CN1114481A - Communication terminal device - Google Patents

Abstract

A communication terminal device, in which a CPU 7 detects the rise of an intermittent signal on a telephone line 5 based on input data from a signal level detection circuit 11 which a recorder 3 is being operated, and measures the period of the rise of the intermittent signal. The CPU 7 compares past three periods measured continuously from the rise time of the signal at every rise of the intermittent signal, respectively, and judges that the period of the rise of the intermittent signal is kept constant when the time difference among the periods is within 100msec. When it is judged that the invariability of the period of the rise is kept for continuous three times, the CPU 7 assumes the intermittent signal on the telephone line 5 as the busy tone, and judges that the line disconnection is performed on the transmission side.

Description

Communication terminal

The present invention relates to picture unit and having and be used for communication terminals such as automatic answering telephone to the recording device of recording from the acoustic information of originator.

This automatic answering telephone is exhaled words signal from telephone exchange by what telephone line sent according to what receive, connects telephone circuit and carries out signal and receive.For this reason, after originator is sent answer signal, the audio information recording from originator is got off by recording device.In addition, if under the state that this recording device is being worked, originator has hung up receiver and has cut off circuit, and telephone exchange will send busy-back signal.And, thereby when having detected this busy tone and judge that circuit has been cut off, recording device just quits work.

Above-mentioned busy-back signal in the telephone exchange is the pulsed sound tone signal of sending with certain cycle with given frequency.As shown in Figure 2, the time that sends busy-back signal is called the logical time, the time that stops from transmission to sending is once more called the break time, so logical time and the one-period break time and that just constituted busy-back signal.For example in Japan, the frequency of regulation busy-back signal is 400Hz, and the cycle is 1S (logical time and break time are 0.5s).

In addition, in the memory of device in the past,, preestablish and stored frequency, the data of conditions such as logical time and break time in order to judge busy-back signal.So, during the signal that on being received in telephone line, transmits,, just judge that this signal is a busy-back signal if the frequency of this signal conformed to above-mentioned condition data with the cycle (logical time and break time), judge promptly that also circuit cuts off.

Yet in different countries, the frequency of busy-back signal is different with the cycle (logical time and break time).Therefore, can use at all regions in order to make device, just be necessary to change the condition data that memory is wherein stored respectively corresponding to the set area of device, this is the work that bothers very much.

The present invention is exactly in order to eliminate above-mentioned problem.The purpose of this invention is to provide a kind of communication terminal, it does not need to store in advance the data that are used for judging busy-back signal that the area is set corresponding to device, no matter but what area device is arranged on, can both detect busy-back signal reliably, correctly determination circuit situation about having cut off.

In order to achieve the above object, be provided with in the present invention with lower device: the measuring device in cycle that is used for measuring the zero hour of the signal that transmits on the telephone line; Be used for whenever first judgment means that occurs judging when signal begins that the above-mentioned cycle is whether identical; And be used for that a continuous a certain given number of times is judged identical situation of cycle and be judged to be second judgment means that signal is periodic pulsed sound tone signal.

In addition, be that above-mentioned judgment means will judge whether the cycle is certain in the situation of 250ms in 2.5 scopes for the signal cycle zero hour that measures by measuring device.

Have again, above-mentioned judgment means compares mutually to the cycle more than three of continuous measurement in a plurality of signal cycle zero hour that is measured by measuring device at least, if the difference in these cycles is in given time value, then the cycle of decision signal zero hour is certain.

So,, can in received signal, make recording device work, and the acoustic information from originator is recorded according to the present invention.And, under the state of recording device work, measure the cycle of the zero hour of the signal that on telephone line, transmits by measuring device.In addition, first judgment means just judges when discontinuous signal begins whether the cycle of the zero hour is certain.At this moment, be certain situation for continuous given number of times determination cycles, busy-back signal has appearred in second judgment means just judgement on telephone line, and circuit is cut off.

In a word, because the busy-back signal that is sent by telephone exchange is that the certain cycle zero hour is arranged, if think the zero hour of signal there is certain cycle so continuous several times is judged, just can judge reliably from what post a letter the aspect is not acoustic information, but busy-back signal.In addition, owing to only measured the initial cycle in the moment of discontinuous signal, so no matter can detect the busy-back signal in what area reliably, judge that correctly circuit is cut off, and all it doesn't matter with the frequency of busy-back signal, logical time or break time.Have again, no longer include the necessary data that are used for judging busy-back signal that the area is set corresponding to device of storing in advance.

In addition, for cycle of the signal zero hour that measures by measuring device situation in 250ms～2.5 scopes not, not busy-back signal because learnt this signal, so whether the cycle of no longer carrying out is certain judgement.Therefore, even the cycle of the zero hour is certain signal, also can think the signal outside the busy-back signal, for example be the voice signal from the aspect of posting a letter, thereby can judge more correctly whether circuit is cut off.

Have again, in the cycle zero hour of the discontinuous signal that measures by measuring device, will compare mutually the cycle more than three of continuous measurement at least.And, when time difference in these cycles is within given time range, just judges and think that cycle of the zero hour of discontinuous signal is certain.

Below, accompanying drawings communication terminal of the present invention is used to have a specific embodiment of the facsimile machine of absence recording function.

Fig. 1 is the circuit diagram that a specific embodiment of the communication terminal of the present invention that has the absence recording function in the picture unit is shown.

Fig. 2 is the sequential chart that the signal level of the telephone line that is detected by the signal level detection circuit is shown.

Fig. 3 is the flow chart of its this body running when the picture unit received signal is shown.

Fig. 4 is the flow chart of recording device work when the picture unit received signal is shown.

Fig. 5 is that the flow chart of " circuit cuts off and judges subprogram " of circuit dissengaged positions is judged in explanation by performed being used for of the CPU of picture unit body.

The explanation of symbol:

3 ... recording device, 4 ... additional telephone machine, 5 ... telephone line, 7 ... constitute the CPU, 8 of measuring device, judgment means and decision maker ... constitute the ROM, 9 of measuring device, judgment means and decision maker ... constitute the RAM, 11 of measuring device, judgment means and decision maker ... constitute the signal level detection circuit, 27 of measuring device ... DSP, 32 ... stay-at-home key, T1, T2, T3 ... cycle.

As shown in Figure 1, this facsimile machine 1 contains facsimile machine body 2, has the additional telephone machine 4 and the NCU (network control unit) 6 of recording device 3.Facsimile machine body 2 carries out bipartite view data transmission and receives the action of also promptly faxing.Recording device is recorded to the acoustic information from originator.NCU6 control is connected with telephone line 5.In addition, additional telephone machine 4 is arranged on and becomes one in the facsimile machine 1, has again, also is provided with to be connected extension 37 on the facsimile machine 1 by scheming to go up unillustrated cable.

Here above-mentioned facsimile machine body 2 is described.On CPU (CPU) 7, connected to store and be used for controlling facsimile machine the body 2 all ROM (read-only memory) 8 and the temporary transient RAM (random access memory) 9 of storing various information of the program of the action of action and NCU6.10 pairs of information that send and receive of modulator-demodulator are carried out modulation and demodulation, to produce and to survey button acoustical signal (DTMF), digital command signal (DCS) and the digital identification signal (DIS) etc. corresponding to the communication counterpart telephone number.In addition, also be provided with signal level detection circuit 11 in the modulator-demodulator 10,11 pairs of signal levels that transmit on telephone line 5 of this signal level detection circuit are sampled, and export to CPU7 with the form of numerical data.Then, CPU7 is according to the level of signal on the data identification telephone line 5 of input.

Have again, on above-mentioned CPU7, also connected and be used for reading reading part 12, being used for according to the view data that receives at the recording section 13 that prints on the record-paper and the various operation keyss such as start key (not shown on the figure) that are used for starting the fax action of original copy epigraph.

The following describes above-mentioned additional telephone machine 4.In additional telephone machine 4, be provided with the dialing CPU21 of the telephone set 4 whole actions that are used for controlling except recording device 3.In this dialing CPU21, connected and be used for dial key 22 of importing telephone number etc. etc.In addition, also connected telephone receiver 23 on the additional telephone machine 4.

Be provided with in above-mentioned recording device 3 and be used for controlling all CPU24 of action of this device 3, the action relevant with the absence recording of additional telephone machine 4 controlled by this CPU24.In addition, CPU24 is connected on the above-mentioned dialing CPU21 by optical coupler 25; Be connected on the CPU7 of above-mentioned facsimile machine body 2 by the bus (universal serial bus) 26 that is used for carrying out serial communication.And, between the CPU7 of the dialing CPU21 of the CPU24 of recording device 3, additional telephone machine 4 and facsimile machine body 2, carry out serial communication.

DSP (digital signal processor) the 27th is used for voice signal is carried out digital processing, and it is connected with above-mentioned CPU24 by address bus 28 and data/address bus 29.This DSP27 contains with the RAM30 of coding form stored sound data and is used for coding and decoding circuit 31 to the voice data Code And Decode.In addition, on the CPU24 of this recording device 3, also be connected with the stay-at-home key 32 and the regeneration key various operation keyss such as (not shown on the figure) that are used for regenerating and are stored in the voice data among the RAM30 that is used for setting and removing stay-at-home/fax pattern (will there be explanation the back).

The following describes above-mentioned NCU6.Wherein be provided with the CML relay 36 that is used for selectively telephone line 5 being connected to modulator-demodulator 10 1 sides of above-mentioned facsimile machine body 2 or is connected to above-mentioned telephone set 4 and 37 1 sides.Under the control of the CPU7 of facsimile machine body 2, when CML relay 36 switched to contact a one side, telephone line 5 just was connected to telephone set 4 and 37 1 sides.On the other hand, when CML relay 36 switched to contact b one side, telephone line 5 just was connected to modulator-demodulator 10 1 sides by transformer 38.Also have, the design of this CML relay 36 makes that it is switched to contact a one side when device is in the communication holding state.

Received signal detection circuit 39 contains optical coupler, and wherein LED (light-emitting diode) 39a is connected on the contact a of above-mentioned CML relay 36, and phototriode 39b is connected on the CPU7 of facsimile machine body 2.And CPU7 is by monitoring the on off operating mode of phototriode 39b, survey that whether appearing at the 16Hz from telephone exchange that transmits on the telephone line 5 exhales the words signal.First and second receivers detection circuit 40 and 41 of disembarking is connected on above-mentioned additional telephone machine 4 and the extension 37.Have again, two receivers are disembarked, and detecting telephone machines 4 and 37 receiver escape status (are the state that receiver is picked up to detection circuit 40,41 respectively, also comprise the state that recording device 3 is being worked for additional telephone machine 4), and result of detection is exported to the CPU7 of facsimile machine body 2.Also have, also export to the dialing CPU21 of additional telephone machine 4 by disembark result that detection circuit 40 detected of additional telephone machine 4 one sides' first receiver.

Dc voltage generating circuit 42 is used for providing given electric current for the receiver escape status of surveying two telephone sets 4 and 37 to telephone set 4 and 37, and its input voltage is+24V.That is to say that when the receiver escape status appearred in telephone set 4 or 37, the variation of the electric current of supplying with to this telephone set was just detected by the above-mentioned receiver detection circuit 40 or 41 of disembarking.And this electric current that detects according to the detection circuit 40,41 of being disembarked by receiver changes, and the dialing CPU21 of the CPU7 of facsimile machine body 2 and additional telephone machine 4 just identifies the receiver escape status.

In addition, this dc voltage generating circuit 42 can be connected on telephone set 4 and 37 by switching through TEL relay 43.And under the control of the CPU7 of facsimile machine body 2, when TEL relay 43 switched to contact a one side, telephone set 4,37 just was connected on the telephone line 5.On the other hand, when TEL relay 43 switched to contact b one side, telephone set 4,37 just was connected on the dc voltage generating circuit 42.Also have, the design of this TEL relay 43 makes that it is switched to contact a one side when device is in the communication holding state.Transformer 44 is connected with telephone set 4,37, and its output side is connected with above-mentioned modulator-demodulator 10.

As mentioned above, in this facsimile machine 1,, can realize the setting and the releasing of stay-at-home/fax pattern by the operation of stay-at-home key 32.That is to say that stay-at-home when setting/during the fax pattern, if exhale the words signal from what telephone exchange was sent 16Hz, then the CPU7 of facsimile machine body 2 will receive detection circuit 39 by signal and detect this and exhale the words signal.And, exhale words during signal when what CPU7 detected given number of times (being 2 times in the present embodiment), just send signal reception command signal to the CPU24 of recording device 3, this CPU24 is learnt want received signal.So the CPU24 of recording device 3 makes the DSP27 action, read the audio inquiry information data of recording in advance that is stored among the RAM30.And to the decoding of this audio inquiry information data, DSP27 sends the signal of decoding to telephone line 5 by NCU6 in the process coding and decoding circuit 31.

Thereafter, when reading of audio inquiry information finished, the CPU24 of recording device 3 just started the recording action of DSP27 on the one hand, sends the recording commencing signal to the CPU7 of facsimile machine body 2 on the one hand, makes this CPU7 learn that recording begins.In addition, when originator sent acoustic information, DSP27 encoded to these acoustic information data in coding and decoding circuit 31, and is stored among the RAM30.

In addition, after the recording action beginning, facsimile machine body 2 is just surveyed the CNG signal from originator, and when the preset time (being 8s in the present embodiment) that detected the tone-off state continuance, it just is transformed into contact b side to CML relay 36 from contact a side.That is facsimile machine body 2 judges that originators are facsimile machine, just telephone line 5 is transformed into modulator-demodulator 10 1 sides from telephone set 4,37 1 sides, and beginning is according to the operation of faxing of predetermined fax step.

In addition, as shown in Figure 2, the CPU7 of facsimile machine body 2 according to the data by 11 inputs of signal level detection circuit, is identified in the signal level that transmits on the telephone line 5 after the recording commencing signal of having imported from the CPU24 of recording device 3.And, when this signal level be higher than predetermined level (in the present embodiment for-33dBm) time, CPU7 just judges that this signal has begun to produce, promptly signal begins.Then, the time between CPU7 measures and to begin to begin to next signal from the signal of determining like this, promptly measure the discontinuous signal cycle of the zero hour.

In addition, the CPU7 of facsimile machine body 2 judges whether the above-mentioned discontinuous signal cycle zero hour that measures is certain at each discontinuous signal the zero hour.In detail, in each discontinuous signal zero hour, CPU7 mutually relatively should the zero hour continuous period T 1, T2, the T3 that measures for three times in front.That is to say, mutually period T 1, the preceding period T that once measures 2 that has more just measured and 3 these three cycles of period T that last time measured.And, for the time difference of these period T 1, T2, T3 at the fixed time (being 100ms in the present embodiment) judge then that with interior situation the discontinuous signal cycle zero hour is certain.And, CPU7 only 1 of the period T that has just measured under the situation within the 250ms-2.5 scope, just carry out whether certain judgement of cycle.

In addition, in the present embodiment, judgment means is that CPU7, ROM8 and the RAM9 by facsimile machine body 2 constituted.That is, judge that in the CPU7 of facsimile machine body 2 continuous several times (being 3 times in the present embodiment) the above-mentioned discontinuous signal cycle zero hour is under certain situation, think that just this discontinuous signal is the busy-back signal that sends from telephone exchange, judge that circuit disconnects.So CPU7 sends the command signal of recording about finishing to the CPU24 of recording device 3, and when the CPU24 of recording device 3 has been transfused to the End of Tape command signal, the recording action of DSP27 is stopped.

Below, have the effect of the facsimile machine that has absence recording machine function of said structure by the flowchart text of the sequential chart of Fig. 2 and Fig. 3 to Fig. 5.Also have, the explanation of program shown in Figure 3 and program shown in Figure 4 is interknited concurrently carry out.

When the facsimile machine that has absence recording machine function during in received signal, the control of CPU7 is to carry out according to the action shown in Fig. 3 flow chart in facsimile machine body 2.Also have, be set at facsimile machine stay-at-home/during the fax pattern, design to such an extent that make CML relay 36 and TEL relay 43 connect side to contact a.

As shown in Figure 3, when telephone exchange is exhaled the words signal by what telephone line 5 was sent 16Hz here, and receive detection circuit 39 by signal and detect 2 times this is when exhaling the words signal, CPU7 just sends signal by universal serial bus 26 to the CPU24 of recording device 3 and receives command signal, it is learnt want received signal (step S101-S102).Thereafter, send at recording device 3 and to answer after acoustic information finishes, CPU7 just waits for the recording commencing signal (step S103) of input from the expression recording action beginning of the CPU24 of recording device 3.

When the recording commencing signal imported from the CPU24 of recording device 3, CPU7 just carries out following decision operation.That is to say, recording device 3 record the action during, whether detect the CNG signal, whether detect the tone-off state in continuous 8 seconds, the state of setting in " circuit cuts off and judges subprogram " in aftermentioned Fig. 5 of judging flag and the receiver that whether detects recording device 3 are hung up the judgement (step S104-S107) of state etc.

Below, above-mentioned every decision operation is described successively.At first in step S104, judge whether to detect the CNG signal.Wherein, when detecting the CNG signal, CPU7 just sends End of Tape command signal (step S108) to the CPU24 of recording device 3.And, when sending this End of Tape command signal, CML relay 36 is transformed into the b side, make telephone line be connected to modulator-demodulator 10 1 sides, according to predetermined fax step, begin to receive facsimile signal reception operation (step S109) from the view data of originator.

Also promptly, when detecting the CNG signal from originator, just judge that originator is a facsimile machine.And carrying out sending CED signal and DIS signal, and after predetermined facsimile signals such as originator reception DCS signal exchanged, recording section 13 just moved, and prints the view data of sending here from originator on record-paper to originator.When fax received release, circuit was cut off, and returns wait state under stay-at-home/fax pattern.

In addition, if in above-mentioned steps S104, do not detect with CNG signal, then judge whether to detect the tone-off state (step S105) in continuous 8 seconds.Wherein, when detecting the tone-off state, just transfer to above-mentioned steps S108, as described above, send the End of Tape command signal, begin fax and receive operation to the CPU24 of recording device 3.

That is, for the tone-off state that does not detect continuous 8 seconds such as any voice signal etc., just be judged to be the be through with transmission of acoustic information of originator, perhaps there is not acoustic information.And, in above-mentioned steps S104, not detecting this fact of CNG signal, then be judged to be this owing to originator is to carry out facsimile with manually posting a letter, thus do not detect the CNG signal, so transfer to the fax operation thereafter.

In addition, for the situation that in above-mentioned steps 105, does not detect the tone-off state, whether then judge in " circuit cut off judge subprogram " of aftermentioned Fig. 5 and " 1 " (step S106) judging that flag is set at.,, judge that then originator hung up receiver here, cut off circuit, thereby sent End of Tape command signal (step S110) to the CPU24 of recording device 3 for judging that flag is set at the situation of " 1 ".Under stay-at-home/fax pattern return communication wait state thereafter.

In addition, for judging that in step S106 flag is not set at the situation of " 1 ", judge that then the receiver of disembarking first receiver whether detection circuit 40 having detected recording device 3 hangs up state (step S107)., hang up the situation of state here, then turn back to above-mentioned steps S104 for the receiver that does not detect recording device 3.In addition, hang up the situation of state for the receiver that detects recording device 3, then circuit is cut off, turns back to wait state.That is in the present embodiment, having set once the maximum record length of recording action is 5 minutes, and when the recording action had surpassed 5 minutes, the recording action of recording device 3 just stopped, and receiver occurs and hangs up state.And, disembark receiver that detection circuit 40 detects this recording device 3 when hanging up state when first receiver, the judged result of step S107 is a "Yes", so cut off circuit, returns wait state.

Also have, though on this flow chart, do not illustrate, if but from above-mentioned steps S102, sending signal reception instruction to inform that its received signal begins to the CPU24 of recording device 3, this section till recording action in recording device 3 stops is in period, pick up the receiver 23 of additional telephone machine 4 or make extension 37 be in the receiver escape status, the action of recording device 3 is stopped, becoming the state that to converse.

On the other hand, corresponding with the operation of above-mentioned facsimile machine body 2, the control operation of the CPU24 in the recording device 3 is that the flow chart according to Fig. 4 carries out.That is when having imported signal from the CPU7 of facsimile machine body 2 and receive command signal (step S201), DSP27 just begins action, reads the audio inquiry information data in the RAM30.And, after the decoding of this audio inquiry information data through coding/decoding circuit 31, be sent to originator (step S202) by NCU6 and telephone line 5.

When audio inquiry information send end (step S203), the recording action beginning of DSP27 in (step S204), to the CPU7 of facsimile machine body 2 send recording commencing signal (step S205) thereafter.And when originator sent acoustic information, these acoustic information data were encoded in coding/decoding circuit 31, and store among the RAM30.

In addition, from above-mentioned recording action beginning before reaching maximum record length 5 minutes, if imported the End of Tape command signal (step S206-S207) from the CPU7 of facsimile machine body 2, DSP27 just stops recording action (step S208), returns wait state thereafter.In addition, if do not import the End of Tape command signal, but by 5 minutes, then transfer to above-mentioned steps S208, the recording action of DSP27 stops, and returns wait state thereafter.

Also have, though in this flow chart, do not illustrate, if but begin in the CPU7 of the facsimile machine body 2 from above-mentioned steps S201 input received signal command signal, recording action up to DSP27 stops this section in period, the receiver 23 of additional telephone machine is picked up or extension is become the receiver escape status, then recording device 3 stops action, becomes the state that can converse.

The following describes processing operation about the judgement flag state of judging among the step S106 that is set in above-mentioned flow chart shown in Figure 3.

Flow chart shown in Figure 5 is to be used for illustrating that CPU7 by facsimile machine body 2 judges " circuit cuts off and judges subprogram " figure of circuit dissengaged positions.In the step S103 of flow chart shown in Figure 3, after the CPU24 of recording device 3 input recording commencing signal, be somebody's turn to do " circuit cuts off and judges subprogram " with regard to inserting every a preset time (being 5ms in the present embodiment).In addition, when input recording commencing signal makes " circuit cuts off and judges subprogram " when just having begun to carry out, as the initial value of this subprogram, all are set in the preceding period T 2 of aftermentioned among the RAM9, last time period T 3, signal flag, instrumentation time t and count value N etc. were set to " 0 " respectively.Also have, when this flow chart of explanation, need to carry out with reference to the sequential chart of figure 2.

When handling transition of operation to this subprogram, at first, the instrumentation of trying to achieve when inserting last time adds the 5ms corresponding to the time of insertion on the time, and this result as this instrumentation time set (step S301) in RAM9.Secondly, judge by the signal level on the telephone line 5 of signal level detection circuit 11 inputs and whether (in the present embodiment be-33dBm) (step S302) greater than predetermined level.At this moment, be not more than-situation of 33dBm, just think that having entered signal stops period, also promptly entered the disconnected period of discontinuous signal, and then a signal flag that is set in the RAM9 is set at " 0 " (step S303), should handle directly end thereafter for signal level.

On the other hand, for the situation of signal level, judge then whether the signal flag has set " 0 " (step S304) greater than-33dBm.At this moment, be not set at the situation of " 0 ", then think it was the signal life period at that time, that is to say the logical period of discontinuous signal, should handle directly end thereafter for the signal flag.In addition, be set at the situation of " 0 ", think that then the discontinuous signal in last control cycle finishes, and this discontinuous signal begun to take place, so transfer to step S305 for the signal flag.

Have, in step S305, the signal flag is set at 1, simultaneously the beginning same period T1 of the instrumentation time t that had before tried to achieve as this instrumentation, be set in the RAM9, this instrumentation time being removed is " 0 " again.In a word, this, period T 1 was exactly that preceding zero hour from discontinuous signal is to the time this zero hour zero hour.

Then, judge try to achieve previously this same period T1 whether within the 250ms-2.5s scope (step S306).At this, for this period T 1 situation in the 250ms-2.5s scope not, thinking that then this discontinuous signal is the discontinuous signal beyond the busy tone, for example is the acoustic information from originator, so the count value N that is set in the RAM9 is cleared into " 0 " (step S307).Thereafter transfer to step S312, last time period T 3 is set in the RAM9 before there previous period T 2 being used as, and simultaneously this period T 1 is used as a preceding period T 2 and is set in the RAM9, and this processing procedure finishes then.

On the other hand, if judge that in above-mentioned steps S306 this period T 1 is within the 250ms-2.5s scope, then judge this period T 1, a preceding period T 2 and last time period T 3 these three same periods the time difference between mutually whether at preset time (being 100ms in the present embodiment) with interior (step S308).That is to say, calculate earlier the time difference of this period T 1 and a preceding period T 2, a preceding period T 2 and last time time difference of period T 3 and this period T 1 and the last time time difference of period T 3 respectively, judge then these calculate three time differences whether all in 100ms.At this, for time difference of three period T 1, T2, T3 not at 100ms with interior situation, judge that then the cycle zero hour of discontinuous signal is dissimilar, so transfer to above-mentioned step S307, count value N is cleared into " 0 ".

In addition, for time difference of three period T 1, T2, T3 all in the 100ms scope with interior situation, the cycle zero hour of then judging discontinuous signal is certain, then on previous count value N, add " 1 ", and this result is set at this count value N (step S309).Whether the count value N that then judges this setting is greater than set-point (being " 3 ") in the present embodiment.(step S310).At this, be not more than the situation of " 3 " for count value N, then transfer to above-mentioned step S312, period T 3 last time before previous period T 2 is set at is set at a preceding period T 2 to this period T 1, and this processing finishes then.

On the other hand, if count value N is greater than " 3 ", that is to say if continuous three times are judged that the cycle zero hour of discontinuous signal is certain, think that then this discontinuous signal is the busy tone that sends from telephone exchange, thereby the judgement originator has been hung up receiver, cut off circuit, then transferred to step S311.In step S311, the judgement flag that the representative circuit that is set among the RAM9 is disconnected is set at " 1 "., transfer to above-mentioned step S312, finish this processing thereafter.

By such processing, just judged originator line disconnection, and set the judgement flag for " 1 ".And, when in this " circuit cuts off and judges subprogram ", having set the judgement flag for " 1 ", in the step S106 of the flow chart of above-mentioned Fig. 3, will judge this judgement flag and be set at " 1 ", thereby will send the End of Tape command signal to the CPU24 of recording device 3, make recording device 3 shut-down operations.

As mentioned above, in the present embodiment, when 3 in running order periods of recording device, survey the zero hour of the discontinuous signal that on telephone line 5, transmits, and measure the cycle of this zero hour.And when the beginning of discontinuous signal occurring, three cycles that relatively should institute's continuous measurement before the zero hour just mutually are if the time difference in these cycles within 100ms, judges then that the discontinuous signal cycle zero hour is certain.Have, being judged to be the cycle zero hour for continuous three times is certain situation, thinks that just the discontinuous signal that telephone exchange is sent on the telephone line 5 is a busy-back signal, thereby can judge that originator has cut off circuit again.

In a word, although along with the difference of countries and regions, there are very big difference the frequency of busy-back signal, logical time and break time, and the busy-back signal that sends from telephone exchange always has certain by definite initial cycle in the moment of certain rule.So, if the discontinuous signal of judging on the telephone line 5 has the certain cycle zero hour, and continuous several times is certain all judge this cycle when discontinuous signal occurring and begin, just can judge reliably that this discontinuous signal is not the acoustic information that sends from originator, but busy-back signal.In addition because only survey the cycle zero hour of discontinuous signal, so for all areas, though the frequency of busy-back signal, logical time and break time why, can be detected reliably, thereby judged that correctly circuit cuts off.Consequently, when the originator line disconnection, just can make recording device 3 stop action reliably.Have, this can save trouble and the cost of storing in advance corresponding to the busy tone judgment data of device location again.

Also have, in the present embodiment, be to think that with continuous 3 judgements the cycle zero hour is that certain situation judges that circuit cuts off, judge that necessarily circuit cuts off if replace to judge the cycle for continuous 2 times, though the speed of judging is very fast, the reliability of result of determination is less better.In addition, judge that necessarily circuit cuts off if judge the cycle with continuous 4 times, though then the reliability of result of determination increases, the time that reaches result of determination is elongated.Therefore, consider that with times two aspect that reaches result of determination optimal number of times is 3 times from the reliability of result of determination.Having, in the present embodiment, is to judge by the mutual more continuous cycle of detecting for 3 times whether the cycle is certain again, based on top identical reason, it is optimal that 3 cycles are compared.

Have again, in the present embodiment, be not in situation in the 250ms-2.5s scope for this discontinuous signal that detects cycle that begins, just think that this discontinuous signal is not a busy-back signal, no longer carry out whether certain judgement of cycle.Therefore, suitably exclude the discontinuous signal that is considered to beyond the busy tone might being certain discontinuous signal from the beginning cycle,, thereby can more correctly judge the circuit dissengaged positions for example from the voice message signal of originator.

Also have, the present invention is not limited to the above embodiments, for example might make it specific by following mode.

(1) in the step S310 of shown in Figure 5 " circuit cuts off and judges subprogram ", make when count value for " 2 " or " 4 " when above a judgement flag be set at " 1 ".Also promptly, for the continuous cycle zero hour of judging discontinuous signal more than 2 times or 4 times be certain situation, judge that circuit cuts off.Perhaps, also can allow the operator change the count value N that reaches when judging the circuit dissengaged positions by certain given key of operation.

(2) in the step S308 of shown in Figure 5 " circuit cuts off and judges word program ", judging that whether the cycle zero hour is in certain process, the more continuous mutually cycle that measures more than 4 times.Also have, judging that whether these cycles are in certain process, do not adopt the time difference at 100ms with interior criterion, and change into 120ms with interior or 80ms with interior or 50ms in, as criterion.

(3) in the step S306 of " circuit cuts off and judges subprogram " shown in Figure 5, change the allowed time scope of this period T 1, adopt 250ms-2.5s scope in addition.

(4) in the step S302 of " circuit cuts off and judges subprogram " shown in Figure 5, change the logical time of judgement discontinuous signal or the signal level criterion of break time, take-33dBm level value in addition.

(5) utilize DSP27 to come signal level on the detecting telephone circuit 5.

(6) the present invention is applied on the simple automatic answering telephone that does not possess facsimile function.

About can its effect being described below by the technological thought outside the claim of the foregoing description grasp.

(1) in the communication terminal of being narrated in claim 1, second judgment means is carried out such judgement: the cycle zero hour of judging discontinuous signal when continuous 3 times is a timing, judges that this signal is periodic pulsed sound tone signal.

Like this, number of times being taken as 3 times, cutting off the reliability of this result of determination and reach from circuit and judge required time consideration, is the most suitable.

(2) in the communication terminal of in claim 1, narrating, the cycle of the finish time of measuring device instrumentation signal.

The cycle finish time with the instrumentation signal replaces the cycle zero hour, also can reach purpose of the present invention.

The present invention who is described in detail above utilizing, can bring into play such excellent results, be unnecessary storage in advance and the regional corresponding data that are used for judging busy-back signal of being provided with of device, no matter device is arranged on any area, can detect busy-back signal reliably, correctly determine the circuit off-state.

Claims (6)

1, a kind of communication terminal is characterized by, and it is equipped with: be used for the measuring device in the cycle zero hour of the signal that instrumentation transmits on telephone line; Be used for judging whether this cycle is the first certain judgment means; And to be used for judging this cycle with pre-determined number continuously be one regularly promptly to judge and think that this signal is second judgment means of periodic pulsed sound tone signal.

2, according to the communication terminal of claim 1, it is characterized by, when the zero hour of above-mentioned signal occurring, whether above-mentioned first judgment means cycle of all carrying out is certain judgement.

3, according to the communication terminal of claim 1 or 2, it is characterized by, for by above-mentioned measuring device instrumentation to the situation of signal cycle zero hour position in the 250ms-2.5s scope, whether above-mentioned first judgment means cycle of carrying out is certain judgement.

4, according to the communication terminal of claim 1 to 3, it is characterized by, at least will to by above-mentioned measuring device continuous more than 3 times instrumentation to the signal cycle zero hour compare mutually, when time difference during these weeks during less than preset time, then determination cycles is certain.

5, according to the communication terminal of claim 1 to 4, it is characterized by, when above-mentioned second judgment means judges that the signal that transmits is periodic pulsed sound tone signal on telephone line, just cut off telephone line.

6, according to the communication terminal of claim 1 to 4, it is characterized by, it contains and is used for the recording device of recording to from the acoustic information of originator, and when above-mentioned recording device is in running order, if above-mentioned second judgment means is judged when the signal that transmits on telephone line is periodic pulsed sound tone signal, then stop the action of above-mentioned recording device, cut off telephone line.

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