Sony announced today the forthcoming release of six new types of stacked CMOS image sensors with a global shutter function achieved using a back-illuminated pixel structure for industrial equipment applications.

Sony says that the ew sensors will be both compact and capable of high imaging performance without distortion of moving objects. They will employ Sony’s Pregius S — stacked CMOS image sensor technology, which comes with global shutter functionality made possible by Sony’s proprietary back-illuminated pixel structure, first announced in March 2019.

As automation and labor-saving measures are increasingly implemented in factories and logistics, machine vision cameras play an increasingly important role.

Until now, increasing the number of pixels in image sensors to improve resolution has resulted in the downside of increased chip and camera size. However, if the pixel size is reduced to prevent increasing the camera size, then the light-accumulating area per pixel will correspondingly decrease, resulting in a drop in the sensitivity and saturation signal level. This results in image quality degradation, in turn leading to degradation in recognition and detection performance.

Sony says that the new sensor products provide a global shutter function enabling imaging without distorting moving objects. The proprietary back-illuminated pixel structure allows for a compact size of only 2.74µm square, which is about 63% of the conventional pixel area, but still maintaining pixel characteristics such as sensitivity and saturation signal level. While using the same optical system as previous models, the number of pixels has been increased and the package size (area) has been reduced to about 91%. This makes it possible to achieve a compact C-mount lens-compatible machine vision camera with higher resolution for improved inspection precision.

The new products achieve a readout frame rate approximately 2.4 times the speed of conventional image sensors thanks to the highly flexible wiring layout of the back-illuminated pixel structure, and the use of the Scalable Low Voltage Signaling with Embedded Clock (SLVS-EC) high-speed interface standard developed by Sony. This results in shorter process time for measurements and inspections.

Further, the stacked structure allows for embedding various signal processing circuits such as the high dynamic range (HDR) processing circuit that can prevent distortion in moving objects, thereby enabling myriad functions for various machine vision applications in a package more compact than conventional image sensors.