April 20, 2007, Cambridge, England--Thermoteknix has launched what it says is the world's first alpha-silicon-based focal-plane-array (FPA) thermal-imaging camera with shutterless technology. The Miricle 110KS is an ultracompact uncooled (unstabilized) solid-state high-resolution infrared camera delivering what the company calls "never blind" thermal imaging. The camera has no shutter or moving parts.
Shutterless operation has been considered the holy grail of the FPA industry and a seemingly technically impossible goal for those involved in the thermal-imaging world, according to Thermoteknix. Until now, the current generation of FPA based cameras has required frequent shuttered calibration blanking off the incoming image with a "shutter" or "flag" and rendering the observer blind to the scene for several seconds at a time. In critical situations such as target tracking, online machine vision, or weapon-based applications, this complete obstruction to vision could be inconvenient and even dangerous.
Each element in the FPA detector possesses a different gain and offset value that require continuous adjustment to present a uniform image. Many factors, including external ambient temperature, drift, and the temperature of the detector itself, lead to a fundamental fixed-pattern noise in the detector output. This leads to steady deterioration of image quality over time. Traditional cameras address this issue by regularly interposing a uniform surface in front of the detector--typically a mechanically driven shutter or flag that blocks all radiation from the scene and performs a non-uniformity correction (NUC). This "shuttered" or "blinkered" approach, although being quite effective, has several major problems associated with it:
--vision is interrupted while the detector is calibrated, which can take several seconds
--additional size, weight, and unreliability of a mechanical shutter
--acoustic noise generated by the shutter opening and closing
--additional power required to operate the shutter
--added design complexity and susceptibility to wear and jamming
Thermoteknix designed its camera with what it calls "XTi" technology. Based on a 384 x 288 pixel alpha (amorphous) silicon microbolometer with a 7 to 14 µm spectral range, the lightweight, ruggedized thermal imaging device powers up with no lag and provides continuous, uncooled digital thermal imaging.