Focusing apparatus capable of changing a driving amount of a focus lens based on focus detection results acquired at different focus positions

摘要

A focusing apparatus with a photoelectric converter which photoelectrically converts at least a pair of optical images formed by light fluxes that have passed a focus lens to output at least a pair of image signals, a phase difference detector which detects a phase difference between the pair of output image signals, and a driving amount calculator which calculates a driving amount of the focus lens based upon the detected phase difference. The driving amount calculator changes the calculated driving amount, in accordance with a first driving amount corresponding to a detected phase difference when the focus lens is located at a first position, a second driving amount corresponding to the detected phase difference when the focus lens is located at a second position, and a relationship between the first and second positions.

主权项

1. A focusing apparatus comprising:
a photoelectric converter configured to photoelectrically convert at least a pair of optical images formed by light fluxes that have passed a focus lens and to output signals configured by at least a pair of image signals; a detector configured to detect a phase difference between the pair of image signals based upon the signals from the photoelectric converter; and a calculator configured to calculate a defocus amount based upon the signals from the photoelectric converter and the phase difference detected by the detector, wherein the calculator changes a driving amount of the focus lens in accordance with information based upon a position of the focus lens and a changing amount between a first defocus amount and a second defocus amount, wherein the first defocus amount is calculated with the signals from the photoelectric converter when the focus lens is located at a first position, and the second defocus amount is calculated with the signals from the photoelectric converter when the focus lens is located at a second position, and wherein the driving amount of the focus lens calculated based upon the phase difference is changed in accordance with a ratio between a difference between the first position and the second position of the focus lens, and a difference between a first defocus amount based on the phase difference detected by the detector in the case where the focus lens is located at the first position and a second defocus amount based on the phase difference detected by the detector in the case where the focus lens is located at the second position, the second position being a position where the focus lens is driven from the first position in accordance with the first defocus amount based on the phase difference detected by the detector.