Abstract: In an LED light bulb, an LED module and a lens are disposed on a fixing stage provided to a housing. The lens has a concave portion at its top end. The concave portion forms a reflecting surface which reflects part of outgoing light from the LED module to (i) first directions perpendicular to a front emission direction of the outgoing light or (ii) second directions leaning to a cap beyond the first directions. Due to diffusion effect of an optical cover, part of the light reflected by the lens is emitted backward (toward the cap). This realizes an LED light bulb that distributes light over an entire circumference and has high output as well as high light output ratio.

Abstract: In an LED light bulb, an LED module and a lens are disposed on a fixing stage provided to a housing. The lens has a concave portion at its top end. The concave portion forms a reflecting surface which reflects part of outgoing light from the LED module to (i) first directions perpendicular to a front emission direction of the outgoing light or (ii) second directions leaning to a cap beyond the first directions. Due to diffusion effect of an optical cover, part of the light reflected by the lens is emitted backward (toward the cap). This realizes an LED light bulb that distributes light over an entire circumference and has high output as well as high light output ratio.