| 摘要 |
PURPOSE:To suppress the variance in luminous brightness by combining a light emitting element having a higher luminous efficiency and a light emitting element having a lower luminous efficiency so as to constitute the titled luminous device. CONSTITUTION:The luminous device 1 is formed by the light emitting element A having a higher luminous efficiency and a light emitting element B having a lower luminous efficiency and the light irradiated from the device 1 is received by a photodetector 2. In selecting the variance in the luminous efficiency of the light emitting element A as 20-100(mW/sr) in the irradiated strength and selecting the variance in the luminous efficiency of the light emitting element B as 101-200(mW/sr), then there is a difference in 200-20(mW/sr), that is, ten times, between the luminous devices having the highest luminous efficiency and the lowest luminous efficiency. Thus, in using the light emitting element A having the higher luminous efficiency and the light emitting element B having the lower luminous efficiency in combination, then A+B=121-300(mW/sr), that is, 300/121=nearly 2.5 times at maximum in difference is attained to suppress the variance in the luminous brightness. |
