 of integration value of (a i -b ij ) q can be obtained from the output of memories 33 and 36 through differential circuit 37 and cumulative circuit 39. The output of zero-cross detecting circuit 47 for the similar operational output of the integration value of the difference between (a i -b i+1-j ) p and (a i+1 -b i-j ) p and phse difference j' from Y 1 are sent from operational circuit 48 to control circuit 26, the variation of j' caused by F value switching is denied through F value mode circuit 50 and a fixed defocusing signal is outputted from circuit 26. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Kunihiko Araki

Bibliographic Details