A MEMS mirror is a product where a moving mirror is formed on silicon using MEMS technology to reflect and scan a laser beam incident on the mirror surface for performing laser scanning.
This section presents the drive methods of MEMS mirrors, features of MEMS mirrors, and examples of their applications.
MEMS mirrors are so-called moving mirrors formed using MEMS technology and are available using piezoelectric, electromagnetic, electrostatic, and other drive methods. A MEMS mirror has a small number of parts, making it difficult to break, and is small and easy to mass-produce. Consequently, it is used in a wide range of mobile devices, projectors, and other equipment.
A piezoelectric film is formed on a silicon wafer, and the warping motion caused by applying voltage is transmitted to the mirror through a hinge to move it. This method is characterized by its small size and ability to maintain high output.
A current is applied to a coil around the mirror in a magnetic field to drive the mirror. This method is characterized by the ability to drive at a low voltage and being easy to handle.
The mirror is moved by actuators attached to both ends of the mirror. Because this method uses only a small amount of power, it enables power-saving operation.
MEMS mirrors have long been used in scanners, projectors, and other devices. Recently, they are being used in light detection and ranging (LiDAR), head-up display (HUD), head-mounted display (HMD), and other applications.
Among these, LiDAR is said to be an essential technology for realizing fully automated driving, and demand for LiDAR is increasing every year.
LiDAR is a technology that uses light to detect and measure distance. Near infrared light, visible light, and ultraviolet light are used to illuminate an object, and the reflected light is detected by an optical sensor to measure the distance.
MEMS mirrors play an important role in supporting this LiDAR technology.