Autofocus and optical image stabilizer system
View Patent ↗The present invention is a mechanism to achieve autofocus (AF) and optical image stabilization (OIS) to counteract hand-shake by tilting the lens and the image sensor simultaneously such that no vignetting effect is introduced to the image. The present invention removes the blur or distortion (vignetting effect) by incorporating an actuator beneath the image sensor to tilt the image sensor in conjunction with the lens barrel tilt to achieve OIS. Such simultaneous and coordinated tilting to the optical elements in the camera (lens barrel and image sensor) guarantees that the plane of the reflected image and the plane of the image sensor are both parallel, and aberrations free images are constructed.
1. An autofocus (AF) and optical image stabilization (OIS) system, comprising:
a) a first actuator to hold and move a lens barrel;
b) a second actuator to move an image sensor, wherein the second actuator is not rigidly connected to the first actuator, and wherein the first and the second actuators are independently controlled,
c) the first and the second actuators are MEMS piston-tube actuators, wherein each of said actuators provide a 3 degrees-of-freedom motion comprising of a translation along a z-axis being perpendicular to a plane of each actuator, and a bi-axial tilt about an x-axis and a y-axis being along the plane of each actuator, and wherein both of said actuators tilt about the x- and the y-axes to achieve OIS and translate along the z-axis to achieve AF, and wherein AF is achieved by moving one or both of the image sensor and the lens barrel, and the OIS is achieved by tilting the lens barrel using the lens barrel actuator around the x- and y-axes and the image sensor actuator is tilted independently around the x- and y-axes to ensure a sensor plane is rotated to coincide with an image plane.
2. The system in claim 1 , further having an IR filter and a flexible/PCB circuit.
3. The system of claim 1 , wherein said first actuator comprises of a moving part and a fixed part, and wherein the moving part comprises of an arrays of openings (tubes) that surround a central through hole, and are attached to an outer periphery of the first actuator through a set of mechanical springs, and wherein the fixed part comprises of a multiple arrays of pistons that are protruding vertically and are aligned with the arrays of openings in the moving part, and wherein the lens barrel is integrated at the central through hole.
4. The system of claim 1 , wherein said second actuator comprises of an actuator-moving part and an actuator-fixed part, and wherein the actuator-moving part comprises of an arrays of actuator-openings (tubes) that are attached to the outer periphery of the second actuator through a set of actuator-mechanical springs, and wherein the actuator-fixed part comprises of a multiple arrays of actuator-pistons that are protruding vertically and are aligned with the arrays of actuator-openings in the actuator-moving part, and wherein the second actuator is able to translate the image sensor along the z-axis to achieve auto-focus and/or to tilt it about the x and the y axes to achieve OIS.