JP2529282B2 - Electronic musical instrument - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument capable of obtaining a musical tone waveform by a plurality of sound generation channels.

2. Description of the Related Art In recent years, digital technology has come to be used for electronic musical instruments, and in particular, it has become mainstream to synthesize musical tone waveforms of various tones using a plurality of sound generation channels.

Hereinafter, a conventional electronic musical instrument will be described with reference to the drawings.

 FIG. 3 shows the structure of a conventional electronic musical instrument.

In FIG. 3, 1 is a frequency instructing section for outputting data relating to frequency information, 2 is a sounding channel, 3 and 4 are respectively a first waveform synthesizing section, a second waveform synthesizing section, and 5 is an adder.

The operation of the conventional electronic musical instrument configured as described above will be described below.

The frequency instructing unit 1 connected to the plurality of waveform synthesizing units sends data regarding frequency information such as pitch bend or portamento to the first waveform synthesizing unit 3 and the second waveform synthesizing unit 4. Next, the first waveform synthesizing unit 3 and the second waveform synthesizing unit 4 synthesize the waveforms at frequencies based on the transmitted data regarding the frequency information, and the results are respectively synthesized into the first synthetic waveform and the second synthetic waveform. Output as a composite waveform.
Further, the adder 5 adds the respective synthetic waveforms to obtain a musical tone waveform.

By repeating the above operation, a tone waveform as shown in FIG. 4 can be obtained. Here, the data relating to the frequency information output from the frequency instructing unit 1 is output in synchronization with a relatively slow clock, and the frequency instructing unit 1 uses the first waveform synthesizing unit 3 and the second waveform synthesizing unit in the first clock. Data regarding frequency information is output to the waveform synthesizer 4 at intervals of A and B, respectively, and at intervals of C and D at the second clock.

The interval between the first clock and the second clock is about 5 to 10 msec.

Problems to be Solved by the Invention However, as is apparent from FIG. 4, the data on the frequency transmitted in synchronization with the clock is transmitted with a time difference such as A, B or C, D. There is a problem that the phases of the synthesized waveforms output from the first and second waveform synthesis sections are deviated, and the desired tone waveform cannot be obtained.

In view of the above problems, the present invention provides an electronic musical instrument capable of performing frequency control with a simple configuration without causing a phase shift between sounding channels.

Means for Solving the Problems To achieve this object, the electronic musical instrument of the present invention has a plurality of waveform synthesizing units for synthesizing musical tone waveforms in synchronization with a clock having a relatively high speed, It is composed of a frequency instructing unit that outputs data regarding frequency information to a plurality of waveform synthesizing units in synchronization with a slow clock, and a control flag for enabling or disabling data regarding frequency information.

According to the present invention, according to this configuration, the frequency instructing unit outputs the data related to the frequency information such as pitch bend or portamento to the plurality of waveform synthesizing units and outputs the control flag for invalidating or validating the data related to the frequency information to be output. Then, according to the control flag, the plurality of waveform synthesizing sections use or ignore the transmitted data regarding the frequency information to obtain a synthesized waveform.

With the above operation, the synthesized waveform output from each sound generation channel is synthesized by the frequency control according to the control flag.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an electronic musical instrument according to an embodiment of the present invention, and FIG. 2 is a synthetic waveform diagram for explaining the operation thereof.

In FIG. 1, 6 is a frequency instructing unit that outputs data relating to frequency information to a plurality of waveform synthesizing units 8 and 9 in synchronization with a clock having a slower speed than the waveform synthesizing unit described later, and 7 is valid data relating to frequency information Alternatively, 8 is a first waveform synthesizing unit, and 9 is a second waveform synthesizing unit, which synthesizes a musical tone waveform in synchronization with a clock having a predetermined constant speed.

The operation of the electronic musical instrument configured as described above will be described below.

First, when frequency control such as pitch bent or portamento is instructed, the frequency instructing unit 6 sets the control flag 7 to "1" in order to invalidate the data related to frequency information (Fig. 2E), and then frequency information. The data relating to the above is output to the first waveform synthesizing unit 8 and the second waveform synthesizing unit 9, respectively (FIG. 2, F, G). At this time point, each waveform synthesizer does not adopt the transmitted data regarding the new frequency information. After transmitting the data relating to the new frequency information to each waveform synthesizer, the frequency instructing unit 6 sets the control flag 7 to "0" in order to validate the transmitted data relating to the frequency information.

When the control flag becomes “0”, the first waveform synthesizing unit 8 and the second waveform synthesizing unit 9 immediately adopt the data relating to the new frequency information and start synthesizing the synthesized waveform of the frequency according to the data ( FIG. 2H).

Here, the first waveform synthesis section 8 and the second waveform synthesis section 9
Is synchronized with a clock having a relatively high speed of, for example, about 1 μsec, and the phase shift between the tone generation channels can be almost ignored.

The first synthesized waveform and the second synthesized waveform obtained by the respective waveform synthesis units are added by the adder 5, and the result is output as a musical tone waveform.

In this embodiment, the case where there are two sound generation channels has been described. However, in the case of three sound generation channels or more, frequency control can be performed for any channel by selecting the channel to which the control flag is applied. it can.

As described above, according to the present embodiment, since the new data relating to the frequency information is adopted according to the control flag for validating or invalidating, the frequency control of the musical tone waveform can be performed without causing the phase shift between the plurality of sound generation channels. A possible electronic musical instrument can be realized.

EFFECTS OF THE INVENTION Since the present invention disables the adoption of new data while outputting data relating to frequency information, the data is output to each waveform synthesis unit in synchronization with a clock relatively slower than the waveform synthesis unit. It is possible to prevent the time difference of the data relating to the generated frequency information, and thus to prevent the phase shift of the synthesized waveform between the sound generation channels.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic musical instrument according to an embodiment of the present invention, FIG. 2 is a synthetic waveform diagram obtained by the electronic musical instrument of the present embodiment, FIG. 3 is a block diagram of a conventional electronic musical instrument, and FIG.
The figure is a composite waveform diagram of a conventional electronic musical instrument. 1,6 …… Frequency indicator, 2 …… Sound channel, 4,9 ……
Second waveform synthesizer, 5 ... Adder, 7 ... Control flag,
3,8 ... First waveform synthesizer.

Claims (1)

(57) [Claims] 1. A plurality of waveform synthesizing units for synthesizing a musical tone waveform in synchronization with a clock having a predetermined constant speed, and data relating to frequency information in synchronization with a clock having a slower speed than the waveform synthesizing unit. A frequency instructing section for outputting to the waveform synthesizing section; and a control flag for validating or invalidating the data relating to the frequency information, wherein the waveform synthesizing section performs frequency control corresponding to the control flag. An electronic musical instrument.