| 摘要 |
PURPOSE:To enable to vary emitting light color of high speed by applying the electric inputs of junctions of composite light emitting diodes at the time division ratio of the maximum allowable input current time product of the diodes, thereby controlling the mixture ratio of the emitting light amounts of different wavelengths. CONSTITUTION:Composite LEDs 1 have three junctions J1, J2, J3 for emitting red, green and blue, and are operated to emit lights via drive input pulse currents ip1, ip2, ip3. In the relationship represented by the maximum input power P per unit time allowable at the continuous light emitting time, P=(IP<2>TP)NR, the maximum input current IP and the maximum input pulse width TP are preset. However, N indicates the number of pulses repeated during the unit time T, and R indicates a proportional constant, and a symbol in ( ) represents the current time product. The apparent emitting light colors of the composite LEDs 1 vary by the ratio of the input pulse widths t1, t2, t3 (TP=t1+t2+t3) time-divided from the input pulse currents ip1, ip2, ip3. |
