Advantages
CMOS image sensors have improved by leaps over the last few years. Resolutions are now high enough and run at fast enough frame rates to enable advanced-camera features like electronic pan, tilt, and zoom or image stabilization. CMOS architecture allows for random pixel access and window-of-interest readout for applications requiring image compression, motion detection, or target tracking.
CMOS imagers are now designed in to generations of DSCs, IP security cameras, and even intelligent vehicle systems. Their portability and low power consumption have driven these sensors to dominance in markets like mobile handset camera systems; digital SLRs; and high-speed, machine-vision cameras. |
|
Features
High dynamic range
High dynamic range sensors capture complete scene information, enabling sophisticated processing applications.
Low-light and near-IR sensitivity
Acutely sensitive or near-IR sensors perform in very low-light, capturing seemingly obscured details.
High speed
Speedy sensors running at fast frame rates open up a new world of advanced features like burst modes and improve standard features like auto focus.
Industrial temp
Industrial temperature sensors function in extreme conditions ranging from –40°C to +125°C. |
Visual aesthetics and the image signal processor
There are times when a beautiful image is exactly what your eye sees, but more often a beautiful image is what your mind’s eye sees. To put it bluntly, life–real life–has warts, blotches, and stains. The sky really isn’t the color blue you remember, and the camera can add 10 pounds.
But fear not, we have a solution. We employ advanced, precedent-setting algorithms to manage everything from color saturation and white balance to noise reduction and dark current. We stabilize images and blast the blurry. We help ensure beautiful pictures in virtually any scenario, and we do it with flexible image signal processors and all-in-one system-on-chip (SOC) solutions.
SOCs and ISPs improve the picture you see
Digital image signal processors (ISPs) and SOCs use algorithms, or well-defined step-by-step instructions, to adjust the raw data an image sensor collects so that the processed image or video is more visually pleasing than the original. Put another way, SOCs and ISPs make the image look more like what the mind’s eye sees, eliminating image blemishes, compensating for poor lighting conditions, or even correcting for a shaky hand or for bad focus.
The process is the kind of magic that can’t be left to an acolyte or imaging neophyte. Good image correction is the result of years of experience and innovation. It requires a precise understanding of how light energy is converted into digital signals, and it requires an intuitive aesthetic. We’ve been doing and experimenting with image processing for more than a decade. We have the experience and the artfulness to process great images and video. And our experience helped us offer one of the industry’s first SOCs and lead the way with companion chip digital image signal processors.
SOCs — powerful processing on a single chip
SOCs, which are built right on to the image sensor at the silicon level, have several key advantages. They’re designed to work perfectly with the sensor they are attached to, so the SOC’s signal processing is at its best when the sensor is the most challenged. They’re a compact, one-chip solution, making them easy to integrate, which can potentially lower overall system cost.
More SOCs and ISPs to come
Digital images and video have sparked a revolution in both consumer electronics and social interaction. Virtually everywhere on Earth people are taking photos with their camera phones, digital still cameras, or web cams and sharing the resulting images on YouTube, Flickr, Facebook, or MySpace. They are emailing images, printing images, and sharing those images every moment of every day.
Analysts expect consumers to purchase more than one billion camera phones each year by 2010. More than half of those mobile handsets will have two cameras each, essentially requiring a companion chip or SOC solution. |
|
Growing sensor market
CMOS image sensor applications are growing at a phenomenal rate by the year. According to a 2007 IDC study, the fastest-growing areas are in DSCs, DVCs, PC cameras, and camera phones. Consumers are demanding more functionality, including advanced and robust video capabilities on DSCs and camera phones. As far as future growth projections go, IDC has also forecasted that camera phone shipments will reach 1 billion by 2010 and every one of them will have a CMOS sensor (or two) in them.
Aptina image sensor expertise
The quality of a CMOS sensor equals the level of quality you get in an imaging solution and our sensor expertise means you have all the advantages. We have been studying and developing CMOS sensors for over a decade now, beginning when NASA’s Dr. Eric Fossum researched what advantages CMOS image sensors had. And they did have advantages, including less power requirements, more portability, and miniaturized imaging systems.
In 1995, Dr. Fossum co-founded Photobit Corporation to commercialize CMOS image sensors, and they became an industry leader in scientific, military, and industrial applications. In 2001, Micron Technology, a semiconductor company, acquired Photobit. They merged Photobit’s cutting-edge imagers with their own extensive memory-based manufacturing process to make world-leading CMOS sensors.
Low power that extends battery life
CMOS sensors consume up to 100X less power than CCDs. Because CCDs are essentially capacitive devices, they need external control signals and large clock swings to achieve acceptable charge transfer efficiencies. Their off-chip support circuitry dissipates significant power. CCD systems require numerous power supplies and voltage regulators for operation, whereas CMOS sensors use a single low-voltage supply. Think about this: a CMOS digital camera system operating from a NiCd camcorder battery could operate for a week, while a CCD arrangement could drain the battery in a few hours.
Random access to pixel regions of interest adds flexibility
In CMOS sensors, both the photodetector and the readout amplifier are part of each pixel. This enables the integrated charge to be converted into a voltage inside the pixel, which can then be read out over X-Y wires (instead of using a charge domain shift register, as in CCDs). This capability can be used for on-chip electronic pan, tilt, and zoom. Windowing provides added flexibility in applications that need image compression, motion detection, or target tracking.
No artifacts, smear, or blooming means higher-quality images
CMOS architectures use intra-pixel amplification in conjunction with both temporal and fixed-pattern noise suppression circuitry (correlated double sampling), which produces exceptional imagery in terms of dynamic range (a wide ~120dB) and noise. CMOS sensors also have built-in anti-blooming protection in each pixel. |