JPH0318199B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a musical tone signal forming device, and particularly to an improvement of a musical tone signal forming device that forms musical tones using a frequency modulation method, and is suitable for use in electronic musical instruments. [Prior Art] Conventionally, modulation index information I, carrier frequency information ω _c t in the audible frequency range, and modulation frequency information ω _n t are provided, and based on these information, the instantaneous amplitude value e of a frequency modulated signal is determined. (t) is calculated based on the formula shown as e(t)=sin [ω _c t + Isinω _n t] ...(1), and this instantaneous amplitude value e
A frequency modulation type musical tone signal forming apparatus using (t) as a musical tone signal is known (Japanese Unexamined Patent Publication No. 126406/1983). By the way, in musical instruments such as pipe organs, the overtone composition of the generated musical tones differs between the high and low ranges, resulting in musical tones with different tones. [Problems to be Solved by the Invention] However, in the above-mentioned musical tone signal forming device, the ratio between the carrier frequency and the modulation frequency (hereinafter referred to as frequency modulation ratio) ω _c :ω _n is set only in accordance with the type of timbre. As a result, the harmonic composition does not change in the high and low ranges of musical tones, and it is not easy to generate a natural musical tone signal with different harmonic compositions in the high and low ranges, such as in a pipe organ. It had the following drawback. The present invention was made in view of these drawbacks, and its purpose is to enable a frequency modulation type musical tone signal forming device to form musical tone signals having different overtone compositions depending on the range of the musical tone signal to be formed. It is an object of the present invention to provide a musical tone signal forming device that provides a musical tone signal. [Means for Solving the Problems] For this purpose, the present invention is designed to change the frequency modulation ratio ω _c :ω _n according to the range of the musical tone signal to be formed. [Operation] Musical tone signals having different overtone compositions can be freely generated depending on the range of the musical tone signal to be formed. [Example] Hereinafter, the present invention will be described in detail based on the illustrated example. The figure is a block diagram showing an electronic musical instrument equipped with an embodiment of the musical tone signal forming device according to the present invention.
Broadly speaking, it consists of a keyboard section 1, a key press detection circuit 2, a frequency number memory 3, a frequency modulation circuit 4, a tone setting device 5, an amplitude control circuit 6, a DA converter 7, and a sound system 8. In the figure, when a certain key is pressed on the keyboard section 1, the pressed key detection circuit 2 detects this pressed key and outputs a key code KC corresponding to the pressed key, and also detects when any key is pressed. A key-on signal KON is output to indicate that the In this case, the key code KC is composed of an octave code OC indicating the octave range of the pressed key and a note code NC indicating the note name. This key code KC is then supplied to the frequency number memory 3 as an address signal for reading out the frequency number (numeric data) corresponding to the pressed key, and is also supplied to the frequency modulation circuit 4 and amplitude control circuit 6. It is supplied as address information for generating modulation ratio control information K1, K2 and amplitude information A(t) corresponding to the range of the pressed key. The frequency number memory 3 stores a frequency number F corresponding to the pitch of each key of the keyboard section 1 at each address. Therefore, this frequency number memory 3
When the key code KC corresponding to the pressed key is input as an address signal from the pressed key detection circuit 2, it outputs a frequency number F corresponding to the pitch of the pressed key. This frequency number F is supplied to multipliers 40 and 41 in frequency modulation circuit 4. The multiplier 40 is provided to change the frequency number F, which is the basis for creating the modulation frequency information ω _n t, according to the tone color and the range of the pressed key.
One of the multiplication inputs is a modulation ratio control information generator 4.
Modulation ratio control information K1 is input from memory 420 of No. 2. The multiplier 41 is provided to change the frequency number F, which is the basis for creating the carrier frequency information ω _c t, according to the timbre and the range of the pressed key.
One of the multiplication inputs is a modulation ratio control information generator 4.
Modulation ratio control information K2 is input from the memory 421 of No.2. Here, the modulation ratio control information K1, K2 is stored in the memory 420 as numerical information that corresponds to the tone set in the tone color setting device 5 and corresponds to the range of the pressed key.
421, respectively. That is, the memory 420 has a number of memory blocks corresponding to the types of selectable tones, and each memory block has memory addresses corresponding to the number of octave ranges of the keyboard section 1. corresponds to the tone of the memory block,
and modulation ratio control information K corresponding to the octave range.
I remember 1. Furthermore, the memory 421 is similarly configured, and stores modulation ratio control information K2 corresponding to the tone color and octave range in each memory address. Therefore, these memories 420, 421
On the other hand, when the tone setting information and the key code KC are supplied from the tone setting device 5 as an address signal, each memory 420, 421 outputs modulation ratio control corresponding to the set tone and corresponding to the tonal range of the pressed key. Information K1 and K2 are respectively output. Therefore, in the multipliers 40 and 41, the frequency number F corresponding to the pitch of the pressed key is multiplied by the modulation ratio control information K1, K2, respectively, so that the tone is changed according to the set tone and the pitch range of the pressed key. The frequency numbers K1.F and K2.F are output, respectively. The frequency number K1 changed in this way
F, K2·F are supplied to accumulators 43 and 44, respectively. The accumulator 43 sequentially accumulates the frequency numbers K1·F supplied from the multiplier 40 according to the clock pulse φ of a predetermined period, and calculates the accumulated value q×K.
1・F (q=1, 2, ...) as modulation frequency information ω _n
The accumulator 44 sequentially accumulates the frequency number K2·F supplied from the multiplier 41 in accordance with the clock pulse φ of a predetermined period, and the accumulated value q×K2·F (q= 1,
2...) as carrier frequency information ω _c t (hereinafter ω _c will be referred to as a first frequency signal, and ω _n will be referred to as a second frequency signal). In this case, the frequency numbers K1・F and K2・F are changed according to the set tone and the octave range of the pressed key, so the accumulators 43 and 44 correspond to the pitch of the pressed key, and also correspond to the pitch of the pressed key. Modulation frequency information ω _n that varies depending on the range and set tone
t and carrier frequency information ω _c t are output. Note that ω _n and ω _c of the modulation frequency information ω _n t and the carrier frequency information ω _c t naturally indicate frequencies within the audible frequency range. The modulation frequency information ω _n t outputted from the accumulator 43 is supplied to the sine function memory 45 as an address signal, and the carrier frequency information ω _c t outputted from the accumulator 44 is supplied to the adder 47 . The sine function memory 45 stores a sine amplitude value at each sample point phase of one period of the sine waveform at each address.
I remember sinωt. Therefore, when the modulation frequency information ω _n t is supplied as an address signal, the instantaneous amplitude value sin _{ω n} t of the modulation signal corresponding to the repetition frequency of the information ω _n t is output. This modulation signal
sinω _n t is supplied to a multiplier 46 . The multiplier 46 multiplies the modulation signal sinω _n t by the modulation index information I(t). Here, the modulation index information I(t) corresponding to the set timbre and the range of the pressed key is is provided by an index generator 48. That is, the modulation index generator 48 is supplied with information representing the set tone from the tone setting device 5 and a key code KC representing the pressed key from the key press detection circuit 2 as an address signal, and also receives the key-on signal KON.
When supplied, modulation index information I(t) with time-varying characteristics corresponding to the tone range of the pressed key and the set timbre is output in synchronization with the rise of the key-on signal KON.
As a result, the multiplier 46 outputs the modulated signal I(t) and the time-varying modulation index information I(t).
sinω _n t is output. This modulation signal I(t)・
sinω _n t is supplied to an adder 47 . The adder 47 modulates the carrier frequency information ω _c t by the modulation signal I(t)·sinω _n t and outputs the modulated signal, and the information ω _c t and the signal I(t)·sin ω _n t are When input, these are added and the added value is output as modulated frequency information [ω _c t+I(t)·sinω _n t]. This modulated frequency information [ω _c t+I
(t)·sinω _n t] is supplied to the sine function memory 49 as an address signal. Like the sine function memory 45 described above, the sine function memory 49 stores the sine amplitude sinωt at each sample point phase of one period of the sine waveform at each address. Therefore, when the modulated frequency information [ω _c t + I (t) · sin ω _n t] is supplied to the sine function memory 49 as an address signal, this sine function memory 49
outputs a frequency modulated signal e ₀ (t) expressed as e ₀ (t)=sin [ω _c t+I(t)·sin ω _n t].
That is, a signal in which a first frequency signal (sinω _c t) in the audible frequency range is frequency-modulated by a second frequency signal (sinω _n t) also in the audible frequency range.
e ₀ (t) is obtained. Frequency modulated signal e ₀ obtained as above
(t) is supplied to the amplitude control circuit 6 to control the setting of the amplitude value. That is, the frequency modulated signal e ₀ (t) is supplied to the multiplier 60, where it is multiplied by the amplitude setting information A(t) supplied from the amplitude information generator 61. In this case, the amplitude setting information A(t) is generated from the generator 61 in synchronization with the rise of the key-on signal KON, and has time-varying characteristics corresponding to the set tone and the range of the pressed key. Therefore, the frequency modulated signal e ₀ (t) is
The amplitude value is set by the amplitude setting information A(t) of the time-varying characteristic corresponding to the set tone color and the range of the pressed key. Frequency modulated signal whose amplitude setting is controlled in this way e(t)=A(t)・sin[ω _c t+I(t)・sinω _n
t] is converted into an analog signal by the DA converter 7 and supplied to the sound system 8, where it is produced as a musical tone. Here, the frequency number K is the basis for creating the modulation frequency information ω _n t and the carrier frequency information ω _c t.
1・F, K2・F are modulation ratio control information K1, K2
This is changed according to the range of the pressed key. For example, if the modulation ratio control information K1 and K2 are set as shown in Table 1 below for a certain tone in each octave range from pitch _C2 to _C7 , the information ω _c t and ω _n t The ratio is 1:6, 1:5, 1:4, corresponding to the ratio of information K2 and K1.
...and so on, depending on the range of the pressed key.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to freely form musical tone signals having different overtone compositions depending on the range of the musical tone signal to be formed.
In addition, since the frequency ratio of the first and second frequency signals is controlled based on both the basic timbre and the tone range, it is only necessary to control common parameters, which simplifies the configuration and makes the control easier. Since it is easy to perform, it is possible to obtain natural musical tones that are extremely similar to the musical tones generated by musical instruments such as pipe organs.

[Brief explanation of the drawing]

The figure is a block diagram showing an electronic musical instrument equipped with an embodiment of the musical tone signal forming device according to the present invention. 1...Keyboard section, 4...Frequency modulation circuit, 6...
Amplitude control circuit, 42...Modulation ratio control information generator.

Claims (1)

[Scope of Claims] 1. Pitch specifying means for specifying the pitch of a musical tone signal to be formed; timbre specifying means for specifying the basic timbre of the musical tone signal to be formed; a frequency signal generating means for generating first and second frequency signals in the audible frequency range corresponding to the pitch of the pitch; a modulating means for frequency modulating the first frequency signal in accordance with a second frequency signal; The frequency ratio of the first and second frequency signals is set with respect to the basic tone specified by the tone color specifying means, and is variable in accordance with the range to which the pitch specified by the pitch specifying means belongs. What is claimed is: 1. A musical tone signal forming apparatus, comprising: a control means for controlling the musical tone signal, and a musical tone signal is obtained based on the modulated output of the modulating means.