US3624583A

US3624583A - Playing devices for electronic musical instruments

Info

Publication number: US3624583A
Application number: US12096A
Authority: US
Inventors: Akira Nakada
Original assignee: Nippon Gakki Co Ltd
Current assignee: Nippon Gakki Co Ltd
Priority date: 1969-02-20
Filing date: 1970-02-17
Publication date: 1971-11-30
Anticipated expiration: 1988-11-30
Also published as: JPS4842962B1

Abstract

A fingerboard-type playing device for an electronic musical instrument comprises an elongated resistor, a plurality of conductor taps spaced apart from each other and contiguously aligned in a row parallel to and by the resistor, and a flexible contact disposed over the elongated resistor and the conductor taps with a small space normally apart therefrom. A depression of the flexible contact makes an electric connection between the flexible contact and the elongated resistor or between the flexible contact and the conductor tap to sound a tone having the pitch determined by the depression point.

Description

United States Patent RH 1 i 1 Inventor Akira Nakada Hamamatsu, Japan Appl. No. 12,096 Filed Feb. 17, 1970 Patented Nov. 30, 197i Assignee Nippon Gakkl Sel zo Kabushikl Kalsha Hamamatsu-s hi, Shizuoka-lten, Japan Priority Feb. 20, 19691 Japan i PLAYING DEVICES FOR ELECTRONIC MUSICAL INSTRUMENTS 6 Claims, 8 Drawing Figs.

us. on; ass/69, 338/95, 338/154, 84/124, 84/D1G. 7 lnt.Cl. 1101c 9/06 Field oi Search 338/47, 68,

69, 92, 95, 96,154, 334; 84/124, DIG. 7

[56] References Cited UNITED STATES PATENTS v 1,847,119 3/1932 Lerteset al. 338/69X 2,141,231 12/1938 Trautwein Primary Examiner Lewis H. Myers Assistant Examiner-D. A. Tone Attorney-George B. Oujevolk ABSTRACT: A fingerboard-type playing device for an electronic musical instrument comprises an elongated resistor, a plurality of conductor taps spaced apart from each other and contiguously aligned in a row parallel to and by the resistor. and a flexible contact disposed over the elongated resistor and the conductor taps with a small space normally apart therefrom. A depression of the flexible contact makes an electric connection between the flexible contact and the elongated resistor or between the flexible contact and the conductor tap to sound a tone having the pitch determined by the depression point.

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BACKGROUND OF THE INVENTION The present invention relates to a playing device for an electronic musical instrument, and more particularly to a fingerboard which is a kind of manual device for playing portamento performances and glissando performances selectively.

As is well known, a true portamento effect is realized by a continuous smooth passing from one tone to another by a gradual change of the pitch (tone frequency). While the portamento effect prominently assists in improving the expression of performance given by a musical instrument, a general keyboard musical instrument does not admit of such effect, so that said portamento effect is at the present moment only imitated by the glissando effect which means a scale passage from one tone to another by a stepwise change of the pitch. However, there is a strong demand for a musical instrument capable of displaying a true portamento efiect instead of such imitation. To this end, there has recently been proposed an electronic musical instrument capable of realizing a true portamento effect wherein a tone signal generator consists of the undermentioned variable frequency oscillator and the frequency of tone signals generated by said oscillator is continuously and gradually varied. According to this system, a time constant circuit determining the frequency of signals generated by said variable frequency oscillator used as a tone signal generator includes a variable element, for example, one whose resistor is of a variable type. Namely, a true portamento performance is attempted by continuously changing the resistance of said variable resistor with the resultant variation in the time constant of said time constant circuit and the frequency of tone signals from said oscillator.

Such a variable resistor used in controlling the performance of an electronic musical instrument should be smoothly and quickly varied in the resistance at any time from any desired value to another desired value by a simple operation, so that one operation serves as selection of the tone pitch and as keying of the tone, which generally requires another switching means. However, a musical instrument including a conventional variable resistor of normally closed contact type wherein the slider which is contactually movable on the body of a resistor is shifted in position by fingers can not meet the aforesaid demand, because said slider always contacts the resistor body.

Also in a special case where such a portamento device itself is used as an electronic musicalinstrument it is desired that there can be effected not only the portamento, but also the glissando or the ordinary melody performance with tones having particular pitches in a musical scale. However, an electronic musical instrument including the prior art variable resistor as a means for determining tone pitches can not allow the resistor to be set exactly at a desired value of the resistance, failing to realize a musical scale tone performance like on a conventional keyboard musical instrument. Further, the known electronic musical instrument wherein the tone signal generator consists of a variable frequency oscillator to carry out melody performance includes a solo instrument. With the last-mentioned type, however, the capacity of an element for determining the frequency of signals from said oscillator is set at a value selected from those predetermined through operation of key switches, so that this type has the disadvantage and inconvenience of failing to play the portamento performance. in contrast, the device of the present invention for controllingthe performance of a musical instrument is entirely different in the object and scope from those previously proposed.

' SUMMARY OF THE INVENTION The present invention has been accomplished in view of the aforesaid circumstances to provide an electronic musical instrument capable of realizing both portamento and glissando performances satisfactorily by a simple operation.

The present invention attains the aforesaid object by utilizing means for varying theresistance of a variable resistor constituting an element for determining the frequency of signals from a variable frequency oscillator acting as a tone signal generator for an electronic musical instrument, said means comprising a normally open pressure contact member disposed at a very small distance from the body of an elongated resistor and electrically contacting any desired point of said resistor body only when depressed by fingers and a plurality of conductor taps provided in such a manner that, like said resistor body, they are positioned at a very small distance from said normally open pressure contact member, whereby a group of continuously varying values of resistance is not only obtained from said variable resistor section but also a given value of resistance exactly controlled to a predetermined value can be selected from said conductor taps.

A playing device for an electronic musical instrument including a variable resistor according to the present invention comprises a substantially rectangular base member made of insulating material, a narrow platelike resistor body mounted on the upper surface of said base member in parallel to its longitudinal direction, a plurality of separate conductor strips or taps arranged on said base member at a small space from each other aligned in a row parallel to said resistor body and an elastic, flexible pressure contact member fitted to said base member to cover that surface thereof on which is formed said resistor body, and conductor strips disposed in such a manner that those parts of said pressure contact member which are lined with layers of conductive material face said resistor body and conductor strips or taps at least normally at a predetermined small distance therefrom. When a given part of said pressure contact member is depressed, said conductive material contacts the corresponding part of said resistor body or the corresponding one of said conductor strips or taps which are disposed opposite to said conductive material.

When the depressed point is continuously shifted, a given contact point is similarly moved to another desired point. Accordingly, an electronic musical instrument employing the aforementioned playing device enables a true portamento performance to be realized by depressing that part of said pressure contact member facing said resistor body and continuously changing said depressed part, a melody performance to be affected by depressing that part of said contact member facing a given conductor strip or tap and then selectively changing said depressed part and a glissando performance to be carried out by continuously shifting said depressed part through that portion of said contact member facing said series of conductor strips or taps.

BRIEF EXPLANATION OF THE DRAWINGS FIG. 1 is a perspective view, partly broken away, of a playing device according to an embodiment of the present inventron;

FIG. 2 is an equivalent diagram of the embodiment of FIG.

FIG. 3 is block diagram of the main part of an electronic musical instrument utilizing a playing device according to the embodiment of FIGS. 1 and 2, showing the manner in which said device is operated;

FIG. 4 is a circuit diagram showing the details of the embodiment of FIG. 3;

FIG. 5 shows a modification of a membrane of conductive material acting as a flexible contact conductor included in the variable resistor of the invention;

FIGS. 6 and 7 show a variable resistor according to another embodiment of the invention corresponding to that of FIGS. 1 and 2; and

FIG. 8 represents in correspondence to FIG. 3 a block diagram of the main part of an electronic musical instrument utilizing a playing device according to the embodiment of FIGS. 6 and 7, showing the manner in which said embodiment is operated.

DESCRIPTIONOFTHE PREFERRED EMBODIMENTS A fingerboard according to the present invention so designed as to determine the frequency of tone signals from a variable frequency oscillator acting as a tone signal generator so as to play music on an electronic musical instrument comprises, as shown in FIG. 1, an elastic, flexible pressure contact member 16 fitted to a base member 11 in such a manner that first and second membranes l4 and made of conductive material with which said pressure contact member is partly lined face a resistor body 12 and a plurality of conductor strips or taps 13a, 13b, 13c disposed on said base member 11 normally at a small distance therefrom. There will now be described the fingerboard 10 by reference to the accompanying drawings. The base member 11 is made of insulating material, for example, wood or synthetic resin in the shape of an elongated substantial rectangle. 0n the upper surface 17 of the base member 11 is formed, along its longitudinal direction, a wide and shallow depression assuming a substantially inverted trapezoidal shape. The base member 11 is fabricated in advance in such a manner that the thickness of its central part extending in its longitudinal direction is smaller than that of both edge portions extending in the same direction. The reason is that when there is stretched, as later described, said pressure contact member 16 over said base member 11 in a manner to cover its upper surface, it is desired to allow a space between the central part ofsaid upper surface and the pressure contact member 16. Along the central or thin part of the upper surface of said base member 11 are cut out in advance two

parallel grooves

18a and 18b at a predetermined space from each other. Throughout between said two

grooves

18a and 18b is formed a narrow gently bulging portion.

Into the desired one (indicated at 18a) of said two grooves of the base member 11 shaped as described above, is fitted a narrow rectangular strip of said resistor body 12 in such a manner that its upper half is exposed above said groove 18a and its lower half is embedded therein. in the other groove 18b are disposed, as illustrated, a plurality of rectangular conductor strips or taps 13a, 13b, 13c spaced apart from each other and contiguously aligned in a row parallel to and by the resistor body 12, and spaced apart at substantially the same space from said conductive membrane as is the case with said resistor body 12. The conductor strips or

taps

13a, 13b, 130 ...are respectively connected, as indicated, to different specified points of said resistor body 12 by means of connection conductors a, 20b, 20c passing below the bottom of said base member 11. FIG. 2 is an equivalent diagram clearly defining the relationship of said resistor body 12, conductor strips or

taps

13a, 13b, 13c and connection conductors 20a, 20b, 20c in the preceding case said resistor body 12 assumes a narrow rectangular form, but may consist of a fine resistance wire wound like a solenoid.

The pressure contact member 16 is stretched across both thick edge portions of the upper surface 17 of said base member 11 to cover said surface 17 in a manner to be set a little apart from said resistor body 12 and conductor strips or taps 13a, l3b,13c formed thereon. Said pressure contact member 16 is practically prepared from, for example, cloth or a suitable type of plastics material. Those parts of said contact member 16 which face said resistor body 12 and conductor strips or taps are linedwith said

membranes

14 and 15 made of conductive material which are prepared, for example, by bonding a metal foil or conductive rubber film or vapor depositing a metal layer. if, in this case, said base member 11 is fabricated by properly defining the difi'erence between the height of its both thick edge portions and that of its central portion, then there will be allowed a desired space between said conductive metal membrane on one side and said resistor body 12 and said plurality of conductor strips or taps on the other. The width of said space is limited to such an extent, for example, about 1 to 2mm. as will allow said

conductive metal membrane

14 or 15 electrically to contact said resistor body 12 or conductor strips or taps 13a, 13b, 13c respectively at a given part of said pressure contact member 16 when it is depressed by fingers or the like. Said narrow slightly bulging portion 19 formed throughout between said grooves l8aand 18b reliably prevents the playing of an undesired tone such as when the desired point of that portion of the pressure contact member 16 which is lined with conductive metal membrane 14 is depressed for contact with the resistor body 12, another conductive metal membrane 15 might perchance touch any of the corresponding conductor strips or taps 13a, 13b, 13c

The fingerboard 10 having the aforementioned arrangement constitutes, as shown in FIG. 3, an element for defining the frequency of signals from a variable frequency oscillator acting as a tone signal generator for an electronic musical instrument and is suitably used as a device for controlling the performance of such musical instrument by properly regulating said frequency. In this case, the fingerboard 10 is employed, as illustrated in FIG. 3, as a sort of variable DC voltage generator. Both ends of the said resistor body 12 are inserted between both terminals of a DC power source 21. Said

conductive metal membranes

14 and 15 are jointly connected through a common line to the control terminal of a tone signal generator 22 consisting of a variable frequency oscillator.

Accordingly, when the desired point of that portion of said pressure contact member 16 which is lined with said conductive metal membrane 14 is depressed by fingers to cause said membrane 14 electrically to contact the desired point of said resistor body 12, then said membrane 14 is impressed with a voltage corresponding to that part of aid membrane 14 at which it contacts said resistor body 12. Thus said variable frequency oscillator 22 receives a DC voltage impressed on said conductive metal membrane 14, namely a voltage which is drawn out of said fingerboard 10 and varies in value with said depressed point. Said fingerboard 10 is used as an element for defining the frequency of signals from said variable frequency oscillator, for example, by the method as later described with reference to FIG. 4. When the depressed part of said pressure contact member 16, that is, the contact point between said conductive metal membrane 14 and resistor body 12 is continuously shifted, said variable frequency oscillator 22 is impressed with a DC voltage which also varies continuously and smoothly, allowing the frequency of signals from said oscillator to be changed in a similar gradual manner. When the tone signals whose frequency varies continuously and smoothly are transmitted to an amplifier through the desired one of the tone coloring circuits included and a loudspeaker is actuated by the tone signals thus amplified, then there is realized a portamento performance.

Where said fingerboard 10 is employed in the indicated manner, the conductor strips or taps 13a, 13b, 13c are connected, as described above, through the connection conductors 20a, 20b, 20c to the specified parts of said resistor body 12 arranged at a predetermined space from each other, thus serving as leadout taps with respect to said resistor body 12. Accordingly, each of said conductor strips or taps 13a, 13b and is supplied with a DC voltage which is regulated exactly to one of the predetermined particular values (for the chromatic scale tones) corresponding to the parts of said resistor body 12 contacted by said conductor strips or taps through said connection conductors 20a20b, 20c When the desired point of the second conductive metal membrane 15 is depressed from above said pressurecontact member 16 for selective contact with the corresponding one of said plurality of conductor strips or taps 13a, 13b, 13c then there is drawn out of said variable resistor the DC voltage which was impressed on the selectively contacted conductor strip or tap, said voltage being used as an element for defining the frequency of signals from said variable frequency oscillator 22. When the depressed part of said pressure contact member 16 is continuously shifted, said variable frequency oscillator 22 is impressed with a DC voltage which varies stepwisely, thereby enabling the frequency of signals from said oscillator to be changed in a similar stepwise manner. When the tone signals whose frequency stepwisely and chromatically varies are conducted to an amplifier through the desired one of the tone coloring circuits included and a loudspeaker is actuated by the tone signals thus amplified, then there is obtained a glissando performance which was used by the prior art keyboard musical instrument as an imitation of a portamento performance. Where the depressed point of said pressure contact member 16 is shifted discontinuously upward and downward, said variable frequency oscillator 22 is supplied with a DC voltage which also varies discontinuously, causing the frequency of I signals from said oscillator 22 to be changed in a similar toand-fro manner. When tone signals whose frequency varies discontinuously in accordance with the depressed part of said pressure contact member 16 are supplied, as in the previous case, to actuate a loudspeaker, then there are obtained any desired melodies with musical tones hose pitch varies discontinuously in accordance with the selection of the depressed points of said pressure contact member 16, namely, accurate musical scale tones.

FIG. 4 is a concrete circuit diagram of an electronic musical instrument including the aforesaid playing device consisting of the fingerboard of the present invention illustrated in FIG. 3. Both ends of the variable resistor 12 of the fingerboard 10 are connected between a grounded positive DC source terminal 23 and a negative DC source terminal 24 via respective semivariable resistors. Also between said terminals 23 and 24 is connected a variable frequency oscillator 25 constituting a tone signal generator 22. SAid variable frequency oscillator 25 consists of an astable multivibrator wherein the time constant circuit acting as an element for defining the frequency of signals from said oscillator 25 has

field efiect transistors

32 and 33 connected in series so as to constitute the resistance thereof. Said variable frequency oscillator 25 is prepared in the following manner. Namely, there are used two NPN-type transistors 26 and 27 connected by a common emitter, the collector terminals of which are each connected to said positive DC source terminal 23 through the respective resistors. The base terminals of said transistors 26 and 27 are connected to the collector terminal of another transistor through capacitors 28 and 29 respectively, and further to said positive DC source terminal 23, as shown through resistors 30 and 31, and the source and drain terminals of

FETs

32 and 33. The gate terminal of each (field efiect transistors) PET is connected to the common contact 35 of the first and second conductive membranes 14 and of said fingerboard 10 through a temporary memory circuit 34 consisting of a resistor 34a and capacitor 34b. Thus is prepared said variable frequency oscillator 25. Further, to both ends of the resistor body 12 of said fingerboard l0 is parallel connected a circuit involving two capacitors 36 and 37 connected in series, the contact of said capacitors 36 and 37 being connected to the collector terminal of said transistor 26.

When the desired part of said pressure contact member 161 disposed above said fingerboard 10 having the aforementioned circuit arrangement is depressed for contact with said resistor body 12 or any of a plurality of conductor strips or taps 13a, 13b, 13c arranged in a row, then there is obtained from said

conductive membrane

14 or 15, that is, said fingerboard l0 a DC voltage having a magnitude corresponding to the depressed part as described in connection with FIG. 3. Said variable DC voltage is impressed through said memory circuit 34 to the gate terminals of said two FETs to turn them "on, thus controlling the impedance across the drain and source tenninals thereof to a predetermining value corresponding to said gate voltage. The conduction of said FET's allows said astable multivibrator or variable frequency oscillator 25 to start oscillation at a desired musical tone frequency, thereby generating tone signals hose frequency is regulated by the time constant of the time constant circuits consisting of capacitors 28 and 29, resistors 30 and 31 and

FETs

32 and 33 respectively.

Said tone signals are conducted to a frequency dividing circuit 38 consisting of two cascade connected flip-flop circuits. By said frequency dividing circuit 38 are formed tone signals, one group of which has a pitch 0] octave lower and the other group of which has a pitch 2 octaves lower, than the first-mentioned tone signals. These two groups of tone signals are composed and conducted to the input terminal 40 of a switching circuit 39. On the other hand, the tone signals generated by said variable frequency oscillator 25 are fed back to both ends of the resistor body 12 of said fingerboard 10 through said capacitors 36 and 37. Accordingly, the voltage obtained from said fingerboard 10 due to the aforesaid depression of said pressure contact member contains an AC component having a fixed amplitude regardless of the depressed point. Only said AC component involved in the pulses drawn out of said variable resistor is supplied through a capacitor 41 to a circuit 42 actuating said switching circuit 39 to control the keying of tone signals supplied to said switching circuit 39. While the pulses from said variable resistor 12 are supplied to the'gate terminals of said

FETs

32 and 33 as an element for defining the frequency of signals from said variable frequency oscillator 25, the aforesaid AC component is shunted by the capacitor 3412 involved in said memory circuit 34, allowing only the DC component to be supplied to said gate terminal. The AC signals thus sent to said actuating circuit 42 are converted thereby to a DC voltage, and, after being suitably amplified, conducted to the keying terminal 43 of said switching circuit 39. This circuit 39 brings the tone signals received by its input terminal 40 to its output side only when there is impressed a DC voltage on said keying terminal 43. The tone signals passing through said switching circuit 39 are forwarded through a tone coloring circuit and amplifier (not shown) to a loudspeaker to actuate it. Thus the desired musical tones are produced from the loudspeaker. As described in connection with FIG. 3, when the part of said first or second

conductive metal membrane

14 or 15 which is depressed from above said pressure contact member 16 is shifted, then the DC component of the voltage drawn out of said variable resistor 12 also varies with said depressed point, though the AC component remains unchanged in amplitude. Thus the DC voltage varying with said depressed point is supplied to the gate terminal of said

F ETs

32 and 33, causing the impedance of these F ETs and in consequence the time constant of said time constant circuit to vary with said depressed point with the resultant change in the frequency of signals from said oscillator 25. As mentioned above, the shifting of said depressed point or the control of the performance of an electronic musical instrument allows those tone signals to be generated whose pitch varies with said depressed point, thereby realizing the portamento, glissando or melody performance.

in the foregoing embodiment, the FET consisted of an enhancement type, but it will be apparent that the same effect will also be obtained by a depletion type. it will be noted, however, that with the FET of enhancement type, the variable frequency oscillator consists of an emergency tone signal generator, whereas with PE! of depletion type, said oscillator is of a normally oscillating type. Substitution of an ordinary transistor for said FET will obviously display substantially the same effect.

In the aforesaid embodiment said variable resistor is employed as a sort of variable DC voltage generator. However, if said resistor body 12 is chosen to have a suitable rated capacity, said variable resistor may be directly connected to the time constant circuit for defining the frequency of signals from said variable frequency oscillator, thereby controlling the time constant of said time constant circuit and in consequence the frequency of oscillated signals directly by the variation of said resistance.

In the above-mentioned case, the second conductive membrane 15 to be used with a plurality of conductor strips or taps 13a, 13b, 13c arranged in a row to effect a musical scale performance consists of a single narrow rectangular piece formed on the prescribed surface of said pressure contact member 16. However, said conductive membrane 15 may be so prepared as to involve a nonconductive portion at those parts thereof which face the intervals between the adjacent onesof said plurality of conductor strips or taps. Namely, said membrane 15 may assume, for example, a lattice form indicated by numeral 44 of FIG. 5. This is for the reason that when a given point on that part of said pressure contact member 16 which is lined with second conductive membrane 15 is depressed by contact with the corresponding one of said plurality of conductor strips or taps, the aforementioned device may reliably prevent the occurrence of an undesirable event that a conductor strip or tap adjacent to said depressed one might perchance touch said second conductive membrane 15. The above-mentioned method will enable a melody performance to be accurately carried out and moreover a glissando performance to be realized smoothly without any harmful effect.

In the above-mentioned embodiment, a plurality of conductor strips or taps 13a, 13b, 13c arranged in a row for a musical scale performance are connected to the specified parts of said resistor body 12 disposed at a prescribed space from each other through connection conductors 20a 20b 20c so as to serve as taps for drawing a voltage out of said resistor body 12. However, where the performance controlling device of the present invention is incorporated in an ordinary keyboard electronic musical instrument, it is possible electrically to disconnect said resistor body 12 from said plurality of conductor strips or taps 13a, 13b 13c and so arrange them as to control separate tone signal generators.

In this case, said plurality of conductor strips or taps 13a, 13b, 13c are fitted, as shown in FIGS. 6 and 7, with

terminals

45a, 45b, 45c respectively instead of connection conductors 20a, 20b, 20c indicated in FIGS. 1 and "2. Said

terminals

45a, 45b and 450 are respectively connected, as shown in FIG. 8, to the tone signal take out lines 47a, 47b 47c associated with the tones having the corresponding pitches which are produced by the tone signal generator of a keyboard electronic musical instrument which is separately provided from said tone signal generator 22 consisting of the aforesaid variable frequency oscillator 25. Said second conductive metal membrane 15 is directly connected to the input side of the tone coloring circuit (not shown) of said keyboard electronic musical instrument, namely, to the output side of the latter tone signal generator 22. On the other hand, said resistor body 12 and said first conductive metal membrane 14 facing it are connected, as in FIG. 3, in a manner to control the frequency of signals from said tone signal generator 22 consisting of said variable frequency oscillator 25. The output side of said tone signal generator 22 is connected, like said second conductive metal membrane 15, to the input side of said tone coloring circuit. When arranged as described above, the conductor strips or taps 13a, 13b 13c of said fingerboard l and said second conductive metal membrane 15 jointly constitute a normally open single pole multicontact switch and act as key switches for tone signals from the aforementioned tone signal generator 46, together with those operated by the keyboards of a keyboard electronic musical instrument. When a given point of that part of said pressure contact member l6 which is lined with said second conductive metal membrane 15 is depressed, then there is drawn out of said tone signal generator 46 a tone signal having a pitch corresponding to said depressed point. This tone signal is conducted to said tone coloring circuit and then through an amplifier (not shown) to a loudspeaker to actuate it. When said depressed point is shifted as described in connection with the embodiment of FIG. 3, there are similarly realized the glissando and melody performances. Said resistor body 12 and the corresponding first conductive metal membrane 1 8 perform the same action as in the embodiment of FIG. 3, allowing a portamento performance to be similarly realized by the aforesaid depressing operation. though detailed description is omitted, it will be apparent that the embodiment of FIGS. 6 and 7 can display the same effect as the preceding one.

As clearly understood from the foregoing description, the fingerboard of the present invention used for playing music on an electronic musical instrument is of a normally open contact type and has its resistor body provided with a plurality of taps.

Accordingly, when the desired point of an elastic, flexible pressure contact member is depressed by finger, then a group of continuously and smoothly varying values of resistance is obtained and also a given value of resistance can be selected at any time from a group of sequentially and stepwise varying values of resistance. Further, the mere shifting of said depressed point enables said selected value of resistance to be sequentially varied either smoothly or stepwise. Also, where required, said variable resistor may be formed into a combination of the aforesaid resistor body capable of continuously and smoothly varying values of resistance .from a given value to another desired value at any time and a plurality of normally open contacts acting as a key switch. With an electronic musical instrument involving the fingerboard of the present invention as a playing device or manual of the instrument, the continuous shifting of the finger-depressed point of a fingerboard surface consisting of said pressure contact member immediately realizes at any time portamento and glissando performances starting at any pitch, and the selective shifting of said depressed point enables a melody performance. Namely, the present invention provides an electronic musical instrument capable of conducting portamento, glissando and musical scale melody performances.

What is claimed is:

1. A playing device for an electronic musical instrument comprising a substantially rectangular base member (11) made of insulating material, said base member having a longitudinal surface (17), a narrow strip of a resistor body (12) formed on said surface in said longitudinal direction, a plurality of conductor strips (13a, 13b) arranged at a predetermined distance from each other in a row substantially parallel to said resistor body, and an elastic, flexible pressure contact member (16) forming a fingerboard fitted to said base member materialso as to cover said surface in such a manner that part of said contact member which is lined with layers of conductive material normally faces said resistor body and conductor strips at a prescribed small distance therefrom and being so adapted and disposed that when a given point of that part of said fingerboard which faces said resistor body is depressed and said depressed point on said fingerboard is continuously shifted, there is realized a portamento performance and, when given point of that part of said fingerboard which faces said conduct or strips is depressed and said depressed point is varied in a prescribed order, then there is obtained a melody performance and, when, said depressed point of said fingerboard. is continuously shifted over said conductor strips, then there is effected a glissando performance.

2. The device according to claim 1, including a tone generator variable frequency oscillator wherein said plurality of conductor strips are connected to predetermined different parts of said resistor body and serve as tapping terminals for said resistor body, said resistor body being coupled to said oscillator so that the depressing of said fingerboard on said conductor strips stepwise controls the frequency of signals generated by said variable frequency oscillator.

3. The device according to claim 1, including a tone generator variable frequency oscillator, said resistor body being cou pled thereto, said plurality of conductor strips being electrically disconnected from said resistor body and are each provided with a terminal and each act as a normally open single pole multicontact switch in cooperation with said pressure contact member fingerboard, said resistor body serving as a normally open variable resistor in cooperation with said pressure contact member fingerboard, said single pole multicontact switch being used as a key switch for said tone signal generator and said variable resistor acts as means for controlling the frequency of tone signals from said variable frequency oscillator.

4. The device according to claim 1, wherein said pressure contact member is made of insulating material and lined with two narrow rectangular membranes of conductive material spaced from each other in a manner to face said resistor body and plurality of conductor strips.

rectangular membrane of conductive material formed on the inside of said pressure contact member so as to face said plurality of conductor strips has a nonconductive portion at those parts thereof which face spaces between adjacent conductor strips.

t. ll I! l

Claims

1. A playing device for an electronic musical instrument comprising a substantially rectangular base member (11) made of insulating material, said base member having a longitudinal surface (17), a narrow strip of a resistor body (12) formed on said surface in said longitudinal direction, a plurality of conductor strips (13a, 13b) arranged at a predetermined distance from each other in a row substantially parallel to said resistor body, and an elastic, flexible pressure contact member (16) forming a fingerboard fitted to said base member material so as to cover said surface in such a manner that part of said contact member which is lined with layers of conductive material normally faces said resistor body and conductor strips at a prescribed small distance therefrom and being so adapted and disposed that when a given point of that part of said fingerboard which faces said resistor body is depressed and said depressed point on said fingerboard is continuously shifted, there is realized a portamento performance and, when a given point of that part of said fingerboard which faces said conductor strips is depressed and said depressed point is varied in a prescribed order, then there is obtained a melody performance and, when said depressed point of said fingerboard is continuously shifted over said conductor strips, then there is effected a glissando performance.

3. The device according to claim 1, including a tone generator variable frequency oscillator, said resistor body being coupled thereto, said plurality of conductor strips being electrically disconnected from said resistor body and are each provided with a terminal and each act as a normally open single pole multicontact switch in cooperation with said pressure contact member fingerboard, said resistor body serving as a normally open variable resistor in cooperation with said pressure contact member fingerboard, said single pole multicontact switch being used as a key switch for said tone signal generator and said variable resistor acts as means for controlling the frequency of tone signals from said variable frequency oscillator.

5. The device according to claim 1, wherein said resistor body and conductor strips are disposed in a depression formed at the central part of the prescribed surface of said base member, and said elastic, flexible pressure contact member is stretched across both ends of said prescribed surface.

6. The device according to claim 4, wherein said narrow rectangular membrane of cOnductive material formed on the inside of said pressure contact member so as to face said plurality of conductor strips has a nonconductive portion at those parts thereof which face spaces between adjacent conductor strips.