Communication device
AssigneeBrother Kogyo Kabushiki Kaisha
InventorSusumu Chida
Life of this patent
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Abstract
When a facsimile device detects an audio signal via a CNG signal detection unit while detecting an OFF signal in a CNG signal during a telephone conversation, the facsimile device does not detect the audio signal as an OFF signal if the level of the detected audio signal is greater than a threshold and the frequency of the audio signal is within a predetermined audio frequency range. Accordingly, the facsimile device can reliably prevent a false detection of a noise that has a similar signal component to a CNG signal as a CNG signal. It is possible to prevent the facsimile machine from being automatically shifted to a facsimile receiving made by the false detection of the noise.
Claims32
A communication device, comprising:
- a facsimile receiving portion that detects a facsimile activation signal that is transmitted from a remote device via an external communication line while a telephone conversation is being executed with the remote device, and that switches from telephone function into facsimile function to execute facsimile receiving operation;
- and
- an error preventing portion that prevents the facsimile receiving portion from erroneously executing the facsimile receiving operation based on noise.
Dependencies are inferred from the claim text.