摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bulb-shaped lamp capable of achieving improvement in heat radiation, down-sizing and weight reduction simultaneously, and capable of decreasing a heat load to a lighting circuit. <P>SOLUTION: The bulb-shaped lamp 1 includes: an LED module 3 having LEDs; a cylindrical case 7 having a base member 15 at one end and radiating heat when the LEDs emit light; a mounting member 5 mounting the LED module 3, closing the other end of the case 7 and transmitting the heat to the case 7; and a lighting circuit 11 to make the LEDs emit light after receiving power through the base member 15. The LED module 3 is mounted on a small diameter part side of the mounting member 5 and moreover an outer peripheral face of a large diameter part contacts with an inner peripheral face of the case 7. When a contact area between the mounting member 5 and the case 7 is S1 and a contact area between a substrate 17 of the LED module 3 and the mounting member 5 is S2, a ratio S1/S2 of the contact areas satisfies 0.5≤S1/S2. <P>COPYRIGHT: (C)2011,JPO&INPIT |