"Previous sensor technology developments focused on improving the light absorption of each pixel, and have progressed pixel technology from FSI (Front Side Illumination) to BSI (Back Side Illumination) which places photodiode at the top to maximize photoelectric efficiency. While being very effective at the time, this BSI technology also faced limitations in improving image quality as pixel sizes continued to decrease.
Building on these past advances and continuing the push toward higher quality image sensors for mobile devices, Samsung has developed ISOCELL the next generation of pixel technology, which is patent pending. ISOCELL technology forms a physical barrier between neighboring pixels – isolating the pixel. This isolation enables more photons to be collected from the micro-lens and absorbed into the correct pixel’s photodiode minimizing undesired electrical crosstalk between pixels and allowing expanded full well capacity (FWC).
Compared to conventional BSI pixels, the ISOCELL pixels decrease the crosstalk by approximately 30 percent which results in higher color fidelity to reproduce the original color with sharpness and richness, and increase the full well capacity (FWC) by 30 percent which leads to greater dynamic range.
Additionally, an imager designed with ISOCELL can feature a 20 percent wider chief ray angle (CRA), reducing the height of the camera module. This makes it suitable for slim and small form factor mobile devices with challenging low z-height requirements.
As the first Samsung image sensor to adopt this new technology, the S5K4H5YB 8Megapixel imager utilizes a 1.12um ISOCELL pixel and has a 1/4inch optical format. The S5K4H5YB is currently sampling to customers with mass production scheduled for Q4 2013.
According to market research firm Techno System Research, in 2014, approximately 66 percent of smartphones will feature image sensors with 8Mp or higher resolution."
Samsung Tomorrow, the official Samsung blog, publishes ISOCELL vs BSI comparison picture (click to expand):
Chasing quantum efficiency on every pixel increases the full well problem. Some pixels should have an ND-filter to preserve detail in high lights. I.E. One in four pixels in a bayer pattern (different color from every 2*2 color group). Rggb-rGgb-rgGb-rggB.
ReplyDeleteIs this similar to STM's DTI technology??
ReplyDeleteSounds suspiciously like deep trench isolated cells to me (First pioneered in production by ST I believe)
ReplyDeleteI'd like to find a phone with 3M pixels or less but with a larger pixel size. Back in a days (1996?) I used a digital Kodak camera that had less than 3MPs but the quality of the images was far more superior to what I had with all my 8,10 15 Mps phone cameras.
ReplyDelete