Electronic percussion instrument having a memory function and a musical tone parameter control function

During percussion performance, percussion data corresponding to states of percussion sequentially detected by percussion-detection section and tone pitch data corresponding to the sequentially struck percussion members are stored. The stored percussion data and tone pitch data are sequentially read out to generate musical tones, each having a tone pitch corresponding to the tone pitch data, in accordance with the percussion data. Parameters of musical tones to be generated or being generated are controlled in accordance with instructions of a parameter indication section provided on a striking member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an electronic percussion instrument used 
for playing a melody by percussion operation similar to that in playing an 
acoustic percussion instrument such as a zylophone, marimba and the like, 
and more particularly, to an electronic percussion instrument capable of 
storing and/or reproducing a melody performance state and a chord 
performance state in real time. 
2. Description of the Related Art 
With recent, rapid developments of electronic technology and digital 
technology, various types of electronic percussion instruments have been 
developed, which electronically generate particular musical tones in 
response to percussion operation. These electronic percussion instruments 
can be classified into five types of instruments, such as (A) an 
electronic percussion instrument of a drum type, (B) an electronic 
percussion instrument of a drum stick type, (C) an electronic percussion 
instrument of a guitar type, (D) an electronic percussion instrument of a 
step-on type and (E) an electronic percussion instrument of a sound plate 
type. 
Among the above mentioned electronic percussion instruments, any of the 
electronic percussion instrument of a drum type, the electronic percussion 
instrument of a drum stick type and the electronic percussion instrument 
of a guitar type is not capable of selectively generating a musical tone 
having a particular tone pitch in response to striking operation. 
Therefore, these instruments can not be used for playing melodies and 
chords. On the contrary, the above mentioned electronic percussion 
instrument of a step type and electronic percussion instrument of a sound 
plate type are capable of selectively generating a musical tone having a 
particular tone pitch in response to striking operation or stepping 
operation. Therefore, these instruments can be used for playing moldies 
and chords. 
The electronic percussion instrument of a drum type (A) is a musical 
instrument which has a drum, to the struck portion of which a vibration 
sensor is attached, and which generates relevent acoustic signals or 
musical tones on the basis of output signals output from the vibration 
sensor in response to striking operation. This type of electronic 
percussion instruments are disclosed in, for example, the following patent 
publications: 
(1) Japanese Utility Model Disclosure (Kokai) No. 58-16693 (disclosed on 
Feb. 1, 1983), inventor: Kunihiko Watanabe, applicant: Nippon Gakki Seizo 
Kabushiki Kaisha) 
(2) U.S. Pat. Nos. 4581972 and 4581973 (issued on Apr. 15, 1986, inventor: 
Yoshiki Hoshino, assignee: Hoshino Gakki) 
(3) U.S. Pat. No. 4418598 (issued on Dec. 6, 1983, inventor: Scott S. 
Klynas, assignee: Mattel, Inc.) 
(4) U.S. Pat. No. 4479412 (issued on Oct. 30, 1984, inventor Scott S. 
Klynas, assignee: Mattle, Inc.) 
(5) U.S. Pat. No. 4679479 (issued on July 14, 1987, inventor: Hisakazu 
Koyamato, assignee: Nippon Gakki Seizo Kabushiki Kaisha) 
(6) Japanese Utility Model Disclosure (Kokai) No. 60-76399 (disclosed on 
May 28, 1985, inventor: Eiichiro Aoki, applicant: Nippon Gakki Seizo 
Kabushiki Kaisha) 
Technology relating to the present invention is disclosed in U.S. Pat. No. 
4781097 (issued on Nov. 1, 1988, inventors: Shigeru Uchiyama et al., 
assignee: Casio Computer Co., Ltd. the same assignee of the present 
invention.) 
The above described electronic percussion instrument of a drum stick type 
(B) is an electronic musical instrument which outputs relevent acoustic 
signals or musical tone signals on the basis of output signals output from 
a stick shape striking member such as a drum stick and a mallet. This 
stick shape striking member is provided with a vibration sensor which 
generates output signals to be used for the above musical instrument in 
response to striking and/or swinging operation of the same. This type of 
the electronic musical instruments are disclosed in, for example, the 
following patent publication: 
(1) Japanese Utility Model Publication No. 59-5912 (published on Feb. 22, 
1984, inventor: Shouiti Momobe, applicant: Nippon Gakki Seizo Kabushiki 
Kaisha) 
(2) Japanese Pat. Disclosure (Kokai) No. 62-96996 (disclosed on May 6, 
1987, inventor: Yoshiyuki Murata, applicant: Casio Computer Co., Ltd.) 
(3) Japanese Utility Model disclosure (Kokai) No. 62-116300 (disclosed on 
July 23, 1987, inventor: Shinji Nagumo, applicant: Casio Computer Co., 
Ltd.) 
(4) U.K. Patent Application GB2183076A (disclosed on May 28, 1987, 
inventor: Ian Barry Tragen, applicant: Ian Barry Tragen.) 
This type of an electronic percussion instrument is disclosed in U.S. 
patent application Ser. No. 053384 (filed on May 22, 1987, inventors: 
Yukio Kashio et al, assigneee: Casio Computer Co., Ltd. the same assignee 
of the present application) 
The above mentioned electronic percussion instrument of a guitar type (C) 
is an electronic musical instrument of a guitar shape, which is provided 
with manual switches and is caused to generate musical tone signals having 
particular timbre in response to striking operation when the manual 
switches are struck. This type of electronic musical instruments are 
disclosed in, for example, the following patent publications: 
(1) Japanese Patent Disclosure (Kokai) No. 62-157092 (disclosed on July 13, 
1987, inventor: Sigeru Imura applicant: Sony Corp.) 
(2) PCT International Disclosure No. WO 86/01927 (disclosed on March 27, 
1986, inventor: Jones, Peter, Stephan, applicant: Dynacord Electronic Und 
Geratebau Gmbh & Co., Kg) 
The above electronic percussion instrument of a step-on type (D) is an 
electronic musical instrument which has a flexible mat within which is 
arranged a plurality of flexible switches in order of the tone scale and 
which is caused to generate musical tones each having a corresponding tone 
pitch when the flexible switches are stepped on. This type of electronic 
musical instruments are disclosed in, for example, U.S. Pat. No. 4121488 
(issued on Oct. 24, 1978, inventor: Kakunosuke Akiyama, assignee: Nep 
Company, Ltd.) 
The above-mentioned electronic percussion instrument of a sound plate type 
(E) is an electronic musical instrument which has a set of sound plates 
arranged in order of tone pitch and each provided with a pressure sensor 
and which is caused to generate musical tones each having a tone pitch 
corresponding to the struck sound plate when the sound plates are struck 
with a mallet. This type of electronic percussion instruments are 
disclosed in, for example, the following patent disclosure: 
(1) Japanese Patent Disclosure (Kokai) No. 61-239299 (disclosed on Oct. 24, 
1986, inventors: Akihiko Takeuchi et al, applicant: Nippon Gakki Seizo 
Kabushiki Kaisha.) 
(2) U.S. Pat. No. 3546353 (issued on Dec. 8, 1970, inventor: Georges Jenny, 
assignee: Societe a Responsabitte Limitee dite) 
(3) Japanese Utility Model Disclosure (Kokai) No. 59-94399 (disclosed on 
June 27, 1984, inventor: Ziro Aimono, applicant: Casio Computer Co., Ltd.) 
None of the above mentioned conventional electronic percussion instruments, 
however, is capable of storing in real time tone pitch data corresponding 
to the struck members in accordance with striking operation or is capable 
of reading out in real time the stored tone pitch data to sequentially 
reproduce musical tones each having a tone pitch corresponding to the read 
out tone pitch data. 
Therefore, it was impossible for a beginner player to exercise a percussion 
performance, listening to a model percussion performance given by a 
musician which has been recorded or impossible to check poor portions in 
his percussion operation listening to his own percussion performance. As a 
result, it was difficult to effectively exercise a percussion performance. 
Note that the electronic percussion instrument described in the above 
mentioned Japanese Utility Model Disclosure (Kokai) Nos. 58-16693 and 
60-76399, and U.S. Pat. No. 4418598 is capable of storing in real time 
output signals generated by the vibration sensor or a touch sensor 
provided on the drum, but is not capable of selectively generating musical 
tones each having a particular tone pitch in response to percussion 
operation. Therefore, this electronic musical instrument can not store 
melody data and chord data in real time. 
The electronic percussion instrument described in the above Japanese Patent 
Disclosure (Kokai) No. 61-23929 can be controlled to switch timbre of a 
musical tone to be generated, stop sounding of a musical tone and add 
tremolo, vibrato, sustain effects and the like to musical tones by 
operating switches provided on the instrument body. Therefore, in this 
electronic musical instrument, various timbre of performance by percussion 
operation can be enjoyed and a variety of performance expressions can be 
realized. However, in this electronic percussion instrument, the musical 
tone parameters for timbre, various effects and the like are set by 
operating switches provided on the instrument body. Therefore, it is 
difficult to change characters of musical tone being sounded without 
causing any trouble in performance, while the player is playing the 
percussion instrument with mallets in both his hands. 
In the electronic percussion instrument disclosed in the above Japanese 
Patent Disclosure (Kokai) No. 61-239299, striking intensity and striking 
position on the sound plate are detected and the musical tone characters 
such as tone pitch, timbre, tone volume, i.e, musical tone parameters are 
controlled in accordance with the detected striking intensity and striking 
positions. Therefore, in this percussion instrument, without operation of 
various switches provided on the instrument body, the musical tone 
characters can be controlled depending on the method for playing the 
instrument. However, the characters of a musical tone are determined at 
the time of striking operation. As a result, it is impossible to control 
or change the parameters of a musical tone being sounded. 
SUMMARY OF THE INVENTION 
The present invention has been made to overcome the above mentioned 
conventional disadvantages caused in the electronic percussion instruments 
mentioned above. 
An object of the present invention is to provide an electronic percussion 
instrument used for effectively exercising and practising percussion 
performance. 
Another object of the present invention is to provide an electronic 
percussion instrument capable of storing precisely and in real time, for 
example, model percussion performances by musicians and his own percussion 
performances. 
An additional object of the present invention is to provide an electronic 
percussion instrument capable of storing in real time, for example, melody 
data and chord data in response to percussion operation. 
A further object of the present invention is to provide an electronic 
percussion instrument which allows the player to control to rapidly and 
surely change parameters (for example, timbre, tone pitch, tone effect) of 
a musical tone being sounded or of a musical tone to be generated, even 
while he is performing percussion operation with striking members in both 
his hands. 
According to the present invention, to achieve the above mentioned objects, 
there is provided an electronic percussion instrument comprising: 
a plurality of percussion members adapted to be struck, each provided for 
each of tone pithes; 
percussion detection means for detecting a state of percussion imparted to 
said percussion members; 
performance-data generation means for generating during a percussion 
performance, percussion data and tone pitch data, said percussion data 
corresponding to states of percussion sequentially detected by said 
percussion detection means and said tone pitch data corresponding to the 
struck percussion members; and 
memory means for sequentially storing the percussion data and the tone 
pitch data generated by said performance-data generation means. 
The expression in claim 1, ". . . provided for each of tone pitches" has a 
wide concept including ". . . provided in order of the musical scale . . 
." and ". . . provided regardless of the order of the musical scale . . . 
". 
According to the present invention, there is provided an electronic 
percussion instrument comprising: 
a plurality of percussion members adopted to be struck, each provided for 
each of tone pitches; 
at least one striking member used for striking said percussion member; 
designation-data output means provided on said striking member, for 
outputting designation data to designate a parameter of a musical tone to 
be generated; 
percussion detection means for detecting a state of percussion applied to 
said percussion members; 
performance-data generation means for generating, during a percussion 
performance, percussion data and tone pitch data, said percussion data 
corresponding to states of percussion detected sequentially by said 
percussion detection means and said tone pitch data corresponding to the 
struck percussion members; and 
memory means for sequentially storing the percussion data and the tone 
pitch data generated by said performance-data generation means and the 
designation data output by said designation-data output means. 
The term, "a parameter of a musical tone has wide concept including various 
effect to be applied to a musical tone such as tremolo effect, vibrato 
effect and the like, in addition to timbre, tone pitch and tone volume. 
According to the present invention, there is provided an electronic 
percussion instrument comprising: 
a plurality of percussion members adopted to be struck, provided for a 
plurality of tone pitches; 
striking member used for striking said percussion members; 
percussion detection means for detecting a state of percussion applied to 
said percussion members to output a corresponding sensed signal; 
tone-pitch data generation means for generating tone pitch data 
corresponding to said percussion members, percussion applied to which is 
detected, on the basis of the sensed signal output by the percussion 
detection means; 
indication signal output means provided on said striking members, for 
outputting an indication signal to indicate a parameter of a musical tone 
to be generated; and 
control means for controlling a parameter having a tone pitch corresponding 
to the tone pitch data in accordance with the indication signal output by 
said indication signal output means, said tone pitch data generated by 
said tone pitch data generation means on the basis of the sensed signal 
output by said percussion detection means.

Now, hereinafter, embodiments of the present invention will be described 
with reference to the drawings. 
Whole Construction of a System 
FIG. 1 is a view showing an overall system construction of a first 
embodiment according to the present invention applied to an electronic 
percussion instrument. 
A control circuit (CPU) 1 comprises a micro-processor and executes a 
program stored in an internal Read Only Memory (ROM) (not shown) to 
control the overall system. 
A timer 2 generates various timer-interruptions at predetermined periods to 
apply the same to the control circuit 1. 
When received the timer-interruptions, the control circuit 1 reads out the 
program corresponding to the timer-interruptions to execute various 
processings and counts the present time. 
A mode selection switch 3 serves to select a mode out of a normal mode, a 
recording mode and a play back mode. 
In the normal mode, percussion performance is executed in real time and in 
the recording mode, melodies played in percussion performance are recorded 
in real time. In the play back mode, the melodies recorded in the 
recording mode are reproduced for automatic play. 
When the mode selection switch 3 is operated, a switch terminal 3a 
corresponding to the selected mode and a terminal 3b to which voltage V is 
applied from a power supply (not shown) are connected and thereby a 
logical value "1" is applied through an interface (not shown) to an input 
port of the control circuit 1 connected to the switch terminal 3a 
corresponding to the selected mode. The control circuit 1 scans at a 
predetermined period the input ports corresponding to the switch terminals 
3a of respective modes, when received the timer interruption from the 
timer 2 and discriminates what mode is selected at present on the basis of 
the value of the input ports. The mode selected at present, which is 
discriminated as a result of the scan, is stored in a predetermined memory 
area (not shown). 
A sound source circuit 4 serves to generate musical tones corresponding to 
musical tone control data supplied from the control circuit 1. The sound 
source circuit 4 comprises a sound source circuit 4a for a left hand 
mallet and a sound souce circuit 4b for a right hand mallet. The circuit 
construction of the sound source circuit 4 will be described in detail 
later. 
A sound system 6 comprises an amplifier and a speaker and produces sounds 
of musical tones generated by the sound source circuit 4. 
A sound-plate percussion detection selection 10 is a block for detecting 
percussion intensity of a sound plates 11 and vibration duration of the 
sound plates 11, both caused when a player striks the sound paltes 11 with 
a left hand mallet 20L or a right hand mallet 20R. The sound-plate 
percussion detection section 10 is provided for each of the sound plates 
11. 
The sound-plate percussion detection section 10 comprises a sound plate 11, 
a sound plate sensor 11A installed in the sound plate 11, a gate 12, an 
amplifier 13, and A/D converter 14, a register section 15, a peak 
detection section 16 and a vibration-duration detection circuit 17. 
The sound-plate sensor 11A serves to sense vibration state of a struck 
sound plate and can independently sense vibration state of each divided 
portion of the sound plate 11, which is equally divided into three 
portions. In the present embodiment, as will be described later, the 
sound-plate sensor 11A is installed in the sound plate 11. A sound plate 
11 is prepared for each of tone pitches ranging over several octaves. A 
plurality of the tone pitches 11 having a similar shape to those of a 
conventional acoustic percussion instrument are disposed on a supposed 
plane in order of the tone pitch. 
In FIG. 1, a symbol 11L denotes a sensor for sensing vibration of the left 
hand divided portion of the sound plate 11, a symbol 11C denotes a sensor 
for sensing vibration of the center divided portion of the sound plate 11 
and a symbol 11R denotes a sensor for sensing vibration of the right hand 
divided portion of the sound plate 11. 
When the sound plate 11 is struck with mallets 20 (hereinafter, the mallets 
20L and 20R are collectively referred to as mallets 20), the sound plate 
11 starts its vibration. The sensed signals S1, S2 and S3 representing 
vibrations at each portion on the sound plate 11 are output from the 
sound-plate sensors 11L, 11C and 11R, respectively. The output signals S1, 
S2 and S3 of the sound-plate sensors 11L, 11C and 11R are vibration 
waveforms representing vibration of each portion of the sound plate 11. 
The maximum amplitude value of the vibration and the vibration duration 
are almost inversely proportional to a distance between the struck 
position and the position at which the sound-plate sensor is installed. 
Therefore, the peak value of the amplitude of the vibration and the 
vibration duration are maximum, when these values are obtained from the 
vibration waveform output from the sound-plate sensor which is installed 
most close to the struck portion on the sound plate 11. The stronger the 
percussion operation to the sound plate 11 is, the larger the peak value 
of the amplitude and the vibration duration of the sensed signals S1, S2 
and S3 become. 
When the gate 12 receives pulse signals PL, PC and PR from the control 
circuit 1 at a predetermined period, the gate 12 is brought closed, 
thereby transferring the sensed signals S1, S2 and S3 to the amplifier 13. 
The sensed signals S1, S2 and S3 are amplified by the amplifier 13 and are 
converted to digital data M1, M2 and M3 having a predetermined number of 
bits corresponding to magnitude of the sensed signals S1, S2 and S3 and 
thereafter are supplied to the register section 15. 
The register section 15 comprises three registers 15a, 15b and 15c, in each 
of which digital data M1, M2 and M3 are stored, respectively. The 
registers 15a, 15b and 15c of the register section 15 are adapted to 
receive pulse signals PL, PC and PR. The registers 15a, 15b and 15c in the 
register section 15 store digital data M1, M2 and M3 respectively every 
time they receive the pulse signals PL, PC and PR. The digital data M1, M2 
and M3 stored respective registers 15a, 15b and 15c in the register 
section 15 are further output to the peak detection circuit 16 and the 
vibration-duration detection circuit 17. In this manner, the control 
circuit 1 applies the pulse signals PL, PC and PR to the gate 12 at a 
predetermined period, thereby scanning at a predetermined period the 
sensed signals S1, S2 and S3 output by the sound-plate sensors 11L, 11C 
and 11R. The scanned sensed signals S1, S2 and S3 are converted to digital 
data M1, M2 and M3 through the amplifier 13 and the A/D converter 14. The 
digital data M1, M2 and M3 are stored in the register section 15. The 
digital data M1, M2 and M3 stored in the register section 15 are supplied 
directly to the control circuit 1 and also to the peak detection circuit 
16 and the vibration-duration detection circuit 17. 
The peak detection circuit 16 serves to detect peak values P1 to P3 of the 
amplitudes of respective sensed signals S1 to S3 on the basis of the 
digital data M1 to M3 and to output the detected peak values P1 to P3. The 
circuit construction of the peak detection circuit 16 will be described in 
detail later. 
The vibration-duration detection circuit 17 serves to detect the vibration 
durations (the time duration in which the sound plate keep its vibration) 
of the sensed signal S1 to S3 on the basis of variations of the digital 
data M1 to M3 and to output the detected vibration durations t1 to t3 to 
the control circuit 1. The vibration-duration detection circuit 17 also 
outputs trigger signals T1 to T3 indicating the start and end of vibration 
of each divided portion of the sound plate 11 to the control circuit 1. 
When received the trigger signals T1 to T3 indicating the end of 
vibration, the control circuit 1 applies control signals a1 to a3 to the 
peak detection circuit 16 and control signals b1 to b3 to the 
vibration-duration detection circuit 17 and reads in peak values P1 to P3 
and vibration durations t1 to t3 from respective circuits. The detailed 
circuit construction of the vibration-duration detection circuit 17 will 
be described later. 
As described above, when the player of the instrument strikes an arbitrary 
sound plate 11, the sound-plate sensors 11L, 11C and 11R installed to the 
struck sound plate 11 output the sensed signals S1 to S3 representing 
vibration state of each divided portion of the sound plate 11. The control 
circuit 1 sequentially outputs pulse signals PL, PC and PR to the 
sound-plate percussion detection section 10, thereby sampling at a 
predetermined period the sensed signals S1 to S3 output from the 
sound-plate sensor 11A of each sound plate 11. The peak detection circuit 
16 detects peak values P1 to P3 of the vibration amplitude of each divided 
portion of the sound plate 11 on the basis of the sampling data M1 to M3 
of the sensed data S1 to S3. The vibration-duration detection circuit 17 
detects vibration durations t1 to t3 of each divided portion of the sound 
plate 11 on the basis of the sampling data M1 to M3 when the sound plate 
11 is struck with the mallet 20L (20R). Further, the vibration-duration 
detection circuit 17 supplies the trigger signals indicating the start and 
end of the vibration of each divided portion of the sound plate 11 to the 
control circuit 1. 
The mallets 20L and 20R are striking members of a mallet shape, used for 
striking the sound plate 11. On the mallets 20L and 20R, as will be 
described in detail later, are provided timbre-selection switches 61 to 63 
for selecting timbre and musical-tone control switches 41 to 43, as shown 
in FIG. 3. When the timbre-selection switches 61 to 63 are operated, 
timbre-selection data are output to the control circuit 1. The control 
circuit 1 reads in the timbre selection data at a predetermined period and 
discriminates the timbre designated by the timbre-selection switches 61 to 
63. The control circuit 1 produces timbre data corresponding to the 
designated timbre and outputs the same to the sound source circuit 4. 
A vibration sensor 65 is provided on the mallets 20L and 20R, which sensor 
senses vibration of mallet portions 21L and 21R of the mallets 20L and 
20R, caused when the sound plate 11 and portion other than the sound plate 
11, for example, a table surface are struck with the mallets 20L and 20R. 
The vibration of the mallets portions 21L and 21R is sensed by the 
vibration sensor 65 and is supplied to the gate 31 as sensed signals S4 
and S5. 
Furthermore, a gate 31, an amplifier 32, an A/D converter 33, a register 
section 34, a peak detection circuit 35 and a vibration-duration detection 
circuit 36 are prepared and these circuits are the same as those having 
like references in the sound-plate percussion detection section 10. A 
further description thereof will be omitted. The gate 31 comprises two 
gates, the register section 34 comprises two registers 34a and 34b. The 
digital data M4 and M5 corresponding to the above mentioned sensed signals 
S4 and S5 are stored in the register section 34. 
The control circuit 1 applies sequentially pulse signals PL4 and PL5 to the 
gate 31 at a predetermined period and thereby scanes at a predetermined 
period the sensed signals S4 and S5 sensed by the vibration sensors 65 
installed in the above mallets 20L and 20R. 
When received the pulse signals PL4 and PL5, the gate is brought closed, 
thereby transmitting the sensed signals S4 and S5 to the amplifier 32. The 
amplified signals S4 and S5 are supplied to the A/D converter 33. The 
sensed signals S4 and S5 are converted to digital data M4 and M5 by the 
A/D converter 33 and thereafter are stored in the register section 34. The 
digital data M4 and M5 stored in the register section 34 are supplied 
through a flip-flop circuit 34 to the peak detection circuit 35 and the 
vibration-duration detection circuit 36. 
The peak detection circuit 35 detects peak values of vibrations of the 
mallet sections 21L and 21R in the mallets 20L and 20R, sensed by the 
above vibration sensors 65 on the basis of the received digital data M4 
and M5. Further, the peak detection circuit 35 outputs the detected peak 
values P4 and P5 of the vibrations to the control circuit 1. 
The vibration-duration detection circuit 36 detects vibration durations t4 
and t5 of the vibration of the mallet sections 21L and 21R in the mallets 
20L and 20R, sensed by the above vibration sensor on the basis of 
variations of the input digital data M4 and M5. The detected vibration 
durations t4 and t5 are supplied to the control circuit 1. The trigger 
signals T4 and T5 indicating the start and end of vibration of the mallet 
sections 21L and 21R are also transferred to the control circuit 1. 
When received the trigger signals T4 and T5 indicating the end of 
vibration, the control circuit 1 applies control signals a4 and a5 to the 
peak detection circuit 35 and control signal b4 and b5 to the vibration 
duration detection circuit 36, thereby reading in peak values P4 and P5, 
and vibration durations t4 and t5. 
Sound Source Circuit 4 
FIG. 2 is a view illustrating one circuit construction of the sound source 
circuit 4A for the left hand mallet and the sound source circuit 4B for 
the right hand mallet. The sound source circuits 4A and 4B comprise a 
latch circuit 21, a frequency data ROM, an accumulator 23, a waveform 
memory (PCM) 24, a digital amplifier 25, an envelope generator 26, a 
digital signal processor (DSP) 27 and a D/A converter 28. 
The latch circuit 21 latches timbre data TONL (TONR), tone pitch data(KDT), 
musical tone control data (MCNTD) (envelope control data ENVC, effect data 
EFD and the like) supplied from the control circuit 1, every time it 
receives an enable signal EL (ER) from the control circuit 1. The latch 
circuit 21 outputs tone pitch data KDT to the frequency data ROM 22, 
timbre data TL (TR) to the waveform memory 24, envelope control data ENVC 
to the envelope generator 26, effect control data EFD, rapid tone cease 
instruction data ERD, sustain effect adding data SUSTD, and tremoro effect 
adding data TRD to the digital signal processor 27. 
The frequency data ROM 22 comprises a Read Only Memory (ROM) storing 
frequency data corresponding to respective tone pitches. When tone pitch 
data KTD is applied to the frequency data ROM 22, this ROM 22 outputs 
frequency data F corresponding to the applied tone pitch data KTD to the 
accumulator 23. The frequency data is set such that the data F takes 
larger value as the tone pitch becomes higher. 
The accumulator 23 serves to accumulate frequency data F supplied from the 
frequency data ROM 22. The accumulator 23 accumulates frequency data F 
until the accumulated frequency data F reaches a predetermined maximum 
value and repeats the same operation when the accumulated frequency data F 
reaches the predetermined maximum value. Therefore, as the frequency data 
F takes a larger value or the musical tone is higher, the repeat-frequency 
of the operations becomes higher. Inversely, as the musical tone is lower, 
the repeat-frequency of the operations becomes lower. The repeat-frequency 
corresponds to the period of the musical-tone waveform. Therefore, as the 
musical tone becomes higher, the repeat-frequency of the operations or the 
frequency of musical tones becomes higher. The accumulated value TF of the 
accumulator 23 is added to the waveform memory as the least-significant 
address data. The timbre data TONL (TONR) is applied from the latch 
circuit 21 to the waveform memory 24 as the most-significant address 
signal. 
The waveform memory 24 comprises ROM (Read Only Memory) storing sample data 
of one period of timbre waveforms of various musical instruments, which 
sample data are pulse-code modulated. When the waveform memory 24 receives 
the timbre data TONL (TONR) and the address signal composing of the 
accumulated value TF output from the accumulator 23, waveform sample data 
WS of a musical tone waveform of a note having a timbre designated by the 
timbre data TONL (TONR) is read out from the waveform memory 24 and is 
applied to the digital amplifier 25. In this case, the operation for 
reading out the waveform sample data WS from the waveform memory 24 is 
executed in accordance of the repeat-frequency of the accumulation of the 
accumulator 23. Therefore, the waveform data supplied to the digital 
amplifier 25 becomes a tone pitch designated by the tone pitch data KDT. 
The digital amplifier 25 serves to multiply the waveform sample data WS 
supplied from the waveform memory 24 and envelope data ENVD applied from 
the envelope generator 26, thereby generating a musical-tone wave-form DM 
having the designated timbre. 
The envelope generator 26 serves to apply envelope data ENVD having a 
predetermined amplitude to the digital amplifier 25 on the basis of the 
envelope control data ENVC of the latch circuit 21 and control tone volume 
of a musical tone on the basis of the envelope control data ENVC. 
The digital amplifier 25 multiplies sample data WS of a musical tone 
waveform input from the waveform memory 24 as described above and the 
amplitude envelope data ENVD applied from the envelope generator 26 to 
generate a digital musical-tone signal DM and outputs the signal DM to the 
digital signal processor (DSP) 27. The digital signal processor 27 applies 
various effects such as reverberation and echo to the digital musical-tone 
signal DM on the basis of the effect control data EFD supplied from the 
latch circuit 21 and thereafter outputs the signal DMS to the D/A 
convertor 28. The D/A converter 28 converts the digital musical-tone 
signal DMS supplied from the digital signal processor 27 to an analog 
musical-tone signal AM and output the same to the mixing circuit 10. 
The accumulator 23, envelope generator 66 and digital amplifier 25 can 
execute time-division operation under control of the control circuit 1. 
The control circuit 1 assigns musical tone data (such as timbre data TOND, 
tone pitch data KDT, effect data PDT) corresponding to a plurality of 
striking operations to each channel and causes the latch circuit 21 to 
latch the musical tone data assigned to each channel at a timing of each 
channel. The musical tones generated at respective channels in this manner 
are composed by the digital signal processor 27 and then the composed 
signal is converted to an analog musical tone signal AM by the D/A 
converter 28. Therefore, a plurality of sounds can be acoustically output 
at the same time. 
The analog musical tone signal AM is acoustically output as a music through 
the sound system 6. 
Mallet 20 
FIG. 3 is an exploded perspective view showing one construction of the 
mallet 20. A handle portion of the mallet 20 consists of hollow members 
52A and 52B which are combined to each other to form a cylinder. The upper 
half member 52B of the handle portion is provided with tapped through 
holes 53 and 54 in the vicinities of its front and tail ends. The lower 
half member 52A is also provided with tapped holes 55 and 56 at portions 
corresponding to the tapped through holes 53 and 54 formed in the upper 
half member 51A. The hollow members 52A and 52B are combined by means of 
screws 57 and 58 screwed through the tapped through holes 53 and 54 to the 
tapped holes 55 and 56. In a concave room provided at the central portion 
of the lower half member 52A, a printed circuit board 60 is received. On 
the printed circuit board 60, three switches 61, 62 and 63 of a push 
button type are installed for selecting timbres. 
The timbre-selection switches 61, 62 and 63 are used to select various 
timbres such as marimba, piano and guitar timbres. At the portions on the 
upper half member 52B, corresponding to timbre-selection switches 61, 62 
and 63, there are provided cover cases 61A, 62A and 63A for covering the 
switches 61, 62 and 63. Every time, the cover cases 61A, 62A and 63A are 
depressed, the switches 61, 62 and 63 are alternatively turned on or 
turned off. 
To the left hand end of the printed circuit board 60, as viewed in FIG. 3, 
a lead line 64 is connected, and to the right hand end of the printed 
circuit board 60, a cord 65 is connected. The switches 61, 62 and 63 are 
electrically connected to the cord 65 through wiring pattern on the 
printed circuit board 60. When the switches 61, 62 and 63 are turned on by 
depressing operation, predetermined electric signals are output to the 
control circuit 1 through the cord 65. The lead 64 forms an eye-ball like 
space nearly at its center portion in which space a tapped hole portion 55 
on the hollow member 52A is received. The other end of the lead 64 is 
connected to a pressure sensor 65. The front portion of the pressure 
sensor 65 is received by a recess (not shown) formed in an end portion of 
a buffer stuff 66 of a cylinder shape. The buffer stuff 66 is adapted to 
be pressed into a receiving portion 21a of the mallet portion 21. The 
pressure sensor 65 is received in the hollow member 52. The mallet portion 
21 is combined with the handle portion by means of the buffer stuff 66. 
When the mallet portion 21 is struck, the vibration of the mallet portion 
21 is weaken by the buffer stuff 66 and transferred to the pressure sensor 
65. The pressure sensor 65 outputs a sensed signal expressing the 
vibration of the mallet portion 21. The sensed signal is conveyed to the 
control circuit 1 through the lead line 64, the printed circuit board 60 
and the cord 65. The amplitude of the sensed signal is proportional to the 
strength of the striking the mallet portion 21. 
As the timbre selection switches 60, 61 and 62 are disposed at positions 
where the player of the mallet 5L (5R) are allowed to easily operate them, 
the player can switch the timbre by simple operation during playing 
operation. 
On the printed circuit board 60, a variable resistor or a rheostat 51 is 
mounted. A pitch-bend operating member 52 of a wheel shape is fixed to the 
side face of the rheostat 51 for controlling the resistance value. The 
rheostat 51 is arranged on the circuit board 60, such that the upper 
portion of the pitch-bend operating member 52 is exposed through a hole 
53A formed in the hollow member 52B. The pitch-bend operating member 52 is 
rotatable and the resistance value of the rheostat is changed depending on 
the rotating direction and rotating angle of the pitch-bend operating 
member 52. The pitch-bend operating member 52 has a notched peripheral 
surface for easy operation with a finger. 
Variation of resistance value of the rheostat 51 is converted to a relavant 
voltage, which is supplied through the cord 65 to the control circuit 1. 
The control circuit 1 reads in the above voltage at a predetermined period 
to generate pitch-bend data PDT for controlling a tone-pitch of a musical 
tone. The control circuit 1 outputs the pitch-bend data PDT to the sound 
source circuit 4A for the left hand mallet or the sound source circuit 4B 
for the right hand mallet depending on the mallet, the pitch-bend 
operating member is operated. 
The switches 41, 42 and 43 mounted on the printed circuit board 60 serves 
to apply sustain effect, rapid tone cease instruction and tremolo effect, 
respectively. More specifically, the switch 41 serves to instruct to apply 
sustain effect to a musical tone being generated, the switch 43 serves to 
instruct to apply tremolo effect to a musical tone being generated and the 
switch 42 serves to instruct to rapidly cease sound of a musical tone 
being generated. 
When the above switches 41, 42 and 43 are turned on, on-operation signals 
are delivered from the switches 41, 42 and 43 to the control circuit 1. 
When the control circuit 1 receives on-operation signal of the above 
switches 41, 42 and 43, the circuit 1 produces the sustain effect adding 
data SUSTD, the rapid tone-cease instruction data ERD and the tremolo 
effect adding data TRD in accordance with the instructions of the above 
respective switches and supplies these data to the sound source circuit 
48A or 48B corresponding to switch operated mallet 20L (20R). 
Sound Plate 11 (Sound Plate Sensor 11A) 
FIG. 4 is a sectional view showing one construction of a sound plate 11. In 
this construction, the sound plate 11 and a sound plate sensor 11A are 
combined in one unit. 
The sound plate 11 is of a laminate construction. The laminate construction 
consists of an insulating base plate 70, three under electrode members 
71L, 71C and 71R separately and in parallel stacked on the above 
insulating base plate 70, an elastic conductive member 72 formed on the 
upper surfaces of the above under electrode members 71L, 71C and 71R, an 
upper electrode member 73 provided on the upper surface of the above 
elastic conductive member 72 and an insulating facing member 74 laminated 
on the upper electrode member 73. The elastic conductive member 72 
consists of, for example, conductive rubber foam (resistivity, 
approximately 1 to 10.omega. cm). The upper electrode member 72 consists 
of, for example, rubber of high conductivity (resistivity, approximately 
10.sup.-2 .omega.cm). The facing member 74 consists of, for example 
insulating rubber and may be formed integrally with the facing member of 
other sound plate 11. 
A terminal T is connected to the upper electrode member 73 and terminals 
TL, TC and TR are connected to the under electrode members 71L, 71C and 
71R, respectively. Resistances RL, RC and RR are provided between the 
terminal T and the terminals TL, TC and TR, respectively. 
The sound plate sensor 11L is composed of the upper electrode member 73, 
the elastic conductive member 72 and the under electrode member 71L, and 
similarly the sound plate sensors 11C and 11R are composed of the upper 
electrode member 73, the elastic conductive member 72 and the under 
electrode members 71C and 71R, respectively. That is, the sound plate 
sensor 11A comprises three sound plate sensors 11L, 11C and 11R for 
sensing vibration of three-divided portions of the sound plate. 
When the surface of the sound plate 11 is struck with the mallet portion 
21L of the mallet 20L (20R), distances between the upper pelectrode member 
73 and the under electrode members 71L, 71C and 71R decrease. As a result, 
the resistivity of the elastic conductive member 72 is reduced. Therefore, 
resistance of resistors RL, RC and RR of the sound plate sensors 11L, 11C 
and 11R are also reduced. Resistance variation of resistors RL, RC and RR 
of the sound plate sensor 11A becomes maximum, when the portion on the 
sound plate 11 closest to them is struck. In this manner, the sound plate 
sensors 11L, 11C and 11R sense the intensity of striking operation in 
terms of variations of resistances RL, RC and RR. The variations of 
resistances RL, RC and RR of the sound plate sensors 11L, 11C and 11R are 
converted to electric signals and supplied to the gate 12. That is, 
electric signals representing vibrations of respective portions of the 
sound plate 11 are output from the sound plate sensors 11L, 11C and 11R. 
In this manner, since vibrations of respective portions of the sound plate 
11 can be independently sensed, the striking operation can be detected 
without failure regardless of the struck position. 
Peak Detection Circuit 
FIG. 5 is a circuit diagram showing one circuit construction of peak 
detection circuits 16 and 35. In practice, in the peak detection circuits 
16 and 35 shown in FIG. 1, there are provided in parallel the same number 
of the peak detection circuits as shown in FIG. 5 as the input number of 
the digital data MK (K=1 to 5). 
A circuit for detecting peak values PK of digital data KK comprises a latch 
circuit 101 for latching digital data MK, a latch circuit 102 for latching 
outputs of the latch circuit 101 and a comparator 103 for comparing 
outputs of the latch circuits 101 and 102. 
When received a latch signal aK from the control circuit 1 shown in FIG. 1, 
the latch circuit 101 latches digital data MK supplied from the latch 
circuit 15. For example, the latch signal aK is applied to the latch 
circuit 101 after a predetermined time delay after generation of pulses P 
(pulses PL, PC, PR, PL4 and PL5 are collectively referred to as pulses P). 
More specifically, the sensed signal SK passes through the gate 12 (31) to 
which the pulses P are applied and is converted to digital data MK by the 
A/D converter 14 (33), and thereafter the latch signal aK is applied to 
the latch circuit 101. As a result, the latest digital data MK of the 
scanned sensed-signal SK of the sound plate sensor 11A (or a pressure 
sensor element 65) is latched in the latch circuit 101. For convenience, 
the digital data latched in the latch circuit 101 is represented by "NEW". 
At first, the latch circuit 102 is set to the initial value "0" and the 
outputs of the latch circuits 101 and 102 are applied to the comparator 
103. Again, for convenience, latched data of the latch circuit is 
represented by "OLD". 
The comparator 103 compares the output NEW of the latch circuit 101 and the 
output OLD of the latch circuit 102. If NEW is larger than OLD, the 
comparator 103 generates the output "1". If NEW is equal to or smaller 
than OLD, the comparator generates the output "0". The output of the 
comparator 103 is applied to the latch circuit 102 as a latch signal 
l.sub.1. The latch circuit 102 latches the output NEW of the latch circuit 
101 at the trailing edge of the latch signal l.sub.1 ("1" "0"). Therefore, 
the maximum value among the digital data MK to be input to the peak 
detection circuit 16 is latched in the latch circuit 102. 
For example, when the sensed signal SK as shown in FIG. 7 is sensed by the 
sound plate sensor (or a pressure sensor element 65), the digital data MK 
is input to the peak detection circuit 16, which digital data MK 
corresponds to the sensed signal SK sampled at the period of the pulse 
signal PK which is applied to the gate 12 (31). When the peak value PK of 
the sensed signal SK shown in FIG. 7 is latched in the latch circuit 101, 
the latch signal l.sub.1 is applied from the comparator 103 to the latch 
circuit 102 and the peak value PK is latched in the latch circuit 102. 
Since the sensed signal SK is gradually decreased thereafter, the digital 
data Mi to be sampled by no means becomes larger than the above peak value 
PK. Therefore, the latch circuit 102 holds the peak value PK. The control 
circuit 1 detects the end of the vibration of the sound plate 11, when the 
vibration-duration detection circuit 17 as will be described in detail 
later, output a trigger signal indicating the end of the vibration. Then 
the control circuit 1 fetches the peak value PK latched in the latch 
circuit 102. 
Vibration-Duration Detection Circuits 17 and 36 
FIG. 6 is a view showing one construction of the vibration-duration 
detection circuits 17 and 36 shown in FIG. 1. 
Actually, in the vibration-duration detection circuits 17 and 36, there are 
provided in parallel the same number of vibration-duration detection 
circuits shown in FIG. 6 as the input number of digital data MK. 
A circuit for detecting vibration duration on the basis of the digital data 
MK comprises latch circuits 111 and 113 for latching the digital data MK, 
a latch circuit 112 for latching the output of the latch circuit 111, a 
comparator for comparing outputs of the latch circuits 111 and 112, a 
comparator 114 for comparing the output of the latch circuit 113 and a 
predetermined threshold value TH and a counter 117 to which the output of 
the comparator 114 is applied. Receiving a latch signal bK from the 
control circuit 1, the latch circuit 111 latches the digital data MK. 
Receiving a latch signal bK, the latch circuit 112 latches the output (for 
convenience, the output is referred to as NEW 1) of the latch circuit 111. 
Therefore, the latch circuit 111 retains the latest (present) digital data 
MK and the latch circuit 112 retains the preceding digital data MK. The 
comparator 114 compares the output (the present digital data MK) of the 
latch circuit 111 and the output (the preceding digital data MK) of the 
latch circuit 112. If the present digital data MK is larger than the 
preceding digital data MK (NEWi&gt;OLDi), the comparator 114 generates the 
output l.sub.2 "1", and if the present digital data Mi is equal to or 
smaller than the preceding digital data Mi (NEWi.ltoreq.OLDi), the 
comparator 114 generate the output l.sub.2 "0". 
In case that the sensed signal SK (amplified by the amplifier 13 or 32) has 
such a waveform as shown in FIG. 7 and the threshold value TH is set at 
such a value as shown in FIG. 7, a latch signal l.sub.2 output from the 
comparator 114 is a pulse signal as shown in FIG. 7 and is applied to the 
latch circuit 113. 
The latch signal l.sub.2 drops abruptly from a high level "1" to a low 
level "0" at the time the sensed signal Si turns from the positive peak 
value towards the negative peak value and rises abruptly from a low level 
"0" to a high level "1" at the time the sensed signal Si turns from the 
negative peak value towards the positive peak value. 
The latch circuit 113 latches the digital data MK output from the register 
15 (or 34) shown in FIG. 1 at the trailing edge of the latch signal 
l.sub.2. The comparator 115 compares the output 0.sub.3 of the latch 
circuit 113 and the threshold value TH. When the output 0.sub.3 of the 
latch circuit 113 is larger than the threshold value TH, the comparator 
115 outputs a signal "1". When the output 0.sub.3 of the latch circuit 113 
is equal to or smaller than the threshold value TH, the comparator 115 
outputs a signal "0". Therefore, the output C of the comparator 115 
retains a value "1" while the peak values, at every period, of the sensed 
signal SK latched in the latch circuit 113 are larger than the threshold 
value TH, as shown in FIG. 7. As a result, the trigger signal TK output 
from the comparator 115 retains a high level "1" until the sensed signal 
Si decreases to be equal to or less than a predetermined value. The 
trigger signal TK is supplied to the counter 117 and the control circuit 
1. A clock signal (not shown) having a predetermined frequency is input 
from the timer 2 of FIG. 1 to the counter 117. The counter 117 counts the 
number of clock pulses input thereto while the enable signal (trigger 
signal) TK applied from the comparator 115 retains a level "1". That is, 
the counter 117 counts the number of pulses which is proportional to the 
vibration duration tK of the sensed signal SK, as shown in FIG. 7. If the 
period of the clock signal is set at a predetermined time unit, for 
example, 1 msec, the count value is equal to the vibration duration tK 
itself. 
The control circuit 1 detects the start of the vibration of the sound plate 
11 or the mallet portion 21L (21R) when the trigger signal TK input 
thereto from the vibration-duration detection circuit 17 (36) rises from a 
level "0" to a level "1". Further, the control circuit 1 detects the start 
of the vibration of the sound plate 11 or the mallet portion 21L (21R), 
when the trigger signal TK drops from a level "1" to a level "0". And also 
the control circuit 1 detects the end of the vibration of the sound plate 
11 or the mallet portion 21L (21R) when the trigger signal TK drops from a 
level "1" to a level "0". That is, the control circuit detects the 
percussion of the sound plate 11 or the mallet 20 at the leading edge of 
the trigger signal TK and detects the end of vibration of the sound plate 
11 or the mallet portion 21L (21R) at the trailing edge of the trigger 
signal TK. 
Now, the operations of the present embodiment in various modes will be 
described. 
Normal Mode 
The mode selection switch is brought to a normal mode position to set a 
normal mode. 
As described above, when a certain sound plate 11 is struck with the mallet 
20L (20R) in the normal mode, the vibration-duration detection circuit 16 
of the sound-plate percussion detection section 10 corresponding to the 
struck sound plate 11 applies the trigger signal Ti (i=1, 2) indicating 
the start of the vibration of the sound plate 11 to the control circuit 1. 
When received the trigger signal Ti indicating the start of the vibration 
of the sound plate 11, the control circuit 1 outputs to the sound source 
circuit 4 tone pitch data corresponding to the sound plate 11 connected to 
the sound-plate percussion detection section 10 which has output the above 
trigger signal Ti. Further, the control circuit 1 reads out at a certain 
period digital data M1 to M3 stored in the register section 15 of the 
sound-plate percussion detection section 10 which has output the trigger 
signal Ti, and produces envelope control data and effect control data such 
as echo and reverberation effects and then outputs these data to the sound 
source circuit 4. Since the trigger signal Tj (j=4, 5) indicating the 
start of the vibration of the mallet portion is applied to the control 
circuit 1 from the vibration-duration detection circuit 36 corresponding 
to the struck mallet 20 almost at the same time that the trigger signal Ti 
is supplied thereto, the control circuit 1 reads out the timbre selection 
data output from the timbre selection switches 61 to 63 of the struck 
mallet 20 and outputs the designated timbre data to the sound source 
circuit 4. Thereby, the sound source circuit 4 generates a musical tone 
which has a tone pitch corresponding to the struck sound plate 11 and also 
has a timbre selected by the timbre selection switches 61 to 63 of the 
struck mallet 20L (20R). The musical tone generated by the sound source 
circuit 4 is sounded through the sound system 6. 
Now, referring to FIGS. 9A through 9D, control operation of musical tones 
will be described which is executed when the switches 41 to 43 provided on 
the mallet 20L (20R) are operated right after the sound plate 11 is struck 
with the above mallet 20L (20R). Note that in FIGS. 9A through 9D, an 
amplitude envelope of a musical tone is indicated in a solid line 70 when 
no musical tone control is executed. 
When a particular sound plate 11 is struck with the mallet 20L (20R), tone 
pitch data corresponding to the above sound plate 11 is supplied to the 
sound source circuit 4 in response to the striking operation. Then, a 
musical tone having a tone pitch corresponding to the above tone pitch 
data is generated. During generation of the musical tone, the pitch-bend 
operating member 52 is turned. Then pitch bend data PDT corresponding to 
the above turning operation is supplied from the control circuit 1 to the 
latch circuit 21 (FIG. 2). 
The pitch bend data PDT latched in the latch circuit 21 is output to the 
accumulator 63. The accumulator 63 executes an accumulation-operation to 
obtain "F+PDT" by adding pitch bend data PDT to frequency data F applied 
from the frequency-data ROM 22. The control circuit 1 scans at a 
predetermined period voltage value expressing the resistance variation of 
the variable resistor 51 which is caused by the turning operation of the 
pitch-bend operating member 52. Further, the control circuit 1 outputs to 
the latch circuit 21 pitch-bend data PDT corresponding to the above 
voltage together with enable signal EL (ER) every time the above voltage 
is varied. 
As shown in FIG. 9D, when the sound plate corresponding to a tone pitch "x" 
(symbol x denotes an arbitrary tone pitch) is struck with the mallet 20L 
(20R) at the time T6 and thereafter the pitch-bend operating member 52 is 
turned at the time T7, the musical tone of a tone pitch X is changed in 
its pitch in response to the turning operation of the pitch-bend operating 
member 52 after the time T7 (Pitch Bend). 
When the switch 41 provided on the mallet 20L (20R) is operated, sustain 
effect adding data SUSTD is input to the latch circuit 21. The sustain 
effect adding data SUSTD latched in the latch circuit 21 is output to the 
envelope generator 66. When the sustain effect adding data SUSTD is 
applied, the envelope generator 66 thereafter keeps supplying to the 
digital amplifier 25 the envelope data which is output at the time the 
sustain effect adding data SUSTD is applied thereto. 
Accordingly, when the switch 41 is turned on to add the sustain effect at 
the time T1 in FIG. 9A the musical tone holds its tone volume at the level 
determined at the time T1 as indicated in a broken line in FIG. 9A until 
the switch 41 is turned off at the time T2 (Sustain). 
When the switch 42 provided on the mallet 20L (20R) is operated, rapid 
tone-cease instruction data ERD is input to the latch circuit 21. The 
rapid tone-cease instruction data ERD latched in the latch circuit 21 is 
output to the envelope generator 66. When the rapid tone-cease instruction 
data ERD is applied, the envelope generator 66 controls the envelope data 
ENVD to be supplied to the digital amplifier 25 so as to cause the 
amplitude envelope of the musical tone to rapidly reduce. 
Accordingly as shown in FIG. 9B, when the switch 42 is turned on at the 
time T3 to generate the rapid tone-cease instruction data, the tone volume 
of the musical tone reduces rapidly as indicated in a broken line in FIG. 
9B (Rapid Tone Cease). 
When the switch 43 provided on the mallet 20L (20R) is operated, tremolo 
effect adding data TRD is input to the latch circuit 21. The tremolo 
effect adding data TRD latched in the latch circuit 21 is output to the 
envelope generator 66. When the tremolo effect adding data TRD is applied, 
the envelope generator 66 controls the envelope data ENVD to be supplied 
to the digital amplifier 25 so as to cause the tone volume of the musical 
tone to increase and decrease by a somewhat small amount. 
Accordingly, when the tremolo effect switch 43 is operated at the time T4 
as shown in FIG. 9C, the tone volume of the musical tone fluctuates as 
indicated in a broken line 73 in FIG. 3 until the switch is operated at 
the time T5 (TremoloEffect). 
In the manner described above, after a certain sound plate 11 is struck 
with the mallet 20L (20R) to generatea musical tone 70 having a tone pitch 
corresponding to the struck sound plate 11, tremolo effect, pitch bend 
effect and sustain effect can be applied to the musical tone 70 which is 
being generated or sounding of the musical tone 70 can be stopped by 
operations of the switches 41 to 43 provided on the mallet 20L (20R) or 
the pitch-bend operating member 52. 
Recording Mode 
In the recording mode, a musical tone having a certain timbre is sounded in 
real time as described above, and percussion data of the sound data and 
percussion data of the mallet 20 are recorded in the sequencer RAM 7. 
Now, referring to the internal construction of the sequencer RAM 7 shown in 
FIG. 8, the recording operation of the control circuit 1 will be described 
which is executed in the recording mode to record the percussion data of 
the sound plate 11 and the mallet 20. 
When the trigger signal Tj (j=4, 5) indicating the start of the vibration 
is supplied from the vibration-duration detection circuit 36, the control 
circuit 1 reads out the counted present time and writes the present time 
in an operation (percussion) time area of the sequencer RAM 7. 
Note that the percussion time may be the time when the trigger signal Ti 
(i=1 to 3) indicating the start of the vibration is applied from the 
vibration-duration detection circuit 17 of the sound plate percussion 
detection section 10 to the control circuit 1. 
Further, the control circuit 1 reads in switch-operation data of the timbre 
selection switches 61 to 63 of the mallet 20L (20R) which outputs the 
above trigger signal Tj and judges the designated timbre based on the 
switch operation data. Then, the control circuit 1 writes the timbre data 
corresponding to the designates timbre in a timbre-selection data storing 
area 43C of a mallet data area 43 in the sequencer RAM 7, which 
corresponds to the struck mallet 20. 
The control circuit 1 watches the trigger signal Tj output from the 
vibration-duration detection circuit 36 and receives the peak value Pj 
from the peak detection circuit 35 when the trigger signal Tj indicating 
the end of the vibration is applied thereto. Then the control circuit 1 
writes the peak value Pj corresponding to the struck mallet 20 in a 
vibration level storing area 43a of the mallet data area 43 in the 
sequencer RAM 7, as shown in FIG. 8. In FIG. 8, the peak values written in 
the vibration level storing area 43a are expressed by "HIGH", "MEDIUM", 
but actually the peak values Pj are written instead of the above 
expression. Expressions "HIGH", "MEDIUM" represent the relative levels of 
the peak values. 
Furthermore, the control circuit 1 reads out the vibration duration tj 
corresponding to the struck mallet from the vibration-duration detection 
circuit 17 and writes the same in a vibration duration storing area 43b of 
the mallet data area 43. 
The control circuit 1 reads out peak values P1 to P3 from the peak 
detection circuit 16 corresponding to the struck sound plate 11 and 
vibration durations t1 to t3 from the vibration duration detection circuit 
17 and writes these data in the vibration level storing area 41b and the 
vibration duration storing area 41C of the sound plate data area 41 in the 
sequencer RAM 7, respectively. The control circuit 1 writes tone pitch 
data corresponding to the struck sound plate 11 in the tone-pitch storing 
area 41a of the sound plate area 41. 
Thereafter, in the recording mode, in the similar manner, the sound plate 
data concerning the percussion operation, the mallet data concerning the 
operation (percussion) times, percussion operation are sequentially 
written in the sequence RAM 7, every time the sound plate 11 is struck 
with the mallet 20, as shown in FIG. 8. 
Play Back Mode 
The mode selection switch 3 is operated to select the play back mode. Then 
the control circuit 1 reads out sequentially sound plate data 41, 
operation (percussion) times 42, mallet data 43 to produce tone pitch 
data, envelope control data and effect control data. Then, the control 
circuit 1 supplies the above tone pitch data, envelope control data and 
the effect control data to the sound source circuit 4 at a predetermined 
time interval on the basis of the operation (percussion) times, and 
thereby a recorded melody and the like are reproduced at the same 
performance tempo as that in the recording mode. 
Method of Setting Musical Tone Data 
Now, methods of setting tone pitch data, tone volume data, envelope control 
data and effect control data will be described which the control circuit 1 
employs. 
At first, the method of setting tone pitch data will be described. As 
described above, the control circuit 1, scans the sensed signals S1, S2 
and S3 sensed by the sound-plate sensors 11L, 11C and 11R at a 
predetermined period, while the control circuit 1 outputs pulse signals 
PR, PC and PL. Mean while, when the sound plate 11 is struck with the 
mallet 20, the trigger signal Tj indicating the start of the vibration is 
applied to the control circuit 1 from the vibration-duration detection 
circuit 17 of the sound-plate percussion detection section 10 
corresponding to the struck sound plate 11. 
The control circuit 1 finds the struck sound plate 11 by judging which 
sound-plate percussion detection section 10 has output the above trigger 
signal Tj to the control circuit 1. Then, the control circuit 1 sets the 
tone pitch data corresponding to the above sound plate 11 with reference 
to, for example, a tone-pitch convertion table stored in RAM (not shown). 
The envelop control data will be set as follows. The control circuit 1 
reads out peak valves P1, P2 and P3 from the peak detection circuit 16 of 
the sound-plate percussion detection section 10, when it receives the 
trigger signal Tj indicating the end of the vibration from the vibration 
duration detection circuit 17. Then the control circuit 1 set the tone 
volume based on the above peak values P1 to P3. 
The tone volume is set in accordance with the maximum value Max (P) among 
peak values P1 to P3. That is, the tone volume is set at a relatively low 
level for a relatively low value of Max (P) and is set at a relatively 
high level for a relatively high value of Max (P). In this manner, the 
tone volume is set in proportion to the value of Max (P). In other way, 
the tone volume can be set in proportion to SUM (P); the sum of peak 
values P1 to P3. In yet another way, certain tone volume is previously 
determined for each of divided portions of the sound plate and the tone 
volume may be set on the basis of the previously determined tone volume 
for the divided portion for which the peak value Pi (i=1 to 3) is maximum. 
As described above, when the trigger signals T1 to T3 indicating the end of 
the vibration from the vibration duration detection circuit 17, the 
control circuit reads out the vibration durations t1 to t3 from the 
vibration duration detection circuit 17. Then, the control circuit 1 sets 
the envelope control data to control the tone volume of a musical tone and 
the waveform of a musical-tone envelope on the basis of the above tone 
volume data and the vibration durations t1 to t3 of respective divided 
portions of the sound plate 11. 
Effect control data for echo effect, reverberation effect and the like are 
set when the peak value Pi of a certain divided portion of the sound plate 
11 exceeds a predetermined value. 
The tone pitch data, timbre data, envelope control data and effect control 
data set in the above-mentioned manner are output from the control circuit 
1 to the sound source circuit 4. 
The sound source circuit 4 generates a musical tone designated by the above 
timbre data, tone pitch data and envelope control data, to which musical 
tone the effect designated by the above effect control data and supplies 
the musical tone to the sound system 6. The sound system 6 outputs sound 
of the musical tone generated by the sound source circuit 4. 
The tone volume of the musical tone varies in accordance with the 
percussion intensity to the sound plate 11. Therefore, the percussion 
intensity of the mallet 20 can delicately change the tone volume of the 
musical tone. The selection of the striking position on the sound plate 11 
can apply effects such as echo effect, reverberation effect and the like 
to the musical tone. 
When a body other than the sound plate 11 is struck with the mallet 20, the 
peak values P4 and P5 of the vibration of the mallet portion 21 are input 
through the peak detection circuit 35 to the control circuit 1. The 
vibration durations t4 and t5 of the mallet portion 21 are also input 
through the vibration-duration detection circuit 36 to the control circuit 
1. In this case, the control circuit 1 sets a certain rhythm sound on the 
basis of the operation data of the timbre selection switches 61 to 63 
provided on the struck mallet 20 and also sets tone volume data of the 
above rhythm sound on the basis of the peak values P4 and P5. Further, the 
control circuit 1 sets the envelope control data on the basis of the above 
vibration duration t4 and t5 and the above tone volume data. 
The above rhythm sound data and envelope data are supplied from the control 
circuit 1 to the sound source circuit 4. The sound source circuit 4 
generates the rhythm sound to output the same through the sound system 6. 
In this manner, a rhythm performance can be executed with certain rhythm 
sounds, when a body other than the sound plate 11 is struck with the 
mallet 20. 
Second Embodiment 
In the above first embodiment, the peak values P1, P2 and P3 corresponding 
to respective percussion intensities to the divided portions of the sound 
plate 11 are used for controlling the tone volume. But, different kinds of 
timbres in the same family are assigned to the divided portions of the 
sound plate and three kinds of timbres can be composed at the ratio of the 
peak values P1, P2 and P3 to produce another timbre. 
More specifically, in case that for example, piano sound is selected by 
operation of the timbre selection switches 61 to 63 on the mallet 20, 
timbres in the piano sound family such as piano sound A, piano sound B and 
piano sound C are assigned to the respective divided portion of the sound 
plate 11. Then, timbres of the above piano sounds A, B and C are composed 
at the ratio of the peak values P1, P2 and P3, each corresponding to the 
percussion intensity to each divided portion of the sound plate 11. In 
this way, an abundant performance with delicate timbres can be obtained 
when the sound plate 11 is struck on different positions and with 
different striking intensities with the mallet 20. 
FIG. 10 is a view showing one construction of the sound source circuit used 
in the second embodiment. In FIG. 10, circuits 200a, 200b and 200c are the 
same circuit as the sound source circuit 4 surrounded with a broken line 
in FIG. 4. 
The sound source circuit 200a has a waveform memory 44a for storing timbres 
of a piano, pipeorgan, drum and so on in a family A. The sound source 
circuit 200b also has a waveform memory 44b for storing timbres of a 
piano, pipeorgan, drum and so on in a family B. Similarly, the sound 
source circuit 200c has a waveform memory 44c for storing timbres of a 
piano, pipeorgan, drum and so on in a family C. 
When the same timbre data and the same tone pitch data are supplied to the 
sound source circuits 200a, 200b and 200c, waveforms of designated timbres 
of families A, B and C are read out from the waveform memories 44a, 44b 
and 44c of the sound source circuits 200a, 200b and 200c. 
The peak values P1, P2 and P3 are supplied as envelope control data to the 
envelope generators 46a, 46b and 46c of the sound source circuits 200a, 
200b and 200c. Then the envelope generators 46a, 46b and 46c generate 
amplitude envelope data proportional to the peak values P1, P2 and P3 and 
supply these data to the relevant digital amplifiers 45. 
Therefore, the amplitude envelopes of waveforms A, B and C output from the 
sound source circuits 200i a, 200b and 200c will be at the ratio of the 
peak values P1, P2 and P3. The waveforms A, B and C are added by an adder 
201 and then a digital-signal processing circuit 47 applies various 
effects such as echo effect, reverberation effect and the like to the 
added waveform. The added waveform is transferred to a D/A converter 48. 
The D/A converter 48 converts the added waveform to an analog musical-tone 
signal. 
Third Embodiment 
FIG. 11 is a view illustrating a system construction of the third 
embodiment applied to an electronic percussion instrument. Note that, as 
not shown, the same circuits as the sound source circuits 4a and 4b for 
the left hand mallet and the right hand mallet, the mixing circuit 100 and 
the sound system 6 in FIG. 1 are provided in the third embodiment. 
In the third embodiment, operation signals SL and SR of switches provided 
on the mallet 20L (20R) and a left ON-signal (a right ON-signal) 
indicating the presence of the percussion operation by the mallet 20L 
(20R) (which ON-signal is detected by a level detection circuit 110) are 
frequency-modulated and transmitted by an FM radio wave transmitting 
circuit 101 provided in the mallet 20L (20R). The FM radio wave is 
received and demodulated by an FM radio wave receiving circuit 102 
provided in a body GH of the musical instrument. Then, the demodulated 
signal is delivered to the control circuit 1. 
The above operation signals SL and SR and ON-signal input to the control 
circuit 1 are used to control parameters of a musical tone to be 
generated. These signals are also stored in the sequencer RAM 7. 
In this manner, various signals indicating the presence of the percussion 
operation by the mallet 20L (20R), timbre, effects and the like can be 
transmitted from the mallet 20L (20R) to the body GH of the musical 
instrument by means of the FM radio communication. Therefore, a cord for 
connecting the mallet 20L (20R) to the body GH of the musical instrument 
is not required. As a result, a player is allowed to play the musical 
instrument feeling at ease without paying any attention to the connecting 
cord. 
Other Embodiment 
It will be easily understood by those skilled in the art that the effects 
to be applied to musical tones are not limited to those described in the 
above embodiment, but other various effects such as vibrato effect, phase 
shift effect and the like may be applied to musical tones. 
The number of switches provided on the mallet is not limited to three units 
but other switches in addition to above switches can be installed on the 
mallet. 
Further, in the above embodiment, the pressure sensor element is used for 
sensing the percussion operation by the mallet as a striking member, but 
conductive gum can be used for sensing a percussion operation, impedance 
of which varies with contraction caused when the gum is struck. 
Furthermore, in the above embodiment, the FM radio wave transmitting 
circuit 101 is prepared outside the mallet 20L (20R), but the FM radio 
wave transmitting circuit can be mounted in the mallet body 20L (20R).