Automatic focusing regulator

Abstract

The present invention provides an automatic focus adjustment device, which can quickly find the focus point without making the main body larger. This apparatus guides the light from the object 1 to the light-receiving section 3 through the optical section 2, and the light-receiving section 3 captures the object 1 as a digital image. A movable separation prism 4 is arranged between a position in front of the light-receiving surface of the light-receiving section 3 in the optical path of the optical section 2 and a position outside the optical path of the optical section 2 . Then, the shift amount of the video signal based on the light beam passing through the demultiplexing prism 4 is detected by the control unit 9, and the focus adjustment of the optical unit 2 is performed according to the shift amount.

Description

technical field [0001] The invention relates to an automatic focus adjustment device. Background technique [0002] A digital camera has an imaging device that can electrically detect a video signal through a photographic lens. There is known a technology related to a digital camera that uses brightness information of a video signal output from the image pickup device to perform focus adjustment to obtain a correct focus state. [0003] This technique is a technique for fine-tuning the photographic lens to obtain a lens position with good image contrast. Because it controls the photographic lens to move to a high-contrast position, it is generally called the sharpness detection method (contrast method) AF. [0004] On the other hand, in a single-lens reflex camera of a film camera (Ginshio Camera), AF according to the TTL (Through The Lens) phase difference method is generally used. The light beam from the subject taken in through the photographic lens is reflected by the ...

AI Technical Summary

Problems solved by technology

[0006] However, although the AF of the above-mentioned contrast method is beneficial to the miniaturization of the camera body from the point of view that the sensor for AF can also be used as the sensor for photography, it is necessary to move the photographic lens in the direction where the contrast of the image is good in order to obtain a better image contrast. Out of the focus position, so the adjustment amount and adjustment direction of the focus adjustment cannot be detected with one sensor

Therefore, there are problems that it takes time to move the photographic lens, and the so-called release time lag in camera technology becomes longer

However, there is a problem that since a secondary imaging optical system is required to extract a part of the light beam from the subject, divide it into pupils, and perform re-imaging, the number of parts increases, the cost increases, and the camera body itself becomes larger

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