SMA-Driven Optical Assembly for Compact Camera Module Autofocus

The patent replaces the motor mechanism with a shape memory alloy (SMA) line that uses thermal actuation instead of electromagnetic actuation. The SMA line is driven by temperature changes to produce longitudinal movement of the lens, eliminating the need for a motor and significantly reducing the volume of the camera module.

The patent changes the actuation parameter from electromagnetic (motor) to thermal (SMA line). By using temperature as the driving parameter, the system achieves lens movement without requiring the bulky motor structure, thereby resolving the volume contradiction while maintaining auto-focus functionality.

The patent substitutes the electromagnetic force generation system (motor with magnet and coil) with a thermal actuation system (SMA line). The SMA line generates the necessary thrust through thermal expansion and phase transformation, eliminating the need for large-volume magnets while maintaining effective lens driving capability.

The patent changes the force generation mechanism from electromagnetic to thermal. By utilizing temperature-induced phase transformation in the SMA material, the system generates the required thrust without the volume constraints associated with electromagnetic actuators, enabling effective lens control with minimal volume.

The patent replaces the motor-driven mechanical system with an SMA line-based thermal actuation system. This substitution enables more efficient space utilization, as the SMA line can achieve the required lens movement stroke within a more compact configuration, allowing camera module miniaturization without sacrificing lens mobility.

The patent utilizes the thermal dimension (temperature control) to achieve lens movement, rather than relying solely on mechanical space for motor operation. This dimensional shift allows the system to achieve the necessary movement stroke within a reduced physical volume by leveraging thermal actuation efficiency.