Touch-response tone controller unit for an electronic musical instrument

In construction of an electronic musical instrument having plural musical tone controllers such as keys, push buttons and an expression pedal unit, a number of pulses are generated depending on the extent of movement of each controller on output lines whose number is smaller than that of the pulses so generated and musical tone control parameters such as tone volume, tone color and tonal pitch are changed in multi-stage fashion in response to the pulses generated. Generation of musical tones is assured whilst well reflecting delicate change in player's emotion via subtle key touch control.

BACKGROUND OF THE INVENTION 
The present invention relates to an electronic musical instrument, and more 
particularly relates to improvements in control of musical tone generation 
in response to controller operation on an electronic organ, an electronic 
piano or a portable electronic musical instrument, and the like. 
In this specification, the term "a controller" refers to not only a white 
or black key but also a push botton key, a foot plate of an expression 
pedal mechanism, a knee lever, a joy stick operator on an electronic 
musical instrument. Further the term "musical tone control parameter" 
refers to all sorts of musical tone control parameters such as tone 
volume, tone colour, tonal pitch, tempo, depth and speed of vibrato and 
tremolo, etc. 
Control of tone generation in an electronic musical instrument such an 
electronic organ is basically carried out by manual key operation which 
controls the state of an associated key switch. This mode of control, 
however, is too simple in tone generation characteristics to correctly 
reflect delicate changes in a player's feelings. 
In an attempt to make up for this demerit in tone generation 
characteristics, it was already proposed to provide an electronic musical 
instrument with a so-called touch-response function which varies tone 
generation characteristics on the basis of the magnitude of key operation 
for richer reflection fo player's feelings. In accordance with this 
touch-response funcetion, the tone volume, the tonal pitch and the tone 
colour of a musical tone are controller in accordance with player's finger 
motion during the rise and decay periods of the musical tone. 
In the case of a touch-response type control system proposed in U.S. Pat. 
No. 3,705,254, a relative displacement between a magnet and a coil is 
caused by key operation to generate a induced electromotive force output 
which is used to control the response to key touch. In this case, signal 
processing in analog mode requires a complicated hardware construction 
and, consequently, increased production cost. In addition, no stability in 
operation can be much expected. 
Another touch-response type control system is disclosed in U.S. Pat. No. 
4,079,651 in which an electrically conductive and elastic piece is 
deformed in response to key operation and such deformation establishes 
sequential short circuits between fixed contacts arranged on a substrate 
to change the resistance stepwise. Such change in resistance is converted 
into voltage output which is used to control the response to key touch. 
Also in this case singal processing is carried out in analog mode, which 
requires a complicated hardware construction and high production cost. In 
addition, it is rather infeasible to leave a too small pitch between 
adjacent fixed contacts from the view points of contact formation and 
circuit wiring. For these reasons, no subtle control of touch-response can 
be expected in the case of this prior proposal. 
A further touch-response type control system is proposed in Japanese Patent 
Application Laid-Open Sho. 58-18812 in which a disc type mobile contact is 
driven for rotation by key operation. Following the rotation, the mobile 
contact is brought into sequential contact with a plurality of fixed 
contacts arranged on the substrate to generate digital signal outputs 
which are used for control of tone generation. This type of control system 
is well suite for an electronic musical instrument which generates musical 
tones by means of digital signal processing by a mirco computer recently 
in fashion. In this case also, subtleness in signal generation is much 
degraded by difficulty in contact arrangement. In addition, the number of 
output lines is directly affected by that of the contacts used in the 
system, thereby commplicating the construction and increasing the 
production cost. 
SUMMARY OF THE INVENTION 
It is the object of the present invention to provide an electronic musical 
instrument of a simple construction and low production cost which, 
nevertheless, assures subtle touch-response control of tone generation. 
In accordance with the basic concept of the present invention, a number of 
pulses are generated corresponding to the extend of movement of a musical 
tone controller on output lines whose number is by far smaller than that 
of theh pulses and, in correspondence to the number of the pulses so 
generated, musical tone control parameters are chaned in a multistage 
fashion. The tone control parameters include tone volume, tone pitch, tone 
color, and various effects, further include touch feeling control and 
image control parameters, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As stated above, the electronic musical instrument of the present invention 
is comprised of, as the major elements, means for genrating a number of 
pulses and means for changing musical tone control parameters. 
The first embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 1 to 6 in which the 
instrument includes the first example of the pulse generating means. In 
the arrangement, a key 1 made of, for example, synthetic resin is provided 
with projecting sections 1b and 1c formed on the bottom face near its 
operating section 1a. An additional projecting section 1d is formed on the 
bottom face about the middle of its length. A engaging section 1e is 
formed on one end remote from the operating section 1a. The projecting 
section 1c is accompanied with a stopper section 1f for limiting the 
upward swing of the key 1. 
Although a white key 1 is shown in the drawing, black key 1' is provided 
with a substantially same construction with an only exception that the 
operating section projects somewhat upwards. 
The key 1 is supported by a frame 2 made of a magnetic material such as 
iron and its through holes 2a and 2b receive the engaging section 1e and 
the stopper section 1f of the key 1, respectively. A clip-type leaf spring 
3 clamps a rear rise 2c of the frame 2 to allow pivotal movement of the 
key 1 about a support C on the frame 2, and the key 1 can't be separated 
from the frame 2. 
Another leaf spring 4 is interposed between the key 1 and the frame 2 so as 
to bias the operating section 1a of the key 1 upwards. The extent of the 
upward bias of the operating section is limited by contact of the stopper 
section 1f of the key 1 with a stopper 5 attached to the bottom face of 
the frame 2. The stopper 5 is generally made of felt. 
A lower step 2d formed at the front end of the frame 2 carries a stopper 6 
for contact with the projecting section 1f of the key at key operation. 
This stopper 6 is also generally made of felt. Near the stopper 6, the 
lower step 2d further carries a rise 7 made of a magnetic material such as 
iron facing each key 1. The rise 7 is screw fixed to each projecting 
section 1c of the key 1 whilst leaving a small gap in between to form a 
common rear yoke. 
The projecting section 1c is accompanied on its rear face with a laminated 
magnet 8. This laminated magnet 8 is made up of a plurality of unit 
magnets superimposed with each other, alternating the positioning of their 
N and S poles. The laminated magnet 8 is attached to the projecting 
section 1c at its one magnetic pole face and the other pole face 8a 
extends along a plane defined by an imaginary arc having its center on the 
support C on the frame 2. More specifically, its N poles project from the 
plane and its S poles recede from the plane. 
The above-described contruction forms means for inducing magnetic change. 
As shown in FIG. 3, a print board 9 is mounted to the top face of the frame 
2 and is provided with slits 9a which extend in the longitudinal direction 
of the key 1 in parallel to each other at a pitch equal to that between 
adjacent keys 1. A coil 10 is formed surrounding each slit 9a by means of 
printing process. One end of the printed coils 10 in a same octave are 
grouped for common connection to a connecting terminal 11 whereas the 
other end of the coils 10 in a same octave are also grouped and earthed 
together. 
An iron yoke 13 is placed on the print board 9 via an adhesive insulating 
sheet 12 and its bent section 13a is brought into contact with the top 
face of the frame 2 whilst passing through the associated slit 9a (See 
FIG. 4). The other end of the yoke 13 faces the pole face 8a of the 
laminated magnet 8 with a slight gap in between. In this arrangement, a 
cover 14 made of a non-magnetic material is fixed to the yoke 13 via a 
screw 15 (in FIG. 1) in order to fix the position of the yoke 13 and to 
press its bent section 13a against the frame 2. 
The above-described construction forms means for detecting magnetic change. 
A slope 13b is preferably made at the other end of the yoke 13 for reduced 
magnetic flux loss. As a substitute for the pressure contact of the bent 
section 13a with the frame 2, a flat yoke 13' such as shown in FIG. 5 may 
be used in combination with the frame 2 having a bent section 2e for tight 
contact with the yoke 13'. A penetrating photosensor 16 may be arranged on 
the print board 9 facing the projecting section 1d of the key 1 so that 
the projecting section 1d should intercept a beam issued by the 
photosensor 16 for detection of the state of the key 1. 
The above-described first embodiment of the present invention operates as 
follows. In FIGS. 1 and 3, a closed magnetic circuit is formed by the 
laminated magnet 8 including the yoke 13, the frame 2 and the rise 7. When 
the operating section 1a of the key 1 is depressed against repulsion by 
the leaf spring 4, the laminated magnet 8 moves downwards along an arc 
having its center on the support C. During this movement, the direction of 
line of magnetic force is reversed when the N or S pole of the magnet 8 
mates the yoke 13, thereby causing abrupt changes in magnetic flux in the 
above-described closed magnetic circuit. As a result, induced current in 
pulse mode flows through the coil 10 formed around the yoke 13 in 
alternate directions and a number of pulses are generated in non-contact 
mode in correspondence to the extent of movement of the key 1, the 
controller. The number of the pulses generated within a unit time is 
proportional to the depression speed of the key 1. So, by changing the 
above-described musical tone control parameters in multistage fashion, 
musical tones can be generated exactly as intended by the player while 
subtly reflecting delicate changes in player's feelings. 
For issue of the pulse signals by the above-described arrangement, it is 
needed to prepare one common earth line for all the keys and one signal 
line for each key only. 
Various examples of the laminated magnet 8 are shown in FIGS. 6A to 6D. In 
the case of the laminated magnet 8 shown in FIG. 6A, its pole face 8a is 
defined by an arc having its center on the support C on the frame 2 and 
the N and S poles are superimposed up and down. With this arrangement, the 
induced current appearing on the coil 10 varies softly. The N and S poles 
of this type can be formed by magnetization of even a micron order pitch. 
In the arrangement shown in FIG. 6B, the N poles project from the arc 
plane and the S poles recede from the arc plane. Since the induced current 
appearing on the coil 10 in this case includes sharp rises and falls, this 
arrangement is quite suited for generation of high peak pulses. The magnet 
8 shown in FIG. 6C is same in configuration as the one shown in FIG. 6B 
but its N (or S) pole is positioned on the yoke side face and its S (or N) 
pole is positioned on the opposite face. In the case of these three 
examples, same pulses are generated during the go- and return-movement of 
the key 1. As a consequence, when it is required to utilize the pulse 
generated during the go-movement only, some additional means must be 
provided to discriminate the direction of the key movement or some 
complicated signal processing must be employed. This inconvenience can be 
tactfully obviated in the case of the arrangement shown in FIG. 6D in 
which the pole face of the magnet 8 has a saw tooth configuration. When 
the key is depressed with this arrangement, its positive rise pulse is 
made large and its negative rise pulse is made small. Whereas, when the 
key returns from the depression, its positive rise pulse is made small and 
its negative rise pulse is made large. As a consequence, by setting a 
threshold level higher than the positive rise pulse during return from 
depression, only the pulses generated during key depression can be easily 
selected. 
The second embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 7 and 8 in which pulses are 
generated in a photoelectric manner. In the case of this embodiment, 
supporting webs 21a are formed on the bottom face of a key 21 whilst 
projecting downwards and a pattern plate 22 is mounted to the supporting 
webs 21a whilst extending in the longitudinal direction of the key 1. As 
shown in FIG. 8, the pattern plate 22 includes opaque horizontal stripe 
patterns 22a formed on a transparent film at fine intervals. These 
elements form optical change inducing means. 
A print board 23 is arranged on the frame 2 facing the bottom face of the 
key 21 and slit 2f for the supporting webs 21a and a slit 23a for the 
pattern plate 22 are formed through the print board 23 and the frame 2. 
These slits 2f and 23a are connected to each other to form an H-shaped 
continuous opening. A light emitter 24a and a light collector 24b are 
arranged sandwiching the slit 23a for the pattern plate 22 to form a 
penetrating type photosensor 24. These elements form means for detecting 
optical change. 
As the key 21 is depressed, the pattern plate 22 passes through the gap 
between the light emitter 24a and the light receiver 24b so that the light 
beam between them is temporarily intercepted by the horizontal patterns 
22a and such interception causes a change in pulse mode of the current 
flowing in the light receiver 24b. Thus a nunber of pulses are generated 
in non-contact fashion in correspondence to the extent of movement of the 
key 21. 
The third embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 9 to 12 in which pulses are 
again generated in a photoelectric manner. A cavitious projection 31a is 
formed on the bottom face of a key 31 to operate as a stopper for movement 
of the key 31. The rear face 31b of the projection 31a is defined by an 
imaginary circle having its center of the support C. A pattern plate 32 
including horizontal stripe patterns at fine intervals as shown in FIG. 11 
is bonded to the rear face 31b of the projection 31a to provide a pattern 
face 32a. Alternatively, horizontal patterns may be directly applied to 
the rear face 31b of the projection. These elements form the optical 
change inducing means. Facing the pattern face 32a on the key 31, a 
reflecting type photosensor 34 is arranged on a print board 33 mounted to 
the top face of the frame in order to form the optical change detecting 
means. 
One example of the reflecting type photosensor 34 is shown in detail in 
FIGS. 12A to 12C. The photosensor 34 is made up of a light emitter 34A and 
a light collector 34B. The light emitter 34A includes a light emitting 
element 34a such as a light emitting diode, a pair of condenser lenses 34b 
and 34c and a reflecting plane 34d. Whereas the light collector 34B 
includes a light collecting element 34e such as a photodiode or a 
phototransistor, a light collecting lens 34f and a reflecting plane 34h. 
Light beams issued by the light emitter 34A are made parallel to each other 
by the condenser lens 34b and, after changing their course of travel over 
90 degrees at the reflecting plane 34d, are collected onto the pattern 
face 32a by operation of the condenser lens 34c. Light beams reflected at 
the pattern face 32a are made parallel to each other after passage through 
the collecting lens 34g and, after changing their course of travel over 90 
degrees at the reflecting plane 34h, are collected onto the collecting 
element 34e by operation of the collecting lens 34f. 
As the pattern face 32a swings downwards on depression of the key 31, the 
light collector 34B intermittently collects light from the light emitter 
34A to practice photoelectric conversion, thereby generating a number of 
electric pulses in correspondence with changes in intensity of the light 
so collected. 
Here, the cavity 31c in the projection 31a is a sort of asylum for the 
photosensor 34 which allows smooth rearward sliding of the key 31 at 
mounting to the frame 2. 
The fourth embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 13 to 24 in which key 
movement is mechanically amplified in order to provide the so-called piano 
tough even on an electronic musical instrument. A key 41 is provided at 
the proximal end with a recess 41a which is in pivotal engagement with a 
pin 43 fixed to the rear end of a slit 42a formed in a frame 42. Another 
pin 44 is fixed to the front end of the slit 42a in pivotal engagement 
with a recess 45a formed in the proximal end of a hammer 45 made of a 
massy material such as iron. This hammer 45 is driven for an amplified 
movement when the key 41 is operated. A leaf spring 46 is fixed at its 
proximal end to the pin 43 and its free distal end is placed in engagement 
with a rear step 45b formed on the hammer 45. By this spring force the 
hammer 45 is urged to turn clockwise in FIG. 14. 
The hammer 45 is provided with a presser 45c for engagement with a recess 
45b formed in the bottom face of the key 41 so that the hammer 45 should 
move downwards against repulsion by the leaf spring 46 when the key is 
depressed. There is a big difference between the distance of the presser 
45c from the pin 43 for the key 41 and the distance of the presser 45c 
from the pin 44 for the hammer 45. More specifically, the distance of the 
presser 45c from the hammer pin 44 is smaller than that of the presser 45c 
from the key pin 43. As a consequence, movement of the key 41 is greatly 
amplified due to this difference in distance to cause a corresponding 
movement of the hammer 45. Thus, the so-called piano touch is obtained by 
this amplification even on an electronic musical instrument. 
The hammer 45 is provided on its lower side face with a magnet pattern 45d 
such as shown in FIG. 15A. This magnet pattern 45d includes a plurality of 
N- and S-poles which are magnetized at alternate positions in an imaginary 
sector having its center on the hammer pin 44. A resin block 47 such as 
shown in FIG. 16 is fixed to the bottom face of the frame 42 having 
juxtaposed narrow interstices 47a so that the magnet pattern 45d of each 
hammer 45, i.e. each key 41, should be idly received in an associated 
interstice 47a. 
At moulding of the resin block 47 a flexible substrate 48 including a 
plurality of conductive patterns 48a such as shown in FIG. 17 is placed in 
a mould with the conductive patterns 48a being folded as shown in FIG. 18 
before injection of resin. The conductive patterns 48a are arranged on 
walls 47b to 47d of the molded resin block 47 surrounding the interstices 
47a. In this case, the conductive pattern 48a between the walls 47b and 
47d should be arranged so as to meet the radial direction from the pin 44 
on the frame 42. 
Briefly speaking, the hammer 45 is prepared as follows. In the first place 
a distal piece 45e, a middle piece 45f and a proximal piece 45g made of 
iron are prepared. Except for faces for bonding, cutouts 45h are formed on 
the edges of, for example as shown in FIG. 20, the middle piece 45f. After 
magnetization of the both faces of the middle piece 45f, the cutouts 45h 
are covered with resin films 45i. The distal and proximal pieces 45e and 
45g are prepared in a same manner and they are combined together to form a 
monolithic hammer 45 as shown in FIG. 19. Addition of such resin films 
prevents undesirable contact of rough edges of the hammer 45 with the 
inner faces of the resin block 47. Here, the thinner the resin films, the 
larger the magnetic change. The better way recommended is to smooth the 
edges of the hammer 45 without covering with such resin films. 
A strong electromagnet such as shown in FIG. 21 is used for magnetization 
of the middle piece 45f of the hammer 45. Partial magnetization of one 
face is carried out during relative intermittent movement between the 
electromagnet and the middle piece 45f at prescribed intervals. After 
complete magnetization of one face, the other face is magnetized in same 
manner. For stronger magnetization, it is preferable to magnetize the 
other face in a reversed order of poles as shown in FIG. 15B. In this way, 
the conductive patterns 48a on the walls 47b and 47d are phased from each 
other by a distance equal to one pitch of the magnet pattern 45d formed on 
the hammer 45. Both faces of the middle piece 45f may be magnetized 
concurrently too. 
As the key swings downwards about the pin 43 at key depression, the hammer 
45 also swings downwards about the pin 44 at a speed faster than the key 
41 and its magnet pattern 45 passes by the region of the conductive 
pattern 48a on the resin block 47 and corresponding current flows through 
the conductive pattern 48a. 
The principle of this electric conduction will be explained in reference to 
FIG. 22. With the illustrated arrangement of the magnetic pattern 45d, the 
current flows through the conductive pattern 48a in the direction of an 
arrow Y or Y'. As the magnet pattern 45d moves in the direction of an 
arrow X over one pitch, the direction of the magnetic field is reversed 
and the flowing direction of the current is also reversed. This change in 
flowing direction of the current produced pulses of opposite polarities. 
The conductive pattern 48a is continously folded in a hairpin mode at 
sections extending normal to the moving directions of the magnet pattern 
45d in order to provide a long pattern within a limited space, thereby 
generating large pulses. 
When the length of the conductive pattern 48a is equal to .iota., the 
moving speed of the magnet pattern 48a is equal to v and the magnetic flux 
density is equal to B, the induced electromotive force (E) is given by the 
following equation; 
EQU E=vB.iota. 
It is clear from this equation that increase in length of the conductive 
pattern 48a brings about enlarged electromotive force. 
One example of the pulse signal so generated is shown in FIG. 15C. This 
pattern of pulse signal is resulted from the fact that, as shown in FIG. 
15E, highly magnetized sections A20 exist at the borders between N- and 
S-poles and lowly magnetized sections A21 are made between the borders 
naturally. By properly adjusting the mode of magnetization, a sine wave 
pulse signal can be obtained too. 
It should be noted that the pulse generating means of this embodiment can 
be used in a keyboard type electronic musical instrument without hammer 
too by arranging the magnet pattern the side face of a member attached to 
a key. 
In the case of the above-described embodiment, the number of pulses 
generated is in inverse proportion to the pitch of the magnet pattern 45d 
formed on the hammer 45. In other words, the smaller the pitch of the 
magnet pattern, the larger the number of the pulses. From the view point 
of magnetic flux density, however, its sometimes difficult to employ a too 
small pitch in design of the magnet pattern 45d. This conflicting problem 
can be solved by properly adjusting the pattern of the conductive pattern 
48a. 
One example of such a conductive pattern is shown in FIG. 23. On one side 
of the conductive pattern 48c, the pitch of the pattern is phased in the 
central section over 1/2 of the pitch of the magnet pattern 45d. By 
phasing the pattern over 1/2 pitch in the direction of an arrow X in FIG. 
23, the change in pitch of the magnetic field is made one-half in the 
section extending normal to the arrow X so that a double number of pulses 
should be generated per same extent of movement of the magnet pattern 45d 
as shown in FIG. 15D. As an alternative, the magnet pattern on the hammer 
45 may be phased in the central section over 1/2 of the pitch of the 
conductive pattern in the direction of the arrow X in FIG. 24. 
The fifth embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 25 to 29 in which pulses are 
generated in a photoelectric manner in response to movement of a hammer. 
In FIG. 25, a hammer 51 is mounted to the frame 42 in a manner 
substantially same as the hammer 45 in the foregoing embodiment. A convex 
arc face 51a is formed at the distal end of the hammer 51 with its center 
falling on the pin 44 for the hammer and a pattern place 52 is bonded to 
the arc faces 51a. This pattern plate 52 is provided with a horizontal 
stripe pattern 52a such as shown in FIG. 26A to form a pattern face 52b. 
As an alternative, the stripe pattern 52a may be applied directly to the 
arc face 51a too. 
A stand 42b having a concave arc face 42c is mounted to the frame 42 whilst 
facing the pattern face with a slight gap and a reflecting type 
photosensor 53 is arranged on the arc face 42c as shown in FIG. 26B. This 
photosensor 53 is made up of a light emitting element 53a and a light 
collecting element 53b as shown in FIG. 27 and connected to a power source 
not shown by means of a conductor running through a slit 42d formed in the 
arc face 42c so that light beams issued by the light emitting element 53a 
is reflected at the pattern face 52b to reach the light collecting element 
53b. 
With this arrangement, as the key 51 swings downwards, the pattern face 52b 
also swings downwards about the pin 44. The light collecting element 53b 
then collects light from the pattern face 52b intermittently so as to 
generate a number of pulses after photoelectric conversion of the light. 
Further in FIG. 28, a slit 42c for passage of the hammer 51 is formed in a 
print board 54 bonded to the frame 42 and the slit 42c is surrounded by a 
coil 54a. As shown in FIG. 25, a magnet pattern 55 is provided at a 
position just before the upper limit of the hammer movement where the 
hammer 51 passes by the coil 54. With this arrangement, a pulse signal can 
be generated by the coil 54a just before complete return of the key 41 to 
its initial position. 
Further, magnetic patterns same as the one 45d shown in FIG. 15A are 
applied to both sides of the hammers 51 part passing through the slit 42c 
over the entire stroke of the hammer movement. In this case, movement of 
the hammer 51 caused by key depression generates AC current in the coil 
54a which can be used to energize the photosensor 53 after proper 
rectification. In this way, photoelectric pulse generation can be carried 
out without any power supply from outside the system. 
In FIG. 29, a metallic plate 55 made of iron or aluminum is bonded to the 
inner wall of the front end 51a of the key 41 and a print board 56 is 
fixed to front rise of the frame 42. A coil 57 is printed on the print 
board 56 facing the metallic plate 55. With this arrangement, movement of 
the metallic plate 55 on key depression causes a change in magnetic flux, 
thereby causing a corresponding change in current flowing through the coil 
57. The coil 57 is connected to a detection circuit 58 which detects such 
a change in current that is, key-on state and key-off state can be 
distinguished and issues a key off signal KOFF during return movement of 
the key 41. 
In the case of this embodiment without such system as FIG. 29 described 
above, same signals are generated from the photosensor 53 during the go- 
and return-movement of the key, which cannot be discriminated. A solution 
to this problem is shown in FIG. 30 in which the stripe pattern formed on 
the arc face of the hammer 51 is made up of a pair of patterns 52A and 52B 
which are phased from each other by 1/2 pitch and a pair of photosensors 
53A and 53B are arranged at a same level in both of the patterns 52A and 
52B. With this arrangement, the outputs from the photosensors 52A and 52B 
during the go-movement of the hammer 51 are shown in FIG. 31A. In this 
case, the output A is ahead of the output B by a phase equal to .pi./2. 
The outputs during the return-movement of the hammer 51 are shown in FIG. 
31B in which the output B is ahead of the output A by a phase equal to 
.pi./2. The direction of the movement of the hammer 51 is discriminated on 
the basis of such a mode of phase lag. As a substitute for the phase in 
horizontal stripe, the pair of photosensors 52A and 52B may be phased by 
half of the pattern pitch. 
It should be noted that this solution is applicable to the first to fourth 
embodiments also. When the pulse generating means includes a magnet, a 
coil and a yoke, the magnet pattern may be divided into a pair of patterns 
of 1/2 phase lag and a pair of yokes each with the coil may be arranged in 
combination with such a pair of divided magnet patterns. In an 
alternative, a pair of yokes may be arranged with 1/2 pitch phase lag. 
The sixth embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 32 to 34 in which the 
instrument has a portable design suited to be held by hand. This 
instrument includes a prism type hand piece 60 provided on its top face 
60a with four push buttons 61 and on its side face 60b with one push 
button 61. The push buttons 61 on the top face 60a are for operation by 
the index, middle, ring and little fingers whereas the push button 61 on 
the side face 60b is for operation by the thumb of a player. Depression of 
the push buttons 61 causes generation of musical tones of different tonal 
pitches. So by holding a pair of instruments of this type of different 
tone ranges in two hands, the player can carry out performances of various 
modes. 
The construction associated with each push button 61 is shown in detail in 
FIG. 33 in which the push button 61 is accompanied at the bottom with a 
cylindrical laminated magnet 62 having N- and S-poles superimposed in an 
alternating fashion as shown in FIG. 34. The laminated magnet 62 is 
accommodated in an axial blind bore formed in a resin casing 63 embedded 
in the hand piece 60 and urged to move upwards by a compression spring 64 
interposed between the bottom of the laminated magnet 62 and the bottom 
wall of the resin casing 63 so that the head of the push button 61 should 
always project outside the bore in the resin casing 63. A ring coil 65 is 
circumferentially embedded in the wall of the bore in the resin casing 63 
at about the middle of its depth and a cushion 66 is bonded to the bottom 
of the bore. A conical depression 63a is formed in the top face of the 
resin casing 63 in order to give a long stroke for depression of the push 
button 61. 
When the push button 61 is depressed against repulsion by the compression 
spring 64, the laminated magnet 62 moves downwards to cause a change in 
magnetic fluxes around the ring coil 65. This change in magnetic fluxes 
induces alternate flows of current in opposite directions in the ring coil 
65, thereby generating pulses of different polarities. 
This construction can be generally applied to various electronic musical 
instruments. For example, each key of an electronic musical instrument may 
be operationally coupled to a member corresponding to the push button 61 
used in this embodiment. 
Another example of the push button type, i.e. the seventh embodiment of the 
electronic musical instrument in accordance with the present invention is 
shown in FIGS. 35A to 37 in which a push button 71 is provided with a 
center bank 73 projecting downwards from its bottom face. This center bank 
73 is sandwiched by a pair of magnet plates 72 each including N- and 
S-poles magnetized at alternating positions. A print board 74 mounted to 
the frame is provided with slits 74a for passage of the push button 71. 
Each slit 74a is surrounded on both faces of the print board 74 by coils 
75. The coils 75 are firmly held on the print board 74 by a pair of yokes 
77 via insulating layers 76 and each yoke 77 has slits 77a at positions 
corresponding to the slits 74a in the print board 74. 
On depression of a push button 71, an associated pair of magnet plates 72 
penetrates the slit 74a in the print board 74 passing by the positions of 
the coils 75 and a corresponding change in magnetic fluxes causes flow of 
induced current in the coils 75, thereby generating a number of pulses. 
During this process, concentration of magnetic fluxes takes place at edges 
of the yokes 77 to increase the pulse current flowing through the coils 
75. This embodiment can be applied for an usual electronic musical 
instrument, too. 
The eighth embodiment of the electronic musical instrument in accordance 
with the present invention is shown in FIGS. 38 to 41 in which pulses are 
generated in a photoelectric manner in response to key movement on the 
basis of the Moire stripe principle. A heavy magnet block 82 is fixed to 
the bottom face of a key 81 and a pair of frames 82 and 83 are fixed to a 
frame not shown whilst being spaced from each other in the longitudinal 
direction of the key 81. 
One frame 83 is provided with a pair of vertical grooves 83a and 83b spaced 
from each other in the width direction of the key 81 and one groove 83a 
idly receives a slide frame 84a of a slide unit 84 which is provided at 
its top with a magnet 84b in magnetic contact with the overhead magnetic 
block 82. For this contact, the magnet 84b is provided with a round top 
face such as shown in FIG. 38 or a cylindrical top face such as shown in 
FIG. 39. The other groove 83b receives a fixed pattern plate 85 which is 
provided with a stripe pattern 85a including transparent and opaque 
sections at alternating positions with a pitch P as shown in FIG. 40. In 
correspondence with this, the slide unit 84 is provided with a mobile 
pattern plate 87 fixed to its slide frame 84a. The mobile pattern plate 87 
is provided with a stripe pattern 87 which has transparent and opaque 
sections at alternating positions with a pitch same as that of the stripe 
pattern 85a on the fixed pattern plate 85 but with a small inclination 
with respect thereto. Preferably, the fixed and mobile pattern plates 85 
and 87 are arranged with their mating faces as close as possible. For 
example, the intervening distance D.sub.11 should be equal to 0. On 
different sides of the fixed and mobile pattern plates 85 and 87 are 
arranged a light emitting element 88a and a light collecting element 88b 
of a penetrating type photosensor 88. Alternatively, a reflecting type 
photosensor may be used with its light emitting and collecting elements 
arranged on a same side of the fixed and mobile pattern plates 85 and 87. 
As the key 81 is depressed, the magnetic block 82 moves downwards to urge 
the slide unit 84 downwards. Presence of a curved plane at the top of the 
magnet 84b ensures smooth linear movement of the slide unit 84 along the 
groove 83b in the frame 83 despite the swing movement of the magnetic 
block 82 caused by the key movement. Due to the lowering of the slide unit 
84, its mobile pattern plate 87 overlaps the fixed pattern plate 85 on the 
frame 83 to produce vertical Moire stripes 89 such as shown in FIG. 41, 
which move in a horizontal direction in accordance with the movement of 
the mobile pattern plate 87. On return movement of the key 81, the mobile 
pattern plate 87 automatically resumes the position shown in FIG. 38 due 
to magnetic attraction between the magnet 84b and the magnetic block 82. 
It is known that the following relationship exist in production of a Moire 
pattern. 
EQU W=P/2 sin (.theta./2) (1) 
W; the interval of the Moire pattern 89 
P; the pitch of the stripe patterns 85a and 87a 
.theta.; the angle of inclination in radians between the stripe patterns 
85a and 87a 
When the angle of inclination (.theta.) is sufficiently small, the 
following approximation can be employed. 
EQU W=P/.theta. (2) 
By this method a slight movement of the mobile pattern plate 87 brings 
about a rapid movement of the Moire stripe 89. That is, a slight key 
movement can produce a great number of Moire stripes. When the pitch P of 
the stripe patterns 85a and 87a is equal to 0.1 mm, a key movement of 10 
mm stroke can produce 100 stripe crossings. Detection of such stripe 
crossings by the photosensor generates a great number of pulses. 
The angle of inclination of the stripe patterns 85a and 87a is preferably 
chosen so that the interval of the resultant Moire stripe should be larger 
than the degree of resolution of the photosensor. In an alternative 
example, a magnet may be attached to the key 81 and the slide unit 84 may 
be made of a magnetic substance. 
In one modification of the instrument based on the Moire stripe principle 
shown in FIG. 42, pattern plates 85b and 87b are attached to mobile and 
fixed pattern frames 84c and 86a defined by imaginary cylindrical planes 
having their centers on a support C that is, the fixed pattern frame 84c 
is fixed to a part of the key or the hammer. With this arrangement of the 
fixed and mobile stripe patterns, the angles both of stripe patterns are 
small during the starting period but rendered large during the terminal 
period of key depression. As a consequence, the Moire stripe is small in 
number during the starting period and large during the terminal period, 
thereby assuring generation of lots of pulses per a small extent of key 
movement in after touch control. 
The effects accruing from employment of the above-described Moire stripe 
principle will now be explained in more detail in reference to FIGS. 38 
and 41 to 44. In the condition that the fixed and mobile pattern plates 85 
and 87 overlap as shown in FIG. 38, the illustration in FIG. 41 is 
magnified in FIGS. 43 and 44 in which stripes in the stripe patterns 85a 
and 87a are illustrated deliberately very fine for better understanding of 
the principle. 
As best seen in FIG. 43, the distance between lines (i.e. lines 85a and 87a 
in FIG. 44) is largest on lines 91a-91b and 92a-92b connecting cross 
points of lines as marked with symbols ".largecircle.". Whereas the 
distance between lines is smaller at positions between the lines 91a-91b 
and 92a-92b. The opaque sections of the Moire stripe are produced in this 
area of smaller inter-line distance. That is, when the lines in FIG. 43 
are drawn slightly thinner than the above-described pitch P shown in FIG. 
41, the area of the smaller distance becomes opaque and the area of the 
large distance appears transparent. Such opaque and transparent sections 
form the Moire stripe pattern. 
Scanning of a lot of Moire stripes by a small key movement will now be 
explained in reference to FIG. 44 in which the above-described transparent 
sections appear on the lines 91a-91b and 92a-92ba. The following 
explanation will be focused upon such transparent sections for simpler 
understanding. 
By moving the mobile pattern plate 87 in the direction of key depression 
DR, a cross point PT1 moves to a cross point PT4 via a cross point PT1'. 
This means the fact that the line 87a1 moves to a line 87a.sub.2 and, as a 
consequence, the distance of movement of the mobile pattern plate 87 is 
equal to D. The Moire stripe pattern moves over a distance of W in FIG. 41 
in a inclined direction when the distance of key movement is equal to D. 
Thus, the multiplification factor of movement (BY) is given by the 
following equation. 
EQU BY=W/D (3) 
Watching a triangular PT1-PT2-PT3 in FIG. 44, the following relationship is 
conducted. 
EQU D=P/ sin (.theta.+.theta..sub.1) (4) 
Here, .theta..sub.1 is an angle formed between the fixed pattern line 85a 
and the direction DR of key depression. Then, the following relationship 
is conducted from the foregoing equations (1) to (4). 
##EQU1## 
When the angle .theta. is equal to 2 degrees, the angle .theta..sub.1 is 
equal to 45 degrees and the pitch P is equal to 0.1 mm, the 
multiplification factor BY is calculated from the equation (5) as follows; 
EQU BY=sin (45 degrees)/2 sin (1 degree)=20.95 (times) 
Thus, the system operates as if the key moved 20.95 times larger than its 
actual distance of movement. The interval of the Moire stripe pattern W is 
calculated from the equation (1) as follows; 
EQU W=0.1(mm)/2 sin (1 degree)=2.865(mm) 
Further, the number N of the Moire stripes pass by the photosensor is 
calculated as follows; 
EQU N=209.5(mm)/2.865(mm).apprxeq.73 
The correctness of this calculation can be endorsed by another way of 
consideration. That is, the number N is calculated as follows too; 
EQU N=10(mm)/0.1(mm).times.sin(45 degrees).apprxeq.73 
From these calculations it will be clear that the number N is equal to 100 
if the value of (.theta.+.theta..sub.1) is equal to 90 degrees. 
In the case of the foregoing embodiments, the musical tone controller is 
given in the form of a key on a keyboard electronic musical instrument as 
well as a push button on a portable electronic musical instrument. The 
present invention, however, is also applicable to an expression pedal unit 
which is generally used for tone volume control on an electronic musical 
instrument. One example of such an expression pedal unit is disclosed in 
Japanese Utility Model Application Laid Open Sho. 60-152197 which is used 
even separate from a musical instrument. The ninth embodiment of the 
electronic musical instrument in accordance with the present invention 
shown in FIG. 45 incorporates such a unique application. It should further 
be noted that this embodiment is also applicable to a built-in type 
expression unit such as disclosed in Japanese Utility Model Application 
Laid Open Sho. 62-46498. 
In FIG. 45, a foot pedal 94 is pivotally mounted to a frame 93 via a pin AX 
fastened by a nut AXa and a pair of webs 94b and 94c. This foot pedal 94 
is made of plastic material and backed up by a metallic base 94a fixed to 
its bottom face by locker 94f. At about the middle of its length the foot 
pedal 94 is provided with a drive tongue 94d projecting downwards. The 
drive tongue 94d is accompanied at its lower end with three pawls 94d1 to 
94d3 which hold a pinion 94e underneath the bottom end of the drive tongue 
94d. 
Three spacers 93b1 to 93b1 to 93b3 are arranged on the bottom face 93a of 
the frame 93 to hold a pair of overhead guide members 95 each having an 
angled groove 95a. The pair of guide members are arranged in parallel to 
each other with their angled grooves 95a in a face-to-face disposition. A 
rack 96 and a slide frame 84a are slidably received in the grooves 95a in 
the guide members 95. In this state held in the grooves 95a, the rack 96 
is kept in meshing engagement with the pinion 94e coupled to the drive 
tongue 94d of the foot pedal 94. Facing the slide frame 84a, a fixed 
pattern frame 86 is fixed to the bottom face 93a of the frame 93. The 
slide frame 84a and the fixed pattern frame 86 are provided with stripe 
patterns same as that shown in FIG. 38 which can produce a Moire stripe 
pattern. 
A light emitter 24a is arranged on the bottom face 93a of the frame 93 via 
the spacers 24c at a position just below the central section of the fixed 
pattern frame 86. Facing this light emitter 24a, is held a light collector 
24b fixed to the guide member 95 or to the bottom face 93a of the frame 
93. 
When the foot pedal 94 is pushed in the direction of an arrow A in the 
drawing with the operator's heel on the left end of the pedal in the 
illustration, the pinion 94 swings in the clockwise direction as shown 
with an arrow C and the rack 96 is driven for leftward movement with the 
slide frame 84a. Since the associated stripe patterns are designed to 
produce Moire stripe patterns as stated above, one push down of the pedal 
94 produces one pulse on the output line of the light collector 24b per 
one stripe. This pulse signal is used as a signal CK1 in the circuit shown 
in FIG. 46 and a signal CK2 in the circuit shown in FIG. 53. Use of the 
rack-pinion combination in this embodiment presents comfortable feel of 
resistance against operation by player's foot. 
In addition to the foregoing application, the present invention is 
applicable to a knee lever unit such as disclosed in Japanese Patent 
Application Laid Open Sho. 62-187890. For example, a slide member shown in 
FIG. 1 of this earlier application can be replaced by a slide frame 84a 
used for the eighth embodiment shown in FIG. 38, a mobile pattern plate 87 
in the moving ambit of the slide frame 84a and a fixed pattern plate 85 on 
a frame of the knee lever unit. By designing stripe patterns as in the 
foregoing embodiment, like Moire stripe patterns can be produced in the 
system. 
It should be understood that the present invention is similarly applicable 
to joy-stick controllers. Further, various parts used for the 
above-described embodiments are exchangeable with each other. Since pulses 
are generated in non-contact mode in correspondence with the extent of 
movement of each controller, the instrument can well endure long use with 
minimal change in function. Lots of pulse signals can be issued with 
minimal output lines for each key. 
Explanation will further be directed to the construction of the musical 
tone control parameter changing means. The first embodiment of the 
parameter changing means is shown in FIG. 46. The illustrated circuit 
includes, as the major components, a key operation pulse detection circuit 
100 electrically connected to a pulse generator PG, i.e. the pulse 
generating means such as shown in FIGS. 1 to 45, a keying detection 
circuit 110 connected to the output side of the key operation pulse 
detection circuit 100, a touch data formation circuit 130 connected to the 
output sides of the foregoing two circuits 100 and 110, a key termination 
detection circuit 120 interposed between the keying detection circuit 110 
and the touch data formation circuit 130, and a sound system 160 connected 
to the output side of the touch data forming circuit 130 via a 
multiplicating circuit 140 and a musical tone generating circuit 150. 
Here, the key operation pulse detecting circuit 100, the keying detecting 
circuit 110, the key termination detection circuit 120 and the touch data 
formation circuit 130 are each provided one for each musical tone 
controller, i.e. each key in the case of a keyboard electric musical 
instrument which is exemplified in the following descriptions. 
The key operation pulse detection circuit 110 has a function to carry out 
wave shaping of pulses issued by the pulse generator PG. In this case, 
pulses are generated in magnetic manner. This key operation pulse 
detection circuit 100 includes an amplifier 101 and a wave shaper 102. On 
receipt of a pulse signal in current form from a coil L, which corresponds 
to the coils 10, 48a, 56, 65 and 75 in the foregoing embodiments of the 
pulse generating means, the amplifier 101 amplifies and converts it into a 
pulse signal in voltage form. The wave shaper 102 performs shaping of an 
output pulse signal Ps from the amplifier 101 via differentiation and 
issues a key operation pulse Ck1 with a pulse width of a clock pulse CK0 
received from a later-described high speed oscillator 111 of the keying 
detection circuit 110. 
When the yoke associated with the coil L is constructed as shown in FIG. 
6D, the output pulse signal Ps from the amplifier 101 includes a large 
rise with a small fall during depression of the key as shown in FIG. 47A 
and a small rise with a large fall during return from key depression as 
shown in FIG. 47B. If wave shaping is carried out at the wave shaper 102 
in a manner such that only pulses exceeding the threshold level Vr shown 
in FIG. 47 should be picked up, no key operation pulses CK1 are issued 
during return from key depression. 
When pulses are generated in photoelectric manner at the pulse generator 
PG, output signals from the photosensors 24, 34, 53 and 84 may be passed 
to the wave shaper 102. Such a photosensor includes a light collector such 
as shown in FIG. 48 in which the light collector includes a light 
collecting element PD, a FET Q1 and resistances R1 and R2. 
The key operation pulse detection circuit 100 may be constructed so that it 
should issue the key operation pulse CK1 during key depression only on 
receipt of a pair of pulse signals with a phase lag of 90 degrees from the 
pulse generator PG, thereby discriminating direction of the key movement. 
In this case, the key operation pulse detection circuit 100 has a function 
to detect a phase lag in the pulse signals received from the pulse 
generator PG. 
The keying detection circuit 110 includes a normally operating high speed 
oscillator 111, the first counter 112 connected to the output side of the 
oscillator 111 to count clock pulses CK0 from the oscillator 111, a latch 
113 connected to the output side of the counter 112 to latch count values 
from the counter 112, an AND-gate G1, OR-gates G2 to G4, a D-type 
flip-flop 114 interposed between the oscillator 111 and the latch 113, the 
first preset value setter 115 which sets the first preset value P1 via a 
volume VR1 and the first comparator 116. The comparator 116 is provided 
with a terminal A for receipt of the first preset value P1 and a terminal 
B for receipt of a count value latched at the latch 113. The comparator 
116 compares the count value at the terminal B with the first preset value 
at the terminal A to issue a keying signal of level "1" when the first 
preset value is larger than the count value. 
The key termination detection circuit 120 includes the second preset value 
setter 121 for setting the second preset value P2 and a comparator 
connected to the second preset value setter 121. The comparator 122 is 
provided with a terminal A for receipt of the second preset value P2 and a 
terminal B for receipt of the count value from the latch 113 of the keying 
detection circuit 110. The comparator 122 compares the count value at the 
terminal B with the second preset value P2 at the terminal A to issue a 
key termination signal of level "1" when the second preset value P2 is 
smaller than the count value. 
The touch data formation circuit 130 includes a counter 131 for counting 
the key operation pulses CK1 from the key operation pulse detection 
circuit 100, a latch 132 for latching the count value from the counter 
131, a flip-flop 133, a differentiation circuit 134 connected to one 
output terminal Q of the flip-flop 133, a one-shot multi-vibrator 135 and 
a switch 136. The set terminal of the flip-flop 133 is connected to the 
output side of the first comparator 116 of the keying detection circuit 
110 whereas the reset terminal R to the output side of the second 
comparator 122 of the key termination detecting circuit 120. The other 
output terminal of the flip-flop 133 is connected to the reset terminal R 
of the counter 131. The multi-vibrator 135 may include a NOT-gate. 
The preset values P1 and P2 are chosen close to the maximum count value 
C.sub.MAX of the first counter 112 of the keying detection circuit 110. 
The system shown in FIG. 46 operates as follows. No key operation pulse CK1 
is issued by the key operation pulse detection circuit 100, before the key 
is depressed. 
The first counter 112 of the keying detection circuit 110 counts the clock 
pulses CK0 from the oscillator 111 and, when its count value reaches the 
maximum count value C.sub.MAX, input signals to the AND-gate G1 are all at 
level "1". As a consequence, the keying detection circuit 110 issues an 
output signal of level "1" which is passed to the latch via the OR-gate 
G3. The latch 113 issues its full count value C.sub.MAX after latching. 
When the output from the AND-gate G1 is at level "1", the output signal 
from the OR-gate G 4 is also brought to level "1". The signal is delayed 
over one period of the clock pulse CK0 by operation of the flip-flop 114 
and its reset signal from the OR-gate G2 is brought to level "1". 
Thereupon the counter 112 is reset to restart its counting of the clock 
pulses CK0 from 0. As a consequence, the output signals from the latch 113 
are thereafter maintained always at the full count value C.sub.MAX which 
is greater than the first preset value P1 fixed by the setter 115, and the 
output signal from the first comparator 116 is at level "0". Since the 
output signal from the latch 113 passed to the terminal B of the second 
comparator 122 is greater than the second preset value P2 at its terminal 
A, the output signal from the second comparator 122 is at level "1" to 
reset the flip-flop 133. Then, the output signal from the terminal reverse 
Q of the flip-flop 133 is bought to level "1" to reset the counter 131, 
thereby disenabling the same. 
When the switch 136 in the touch data formation circuit 130 is kept in the 
state shown in the drawing, an output signal of level "1" from the second 
comparator 122 is passed to the latch 132. However, the counter 131 has 
started no counting and, as a consequence, issues a count value of 0, and 
the latch 132 also issues an output signal of level "0". When the output 
signal from the comparator 122 is at level "1", the counter 112 is reset. 
At this moment the output signal at the terminal Q of the flip-flop 133 is 
at level "0" to disenable the comparator 122. As a consequence, reset on 
the flip-flop 133 and the counter 112 is canceled. This condition is 
maintained until operation on the musical tone controller, i.e. the key 
depression, is initiated. 
On the key depression, the key operation pulse detection circuit 100 
sequentially issues a number of key operation pulses CK1. As stated above, 
the number of the key operation pulses CK1 is dependent upon the extent of 
movement of the controller, i.e. the key depression in the present case. 
Whereas its pulse interval T is inversely proportional to the speed of the 
key movement. The key operation pulses CK1 so generated is on the one hand 
passed to the second counter 131 and, on the other hand, to the latch 113 
via the OR-gate G3. Further, the key operation pulses CK1 are passed to 
the reset terminal R of the first counter 112 via the OR-gate G4, the 
flip-flop 114 and the OR-gate G2. During the initial period of key 
depression, moving speed of the key is rather small and, as a consequence, 
the pulse interval T of the key operation pulses CK1 is large. The count 
values C.sub.N of the first counter 112 are latched by the latch 113 after 
they exceed the full count value C.sub.MAX of the first counter 112. Due 
to this delay in latching operation, the input signal at the terminal A of 
the first comparator 116 is maintained smaller than that at the terminal B 
at this stage of the process and its output signal is still kept at level 
"0". Thus, the second counter 131 is kept disenabled. 
With gradual increase in moving speed of the key, latching operation is 
carried out even when the count value C.sub.N of the first counter 112 
does not reach the level of the first preset value P1 and, at the first 
comparator 116, the input signal at the terminal A exceeds that at the 
terminal B. The output signal from the comparator 116 is then brought to 
level "1" and the rise of this output signal is used as a keying signal. 
This output signal of level "1" from the first comparator 116 sets the 
flip-flop 133 whose output signal at the terminal reverse Q is now at 
level "0" to cancel resetting on the counter 131. Then the second counter 
131 is rendered enabled to initiate counting of the key operation pulses 
CK1 from the key operation pulse detection circuit 100. 
On setting of the flip-flop 133, its output signal at the terminal Q is 
brought to level "1", which enables the second comparator 122 of the key 
termination detection circuit 120. At the rise of this Q terminal output 
signal, the differential circuit 134 issues a differential pulse to 
trigger the one-shot multi-vibrator 135. As a consequence, its output 
signal is temporarily brought to level "0" for a prescribed period. 
When the switch 136 is in b-connection under this condition, the rise of 
the output signal from the multi-vibrator 135 makes the latch 132 latch 
the count values from the second counter 131 to issue as touch data. These 
touch data are made up of count values generated within a prescribed 
period after the second counter 131 started counting of the key operation 
pulses CK1 on generation of the keying signal. The faster the key 
movement, that is the stronger the key touch, the larger the number of the 
touch data. 
When the switch 136 is in a-connection as shown in FIG. 46 under this 
condition, the rise of the output signal from the second comparator 122 
makes the latch 132 latch the count values from the second counter 131 to 
issue as touch data. When the key is depressed until the lower limit or 
until a certain middle position due to soft touch, the moving speed of the 
key is very low and the pulse interval T of the key operation pulses CK1 
is rendered large. Then, the count value C.sub.N of the counter 112 
becomes larger than the second preset value P2 in the key termination 
detection circuit 120, which brings the output signal from the second 
comparator 122 up to level "1". As a consequence, the touch data are made 
up of count values generated during a period from initiation of counting 
of the key operation pulses CK1 to termination of the key movement, and 
correspond to the depth of key depression. 
As the output signal from the second comparator 122 is brought up to level 
"1", the first counter 112 is reset and the second counter 131 is also 
reset with a delay equal to the reversion period of the flip-flop 133. The 
comparator 112 is also rendered disenabled as stated above. 
By setting the first present value P1 a little smaller than the full count 
value C.sub.MAX of the first counter 112, one can avoid unstable condition 
of the touch data or operation error which would otherwise be caused by 
slight key movement during the initial key depression and/or after key 
depression. 
Insensible zones can be provided in the initial and terminal periods of key 
depression by use of such prescribed values P1 and P2 and the widths of 
such insensible zones can be adjusted freely by choice of these preset 
values. 
Operation of the circuit shown in FIG. 46 during the initial period of key 
depression will now be explained in more detail. Here, the switch is 
supposed to be in the a-connection as shown in the drawing. It is also 
assumed that the length of time from the full count moment of the counter 
112 to the moment of input of the first key operation pulse CK1 is equal 
to "t", the length of time before the count value C.sub.N reaches the 
first preset value P1 is equal to "T1" and the length of time before the 
count value C.sub.N reaches the second preset value P2 is equal to "T2". 
Needless to say, T1 is shorter that T2. One of the following three 
relationships are believed to exist between these three timings. 
EQU t&lt;T1 (1) 
The latch 113 starts to latch the count value C.sub.N of the counter 112 
before the latter reaches the first preset value P1 and, as a consequence, 
the input signal at the terminal A of the comparator 116 becomes larger 
than that at the terminal B. This condition causes setting of the 
flip-flop 133 to enable the second counter 131 and the first key operation 
pulse CK1 is counted. Since t is smaller than T2, the output signal from 
the second comparator 122 is kept at level "0" and no resetting of the 
flip-flop 133 is caused. The latch 132 performs no latching and its output 
signal remains also at level "0". 
EQU T1&lt;t&lt;T2 (2) 
The latch 113 starts its action after the count value C.sub.N has exceeded 
the first preset value P1 and, as a consequence, the input signal at the 
terminal A of the comparator 116 becomes smaller that at the terminal B. 
As a result, the counter 131 remains disenabled. Since the output signal 
from the comparator 122 is also at level "0", the latch 132 does not 
operate. 
EQU t&gt;T2 (3) 
The output signal from the comparator 116 is at level "0" and the counter 
131 remains disenabled. The input signal at the terminal A of the 
comparator 116 becomes smaller than that at the terminal B but the 
comparator 116 remains disenabled because of level "0" state of the output 
signal from the terminal Q of the flip-flop 133. The level "0" output 
signal from the flip-flop 133 causes no operation of the latch 132. 
There is an error of 1 in the count value C.sub.N of the counter 112 
between the case (1) and the cases (2) and (3). Presence of such an error 
in count value, however, has no virtual influence on the operation of the 
illustrated circuit, since one time of key depression generates 50 to 100 
pulses. 
The above-described major circuits are each provided one for one key, i.e. 
musical tone controller, and the touch data issued by the latch 132 is 
passed to the multiplicating circuit 140 which transfers the same to the 
musical tone generating circuit 150 in time division mode. The circuit 150 
generates a musical tone signal at a tonal pitch corresponding to the key 
of the touch data received from the latch 132. Depending on the values of 
the touch data received, a wide variety of musical tone control parameters 
can be changed in multi-stage fashion, thereby generating musical tone 
signals with complete fidelity to delicate change in player's emotion as 
well as strength and speed of key depression, i.e. operation on the 
musical tone controller. Such musical tone signals are passed to the sound 
system 160, which generally includes an amplifier 161 and a speaker 162, 
for generation of corresponding musical tones via electro-acoustic 
conversion. 
In accordance with the foregoing embodiment of the parameter changing means 
of the present invention, a keying signal is generated at the moment of 
prescribed key depression speed to initiate counting of the key operation 
pulses CK1 by the second counter 131. The above-described prescribed key 
depression speed can be changed quite freely by adjustment of the first 
and second prescribed values P1 and P2. This enables free setting of the 
threshold level of the insensible zone during the initial period of key 
depression. 
More specifically, the relationship between the touch strength and the tone 
volume level is shown in FIG. 50. Here the tone volume level of a musical 
tone is fixed on the basis of touch data obtained in the a-connection 
state at the switch 136. It is clear from this graphic data that the lower 
the touch strength, the lower the tone volume level for a small preset 
value P1. Whereas no significant lowering in tone volume level is observed 
in the case of high touch strength. Thus an enlarged dynamic range can be 
expected. 
This is due to the following state of signal processing. The key depression 
speed is low for a low touch strength. When the first preset value P1 is 
small, initiation of counting of the key operation pulses CK1 by the 
counter 131 is delayed accordingly after the initial key depression and 
increased number of pulses are issued without counting. As a result, the 
size of the touch data from the latch 132 is minimized to lower the 
resultant tone volume level. In the case of high touch strength, however, 
even for the small first preset value P1, instant generation of the keying 
signal and early initiation of counting operation by the counter 131 
occur. Then, reduction in number of pulses issued without counting causes 
no significant change in size of the touch data regardless of the size of 
the first preset value and, as a result, no lowering in tone volume level 
takes place. 
Such possibility in change of the dynamic range leads to enlarged freedom 
in trill performance whilst well reflecting delicate change in player's 
emotion. This merit of the invention can be utilized in tone volume 
control on an automatic piano too. For example, for memory of the initial 
touch data with tonal pitch information and note length information, the 
first preset value P1 is chosen very close to the full count value of the 
counter 112 or very large. The value is set to a relatively low level for 
replaying. With this setting of the value, movement of a key caused by a 
soft touch produces no musical tone, thereby enabling severe reflection of 
the player's technique. 
Although the major circuits are each provided one for each key in the case 
of the foregoing embodiment, only one set of combination may span a 
plurality of keys when time division mode is employed in signal 
processing. The operations of these major circuits may be program 
controlled via use of a micro-computer too. 
The second embodiment of the musical tone control parameter changing means 
is shown in FIGS. 51 and 52, in which FIG. 51 contains only a circuit 
section corresponding to the touch data formation circuit 130 in the 
foregoing embodiment and other circuit sections are substantially same as 
those used for the foregoing embodiment. 
As in the first embodiment, a touch data formation circuit 230 includes the 
second counter 131, the flip-flop 133 and the differential circuit 134. In 
addition thereto, the circuit 230 includes four sets of latches 132a to 
132d connected in parallel and four sets of one-shot multi-vibrators 135a 
to 135d connected in series. A rise from level "0" to level "1" in an 
output signal from each multi-vibrator is used as a latch signal for an 
associated latch. Three reducers 137a to 137c are interposed between the 
output terminals of the latches 132a and 132b, between the output 
terminals of the latches 132b and 132c and between the output terminals of 
the latches 132c and 132d, respectively. Each reducer is designed to issue 
an output signal (B-A) which is a difference between its A terminal input 
and B terminal input. Together with the output signal from the latch 132a, 
output signals from the reducers 137a to 137c are put out to a 
multiplicating circuit 140 as touch data via AND-gates 139a to 139c. 
A comparator 138a is provided with an A terminal to receive an output 
signal (A) from the latch 132a and a B terminal to receive an output 
signal (B) from the reducer 137a. On receipt of these signals, the 
comparator 138a issues an output signal of level "1" when C&lt;(A-B), C being 
a properly chosen positive integer such as 3. This output signal is 
reversed at a NOT-gate N1 to be passed to the AND-gate 139a as a prohibit 
signal so that the AND-gate 139a should be closed when the inhibit signal 
is at level "0". Likewise, a comparator 138b is arranged on the output 
sides of the reducers 137a and 137b so that its output signal should be 
passed to the AND-gate 139b as an inhibit signal after inversion at a 
NOT-gate N2, and a comparator 138c is arranged on the output sides of the 
reducers 137b and 137c so that its output signal should be passed to the 
AND-gate 139c as an inhibit signal after inversion at a NOT-gate N3. 
With this construction of the touch data formation circuit 230, the 
flip-flop 133 is set on receipt of a keying signal which is generated when 
the output signal from the comparator 116 in FIG. 46 is at level "1". Its 
resultant output signal of level "0" at the reverse Q terminal enables the 
counter 131 which thereupon initiates counting of the key operation pulses 
CK1. Concurrently, the differential circuit 134 issues a differential 
pulse at rise of the Q terminal output signal from the flip-flop 133 to 
trigger the multi-vibrator 135a. With prescribed time lags, the 
multi-vibrators 135b to 135d are triggered one by one to pass latch 
signals to the latches 132a to 132d sequentially. So, when the delay time 
by the multi-vibrator is .tau., the latches 132a to 132d operate at 
timings .tau., 2.tau., 3.tau. and 4.tau. after counting of the key 
operation pulses CK1 is initiated at the counter 131. 
The output signal from the latch 132a is used as touch data (1). Whereas 
output signals from the reducers 137a to 137c are used as touch data (2), 
(3) and (4) after passage through the AND-gates 139a to 139c. When the 
output signal from the latch 132a exceeds the value C or when the 
difference between the output signals of upstream and downstream reducers 
exceeds the value C, the output signal of each reducer becomes level "1" 
to make the output signal from an associated NOT-gate be at level "0" and 
an associated AND-gate is closed to issue no touch data. 
Assuming that the output signals from the latches 132a to 132d are equal to 
22, 53, 64 and 64, the touch data (1) are equal to 22. The output signals 
from the reducers 137a to 137c are equal to 31, 11 and 0, respectively. 
The value (A-B) at the comparator 138a is then equal to -9. When the value 
C is equal to 3, the value (A-B) is not smaller than the value C and, as a 
consequence, the output signal from the comparator 138a becomes level "0". 
Because the output signal from the NOT-gate N1 is at level "1", the 
AND-gate 139a is made open and the output signal 23 from the reducer 137a 
forms the touch data (2). The value (A-B) at the comparator 138b is then 
equal to 20 which is larger than the value C and the output signal from 
the comparator 138b becomes level "1". As a consequence, the output signal 
from the NOT-gate N2 is at level "0" and the AND-gate 139b is closed. The 
output signal 11 from the reducer 137b doesn't form the touch data (3). 
The output signal from the reducer 137c is at level "0" and the AND-gate 
139c is also closed to issue no touch data (4). 
When a key is depressed slowly, input of the key operation puleses CK1 
lasts until the latch 132d latches the count value from the counter 131 
and four latch data are exactly obtained as the case 1 in FIG. 52A. 
Whereas, when the key is depressed strongly, input of the key operation 
pulses CK1 terminates before the latch 132c starts to latch the count 
value from the counter 131 as the case 2 in FIG. 52B and output of signals 
from the reducer 137b is inhibited because no correct number of pulses are 
generated during the period .tau.. In this case a value obtained by adding 
the difference between the data (2) and (1) to the data (1) via 
interpolation may be used for the data (3). In the above-described real 
example, a value 40=31+9 may be used for the data (3). 
This embodiment of the parameter changing means can be used for tone volume 
control such as control of the attack level of an envelope wave shape 
utilizing the touch data (1). The touch data (1) to (n) or difference 
between each touch data (1) to (n) can be used for tone colour control, 
control of the sustain period of an envelope wave shape and control of 
pitch variation as well as the depth and speed of vibrato and tremolo. The 
touch data can also be used for control of tone colour in the next 
spectrum division (harmonic combination, etc). In this way, this 
embodiment assures subtle control of musical tones and rich reflection of 
the player's emotion. By increasing the number of the latches and the 
multi-vibrators, one key depression period can be divided into more time 
sections to obtain more touch data. 
When the circuit is constructed so that the counter 131 should be reset at 
every latching operation by the latch to restart its counting operation, 
the reducers 137a to 137c can be deleted from the circuit construction. 
The operation of the touch data formation circuit 230 may be given by 
software programming on a micro computer too. 
The third embodiment of the parameter changing means is shown in FIG. 53 in 
which the key operation pulses CK1 are issued from a key operation pulse 
detection circuit 100' after shaping not only during key depression but 
also during return from key depression. This circuit is different from the 
foregoing embodiment in the construction of a touch data formation circuit 
330 and a key return signal detection circuit 170. 
The touch data formation circuit 330 includes the second counter 131, the 
flip-flop 133 connected to the first comparator 116, a latch 332 provided 
with a clear terminal CLR, a selector 333 connected to the output side of 
the latch 332, a preset value setter 334, a coincidence detection circuit 
335 having an A terminal connected to the counter 131 and a B terminal 
connected to the setter 334, a flip-flop 336 having an S terminal 
connected to the coincidence detection circuit 335 and an R terminal 
connected to the key return signal detection circuit 170, two D-type 
flip-flops 337 and 338 connected in series and an AND-gate 339 leading to 
the L terminal of the latch 332. 
The key return signal detection circuit 170 has a function to issue a 
return pulse before complete return of a key on the basis of a signal 
issued by a proximity sensor NS which is given in the form of the coil 54a 
in FIGS. 25 and 28 or the coil 57 in FIG. 29 and like. This circuit 170 
includes a D-type flip-flop 171 connected to the proximity sensor, a 
NOT-gate 172 and an AND-gate 173 provided on the output side of the 
flip-flop 171. 
As the proximity sensor NS issues a pulse signal "a" such as shown in FIG. 
54 during key depression, the flip-flop 171 issues a pulse signal "b" in 
FIG. 54 with a time lag corresponding to one clock pulse CKO. The NOT-gate 
172 issues a pulse signal "c" in FIG. 54 after inversion of the pulse 
signal "a" and the AND-gate issues a key return pulse signal "d" such as 
shown in FIG. 54 on receipt of the pulse signals "b" and "c". The system 
is designed so that this key return pulse signal "d" should be issued at a 
position II of the key K in FIG. 55 between the uppermost position I and 
the lowermost position III. As illustrated, this position II is located 
just before the uppermost position I. This key return pulse signal "d" is 
passed to the flip-flop 336 as a reset signal and to the latch 332 as well 
as the flip-flop 337 and 338 as clear signals. 
Before key depression, the flip-flop 336 is kept reset and the latch 332 as 
well as the flip-flops 337 and 338 are kept cleared due to receipt of the 
key return pulse signal "d" issued in the foregoing cycle. A small value 
such as a value between 2 and 4 is chosen for the preset value at the 
setter 334. 
As key depression is initiated, key operation pulses CK1 are issued by the 
key operation pulse detection circuit 100' at a pulse interval inversely 
proportional to the key depression speed. When the key depression speed 
exceeds a prescribed value, the output signal from the comparator 116 of 
the key detection circuit 110 becomes level "1" to set the flip-flop 133 
and cancel the reset condition of the counter 131. The counter 131 
continues to count subsequent key operation pulses CK1 and, when its count 
value reaches the preset value P3, A and B terminal input signals becomes 
equal at the coincidence detection circuit 335 which thereupon issues an 
output signal at level "1" to set the flip-flop 336. Input signals to the 
flip-flops 337 and 338 then become level "1". 
When key operation pulses CK1 are generated due to accidental key vibration 
or unexpected finger touch on a key, a resultant small count value is not 
latched in accordance with this embodiment of the parameter changing 
means. This can be also said to a case when the key operation pulses CK1 
are counted partly before the key depression speed reaches the preset 
value. Thus, this circuit well avoids the trouble of incorrect issue of 
the initial touch data which is otherwise caused by unintended generation 
of the key operation pulses CK1. 
Counting of the key operation pulses CK1 is continued by the counter 131. 
As the key arrives at its lowermost position III, stop of the key movement 
makes the comparator 122 issue an output signal at level "1", the AND-gate 
339 issue a latch signal at level "1" and the latch 332 latch the instant 
count value from the counter 131. Input of the pulses to the CK terminals 
of the flip-flop 337 and 338 makes the flip-flop 337 issue an output 
signal at level "1" and the selector 333 be enabled. 
Under this condition, the selector 333 accepts the count value latched by 
the latch 332 to issue as the initial touch data to be passed to the 
multiplicating circuit 140 shown in FIG. 46. Concurrently, the flip-flop 
133 is reset to issue an output signal at level "1" at its reversed Q 
terminal to disenable the counter 131. 
As the key starts to ascend from its lowermost positon III, the key 
operation pulses CK1 are again generated to be detected by the key 
detection circuit 110. Then the counter 131 is released from its reset 
condition to restart counting of the key operation pulses CK1. 
When the key stops before reaching the midway position II, the pulse signal 
from the key termination detection circuit 120 makes the latch 332 latch 
the instant count value from the counter 131. An output signal at level 
"1" appears at the D terminal of the flip-flop 338. On receipt of a pulse 
signal at its CK terminal, the flip-flop 338 issues an output signal at 
level "1" at its terminal Q to give a switch signal to the selector 333. 
Thereupon, the selector 333 accepts the count value latched at the latch 
332 to issue after touch data to the multiplicating circuit in FIG. 46. 
Every time the key thereafter moves in an area between the positions II and 
III, the counter 131 counts the key operation pulses CK1 and its count 
values are latched by the latch 332 to make the selector 333 issue after 
touch data. 
On return to the key to above the midway position II, the key return signal 
detection circuit 170 issues the key return pulse "d" to clear the latch 
332 as well as the flip-flop 337 and 338 and the selector 333 is made 
disabled. As a consequence, the count values from the counter 131 are not 
issued as the after touch data. When the key returns directly to its 
uppermost position I right after full depression, only the initial touch 
data are is issued with no issue of the after touch data. 
Such a circuit is provided one for each musical tone controller, i.e. each 
key and the initial touch and after touch data issued from each touch data 
formation circuit 330 are passed to the multiplicating circuit 140 which 
transfers the same to the musical tone generating circuit 150 in a time 
division mode. The initial touch data controls various musical tone 
control parameters such as tone volume in multi-stage fashion whereas the 
after touch data also controls various musical tone control parameters 
such as delay vibrato, tremolo, change in pitch, change in tone colour and 
sustain wave shape. These two touch data can be detected by a single 
common circuit.