| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light bulb or the like which improves heat radiation and reduces size and weight at the same time and which also reduces a thermal load on a lighting circuit. <P>SOLUTION: The light bulb 1 is provided with an LED module 3 with LEDs, a cylindrical case 7 having a base member 15 at one end and radiating heat during light emission of the LEDs, a loading member 5 loading the LED module 3 and transferring heat to the case 7 by blocking the other end of the case 7, a lighting circuit 11 supplied with power through the base member 15 to make the LEDs emit light, and a circuit holder 13 arranged in the case 7 and storing the lighting circuit 11. An air layer is provided between the circuit holder 13 and the case 7 as well as the loading member 5, and the lighting circuit 11 is separated from the air layer by the circuit holder 13, so that, a ratio S1/S2 of contact areas is to satisfy: 0.5≤S1/S2, when, a contact area of the loading member 5 and the case 7 is S1, and that of a substrate 17 of the LED module 3 and the loading member 5 is S2. <P>COPYRIGHT: (C)2011,JPO&INPIT |
