By James DeRuvo (doddleNEWS)
It’s called the “Exmor RS,” and Sony is hailing it as the World’s First*1 Stacked CMOS Image Sensor. Stacked? What the heck does that mean? It means that researchers are doing for camera censors what computer chip designers discovered a few years ago, that two chips are better than one, but with the added bonus that stacking them leads to greater image quality, with lower file sizes.
The “Exmor RS” is a CMOS image sensor that adopts a unique ‘stacked structure.’ This structure layers the pixel section, containing formations of back-illuminated pixels over the chip affixed with mounted circuits for signal processing, in place of conventional supporting substrates used for back-illuminated CMOS image sensors. – Sony News Release
The new stack CMOS sensor will be featured in three different configurations and are designed chiefly to be used in Smartphones and Tablets. The sensors will provide either 8.08 megapixels or 13.13 megapixels and will use an encoding technique called ‘RGBW coding’ for still images and ‘HDR (High Dynamic Range) movie’ for video.
Sony says that RGBW will boost low light image capture thanks to a white pixel encoding which will seek out and enhance brighter lighting conditions in the low light spectrum. High Dynamic Range Movie will take two images simultaneously but at different exposures and then sandwich them for each frame, creating a more detailed and color accurate video image.
“Exmor RS” stacked CMOS image sensor
2) This stacked structure facilitates higher image quality, advanced functionality and a more compact size.
– Equipped with ‘RGBW coding’ and ‘HDR movie’ functions (“IMX135” and “IMX134”)
– Equipped with a built-in camera signal processing function, enabling compatibility with automatic controls, picture adjustment and multiple image output formats (such as YUV) (“ISX014”)
Imaging modules (each image sensor is mounted with a built-in lens unit with auto-focus mechanism):
1) High resolution has been achieved by adopting a newly-designed lens, which is optimized for the industry’s smallest(*1) 1.12μm unit pixel size.
2) The “IU135F3-Z” auto-focus lens module adopts a bright F2.2 high-resolution lens.
3) The “IU134F9-Z” achieves a thin, compact size (W:8.5 x D:8.5 x H:4.2mm(*4)).
4) The “IUS014F-Z” is an all-in-one model capable of picture adjustment that comes equipped with a camera signal processing function.
Sony is also building new auto focus image modules which will work in concert with the new CMOS sensors to provide the light gathering capability of a high-resolution F2.2 lens.
And while SONY will continue to manufacture standard RGB CMOS censors, they believe that the stacked configuration to be the future and will be focusing on it’s development moving forward because it provides additional image quality without having to enlarge the camera sensor. And since real estate is at a premium in smartphone design, it’s bound to be quickly adopted by manufacturers when it ships in 2013 in a phased roll out that begins with the 13.13 megapixel censor, followed by the pair of smaller 8.08 censors which will be out by year’s end.