Image capturing device and hybrid auto-focus method thereof

An image capturing device comprising:

• a distance sensor, configured for distance detection;
• an image sensor, comprising a lens and a sensing array, wherein the sensing array comprises a plurality of pixels, and wherein a part of the pixels are configured as partially-shielded phase detection pixels for phase detection;
• a memory;
• and
• a processor, coupled to the distance sensor, the image sensor, and the memory, and configured for obtaining distance sensor data (DS data) and phase detection data (PD data) respectively from the distance sensor and the sensing array, controlling the lens to perform a coarse search a focusing range by switching the image sensor between a distance sensor auto-focus (DSAF) mode and a phase detection auto-focus (PDAF) mode based on the DS data and the PD data so as to determine a fine-search range, controlling the lens to perform a fine search within the fine-search range in a contrast detection auto-focus (CDAF) mode so as to determine an optimal focusing lens position, and controlling the lens to move to the optimal focusing lens position.

An auto-focus method, adapted to an image capturing device comprising two image sensors, wherein each of the image sensors comprises a lens and a sensing array, and wherein the auto-focus method comprises the following steps:

• obtaining distance sensor data (DS data) from a distance sensor and disparity data (DP data) from the sensing arrays of the image sensors;
• controlling the lens to perform a coarse search within a focusing range by switching the image sensors between a distance sensor auto-focus (DSAF) mode and a disparity detection auto-focus (DDAF) mode based on the DS data and the DP data so as to determine a coarse-search focusing position;
• setting a fine-search range according to the coarse-search focusing position;
• controlling the lens to perform a fine search within the fine-search range in a contrast detection auto-focus (CDAF) mode so as to determine an optimal focusing lens position;
• and
• controlling the lenses to move to the optimal focusing lens position.