Image stabilization for cameraphones
According to ExtremeTech, a startup company named InvenSense has developed a MEMS gyroscope for cameraphones. This gyroscope will be integrated in new cellphones before the end of the year. These small dual-axis angular rate sensors (3.5mm x 3.5mm today and smaller soon) can provide a better image stabilization than current systems while being five times smaller. They'll do that by neutralizing the involuntary motion of our hands which vibrate at about 10 to 20 times per second. Read more...
Here is how these MEMS (Micro Electro-Mechanical Systems) gyroscopes work.
The tiny micromachines react to and counteract vibrations in a user's hand, steadying the cameraphone's lens. While bulkier gyroscopes are becoming increasingly common in standalone digital still image and video cameras, InvenSense's "Gyroscop" was created to fit within the tiny confines of a cellular phone, which is taking on the functions, and feature sets, of low-end dedicated cameras.
And they are really small (3 mm x 3 mm in the next revision) as you can see on the picture on the left of the IDG-300 model, which is a dual-axis gyroscope consisting of two independent vibratory MEMS gyroscopes. (Credit: InvenSense)
But why do we need such sensors in our cameraphones?
"The problem we're addressing is image stabilization and image quality," said Steve Nasiri[, president and chief executive of InvenSense.] "The challenge for megapixel cameraphones, as they go from 1.2 megapixels up to 3 megapixels and higher resolutions, is picture blurriness, and it gets more severe with the digital cameras mounted in cell phones."
According to Nasiri, blurriness occurs not as a user moves the camera in a plane, but jitters it up and down, due to involuntary muscle movement. The human hand vibrates at about 10 to 20 times per second (10-20 Hertz) and, according to Nasiri, requires a gyroscopic sensor capable of sensing 150 Hertz to be able to detect and filter out the noise of the moving hand.
And Nasiri added that these gyroscopes, which will be shipped this fall, should prevent your next 3-Mpixel cameraphone to become "a 1-Mpixel clunker."
For more information, you should check this compilation of papers gathered by InvenSense on the subject.
Sources: Mark Hachman, ExtremeTech, May 25, 2006; and InvenSense web site
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