Patent ID: 8339051

Claim:
A manufacturing method of an electronic flash unit, the unit comprising: a housing having a first hole, a second hole, and an opening; a transformer to vary voltages of a power supply; an accumulator composed of a main capacitor to charge an electric energy supplied from the transformer; a lamp unit provided with a flashlamp, set inside of a reflector, that flashes by discharging of energy storages in the main capacitor by a voltage applied on a trigger terminal; and a trigger circuit to generate voltages to apply on the trigger terminal, the method comprising steps of: filling the housing, as a mold, with an insulation material in a condition such that at least the lamp unit is disposed in the housing and fitted to the opening to seal the opening; and coating at least the lamp unit with the insulation material by hardening the insulation material, wherein: the insulation material is supplied into the mold from the first hole as an input hole, and air in the mold is exhausted from the mold through the second hole as a vent hole while the insulation material is filled into the mold so as not to leave a space in the mold.