JPH0219514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a calling device, and particularly to a variable sound pressure level device thereof.

Generally speaking, selective calling devices and individual calling devices often notify the carrier of a call by emitting a tone at an audible frequency from a sounding body. Now, regarding the ringing volume, it is desirable to make it as loud as possible if you want to be sure to be notified of a call, but on the other hand, if the person on the phone is in a quiet place, the ringer will suddenly ring at a loud volume. This destroys the atmosphere and is often inconvenient. In such cases, for example, a volume is installed that allows the output volume to be adjusted in advance.

The present invention proposes a calling device in which the output itself gradually changes from a low volume to a high volume, and when the bearer confirms the call and operates a ringing reset button, the call stops.

An embodiment of the present invention will be described below based on the drawings. Since the sounding body for notifying the call of the calling device is made small, the sound output generally has frequency characteristics as shown in FIG. The x-axis is frequency, y
The axis is sound pressure. The maximum sound pressure is shown at resonance point A of the sounding body. Usually, the sounding body is designed so that the resonance point A is located at a desired frequency, that is, the maximum sound pressure is achieved. Therefore, the sound pressure gradually decreases at points (B), for example, where the resonance point (A) is removed.

When a device receives a call using this feature,
First, a sound is generated at the frequency of point B, which is shifted from the resonance point A.
By gradually increasing the frequency and varying the input frequency of the sounding body so that the sound is finally produced at the frequency of resonance point A, the output sound pressure is gradually increased along the y-axis in Figure 1. Can be done.

Furthermore, a major feature of the present invention is that when varying this frequency, digital logic processing can be performed as described below. If the oscillation circuit of the calling frequency is composed of a MOS integrated circuit,
Even if the circuit becomes somewhat more complex, there will be no major difference in IC manufacturing costs due to advances in integration technology. Rather than adding external volumes, resistors, and capacitors to unnecessarily increase the number of components as seen in conventional circuits,
The effect is great.

First, the manner in which the frequency is varied will be explained with reference to FIG. This diagram shows that the sound frequency that drives the sounding body is
It shows how things change over time. In FIG. 2a, it is assumed that the sound starts at a certain time _t1 . As already explained, when the sound starts, the sound pressure starts at a sufficiently low level so as not to give an unpleasant sensation to the person carrying the device. Equivalent to. At time t ₂ after a certain period T ₁ has elapsed, the sound frequency is switched from frequency ₁ to frequency ₂ in order to slightly increase the sound pressure level. The time t ₃ after which a further period T ₂ has elapsed
Then the sound frequency changes from frequency ₂ to frequency ₃ , and the period T ₃
At time t ₄ , the sound frequency changes from frequency ₃ to
₄ , and at t ₅ after the period T ₄ has elapsed, the sound frequency switches from frequency ₄ to _{frequency 5} . In this case, ₅ is the resonance frequency of the sounding body, which corresponds to point A in Figure 1. The ringing continues until the person carrying the device confirms the ringing and presses the reset button to stop the ringing. Figure 2b shows a method in which the maximum sound pressure level at the resonance frequency of the sounding body is divided into _five levels, starting from the low sound pressure level at the start of the sound, and gradually increases as time passes. .

In small sounding bodies used in receivers with selective calling devices, the resonance frequency ₅ is often 2666 Hz.

At this time, it seems appropriate to set ₁ to 1067Hz, ₂ to 1333Hz, ₃ to 1600Hz, _{and 4} to 2133Hz, and set T ₁ = T ₂ = T ₃ = T ₄ = about 2 seconds.

A basic block diagram of the present invention is shown in FIG. An oscillation circuit 1 oscillates a fundamental frequency, and a frequency divider circuit 2 divides the frequency into a required frequency. The paging detection circuit 5 samples the DISC.OUT signal 6 obtained by demodulating the paging signal sent from the radio line, detects whether it is calling itself, and outputs a paging output signal. The frequency switching circuit 3 starts with the ringing output signal, counts clocks, sequentially generates switching signals, and controls the switching period and ringing time of the frequency input to the sounding body. The variable frequency circuit 4 switches the frequency input to the sounding body according to the time interval determined by the frequency switching circuit 3. When the call detection circuit 5 detects a self-call, the variable frequency circuit 4 switches the frequency as shown in FIG. 2, causes the sounding body to sound, and the sound is stopped by a reset signal 7 from an external reset button. This circuit is composed of a simple digital circuit.

Next, a specific circuit is shown in FIG. The oscillation circuit 1 oscillates at a fundamental frequency _{of 0} . In the frequency dividing circuit 2, clocks of, for example, 0.5 Hz and 64 LHz are created for frequency switching period of 2 seconds and variable frequency generation. The 0.5Hz clock is input to the frequency switching circuit 3. Frequency switching circuit 3 is decimal counter 1
0 and a decimal decoder 11, which decodes the value of the counter 10 and outputs the variable frequency circuit 4.
Enter. The variable frequency circuit 4 includes frequency divider circuits 12 to 16, which are divided by 5, divided by 3, divided by 2, divided by 2, and divided by 2, and changes the frequency division by a decode signal inputted from the frequency switching circuit 3. When the value of the counter 10 is 0, that is, during T ₁ , the 64KHz clock is passed through the frequency divider circuits 12, 13, 14 to 1/51/3, 1/2.
The frequency is divided and a 2.133KHz output is output from the gate 19. When the value of counter 10 becomes 1 after 2 seconds,
The 64KHz clock is input to the divide-by-3 circuit 13 through the gate 17, where the frequency is divided by 1/3, and then to the divide-by-2 circuit 14,
The frequency is divided into 1/2, 1/2, 1/2 through 15 and 16,
Outputs 2.666KHz output to gate 21. Similarly, when the value of counter 10 becomes 2 or 3, each becomes 1/20.
The frequency is divided by 1/15 and outputs 3.2KHz and 4.267Hz. When the value of the counter 10 becomes 4, the 64KHz clock is input to the divide-by-3 circuit 13 through the gate 17.
The frequency is divided into 1/3, and the frequency is divided into 1/3 through the divide-by-2 circuits 14 and 15.
The frequency is divided by 2.1/2 and a 5.333KHz output is output to the gate 18. Also, when the value of count 10 becomes 4,
The gate 22 prohibits input to the counter 10, and the counter 10 holds 4 until the reset button is operated. Each output is ORed by a gate 21 and further divided by 1/2 by a frequency divider circuit 23 to output ₁ = 1067 Hz, ₂ = 1333 Hz, ₃ = 1600 Hz _{, 4} = 2133 Hz, ₅ = 2666 Hz. In order to set the duty of the output pulse to 1:1, a divide-by-2 circuit 23 is provided at the final stage.

The frequency switching circuit 3 and the frequency variable circuit 4 are
Since it is called by the DISC.OUT signal 6, it is latched in the flip-flop 24 and starts operating. This can be canceled by operating the reset button. Therefore, after each 2-second beep for ₁ to ₄ , the beep for ₅ continues until the reset button is pressed. Further, the variable frequency circuit 4 can be easily constructed by using an up-down counter or the like instead of being constructed from a frequency dividing circuit array as shown in FIG.

The above description shows an example of a specific logic circuit that varies the sound frequency over time in order to vary the sound pressure. In the selective calling device,
Generally, the call detection circuit 5 shown in FIG. 3 includes a logic circuit. Therefore, if the circuit contents are as shown in FIG. 4, the chip area will not be increased excessively when integrated. In particular, if the oscillation circuit 1 of FIG. 3 is made the same as the logic clock controlling the call detection circuit 5, the system can be further simplified.

Figure 5 shows an FM receiver with a selective calling device using this device. An FM signal modulated by a selective calling signal is received by an antenna 31, amplified by a receiving section 32, and transmitted to a demodulator 33. The demodulator 33 demodulates the selective calling signal from the incoming FM signal and outputs the signal as shown in FIG.
Output as DISC.OUT signal (discriminator output). The call detection circuit 34 compares the call number with its own call number stored in the call number storage circuit 35, and if the numbers are the same, it informs the ringing control circuit 36 of the same number. The sound control circuit 36 referred to here includes the elements indicated by the broken line in FIG. 3, which have been described as the present invention. Therefore, the sound output signal changes its oscillation frequency over time and is transmitted to the sound amplification circuit 37. The sound signal is amplified here and causes the sounding body 38 to sound. A person carrying an FM receiver with a selective calling device becomes aware of his/her own call as the ringing tone gradually becomes louder. After confirming the call, the carrier presses the ring reset button 40. As already explained here, if the ring detection circuit 34 and the oscillation circuit 39 that controls the sound control circuit 36 are the same, and the broken line portion in FIG. 5 is integrated into the same circuit, the chip It is possible to configure a sound frequency variable circuit with fewer external components without significantly increasing the area.

As described above, according to the present invention, since the ringer volume is varied, the person carrying the ringer can confirm the ringer when the ringer volume reaches a level that corresponds to the level of noise in the environment. All inconveniences can be resolved. Moreover, by using a sounding body with frequency characteristics and increasing the frequency of the signal applied to it in steps at predetermined time intervals, a low-frequency, low-volume sound is produced at first, and then a high-frequency, high-volume sound is produced. The advantage of this system is that it starts with a low sound and volume, not only in noisy places but also in small, quiet places, so you can easily receive calls without bothering others. has. According to the present invention, it is possible to change the volume at the same time by changing only the frequency, so the overall circuit configuration can be relatively simple and can be easily configured with a logic circuit using IC technology. It has the advantage of being able to

[Brief explanation of drawings]

FIG. 1 is a sound output characteristic diagram of the sounding body, FIG. 2 is an explanatory diagram showing how the sound frequency that drives the sounding body changes, and FIG. 3 is a basic block diagram showing an embodiment of the present invention. FIG. 4 is a detailed circuit diagram thereof, and FIG. 5 is a block diagram of an FM receiver with a selective calling device using the device of the present invention. 1... Oscillation circuit, 2... Frequency dividing circuit, 3... Frequency switching circuit, 4... Frequency variable circuit, 5... Call detection circuit.

Claims (1)

[Claims] 1. A sounding body having frequency characteristics, a call detection circuit that detects when a received call signal is a call to itself and outputs a call output signal, and a clock that is started by the call output signal. a frequency switching circuit that generates a switching signal for sequentially changing the frequency in steps at predetermined time intervals, and is reset by operating a reset button; A variable frequency circuit is provided which switches the frequency step by step at predetermined time intervals, so that when a call is received, the sounding body first sounds at a low frequency and a low output, and then the frequency changes step by step at a higher frequency at predetermined time intervals. , a calling device configured to change the frequency and sound pressure to produce a large output.