Mobile terminal with electromagnetic actuator
This invention deals with a portable terminal that reduces extraneous tones in a portable terminal in which is mounted an electromagnetic induction actuator that produces voice signals, a buzzer signal or a low frequency vibration. By short-circuiting the terminal fittings of the electromagnetic induction actuator or by connecting them electrically to amplifiers or to a signal generator that produces a constant voltage signal or a constant-frequency signal, the extraneous tone produced by vibration of the mechanical vibration system of the actuator is reduced.
1. A portable communication terminal for receiving an incoming communication, the terminal having a compact electromagnetic induction actuator for producing a vibration as well as an audible signal, comprising:
a magnetic vibration system having a plate magnet, a yoke and a pole piece;
a cylindrical housing enclosing an upper and a lower leaf-spring suspension which sandwich vibration system;
an audible generator disposed on one end of the cylindrical housing, the audible generator having a voice coil, a diaphragm attached to the voice coil;
a pair of input terminal disposed on the housing and connected to the voice coil and the magnetic vibration system for conveying an electrical signal having a frequency that produce a vibration in the magnetic vibration system or the audible sound generator, depending on the frequency of the electrical signal; and
an individual amplifier connected to the each input terminal and the amplifier is normally set in operating state by application of a voltage, and a signal from the input terminal is fed to one of the amplifier for adjusting the output signal of the amplifier when the portable communication terminal is awaiting an incoming call.
2. A portable communication terminal, as described in claim 1 , further comprising: a signal generation source electrically connected to the amplifier for providing a constant-voltage signal and a constant-frequency signal to the amplifier.
3. A portable communication terminal for receiving an incoming communication, the terminal having an electromagnetic induction actuator for producing a vibration as well as an audible signal, comprising:
a magnetic vibration system having a plate magnet, a yoke and a pole piece;
a cylindrical housing enclosing an upper and a lower leaf-spring suspension which sandwich the magnetic vibration system;
an audible sound generator disposed on one end of the cylindrical housing, the sound generator having a voice coil and a diaphragm attached to the voice coil;
a pair of input terminal disposed on the housing and connected to the voice coil and the magnetic vibration system for conveying an electrical signal having a frequency that produces a vibration in the magnetic vibration system or an audible sound in the round generator, depending on the frequency of the electrical signal; and
means for short-circuiting the pair of input terminal so as to short circuit the voice coil and to dampen the movement of the magnetic vibration system, when an incoming communication is not being received, so as to reduce a production of an extraneous tone in the voice coil.
4. A portable communication terminal, as recited in claim 3 , wherein the means for short-circuiting is an electronic switch.
5. A portable communication terminal, as recited in claim 3 , wherein the means for short-circuiting is an electro-mechanical switch.