Abstract: An image pick-up apparatus and a progressive auto-focus method thereof are provided. The image pick-up apparatus includes an optical system, an image sensor, a focus circuit and a lens control circuit. In the method, an image is captured by using the image sensor and whether the optical system is in focus when the image sensor captures the image is determined by the focus circuit. If the optical system is out of focus, an in-focus location of the optical system and an in-focus distance for moving the optical system to the in-focus location are calculated by the focus circuit. The in-focus distance is transformed into a shorter progressive distance and the optical system is controlled by the lens control circuit to move by the progressive distance. Aforesaid steps are repeated until the optical system is in focus and the image captured by the image sensor is output.

Abstract: An image pick-up apparatus and a progressive auto-focus method thereof are provided. The image pick-up apparatus includes an optical system, an image sensor, a focus circuit and a lens control circuit. In the method, an image is captured by using the image sensor and whether the optical system is in focus when the image sensor captures the image is determined by the focus circuit. If the optical system is out of focus, an in-focus location of the optical system and an in-focus distance for moving the optical system to the in-focus location are calculated by the focus circuit. The in-focus distance is transformed into a shorter progressive distance and the optical system is controlled by the lens control circuit to move by the progressive distance. Aforesaid steps are repeated until the optical system is in focus and the image captured by the image sensor is output.