Facsimile transmission method and system

• US 4,000,371 A
• Filed: 03/12/1975
• Issued: 12/28/1976
• Est. Priority Date: 03/16/1974
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ogawa, Mutsuo
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/557,552
• Time in Patent Office: 657 Days
• Field of Search: 179/3, 179/4, 179/2 DP, 179/84 VF, 340/147 R, 178/3, 178/2 R, 178/2 B, 178/2 A, 178/2 C, 178/2 D, 178/2 E, 178/4.1 R, 178/4.1 B, 178/4.1 C, 178/26 R, 178/26 A
• US Class Current: 358/426.07
• CPC Class Codes: H04N 1/33307 prior to start of transmission, input or output of the picture signal only

Abstract

Two facsimile devices, each capable of operating in a plurality of communication modes and having at least one common communication mode are connected together by a telephone line. One of the devices sends to the other a plurality of low and high group frequency signals arranged in a code designating the possible communication modes of the device. The other device receives the signals, determines from them a common communication mode based on its own possible communication modes in accordance with a priority arrangement, and sends high and low group frequency signals to the first device indicating the selected common communication mode so that both of the facsimile devices are set to the selected common communication mode prior to the transmission of graphic information.

Claims

1. In a facsimile system including first and second facsimile devices, each device having a facsimile transceiver operable in a plurality of communication modes, at least one of the communication modes being common to the transceivers of the first and second devices, the combination with the facsimile transceiver of each of the first and second facsimile devices of:

first code storage means to store a code indicating the communication modes in which the transceiver of the respective facsimile device is operable;

code sending means to send codes representing communication modes to the other of the first and second facsimile devices;

second code storage means to store a code indicating a selected communication mode constituting one of the at least one of the communication modes common to the first and second facsimile devices, the respective transceiver being connected to the second code storage means to be set thereby to operate in the selected communication mode;

switch means to selectably connect one of the first and second code storage means to the code sending means;

priority sensing means to receive the code indicating the communication mode in which the transceiver of the other of the first and second facsimile devices is operable from the other facsimile device and feed to the second code storage means a code indicating the selected communication mode which is selected in accordance with a predetermined priority arrangement set into the priority sensing means; and

control means to control the respective transceiver;

switch means and code sending means in such a manner that;

the control means of the first facsimile device controls the switch means thereof to connect the first code storage means to the code sending means and controls the code sending means to send to the second facsimile device the code indicating the communication modes in which the first facsimile device is operable;

the priority sensing means of the second facsimile device receives from the first facsimile device the code indicating the communication modes in which the first facsimile device is operable and feeds to the second code storage means the code representing the selected communication mode to set the transceiver of the second facsimile device to the selected communication mode, the control means controlling the switch means to connect the second code storage means to the code sending means to send the code indicating the selected communication mode to the first facsimile device; and

the priority sensing means of the first facsimile device receives from the second facsimile device the code representing the selected communication mode and feeds it to the second code storage means to set the transceiver of the first facsimile device to the selected communication mode.

2. A system according to claim 1, in which each code sending means comprises encoding means and a plurality of oscillators to convert codes indicating communication modes into electromagnetic signals at a plurality of high and low group frequencies, each priority sensing means comprising a plurality of resonant circuits tuned to the high and low group frequencies and decoding means to convert the electromagnetic signals into codes.

3. A system according to claim 2, in which each code sending means further comprises scanning means to scan the codes in the first and second code storage means and sequentially convert code elements indicating individual communication modes into electromagnetic signals each consisting of a high group and a low group frequency,. frequency.

4. A system according to claim 1, in which the communication modes in which the transceivers of the first and second facsimile devices are operable include at least one of simple modulation, three-level analog compression, simple modulation combined with skip scanning, three-level analog compression combined with skip scanning and digital run length encoding, each facsimile transceiver having processing means for each of the respective communication modes in which the transceiver is operable, the processing means corresponding to the selected communication mode being selectively energized by the second code storage means.