Patent ID: 6040577
Filing Date: 2000-03-21
Classification: G01J,H04N

Abstract:
A thermal sensor array for providing signals representative of the amount of thermal radiation in each of separate area portions of a scene producing thermal radiation which is incident upon the thermal sensor array, the array comprising:a multiplicity of thermal-radiation-sensing pixel elements, the elements being sufficiently thermally isolated among and between each other so that each element comes to an equilibrium temperature that is proportional to thermal radiation incident upon the element from an associated portion of the scene, each element serving to produce an electrical signal in proportion to its temperature;means for applying a heat pulse to each of the multiplicity of elements so that each element is momentarily driven to a new and higher temperature during the course of which change in temperature an electrical signal is produced;wherein when heat pulses are applied to elements each at a different equilibrium temperature then the magnitudes of the electrical signal produced by each will vary in accordance with this difference;wherein variations in temperature within the scene and in the separate area portions thereof are deducible from these differences, and are not required to be deduced from variations in the signal output of each of the elements at each of plural temperatures as is characteristic of conventional thermal sensor array where the electrical signals produced by the multiplicity of elements within the array are from time to time unrelated to temperature within the scene.