DE10147710B4 - Measurements on a stringed instrument - Google Patents

Abstract

Method for operating a stringed instrument (1),
characterized,
that for each string is determined individually, independently of the other strings,
which of the strings (20) of the stringed instrument is struck or deleted at what time, and
whether the attack or strike is an up or down.

Description

The The present invention relates to an electronic device for Improvement of the sound of stringed instruments.

For one Electric guitarists (electric guitarists) it is common to the guitar sound through Effect devices (such as Chorus, reverb, distortion or generally by means of functions in one Synthesizer) to vary or beautify. Not always with them To play effects these effects can be quickly switched on and off. This requirement also applies to sound enhancements on other stringed instruments.

Usually become electronic effect devices like digital guitar synthesizers via footswitch or footswitches switched on or off or the desired sound variations selected. One can z. B. beautify a guitar solo by effects by using a footswitch operated before and after the solo.

The Turning on and off effects units such as z. B. a synthesizer over footswitch works relatively slowly (not less than 50 ms). Impossible it, via footswitch Tones with targeted for different effects, e.g. fast consecutive, to sound.

task The invention is therefore to provide a method and a device, which allow sounds targeted with different effects, e.g. fast consecutive, to sound.

These The object is achieved by the inventions according to the independent claims 1, 16, 17, 18 and 25 solved. Advantageous developments of the invention are characterized in the subclaims.

Usually will the strings of a stringed instrument by means of a plectrum or other aids such as coins or struck with a hand or finger or painted with a bow.

The asked task is solved by the stop time and the direction of attack (up or down) Tee) of the string or the plectrum or other aids or hand or finger or bow as "stroke / direction information" on electronic Detected ways and both signals are used together to control effects units. This stop / direction information is then arbitrary Tax tasks available. To the Example can severed tones be provided with distortion effect and open tones the chorus effect get assigned. The guitarist chooses so on the direction of attack z. B. the Plektrons the effect of the sound to be played and can therefore even fast played, consecutive tones or Provide chords with different, individual effects, if the stop detects itself and its direction separately for each tone and processed electronically.

The Information which in the direction of movement of the string after a Include premium or discount as dynamic motor conditions are, can thus specifically used for sound improvement. This will be mechanical Switch as foot switch etc. make future unnecessary. modern Guitar Synthesizer do not currently offer the possibility, to give a tee with a different sound effect than one Surcharge.

The basic principle of the detection of the below described Stop / direction information is based on the combination of a simple electric switch and, in a first advantageous embodiment, a measuring device based on Faraday's law of induction. The switch is used to determine the timing of the string stop itself to recognize. The switch should be closed when the plectrum touched the string. To do this the plectrum and the string are electrically conductive. The measurement an induction voltage in the struck string is used to the Direction of the movement caused by the plectrum (deflection from the rest position) of the string. With this device the direction information is automatically and very quickly recorded, without it being a mechanical switch and its operation through the musician needs, as it currently still state of the art is.

In a second advantageous embodiment, the direction detection by measuring the voltage induced in the magnetic field in the coil of a usual Pickup, which arranged laterally offset below the string is made.

In a third, advantageous embodiment, the direction detection by means of a special design of an electromagnetic pickup with two oppositely wound coils connected in series under each string ensures being able to handle this special design like a standard pickup is. This has the advantage that musicians with the use of standard, electromagnetic Cartridges are already familiar. The timing of the attack can with the help of the signal of a conventional pickup or by means of the electrically conductive Plektrons be determined.

In a fourth, advantageous embodiment, the direction of movement the string by ultrasonic or microwave radar on the hand determined by the musician or on the plectrum or other means become. This has the advantage that light, in particular miniaturized Components can be used.

In further advantageous embodiments the direction of movement of the string through the analysis of video recordings or by means of photoelectric sensors or strain gauges in the plectrum or using piezo pressure sensors in the bridge or saddle of the stringed instrument or detected in the plectrum.

In many embodiments the string may be electrically conductive or non-conductive, causing the scope of the invention from electrical to acoustic Extended string instruments.

The Problem of stop detection, d. H. the time of the attack alone, is already solved according to the current state of the art; without a stop detection would a digital guitar synthesizer do not know at what time played sound are converted into a digital control signal should. Except the more detailed below described new possibilities of Attack detection can always be on the known possibilities back be grasped.

at the known possibilities The striker will detect the movement of the string with a standard pickup converted into an electrical voltage signal. In one of these known design convert pickups the mechanical vibrations of struck strings by means of so-called Stratocaster in electrical alternating voltages around. Stratocaster consist of electrically conductive coils used on older models around bar magnets, in recent times wrapped around soft iron pins, with bar-shaped Ferrite magnets on the bottom. The field lines of the magnets flow through the Strings on a part of their length. In the rest position of the strings, the magnetic flux is constant. Emotional the string after a stop from the rest position, deforms because of the electrical conductivity the string of spatial Course of the field lines. This changes the magnetic flux through the coil. From one with one Therefore, certain frequency vibrating string will be in the coil one AC voltage of the same frequency induced. The amplitude of the voltage the known pickup hangs off the strength the stop (the amount of deflection from the rest position of the string), their electrical conductivity and the distance between string and magnetic pole. Known pickups, that work with this principle, generate voltages with amplitudes in the range of a few hundred millivolts. The signals are each reinforced separately and rectified and serve as inputs to one noninverting Schmitt trigger. Exceed the rectified ones Signals a predetermined amplitude, provides the output of the Triggers for each input signal is an associated one (High level) output signal, what the timing of each stop is detected individually. With hexaphonic pickups, this stop detection for every String to be made separately.

In another version from known pickups use these instead of coils and Magnets rather piezo elements, which are built into the bridge of the guitar are. The bridge is a vertical small board on the top of the stringed instrument, on which the strings rest.

For every string is a separate piezo element used in the respective web segment. Each piezo element is cabled separately. The connecting cables can either be connected together, or they will continue separately to to send the signal of each string to a guitar synthesizer. Furthermore, can Piezo elements also in the bridge or the saddle of the guitar. The saddle is the attached to the upper end of the fretboard of stringed instruments Cross bar on which the strings rest. In such piezo pickups can be electrically conductive or non-conductive strings are used.

In The present invention is compared to the known possibilities However, the detection of the stop time is a particularly simple Concept for detecting attacks described. Because the plectrum itself is electrically conductive and electrically connected to a voltage source is conductively connected, flows as soon as the plectrum contacts the electrically conductive string, via plectrum and string towards the mass a current pulse, which is the time of Clearly defined.

For the subsequent measurement of the direction of movement of the page by means of the new, advantageous first embodiment using the induction principle, the string is, as in known embodiments of conventional pickups, in a magnetic field. Since the string is deflected by the stop from its rest position, it represents a magnetic field moving conductor, in which an induction current is caused. On the internal resistance of the string therefore produces an electrical voltage, the polarity of this voltage depends on the direction of movement of the string With the help of a simple evaluation, which detects this polarity, you can therefore the direction of movement of the string against the Resting position and thus determine the direction of impact of the Plectron. If you measure the direction of movement immediately after the timing of the string stops to the maximum deflection of the string, you get the desired, full stop / direction information. Each string stop is assigned exactly one direction of movement.

Compared to the known pickups, which only the attack time, the frequency and Amplitude detect, here is also the direction of attack by the Identification of the polarity of the induction voltage identified.

Although in the published patent application DE 199 17 757 A1 already described a sampling of string vibrations of electric musical instruments in which electrically conductive strings oscillate in a magnetic field and the voltage induced in them is fed to any signal conditioners, signal amplifiers or converters. There, however, the signals are not used to gain information about the direction of a particular Plektronanschlags so that the musician can act by means of him in exactly this stop made arbitrary determination of the attack direction artistically-shaping the sound of exactly this attack. The signals are to be processed there only technically, without the design of the sound beautification by directional orientation of each individual, individual attack by the musician is targeted.

Next is from the DE 195 28 051 A1 It is known that the 6 analog outputs of a guitar can be fed to 6 separate distortion and the distortion can be controlled separately. This means that the tones or tone sequences produced on individual strings, although in each case alike, ie with the same electronic tool, for. B. by means of distortion, can be edited. However, this publication also lacks the doctrine of how each individual tone of a tone sequence could be accessed individually by a stop / direction recognition to formally shape that particular tone or, as with successive tones of a string, each note versus a preceding or succeeding one Sound different, z. B. by distortion or chorus deformed who could.

Next is from the DE 199 13 249 A1 known that by a sensor built into a plectrum, z. As a thin film sensor, the parameters of an effect device can be controlled by finger pressure. Again, the teaching is limited by all the sounds generated on a string with the same electronic tool, namely the effect device, z. As a distortion, can be deformed. An individual deformation of individual, consecutive tones by different effect devices, is thus not possible.

In the US 5,005,461 describes an e-guitar synthesizer equipped with many functions, which can use a complicated methodology to conclude an up or down on the instrument, but only on the premise that a discount is carried out with greater force than a premium. Furthermore, this synthesizer requires this ever a measurement of two broken strings. A usable control signal for controlling any separate effect devices is not generated. With this complicated constructed synthesizer a real-time effect control by playing only one string is not possible, accordingly, a control by playing with change impact on only one string is not feasible.

Another path taken led to a real-time effect circuit ( US 4,235,144 ). In this case, circuits via a conductive Plektronseite or a subdivided conductive Plektronseite or a special Plektronkonstruktion, the Plektronober- and lower part are largely isolated from each other, but between the abutting tips of Plektronober- and lower part a small air gap acts as insulation. Due to the pressure on the plectrum tip at the string stop, the two plectrum tip portions which are only isolated by the air gap come into contact, and thus a signal during triggering of the contact. An attack direction detection is not possible with this arrangement.

In No. 4,348,930, the pickup pickup was varied, usually with a magnetic core and a coil for each string perpendicular to instrument surface is installed under each string and only the vibrations of one Use string that is perpendicular to the instrument surface. In an arrangement of magnetic core and coil in a pick-up detects two vibration levels of the strings, which are perpendicular to each other, but with an angle of 45 ° to instrument surface are positioned. This results in a different sound quality. A Attack direction detection of up and down is not possible.

In the US 5 591 931 A With the aid of a computer with an analogue control input, a guitar synthesizer is described which transmits the analogue signals to the stereo input of a sound card of a PC with the help of a hexaphonic pickup and a modulation method. Thanks to the modulation method, the signals of the individual strings can be separated again and the pitch determined by the computer software. A discount or discount is ever not.

In several executable examples, the details of the stop / direction detection and an associated digital circuit for control tasks are described below with reference to the schematic 1 to 10 be explained in more detail. In the figures, recurring components are each provided with the same reference numerals.

in the single shows:

1 the electrically conductive plectrum with the electrically contacted, isolated power cable,

2 the diagram of the attack timing detection, for example for the low and the high e-string (first index e),

3 the digital processing (normalization and time delay) according to the arrangement 2 obtained timing signals,

4 schematically the arrangement of the magnet on the body of the electric guitar (contour line) for the stop direction detection,

5 the block diagram of the stop direction detection,

6a a conventional electromagnetic pickup,

6b the laterally offset mounting manner of a conventional electromagnetic pickup, and

6c the special design of an electromagnetic pickup,

7 the device for direction detection of Plectron movement by means of ultrasonic or microwave Doppler effect measurement,

8th the contiguous digital circuitry of a beat timing and direction detection for a string,

9 the extension of the digital circuit 8th on the stop timing and direction detection of two strings and

10 the extension of the digital circuit according to the 8th and 9 for stop / direction detection of a four-stringed stringed instrument.

recognition of the moment of impact

The following will be on 1 Referenced. In one embodiment, the musician holds an electrically conductive plectrum 10 in the hand, to which a power cable 11 electrically contacted. The cable leads to a voltage source (not shown), which has a maximum voltage of z. B. Ub = 5V provides. The power supply can be realized for example by a built-in guitar battery, the negative terminal of the battery is connected to the ground terminal of the guitar. The electrically conductive plectrum 10 is over the power cable 11 connected to the positive pole of this Bat terie (not shown). The guitar strings (not shown) must be electrically conductive for this embodiment of the stop detection.

In the preferred, simplest embodiment, the pick is 10 built up homogeneously and consists of metal. That's the cable 11 at the point 12 soldered as it is in 1 you can see. The string (not shown) goes with the top 13 of the plectrum 10 struck.

Touches the electrically conductive plectrum with its tip 13 When closing the electrically conductive string, this is the closing of an electrical contact (switch). About the internal resistance of the string builds during the mechanical contact between Plectron 10 and string (not shown) have a voltage U (t). In this way, the digital information is "stop yes / no?" to disposal.

The The goal is to get a stop detection for each string separately. For the e-, a-, d-, g-, h-strings and the high e-string of the guitar should be added a separate voltage pulse U (t) can be obtained. Because at one Electric guitar usually the land grounded and conductive with all 6 Strings is connected, receives it is easy to separate no separately evaluable voltage signals per String. The strings have to So be electrically isolated from the bridge. The jetty is going to do this made of an electrical non-conductor.

So that a stretched string does not slip through the bridge, the string is threaded through a hole in the bridge when stringing, with a so-called ball end at the end of the string. This ball end is bigger than the hole; In this way, the slippage of the string end is prevented. This ball end is electrically connected to the string. In a first embodiment may be at the ball end of the string, a resistance z. B. brazed and the other side of this resistor are connected via a power cable to the ground terminal of the electric guitar. Alternatively, you can solder the resistor to the saddle, where on the one hand the saddle rider is isolated from the bridge, on the other hand there is a conductive connection at the contact point of the string on the saddle. This applies to all 6 strings of the guitar.

The following will be on 2 Referenced. With open switch, ie as long as the plectrum z. If, for example, the low e-string is not touched, then the "signal output" of this string is UE (t) = 0, ie UE supplies the temporally constant low level for the subsequent signal processing Thus, in this embodiment, UE (t) = Ub = 5V is a short-term high level signal for the duration of the attack (a few milliseconds), and the same applies to each of the other strings with the signal output associated with the respective string.

2 shows as an example the resistances 22 and 23 the deep e-string 20 and high e-string 21 and the signal outputs Ue, t (t) and Ue, h (t) of the deep (second index t) and high (second index h) e strings 20 respectively. 21 , The resistors and signal outputs of the a, d, g, and h strings are for the sake of clarity in FIG 2 not marked and are in the range of dotted lines. Next it is in 2 just one and the same conductive plectrum 10 , with which each of the 6 strings can be struck. The broken circles 24 in this figure schematically represent the contact between electrically conductive Plectron 10 and electrically conductive string 20 or 21 represents.

To the circuit in 2 To make it absolutely functionally reliable, a non-inverting Schmitt trigger (not shown) can be connected to each signal output, which ensures the clear distinction between high and low level signals.

So that the short-term signals Ue, t (t) or Ue, h (t) off 2 to be technically usable for detection of attacks, they must be normalized and time-delayed, as shown in 3 is shown.

• 1. Ein Monoflop 30 erzeugt aus jedem Anschlagssignal, hier als Beispiel Ue,t(t), einen Impuls mit definierter Impulsdauer. Dazu wird der Impuls Ue,t(t) zunächst durch einen Normierer 32 normiert. Anschließend wird der normierte Puls durch die Hintereinanderschaltung von zwei Invertierern 32, 33 verzögert. Da der mechanische Schalter, bestehend aus dem leitenden Plektron und der leitenden Saite, beim Saitenanschlag prellt, wird ein nicht-nachtriggerbares Monoflop 30 eingesetzt. Daher erhält man bei jedem Anschlag am Ausgang des Monoflops genau einen Impuls mit definierter Impulsdauer. Die Impulsdauer wird so gewählt, dass sie deutlich länger ist als die sehr kurzzeitige Kontaktdauer zwischen Plektron und Saite. Jedoch muss die Impulsdauer viel kürzer sein als das Zeitintervall zwischen zwei Saitenanschlägen des Musikers auf der gleichen Saite.
• 2. Der Impuls am Ausgang des Monoflops 30 wird zeitverzögert an den endgültigen Ausgang der Anschlagerkennung weitergeleitet. Die Bewegungsrichtung der Saite muss mit dem vorangehenden Saitenanschlag und nur mit diesem korreliert werden, damit beide Signale in Koinzidenz auch bei schneller Tonfolge weiterverarbeitet werden können. Hierfür wird die Zeitverzögerung durch eine gerade Anzahl hintereinander-geschalteter Inverter 32 und 33 realisiert, wobei jeder Inverter 32 und 33 durch seine Signallaufzeit zur Zeitverzögerung beiträgt.

This further processing is done in two steps:

• 1. A monoflop 30 generates from each stop signal, here as example Ue, t (t), a pulse with a defined pulse duration. For this purpose, the pulse Ue, t (t) is first by a normalizer 32 normalized. Subsequently, the normalized pulse by the series connection of two inverters 32 . 33 delayed. Since the mechanical switch, consisting of the conductive plectrum and the conductive string, bounces off the string stop, becomes a non-retriggerable monoflop 30 used. Therefore, at each stop at the output of the monoflop, exactly one pulse with a defined pulse duration is obtained. The pulse duration is chosen so that it is much longer than the very short contact time between the pick and the string. However, the pulse duration must be much shorter than the time interval between two string strikes of the musician on the same string.
• 2. The pulse at the output of the monoflop 30 is forwarded with a time delay to the final output of the stop detection. The direction of movement of the string must be correlated with the preceding string stop and only with this, so that both signals can be further processed in coincidence, even with fast tone sequence. For this purpose, the time delay by an even number of consecutively-connected inverter 32 and 33 realized, each inverter 32 and 33 contributes to the time delay by its signal propagation time.

This processing of the signals for final impact detection 3 must be done electronically separated for all 6 strings.

recognition the direction of movement of the string

swings according to the above First mentioned, advantageous embodiment of the direction detection an electrically conductive string in the magnetic field, then becomes after the Faraday Induction law in the string induced an alternating electrical voltage UP0 (t). This depends the polarity of the electrical AC voltage from the current direction of movement the string off.

An advantageous arrangement of the magnet on the guitar is in 4 shown. The figure schematically shows the contour of the guitar body 1 and the magnet 40 ,

Advantageously, the string 20 , in the example the deep e-string, by means of the plectrum (not shown) at the level of the magnet 40 at the point 46 struck because here both the magnetic field and the deflection of the string 20 have the maximum amount. The voltage pulse UP0 (t) is in the moving in the magnetic field, electrically conductive string 20 caused by electromagnetic induction. The magnet 40 is schematic with its N poles 41 and 42 shown.

To measure the induction voltage, the terminals of a suitable transducer (not shown) with the string 20 at the bridge (not shown) and at the upper end of the string 20 be contacted electrically. If the string moves in

4 in tee-off direction 43 , so UP0 (t) is relative.

To gain a digital piece of information, whether the string is heading down 43 is moved the signal UP0 (t) off 4 as input to an in 5 schematically illustrated inverting comparator 50 used. The comparator 50 Recognizes the sign of the electrical signal UP0 (t) 4 and delivers for a string movement in the strike direction 43 a HIGH level signal. As reference voltage is applied to the non-inverting input of the comparator 50 the value 0V is applied.

If the input signal is negative, the comparator delivers 50 a high level signal, it is positive, provides the comparator 50 a LOW level signal (not shown). Therefore, a high level signal is shown at the output of the comparator 50 that the string (not shown in 5 ) moved in the strike direction.

This information regarding direction detection (impact or strike direction) can not be obtained from the electrical signal of a conventional electromagnetic pickup ( 6a ), if - as usual - it is positioned directly under a string.

The conventional pickup 60 consists of a coil 61 and a magnet 62 , By every movement of the electrically conductive string 20 in the field of the magnet 62 from their rest position 64 a field change is caused which causes the magnetic flux through the coil 61 changes and in the coil 61 induces a voltage. The amount of change in the flux and therefore the amplitude of the coil 61 induced voltage is from the distance 63 between string 20 and coil 61 dependent.

After a stop the string vibrates 20 in all three spatial directions (not shown), initially with high amplitudes in the respective stop direction of the plectrum. Depending on the strength of the attack and the damping, the string oscillates with different high amplitudes in the three spatial directions. Significant for the amplitude of the coil 61 However, induced stress are only transversal string vibrations, ie string movements perpendicular and parallel to the surface of the guitar body (not shown) or parallel or perpendicular to the coil axis 66 ,

Under these two transverse directions of movement, the influence of the deflection dominates parallel to the coil axis 66 , ie perpendicular to the guitar body, to the level of the amplitude of the induced voltage, because a deflection in this direction with a change 65 of the distance 63 between the string 20 and the coil 61 or the magnet 62 , measured parallel to the coil axis 66 , goes along with it.

In contrast, the distance changes 63 between the string 20 and the coil 61 or magnet 62 in a transverse deflection purely perpendicular to the coil axis 66 only slightly. But exactly this is the direction actually struck parallel to the guitar body. The change caused by this deflection field change or in the string 20 induced stress is therefore much smaller than that caused by a string movement parallel to the coil axis 66 is produced.

The conventional pickup can thus neither the direction nor the orientation of a string movement parallel to the surface of the guitar body 1 determine. A conventional electromagnetic pickup 60 that's right under the string 20 is applied, thus does not generate its electrical signal from the movement of the string 20 in up and down direction, but only from the proportion of string vibration perpendicular to the fingerboard (not shown in 6a ) or perpendicular to the body of the stringed instrument 1 (See also H. Lemme, electric guitar sound, Richard Pflaum-Verlag, Munich, 1994, page 57).

A feasible, advantageous embodiment of the direction detection by means of a conventional pickup 60 is now the pickup 60 not directly under but according to 6b offset laterally and with respect to the normal installation direction by 90 degrees changed orientation under the string 20 to be mounted, in such a way that either magnet and coil axis are oriented parallel to the surface of the instrument and perpendicular to the strings or that the magnet is oriented perpendicular to the surface of the instrument and the strings and the coil parallel to the surface and perpendicular to the strings. Thus, the effects of the directions of the string vibrations with respect to the induced voltages in the coil with respect to the conventional arrangement ( 6a ) advantageous.

Under the stresses coming from the two transverse directions of movement in the coil 61 Now the one dominated by the deflection of the string 20 parallel to the surface of the guitar 1 , ie parallel to the changed coil axis 66 , is caused. In contrast, the distance between coil changes 61 and string 20 in the other transversal string movement perpendicular to the coil axis 66 and perpendicular to the surface of the guitar body 1 only slightly. The induced by this deflection field change or induced voltage in the coil is therefore much smaller than that which by a Saitenauslenkung parallel to the surface of the guitar 1 and coil axis 66 ie in the direction of impact or strike 43 respectively. 44 is produced.

The conventional pickup 60 can thus according to the arrangement 6b if he is sideways staggered under the string 20 is attached, both direction and orientation of a string movement parallel to the surface of the guitar body 1 determine.

In the third preferred embodiment, the direction of movement of the string by a special design of an electromagnetic pickup, as in 6c represented, determined. Again, the strings must be electrically conductive. Preferably, in this embodiment, the string is struck with a conventional plectrum.

This pickup can be like a conventional pickup 60 under the string 20 assemble. While a conventional electromagnetic pickup 60 only the transverse string movement in the direction 45 perpendicular to the surface of the guitar (not shown here), ie parallel to the coil axis 66 reliably converted into an electrical signal, the special design described here provides an electrical signal of the transverse movement directions P parallel to the guitar surface or perpendicular to the coil axis 66 ,

The special design is according to 6c from two left and right of the string 20 arranged coils 68 and 69 whose axes are perpendicular to the string and to the surface of the guitar body 1 and parallel to each other. Furthermore, a common magnet 62 provided, wherein the axis from the north to the south pole of the magnet is perpendicular to the surface of the stringed instrument. The coils are electrically connected in series, with the coil 68 to the coil 69 is wound in the opposite direction (or the polarity of the connections of coil 68 is opposite the coil 69 reversed).

Does the string move? 20 in the direction of impact 43 That's how the field of the magnet becomes 62 distorted in the way that the field lines, attached to the electrically conductive string 20 concentrate more, collect more on the impact side. On the impact side, the field strength thus decreases and on the knock-off side. In the coil 68 For example, a positive voltage is induced by the field enhancement. In coil 69 results in a weakening of the field strength. Would be coil 69 as wrapped as coil 68 , this would result in a negative induced voltage. But there the coil 69 wound in the opposite sense, results in a positive induced voltage, as well as in coil 68 , Does the string move? 20 in tee-off direction 44 , so in this example is in coil 68 and in coil 69 induced a negative voltage.

Kitchen sink 68 and coil 69 are connected in series, d. h the voltage add up. The sign of the electrical signal of this series circuit then contains the information as to whether the string is moving up or down.

The broken string 20 But not only swinging in the directions of movement of impact 43 or tee 44 but also in the direction of movement 45 perpendicular to the surface of the guitar 1 , This direction of motion induces in both coils 68 and 69 a signal that acts as a "jamming signal" to the signals in terms of directions 43 and 44 the two coils 68 and 69 must be treated. The interference signal is in terms of magnitude in both coils 68 and 69 exactly the same, but of opposite sign. Because the coils 68 and 69 are connected in series, cancel the two contributions of this disorder in the sum voltage of the series connection of these coils by itself.

If you extend the special design 6c on a guitar with 6 strings (not shown), so are two strings per string 68 and 69 needed. The coil diameter should only be half as large as the lateral distance of two adjacent strings 20 , It is enough to have a common magnet 62 under all 5 strings to lay.

The described embodiment of the special design of an electromagnetic pickup 6c , which converts the string movement parallel to the surface of the guitar into an electrical signal, is just one example among many other possibilities of combinations of one coil (or more coils) and one magnet (or more magnets) and different forms of arrangement of the coils and Magnets below or laterally offset below the strings and the transmitter for direction detection of the movement of the string.

According to a fourth embodiment of the device for detecting the direction of impact of the plectrum is the use of an ultrasonic device, which is directed to the hand of the musician or on the Plectron itself, according to 7 intended.

First, the ultrasonic device 70 Sensor consisting of transmitter 71 and receiver 72 eg mounted on a line perpendicular to all 6 strings 20 lies and about through the point of contact 46 of the plectrum 10 with the string 20 at the moment of the attack runs. In 7 is just a string for simplicity 20 drawn, the other guitar strings are parallel to this string.

The ultrasound transmitter 71 emitted ultrasonic waves are from the hand (not shown) or the plectrum 10 reflected and then back from the receiver 72 of the building ments 70 receive.

The direction of movement of the hand, which at the same time the direction of attack of the plectrum 10 and the string 20 at the time the string is hit, it is detected by measuring the Doppler effect:
If the hand or the plectrum moves 10 in tee-off direction 44 (in 7 the direction of the device 70 to), in this case has the received, by the hand or by the plectrum 10 reflected ultrasonic wave has a higher frequency than that of the ultrasonic transducer (transmitter) 71 emitted wave. Move hand or plectrum 10 in the direction of impact 43 , the effect reverses and the received reflected wave has a lower frequency than the transmitted wave.

Convert the emitted and received ultrasonic waves into DC voltages that are proportional to the received frequency and apply these two DC voltages to the inputs of a comparator or Schmitt trigger (not shown in FIG 7 ), so you get at the output of the comparator or Schmitt trigger digital information whether the hand and the pick for this attack move in impact or strike direction.

A Variant of this device to determine the direction of impact is, instead of ultrasonic waves, a measurement by means of microwave radar which also uses the Doppler effect. For this Must have the ultrasonic measuring device (Transmitter and receiver) corresponding microwave transmitters and receivers are replaced.

That one uses the Doppler effect very exactly and also very much can measure small distances (in the millimeter range) is from literature it can be seen which z. B. the measurement of the flow direction of the blood and describe its flow rate (ELV Journal "Fachmagazin for applied Electronics "edition 1/2001, page 16). Allow sensors with separate transmitting and receiving membrane to record measured values in the near range from approx. 20 mm (ELV Journal 1/2001, page 17).

Further could one extra Stroke direction detection integrate into the system by turning the pick of two electric forming conductive layers separated from each other by an insulator are separated when the layers have different electrical resistances, this leads to different voltage drops across the ladder cable / Plektron / string. These can additionally for the Control of effects are used.

In another executable Training will be the hand or Plectron movements through the use of retro-reflective sensors recognized, which are under the string and the hand or reflected light from the plectrum or string and thus the current string position and hereby the hand or Plectron movements measure up. Also can Photoelectric sensors are mounted parallel to the strings: for example be the transmitter on the saddle and the receiver on the bridge of the guitar attached to the current position of the plectrum and its movement to recognize.

Finally, in a further embodiment Strain gauges are glued to a flexible plectrum to make the stop timing and direction detection. there introduces Surcharge z. B. to an extension and an increase in resistance during a Tee z. B. for compression and thus resistance reduction of the strain gauge leads. Therefore, you can by the resistance change a premium of to distinguish a tee. Next can with strain gauges on the plectrum also the time of the attack itself can be detected. In this case, you can the strings and the plectrum also made of electrically non-conductive material become.

All the embodiments mentioned to the deadline time and Direction detection allows it, not just the timing of the attack to determine a string and its direction of movement, but it can also the number and individuality all simultaneously or sequentially struck strings and their Plays and forms of movement are determined to z. B. to provide a chord with a different effect than individually played sounds or sound sequences.

Associated digital Circuit for control tasks

The digital circuit for control tasks combines the attack timing detection, which is e.g. B. by means of an electrically conductive Plektrons, with the direction detection z. B. according to the electrodynamic (induction) principle 1 to 5 , the laterally offset arrangement of the conventional pickup under the string ( 6b ) or the special design of an electromagnetic pickup 6c or one of the other advantageous embodiments for direction detection described above.

For explanation shows 8th the contiguous digital circuit 80 , Here, for example, Ue, t (t) is the digital (attack) signal of the deep e string, by means of the beat timing detection 30 from the 2 and 3 processed becomes. UP0 (t) is the electrical (motion direction) signal from the impact direction detection 50 out 5 , which follows the induction principle at both ends of the e-guitar's low e-string 4 and 5 is tapped or recognized. UG (t) is the electric guitar signal of a conventional electromagnetic pickup.

If the low e-string struck with a mark, so z. B. the distortion effect 84 to be activated. At a tee, the chorus effect would 83 activated.

After each stop timing and direction detection in the switching elements 30 and 50 a takeover of the direction signal in the flip-flop takes place 81 with the output of a signal to the output Q. Finally, the switch controls 82 the choice of effect units 83 and 84 whose signals are fed to downstream amplifiers (not shown).

While the digital circuit in 8th only works with the stop timing and direction detection of a single string 9 the corresponding executable circuit for two strings. It consists of monoflops 30 and 31 for normalization and time delay after 3 and comparators 50 and 51 to 5 as well as logical switches 91 and 92 , a multiplexer 93 and a flip-flop 81 to 8th , For example, UP0 (t) is the electric direction signal of the low e-string and UP1 (t) is the electric direction signal of the a-string of the electric guitar. The switches 91 (logical AND) and 92 (logical OR) allow you to perform sound processing on strings that are played at the same time or one after the other. The multiplexer 93 controls the flip-flop 81 who like in 8th an effect device (not shown) is responsive, which causes the acoustic implementation of the selected guitar sound effect. In the 9 Registered table illustrates the function of the multiplexer 93 , It indicates which input (d0 or d1) of the multiplexer 93 depending on the level on the control line S from the multiplexer 93 is switched through.

If the e-string (not shown in 9 ) alone is struck, so is the exit 30 HIGH and the output 31 LOW. The AND gate 91 then supplies LOW on line S. Thus, as indicated in the table, the multiplexer switches the direction information d0 of the e-string to line Z. In addition, the OR gate 92 enables the flip-flop, this switches the line Z to the output Q and thus d0 to Q. The sound effect is then determined by the direction information d0 of the e-string.

If the a-strings (not shown in 9 ) alone is struck, so is the exit 31 HIGH and the output 30 LOW. At the entrance of the AND gate 91 this LOW is inverted to a HIGH. The AND gate 91 then supplies HIGH on the line S. Thus, as indicated in the table, the multiplexer switches the direction information d1 of the a string to the line Z. In addition, the OR gate 92 releases the flip-flop, this switches the line Z to the output Q and thus d1 to Q. The sound effect is then determined by the direction information of the a-string.

If both strings (not shown in 9 ) at the same time, these are the outputs 30 and 31 HIGH. The AND gate 91 then supplies LOW on line S. Thus, as indicated in the table, the multiplexer switches the direction information d0 of the e-string to line Z. In addition, the OR gate 92 releases the flip-flop, this switches the line Z to the output Q and thus d0 to Q. The sound effect is then determined by the direction information of the e-string. The e-string has priority.

For the extension on more than two strings can be the basic principle of this circuit to be kept. Only the O-DER function and the multiplexer need more inputs feature, and the control logic at the control inputs of the multiplexer becomes extensive.

10 shows the circuit for determining a control signal Q for controlling an effect device for four strings (e, a, d, g). The mode of operation and the name of the objects is quite analogous to 9 ,

Of course, it is always possible to have a separate, independent circuit for each string 8th to use. One possibility is to use pairs of strings with the circuit according to 9 summarize.

Next the stop detection by means of a conductive pickle, the described circuit with minor changes in combination used with other known methods for detecting attacks become.

in the Under the invention are different combinations of the stop time and the stop direction detection from the various described embodiments possible.

Claims (25)

Method for operating a stringed instrument ( 1 ), characterized in that for each string is determined individually, independently of the other strings, which of the strings ( 20 ) of the stringed instrument is struck or deleted at which time and whether the stroke or strike is an up or down stroke. A method according to claim 1, characterized in that for determining the stop time is determined when an electrical contact between the strings ( 20 ) and an at least partially electrically conductive plectrum ( 10 ) is closed. A method according to claim 1, characterized in that the stop time by means of strain gauges in Plektron ( 10 ) is detected. A method according to claim 1, characterized in that the stop time by means of piezo-pressure sensors in the bridge or the saddle of the stringed instrument ( 1 ) or in the plectrum ( 10 ) is detected. Method according to claim 1, characterized, that for striking the strings a plectrum is used, of which two Sides are electrically isolated from each other, each side of the Plectrons on contact the strings of the string instrument can each close a switch, whereby the attack time can be detected; and that is determined to determine the direction of attack, which the two switches closed. A method according to claim 1, characterized in that for determining the stop direction, the polarity of the deflected in the strings ( 20 ) is detected in a magnetic field induced voltage. A method according to claim 1, characterized in that for determining the stop direction of a string a pickup ( 60 ) with at least one coil ( 61 ) and at least one magnet ( 62 ) is used, that the at least one coil ( 61 ) and the at least one magnet ( 62 ) of the pickup laterally offset below the string ( 20 ), and that the at least one coil ( 61 ) and the at least one magnet ( 62 ) are arranged and oriented so as to control the movement of a string ( 20 ) of the stringed instrument ( 1 ) parallel to the surface of the stringed instrument ( 1 ) into an electrical signal. A method according to claim 1, characterized in that for determining the stop direction, a pickup ( 60 ) with two oppositely wound coils ( 68 . 69 ), or that a pickup ( 60 ) with two coils wound in the same direction ( 58 . 69 ), in which the polarity of the connections is reversed, that the coils ( 68 . 69 ) are connected in series, and that the polarity of the in the coils ( 68 . 69 ) induced voltage is detected. Method according to Claim 1, characterized in that the stop direction is determined by an ultrasonic Doppler effect measurement on a plectrum (FIG. 10 ) or on a hand striking the strings. Method according to claim 1, characterized in that the stop direction is medium from the plectrum ( 10 ) or hand-reflected microwave intensity is measured with the Doppler effect. A method according to claim 1, characterized in that the stop direction by means of recording the movement of the plectrum ( 10 ) or the hand is measured by means of at least one video camera. A method according to claim 1, characterized in that the stop direction by means of recording the movement of the hand or the plectrum ( 10 ) or the strings ( 20 ) is measured by means of light barriers. A method according to claim 1, characterized in that the stop direction by means of strain gauges in Plektron ( 10 ) is measured. A method according to claim 1, characterized in that the stop direction by means of piezo-pressure sensors in the bridge or the saddle of the stringed instrument ( 1 ) or in the plectrum ( 10 ) is determined. Method according to one of the preceding claims, characterized characterized in that the detected stop direction for control a synthesizer is used. Device for measuring the timing and direction of a string stop, with an electrically conductive string ( 20 ) of a stringed instrument ( 1 ), with an electrically conductive pick ( 10 ) for striking the electrically conductive string ( 20 ), the plectrum ( 10 ) has an electrically conductive front side and an electrically conductive rear side, which are separated from each other by an electrical insulation, and with means for detecting an electrical contact between the electrically conductive string ( 20 ) and the eltrtrisch conducting plectrum ( 10 ). Device for operating a stringed instrument ( 1 ) with a pickup ( 60 ) with at least one coil ( 61 ) per string and at least one magnet ( 62 ) per string, whereby the at least one coil ( 61 ) and the at least one magnet ( 62 ) are arranged such that they control the movement of a string ( 20 ) of the stringed instrument ( 1 ) parallel to the surface of the stringed instrument ( 1 ) into an electrical signal, characterized in that the pickup ( 60 ) placed laterally under the string ( 20 ) on the body of the stringed instrument ( 1 ) and that the direction of the axes ( 66 ) of the at least one coil ( 61 ) and the at least one magnet ( 62 ) are oriented so that either the coil axis ( 66 ) and the axis from the north to the south pole of the magnet ( 62 ) parallel to the surface of the stringed instrument ( 1 ) and perpendicular to the string ( 20 ) or that the axis from the north to the south pole of the magnet ( 62 ) perpendicular to the surface of the stringed instrument ( 1 ) and the direction of the string ( 20 ) and the coil axis ( 61 ) parallel to the surface of the stringed instrument ( 1 ) and perpendicular to the string ( 20 ) or that the pickup ( 60 ) under the string ( 20 ) on the body of the stringed instrument ( 1 ) is positioned that a magnet ( 62 ), wherein the axis from the north to the south pole of the magnet is oriented perpendicular to the surface of the stringed instrument that two left and right of the string ( 20 ) arranged coils ( 68 . 69 ) are provided whose axes are perpendicular to the string ( 20 ) and the surface of the stringed instrument ( 1 ) and are oriented parallel to each other, that the coils are electrically connected in series, that the coil ( 68 ) to the coil ( 69 ) is wound in the opposite direction or the polarity of the terminals of the two coils ( 68 . 69 ) is reversed. String instrument ( 1 ) with at least one string ( 20 ), characterized by means for measuring (a) the stop time and (b) the stop direction for each string ( 70 ) individually, independently of the other strings. String instrument according to claim 18, characterized in that the means for measuring the moment of impact is a device according to claim 16. String instrument according to claim 19, characterized in that the strings ( 20 ) are electrically conductive and electrically isolated from each other, and that the web of the stringed instrument ( 1 ) is made of electrically insulating material. String instrument according to one of claims 18 to 20, characterized in that the means for measuring the stop direction an apparatus according to claim 17. String instrument according to one of claims 18 to 20, characterized in that the means for measuring the direction of attack an ultrasonic or microwave device ( 70 ) with transmitter ( 71 ) and receiver ( 72 ) for Doppler velocity measurement is that the device ( 70 ) on the string instrument ( 1 ) is positioned so that the transmitter ( 71 ) in the direction of the plectrum ( 10 ) or the hand shows and the plectrum ( 10 ) or hand-reflected ultrasonic or microwave intensity to the receiver ( 72 ) of the component ( 70 ) meets. String instrument according to one of claims 18 to 20, characterized in that the means for measuring the direction of attack is a video camera which is placed on the plectrum ( 10 ) or the hand is directed. String instrument according to one of claims 18 to 20, characterized in that the means for measuring the stop direction is at least one piezo-pressure sensor which is in the bridge, in the web o of the saddle of the string instrument ( 1 ) or in the plectrum ( 10 ) is arranged. Arrangement with the stringed instruments ( 1 ) according to one of claims 18 to 24 and with a synthesizer which is controllable by the detected stop direction.