Image Number 3 for United States Patent #6834744.
This invention has been made to provide a speaker system capable of miniaturization and presenting a good sound quality. A speaker 15 is mounted on a printed circuit board 21 arranged inside a telephone body enclosure 12. Acoustic waves of positive phase produced by vibration of a diaphragm 23 of the speaker 15 are output through front acoustic apertures 28 and a front air chamber 37 to the exterior from an enclosure acoustic aperture 13. On the other hand, the acoustic waves of opposite phase enter a rear air chamber 35 through rear acoustic apertures 29, reach an enclosure internal space 36 through an opposite-phase opening 34 provided by cutting away a part of a rear sealing member 32, and transmit to a card slot 14, then being output to the exterior. The opposite-phase opening 34 as an opening allows the acoustic waves to be output in a direction remotest from the card slot 14, so that the acoustic waves of opposite phase are output to the extension through the remotest path in the enclosure of the speaker resulting in reducing interference of the acoustic waves of positive phase and negative phase. This enables realization of a speaker system of small size but of a good sound quality.