Omnivision builds image sensor with 1.1-micron pixels
Image sensor manufacturer Omnivision has developed a new image sensor with a pixel size of only 1.1 microns. The 1/4″ cmos sensor shoots images at eight megapixels and fits into an 8.5×8.5×4.7mm camera module.
The OV8550 image sensor makes using Ominivision’s new OmniBSI-2 pixel architecture. This one has a pixel size of 1.1 microns, compared to 1.4 microns for the previous generation. Both OmniBSI and OmniBSI-2 apply the principle of backside illumination: the wiring layers are located behind the photodiodes, so that they can receive more light. According to Omnivision, the new sensor and the new pixel architecture make it possible to shrink mobiles even further.
Although smaller pixels are in principle less light-sensitive, the technical improvements would ensure that the image quality has not deteriorated. For example, the OmniBSI-2 pixel architecture would be twenty percent more efficient in all color channels and the light sensitivity would have increased by 35 percent in low light. Omnivision also says it has increased the full well capacity of the pixels by 45 percent. That is an indication of the dynamic range of a sensor.
The sensor is equipped with an integrated temperature sensor. The new chip can also expose the even and odd pixel rows separately for HDR recordings. Furthermore, the so-called OV8550 supports 1080/30p video and it is possible to record 720/60p video with electronic image stabilization via so-called binning of pixels.
The first samples of the OV8850 will be available in August and mass production will start in the first quarter of 2012. Omnivision is, among other things, the supplier of the camera in the iPhone 4.
The competition is on Omnivision’s heels: Aptina among others works also to sensors with 1.1-micron pixels. That company already showed its pixel technology at the Mobile World Congress that was held in Barcelona earlier this year. Aptina would make the first sensor samples based on this technology available this year.