Facsimile arrangement having automatic answering telephone set and facsimile set and switching process therefor

A telephone system having an automatic answering unit and a facsimile unit, comprising:

• incoming signal detection means for detecting an incoming signal,
• signal determination means for determining whether the incoming signal is a facsimile signal, the signal determination means comprising speech signal determination means for determining whether the incoming signal includes a speech signal and facsimile signal determination means for determining whether the incoming signal includes a CNG signal, whereby the incoming signal is determined to be a facsimile signal when the signal determination means determines that the incoming signal does not include a speech signal and the facsimile signal determination means determines that the incoming signal includes a CNG signal, and
• reception mode switching means for connecting a telephone line to the automatic answering unit upon detection of the incoming signal regardless of whether the incoming signal is a speech signal or a facsimile signal and for disconnecting the telephone line from the automatic answering unit and connecting the telephone line to the facsimile unit if the incoming signal is a facsimile signal;
• wherein the reception mode switching means comprises:
• 1,100 Hz signal detection means for detecting a 1,100 Hz signal,
• means for disconnecting the telephone line from the automatinc answering unit and for connecting the telephone line to the facsimile unit when the 1,100 Hz signal detection means detects a signal of 1,100 Hz,
• a timer for determining whether a predetermined period of time has elapsed after the incoming signal is detected,
• means for starting the timer upon the detection of the incoming signal,
• means for maintaining the connection between the telephone line and the automatic answering unit until the timer determines that the predetermined period of time has elapsed,
• a detector for detecting whether the automatic answering unit is in an on-hook state or an off-hook state, and
• means for disconnecting the telephone line from the automatic answering unit and for connecting the telephone line to the facsimile unit when the automatic answering unit is in the on-hook state before the elapse of the predetermined time.