Pregius S Sensors - Gen 4 now appearing in industrial cameras

In April 2019 Sony announced their 4th Generation Pregius CMOS sensors - Pregius S. We are now seeing them released in the latest models of the world's leading industrial cameras from Adept Turnkey. Some of the Pregius sensors released to date include:

- The high speed models that run up to 159 fps IMX530 (24MP), IMX531 (20MP), IMX532 (16MP).

- The standard models IMX540 (24MP), IMX541 (20MP) and IMX542 (16MP) that run at up to 52fps.

The latest Pregius S sensors use a stacked pixel technology to reduce size and increase performance. Sony's generational sensor improvements continue to benefit image quality and applicability for a very wide range of applications and none more so than embedded applications.

The key to the latest design improvements in Pregius S sensors are Sony's proprietary Global Shutter function and the fact that the Pregius S sensors have a back-illuminated pixel structure. Previously all back-side illuminated CMOS sensors have been rolling shutter. By altering the memory area position and shifting the associated wiring, Sony gained an advantage that then allowed them to further alter the architecture of the CMOS sensor. These changes allow the pixel size to be reduced by 40% while boosting performance by more than 165%.

Earlier sensors in the Pregius line are front-side illuminated. Charged particles created in the photodiode are stored right next to the photodiode to minimise charge shift delays, to avoid image distortion and prevent light leakage. However metal pads and wiring created occlusions for the photodiode, limiting the light collecting area (and so sensitivity) as well as limiting well depth and therefore dynamic range. This in turn created saturation problems as well as limiting the miniaturisation of the pixel and sensor.

The Pregius S sensors have back-illuminated structure where the metal pads and wiring are placed behind the photodiodes. With the occlusions removed it allowed Sony to reduce pixels from 3.45µm in their Generation 3 sensors to 2.74µm in these 4th generations sensors and yet maintain the sensitivity, saturation quality and increase the resolution for the same size sensor. The reduced pixel size and increase in resolution allows the Pregius S to fit 20MP into the same sensor size that previously only fit 12MP. At the same time they increased Quantum Efficiency by 20%, saturation signal volume per unit area by 44% and dynamic range by 12%.

Speed has also been improved with the new pixel structure and resulted in 2.4X faster output data rates, a significant boost in high-speed throughput. Industrial applications benefit from performing product inspections at wider fields of view with increased accuracy and shorter measurement periods.

One of the yet unrealised benefits of the new pixel structure is the future ability for Sony to add signal processing circuits to improve sensor performance further and to add functions like smart ROI, self-trigger, compression processing. Further miniaturising the camera and capture system.

A very welcome side effect from the reduced pixel size is the reduction in cost of the per megapixel resolution of the sensor and subsequently the camera. One camera can now replace two further reducing cost. Higher resolution can also mean the ability for the camera to detect smaller details and so supports the trend to miniaturisation.

Sony have also taken specific application markets into account when designing the aspect ratio of their new sensors. The 16:9 sensors are suited to many applications including Traffic and Transportation. The 1:1 aspect ratio sensors are more suited for Medical and Life Science Applications e.g. microscopy and 4:3 aspect ratio sensors provide maximum resolution at the C-mount limit.

For more information about cameras with Sony Pregius S sensors please contact the team at Adept Turnkey