Patent ID: 8182142

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 split 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 to provide a reflected reference beam; an optical path length adjuster for adjusting an optical path length of the reflected reference beam reflected from the reference beam reflector; a reference beam transmitting member for transmitting the split reference beam coming from the first splitter to a reference beam irradiation position from which the split 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 reflected 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; and an attenuator that attenuates the split reference beam coming from the first splitter and the reflected reference beam reflected from the reference beam reflector such that an intensity of the attenuated reflected reference beam becomes closer to an intensity of the measurement beam reflected from the temperature measurement object, wherein the attenuator attenuates the split and the reflected reference beam passing therethrough to 1/√{square root over (n)} of an original intensity thereof.