| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a low-cost LED lighting device of a reduced size which attains bright illumination without concern for the breakage of LED elements. <P>SOLUTION: The LED lighting device having a light emitting portion consisting of a single or a very small number of high-intensity white LEDs 2, comprises PWM control means 17 for controlling a driving current of the LEDs 2, temperature detecting means 19 for detecting junction temperature of the LEDs 2 based on Vf of the LEDs 2 detected by Vf detecting means 18, and control means 20 for controlling the PWM control means 17 to allow a low current to flow through the LEDs 2 at the time of detecting temperature and for adapting the temperature detected then by the temperature detecting means 19. The device is arranged such that the junction temperature is monitored by the control means 20. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
