History of Thermal Imaging
Current thermal imagers are based on technology that was originally developed for the military. Thermal imaging technology provides the ability to see and target opposing forces through the dark of night or across a smoke-covered battleground. The properties that have made infrared detection valuable to military services around the world also make it valuable to fire services and law enforcement.
In the late 1950s and 1960s, Texas Instruments, Hughes Aircraft, and Honeywell developed single element detectors that scanned scenes and produced line images. The military had a lock on the technology because it was expensive and had sensitive military applications. These basic detectors led to the development of modern thermal imaging. The pyroelectric vidicon tube was developed by Philips and EEV in the 1970s and became the core of a new product for firefighting, first used by the Royal Navy for shipboard firefighting.
In 1978, Raytheon R&D group, then part of Texas Instruments, patented ferroelectric infrared detectors, using barium strontium titanate (BST). BST stands for barium strontium titanate, the material that coats the thermal imager’s sensor. Raytheon first demonstrated the technology to the military in 1979. In the late 1980s, the federal government awarded HIDAD (HIgh-Density Array Development) contracts to both Raytheon and Honeywell for the development of thermal imaging technology for practical military applications. Raytheon went on to commercialize BST technology, while Honeywell developed vanadium oxide (VOx) microbolometer technology. Later federal programs such as LOCUSP (Low Cost Uncooled Sensor Program) provided funding for both companies to develop their thermal imaging technologies into equipment systems, including rifle sites and drivers’ viewers. After the 1991 Gulf War, production volumes increased and costs decreased, and so introduction of thermal imaging to the fire service ensued. In late 2004, Raytheon’s Commercial Infrared Division was sold to L-3 Communications.
Meanwhile, the Honeywell microbolometer patent was awarded in 1994. Boeing, Lockheed-Martin (who sold its infrared business to British Aerospace, or BAE), and others licensed VOx technology from Honeywell and developed infrared detectors for military applications. Thermal imagers based on both BST and microbolometer technologies are available now for non-military applications. In fact, thermal imaging has now expanded to be used in firefighting, law enforcement, industrial applications, security, transportation and many other industries. Bullard introduced it’s first thermal imager specifically designed for fire fighting in 1998.