JPH07234673A - Electronic musical instrument - Google Patents

Abstract

PURPOSE:To obtain the electronic musical instrument which is not electronic musical instrument which is not powered OFF unless a specific time is elapsed even if the power switch is turned OFF by providing a power supply means which continues to supply electric power for a specific time after the power switch is turned OFF. CONSTITUTION:A CPU 1 receives a timer interruption signal from a timer 2 at a previously set period and starts a timer interruption processing. It is checked whether or not a timer value for delay stored in a specific area of a RAM 3 is 0 and when the timer value is 0, the processing ends, but when not, one is subtracted from the timer value for delay and the result is stored in the specific area of the RAM 3 again. Consequently, even if a user turns OFF the power switch 15 by mistake, the power source 18 is not turned OFF unless the timer for delay reaches 0, and the power source 18 is held ON continuously without a momentary break by putting the power switch 15 back to the ON state. Consequently, the loss of data and the generation of a noise can be prevented.

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 controlling the power source of the electronic musical instrument.

[0002]

2. Description of the Related Art In a conventional electronic musical instrument, an ordinary mechanical switch is used as a power switch, and when the power switch is turned off, the power is immediately turned off.

[0003]

In the conventional electronic musical instrument as described above, for example, when the power switch is accidentally touched, the power is immediately turned off and the set tone color parameters and various setting data are lost. There was a problem that it would end up. In addition, if the power switch is accidentally touched while playing at a high volume and the power is turned off, not only the performance will be interrupted, but also a large amount of noise will be generated, possibly damaging the amplifier or PA (loudspeaker system) device. There were also problems.

An object of the present invention is to improve the problems of the prior art as described above, and to provide an electronic musical instrument in which the power cannot be turned off until a predetermined time elapses even when the power switch is turned off. To do.

[0005]

The present invention is characterized by comprising power supply means for continuously supplying power for a predetermined time after the power switch is turned off, and the power supply means is controlled by, for example, power supply control means. Thus, the switch means capable of turning the power on and off in parallel with the power switch, the means for detecting the off of the power switch, and the switch means being controlled to be on when the power is turned on, and the off of the power switch is detected. In some cases, the power supply control means controls the switch means to be turned off after a predetermined time.

[0006]

According to the present invention, even if the power switch is erroneously touched by the above means and the switch is turned off, the power is not turned off for a predetermined time. Therefore, it is possible to prevent data loss and noise generation.

[0007]

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 hardware configuration of an electronic musical instrument to which the present invention is applied. The CPU 1 controls the entire electronic musical instrument such as key assignment and sound generation control. The timer 2 generates an interrupt signal at an arbitrary cycle set by the CPU 1. The RAM 3 stores panel setting information such as tone color parameters, various control data in the musical instrument, or inputted automatic performance data. In ROM4,
Data such as control programs and envelopes are stored.

The keyboard 9 comprises a plurality of keys each having two switches, for example, and the keyboard scanning circuit 10 comprises a circuit for scanning a plurality of switches on the keyboard. The tone generator 11 is a circuit that reads out waveform information at an address interval corresponding to the pitch of the input performance information from a waveform memory in which waveforms are stored in advance, and generates a digital tone signal. The D / A converter 12 D / A converts the digital tone signal, and the amplifier 13 amplifies the tone signal to drive the speaker 14. The bus 17 connects each circuit in the electronic musical instrument.

The panel 7 is composed of operation switches, a volume and a display device such as a liquid crystal or LED, and the panel interface 8 is composed of a circuit for scanning the switch of the panel under the control of the CPU 1 and a drive circuit of the display device. The output of the power supply battery 18 is supplied to each circuit in the electronic musical instrument through a parallel circuit of the power switch 15 and the contact 16 of the power control relay 5. The power source is A
A C adapter or the like may be used. Power switch 15
The other contact of is connected to the panel interface 8 through the panel for detecting the state of the power switch, and the CPU 1 can read the state of the power switch 15 through the panel interface 8. The CPU 1 also uses the relay control circuit 6 to supply the power supply relay 5
To control. In addition to this, a MIDI interface circuit, a floppy disk interface circuit, a memory card interface circuit, etc. may be provided as necessary.

FIG. 3 is a flow chart showing the main processing of the CPU 1. When the power switch 15 of the electronic musical instrument is turned on, the CPU 1 controls the power relay 5 to be turned on via the relay control circuit 6 in step S10. In step S11, the power supply flag set in a predetermined area in RAM 3 is set to ON.
In step S12, initialization processing of the contents of the control information area in the RAM 3 and the contents of the control memory in the tone generator 11 is performed.

In step S13, the CPU 1 drives the keyboard scanning circuit 10 to scan the switches on the keyboard 9 and, when a change is detected, performs well-known event processing such as key-on and key-off processing according to the content of the change. . In step S14, the CPU 1 drives the panel interface 8 to scan the panel 7, and when detecting a change, performs an event process corresponding to the change content. In step S15, the CPU 1 performs a panel display process to display the current device status and the like. Step S16
In step 1, the CPU 1 sets the tone generation data for the tone generator 11 and updates the tone generation data. Steps S13 to S16 are general processing in a normal electronic musical instrument. In step S17, power supply control processing is performed. As will be described in detail later, this process controls the power supply relay 5 so that power is continuously supplied for a predetermined time even after the power switch is turned off.

FIG. 1 is a flow chart showing details of the power supply control process in step S17 of FIG. In step S20, it is checked whether or not the power switch is off. This processing is performed, for example, by the CPU 1 reading the state of the power switch 15 via the panel interface 8. If the determination result of step S20 is negative, the process proceeds to step S25, the power supply flag is set to ON and the process ends, but if the determination is affirmative, the process proceeds to step S21. In step S21, it is checked whether or not the power supply flag stored in the predetermined area of the RAM is on, and if it is on, the process proceeds to step S22.

In step S22, the power supply flag is set to OFF, and in step S23, RA is also set.
A predetermined value is set in the delay timer area set in the predetermined area of M. This predetermined value is determined, for example, by dividing the required delay time (for example, several seconds) by the timer interrupt period. In step S21,
If the power flag is off, the process proceeds to step S24. In step S24, it is checked whether the timer value is 0, and if it is not 0, the process ends, but 0
If it is, the power relay is turned off and the power is turned off.

FIG. 4 is a flow chart showing details of the timer interrupt processing. The CPU 1 receives the timer interrupt signal from the timer 2 at a preset cycle, and the timer interrupt process is activated. (Only the processing relevant to the present invention is shown in this flowchart.) In step S30, it is checked whether or not the delay timer value stored in the predetermined area of the RAM is 0, and if it is 0, it is determined. If it is not 0, the process proceeds to step S31. In step S31, the delay timer value is set to 1
Is subtracted and stored again in a predetermined area of the RAM.

By the above processing, even if the user accidentally turns off the power switch, the power is not turned off for a predetermined time until the delay timer reaches 0, and if the power switch is turned back on during that time, the power is turned off. Is supplied without interruption.

Although the embodiment has been described above, the following modifications are also possible. The user feels uneasy when the power supply is continued for too long, so the time is set to, for example, about several seconds, but this time may be arbitrarily set from the panel. If there is still a sounding channel even after the lapse of a predetermined time, the power is turned off after mute the sounding channel, and the switch is accidentally turned off. Even in this case, the sound is muted, so that a large amount of noise can be prevented.

Although an example in which a relay is used as the control means for the power supply is shown, it is also possible to use a current control element such as a transistor. Also, an example in which a switch having two circuits is used as the power switch is shown, but if a diode is used as shown in FIG. 5, for example, a switch of one circuit can be used. Although an example in which control is performed using a CPU is disclosed in the embodiment, for example, an integrating circuit including a capacitor and a resistor,
A timer circuit or a retriggerable one-shot multivibrator circuit can be used to generate a signal that maintains a high state for a predetermined time after the power switch is turned off, and the signal can be used to control a power control relay. is there.

[0018]

As described above, according to the electronic musical instrument of the present invention, even if the power switch is accidentally touched and the switch is turned off, the power cannot be turned off for a predetermined time.
If the power switch is turned back on during that time, it is possible to avoid power interruption, and it is possible to prevent data loss and noise generation.

[Brief description of drawings]

FIG. 1 is a flowchart showing details of power supply control processing.

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

FIG. 3 is a flowchart showing a main process of CPU 1.

FIG. 4 is a flowchart showing timer interrupt processing.

FIG. 5 is a circuit diagram showing another embodiment of the main part of the power supply circuit.

[Explanation of symbols]

1 ... CPU, 2 ... Timer, 3 ... RAM, 4 ... ROM, 5
… Power supply relay, 6… Relay control circuit, 7… Panel, 8
... Panel interface, 9 ... Keyboard, 10 ... Keyboard scan circuit, 11 ... Tone generator, 12 ... D / A converter, 13 ... Amplifier, 14 ... Speaker, 15 ... Power switch, 16 ... Power relay contact, 17 ... Bus , 18 ... Battery

Claims (3)

[Claims] 1. An electronic musical instrument comprising a power supply means for continuously supplying power for a predetermined time after the power switch is turned off. 2. The power supply means is turned on in parallel with the power switch under the control of the power supply control means.
A switch means that can be turned off, a means that detects the turning off of the power switch, and a switch means that when the power is turned on, the switch means is turned on, and if the power switch is turned off, the switch means is turned off after a predetermined time. The electronic musical instrument according to claim 1, further comprising: 3. The switch means is a relay circuit,
3. The electronic musical instrument according to claim 2, wherein the power supply control means is a storage program type control device having a built-in timer interrupt circuit capable of arbitrarily setting the predetermined time.