Abstract: A speaker includes: a speaker unit; a baffle fitted with the speaker unit; a cabinet fixed to the baffle, the cabinet covering a back of the speaker unit; a plurality of mounting bosses projected from at least one of the baffle and the cabinet; and a packing having elongated mounting holes, the packing located at an abutting part between the baffle and the cabinet, the packing sealing the abutting part. The abutting part includes a plurality of similar sealing areas, which are substantially common in size and shape as a whole except that at least one projecting position of the mounting boss is slightly shifted. The elongated mounting holes of the packing is used for the similar sealing areas. The elongated mounting holes of the packing correspond to the at least one projecting position of the mounting boss and compensate a position shift between the similar sealing areas.

Abstract: A driving apparatus according to the invention turns on a capacitive light emitting device having a first electrode and a second electrode in accordance with a light-on instruction. The apparatus has: a voltage accumulating unit, for example, a capacitor for holding a voltage energy corresponding to the contents of the light-on instruction; a circuit for applying the voltage energy held in the voltage accumulating unit to a portion across electrodes (A and B) in one direction in response to a first control signal and for applying the voltage energy held in the voltage accumulating unit to the portion across the electrodes in the other direction in response to a second control signal; and a circuit for alternately generating the first and second control signals. The invention can cope with a deterioration due to an aging change or the like, prevent a reduction of a light emission intensity due to the deterioration or the like, and contribute to a simplification of the construction and a decrease in costs.