LIGHT RECEPTION/LIGHT EMITTING DEVICE AND DENSITY MEASUREMENT DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a light reception/light emitting device and a density measurement device that enable more accurate detection of a spatial state during a period of time from a light emitting unit to a sensor unit.SOLUTION: A light reception/light emitting device comprises: a first substrate 21; a second substrate 22; and a light reception/light emittance control unit 30 that supplies electric power to a first light emitting unit 1 and a second light emitting unit 2, and detects output signals from a first sensor unit 11 and a second sensor unit 12. The first sensor unit 11 is arranged at a position upon which light reflected upon a second principal face of the first substrate 21 of light outputted from the first light emitting unit 1 is incident, and the second sensor unit 12 is arranged at a position upon which light reflected upon a second principal face of the second substrate 22 of light outputted from the second light emitting unit 2 is incident. The light reception/light emittance control unit 30 is configured to control the electric power to be supplied to the first light emitting unit 1 and the electric power to be supplied to the second light emitting unit 2 so that a temperature difference between the first sensor unit 11 and the second sensor unit 12 is made constant without relying on an ambient temperature.SELECTED DRAWING: Figure 1