Thermal sensor distinguishes between humans, other heat sources
Designed with a high pixel count (80×32 pixels) for security and smart building applications, the Mitsubishi Electric Diode InfraRed sensor (MelDIR) relies on thermal diode infrared sensor technology the company developed for the Advanced Land Observing Satellite-2 “DAICHI-2” (ALOS-2).
Compared to today’s 16×16 pixel thermopile sensors, the device offers 10 times higher pixel resolution and five times higher thermal resolution at 100mK, or 0.1 degree Celsius. Each thermal diode (or sensor pixel) is supported by microfabricated legs that convey energy efficiently without releasing heat, enabling more pixels to be used for increased resolution.
Electrical noise is minimized by mounting the thermal diodes and high-spec amplifiers close to each other on the same chip, helping to maintain accuracy and achieve high thermal resolution. The detailed infrared images make it possible to distinguish between humans and other heat sources as well as to identify specific behaviour.
Measuring 19.5×13.5×9.5mm, the device comes in a package 80 percent smaller than that of existing sensors, it boasts a 78º x 29º field of view and has a detectable temperature range of -5 to +60ºC. Mitsubishi Electric used a proprietary chip-scale packaging and vacuum-sealing technology to ensure the sensor is vacuum sealed (without using conventional ceramic package) to avoid heat radiation and achieve high thermal resolution.
Mitsubishi Electric – www.MitsubishiElectric.com