JPH04336861A - Cordless facsimile equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless facsimile machine.

0002

[Prior Art] Conventionally, cordless facsimile machines are
It uses a cordless phone system and replaces the cordless phone with a facsimile machine.

0003

[Problem to be Solved by the Invention] However, in the above conventional example, the communication channel between the base unit and the slave unit is based on radio waves, so the S/N (S/N ratio) of the communication channel is reduced by using a modular code. It is not as stable as it would be if there were.

[0004] Therefore, if training fails in such a system, there is a possibility that training will fail again even if the speed is lowered by one level, resulting in increased communication costs and radio waves due to the increased time required for the procedure. The disadvantage is that it consumes more power.

[0005]

[Means for Solving the Problems] According to the present invention, means for measuring the S/N of a received signal is provided on the handset side of a facsimile machine, and the own device is set to the highest speed that can be received at that S/N. By changing the content of the DIS and re-declaring it, increases in communication costs and power consumption are suppressed.

[0006]

[Example] Figure 1 shows a facsimile machine (
FIG. 2 is a block diagram of a slave device. In FIG. 1, numeral 5 is an antenna, 9 is a modulation/demodulation section for a cordless phone, and facsimile communication is carried out from a modem 10 through these. Reference numeral 11 denotes an S/N (S/N ratio) evaluation circuit that evaluates the S/N of the received signal. 3 is a printing section, 12 is an operation section for operating the facsimile machine, 13 is a reading section for reading a document during transmission, 14 is a ROM (read only memory) that stores control programs and various table data, and 15 is a work area. , RAM (Random Access Memory) used as image data memory, etc. Finally, numeral 16 is a control section composed of a microprocessor and the like as the main control section of the facsimile machine. In the figure, thick lines represent analog signals, and lines connected to the control section are used for control or digital data transfer.

[0007] The ROM 14 stores a table in which the maximum receivable speed is registered for each S/N ratio of the received radio signal.

FIG. 2 is a perspective view of a facsimile machine using a cordless phone system. In FIG. 2, reference numeral 1 indicates a facsimile machine which is a handset, and 2 indicates a numeric keypad on the operation panel, which is used when making a call from the facsimile machine. Reference numeral 3 represents a printing section for a received document, and reference numeral 4 represents a handset for making calls. 6 is a base unit of the cordless phone system, and 8 is a modular cord that connects the base unit 6 to a telephone line. Further, 5 and 7 are antennas for performing wireless communication between the base unit and the slave unit, which both have.

Next, the actual operation will be explained. When receiving a facsimile, a communication channel of a certain frequency is set between the base unit 6 and the handset 1, and reception is performed according to the protocol as shown in FIG. For purposes of explanation, the maximum speed of the transmitter is 9600 bps (bits per second), and the receiving speeds of the receiver are 9600, 7200, 9800, and 2400 bps.

In FIG. 3, the training at 9600 bps is successful, so the speed of the image signal is 9600 bps.

Next, the operation when the first training fails will be explained. In conventional facsimiles, when training fails, the receiving side sends out an FTT, and the transmitting side, upon receiving it, falls back to the speed of 7200 bps and performs training again.

In contrast, the control section 16 of this embodiment
If it is determined that the first training was unsuccessful, S/
S/N of the training signal received from the N evaluation circuit 16
Pull out the data. Then, the control unit 16 determines the highest speed that can be received at that S/N by referring to the table data in the ROM, changes the speed declaration of DIS, and
Re-declaring IS.

[0013] Here, based on the evaluated S/N data, the speed has been reduced from 9600bps to 4800bps,
This eliminates the waste of 7200 bps training.

[0014]

[Effects of the Invention] As explained above, instead of simply falling back when training fails, by changing the content of the own device's DIS and re-declaring it based on the S/N of the received signal, the image reception status can be changed immediately. This has the effect of suppressing increases in communication costs and power consumption.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a facsimile device (slave device) according to an embodiment.

FIG. 2 is a facsimile machine using the cordless phone system of the embodiment.

FIG. 3 is a protocol diagram for a successful first training.

FIG. 4 is a protocol diagram when training fails and DIS is re-declared.

[Explanation of symbols]

1. Handset (Facsimile) 9 Modulation/demodulation section for cordless phone 10 Modem 11 S/N evaluation circuit 14 ROM 16 Control section

Claims (1)

[Claims] Claim 1: In a cordless facsimile device, when training fails when receiving a facsimile,
A cordless facsimile device is characterized in that it evaluates the SS/N ratio of the training signal, changes the content of its own DIS in accordance with the SS/N ratio, and re-declares it.