PURPOSE: To suppress loss of light, to miniaturize an apparatus and to make it possible to rapidly and visibly recognize the presence of a dispaly, such as fire hydrant signals, etc., by using light leakage preventive means at the time of transmitting the light of light emitting diodes to many adjacent optical fibers.

CONSTITUTION: This device consists of an enclosure 4 which consists of a pair of semicylindrical bodies provided with first and second supporting pieces 4-1 disposed at both ends, a first panel which is fixed to the first supporting piece 4-1 of this enclosure 4, is provided with plural through-holes 5 over the circumferential edge and is provided with a signal display part, a second panel which is fixed to the second supporting piece of the enclosure 4, a housing section 9 which is formed of the enclosure 4 and the first and second panels, the optical fibers 7 which are housed in this housing section 9 and are respectively inserted and fixed at their one-side ends into the through-holes 5 provided in the first or the second panel and the light emitting diodes 8 which are housed in the housing section 9, disposed adjacently to the other end edges of the bundles formed by bundling the other-diode ends of plural pieces of the optical fibers 7 to each other and cutting these ends and have light leakage preventive means.