发明授权
US4897683A Focusing lens drive method 失效
聚焦镜头驱动方式

Focusing lens drive method
摘要:
A method for use in an automatic focusing camera for driving a focusing lens to a focused position in which the speed is changed in decreasing incremental steps as the lens approaches the focused position and the speed is made independent of changes in ambient temperature or the orientation of the camera relative to the direction of gravitational force. The speed of the lens is controlled in accordance with duty ratio data prestored in a memory and which is applied to control the duty ratio of a drive signal to a motor employed to position the focusing lens. A correction value for correcting for the effects of changes in ambient temperature is obtained prior to the start of the focusing operation and applied to correct the duty ratio of the drive signal during the actual focusing operation.
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