US Patent 7021799 Light source unit

Light-emitting element arrays having aligned LEDs are fixed to a stand integrally formed with a heat sink. An attachment surface of the stand is formed with V-shaped grooves working as reflection planes for improving irradiation efficiency. The arrays are separated from printed-circuit boards to be bonded therewith by wires. The array is placed at the bottom of the groove. The printed-circuit board is placed on a step formed at a wall of the groove. Since the array is separated from the resinous printed-circuit board having inferior heat conductance, high efficiency of heat radiation is obtained. Further, since the array is disposed close to the wall, unevenness of intensity distribution of the LEDs is prevented from being enlarged.