U.S. patent number 3,626,350 [Application Number 05/011,983] was granted by the patent office on 1971-12-07 for variable resistor device for electronic musical instruments capable of playing monophonic, chord and portamento performances with resilient contact strips.
This patent grant is currently assigned to Nippon Gakki Seizo Kabushiki Kaisha. Invention is credited to Takatosi Okumura, Shoichi Suzuki.
United States Patent |
3,626,350 |
Suzuki , et al. |
December 7, 1971 |
VARIABLE RESISTOR DEVICE FOR ELECTRONIC MUSICAL INSTRUMENTS CAPABLE
OF PLAYING MONOPHONIC, CHORD AND PORTAMENTO PERFORMANCES WITH
RESILIENT CONTACT STRIPS
Abstract
A variable resistor utilized as a keyboard of an electronic
musical instrument is comprised of an elongated rectangular base
member, a plurality of strip-shaped resistor bodies formed on one
surface of the base member, a resilient pressure contact member
covering resistor bodies and a plurality of mutually spaced apart
strips of metal mounted on the inner surface of the pressure
contact member to confront the resistor bodies with a small gap
therebetween. By continuously varying the point of contact between
the resistor body and the metal strip it is possible to produce
monophonic chord and portamento signals and to vary the coloring
and volume of the musical tone signals, or each or combinations of
them.
Inventors: |
Suzuki; Shoichi (Hamamatsu,
JA), Okumura; Takatosi (Hamamatsu, JA) |
Assignee: |
Nippon Gakki Seizo Kabushiki
Kaisha (Nakazawa-cho, Hamamatsu-shi, Shizuoka-ken,
JA)
|
Family
ID: |
27455805 |
Appl.
No.: |
05/011,983 |
Filed: |
February 17, 1970 |
Foreign Application Priority Data
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|
Feb 20, 1969 [JA] |
|
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45/12442 |
Feb 20, 1969 [JA] |
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45/14387 |
Feb 20, 1969 [JA] |
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45/12438 |
Feb 20, 1969 [JA] |
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45/14388 |
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Current U.S.
Class: |
338/69; 84/DIG.7;
338/96; 338/99; 84/DIG.8; 338/199; 984/321 |
Current CPC
Class: |
G10H
1/0558 (20130101); H01C 10/00 (20130101); H03H
7/24 (20130101); Y10S 84/07 (20130101); Y10S
84/08 (20130101) |
Current International
Class: |
H01C
10/00 (20060101); H03H 7/24 (20060101); G10H
1/055 (20060101); H01c 009/02 () |
Field of
Search: |
;338/47,92,96,199,69 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myers; Lewis H.
Assistant Examiner: Tolin; Gerald P.
Claims
What we claim is:
1. A variable resistor for controlling the operation of an
electronic musical instrument in response to manual operation
comprising an electrical insulating base member, a plurality of
mutually insulated elongated, strip-shaped first electrical
conductors carried by one surface of the base member, said first
conductors having mutually parallel axes, a resilient pressure
contact member spaced from and covering the first electrical
conductors, a plurality of mutually insulated, elongated
strip-shaped second electrical conductors fixedly secured to and
carried by a surface of the resilient contact member facing the
first electrical conductors, said second conductors having mutually
parallel axes, the axis of each first conductor being aligned with
the axis of a different one of each second conductor, said first
and second plurality of conductors normally being spaced from each
other whereby conductors of the first and second conductors are
arranged in cooperating pairs adapted to engage each other in
response to manual depression of a selected portion of the contact
member, each of the conductors of one of said first or second
plurality of conductors being a resistive body the resistance of
which increases from one end of the strip to the other end of the
strip, each of the conductors of the other one of the plurality of
conductors being a metal conductive strip having a resistance much
less than the resistance of the resistive body, and means for
preventing more than one cooperating pair of first and second
conductors from contacting each other in response to a single
manual depression of a portion of the resilient pressure contact
member aligned with the cooperating pair, said contact member and
each of the plurality of second conductors having sufficient
resiliency to establish point contact between aligned regions of
each cooperation pair substantially aligned with a manual
depression point of the resilient pressure contact member.
2. The resistor of claim 1 wherein the means for preventing
comprises ridges between adjacent ones of the first conductors,
said ridges extending toward the resilient pressure contact
member.
3. The variable resistor of claim 2 wherein the pressure contact
member is formed as a channel having sidewalls fitted to
corresponding sidewalls of the base member.
4. The resistor of claim 1 wherein the means for preventing
comprises ridges between adjacent ones of the first conductors,
said ridges extending toward and into contact with the resilient
pressure contact member.
5. The resistor of claim 1 wherein the means for preventing
comprises ridges between adjacent ones of the first conductors,
said ridges extending toward and terminating in spaced relationship
with the resilient pressure contact member.
6. The resistor of claim 1 wherein the resistance of the resistive
body varies continuously from one end of the strip to the other end
of the strip.
7. The variable resistor of claim 1 wherein the pressure contact
member is formed as a channel having sidewalls fitted to
corresponding sidewalls of the base member.
Description
BACKGROUND OF THE INVENTION
This invention relates to a variable resistor for operating an
electronic musical instrument which enables a player to operate the
musical instrument in substantially the same manner as an ordinary
electronic musical instrument provided with a keyboard and more
particularly to a variable resistor which permits the player to
produce a monophonic signal as well as a chord signal of any tone
pitch, or a portamento signal wherein the tone pitches of the
monophonic and chord signals are continuously varied and to readily
vary the pitch and tone color of the musical tone signals or to
perform such operations singly or in combination.
As a recent trend it is highly desirable for electronic musical
instruments to be provided with an operating portion which can
produce a variety of musics with as far as possible simple
operation.
However in the conventional keyboard-operated musical instrument
although it is possible to produce a monophonic, chord or glissando
signal of any tone pitch it is not possible to produce a portamento
signal wherein the tone pitch is varied continuously. According to
one operating portion of a prior art musical instrument capable of
playing the portamento, for example, in the Ondes Martenot, a
ribbon with rings for receiving fingers is passed in an endless
form around a plurality of spaced-apart pulleys and the ribbon is
moved toward right or left to continuously vary the capacitance
values of variable capacitors so as to continuously vary the
oscillation frequencies of a variable-frequency oscillator, thus
continuously varying the tone pitch.
However, with the operating portion of the above-described
construction playing of only portamento wherein the tone pitch is
varied continuously is possible and it is not possible to play
melodies wherein sounds of any tone pitch are varied
discontinuously or stepwisely. Thus, said arrangement is
constructed to play monophonic signals alone and is not suitable to
play chord signals.
Another example of the operating portions for prior art musical
instrument capable of playing portamento involves utilization of a
normal close-type sliding resistor as an element for determining
the oscillation frequency of a variable-frequency oscillator acting
as a tone signal generator.
However, with such an operating portion utilizing a normal close
type variable resistor, similar to above-described Ondes Martenot,
although it is possible to play a portamento signal, it is
difficult to play a melody signal. Moreover, it is difficult to
start to play from any desired point unless the contact of the
resistor has previously been set to a desired position. Thus, it is
not possible to provide rapid and smooth play. Moreover, there is a
problem that during play slide noises are introduced owing to the
sliding contact of the variable resistor.
SUMMARY OF THE INVENTION
Accordingly, it is the principal object of this invention to
provide a novel variable resistor for operating an electronic
musical instrument having a simple normal open contact type
construction and can be operated in substantially the same manner
as a keyboard of a conventional keyboard-operated electronic
musical instrument, said variable resistor being used as an element
for determining the oscillation frequency of a variable-frequency
oscillator acting as a tone signal generator, a variable tone
coloring controller of a tone-coloring filter, or a variable volume
controller for variably controlling the volume of the musical tone
signal whereby to enable to play not only monophonic, chord and
portamento signals but also to readily and smoothly vary the volume
and/or coloring of the musical tone signals.
In accordance with this invention, there is provided a variable
resistor for operating an electronic musical instrument comprising
an elongated rectangular base member, a plurality of strip-shaped
resistor bodies formed on one surface of the base member, a
resilient pressure contact member covering the surface of the base
member on which the resistor bodies are carried and a plurality of
mutually spaced apart strips of conductive metal respectively
confronting the resistor bodies with a small gap therebetween.
Alternatively, each pair of a resistor body and a strip of metal
may be enclosed by independent base member and pressure contact
member. Thus, the resistor is of a normally open type wherein, only
when a selected portion of the pressure contact member is depressed
a selected portion of the metal strip is caused to contact the
corresponding portion of the resistor body, thereby freely
controlling each or combinations of the frequency of signals from
said variable-frequency oscillator acting as a tone signal
generator, the color of tone signals from a tone-coloring filter
and the volume of the musical tone signals. As a result, an
electrical musical instrument with a fingerboard comprised of the
novel variable resistor can be operated with a single or plurality
of fingers of one or both hands capable of starting from any
desired point just in the same manner as the conventional keyboard
electronic musical instrument. Moreover, portamento can be readily
played by mere continuous movement of the finger along the
fingerboard comprised of the novel resistor, it is not only
possible to play monophonic music, chord, portamento signals but
also to continuously and smoothly vary the coloring and volume of
the musical tone signals.
The fingerboard comprised of the novel resistor may be combined
with a conventional keyboard to increase the variety of the
music.
BRIEF EXPLANATION OF THE DRAWINGS
FIGS. 1 to 3 shown perspective views of different embodiments of
the novel variable resistor;
FIG. 4 is a block diagram of operating units of an electronic
musical instrument utilizing novel variable resistors as the
frequency-determining elements of variable-frequency
oscillators;
FIG. 5 shows a detailed circuit construction of one of the
operating units shown in FIG. 4;
FIG. 6 shows a modified circuit construction of the operating
unit;
FIGS. 7 and 8 are diagrams to explain methods of playing an
electronic musical instrument with operating units shown in FIG.
4;
FIG. 9 shows a diagram to show the application of the novel
variable resistor as a tone-coloring filter;
FIG. 10 is a similar diagram to show the application of the novel
variable resistor as a volume controller;
FIGS. 11 and 12 are plan views of two-stage and three-stage
manuals, respectively incorporating the operating units shown in
FIG. 4 as one of the stages; and
FIG. 13 is a plan view of a modified keyboard arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the accompanying drawings which shows a
perspective view of one embodiment of this invention, there is
shown a variable resistor 19A comprising an elongated rectangular
base member 13A of an insulator such as wood, plastics or the like.
On one wider surface 11 of the base member are provided a plurality
of (for example four) equally spaced longitudinal grooves 121, 122,
123 and 124 having a depth of approximately 2 to 3 mm. to
respectively receive elongated strip-shaped resistor bodies 141,
142, 143 and 144, each about 1 to 2 mm. thick. It is desirable that
barriers 151, 152 and 153 provided between adjacent grooves 121 and
124 have a height lower than that of opposite sidewalls 161 and 162
by about 0.01 to 1 mm. in order to facilitate the depression
operation to be described later. The upper surface of the base
member 13A is covered by a channel-shaped cover or a pressure
contact member 18A made of an insulator having sufficient
resiliency and flexibility such as nylon and the like plastics. On
the inner surface of the cover 18A there are provided 4 elongated
strip-shaped conductive metal films 171, 172, 173 and 174 having
substantially the same configuration as the resistor bodies 141 to
144. These metal films are vapor deposited or suitably bonded to
the inner surface to oppose respective resistor bodies with a small
spacing of about 1 to 2 mm. therebetween. Side flanges of the cover
snugly fit against longitudinal side surfaces of the base
member.
With this construction, respective metal films 171 to 174 are
normally spaced apart a small distance from respective resistor
bodies 141 to 144 on the base member 13A. When a point or points on
the cover 18A corresponding to one or more resistor bodies 141 to
144 are depressed by a finger or fingers of right or left hand
corresponding portion or portions of the metal film are caused to
come into contact opposing resistor bodies whereby the resistor can
be used as a normal open contact type variable resistor whose
resistance value is varied only when the cover is depressed. By
continuously moving the contact point to the right or left along
the longitudinal length of the resistor bodies the resistance value
of the resistor can be varied continuously and smoothly. Where
suitably spaced apart taps (not shown) are provided along the
length of respective resistor bodies the resistance value is varied
discontinuously or stepwisely.
FIG. 2 is a perspective view of a modified embodiment of the novel
variable resistor 19B. While in the previous embodiment resistor
bodies 141 to 144 are disposed in independent grooves 121 to 124 of
base member 13A, in this modified embodiment, all resistor bodies
141 to 144 are disposed in a common wide groove or recess 12 formed
in one surface 11 of base member 13B. It will be clear that this
modified variable resistor 19B can act substantially in the same
manner as the variable resistor 19A of the previous embodiment.
However, with this modification wherein all resistor bodies 141 to
144 are disposed in a common wide groove, upon depression of a
selected portion of the cover 18B facing to a selected one of the
resistor bodies, not only the selected portion of a selected
resistor body but also other resistor bodies adjacent thereto are
simultaneously contacted opposing conductive metal films 171 to
174. This problem can be alleviated by increasing the spacing
between adjacent metal films.
FIG. 3 shows another modification of the novel variable resistor
19C comprising a base member 13C, a single resistor body 121 and a
conductive metal film 171 attached on the inner surface of a cover
18C. Any desired number of such variable-resistor unit may be
combined (parallelly arranged) to form a variable resistor
comparable with those shown in FIGS. 1 and 2. In this modification,
the base member and cover may not necessarily be made of insulator
but may be fabricated with a suitable resistance material and
metal.
FIG. 4 is a block diagram of an operating portion of an electronic
musical instrument utilizing variable resistors shown and described
with reference to FIGS. 1, 2 or 3 as the frequency-determining
elements of variable-frequency oscillators serving as tone signal
generators. Thus, four pressure contact units 21a, 21b, 21c and 21d
of the variable resistor 19A each including an elongated resistor
body and a metal film which is normally spaced apart therefrom a
small distance are arranged in a juxtaposed relationship similar to
a keyboard of a conventional electronic musical instrument and
connected to function as the frequency or tone pitch determining
elements of variable-frequency oscillators or tone signal
generators 22a, 22b, 22c and 22d thus forming the first to fourth
performing units 23a, 23b, 23c and 23d of the electronic musical
instrument.
FIG. 5 shows a detailed circuit construction of one (for example
23a) of performing units 23a to 23d shown in FIG. 4. The opposite
ends of an elongated resistor body 141 of a pressure contact unit
21a are connected across positive and negative terminals 31p and
31n of a DC source 31. One end of an elongated metal film 171 is
connected to input terminals of a pair of active circuit elements,
for example, gate terminals G.sub.1 and G.sub.2 of a pair of field
effect transistors FET.sub.11 and FET.sub.12 which are connected as
shown to constitute portions of a pair of CR time constant circuits
321 and 322 acting as the frequency-determining elements of a tone
signal generator shown as an astable multivibrator including a pair
of NPN-type transistors TR.sub.11 and TR.sub.12.
When utilized in the performing units of the electronic musical
instrument thus far described, the novel variable resistor acts as
a kind of variable DC voltage generator. Thus, whenever any
selected portion of the metal film 171 is depressed into contact
the corresponding portion of the resistor body 141 a desired DC
voltage can be produced by varying the conductivity or equivalent
internal resistance of field effect transistors FET.sub.11 and
FET.sub.12 thus producing tone signals of any desired tone
pitch.
FIG. 6 shows a modified circuit construction of a performing unit
231a utilizing the novel variable resistor. In this embodiment, the
pressure contact unit 21a is connected, in the following manner, to
a CR oscillation frequency-determining network of a wien bridge
type variable-frequency oscillator 41, said network comprising a
plurality of series circuits connected in parallel across positive
and negative terminals 42p and 42n of a DC source, said series
circuits including a plurality of series combinations of capacitors
and resistors 431, 432 ... 43n and parallel combinations of
capacitors and resistors 441, 442 ... 44n. More particularly,
suitably spaced apart points along the length of the elongated
resistor body 141 are connected to respective junctures of the
series combinations 431 and 43n and parallel combinations 441 to
44n of capacitors and resistors. Similar to the embodiment shown in
FIG. 5 by depressing a selected portion of the metal film 171 into
contact the corresponding portion of resistor body 141 a tone
signal of any desired pitch can be produced.
An electronic musical instrument utilizing a plurality of
juxtaposed performing units as shown in FIG. 5 or FIG. 6 can
produce not only monophonic music, chords and portamentos but also
a variety of musics. For example, the first to fourth performing
units 23a to 23d are preset to produce tone signals of the pitch
(frequency) ratio of 4:5:6:7. Then, as shown in FIG. 7,
simultaneous playing of three performing units 23a, 23b and 23c by
depressed means of a single finger 51 results in the production of
tone signals of C, E and G for a major chord of C whereas
simultaneous operation of all performing units 23a to 23d results
in the production of tone signals of G, B, D and F for a 7th chord
of G.sub.7. Under these conditions, when the finger is moved
upwardly or downwardly dispersed chord (Alberti bass) signals of C,
E, G and B.sup.b may be obtained. Furthermore, as shown in FIG. 8,
by the simultaneous operation of the first to the third performing
units 23a, 23b and 23c with three fingers 51a, 51b and 51c (only
51b is offset by a semitone leftward) tone signal of C, Eb, and G
for a minor chord of Cm may be produced.
While in the foregoing embodiments all performing units 23a to 23d
are associated with tone signal generators, when one or a plurality
of units are used as a portion of a tone-coloring filter 61, as
shown in FIG. 9 or as a portion of a volume controller 62 as shown
in FIG. 10, in addition to the monophony, chord and portamento
described above, it is possible to vary the color and/or volume of
the musical tone signals.
Further, it will be clear to those skilled in the art that the
depth and speed of vibrato modulation and tremolo modulation or
buildup and attenuation characteristics of attack effect,
percussion effect, sustain effect can be readily controlled.
While each one of the above-described performing units 23a to 23d
can be effectively used as the performing portion of an electronic
musical instrument, by incorporating them into a conventional
keyboard operated electrical musical instrument in the following
manner it is possible to obtain a novel electronic musical
instrument capable of producing a variety of musics.
FIG. 11 shows a plan view of two stage manuals. The upper keyboard
71 has a construction similar to that of a conventional musical
instrument and includes a plurality of keys 711, 712 ... 71n
whereas the lower fingerboard comprises four performing units 23a
to 23d which are disposed in parallel with the upper keyboard 71 so
that they can be operated in the same manner as the upper keyboard.
Each of the performing units comprises spaced-apart resistor body
and a metal film as described above.
FIG. 12 shows a plan view of three-stage manuals wherein a
fingerboard of performing units 23a to 23d is interposed between
upper and lower keyboards 81 and 82 in the same manner as in FIG.
11.
Where it is difficult to dispose performing units 23a to 23d in
parallel with another keyboard as shown in FIGS. 11 and 13, such
performing units may be disposed at right angles to the keyboard 91
including a plurality of keys 911, 912 ... 91n, and on one end of
the keyboard, as shown in FIG. 13.
With a musical instrument having a manual arrangement shown in
FIGS. 11, 12 or 13 the conventional keyboard may be operated by one
hand to produce a melody signal and/or accompanying signal while
the performing units 23a to 23d by the other hand to produce a
variety of musics as above described.
* * * * *