JP3245411B2 - Electronic musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument, and more particularly to control of a harmonic coefficient in a tone generator using a sine synthesis method.

[0002]

2. Description of the Related Art In a conventional electronic musical instrument, a plurality of harmonics of a musical tone of a certain timbre are respectively generated by a sine synthesizing method and synthesized to obtain a musical tone signal of a desired timbre. Was. In this sine synthesizing method, in order to synthesize a musical tone waveform whose timbre changes over time, each harmonic coefficient of a reference harmonic coefficient set is modulated by an envelope that changes over time, or There was a method of correcting by a formant filter that changes with time.

[0003]

In the conventional electronic musical instrument of the sine synthesis method as described above, one musical tone is generated by dividing a reference harmonic coefficient into an element for modulating the harmonic coefficient with time. The amount of data needed to
It is much less than a PCM (waveform storage) sound source,
For example, there is a problem that it is necessary to provide an envelope operation circuit for controlling each harmonic coefficient. An object of the present invention is to improve the problems of the prior art as described above,
It is an object of the present invention to provide an electronic musical instrument that can easily obtain a temporal change in timbre of a tone signal generated by sine synthesis without providing an envelope arithmetic circuit or the like and can also generate a continuous tone without timbre change. .

[0004]

SUMMARY OF THE INVENTION The present invention relates to an electronic musical instrument for synthesizing a musical tone based on harmonic coefficient set information that differs for each tone color. A harmonic coefficient set storing means for storing a plurality of harmonic coefficient sets corresponding to a part; and a designation for designating a harmonic coefficient set to be sequentially read from the harmonic coefficient set storing means in accordance with a selected timbre. Repeat reading of information and each harmonic coefficient set
A sequence storage means for storing the number of times, based on the key information and the specification information has been read is <br/> from the sequence memory means in response to tone color information, the designated harmonic coefficient sets said sheet - The read cycle read from the case storage means
After reading the same number of times , the next harmonic coefficient set
A read address generating means for designating a read address of the sequence storage means so as to be read, and a tone signal generating means for generating a tone signal based on the read harmonic coefficient set information. And Further, according to the present invention, the harmonic coefficient set is sequentially read from the harmonic coefficient set storage means.
Specifying the harmonic coefficient set to be specified and each harmonic
Sequence for storing the coefficient set readout repeat count
Read from the sequence storage means.
Based on the specified information and the read number of repetitions, harmonic coefficient set to be read from the harmonic coefficient set storage means, number of times sequentially the read repeatedly, and select address generator for repeatedly specified, is read harmonic based on the information of the wave coefficient set, and a musical tone signal generating means for generating a music signal, the select address generator unit, in response to the oN signal generating key information <br/> report, expected from the start of sounding During the time, from the harmonic coefficient set corresponding to the start of the musical tone signal, the harmonic coefficient set is designated in order, and after the elapse of the scheduled time, until the off signal of the key information is generated, The same one harmonic coefficient set is fixedly designated, and a predetermined harmonic coefficient set is successively designated in response to the OFF signal of the key information.

[0005]

According to the present invention, a tone signal is generated by switching the harmonic coefficient at predetermined time intervals according to the elapsed time from the start of sounding or according to the selected timbre by the means as described above. As a result, an arbitrary temporal change of an arbitrary harmonic coefficient (that is, an arbitrary temporal change of a tone color of a generated musical tone) can be easily obtained. In addition, since the same harmonic coefficient set is repeatedly read at a place where the same harmonic coefficient is maintained, an increase in the data amount of the harmonic coefficient set is suppressed. Furthermore, if a specific harmonic coefficient group is repeatedly read by adding a jump function, a sustained tone can be generated with a small amount of data. Further, the present invention can be applied to formant coefficients instead of harmonic coefficients.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a block diagram showing a configuration of an electronic musical instrument to which the present invention is applied. The CPU 1 is a central processing unit that controls the entire electronic musical instrument, such as scanning of keys and switches, key assignment, and sound control, based on a program stored in the ROM 2. The ROM 2 stores a control program, timbre parameters, and the like. RAM3
Is used as a work area, an area for storing tone color parameters set from the panel, various control tables, a MIDI buffer area, and the like are provided. Also R
The AM3 is backed up by a battery, and is configured to be able to retain the set information even when the main power is turned off.

The panel section 4 has various selection switches for tone and the like, a volume, and a display device for displaying characters and figures by means of a liquid crystal, LED and the like. The keyboard unit 5 includes, for example, a keyboard including a plurality of keys each having two switches, and a circuit that scans the state of each switch. As will be described later in detail, the tone generator 6 is a sine synthesis type tone generator which generates and synthesizes a desired tone signal independently for a plurality of channels. The D / A converter 7 D / A converts the digital tone signal. The analog signal processing unit 8 includes a filter circuit for removing noise or the like. The amplifier 9 drives the speaker 10 to amplify the tone signal to emit a tone. The bus 11 connects each circuit in the electronic musical instrument. In addition, a MIDI interface circuit, a floppy disk interface circuit, a memory card interface circuit (all not shown), and the like may be provided as necessary.

FIG. 1 is a block diagram showing a configuration of a tone generator 6 according to one embodiment of the present invention. The selection address generation unit 20 receives key information (key on / off information, tone range, touch information, etc.), timbre information (tone color selection), and a clock signal (X), as will be described in detail later.
1 is supplied with a harmonic coefficient set read address and interpolation calculation data. The harmonic coefficient calculating unit 21 has a built-in harmonic coefficient set memory, which will be described later in detail with reference to FIG. 4. Based on the address supplied from the selected address generating unit 20, two harmonic coefficient calculating units 21 are provided for each harmonic order. The harmonic coefficient is read, an interpolation operation is performed, and a harmonic coefficient set Hq is output. The harmonic memory 22 is a buffer memory capable of storing a harmonic coefficient set in each of two areas A and B. For example, while the harmonic coefficient calculation unit 21 is writing output data in the area A, the area from the area B The written harmonic coefficient set is read out to the waveform calculator 25. The selector 23 is for switching between a write address Wq and a read address Rq output from the execution control circuit 24.

The execution control circuit 24 is a circuit for controlling the operation of the tone generator 6, includes a counter circuit for counting clocks, and generates various timing signals and address signals. Although the details will be described later, the waveform calculator 25 calculates the harmonic coefficient set Hq read from the harmonic memory 22 and the phase information P output from the execution control circuit at the same cycle as the harmonic coefficient calculator 21. Upon input, one cycle of musical tone waveform data (for example, 256 sample values) is sequentially output. The waveform memory 26 has two areas A and B, and each area has a waveform storage area for 32 channels, for example. For example, while the waveform calculator 25 is writing the waveform data in the A area, the previously written waveform data is read from the B area under the control of the read address generation circuit 28.

The read address generation circuit 28, the envelope generator 29, and the multiplier 30 have the same functions as those used in the tone generator of the PCM (waveform storage) system. A read address RA of the waveform memory is generated at an address interval corresponding to a key number (frequency) to be used. Selector 2
Numeral 7 is for switching between the write address WA and the read address RA of the waveform memory 26. The envelope generator 29 generates an envelope signal having a different shape in accordance with a timbre, a tone range, and touch information. The multiplier 30 multiplies the waveform data by the envelope data. In addition,
The tone generator of FIG. 1 performs a time-division multiplex operation,
Two channels of tone signals can be generated simultaneously.
Although not shown, a circuit for adding and synthesizing tone signals of each channel, a sound image effect circuit, an effect adding circuit for reverberation and the like can be provided after the multiplier 30.

FIG. 3 is a block diagram showing the configuration of the waveform calculator 25 in FIG. The read address generator 40 outputs the phase information corresponding to each harmonic order by accumulating the current value information P of the phase of the fundamental wave input from the execution control circuit 24. The sine function table 41 is a memory that stores sine waveform amplitude data for one cycle (for example, 256 sample values).
The amplitude value of the sine waveform corresponding to the phase is read by using the phase information corresponding to each harmonic order output from the address as an address. The multiplier 42 multiplies the amplitude value read from the sine function table 41 by the corresponding harmonic coefficient Hq. The amplitude accumulator 43 accumulates the amplitude values corresponding to the first harmonic, that is, the fundamental wave to, for example, the 32nd harmonic, thereby sequentially outputting the tone waveform amplitude value data.

FIG. 4 is a block diagram showing the configurations of the selected address generator 20 and the harmonic coefficient calculator 21. P
The EG 50 is a circuit that generates a pulse when the input signal rises, that is, when the key is turned on, and the pulse clears the counter H56. The EG 51 generates a pulse when the input signal rises and falls, that is, when the key is turned on and when the key is turned off. With this pulse, the counter L55
Is cleared, and the flip-flop (FF) 52 is set. When the FF 52 is set, its output Q becomes 1 and is supplied to one of the inputs of the AND gates 53 and 60.
5 is output.

On the other hand, the counter H56 is cleared when the key is turned on. The output of the counter H56 is stored in the sequence memory 5
7 is input to the lower address. Further, tone color information TC is connected to an upper address of the sequence memory 57. Note that, in addition to the timbre information, the timbre, the touch information, and the like may be input, and the timbre may be changed based on the information. FIG. 6A shows that in the sequence memory 57, 1
FIG. 9 is an explanatory diagram showing a format of sequence data stored corresponding to two pieces of timbre information. According to a lapse of time from the start to the end of generation of a musical tone, a musical tone is synthesized using any harmonic coefficient set. It stores information on whether to proceed. In fact, such data sets exist as many as the number of tone color information. The target D and source S columns respectively contain a harmonic coefficient set memory 61.
Are stored in the address information (S1, S2...) Indicating the harmonic coefficient set stored in the CON.
The number of times of repeated reading of the harmonic coefficient set is stored.

The value of CON is input to the comparator 58 and compared with the value of the counter L55. When they match, the output of the comparator 58 becomes 1. This signal is input to the clock terminal of the counter H56 via the AND gate 60, and increments the counter H while clearing the counter L55 via the OR gate 54. When CON is 0, control is performed so as to maintain that state until key-off. The NOR gate 59 outputs 1 when the value of CON is 0.
, And the FF 52 is reset. FF52 output is 0
Then, the counters H,
Since the input signal of L is cut off, the selected address generating section 20 holds the state until the key-off occurs. That is, during this time, the output of the counter H56 does not change, so that the same control information DA,
SA is output. As a result, the same harmonic coefficient set is fixedly read from the harmonic coefficient set memory 61.

The harmonic coefficient calculator 21 performs an interpolation operation for gradually shifting from the source harmonic coefficient set to the target harmonic coefficient set over the number of times specified by CON. The selector 70 switches between the source address SA and the target address DA output from the sequence memory 57 to change the harmonic coefficient set memory 6.
Feed to 1. The harmonic coefficient set memory 61 stores a plurality of harmonic coefficient sets for each tone color, and has a format as shown in FIG. 7A, for example. The figure shows an example in which one harmonic coefficient set is composed of 32 harmonic coefficients. Latches 62 and 63 latch the target harmonic coefficient and the source harmonic coefficient, respectively. Multiplier 64 multiplies the target harmonic coefficient by the output of converter 69, and multiplier 65 multiplies the source harmonic coefficient by the output of complementer 67. The adder 66 adds the outputs of the multipliers 64 and 65 and stores the interpolated harmonic coefficient in the harmonic memory 22.
Output to

The divider 68 converts the output value of the counter L to CON.
Divide by the value of. When CON is 0, 0 is output. The converter 69 is a converter using, for example, a ROM for changing the characteristics of the interpolation. By changing the conversion characteristics according to the timbre, the tone range, or the like, a delicate timbre change is possible. Note that this converter may be omitted. Complement 6
7 performs an operation such that y = (1−x), where the output value from the converter is x (0 ≦ x <1) and the output of the interpolator is y. That is, x is converted into a two's complement notation to obtain -x, and 1 is added to the value.

FIG. 10 is a waveform diagram showing an example of changes in the waveforms and data of the main part when the selected address generator 20 operates. When key-on occurs, both counters H and L are cleared, and FF 52 is set. Then, the counter L is incremented by the clock X, and a pulse is generated at the output of the AND 60 at the moment when the value becomes equal to the value of CON, the counter H is incremented, and the counter L is cleared by the output of the comparator 58. When the counter H steps up to k, 0 is output to CON (see FIG. 6A), so that the FF 52 is reset and the counter H56 stops stepping. As a result, fixed data is read from the sequence memory 57 and the harmonic coefficient set memory 61. When the key-off occurs, the FF 52 is set again by the output pulse of the EG, and the counter H is restarted. The divider 68 outputs a value as shown at the bottom of the figure, and performs an interpolation operation.

FIG. 11 is a waveform diagram showing a waveform of a main part of the harmonic coefficient calculator 21. In the first half of the basic operation unit (for example, 1 microsecond), the target address DA and the source address S output from the sequence memory 57
A is sequentially output from the selector 70. From the harmonic coefficient set memory 61, first, the target harmonic coefficient DH and then the source harmonic coefficient SH are sequentially read based on DA, SA, and harmonic order information Wq.
63, respectively. Assuming that the output of the converter 69 (divider 68) is 1/5, the value of (1-1 / 5) = 4/5 is output from the complementer 67. In the multiplier 64, the target harmonic coefficient DH
Is multiplied by 1/5, and the multiplier 65 multiplies the source harmonic coefficient SH by 4/5. The outputs of both multipliers are added by the adder 66, and the interpolated harmonic coefficient Hq is output.

In the harmonic coefficient calculation unit 21, when the basic operation unit is repeated by the harmonic order (for example, 32), 1
The two harmonic coefficient sets are stored in the harmonic memory 22,
When this is repeated for the musical tone generation channel (for example, 32), one harmonic order update cycle (accordingly, the waveform memory 26
(This is also the musical tone waveform update cycle). Clock X
Can be input at each update cycle in the shortest case, but since the update cycle of the waveform required to realize the tone color change of the musical tone waveform is generally longer, the clock X is equal to n of the update cycle of the waveform. The cycle is set to a multiple (n is an integer of 2 or more). Therefore, during the clock X, the calculation and update of the same data are repeatedly performed. As described above, according to the electronic musical instrument of the present invention, a musical tone waveform whose timbre changes with time can be obtained with a very small amount of data as compared with the waveform storage method and without using a circuit such as an envelope generator. It is possible to obtain. Further, the step of the counter H is temporarily stopped under the condition of CON = 0, and the step is restarted in response to the key-off, so that the continuous tone without timbre change during the scheduled time before the key-off. Is also easily generated.

Next, another embodiment will be described. FIG.
FIG. 9 is a block diagram showing a second embodiment of the selected address generator 20. The difference from the first embodiment shown in FIG. 4 is that RTN information as shown in FIG. 6B is added to the sequence memory 57, and when this information is 1, CN
The ON output value is loaded into the counter H, that is, jumping is performed. For this, the counter H
The RTN output of the sequence memory 57 is connected to the load terminal LD, and the preset input terminal of the counter H56 is connected to CON. When the sequence memory 57 in which information as shown in FIG. 6B is set is used,
Immediately after the value of the counter H becomes n, RTN becomes 1 and CO
The value of N becomes k. Therefore, k is loaded into the counter H, and the data at the address k is output. The NOR gate 59 detects that both CON and RTN are 0, and resets the FF 52. Therefore, as in the first embodiment, the counter H stops incrementing at the point where CON and RTN are 0, and It is possible to generate a sound.

FIG. 8B is a block diagram showing a main part of a third embodiment of the selected address generator 20. The difference from the first embodiment shown in FIG. 4 is that only one target harmonic coefficient set address is stored in one address of the sequence memory 57 as shown in FIG. At the time of reading, the coefficient is sequentially read from two consecutive addresses by using an address plus one adder. Counter H56
Is input to a +1 adder, and the next address is calculated. The selector 73 sequentially outputs the value of the counter H and the output value of the +1 adder to the sequence memory 57 as addresses, and the latches 74 and 75 latch DA and SA at timings corresponding to the respective addresses. The other operations are the same as those of the first embodiment. For example, it is possible to stop the stepping of the counter H at a position where CON is 0 and generate a continuous sound.

FIG. 9 is a block diagram showing an example in which the present invention is used for giving a temporal change of a formant coefficient. FIG.
Are provided in place of the harmonic coefficient calculation unit 21 in FIG. 4, and as shown in FIG. 7B, a formant coefficient set memory 8 storing a plurality of formant coefficient sets.
7, the harmonic coefficient Hq or the formant coefficient F
Output q. The HNo → KNo conversion memory 80 converts the harmonic order (first order, second order...) Into the key number interval (0, 12,...) (KNo = 12 Log2 q).
The bias generator 82 generates a predetermined bias value according to the strength of the touch signal. The adders 81 and 83 add the outputs of the conversion memory 80 and the bias generator 82 to the key number KNo.

The integer part In of the output of the adder 83 is input to the +1 adder 84, and (In + 1)
Is output. Address signals of the formant coefficient memory 87 are output from the selectors 85 and 86, respectively, and the combination order of the output signals is (In, DA).
(In, SA), (In + 1, DA), (In + 1, S
A). The latches 88 and 89, the multipliers 90 and 91, the adder 92, and the complementer 93 perform the same functions and operations as those of the first embodiment shown in FIG. Also has a converter). And the integers In and (I
(n + 1) are sequentially output. The interpolator 94 is an interpolation operation circuit having a configuration similar to that of the block surrounded by a dotted line in FIG. 9, and performs an interpolation operation based on the decimal part fr of the key number.

As described above, the information output from the interpolator 94 may be written to the harmonic memory 22 as the harmonic coefficient Hq, but a circuit for generating a harmonic coefficient corresponding to the timbre information is separately provided. The output of the circuit and the interpolator 9
4 may be multiplied by the information Fq output from 4 to obtain the harmonic coefficient Hq.

Although the embodiment has been described above, the following modifications are also conceivable. The sequence memory may be configured by a RAM, and the CPU may write the sequence information based on parameters such as tone color. The jump function is not limited to a simple jump, and a conditional jump function such as a jump only at key-off or a jump function capable of designating the number of jumps can be implemented.

[0026]

As described above, according to the electronic musical instrument of the present invention, the harmonic coefficient is switched at predetermined time intervals to generate a musical tone signal. That is, it becomes easy to arbitrarily change the timbre of the generated musical tone over time. That is, the timbre of a tone generated in response to one key depression is slightly changed (to match a natural musical instrument or according to preference) with the passage of time from the start of sounding, and before the sound is stopped. A continuous sound can be generated during the scheduled time.
In addition, in the place where the same harmonic coefficient is maintained, the same harmonic coefficient set is repeatedly read,
An increase in the data amount of the harmonic coefficient set is suppressed. Furthermore, if a specific harmonic coefficient group is repeatedly read by adding a jump function, a sustained tone can be generated with a small amount of data. Further, the present invention can be applied to formant coefficients instead of harmonic coefficients.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a tone generator 6 according to the present invention.

FIG. 2 is a block diagram showing a configuration of an electronic musical instrument to which the present invention is applied.

FIG. 3 is a block diagram illustrating a configuration of a waveform calculator 25 in FIG. 1;

FIG. 4 is a block diagram showing a configuration of a selected address generator 20 and a harmonic coefficient calculator 21.

FIG. 5 is a block diagram showing a second embodiment of the selected address generator 20;

FIG. 6 is an explanatory diagram showing a storage format of a sequence memory.

FIG. 7 is an explanatory diagram showing storage formats of a harmonic coefficient set memory and a formant coefficient set memory.

FIG. 8 is a block diagram showing a third embodiment of the selected address generator 20;

FIG. 9 is a block diagram showing an example in which the present invention is used for giving a temporal change of a formant coefficient.

FIG. 10 is a waveform chart showing an example of changes in waveforms and data of a main part when the selected address generation unit 20 operates.

11 is a waveform chart showing a waveform of a main part of the harmonic coefficient calculation unit 21. FIG.

[Explanation of symbols]

1 CPU, 2 ROM, 3 RAM, 4 panel part,
5 keyboard part, 6 tone generator, 7 D / A converter, 8 analog signal processor, 9 amplifier, 10 speaker, 11 bus

Claims (2)

(57) [Claims] 1. An electronic musical instrument for synthesizing a musical tone based on harmonic coefficient set information different for each tone color, a control means for generating key information and tone color information, and from a start to an end of one tone signal. Harmonic coefficient set storage means for storing a plurality of harmonic coefficient sets corresponding to at least a part of a musical tone waveform; and harmonics to be sequentially read from the harmonic coefficient set storage means in correspondence with a timbre corresponding to the timbre information. Sequence storage means for storing designation information for designating a wave coefficient set and the number of repetitions of reading of each harmonic coefficient set; and based on the designation information read from the sequence storage means in response to the key information and timbre information. After the specified harmonic coefficient set has been read out from the sequence storage means by the number of times of reading repetition read out, the next As set harmonic coefficients are read, and the read address generating means for designating a read address of said sequence storage means, especially for changing the interpolation characteristic in accordance with the tone color or tone range
Means comprising a sex conversion means, wherein the harmonic coefficient set information read out as described above and the number of repetitions
Based on the information, gradually change the harmonic coefficient information
An electronic musical instrument comprising: an interpolating unit for performing an interpolation operation for generating a tone signal based on harmonic coefficient set information output from the interpolating unit . 2. An electronic musical instrument for synthesizing a musical tone based on harmonic coefficient set information different for each timbre, comprising: control means for generating key information and timbre information; Harmonic coefficient set storage means for storing a plurality of harmonic coefficient sets corresponding to at least a part of a musical tone waveform, designation information for specifying a harmonic coefficient set to be sequentially read from the harmonic coefficient set storage means, and each harmonic Sequence storage means for storing a coefficient set readout repetition count; and a harmonic coefficient set to be read from the harmonic coefficient set storage means based on the designation information read out from the sequence storage means and the readout repetition count. And a selected address generator for sequentially specifying the read number of times of repetition, and a read harmonic. Based on several sets of information, and a musical tone signal generating means for generating a musical tone signal, repeatedly read is stored in the sequence storage means
To specify the harmonic coefficient set fixedly
In response to the generation of the key information, the selected address generation unit determines in advance from the harmonic coefficient set corresponding to the start of the tone signal during the scheduled time from the start of the tone generation in response to the generation of the ON signal of the key information. The same harmonic coefficient set is designated in a fixed manner until the off signal of the key information is generated after the scheduled time elapses, and the same harmonic coefficient set is further designated. An electronic musical instrument characterized by sequentially designating a predetermined harmonic coefficient set in response to an off signal.