New Samsung sensor heats up the megapixel race

TAIPEI,TAIWAN—On March 27, Samsung Electronics announced an 8.4 megapixel (Mp) CMOS image sensor with a 1.

TAIPEI,TAIWAN—On March 27, Samsung Electronics announced an 8.4 megapixel (Mp) CMOS image sensor with a 1.4 mm pixel design at Samsung’s fourth annual Mobile Solution Forum. The new image sensor chip, which Samsung calls the “world’s smallest,” provides a high signalto-noise ratio—a key measure of overall image quality. Advanced light-sensing features and minimized noise levels helped the company achieve the high resolution. Also, the company implemented “extended photodiode technology” to achieve higher light sensitivity and saturation levels, resulting in an enhanced fill factor.

Furthermore, the sensor provides the same image quality as the charge-coupled-device (CCD) image sensors currently used in most digital cameras and camcorders. Since the new sensor only uses one-tenth the power of a CCD image sensor, Samsung expects it to quickly replace CCDs in all three key applications—mobile phones, digital cameras, and camcorders.

The CMOS image sensor product line of Samsung’s System LSI division is one of the five major product areas that the company has been focusing on to enhance and balance the company’s overall competitiveness. Samsung’s present portfolio of imaging sensor technology spans the range of 1.3 through 5 Mp resolution with the 8 Mp capability expected to be available in the second half of 2008.

The “world’s first” claim by Samsung of 8.4 Mp at 1.4 mm pixel sizes seems to one-up Kodak’s recent 5 Mp sensor in both pixel density and size (see www.laserfocusworld.com/articles/319336 and Optoelectronics Report, March 15, 2008, p. 3). But Kodak is keeping the announcement in perspective.

Commenting on the Samsung buzz, Kodak executive Fas Mosleh says the development is good for the industry. “It is great that the industry continues to introduce new products at higher resolution. The 8 Mp was first introduced by another player in 2006 [Micron Technology] and now Samsung has an 8.4.We believe 8 Mp will go into some higher-end phones but will not be mainstream for a while yet.”

Becoming mainstream may take some time for 8 Mp, because the race for more megapixels does not mean a race for better quality. “Consumers may equate more megapixels to better quality,” says Mosleh. “But it also means smaller pixels, which take in less light and create poorer, low-light pictures. So megapixels are going up, and image quality, paradoxically, is dropping.”

Higher resolution images also require more memory and a larger databus architecture inside the device. This means greater cost and more expensive phones. Eran Kali, VP of marketing at optical zoom company Tessera’s Smart Optics division (Tel Aviv, Israel), agrees that more megapixels are not necessarily a good thing. “There’s an issue with transmitting so much data. If you could put a 100 Mp camera with 64-bit depth into a cell phone, would you want to? It’s not clear. The product is driven by what the marketers want to sell, not what the users want.”

The imaging sensor market is expected to show high demand for highresolution devices. According to Samsung, the current outlook toward 2009 shows a compound annual growth rate of over 90% for devices of 3 Mp and higher resolution over a four-year term from 2006 through 2009.

—Valerie Coffey

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