JPS5854398A - Chime tone generation circuit - 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 The present invention relates to a chime sound generating circuit that has a relatively simple circuit configuration, is suitable for integration into an integrated circuit, and generates a more natural chime sound.

A conventional chime sound generation circuit has a basic oscillation circuit that oscillates one reference frequency, and this frequency is divided to create the chime sound frequency, chime sound modulation waveform, chime sound tempo, etc. , it is known to create a chime sound by combining these. However, such a chime sound generation circuit has a complicated configuration, and it is
C), there are disadvantages in that the wafer/'% area increases, the RC unit price increases, and it takes time to design the IC. In addition, because a 3- to 4-bit step-like chime sound modulation waveform obtained by dividing the above reference frequency is used, the amplitude change of the generated sound is discontinuous, linear, and natural. However, in order to produce natural sounds in such a circuit, it was necessary to increase the number of stages (bits), which led to the disadvantage that the circuit configuration became increasingly complex.

The purpose of the present invention is to solve the above-mentioned problems in the conventional type.
In the chime sound generation circuit, a basic oscillation circuit for oscillating the frequency for the chime sound and an oscillation circuit for generating the modulation waveform of the chime sound are provided separately, and the idea is to use the charge/discharge curve of a capacitor as the modulation waveform.
To provide a chime sound generation circuit which has a simple circuit configuration, is suitable for IC implementation, and generates a natural chime sound.

The present invention will be described in detail below using the drawings.

FIG. 1 is a circuit diagram of a chime sound generating circuit according to an embodiment of the present invention. In the figure, 1 includes an input switching circuit that detects a push operation of an externally connected pushbutton switch 2 and outputs a button-on signal, 3 includes a power control switch 31 such as a transistor, and a constant voltage circuit 32.
a power supply section that supplies a constant voltage VD from the power supply [not shown] voltage Vc to all circuits by pressing the push button 2;
4 is the first one for setting the timing of the operation of each part of the circuit.
~A timing pulse generation circuit that generates a third pulse;
5 is a power supply latch circuit that turns on the power supply control switch 31 and latches the power supply while a chime sound is being generated based on the count value of a counter 9, which will be described later; 8 is a reset circuit that resets the counter 9 based on the 7-digit first timing pulse and the output of the counter 9, which will be described later. A push button signal lock circuit that locks the push button on signal, such as a flip-flop, a counter that counts the period of a 9-digit chime modulation waveform generation circuit and drives a power supply latch circuit and a frequency switching circuit based on the count value, and a 10-digit chime modulation waveform generation circuit. a pulse conversion circuit that converts the rising edge of the output of No. 12 into a pulse, No. 11;
12 is a second delay drive circuit that delays the output of the push button lock circuit until a third timing pulse is input; 12 is a chime modulation waveform generation circuit that operates based on the output of the second delay drive circuit; 13 is a sawtooth wave generation circuit using electric discharge; 13 is a modulation prohibition switch that prohibits or allows transmission of the output of the chime modulation waveform generation circuit to the output modulation section 17 based on the count value of counter 9; 14 is a transistor, for example; A frequency switching circuit that switches the basic oscillation circuit 150 frequency by, for example, switching the time constant based on the output of the counter 9; 15 is a basic oscillation circuit;
17 is a waveform shaping circuit that shapes the output waveform of the 16Vi basic oscillation circuit and outputs, for example, a rectangular wave; 17 is an output modulation section that amplitude-modulates the output of the waveform shaping circuit with the output of the chime modulation waveform generation circuit 12 and outputs a chime sound; For example, it is a class 0 amplifier that takes the output of a waveform shaping circuit as an input and clips it with the output of a chime modulation waveform generation circuit.

Next, the operation of this chime sound generating circuit will be explained. When the pushbutton switch 2 is pressed, the input switching circuit 1 detects this and generates a pushbutton on signal, and the power supply unit 3 turns on the power supply control switch 31 to transfer the power supply voltage VC to the constant voltage circuit. 32 as a voltage VD to all circuits. The timing pulse generation circuit 4 generates pulses at three timings when the voltage Vjl is applied. First, when the first timing pulse is generated, the clear signals of the reset circuit 7 and the push button signal lock circuit 8 are released.

Next, when the second timing pulse occurs, the first delay drive circuit 6 operates the reset circuit 7 and the pushbutton signal lock circuit 8 based on the pushbutton ON signal of the input switching circuit 1.
, reset circuit 7 and push button signal lock circuit 8
is set, the clear signal of the reset circuit 7 counter 9 is released, and the push button lock circuit 8 locks the push button ON signal and sends it to the second delay drive circuit 11. Subsequently, when the third timing pulse is generated, the chime modulation waveform generation circuit 12 inputs the locked push button on signal via the second delay drive circuit 11, starts oscillation, and output modulates the chime modulation waveform. 17 and the pulse conversion circuit 10. The pulse conversion circuit 10 converts the chime modulated wave into a pulse and sends it to the counter 9. When the counter 9 inputs the first pulse at the same time as the chime modulation waveform generation circuit 12 starts oscillating and counts N1'', it turns on the modulation prohibition switch 13 to allow modulation, and sends the signal "1" to the frequency switching circuit 14. The frequency switching circuit 14 receives the signal 1111+ from the counter 9, and changes the frequency of the basic oscillation circuit 15 to "0" at the first chime sound point.
Switch to a frequency (for example, 900 Hz) that corresponds to the "ping" sound. The output of this basic oscillation circuit 15 is the waveform shaping circuit 1
After being shaped in step 6, it is input to the output modulation section 17, where it is amplitude-modulated using the separately input chime modulation waveform as described above, and the "ping" sound in the first half of the chime sound is output. Next, when the output of the chime modulation waveform circuit 12 enters the second cycle, the pulse conversion circuit 10 generates the 21-th pulse at the rising edge of this output, and the counter 9 counts '2''. When the signal ``2'''' is received from 9, the frequency of the basic oscillation circuit 15 is switched to a frequency (for example, 760 Hz) corresponding to the "ping" sound at the second chime sound point. The output of the basic oscillation circuit 15 is shaped by the waveform shaping circuit 16, as described above, and then output by the output modulation section 17.
The chime modulation waveform that is input separately is used to amplitude-modulate the chime modulation waveform, and the "ping" sound in the latter half of the chime sound is output. Furthermore, the output of the chime modulation waveform generation circuit 12 is
At the beginning of the cycle, the pulse conversion circuit 1 is activated at the rising edge of this output.
0 generates the third pulse, and the counter 9 counts 3''. When the counter 9 counts 3'', the modulation prohibition switch 13 is turned on to prohibit modulation, and the power supply latch circuit 5 is activated. Solve. As a result, the power on/off switch 2 is opened and the voltage VD becomes zero, and the chime sound generation circuit completes the generation of a series of chime sounds.

As described above, according to the present invention, by providing the basic oscillation circuit and the chime modulation waveform generation circuit separately, the circuit configuration is simplified, and when integrated into an IC, the wafer area can be reduced and the IC unit price can be reduced. In addition, it is suitable for IC implementation as it can reduce the time and cost of IC design.Furthermore, the chime modulation waveform can generate a continuous and exponential sound that is closer to nature than the capacitor's charge/discharge curve. .

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a chime sound generating circuit according to an embodiment of the present invention. l... Input switching circuit, 2...
Electricity m, section, 3...constant voltage circuit, 4...
Timing pulse generation circuit, 5...Power supply latch circuit, 6...First delay drive circuit, 7...
... Reset circuit, 8 ... Push button signal lock circuit, 9 ... Counter, 10 ... Pulse conversion circuit, 11 ... Second delay drive circuit, 1
2... Chime modulation waveform circuit, engineering 3...
- Modulation prohibition switch, 14... Frequency switching circuit, 15... Basic oscillation circuit, 16... Waveform shaping circuit, 17... Output modulation section, 31 ...
...Power control switch, 32... Constant voltage circuit. Patent applicant: Toshiba Electric Materials Corporation〃 ROHM Co., Ltd. Agent: Patent attorney Tatsuo Ito〃 〃 Tetsuya Ito

Claims (1)

[Claims] 1. A power supply unit that is activated by pressing the chime button and supplies constant voltage to each circuit, a basic oscillation circuit that generates the frequency of the chime sound, and a modulation waveform generator that generates the modulation waveform of the chime sound. an output modulator that modulates the amplitude of the output of the basic oscillation circuit using the output of the modulation waveform generator and outputs the amplitude-modulated output; and a frequency switching circuit that switches the frequency of the basic oscillation circuit to the frequency of the first and second dots of the chime sound. ,
a power supply latch circuit that latches the power supply, a counter that counts the output of the modulation waveform generation circuit and drives the frequency switching circuit and the power supply latch circuit based on the count value, and an initial state setting section that sets the initial state of the circuit; 1. A chime generation circuit comprising: a timing pulse generation circuit that emits a pulse that sets the timing of an operation.