Patent ID: 8764288

Claim:
A temperature measuring apparatus comprising: a light source; a first splitter for dividing a light beam emanated from the light source into a measurement beam and a reference beam; at least one second splitter for dividing the measurement beam coming from the first splitter into a first to an nth measuring beam; a reference beam reflector for reflecting the reference beam coming from the first splitter; an optical path length adjuster for adjusting an optical path length of the reference beam reflected from the reference beam reflector; a reference beam transmitting member for transmitting the reference beam coming from the first splitter to a reference beam irradiation position from which the reference beam is irradiated onto the reference beam reflector; a first to an nth measuring beam transmitting member for transmitting the first to the nth measuring beam coming from the second splitters to measuring beam irradiating positions from which the measurement beams are irradiated onto a first to an nth measurement points of a temperature measurement object; a photodetector for measuring an interference between the reference beam reflected from the reference beam reflector and the first to the nth measuring beam reflected from the temperature measurement object, wherein the optical path lengths of the first to the nth measuring beam from the second splitter to the temperature measurement object are different from each other; an AC component extractor that extracts an AC component from an output signal of the photodetector: and a switch for switching the AC component extractor between a first state where the AC component is extracted by the AC component extractor and a second state where the total output signal of the photodetector passes through the AC component extractor.