| 摘要 |
PURPOSE:To enable a light emitting diode to be stabilized an intensity of emitted light through a wide range of temperature by a method wherein a control circuit composed of a drive switch element and a control switch element which makes the drive switch element ON or OFF is provided inside a power circuit of the light emitting diode. CONSTITUTION:A drive transistor Tr1 is provided inside a power circuit of an LED composed of a power source E, a light emitting diode LED and a resistor R1, and concurrently a control circuit 2 composed of a control transistor Tr2, a diode array 1 consisting of two or more diodes D1-D3 connected with each other in a forward direction and a resistor R2 is provided in parallel with the power source E. The above components are so structured as to make switching of the drive switch element Tr1 corresponding to a potential of a connecting point a of the diode array 1 with the resistor R2 inside the control circuit 2, and the control voltage of the drive switch element Tr1 is made to change proportionally through temperature. By these processes, a light emitting diode can be stabilized in intensity of emitted light in a wide range of temperature as compensating the temperature change without using a special temperature compensating element. |
