An LED light source mechanism configured to use one LED, Light Emitting Diode, as a light source and illuminate an illumination surface, the illumination surface being laterally long and wide in a left/right direction, wherein, the LED faces the illumination surface and has a center light emitting axis arranged at a position on a center line vertically extending from a central part in the left-right direction of the illumination surface, the LED light source mechanism has two reflection surfaces that are formed in a conical shape, the two reflection surfaces being configured to reflect light that is emitted from the LED toward an outside of the illumination surface, a center line of the conical shape is disposed on the center light emitting axis of the LED, the two reflection surfaces are: a first reflection surface having a conical shape and configured to reflect light from the LED on an outer-surface side thereof; and a second reflection surface having a truncated-conical shape, the second reflection surface including openings for light on both upper and lower surfaces thereof and configured to reflect light from the LED on an inner-surface side thereof, and an inner-surface side of the first reflection surface and the inner-surface side of the second reflection surface are disposed to be opposed to each other around the center light emitting axis of the LED, characterized in that the light of the LED enters in a light guide part at the second reflection surface, the light guide part being configured to guide light emitted from the LED to the illumination surface, wherein conical form of the second reflection surface reduces away from the LED towards the first reflection surface, which conical form is in-line with the second reflection surface and increases away from the LED; and the light is reflected on the second reflection surface at a concave inner side and on the first reflection surface at a convex outer side. the LED faces the illumination surface and has a center light emitting axis arranged at a position on a center line vertically extending from a central part in the left-right direction of the illumination surface, the LED light source mechanism has two reflection surfaces that are formed in a conical shape, the two reflection surfaces being configured to reflect light that is emitted from the LED toward an outside of the illumination surface, a center line of the conical shape is disposed on the center light emitting axis of the LED, the two reflection surfaces are: a first reflection surface having a conical shape and configured to reflect light from the LED on an outer-surface side thereof; and a second reflection surface having a truncated-conical shape, the second reflection surface including openings for light on both upper and lower surfaces thereof and configured to reflect light from the LED on an inner-surface side thereof, and an inner-surface side of the first reflection surface and the inner-surface side of the second reflection surface are disposed to be opposed to each other around the center light emitting axis of the LED, characterized in that the light of the LED enters in a light guide part at the second reflection surface, the light guide part being configured to guide light emitted from the LED to the illumination surface, wherein conical form of the second reflection surface reduces away from the LED towards the first reflection surface, which conical form is in-line with the second reflection surface and increases away from the LED; and the light is reflected on the second reflection surface at a concave inner side and on the first reflection surface at a convex outer side. a first reflection surface having a conical shape and configured to reflect light from the LED on an outer-surface side thereof; and a second reflection surface having a truncated-conical shape, the second reflection surface including openings for light on both upper and lower surfaces thereof and configured to reflect light from the LED on an inner-surface side thereof, and an inner-surface side of the first reflection surface and the inner-surface side of the second reflection surface are disposed to be opposed to each other around the center light emitting axis of the LED, characterized in that the light of the LED enters in a light guide part at the second reflection surface, the light guide part being configured to guide light emitted from the LED to the illumination surface, wherein conical form of the second reflection surface reduces away from the LED towards the first reflection surface, which conical form is in-line with the second reflection surface and increases away from the LED; and the light is reflected on the second reflection surface at a concave inner side and on the first reflection surface at a convex outer side.