Focus control device and imaging device

Abstract

In a contrast AF control prior to main imaging, a focus position of a lens of a focus lens (2a) is detected by using, at the highest priority, an AF evaluation value acquired by using a high pass filter (601) among the high pass filter (601) and band pass filters (602) to (604) arranged in an AF circuit (600) and having different frequency characteristics. Thus, a focus control device is set so that when imaging an ordinary object, the HPF (601) is used with a higher priority for performing extraction while counting a component of a high frequency band increasing in the image data. Accordingly, it is possible to perform highly-accurate focus control for various objects.

Description

Technical field The invention relates to a focus control technology. Background technique Conventionally, as autofocus (AF) control performed by an imaging device such as a silver salt camera, a so-called phase difference method is often used. However, it is known that the AF control of this phase difference method has poor accuracy especially in small f-number photography. On the other hand, in recent years, with the advent of digital cameras, imaging devices employing AF control of the so-called contrast method (mountain method) have become widespread. Furthermore, it is known that the AF control of the general contrast method has higher AF accuracy than the AF control of the phase difference method. Therefore, it is conceivable that the AF control of the phase difference method and the contrast method can be used together to improve the AF accuracy. Therefore, in contrast-based AF control, high-frequency components extracted using a high-pass filter are generally used as ev...

AI Technical Summary

Problems solved by technology

However, in the technique disclosed in Japanese Patent Application Laid-Open No. 05-308556, it is difficult to determine the membership function, and it is difficult to perform high-precision AF control

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