Image Sensor Developments Usher in the Future of Imaging
POSTED 12/18/2023 | By: John Butler, Contributing Editor, Tech B2B Marketing
In the fast-advancing world of industrial imaging, robotics, and autonomous platforms, image sensors have become a major force in reshaping how we perceive and interact with the world. These often small devices play a crucial role in capturing visual information and translating it into digital data, impacting and benefiting a multitude of industries and applications across the globe.
Achievements in Sensor Evolution
Early sensor development was primarily based on charge-coupled device (CCD) technology, and while this technology remains in use today, complementary metal-oxide semiconductor (CMOS) technology has emerged as the more dominant option for many sensor developers. The shift from CCD to CMOS has been a game-changer, resulting in lower power consumption, expanded integration capabilities, and overall cost-effectiveness gains for device builders and system designers alike, thanks in part to a concentration of effort in several key areas of the technology:
- Increased Resolutions and Pixel Densities: Perhaps the most touted stride in image sensor advancement is the continuous increase in resolutions and pixel densities. Modern sensors offer the ability to capture images with unprecedented detail and outstanding visual clarity. The demand for higher resolutions has been driven by industrial inspection systems and aerial imaging and mapping platforms. Sensors are available today at resolutions exceeding 150 megapixels and contained in a package that measures approximately 60 mm diagonally.
- Miniaturization and Power Efficiency: Driven mainly by consumer demand, sensor development has focused heavily on miniaturization and reduced power consumption. In the field of smartphones, portable devices, and the Internet of Things (IoT), applications continue to thirst for more data while placing constraints on physical size and power efficiency. System-on-chip (SoC) platforms have advanced dramatically, enabling sensors to be combined with processing, memory, and other peripheral devices on a single chip. In robotics and other remote sensing applications, these breakthroughs have been vital to increased system adoption and improved performance.
- Low Light and Infrared Performance: Spectral responsivity, or a sensor’s ability to capture light, has long been a focus of sensor development. The greater the sensitivity of a sensor, the less light required and subsequently the faster an image can be acquired. In security and surveillance and in autonomous driving, these advances enable quality imaging in challenging lighting conditions, such as dusk or nighttime scenes. Back-side illumination (BSI) has been instrumental in improving responsivity. Similarly, for sensors designed to image infrared light or heat, recent advances have produced higher-resolution imagers that provide a greater level of scene information and can identify smaller defects from greater distances.
- Advanced Signal Processing: The ability to do more at the sensor level is a key development of sensor technology. Integrating advanced signal processing enables on-the-fly image processing and enhancement, and lightens the processing load on external devices. For those opportunities where low-latency or real-time imaging is critical, such as in medical imaging or autonomous vehicle navigation, on-chip processing is invaluable to enable application success.
Leveraging Sensor Development in Imaging Solutions
The milestones achieved in image sensor technology have given rise to a diverse and growing range of products that continue to push the boundaries of imaging capability. Recent advancements and innovation in 2D and 3D cameras as well as contact image sensors (CIS) stand out as game changing and have created new opportunities across industries.
2D and 3D Camera Advancements
For years, 2D cameras have been a mainstay in industrial imaging. A more recent addition to industrial imaging, 3D cameras have unlocked a mix of applications that go beyond traditional imaging. This evolution has altered the way we interact with and perceive visual information.
The primary consumers of today’s highest-resolution sensors are 2D cameras, which are paired with interfaces that enable the transfer of vast amounts of data with low, predictable latency. This produces a device that not only captures extreme detail but also does so at high speed.
Emergent Vision Technologies is a pioneer in the adoption of leading-edge sensor technology. It develops and manufactures some of the largest and most advanced 2D camera products in the industry. Emergent’s president and CEO, John Ilett, comments, “Sensor manufacturers like Sony and Gpixel continue to push image sensing forward with significant improvements in key areas like speed, image quality, and resolution.” He adds, “These advancements help push the capabilities of high-speed cameras to new heights, which drive the capabilities of machine vision and imaging systems forward.”
For applications that 2D cameras cannot handle, businesses turn to 3D cameras. In manufacturing, these cameras are used for determining fill levels in opaque containers prior to capping. In biometric applications, 3D imaging is used in authentication systems, including facial recognition, providing a precise, accurate, and secure means to verify identities. A strength of 3D technology is the ability to analyze and process scene data across a field of view. Resolutions are typically lower than those of conventional 2D products, as the value of the final product centers on its ability to visualize depth within a scene.
In autonomous vehicle applications, 3D imaging is proving its value in navigation and for providing critical data in anti-collision systems. Gerry Paci, marketing manager for material handling at Pepperl+Fuchs, says, “We now can discern differences between objects and environments that in the past would appear similar. In collision avoidance and environmental perception, these advances have made difficult applications a little easier to solve.”
Contact Image Sensors Push Forward
Another significant stride in imaging technology lies in the advancement of contact image sensors. Unlike traditional scanners, which use a moving light source and mirrors, CIS technology makes use of a stationary light source and a sensor array. This reduces complexity while improving reliability and has given way to a new class of industrial imaging products with their own advantages.
Modern CIS modules leverage CMOS sensor technology combined with lenses and lighting in a complete, deployable module. They provide high-speed image acquisition and enable ultra-high resolution in the resulting images. This technology is very well suited to digitizing documentation and to surface inspection applications, such as print inspection, printed circuit board inspection, and general machine vision applications that benefit from large-format linear imagers. Another emerging market segment for CIS products is battery foil inspection for electric vehicle (EV) batteries, representing a significant opportunity for the expansion of automated and industrial inspection.
Future Prospects and Challenges
As we look ahead, sensor technology advancement will continue to redefine imaging capabilities and will drive innovation in the form of 2D, 3D, and other imaging devices. Miniaturization of sensors, coupled with advancement in material science and evolving manufacturing processes, will almost certainly lead to more compact and efficient devices. In surveillance and consumer use, advancing imaging technologies may encounter challenges in the form of privacy concerns; those will need to be addressed responsibly in a way that ensures continued adoption.
The synergy between image sensor development and emerging products will continue to deepen. For example, immersive experience facilitated by 3D vision will impact everyday lives. The compact efficiency of contact image sensors will also unlock new applications, replacing manual inspection with robust, reliable, and consistent digital alternatives.
From automotive advancements to breakthroughs in diagnostic imaging in health care, these small devices are driving innovation and advancement that will touch our lives in profound ways. With sustained progress, we can expect continued evolution and revolution, further solidifying digital image sensors as a cornerstone of the digital age.