JPH10171447A - Key drive - Google Patents

Abstract

(57) Abstract: To provide a key driving device capable of driving a key while preventing generation of a mechanical collision sound. SOLUTION: In an activation section T1, a predetermined voltage is applied to a solenoid for driving a key, and the key is rotationally driven downward at high speed. In the activation section T2, the duty ratio t3: t
At 4, a voltage is applied to the solenoid, so that the key 12 is rotationally driven downward at a medium speed slower than the activation interval T <b> 1 within this movement interval T <b> 2. Further, the holding section T3
In, a voltage is applied to the solenoid at a duty ratio of t3: t4, whereby the key is driven to rotate downward at a lower speed even slower than the moving section T2. Therefore, no mechanical collision sound is generated when the key reaches the movement completion position, and no influence is exerted on the musical sound generated from the speaker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key driving device for driving keys of a keyboard instrument when performing an automatic performance.

[0002]

2. Description of the Related Art Conventionally, a so-called automatic piano which performs an automatic performance while driving each key of a keyboard has been known. This automatic piano is provided with an electromagnetic actuator for each key,
The electromagnetic actuator includes an iron core linked to a lower portion of each key, and a solenoid that is excited to drive the iron core in an axial direction. Then, a current is supplied to the electromagnetic actuator based on the key press information read from the memory, whereby the solenoid is excited to move the iron core backward, and the key is driven downward to generate sound. Also, the supply of current to the electromagnetic actuator is stopped based on the key release information, the solenoid is demagnetized to return the key, and the key is supplied by supplying current according to the key press information and stopping the current according to the key release information. The automatic performance is performed while driving.

[0003]

However, in such a key driving device employed in the conventional automatic piano, the operation of the electromagnetic actuator is controlled simply by turning on and off the current. Therefore, the solenoid of the electromagnetic actuator sucks the iron core from the initial position to the movement completion point with a constant suction force. Therefore, the iron core and the key reach the movement completion point at a high speed while the suction force of the solenoid is strong. The collision causes a mechanical collision sound, which affects the music to be played.

The present invention has been made in view of such a conventional problem, and has as its object to provide a key driving device capable of driving a key while preventing generation of a mechanical collision sound. Is what you do.

[0005]

According to the first aspect of the present invention, a key which is held in a substantially horizontal state and is rotatable downward and a drive signal are supplied. A drive unit that operates to drive the key downward; and a control unit that variably controls the drive signal to sequentially reduce the drive speed of the key by the drive unit. In such a configuration, the control unit variably controls the drive signal supplied to the drive unit, and sequentially reduces the drive speed of the key by the drive unit, so that the key can be driven to the movement completion position at high speed. Absent.

Further, in the invention described in claim 2, the driving means permits the key to return to the upward rotation after driving the key downward, and the control means further comprises the The drive unit is configured to variably control a drive signal when allowing the key to return to the upward rotation, thereby sequentially reducing the key return speed. Therefore, after the key is driven downward and reaches the movement completion position, the speed at which the key is returned to the substantially horizontal initial position also decreases, and the key which is urged to the substantially horizontal state moves to the initial position at high speed. The occurrence of a collision sound due to the arrival is also prevented.

According to the third aspect of the present invention, a key which is held in a substantially horizontal state and is rotatable downward, and a first key which is sequentially closed as the key is rotated downward. And a second contact point, a driving unit that is supplied with a drive signal and operates to drive the key downward, a section until the first contact point closes, and a section until the second contact point closes. Control means for supplying a drive signal with a different duty ratio between the sections and sequentially reducing the drive speed of the key by the drive means. In such a configuration, the control unit supplies a drive signal to the drive unit at a certain duty ratio in a section until the first contact is closed, and further supplies a drive signal to the drive unit in a section until the second contact is closed. Since the drive signal is supplied to the drive means at different duty ratios, thereby sequentially reducing the drive speed of the key, the key does not reach the movement completion position at a high speed.

Further, since the drive signals are supplied at different duty ratios by closing the respective contacts as described above, even if there is variation in the stroke amount of each key downward due to an assembly error. The key drive speed can be controlled by changing the duty ratio without being affected by the variation in the stroke amount. That is, for example, when the duty ratio is controlled to gradually decrease based on relative time information from the start of driving of the key, if the downward stroke amount of each key is smaller than a predetermined value due to an assembly error, the driving signal In a state where the duty ratio is large, the key reaches the movement completion position early. Therefore, when the key reaches the movement completion position, the key arrives at the movement completion position at high speed by the driving unit to which the drive signal having the large duty ratio is supplied, and a collision sound is generated. However, in the present invention, since the duty ratio is changed in the section where each contact is closed, even if each key has a variation in the stroke amount, the duty ratio is changed in each section without being affected by this. By changing the key, the speed when the key reaches the movement completion position is surely reduced.

Further, in the invention described in claim 4, the control means further supplies a drive signal with a different duty ratio in a section after the second contact is closed, and The drive speed of the key is reduced. Therefore, the moving speed of the key is controlled even immediately before the second contact point closes and the key reaches the movement completion position, whereby the generation of a collision sound when the key reaches the movement completion position is more reliable. Is prevented.

Further, in the invention according to claim 5, the driving means permits the key to return to the upward rotation after driving the key downward, and the control means further comprises: A drive signal is supplied at a different duty ratio between a section until the second contact is opened and a section until the first contact is opened with the return of rotation of the key upward, It is configured to gradually reduce the return speed. Therefore, after the key is driven downward and reaches the movement completion position, the speed at which the key is returned to the substantially horizontal initial position is also variably controlled. Collision noise caused by reaching the initial position is also prevented, and even if the upward stroke of each key varies due to an assembly error, it does not depend on the variation of the stroke. By changing the duty ratio, the key recovery speed can be reduced.

Further, in the invention according to claim 6, the control means further supplies a drive signal with a different duty ratio in a section after the first contact is opened, and controls the return speed of the key. It is configured to lower. Therefore, the moving speed of the key is controlled even immediately before the first contact is opened and the key reaches the initial position, whereby the key is moved.
The generation of a collision sound when the key reaches the initial position is also reliably prevented.

In addition, in the invention according to claim 7,
The control means is configured to convert the key speed information included in the sequentially read performance information into a duty ratio, and to supply the drive signal at the converted duty ratio. Therefore, the drive speed or the return speed of each key is variably controlled according to the key speed information included in the performance information.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an electronic musical instrument, and the electronic musical instrument has a keyboard 1 shown in FIG. The keyboard 1 is provided with a chassis 2, and a substantially horizontal base portion 3 is formed on the chassis 2, and an upper portion 4 is provided at one end of the base portion 3.
The upright part 5 is erected via the. Also, the base part 3
At the other end, a hanging portion 7 is vertically provided via a lower step portion 6, and a supporting portion 8 parallel to the base portion 3 is formed at a lower end of the hanging portion 7. A spring support felt 9 is provided on the step portion 4, an opening 10 is formed in the hanging portion 7, and a stopper felt 11 is provided on the support portion 8.

One end of a plurality of keys 12 is supported on the upper part of the upright portion 5 so as to be rotatable in the vertical direction.
A key spring 13 is elastically mounted between one end of the spring 2 and the spring supporting felt 9. A protruding piece 14 and a leg 15 are suspended from the other end of the key 12, and a hook 16 protruding into the opening 10 is formed at the lower end of the leg 15. As a result, the key 12 is maintained in a substantially parallel state by the hook portion 16 abutting against the upper edge of the opening 10 while being urged upward by the key spring 13.

On the lower surface of the key 12, a first projection 17a is formed on one end side.
The second protrusions 17b are arranged side by side on the other end side of the line a.
Immediately below these first and second projections 17a and 17b, a first contact 18a and a second contact 18b are arranged on the base portion 3. The first and second contacts 18a, 18b
Has a dome-shaped housing 21 made of rubber and a contact (not shown) arranged at an upper part in the housing 21, and the contact is mounted on the lower surface side of the base portion 3. It is configured to turn on when it comes into contact with a contact (not shown) provided on the printed circuit board 22. Therefore, when the key 12 rotates downward, the first contact 18a is turned on first, and the second contact 18
b is turned on with a time difference corresponding to the rotation speed of the key 12. When the key 12 is turned upward after both contacts 18a and 18b are turned on, the second contact 18b is turned off first and the first contact 18a is continuously turned to the turning speed of the key 12. It is configured to be turned off with a corresponding time difference.

A bracket 23 having standing walls 23a, 23b at both ends is attached to the lower surface of the base portion 3. A holder 24 having standing pieces 24a, 24b at both ends is mounted on the bracket 23. Fixed. In the holder 24, a solenoid 26 is disposed between the upright pieces 24a, 24b.
6, an iron core 25 is inserted so as to be movable in the axial direction.
The iron core 25 slidably penetrates the upright piece 24b and the upright wall 23b, and is configured to move backward when the solenoid 26 is excited. A flange 25a is formed in the middle of the iron core 25 so as to contact the upright wall 23b, and a return spring 28 is elastically mounted between the flange 25a and the one upright wall 23b. Biased in the direction.

A pivot member 29 is fixed on the lower step 6, and a bell crank 30 is rotatably supported on the pivot member 29. One end of the bell crank 30 is loosely fitted to the protruding piece 14 protruding from the lower surface of the key 12, and the other end is linked to a rod 31 protruding from the front end surface of the iron core 25. . Therefore, when the solenoid 26 is excited, the iron core 25 is retracted against the return spring 28, and accordingly, the bell crank 30 is driven to rotate clockwise by the rod 31. Then, the protruding piece 14 is pulled down by the bell crank 30, and the other end of the key 12 is rotated downward while the key spring 13 is contracted, and a key pressed state is formed. When the solenoid 26 is demagnetized, the iron core 25 and the rod 31 move forward under the urging force of the return spring 28, and the bell crank 30
Rotates counterclockwise. As a result, the key 12 can rotate upward, is pushed up by the urging force of the key spring 13, and returns to the initial position.

FIG. 2 is a block diagram showing a circuit configuration of the automatic piano according to the present embodiment. The operation panel 33 includes various operation switches such as a power switch, a tone designation switch, and an automatic performance start / stop switch. Is provided. The CPU 32 as control means includes an operation panel 3
The operation information of the switch from No. 3 and the rotation position information of each key 12 from the key position detecting device 34 are input. CPU3
2 operates based on the input information and the program stored in the ROM 35 while using the RAM 36 as a work area, and controls the solenoid driver 37 and the sound source 38. The waveform ROM 39 stores various waveforms such as a piano tone and an organ tone.
In accordance with an instruction from U32, a waveform of a preselected timbre is read from the waveform ROM 39 at a reading speed corresponding to the designated pitch, to generate a tone signal. The tone signal is converted into an analog signal by the D / A converter 40, and then amplified by the amplifier 41. The amplified tone signal drives the speaker 43 to emit sound. ing.

The key position detecting device 34 includes a first key position detecting device 34a and a second key position detecting device 34b as shown in FIG. Double key position detection device 3
4a and 34b are connected to the printed circuit board 22, and in the first key position detecting device 34a, the first contact 18
In the second key position detecting device 34b, the on / off state of the second contact 18b is detected and input to the CPU 32. Further, the solenoid driver 37 is provided in FIG.
As shown in (B), a current / voltage amplifying device 37a is applied, and a current of a predetermined voltage is applied to the solenoid 26 at a duty ratio as described later.

The ROM 35 stores automatic performance information together with programs. This automatic performance information includes time information indicating the time until the next information is read out,
It consists of key press information or key release information that is read out when the time indicated by the time information has elapsed. The time information and the key press information or key release information are stored alternately, and the automatic performance information of one piece of music is composed. Have been. The key press information is composed of pitch information and key velocity information at the time of key depression, and the key release information is composed of pitch information and key velocity information at the time of key release. Therefore, C
The PU 32 reads the key press information at the timing indicated by the time information, instructs the sound source 38 to sound at the pitch indicated by the pitch information,
Alternatively, by instructing the sound source 38 to mute the pitch indicated by the pitch information at the timing indicated by the time information, the automatic performance of the musical piece proceeds.

As shown in FIG. 4, the key velocity information at the time of key depression includes velocity information of a start section T1 from the timing at which the key depression information is read until the first contact 18a is turned on, and
The speed information of the moving section T2 from when the first contact 18a is turned on to when the second contact 18b is turned on, and the second contact 1
8b, the speed information of the holding section T3 after the switch 8b is turned on. This holding section T3 is a section until the corresponding key release information is read, as shown in FIG. As shown in FIG. 5, the key velocity information at the time of key release is the second contact point 18b from the timing at which the corresponding key release information is read.
The speed information of the release section T4 until the first contact 18b is turned off, the speed information of the braking section T5 until the first contact 18a is turned off after the second contact 18b is turned off, and the second contact 18b is turned off. The landing section T6 is a section until a predetermined time elapses after the first contact 18a is turned off.

Next, the operation of the present embodiment according to the above configuration will be described with reference to the flowchart of FIG. That is, when the automatic performance start switch provided on the operation panel 33 is operated, the CPU 32 starts operation in accordance with the flowchart shown in FIG. 4, and executes automatic performance processing such as time information processing (step A1). In the automatic performance processing such as time information processing, the automatic performance information is sequentially read from the ROM 35, and if the read information is the time information, it stands by during that time. If it is key release information, the sound source 38 is instructed to mute.
Therefore, the automatic performance is performed by performing the process of step A1, and the tone of the music to be automatically performed is generated from the speaker 42.

After performing the processing of step A1, it is determined whether there is key press information or key release information to be read next (step A2). If there is no key release information, the processing according to this flow is terminated. However, immediately after the start of the automatic performance, since there is naturally key-pressing information or key-release information to be read out, it is read out, and then it is determined whether or not the read-out information is key-pressing information (step A
3). If the result of this step A3 is key-depression information, the key-speed information contained in the key-depression information is converted into duty ratio information of the activation section T1 (step A3).
4). That is, in the example shown in FIG. 4, the key speed information of the activation section T1 is converted into the duty ratio 1: 0 of the activation section T1, and then the timer process (step A5) is executed.

This timer process is performed according to the flowchart shown in FIG. 7. After the converted duty ratio information is set in the timer (step B1), the timer port is turned "ON" (step B2). By the processing in step B2, the CPU 32 controls the solenoid driver 37 to apply a voltage in accordance with the duty ratio information until the first contact 18a is turned on. Therefore, in the case of the example shown in FIG. In the activation section T
In 1, the predetermined voltage is continuously applied. Therefore, in this activation section T1, the iron core 25 moves backward at high speed, and the key 12 is also driven to rotate downward at high speed.

The timer processing in step A5 is performed in the first
Until the key position is detected (step A6),
The operation is continued until the contact 18a is turned on, and the first projection 17a presses the first contact 18a with the downward rotation of the key 12, the first contact 18a is turned on, and the first key position detecting device is turned on. When the ON signal is output from the key pressing information 34a, the key speed information included in the key pressing information is converted into duty ratio information of the activation section T2 (step A7). That is, in the example shown in FIG. 4, the key speed information of the moving section T2 is converted into the duty ratio t1: t2 (4: 1) of the moving section T2, and then the timer processing (step S5) is performed in the same manner as in step A5 described above. Execute A8). By the processing in step A8, the CPU 32 controls the solenoid driver 37 to apply a voltage in accordance with the duty ratio information until the second contact 18b is turned on. Therefore, in the case of the example shown in FIG. In T2, the application of the voltage to the solenoid 26 for the time t1 and the stop of the application for the time t2 are repeated. Therefore, in this moving section T2, the iron core 25 moves backward at a middle speed lower than that of the starting section T1, and the key 1
2 is also driven to rotate downward at a medium speed.

The timer processing in step A8 is performed in the second
Until the key position is detected (step A9),
The operation is continued until the contact 18b is turned on, and the second projection 17b presses the second contact 18b with the downward rotation of the key 12, the second contact 18a is turned on, and the second key position detecting device 34b When the ON signal is output from the CPU, the key speed information included in the key press information is converted into the duty ratio information of the holding section T3 (step A10). That is, in the example shown in FIG. 4, the key speed information of the holding section T3 is
Is converted to the duty ratio t3: t4 (1: 1), and then a timer process (step A11) is executed in the same manner as in step A5 described above.

By the processing in step A11, the CPU
Reference numeral 32 denotes a solenoid driver for applying a voltage in accordance with the duty ratio information until key release information is read.
7, the application of the voltage to the solenoid 26 for the time t3 and the stop of the application for the time t4 are repeated in the holding section T3 in the example shown in FIG. For this reason,
In the holding section T2, the iron core 25 is
The key 12 moves backward at a lower speed than that of the key 2, and the key 12 is also rotated downward at a low speed. Therefore, when the iron core 25 collides with the position regulating member in the solenoid 26, or when the key 12
When the leg 15 collides with the stopper felt 11, no mechanical collision sound is generated, and no influence is exerted on the musical sound generated from the speaker 42.

When the contacts 18a and 18b are turned on, voltages are applied to the solenoids 26 at different duty ratios. Therefore, the downward stroke of each key 12 is caused by an assembly error. Even if there is a variation, the duty ratio is changed and each section T of the key 12 is changed without being influenced by the variation of the stroke amount.
The driving speed can be controlled at 1, T2, and T3. That is, for example, when the duty ratio is controlled to gradually decrease based on relative time information from the start of driving of the key 12, if the downward stroke amount of each key 12 is smaller than a predetermined value due to an assembly error, the duty The key 12 reaches the movement completion position in a state where the ratio is large. Therefore, when the key 12 reaches the movement completion position, the key 12 is driven by the solenoid 26 to which a voltage having a large duty ratio is supplied.
, The leg 15 collides with the stopper felt 11 at high speed, and a collision sound is generated. However, in this embodiment, each contact 18a, 1
Since the duty ratio is changed in the sections T1, T2, and T3 in which the switch 8b is turned on, even if there is a variation in the stroke amount of each key 12, the sections T1, T2, and T3 are surely not affected by the variation. , The duty ratio can be changed, and the speed of the key 12 when reaching the movement completion position can be reliably reduced. Therefore, even when the downward stroke amount of each key 12 varies due to an assembly error, it is possible to prevent the generation of a collision sound without being influenced by the variation.

On the other hand, if the key release information is read in the state where the timer processing of step A11 is being executed, when the processing according to the flow shown in FIG. 6 is repeatedly executed, the determination in step A3 is NO. Then, the process proceeds to step A12. Then, in step A12, the key speed information included in the key release information is converted into duty ratio information of the release section T4 (step A12). That is, in the example shown in FIG. 5, the key speed information of the release section T4 is converted into the duty ratio 0: 1 of the release section T4, and thereafter, the timer process (step A13) is executed in the same manner as step A5 described above. . By the process in step A13, the CPU 32 controls the solenoid driver 37 to apply a voltage in accordance with the duty ratio information until the second contact 18b is turned off, and in the case of the example shown in FIG. , The solenoid 26 is demagnetized. Therefore, in this release section T4, the iron core 25 moves forward at a high speed by the spring force of the return spring 28, and the key 12 also rotates upward and returns at a high speed.

The timer processing in step A13 is performed until the second key position is detected at the time of key release (step A13).
14) That is, the operation is continued until the second contact 18b is turned off (step A14), and the second projection 17b releases the pressing of the second contact 18b with the upward rotation of the key 12, and this second contact 18b is turned off and the second key position detecting device 34
When the off signal is output from b, the key speed information included in the key release information is converted into duty ratio information of the braking section T5 (step A15). That is, in the example shown in FIG. 5, the key speed information of the braking section T5 is converted into the duty ratio t5: t6 (1: 4) of the braking section T5, and then the timer processing (step S5) is performed in the same manner as the above-described step A5. A16) is executed. By the processing in step A16, the CPU 32 keeps turning on the second contact 18b until the second contact 18b is turned off.
The solenoid driver 37 is controlled to apply a voltage in accordance with the duty ratio information. Therefore, in the case of the example shown in FIG.
The voltage application for 5 hours and the application stop for t6 hours are repeated. Then, a braking force by the magnetic force of the solenoid 26 acts on the iron core 25 moving forward by the spring force of the return spring 28. For this reason, in this braking section T5, the iron core 25 moves forward at a middle speed slower than that of the release section T4, and the key 12 also rotates upward and returns at the middle speed.

The timer processing in step A16 is performed until the first key position is detected at the time of key release (step A16).
17) That is, the operation is continued until the first contact 18a is turned off, and the first protrusion 17a
Releases the pressing of the first contact 18a, and the first contact 18b
Is turned off to output an off signal from the first key position detecting device 34a, the key speed information included in the key release information is converted into duty ratio information of the landing section T6 (step A18). . That is, in the example shown in FIG. 5, the key speed information of the landing section T6 is changed to the duty ratio t of the landing section T6.
7: t8 (1: 2), and then a timer process (step A19) is performed in the same manner as step A5 described above. By the processing in step A19, the CPU 32
Controls the solenoid driver 37 to apply a voltage according to the duty ratio information until a predetermined time elapses. Therefore, in the case of the example shown in FIG. Voltage application and t8
The application of time is stopped. Then, the iron core 25 moving forward due to the spring force of the return spring 28.
In addition, the braking force by the magnetic force of the solenoid 26 acts more than the braking section T5. Therefore, this landing section T
In 6, the iron core 25 moves forward at a lower speed than the braking section T4, and the key 12 also rotates upward and returns at this low speed. Therefore, the iron core 25 moves forward to the initial position, and the flange 25 a
b, and when the key 12 returns to the initial position and the hook 16 contacts the upper edge of the opening 10, no mechanical collision sound is generated, and the sound is generated from the speaker 42. There is no effect on the musical sound.

When the contacts 18a and 18b are turned off, voltages are applied to the solenoids 26 at different duty ratios. Therefore, the upward stroke of each key 12 is caused by an assembly error. Even if there is a variation, the duty ratio is changed and each section T of the key 12 is changed without being influenced by the variation of the stroke amount.
At 4, T5 and T6, the return speed can be controlled. That is, for example, when the duty ratio is controlled to be gradually increased based on relative time information from the time when the key 12 is returned, the upward stroke amount of each key 12 due to an assembly error is smaller than the predetermined value. The key 12 reaches the initial position with the ratio being small. Therefore,
When the key 12 reaches the initial position, since a voltage with a small duty ratio is supplied to the solenoid 26, the key 12 cannot obtain a sufficient braking force, and
0 collides with the upper edge at high speed, and a collision sound is generated. However, in this embodiment, each contact 18
Since the duty ratio is changed in the sections T4, T5, and T6 in which the keys a and 18b are turned off, even if there is a variation in the stroke amount of each key 12, the sections T4 and T5 are surely not affected by the variation. , T6, the duty ratio can be changed, and the speed of the key 12 when reaching the initial position can be reliably reduced. Therefore, even when the downward stroke amount of each key 12 varies due to an assembly error, it is possible to prevent occurrence of a collision sound when returning, without being influenced by the variation.

If the timer processing in step A19 has been performed for a predetermined time, the timer port is set to "of".
f ”to end the timer process. Therefore, by repeating the flow shown in FIG.
The downward rotation speed and the upward return speed of the key 12 vary in accordance with the read key speed information, so that the player can play the key 12 in a form as if he or she were actually playing on the keyboard 1. Can be driven.

Although the present embodiment has been described with reference to the case where the present invention is applied to an electronic musical instrument, it is needless to say that the present invention can also be applied to an acoustic musical instrument.

[0035]

As described above, according to the present invention, the driving signal supplied to the driving means for driving the key downward is variably controlled so that the driving speed of the key by the driving means is sequentially reduced. Since the key is not driven to the movement completion position at high speed, the mechanical collision sound caused by the key reaching the movement completion position at high speed can be prevented, and the effect on the music to be played can be prevented. Can be eliminated. Further, since the drive means variably controls the drive signal when allowing the key to return to the upward rotation, the return speed of the key is gradually reduced, so that the key is moved to the initial position at high speed. It is possible to prevent the mechanical collision sound caused by the key reaching the initial position at high speed without the rotation returning.

Further, first and second contacts are provided which are sequentially closed in accordance with the downward rotation of the key, and a section until the first contact is closed and the second contact are closed. Since the drive signals are supplied at different duty ratios and the drive speed of the keys by the drive unit is sequentially reduced in the interval until the key stroke, variations in the downward stroke of each key due to assembly errors are caused. Even in some cases, the key drive speed can be controlled by changing the duty ratio without being affected by the variation in the stroke amount. Therefore, even when the downward stroke amount of each key varies due to the assembly error, it is possible to prevent the mechanical collision sound caused by the key reaching the movement completion position at high speed. it can. Further, in a section after the second contact is closed, a drive signal is supplied at a different duty ratio to reduce the drive speed of the key by the drive means, so that the key reaches the movement completion position. In this case, it is possible to more reliably prevent the collision sound from being generated.

In addition, a drive signal is supplied at a different duty ratio between a section until the second contact is opened and a section until the first contact is opened with the return of the key to the upward rotation. Since the return speed of the keys is sequentially reduced, even if there is variation in the upward stroke amount of each key due to an assembly error, the duty can be reduced without being affected by the variation in the stroke amount. By changing the ratio and reducing the key return speed, it is possible to prevent the generation of a collision sound when the key reaches the initial position. Further, since the drive signal is supplied at a different duty ratio in a section after the first contact is opened to reduce the key return speed, a collision sound is generated when the key reaches the initial position. Can be more reliably prevented.

In addition, since the key speed information included in the performance information sequentially read is converted into a duty ratio and the drive signal is supplied at the converted duty ratio, each key is included in the performance information. The drive speed or the return speed can be variably controlled in accordance with the key speed information, and the keys can be driven as if they were actually playing.

[0039]

[Brief description of the drawings]

FIG. 1 is a side view of a keyboard of an electronic musical instrument according to an embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of the electronic musical instrument according to the embodiment.

FIG. 3A is a detailed block diagram of a key position detecting device,
(B) is a detailed block diagram of the solenoid driver.

FIG. 4 is a time chart showing a relationship between each section and a drive signal when a key is pressed.

FIG. 5 is a time chart showing a relationship between each section and a drive signal at the time of key release.

FIG. 6 is a flowchart illustrating a processing procedure of a CPU.

FIG. 7 is a flowchart illustrating a processing procedure of a timer process.

[Explanation of symbols]

 Reference Signs List 1 keyboard 12 key spring 18a first contact 18b second contact 25 iron core 26 solenoid 32 CPU 34 key position detecting device

Claims (7)

[Claims] 1. A key which is held in a substantially horizontal state and is rotatable downward, driving means which is supplied with a drive signal and operates to drive the key downward, and variably controls the drive signal. Control means for sequentially reducing the driving speed of the key by the driving means. 2. The driving unit allows the key to rotate upward after returning the key downward, and the control unit further controls the driving unit to rotate the key upward. By variably controlling the drive signal when allowing return,
2. The key driving device according to claim 1, wherein the return speed of the key is sequentially reduced. 3. A key which is held in a substantially horizontal state and is rotatable downward, first and second contact points which are sequentially closed as the key is rotated downward, and a drive signal is supplied. A driving unit that operates to drive the key downward, and that generates a drive signal with a different duty ratio in a section until the first contact is closed and in a section until the second contact is closed. Control means for supplying and sequentially decreasing the driving speed of the key by the driving means. 4. The control unit further supplies a drive signal with a different duty ratio in a section after the second contact point is closed, thereby reducing a drive speed of the key by the drive unit. The key driving device according to claim 3, wherein 5. The driving means permits the key to rotate upward after driving the key downward, and the control means further controls the key to rotate upward when the key returns upward. A drive signal is supplied at different duty ratios in a section until the second contact is opened and in a section until the first contact is opened, and the return speed of the key is sequentially reduced. The key driving device according to claim 3. 6. The key control device according to claim 5, wherein the control unit further supplies a drive signal with a different duty ratio in a section after the first contact is opened to reduce the key return speed. Key drive. 7. The control device according to claim 1, wherein the control means converts key speed information included in the sequentially read performance information into a duty ratio, and supplies the drive signal at the converted duty ratio. 7. The key driving device according to any one of items 1 to 6.