The technology advances of CMOS image sensors are unstoppable, literally. After redefining mobile phone designs for more than a decade, they have reached the doorsteps of artificial intelligence (AI) applications such as machine vision, object detection and recognition, and deep learning.
The availability of global shutter image sensors providing clear, sharp images at 4K camera resolutions is opening doors to new uses cases including 3D modeling, agricultural drones, industrial automation, and robotics. Agricultural drones, for example, capture high-resolution color images of crops and perform field monitoring in real-time.
Fig. 1: The new CMOS image sensors from Teledyne e2v (left) and SmartSens are eyeing machine-vision applications in intelligent traffic systems, drones, and smart barcode readers. Images: Teledyne e2v (left) and SmartSens Technology (right).
The breakthroughs in CMOS image sensor technology are enabling new camera designs for highly demanding machine-vision applications. And that’s allowing developers to replace the expensive charge-coupled device (CCD)-based image sensors, which have traditionally been used in applications requiring ultra-high resolution.
According to a recent study from IC Insights, CMOS image sensors continue to grab market share from CCDs, increasing their market share to 89% in 2017 from 74% in 2012. The market research firm also projects that 45% of CMOS image sensor consumption will come from applications other than camera phones.
That includes next-generation camera designs serving new use cases like augmented reality and virtual reality. Then there are object detection and recognition applications in advanced driver assistance systems (ADAS) and autonomous vehicle designs that are integrating CMOS image sensors and machine-vision algorithms on the same chip. The IC Insights study also forecasts that CMOS image sensors will experience the fastest growth in automotive designs during the 2017 to 2022 period.
New CMOS image sensor designs are enabling advanced digital imaging solutions in consumer and industrial machine-vision applications. Major advances in CMOS image technology include new pixel architectures, while many of these devices are integrating more functions to facilitate AI applications such as facial recognition and gesture control.
Evolution of pixel architecture
A wide range of customizable pixel architectures is bringing new dimensions into next-generation camera designs. These new structures offer a smaller optical format and faster photoelectric conversion and signal-readout functions.
A new breed of CMOS image sensors also provides more detailed views of a larger object surface, a critical requirement in industrial automation applications such as automated optical inspection (AOI) of displays in mobile phones, tablets, laptops, and TVs.
Fig. 2: OmniVision’s CMOS image sensors aim to boost pixel performance within the same optical format. Image: OmniVision Technologies, Inc.
But what makes these image sensors ready for vision-system–based automated inspection? What are the key enablers? Here is a sneak peek of the key features driving the transformation of CMOS image sensors and how they enable these devices to serve new use cases in the machine-vision realm.