Driving innovation: Sheba unveils world’s first autofocus car camera

“Over the past two decades we all have seen how high-resolution sensors have dramatically improved cameras on our phones. A key enabler for such high-resolution imaging was the adoption of autofocus actuators,” said Faez Ba-Tis, CEO and co-founder of Sheba, in statement.

The Canadian firm specializes in developing high-end MEMS actuators for optical solutions, including autofocus (AF), Optical Image Stabilization (OIS), and super-resolution (SR) for cameras.

Thermal expansion solution

As the optics and camera components expand with temperature, automotive cameras frequently struggle to maintain focus stability and image quality.

As the automotive sensor market gravitates towards higher resolution, the issue intensifies with smaller pixel sizes, exacerbating challenges. Because of the wider temperature range, smaller pixels necessitate more exact alignment of the optics to ensure that light is focused on each pixel precisely.

According to the company, any misalignment caused by thermal expansion or contraction can result in blurring or distortion, which is problematic for any camera, especially automotive ones.

Instead of shifting the lenses to account for this thermal expansion, Sheba’s patented technology shifts the lightweight sensor along the optical axis.

The image sensor weighs 2 to 3 percent of the optical lens, making it lighter and easier to handle. This allows for ultra-fast and accurate autofocus performance even in temperature variations.

Sheba highlights that this cutting-edge method allows vehicle cameras to benefit from the advantages of high-resolution sensors, including digital zooming and incredibly accurate object detection (for example, traffic signs, animals, and pedestrians).

Advanced MEMS micro-actuators

Decades-long barriers, like the absence of reliable automotive-compatible autofocus actuators and challenges with thermal expansion, have hindered high-resolution sensor adoption in auto cameras.

Offering a solution, Sheba’s MEMS micro-actuators offer precision, reliability, and thermal stability across all automotive grades, spanning from -40 to 302 degrees Fahrenheit (-40 to 150 degrees Celsius).

It has been shown that MEMS actuators with comb-drive electrode configurations have a poor structural component that leads to restricted force and out-of-plane stroke.

However, roughly ten years ago, the founders of Sheba Microsystems—who were then at the University of Toronto—introduced a novel solution by creating the piston-tube electrode design.

A technological advancement

The company’s version is a result of advancements in piston-tube technology, overcoming the limitations of the conventional comb-drive structure through this innovation.

Because the piston-tube electrodes have a higher capacitive area, they can produce a significant force and stroke. With this development, Sheba’s MEMS actuators in embedded vision and tiny cameras can now perform optical image stabilization and autofocus.

Also, Sheba’s patented method shifts the sensor for autofocus, bypassing lens movement. Overcoming challenges, they directly wire-bond from the sensor to the outer PCB, ensuring stable bonds even under severe conditions.

“Sheba MEMS technology solves for thermal expansion and produces consistent, high-quality imaging from existing 8 MP sensors, but our technology also paves the road towards the adoption of even higher resolution image sensors,” concluded the firm.