Telephone with slim casing and loudspeaker - has loudspeaker compartment forming two-cavity resonance system in telephone housing, with tuned frequency characteristics for ringing tone generation and hands-free operation

摘要

The telephone apparatus includes a loudspeaker (3) for generating a ringing tone and for hands-free operation. The loudspeaker is fixed in a compartment (4) in the lower part (2) of the telephone housing by a collar (5) which overlaps the edge of the compartment. A pressure ring (6) in the upper part (1) of the housing clamps the loudspeaker in place. The loudspeaker compartment has an acoustic opening (7) of defined size and direction, for coupling the volumes of the loudspeaker compartment and the telephone housing. This two-cavity resonance system is tuned such that the frequency response is within a set range. The loudspeaker compartment is pref. formed in the base of the lower part of the housing. ADVANTAGE - Achieves desirable frequency characteristics, even with thin construction of telephone housing.