Patent ID: 8240902

Claim:
A linear light source device comprising: a light guide member that includes a main body made of a transparent material in the form of a column and having a substantially uniform cross section and a predetermined length, the light guide member also including a first end and a second end provided at ends of the main body; and LED elements each arranged to face one of the first end and the second end; the main body includes a smooth mirror circumferential surface formed with a plurality of recesses or projections throughout the length thereof within a predetermined range in the circumferential direction, due to the recesses or projections, throughout the length of the main body, light emitted from the LED elements and introduced into the main body through each of the first end and the second end is emitted from a region of the circumferential surface of the main body which faces the range within which the recesses or the projections are formed, and each LED element comprises an LED chip, and each LED chip being directly mounted on a substrate made of aluminum nitride.