Electronic camera and automatic focusing method

Abstract

The present invention provides an electronic camera adapted to perform an accurate auto focus control operation at high speed. The electronic camera comprising a C-MOS image sensor, a lens section having a focusing lens, a wobbling control section for generating a wobbling control signal for causing the focusing lens to do a wobbling operation of repeating a series of operations including a near side drive operation of driving the focusing lens to move to the near side, a near side stop operation of stopping the focusing lens at the near side, a far side drive operation of driving the focusing lens to move to the far side and a far side stop operation of stopping the focusing lens at the far side at every 2 × n field periods, an estimated in focus value computing section for generating an estimated in focus value to indicate the degree of in focus of the image of the object of shooting, an in focus direction determining section for computing the quantity of change in the estimated in focus value during the wobbling operation and determining the direction to be followed by the focusing lens to become in focus on the basis of the quantity of change, and a drive section for driving the focusing lens to move and become in focus and driving the focusing lens based on the wobbling control signal. The wobbling control section is adapted to generate the wobbling control signal so as to make the central timing in the time period of exposure to light of the central pixel of the predetermined range in the image substantially agree with the central timing of the period of the near side stop operation and that of the period of the far side stop operation.

Description

[0001] This application is a divisional application of a patent application with an application date of July 1, 2005, an application number of 200910006255.8, and an invention title of "Electronic Camera and Automatic Focusing Method". The entire contents of which are hereby incorporated by reference. technical field [0002] The invention relates to an electronic camera and an automatic focusing method. Background technique [0003] Electronic image pickup devices formed using a CCD (Charge Coupled Device) image sensor as a photoelectric conversion element, or so-called digital cameras, are popular in the market. [0004] Such digital cameras are typically equipped with an autofocus control feature that automatically focuses the camera lens. Although there are a variety of automatic focus control systems available for digital cameras, the current system that generates focus evaluation values ​​by extracting the contrast and high-frequency components of the detection range o...

AI Technical Summary

Problems solved by technology

Although there are a variety of automatic focus control systems available for digital cameras, the current system that generates focus evaluation values ​​by extracting the contrast and high-frequency components of the detection range of the captured image, and adjusting the lens position to maximize the focus evaluation value is still mainstream

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