| 摘要 |
PURPOSE:To correct a defocusing signal by distance measurement during the movement of a lens and to put an image in focus speedily and precisely by employing a correction item corresponding to a lens moving speed for an automatic focusing camera which takes a distance measurement even during the lens movement. CONSTITUTION:A means which calculates the target movement extent of an image plane, a means which moves the lens according to the target movement extent, and a movement extent detecting means which stops a motor are provided; and the movement is divided into a starting state (a), a constant-speed state (b), and a stopping state (c), and integral correction coefficients corresponding to the respective states are used to correct the defocusing signal. The distance DELTAx from a virtual distance measurement position xm to a position x2 is gamma(x1-x2), where gamma is a parameter corresponding to the lens moving speed u(t). Then, the specific relation is used to calculate the correction coefficient gamma in the state (a) by a sensor integration start point t1 and an integral time Ts; and gamma= 0.5 is applied in the state (b) and 1-gamma is applied in the state (c). |
