摘要 |
A thermal detector comprises a thin film diode transistor coated with infrared absorbent material, and mounted on a thermally insulating support such as silicon oxide, foam glass or foam plastics material. The support may be recessed to improve insulation. The detector may be an array of diodes or transistors, and the diodes may be LEDs. Addressing may be line-by-line or co-ordinate selection. A transistor detector array may be arranged for signal integration and sample switching. A chopper may be used to modulate radiation illuminating the detector, whose output is fed to subtractive circuitry. Alternatively, a transistor detector array may incorporate additional transistors for bias current subtraction, each detecting transistor forming a long-tailed pair configuration with a respective additional transistor. |