Telephone group listening systems
First Claim
1. Telephone apparatus comprising:
- a handset housing a microphone transmitter;
a base set housing a loudspeaker;
a transmission bridge for transmitting an output of the microphone transmitter to a telephone line and for transmitting an input from said telephone line to the loudspeaker;
a switch between said transmission bridge and the loudspeaker for controlling input to the loudspeaker;
and transducer means within the handset operable to actuate said switch when said handset enters and exits a preset positional range relative to the base set, whereby to inhibit input to the loudspeaker when the handset is within said preset range but to pass the input to the loudspeaker when the handset is outside said preset range.
2 Assignments
0 Petitions
Accused Products
Abstract
A telephone group listening system is one in which one member of an assembled group has a telephone for communication with a remote party while the other members may only listen to the communication through the agency of a loudspeaker. The system is subject to the Larsen effect on call answering or clear down if the telephone handset is normally sited close to the loudspeaker. This effect is overcome by including a proximity switch in the loudspeaker circuit, the switch being triggered by a change in the level of coupling of a capacitively or inductively coupled circuit, the coupling being dependent on the closeness of the speaker'"'"'s body to the switch or on the separation of the handset and the loudspeaker.
24 Citations
9 Claims
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1. Telephone apparatus comprising:
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a handset housing a microphone transmitter; a base set housing a loudspeaker; a transmission bridge for transmitting an output of the microphone transmitter to a telephone line and for transmitting an input from said telephone line to the loudspeaker; a switch between said transmission bridge and the loudspeaker for controlling input to the loudspeaker; and transducer means within the handset operable to actuate said switch when said handset enters and exits a preset positional range relative to the base set, whereby to inhibit input to the loudspeaker when the handset is within said preset range but to pass the input to the loudspeaker when the handset is outside said preset range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification