A translucent member is arranged so as to cause light originating from an LED
light
source oriented toward the front of a lamp to enter the translucent member. Outgoing
LED light that has entered the translucent member is reflected rearward by a front
surface, and then the light is reflected forward by a rear surface, to thereby
exit forward of the lamp from the translucent member. At that time, an area on
the front surface located in the vicinity of an optical axis Ax is formed as a
normal reflection section subjected to reflection surface treatment. The other
area of the front surface is formed as an internal reflection section which causes
the outgoing LED light to undergo internal reflection. A plurality of reflection
elements are formed on the rear surface of the translucent member so as to cause
the outgoing LED light reflected from the front surface to enter the internal reflection
section at an incidence angle which is smaller than or equal to a critical angle.