JPH0422064B2

JPH0422064B2 -

Info

Publication number: JPH0422064B2
Application number: JP57223931A
Authority: JP
Inventors: Tsunehiro Watanabe
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1982-12-22
Filing date: 1982-12-22
Publication date: 1992-04-15
Also published as: JPS59115672A

Description

[Brief explanation of drawings]

第１図は呼び出し信号検出を行なうフアクシミ
リ装置の要部構成を示すブロツク図、第２図は第
１図中の呼び出し信号検出回路の構成を詳しく示
す回路図、第３図ａ〜ｄ、第５図ａ〜ｄ、第８図
ａ〜ｄは従来のそれぞれ異なる検出方法を説明す
るタイミングチヤート図、第４図、第６図、第９
図は従来のそれぞれ異なる検出方法を説明するフ
ローチヤート図、第７図ａ〜ｅは各国の交換機の
呼び出し信号の説明図、第１０図ａ〜ｄおよび第
１１図はそれぞれ本発明の検出方法を説明するタ
イミングチヤート図およびフローチヤート図であ
る。１……送受信回路、２……呼び出し信号検出回
路、３……主電源起動回路、４……起動要因検出
回路、５……システムコントロール回路、Ｌ……
電話回線、CML……リレー、……検出信号。 FIG. 1 is a block diagram showing the main part configuration of a facsimile device that detects a calling signal, FIG. 2 is a circuit diagram showing the detailed configuration of the calling signal detection circuit in FIG. 1, FIGS. Figures a to d and Figures 8 and 8 are timing chart diagrams explaining different conventional detection methods, respectively, Figures 4, 6, and 9.
The figures are flowcharts explaining different conventional detection methods, Figures 7a to 7e are explanatory diagrams of call signals of exchanges in various countries, and Figures 10a to d and 11 respectively illustrate the detection method of the present invention. FIG. 2 is a timing chart and a flowchart for explanation. DESCRIPTION OF SYMBOLS 1...Transmission/reception circuit, 2...Call signal detection circuit, 3...Main power start circuit, 4...Start factor detection circuit, 5...System control circuit, L...
Telephone line, CML...relay,...detection signal.

Claims

[Scope of Claims] 1. In a calling signal detection method for detecting a calling signal from a line, when a second calling signal is detected after the first calling signal is detected and the signal is off for a predetermined time, A calling signal detection method characterized by determining that a calling signal has been detected. TECHNICAL FIELD The present invention relates to a call signal detection method, and more particularly to a call signal detection method for detecting a call signal by discriminating signals from a telephone line. Prior Art A facsimile device is a typical device that operates by discriminating signals from a telephone line and detecting a calling signal. The configuration is shown in FIG. 1 and will be explained. In the figure, the symbol L indicates a telephone line, and its connection terminals L ₁ and L ₂ are switchably connected to the connection terminals T ₁ and T ₂ of the telephone T and the transmitting/receiving circuit 1 that performs transmission and reception via a relay CML. A calling signal detection circuit 2 for converting signals from the telephone line into detection signals is connected to the connection terminals T ₁ and T ₂ . At the subsequent stage of the call signal detection circuit 2, a main power supply startup circuit 3 that turns on the power and starts the device, a startup factor detection circuit 4 that detects a startup factor of the device, and a system control circuit 5 that is a control section are connected in parallel. The activation factor detection circuit 4 is connected to other activation factors 6 of the device that are not based on the call signal. The system control circuit 5 includes a relay
The CML transmitting/receiving circuit 1, the main power starting circuit 3, and the starting factor detecting circuit 4 are individually connected, and the system control circuit 5 receives the output signals of the calling signal detecting circuit, the transmitting/receiving circuit 1, and the starting factor detecting circuit 4, and Control signals are sent to the relay CML, the transmitting/receiving circuit 1, and the main power supply starting circuit, respectively. With the above configuration, when images are not being transmitted or received, the relay CML is connected to the upper side in the figure under the control of the system control circuit 5, and thereby the telephone line L is connected to the calling signal detection circuit 2. When a calling signal arrives on the telephone line L in this state, it is guided to the calling signal detection circuit 2. In the signal detection circuit shown in detail in Figure 2, the call signal is input to the primary side of transformer W via capacitor C1 and resistor R1, and the output from the secondary side of transformer W is input to the base of transistor TR1 via resistor R2. is input. Further, the collector output of the transistor is connected to a time constant circuit consisting of a capacitor C2 and a resistor R3, and the output of the capacitor C2 becomes the detection signal output of the calling signal detection circuit. A call signal is detected based on this detection signal, and response and image reception operations are performed based on the detection result.The conventional detection method is based on the control flow of the system control unit shown in Fig. 4. , was performed at the timing of each signal shown in FIGS. 3a to 3d. For example, as shown in FIG.
As shown in FIG. 3B, the output of the detection signal becomes low level for approximately 1 second at intervals of approximately 2 seconds in response to the calling signal. When the call signal becomes low level, in response to it, the output of the start signal of the main power start circuit 3 is
As shown in Figure c, it becomes high level and the power is turned on. When the device is started, the system control circuit 5 performs control according to the flow shown in FIG. That is, by first checking whether the output of the activation factor detection circuit 4 that has received the detection signal is due to the detection signal, it is determined whether or not the activation is due to the detection signal (step a1 in FIG. 4). This is based on the detection signal, and if it is determined to be YES, it waits for 2 seconds (step a2). This two-second wait is based on regulations between countries that determine the time from when a call signal is detected to when a response signal is sent. After this standby, the system control circuit 5 sets the control signal of the relay CML to a high level as shown in FIG. Connect to telephone line L and start receiving operation. However, if it is determined in step a1 that the activation is not due to the detection signal, other activation factors are searched for using the output of the activation factor detection circuit 4 (step a4). However, with the above detection method, the detection signal
When the output of the CI simply becomes a roll level, it is determined as a calling signal, and it is not determined whether or not the detection signal has a continuous roll level. Therefore, even if the detection signal momentarily becomes low level due to the impulse of noise from the telephone line L, there is a drawback that it is erroneously detected as a calling signal. In order to eliminate the above drawbacks, a calling signal detection method using the control operation shown in FIG. 6 has been proposed, and the timing of each signal during that time is shown in FIG.
It becomes as shown in . In this detection method, as shown in Fig. 5 a to c,
The device is activated at the same timing of the call signal, detection signal, and activation signal as shown in FIGS. 2a to 2c described above. After startup, it is first determined whether or not the startup was caused by the detection signal (step b1), and if NO is not caused by the detection signal, other startup factors are investigated (step b6); however, if YES is caused by the detection signal, It is determined whether the next detection signal is at a low level (step b2). If the detection signal is low level, the determination is repeated again, but if it becomes high level and the determination becomes NO, a 15 second timer is set (step
b3). Then, it is determined whether the output of the detection signal is at the roll level or not (step b4), and if it is at the roll level and the determination is YES, the control signal of the relay CML is set to high level, and the relay CML is turned on on the transmitting and receiving side to receive the signal. Start operation (step b7)
is at a high level and the determination is NO, it is determined whether the 15 second timer has timed out (step b5). If the timeout has not occurred, the process returns to step b4 and repeats steps b4→b7 or b4→b5, but if the timeout has occurred, the power to the device is turned off and the operation ends. That is, in this method, as shown in FIGS. 5a to 5d, the activation signal is set to high level at the falling edge of the detection signal to low level to perform activation, and then after the detection signal returns to high level, a predetermined signal is activated. Detection signal again within time (here within 15 seconds)
When CI becomes low level, it is recognized as a detection signal and the control signal of relay CML is made high level.
A reception operation is started. However, with this detection method, the telephone line L
When two noise impulses are input in succession, the output of the detection signal momentarily becomes low level twice, resulting in erroneous detection as a calling signal. Also, among the calling signals of each country shown in Figures 7a to 7e, there are some in which a single calling signal is further subdivided (see Figure 7c England, Figure 7e Greece), and such calling signals is detected and responded to immediately upon the first call signal, making it impossible to comply with the above-mentioned two-second waiting rule. Furthermore, even when a single ringing signal is not divided in this way, noise impulses on the telephone line L often occur immediately after the ringing signal ends, and even in that case, the telephone responds immediately and does not comply with the above regulations. I can't protect it. In order to eliminate the above drawbacks, a detection method using control shown in FIG. 9 has been proposed. The timing of each signal during this period is shown in FIGS. 8a to 8d. As shown in FIGS. 8a to 8d, after activation is performed in the same manner as in the two examples described above, it is determined whether or not the activation is based on a detection signal (step c1) in the same way as steps a1 and b1 described above. If so, search for other activation factors (step c7). If it is determined to be YES, a 0.5 second software timer is set (step c2), and then it is determined whether the output of the detection signal is at a low level (step c3). If the determination is NO, the main power startup circuit 3 is controlled to turn off the power to the device (step c8), but if the determination is YES, it is determined whether the software timer has timed out (step c8). c4). If NO, the process returns to step c3 and performs the determination operation of step c3 again. That is, in the loop of steps c3, c4, and c7, the power of the device whose output of the detection signal becomes high level for 0.5 seconds is turned off. If the output of the detection signal is at a low level for 0.5 seconds or more, the determination in step c4 becomes YES after repeating steps c3 and c4, but in that case,
Wait for another 2 seconds (step c5), and then set the output of the control signal of relay CML to a high level as shown in Figure 7d, thereby causing relay CML to
Turn on the transmitter/receiver circuit 1 side. That is, in this detection method, if the output of the detection signal continues for a predetermined period of time (0.5 seconds in this case) or more, it is determined as a calling signal, so that impulses of noise on the telephone line will not be mistakenly detected as a calling signal. By the way, the previously mentioned Figure 7c UK, Figure 7e
One call signal is further subdivided, such as the call signal of an exchange in Greece, etc., and the duration of each subdivided signal unit is very short, and the duration is the predetermined time of 0.5 seconds mentioned above. If it is shorter, this detection method cannot detect it as a calling signal. Purpose The present invention has been made in view of the above-mentioned problems, and aims to provide a ring signal detection method that can prevent false detection of ring signals from a line and can handle the detection of various ring signals. do. Embodiment The method of the present invention will be described below with reference to FIGS. 10 and 11, using the above-mentioned method for detecting a paging signal of a facsimile machine as an embodiment. FIG. 10 is a timing chart of each signal according to the method of the present invention, and FIG. 11 is a flow chart showing the control operation of the system control section of the facsimile apparatus according to the method of the present invention. When the same calling signal as in the prior art example shown in FIG. 10a is input from the telephone line L to the calling signal detection circuit 2, the output of the detection signal of the calling signal detection circuit 2 is as shown in FIG. 10b. Similarly, it becomes low level intermittently in response to a call signal. In the method of the present invention, as shown in FIG. 10c, the detection signal is not at the falling edge where it first becomes low level, but at the rising edge when it returns to high level after once becoming low level, as shown in FIG. 10c. The output of the activation signal from the power source activation circuit 3 becomes high level, the power is turned on, and the device is activated. When startup is performed, the system controller unit 5
determines whether or not the activation is due to the detection signal (step d1), and if the determination is NO regardless of the detection signal, examines other activation factors (step d6)
However, in this case, since it is based on the detection signal, the determination is YES and the process waits for 1 second (step d2). During this one second standby, the system controller section 5 does not react to changes in the output level of the detection signal.
In other words, detection is interrupted. After waiting for 1 second, a 15 second timer is set (step d3), and it is determined whether the output of the detection signal is low level or not (step d4). If it is low level and the determination is YES, the relay is activated. Set the CML control signal to high level and turn on the relay CML on the transmitting and receiving side to start receiving operation (step d7)
is at a high level and the determination is NO, it is determined whether the 15 second timer has expired (step
d5). If the timer has not run out, the process returns to step d4 and repeats steps d4→d7 or d4→d5, but if the timer has run out, the device is powered off and the operation is completed. That is, according to the method of the present invention, the device is activated when the detection signal once goes to low level and then returns to high level. When the signal becomes low level, it is determined that it is a call signal, and relay CML is turned on on the transmitting and receiving side to start receiving operation. According to this method, the control signal of relay CML is set to high level at the second falling edge of the detection signal, as shown in FIG. 10d. According to this method, when a call signal arrives, there is a detection interruption time of 1 second after the end of the first call signal, so the influence of noise impulses that almost always occur immediately after the end of the call signal is eliminated, and the first call signal ends. This prevents the user from responding immediately after the end of the first call signal. Furthermore, it is determined as a calling signal by detecting the falling edge of the next detection signal after a detection interruption time of 1 second.As shown in Figures 7a to 7e, the interval between the calling signals in each country is 2. Since it is longer than 2 seconds, the above-mentioned rule of waiting for 2 seconds can be observed. Furthermore, since detection is performed at the rising edge and falling edge of the detection signal during the 1-second detection interruption time, one call signal is subdivided and the signal duration of each subdivided unit is short. can also be detected. Further, when a noise impulse is input from a telephone line, even if the impulse is not a single one, the interval time between the plurality of impulses is very short, so that they are not detected as a calling signal. In the above embodiments, the method for detecting a ringing signal of a facsimile machine was used as an example, but it is applicable to a type of equipment that distinguishes and detects a ringing signal from a signal from a telephone line and performs some operation in response to the detected ringing signal. The method of the present invention can be applied to all. Effects As described above, according to the present invention, when a second ringing signal is detected after detecting the first ringing signal and then detecting the off state of the signal for a predetermined period of time, it is determined that the ringing signal has been detected. Since the determination is made, it is possible to prevent erroneous detection of a calling signal due to noise, and it is also possible to cope with the detection of various calling signals.