JPS6322660B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an answering machine, and the present invention relates to an answering machine, in which when a caller hangs up, there are two cases in which there is silence depending on the telephone exchange, there are cases in which there is a continuous tone of "two", and there are two cases in which the caller hangs up.
Taking into account that there may be cases where a repeated "two, two" sound is heard, it is possible to detect as quickly and accurately that the caller has hung up in both cases, and to avoid wasting the message tape. The aim was to minimize the number of cases.

In telephone communications, if a caller hangs up first, a silence, continuous tone, or repeating tone is typically generated on the telephone line by the telephone exchange.

Conventionally, answering machines that detect voice and continue recording have stopped recording when such silence, continuous tone, or repeated tone continues for 5 to 15 seconds, determining that the caller has hung up.

In this case, shortening the required duration to complete detection may cause the inconvenience of false positives or cases in which the caller is confused about what to say, resulting in the line being detected as disconnected. If it is made longer, there is an inconvenience that not only is there a waste of recording time, the tape is wasted, but also time is lost during playback and listening.

For this reason, a method of increasing the detection time and rewinding the recording tape required for detection after detection to eliminate tape waste may be considered. It is difficult to distinguish the words from the repeated sound, so the clock starts counting before the repeated sound is heard, and when rewinding, some of the words may also be rewound.
There is a risk that endings of words may be cut off during playback.

The present invention provides an answering machine that eliminates such inconveniences, prevents malfunctions, and reduces waste of tape.

In other words, the present invention provides a difference in the required detection duration between silent and continuous sounds and repeated sounds, so that repeated sounds with a large amount of information can be detected quickly, so they are short, and silent and continuous sounds with a small amount of information can be detected quickly. Continuous sounds are made longer, and since the latter can be relatively clearly distinguished from words, the message tape is rewound for a certain period of time within the time required for detection, thereby reducing wasted tape.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of an embodiment of an answering machine of the present invention using a microprocessor as a control means. In Figure 1, the station line relay
RLY is open when you are away, and when there is an incoming signal, an AC signal flows to the primary side of the photo coupler PC via capacitor C1, an output current flows to the secondary side, and resistor R1 Generates voltage across both ends. This voltage is input to the microprocessor CPU, and as a result, the CPU
The drive current is output, and the station line relay RLY is
It is turned on, and the office line is connected through the office line relay RLY, the telephone transformer T, and the photocoupler PC, completing the incoming call.

Next, from the CPU, the motor drive transistor Q3
A drive current is output to the transistor Q2 for driving the response message reproducing plunger P1, and the response message is reproduced. This reproduced signal is sent to the calling party via the reproduction head H2, the capacitor C3, the signal amplifier AMP3, and the telephone transformer T. When the reproduction of the response message is finished, the plunger P1 is turned off, and the transistor Q4 for driving the message recording plunger P2 is turned off.
Driven by the output current from the CPU, the message from the caller is sent to the message tape via the office line relay RLY, the telephone transformer T, the signal amplifiers AMP1 and AM2, the capacitor C2, and the recording head H1. Start recording.

At this time, a part of the message signal is amplified by the amplifier AMP4, and then the capacitor C
4. It is rectified by diodes D1 and D2, smoothed by capacitor C5 and applied to resistor R2, and the envelope of the message signal appears across this resistor R2. This is 1 in Figure 2.
Shown below. This envelope signal is passed to the comparator
Reference voltage divided by resistors R3 and R4 in CMP
It is compared with V _TH , and when the envelope signal is greater than the reference voltage V _TH , the output of the comparator CMP becomes high level. This is shown at 2 in FIG. The output of the comparator CMP is input to the analog switch AS as its control signal. This analog switch AS turns on only while the control signal, that is, the output from the comparator CMP, is at a high level, passes the CPU's strobe output, and returns it to the CPU, so the CPU can read the signal 2 in Figure 2. . When this signal consists of random time intervals and durations, the CPU recognizes this as an audio signal, processes it, and continues recording.

However, as shown in 1 in Figure 2, when the caller hangs up at point A and a repeating tone similar to a busy tone appears on the central office line, the output from comparator CMP becomes 2 in Figure 2. As shown, it becomes a periodic pulse signal, and the analog switch AS, which uses this signal as a control signal, also turns on and off in accordance with this period, and controls the CPU.
The strobe output of passes through the analog switch AS only during the ON period of this analog switch AS.
Returned to CPU. Therefore analog switch AS
The signal fed back to the CPU via CMP also has the same period as the output from the comparator CMP. Then, when the CPU detects this periodic signal input via the analog switch AS continuously for a certain period of time t, it determines that the caller has hung up and processes it, turning off plunger P2 and recording. The CPU outputs a current to drive transistor Q5 to drive response message tape rewinding plunger P3 to rewind the response message tape. When rewinding is completed, motor M, plunger P3, and station line relay RLY OFF
Then, the station line is restored and the station returns to standby mode.

In this case, as shown in 2 in Figure 2, if the last part of the business message cannot be distinguished from the repeated sound after the caller hangs up, detection may become faster by Δt. If you perform a rewind operation, there is a possibility that the caller's message will be engulfed by Δt as shown in 2 in Figure 2. may disappear.
Therefore, if a repeating sound is generated when the phone is hung up, rewinding is not performed and only recording is stopped. Note that in order for the CPU to determine that it is a repetitive sound and process it, it usually only needs to be repeated 4 to 6 times, and can usually be set to about 5 seconds.

On the other hand, depending on the exchange, after the caller hangs up, it may send out a continuous tone like a dial tone instead of a repeating tone, or there may be silence, in which case it will be like 3 or 4 in Figure 2. . Considering the variation in the way the caller speaks, the time required to determine whether the sound is continuous or silent is as short as 5 seconds, and preferably 10 to 15 seconds. Therefore, in this embodiment, the detection time for continuous sound or silence is set to be about twice to three times the detection time for repeated signals. If the caller hangs up while recording the message, and the time required for detection of 2t to 3t has passed and it is determined that there is no sound or continuous sound, plunger P2 is activated.
OFF to stop recording, and the CPU outputs a drive current of the transistor Q6 for driving the plunger P4 for rewinding the message tape, thereby rewinding the message recording tape.
Note that the rewind time is set to the time required to rewind the length of the tape that has been fed for the time required to detect silence or continuous sound, and after the set time has elapsed, plunger P4 is turned OFF, and then it is the same as in the case of repeated sound. The central office line is restored by rewinding the response message tape.

As described above, the present invention determines that the line has been disconnected after a first certain period of time when the line is disconnected and there is no sound or continuous sound, and stops recording the business message, and adjusts the distance traveled during the specified period of time. The message tape is rewound by a corresponding amount, and when the line is disconnected and the sound is repeated, recording is stopped after a second fixed time shorter than the first fixed time has elapsed. Therefore, there is no sound.
Accurate detection can be performed in the shortest time depending on whether the sound is continuous or repeated, and moreover, by rewinding the tape in the case of silence or continuous sound, and by shortening the detection time in the case of repeating sound. An excellent effect can be obtained in that waste of tape is reduced, and when the sound is repeated, the end of the message is not cut off due to rewinding. By reducing waste of tape in this way, time loss during playback can also be reduced, so it is especially possible for the telephone owner to remotely control the answering machine from a remote location via the telephone line and send pre-recorded messages. When used in an answering machine with a so-called remote listening function that can be played back and listened to, the effect is extremely large.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of its operation. CPU...Microprocessor, RLY...Station line relay, PC...Photocoupler, AMP1~
AMP4...Signal amplifier, CMP...Comparator, AS...Analog switch, P1...Plunger for playing back the response tape, P2...Plunger for recording and playing back the message tape, P3...Plunger for rewinding the response tape, P4... ...Plunger for rewinding message tape, M...
motor.

Claims (1)

[Claims] 1 A means for recording and reproducing a message tape; a comparing means for comparing the level of a signal arriving on a telephone line with a preset reference level and outputting a comparison result; a first determining means for determining that the caller has hung up by detecting that the silent or continuous sound occurring on the line has continued for a first fixed period; and a first determining means for determining that the caller has hung up the telephone; a second determining means for determining that the caller has hung up by detecting that the repetitive sound occurring on the line has continued for a second fixed period shorter than the first fixed period; When it is determined by the means that the caller has hung up, the recording of the business message tape is stopped, and the business message tape is rewound by a distance corresponding to the first fixed time; Control is performed to wait for the next incoming call at the position where the return is completed, and when the second determining means determines that the caller has hung up, the recording of the business message tape is stopped. An answering machine equipped with a control means for waiting for the next incoming call at a certain location.