Patent ID: 8369913

Claim:
An optical measurement instrument for a living body, the instrument comprising: a light source adapted to emit a plurality of optical signals to the surface of a living body; and a light-receiving device that detects the plurality of optical signals emitted from a surface of the living body after the optical signals have passed through an interior of the living body, wherein the light source includes a plurality of semiconductor light-emitting devices having mutually different wavelengths from the visible to the infrared mounted on a sub-mount, a driving circuit connected to the plurality of semiconductor light-emitting devices that controls output of the optical signals and emits optical signals of different wavelengths, and one optical output power monitoring device that detects the optical signals emitted from the plurality of semiconductor light-emitting devices, these elements being housed in one package, the output of the optical signals by the plurality of semiconductor light-emitting devices is controlled by feeding power output signals corresponding to the plurality of optical signals detected by the optical output power monitoring device back to the driving circuit connected to the semiconductor light-emitting devices that emit the optical signals of different wavelengths, a signal separation circuit that receives the power output signals and separates the power output signals for each wavelength of the plurality of optical signals corresponding to the power output signals, and the output of the optical signals is controlled to remain constant according to the power output signals separated by the signal separation circuit.