Compact sensors that can produce outstanding image quality are more needed than ever in developing sectors. Reducing Pixel Size allows companies to innovate at a never-before-seen rate in a variety of fields, including consumer electronics, industrial automation, and medical imaging. However, how might lower pixels be used to produce images of higher quality? This blog examines the developments in sensor designs, including Front Side Illumination (FSI), Back Side Illumination (BSI), and BSI-II, that are transforming imaging systems and their business consequences.
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Understanding Pixel Size and Well Capacity
A pixel is the smallest element on a sensor that converts light energy (photons) into electrical signals (electrons). The size of each pixel determines the amount of light it can capture during exposure. Larger pixels accept more photons, resulting in better image quality, particularly in low-light conditions.
However, as industries demand compact designs and higher resolutions, the push to reduce Pixel Size has driven innovations in sensor architecture. These advancements allow smaller pixels to deliver exceptional performance without compromising image quality.
One major factor in pixel performance is “full well capacity,” which refers to the maximum electrical charge a pixel can hold. Full well capacity directly influences the dynamic range of an image, determining how well the sensor captures details in both bright and dark areas. For businesses, this means better imaging for applications requiring precision, such as medical diagnostics or autonomous systems.
The Role of Sensor Architectures in Reducing Pixel Size
Reducing Pixel Size is closely tied to the evolution of sensor architectures, particularly FSI, BSI, and BSI-II. These architectures determine how efficiently a sensor can capture and utilize light, directly impacting performance.
Front Side Illumination (FSI)
In FSI sensors, light falls on the front side of the substrate, where the active pixel area is interspersed with circuitry for charge transfer and sensor operation. This design results in significant photon loss, as only a portion of the light reaches the active pixel area. Consequently, FSI sensors require larger pixels to capture sufficient light, which increases sensor size.
For businesses, the limitations of FSI mean that they are less suited for applications requiring compact designs or high resolutions.
Back Side Illumination (BSI)
BSI sensors introduced a breakthrough by flipping the sensor architecture. In BSI, light falls on the back side of the substrate, bypassing inactive regions and directly hitting the active pixel area. This design significantly reduces photon loss, allowing smaller pixels to achieve the same or even better performance than larger pixels in FSI.
With BSI, Pixel Size has been reduced to as small as 1.1μm, making it ideal for industries requiring compact sensors with high sensitivity. For instance, smartphone manufacturers leverage BSI technology to deliver exceptional image quality in compact devices.
Back Side Illumination II (BSI-II)
BSI-II builds on the advantages of BSI by enhancing the pixel’s well depth. This improvement allows for better dynamic range and greater responsivity even at the same Pixel Size. Industries like surveillance and healthcare benefit from BSI-II sensors, as they enable sharper, more detailed images in challenging lighting conditions.
Microlenses: Enhancing Pixel Efficiency
Reducing Pixel Size alone isn’t enough to maintain image quality; additional innovations like microlenses play a major role. Microlenses are arrays designed on top of the sensor to focus light directly onto the active pixel area. By improving light collection efficiency, microlenses compensate for the reduced photon capture area in smaller pixels.
For businesses, this translates to better image quality in compact sensors, enabling applications like advanced driver-assistance systems (ADAS) or precision robotics, where high accuracy is essential.
Applications of FSI, BSI, and BSI-II Sensors
The impact of reducing Pixel Size goes beyond technical advancements; it drives innovation across industries. Below are examples of sensors and their practical applications:
FSI Sensors (e.g., OV5640 from Omnivision): Suitable for cost-sensitive applications where compactness is less, such as industrial cameras.
BSI Sensors (e.g., AR0330, AR0230 from On Semiconductor): Widely used in consumer electronics like smartphones and security cameras, delivering excellent low-light performance.
BSI-II Sensors (e.g., AR1335, AR1337 from On Semiconductor): Preferred for high-end applications like medical imaging and automotive systems, where dynamic range and precision are paramount.
By leveraging these advancements, businesses can access cutting-edge imaging solutions tailored to their specific needs.
Why Pixel Size Matters to Businesses
Reducing Pixel Size offers several advantages for businesses across sectors:
Compact Designs: Smaller sensors enable more compact devices, meeting the growing demand for miniaturization in wearables, drones, and IoT devices.
Cost Efficiency: Smaller sensors often reduce manufacturing costs, enabling businesses to develop cost-effective imaging solutions.
Enhanced Performance: Technologies like BSI-II ensure exceptional performance even in low-light conditions, essential for applications like surveillance or healthcare diagnostics.
For businesses, investing in sensors with reduced Pixel Size opens the door to innovation and competitive differentiation.
Learn how to optimize Pixel Size for better image quality and enhance your embedded systems with our Vision Engineering services.
The Future of Imaging: Smaller Pixels, Smarter Solutions
The future of imaging will bring even smaller Pixel Sizes with enhanced performance through multi-layer sensors, advanced materials, and AI-driven image processing. These innovations will enable breakthrough solutions in autonomous vehicles, precision medicine, and smart cities. At Regami Solutions, we're dedicated to helping businesses leverage these next-gen technologies for continued innovation.