JPS5926959B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital electronic musical instrument that synthesizes musical tones by controlling each harmonic coefficient using means for externally changing harmonic coefficients, particularly drawbars.

Conventionally, a tone wheel generates a sine wave sound source,
There is a system in which musical tones are synthesized by controlling each harmonic by operating drawbars.

This method has drawbacks such as the need to provide a tone generator for each harmonic, and the fact that the overtones are not true harmonics (-) resulting in some dissonance in the sound. In response, an electronic musical instrument without these drawbacks was proposed by developing a harmonic synthesis method using a digital method.

U.S. Patent Application No. 3809786 (Japanese Unexamined Patent Publication No. 48-9
0217) describes an electronic organ that is calculated in real time using a harmonic synthesis method.

Also, U.S. Application No. 6033776 (Japanese Unexamined Patent Publication No. 51-9
3519) does not require real-time calculations.
When calculating the waveform, for example, the electronic organ presented in U.S. Application No. 3,809,786 (Japanese Unexamined Patent Publication No. 48-90217) uses the 32nd pitch for the C7 note. For a single channel circuit that generates up to harmonics, the clock frequency is 4.29MH2
It has to be ℃・.

Also, U.S. Application No. 6033776 (Japanese Unexamined Patent Publication No. 51-9
3519), the clock frequency is approximately 1MHz (
1.1352 MHz).As shown in the above, even in the case of (• deviation, the calculation speed for calculating the waveform is very high.

The external control readout by the drawbars is also performed in synchronization with this high-speed clock. However, it is not necessary to read information from the first drawbar using such a high-speed clock, and it is easier to design if it is processed at a lower speed.
It is also advantageous in terms of reliability and price.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic musical instrument using a musical tone synthesis method in which harmonic coefficient control by a drawper is performed at low speed.

To achieve the above object, the electronic musical instrument of the present invention synthesizes musical tones by multiplying and adding harmonics and harmonic coefficients or values equivalent to these, and selectively changes the harmonic coefficients from the outside. means for detecting the change at a speed slower than the calculation speed for synthesizing musical tones; a storage circuit for storing the detected change as a harmonic coefficient at the slow speed; The present invention is characterized in that it includes a circuit that reads harmonic coefficients stored in the memory at a calculation speed required for synthesizing musical tones and synthesizes musical tones.

The present invention will be described in detail below with reference to examples. FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention, and is an explanatory diagram showing the configuration of an embodiment of the present invention, and is
This is a modified configuration based on the electronic organ disclosed in No. 786 (Japanese Unexamined Patent Publication No. 48-90217).

Note that the same numbers are assigned to the same parts as in the above proposed example. The harmonics are sequentially read out in synchronization with the clock pulse T (for example, 4.29 MHz) and input to the multiplier 33.On the other hand, the drawbars 203 are manually operable variable resistor type drawbars each corresponding to each harmonic. For example, it is provided with nine drawbars, 203-A is the first harmonic, 203-B
is the second harmonic, 203-C is the third harmonic, etc.
...203-1 corresponds to the 16th harmonic. Next, each output voltage of the drawbars 203 is inputted to an analog type multiplexer 204, and the analog type multiplexer 204 clocks the output voltage of each of the drawbars using a low frequency clock 201 (for example, 1 KHz) different from the main clock 20. Convert to split signal and output. The output of the analog multiplexer 204 is input to the AD converter 205, and the AD converter 205 converts the analog signal into a digital signal. The output of the AD converter 205 is then input to a buffer memory 206 having a memory capacity corresponding to each drawbar 203. That is, the AD-converted outputs are sequentially stored at predetermined addresses in the buffer memory 206 by applying a low frequency clock from the clock 201 by the memory address control circuit 202 in synchronization with the time division of the drawbar from the analog multiplexer 204. . In this way, the harmonic coefficient determined by the drawper 203 is directly stored in the buffer memory 206. The harmonic coefficients stored in buffer memory 206 are:
Next, in response to the high-speed clock of the main clock 20 by the memory address control circuit 202, the signal is read out from the sine wave function table 29 in synchronization with each harmonic read out according to the main clock 20, and is read out by the multiplier 33. Multiplied by the corresponding harmonic.

Next, each harmonic component is accumulated and outputted by an accumulator 16. The output of the accumulator 16 is then converted into an analog signal by the DA converter 18 and input to the audio device 11. FIG. 2 is an explanatory diagram showing the configuration of another embodiment of the present invention. The difference from the embodiment shown in FIG. 1 is that the AD converter 2
05 and the buffer memory 206.
1 has been newly established. That is, as in FIG. 1, the output voltage of each drawbar 203 is input to an analog multiplexer 204, where each drawbar 203 is inputted by a low frequency clock 201 different from the main clock.
converts the output voltage into a time-division signal and outputs it. The output of the analog multiplexer 204 is input to the AD converter 205, and the AD converter 205 converts the analog signal into a digital signal. The output of the AD converter 205 converted into a digital signal is then sent to a newly installed data converter 211.
is input to. When the data converter 211 uses a variable resistance type drawer 203,
There is a case where the resistance change characteristic of 203-1 does not match the required change characteristic of the drawbar.

In this case, the AD-converted value from the variable resistor is further converted into data to obtain the desired change characteristics of the drawbar.
・Can be done. The output of the data converter 211, which has been converted into the desired characteristics in this manner, is input to the buffer memory 206, where harmonic coefficients corresponding to changes in the drawbar are stored. The harmonic coefficients stored in the buffer memory 206 are then transferred to the main clock 2 by the memory address control circuit 202.
0 high-speed clock, it is read out from the sine wave function table 29 in synchronization with each harmonic read out according to the main clock 20, and is multiplied by the corresponding harmonic by the subtracter 33.

Next, each harmonic component is accumulated and outputted by an accumulator 16. The output of the accumulator 16 is then converted into an analog signal by the DA converter 18 and input to the audio device 11. As shown in the embodiments of FIG. 1 and FIG. A system is adopted in which the contents of the drawbar 203 are stored in the buffer memory 206. Therefore, the AD converter 205 should be used for low speeds, and one that is low in price and has high reliability can be applied. This also applies to scanning systems, etc., and the circuit configuration FIG. 3 is an explanatory diagram showing the configuration of still another embodiment of the present invention.

In this case, the drawbar 221 includes manually operable multi-contact type drawbars 221-A to 221-1, each having, for example, nine contacts. 221-1 are synchronized with a low frequency clock different from the main clock 20 from the clock 201, and each drawer 221-A, 22l-B, . . .・・・・・・
, 221-1 are sequentially selected. Each drawbar 221-
The corresponding contacts of A to 221-H are connected to the contact p through the diode D as shown in the circle 230, and the position information of the contact of the drawbar 221 selected by the decoder 224 is transmitted in a time-sharing manner. The data is input to data converter 222 . The data converter 222 stores harmonic coefficients corresponding to the contact positions of the drawbar 221, and outputs the position signals sent from the drawbar 221 after converting them into harmonic coefficients. And Dropa 12
A low frequency clock from the clock 201 is applied to a predetermined address of the buffer memory 206 corresponding to 21 through the memory address control circuit 202 in synchronization with the time division of the drawbar 221, and the harmonic coefficient is stored. The harmonic coefficients stored in the buffer memory 206 are then synchronized with each harmonic read out from the sine wave function table 29 in response to the high speed clock of the main clock 20 by the memory address control circuit 202. is read out and multiplied by the corresponding harmonic by the multiplier 33.

Next, each harmonic component is accumulated and outputted by an accumulator 16. The output of the accumulator 16 is then converted into an analog signal by the DA converter 18 and input to the audio device 11. In this embodiment, information on external control by the drawbar is AD
It is detected as a °C digital signal that does not require conversion, and since the purpose can be achieved sufficiently with a low frequency clock, the circuit configuration is easier than when using a high frequency clock. As mentioned above, the above embodiment has been described as a modification of U.S. Application No. 3809786 (Japanese Patent Application Publication No. 48-90217), but it is
519), and can be applied to a method of synthesizing musical tones by multiplying and adding harmonics and harmonic coefficients or values corresponding to these.

As explained above, according to the present invention, in an electronic musical instrument using a harmonic synthesis method, the position information of the drawbar is transmitted to a clock whose speed is slower than a clock for high-speed waveform calculation. After the data is stored in the buffer memory, readout waveform calculation is performed in synchronization with the waveform calculation clock.

As a result, the position information of the drawbar 1 of the external control means is detected by a low frequency clock, which makes it easy to use an AD converter, especially when the drawbar 1 is a variable resistance type, and even in the case of a multi-contact type, the low frequency clock The circuit configuration is lower and more expensive than the high-frequency processing case in the proposed example.
Gain reliability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention, FIG.
FIG. 3 is an explanatory diagram showing the configuration of other embodiments of the present invention, in which 11 is an audio device, 16 is an accumulator, and 18
is a DA converter, 20 is a main clock, 30 is a memory address circuit, 33 is a multiplier, 201 is a clock, 202 is a memory address control circuit, 203 and 221 are drawbars, 204 is an analog type multiplexer, and 205 is an AD converter. 206 is a buffer memory, 211 and 222 are data converters, 223 is a counter, and 224 is a decoder.

Claims (1)

[Claims] 1. In an electronic musical instrument that synthesizes musical tones by multiplying and adding harmonics and harmonic coefficients or values equivalent to these, means for selectively changing harmonic coefficients from the outside, and synthesizing musical tones. means for detecting the change at a speed slower than the calculation speed for calculating the change; a storage circuit for storing the detected change as a harmonic coefficient at the slow speed; An electronic musical instrument characterized by comprising a circuit that synthesizes read musical tones at a calculation speed required for synthesis. 2. The means for selectively changing the harmonic coefficient from the outside is a circuit that selects the voltage of a manually operable variable resistance drawbar in a time division manner and outputs it as a harmonic coefficient after AD conversion or further data conversion. An electronic musical instrument according to claim 1, characterized in that: 3. The means for selectively changing the harmonic coefficient from the outside selects the contact positions of the manually operable multi-contact type drawbar in a time-sharing manner, and adjusts the harmonic coefficient based on the contact positions outputted in the time-sharing manner. 2. The electronic musical instrument according to claim 1, further comprising an allocating circuit.