Patent ID: 8592765

Claim:
Thermal infrared sensor in a housing with optics and a sensor chip having at least one sensor cell producing a signal voltage proportional to a temperature difference between hot and cold contacts of a thermopile sensor structure, comprising: a membrane spanning a heat conducting frame-shaped support body, wherein the support body has vertical or approximately vertical walls, and is completely hollowed out beneath the membrane; a thermopile sensor structure including a few long thermocouples per sensor cell, said thermocouples being arranged on connecting webs that connect together hot contacts on an absorber layer on the membrane to cold contacts of the thermocouples on the support body along indirect paths; wherein the membrane is suspended by one or more of the connecting webs; the membrane has, on both sides of the long thermocouples, narrow slits that separate the connecting webs from both a central region of the membrane and also from the support body; at least the central region of the membrane is covered by the absorber layer; and the sensor cell is filled with a gas having a thermal heat conductivity at normal atmospheric pressure significantly lower than air or nitrogen.