EP1859434B1 - Device for automatically tuning a string of a stringed instrument - Google Patents

Abstract

A device is disclosed for tuning at least one string of a string instrument, preferably a guitar, in particular an electric guitar or a bass, in particular an electric bass, comprising a detection device for detecting a note generated by striking a string and for output of a signal corresponding to the note detected, a memory device for storing preselected signals, corresponding to a desired note, a comparator device for comparing the signal output by the detection device with a signal corresponding to the desired note and stored in the memory device, an adjusting device for varying the tension of at least one of the strings, at least one drive for driving the adjusting device, a controller connected to the comparator device and controlling the at least one drive via a control line on the basis of a deviation found in the comparator device between the signals representing the note thereby generated and signals representing the desired note. To design such a device so that it can be integrated into an instrument, in particular a guitar or a bass with a minimal influence on the sound properties and with the smallest possible number of elements that are also as small as possible and nevertheless allow variable design options, it is proposed that the detection device should be a piezoelectric pickup arranged directly on the adjusting device.

Description

The present invention relates to a device for automatically tuning a guitar, in particular electric guitar, or a bass, preferably an electric bass, according to the preamble of claim 1.

The tuning of these instruments requires in addition to a trained hearing a lot of time, which must be applied in particular by untrained, for example, hobby instrumentalists. In the classical method of tuning "by hand" the musician works with a tuning fork, which sets the desired tone by striking and adjusts the pitch of the respective string by changing the string length or string tension. By repeatedly striking the string and the tuning fork, the result is adjusted until the desired tuning of the string is achieved. Based on this mood then the other strings are tuned.

On the one hand the strings of the instruments have to be regularly tuned because of a constantly existing flexibility of the material, the strings are partly variable also depending on the climatic conditions in their length (a guitar string, for example, expands on the stage of a concert hall with the heat and damp air in the Compared to the conditions in the comparatively dry and cool practice room, a frequent tuning is required. Even after putting on new strings they have to be tuned.

To create a relief, was in the US 4,803,908 proposed a device for automatically tuning a guitar. In this device, all strings are struck simultaneously on the guitar with a "Strummer" mentioned there, arranged in the body of the guitar tools. An electronics detects the sounds, comparing them with the target specification and controls an acting on the strings adjusting device for adjusting the string tensions in such a way that they hit the predetermined tones on.

The system is to be welcomed in so far as it allows a speedy and automatic tuning and so in particular untrained musicians, but also the professionals a great deal of effort decreases. However, the system has a not insignificant disadvantage. It is large and chunky overall and requires considerable changes to the body of the guitar, which on the one hand have an influence on their acoustics (sound) and on the other hand on their handling (because of the changed weight). Apart from that, the look of the guitar is changed in a significant way.

Since the entire guitar forms the resonant body relevant for the sound properties, the sound also changes Sound properties when it is changed. Thus, the previously known system in existing instruments is almost impossible to retrofit, but it can also be difficult to integrate into new guitars. In particular, in terms of sound, two types of guitar would have to be developed independently of each other, a guitar with the previously known device and one without.

In the US 5,390,579 is a device for automatically tuning the strings of a guitar, are arranged in the region of the bridge to the body of the guitar piezo pickup for determining the frequency of the vibrating strings. These are evaluated when tuning to control arranged in the bridge actuators while adjusting the string tension to tune the strings. Here, too, the specialized for voices bridge is a special component that can not be easily retrofitted into a standard guitar.

In the WO 03/012774 A1 is described a system for tuning a guitar, in which the actual mood is tapped by arranged on the guitar body in the region of the bridge sensors of unspecified nature and fed to a likewise arranged on the body control. The controller then communicates with an actuator located at the head of the guitar, which itself has no sensors and changes the string tension according to the instructions of the controller. This solution always requires communication between the controller on the body of the guitar and the adjusting elements on the head, are provided for the corresponding lines or a vulnerable radio link can be established.

From the described problem, the invention proceeds. It has the task, as far as improved device which can be integrated into a guitar or a bass, with minimal influence on the sound characteristics and with as few and small elements as possible. In particular, the device should be constructed in a modular manner and be variably designed accordingly.

To solve this problem, a device for automatically tuning a guitar or a bass having the features of claim 1 is proposed. Advantageous developments of the device are specified in the dependent claims 2 to 4. A further embodiment of the invention lies in a guitar or a bass according to claim 5 with special developments according to claims 6 to 9.

The design method according to the invention is initially made possible by the fact that a piezo pickup is used as detection device or sensor element for detecting the sound generated by a broken string, which is arranged directly on the adjusting device. Piezo-pickups are structure-borne sound sensors that perceive the sound transmitted in solids and convert it into an electrical signal. Such piezoelectric pickups can be manufactured as particularly small elements. The advantage that piezoelectric pickups are used, which are arranged directly on the adjusting device, is that they can be arranged in a space-saving and "unobtrusive" manner on the stringed instrument.

Although it is known, for example, aufklemmen on the neck of a guitar an arrangement with piezo pickups, but this arrangement is visually distracting and relatively inaccurate, since the piezoelectric pickups are not directly connected to a body directly connected to the vibrating string, but the sound waves on one Perceive the air gap between the string and the piezo pickup. For a highly precise and accurate determination of the sound generated by the broken string, a piezo pickup attached in this way is not accurate enough.

This is different in the inventively provided arrangement of the piezoelectric pickup directly to the adjusting device. Typically, the string runs directly on the actuator and is in direct physical contact with it. Here, therefore, the sound of the vibrating string is transmitted directly and precisely to the body of the adjusting device and can be accurately detected by the piezoelectric pickup arranged directly thereon.

Furthermore, the invention provides that the adjusting device are each provided with a vortex and a wing for adjusting the vortex mechanisms and that the piezoelectric pickup is arranged directly on at least one of the mechanisms. These tuners are located at the head of the guitar or the bass, which usually offers little space for the arrangement of other elements.

Here now the advantage comes into play, that an arrangement of the piezo pickup directly to the adjusting device of the string instrument offers the opportunity to construct the inventive device for automatic tuning of the guitar or the bass modular. Thus, some or all of the other elements of the device may be arranged on the body of the instrument, in which case it must be ensured that control signals such as power supply starting from the body to the head of the instrument can be performed to control the at least one actuator. This can be done, for example, by utilizing the strings as current-carrying elements.

The piezo pick-up can be embedded in the mechanism, e.g. screwed or pressed, be (see claim 3) or glued to these (see claim 2).

In addition to serving as a detection device for the device for automatic tuning of the stringed instrument, the piezoelectric pickup can additionally fulfill other functions. In claim 4, a preferred embodiment is provided, according to which the tapped signals from the piezo pickups can also be used as control signals, for example. As MIDI signals. It is also conceivable to use the signals of the piezo pickups for acoustic reproduction of the sound of the stringed instrument, for which purpose they are fed to an amplifier. For example, in the case of an electric guitar or an electric bass, it is possible to produce a sound of the instrument that is altered compared to a decrease with the electromagnetic so-called "pick-ups". If the piezo pickups are to be additionally used in a manner described above, only signal lines must be provided with which the signals detected by the piezo pickups are fed to a corresponding electrical output of the instrument.

According to the advantageous development described in claim 6, the drive for driving the adjusting devices in the form of the mechanisms can be formed by one or more motor (s) in a device provided with the guitar or bass. One or two motors can drive several of the vertebrae via a switchable gearbox and intermediate flexible shafts, or a separate motor can be present per vortex.

In claim 7, an advantageous development is specified, according to which the control with the comparison device are likewise arranged on the head of the guitar or of the bass. Similarly, an energy source for supplying at least a portion of the components of the device with energy at the head of the guitar or the bass may be arranged (claim 8).

Preferably, a mechanism is arranged on each string of the guitar or the bass and a piezo pickup is attached directly to each of the mechanisms (claim 9).

In principle, it is also conceivable to use the inventively provided, arranged directly on a mechanics piezoelectric pickup in a device that is not intended for automatic tuning of a guitar, but only as a voice aid. Such a device would lack the drive to adjust the mechanism, instead the control would be connected to a display representing a deviation from the target tone, for example by an LED display or a pointer display. Such a display may also be present in a device for automatic tuning of the instrument as described and claimed.

Further advantages and features of the invention will become apparent from the following description of an embodiment with reference to the accompanying figures. In the embodiment, the present invention will be explained with reference to an implementation in an electric guitar. However, the invention is not limited to this instrument, but can be used in all guitars and basses are used.

Fig. 1

eine schematische Ansicht einer E-Gitarre,

Fig. 2

in dreidimensionaler Ansicht schematisch eine einzelne Mechanik der E-Gitarre mit aufgeklebtem Piezoabnehmer und Anschluss für eine Antriebswelle eines Antriebsmotors,

Fig. 3a

eine alternative Ausgestaltung einer mit einem

und 3 b

Piezoabnehmer versehenen Mechanik, bei der der Piezoabnehmer in die Mechanik eingelassen, bei diesem Ausführungsbeispiel in konischer Form eingepresst, ist,

Fig. 4

eine mögliche Anordnung eines aus zwei Motoren und einem Getriebe gebildeten Antriebes für die Wirbel am Kopf der E-Gitarre und

Fig. 5

eine Schnittdarstellung genommen entlang der Schnittlini IV - IV aus Fig. 4.

In the figures show:

Fig. 1

a schematic view of an electric guitar,

Fig. 2

in three-dimensional view schematically a single mechanics of the electric guitar with glued piezo and connection for a drive shaft of a drive motor,

Fig. 3a

an alternative embodiment of a with a

and 3 b

Piezo-receiving mechanism provided in which the piezoelectric pickup inserted into the mechanism, in this embodiment, in a conical shape, is pressed,

Fig. 4

a possible arrangement of a drive formed by two motors and a gearbox for the vortex at the head of the electric guitar and

Fig. 5

a sectional view taken along the Schnittlini IV - IV Fig. 4 ,

In the figures, the same or similar elements are provided with the same reference numerals.

In Fig. 1 is shown schematically as an example of a stringed instrument (guitar or bass), in which the device according to the invention can be realized, an electric guitar 1 shown. This can be roughly divided into a body 2, in a neck 3 and a head 4. On the body 2 is a mounting block 5, in this case, a tremolo system block on which the six strings 6a to 6f of the guitar 1 with a first end are fixed. The strings 6a to 6f extend from there along the body 2, the neck 3 to the head 4, where they on vertebrae 7 arranged on the head 4 mechanisms 10 as adjusting devices for adjusting the string tension (see. FIGS. 2 . 3a . 3b . 4 and 5 ). To adjust the vortex 7 10 wings 8 are arranged on the mechanisms. Below the strings 6a to 6f is located on the body 2 of the electric guitar 1, a so-called "pick guard". 9

In the FIGS. 2 . 3a and 3b is shown how according to the invention on these mechanisms 10, piezoelectric pickup 16 are arranged directly. The FIGS. 2 3a and 3b show two different variants of the possible direct attachment of the piezo pickup 16 to the mechanisms 10. In the in Fig. 2 illustrated example, the piezoelectric pickup 16 is glued on an element of the mechanism 10. In the in the FIGS. 3a and 3b As shown, the piezoelectric pickup 16 is embedded in a part of the mechanism 10, pressed in here. This is especially good in the sectional view of Fig. 3b to recognize. In the latter example, the piezoelectric receiver 16 is conically shaped and pressed into a correspondingly complementarily shaped receptacle in the mechanism 10. At 17, a signal line of the piezoelectric pickup 16 is indicated in each case, which forwards the sound signals detected by the piezoelectric pickup 16 to the comparison device or the controller.

In Fig. 2 Furthermore, a connection 18 for connecting a drive, in this example a motor 15 connected or connectable shaft is shown. Such a connection is in principle also with the in.den FIGS. 3a and 3b shown embodiment, but not shown there in detail.

In the FIGS. 4 and 5 For example, one possible arrangement of drive motors 15 for driving the mechanisms 10 is shown. Here are two drive motors 15 mirror-inverted arranged opposite each other. The drive motors 15 run in the same direction and transmit their driving force directly to a respective motor 15 associated drive roller 14. In the field of drive rollers 14 take-off wheels 13 are provided which can be selectively brought into engagement with one of the drive rollers 14. For this purpose, the surfaces of the drive rollers 14 and the take-off wheels 13 are preferably made of a rubber to achieve the highest possible friction and thus a transmission of the respective torque. A total of six pick-up wheels 13 are arranged, of which in Fig. 4 only three are visible. The other three are in Fig. 4 Each of the take-off wheels 13 is connected to a flexible shaft 11, which is guided to the terminal 18 in the associated mechanism 10 below the plane.

• Zunächst wird die Gitarre in einen Stimmmodus geschaltet, bspw. durch Betätigen eines entsprechenden Schalters. Dann wird wenigstens eine der zu stimmenden Saiten angeschlagen. Der dabei entstehende Schall bzw. der dabei entstehende Ton wird über das auf den jeweiligen Wirbel 7 der zugeordneten Mechanik 10 auflaufende Ende der Saite auf die Mechanik 10 übertragen. Dort erfasst der unmittelbar auf der Mechanik 10 angeordnete Piezoabnehmer 16 das Schallsignal und gibt es über die Signalleitung 17 an eine nicht dargestellte Vergleichseinrichtung weiter. Die Vergleichseinrichtung ist vorzugsweise ebenfalls am Kopf 4 der E-Gitarre 1 angeordnet. In der Vergleichseinrichtung wird der tatsächlich erfasste Ton, bspw. anhand einer Frequenz, mit einem in einer hier ebenfalls nicht dargestellten, vorzugsweise ebenfalls am Kopf 4 der Gitarre 1 angeordneten Speichereinrichtung abgelegten Soll-Wert verglichen. Die Abweichung wird an eine hier ebenfalls nicht dargestellte Steuerung, die auch vorzugsweise am Kopf 4 der E-Gitarre 1 angeordnet ist, weitergegeben. Anhand der Abweichung bestimmt die Steuerung eine Richtung, in der die Saite zu bewegen ist (Spannen bzw. Entspannen). Dann gibt die Steuerung ein entsprechendes Signal an die in Fign. 4 und 5 dargestellte Einheit aus Motoren 15 und durch die Abnahmeräder 13 und Antriebswalzen 14 gebildetem Getriebe weiter, wodurch das der Mechanik 10, auf der die zu stimmende Saite aufläuft, zugeordnete Abnahmerad 13 je nach Stellrichtung der Saite an eine der Antriebswalzen 14 gepresst und der zugehörige Motor 15 eingeschaltet wird. Über die mit dem entsprechenden Abnahmerad 13 verbundene flexible Welle 11 wird das Drehmoment auf die Mechanik 10, dort schließlich auf den Wirbel 7 übertragen, so dass die Saitenspannung verändert wird. Dadurch verändert sich der von der Saite abgegebene Ton in seiner Frequenz, was wiederum von dem Piezoabnehmer 16 erfasst und an die Vergleichseinrichtung gemeldet wird. Erst wenn die Vergleichseinrichtung eine Übereinstimmung zwischen dem erfassten Wert und dem Soll-Wert feststellt, steuert die Steuerung die Motoren 15 und das aus den Abnahmerädern 13 und Antriebswalzen 14 bestehende Getriebe an, um eine weitere Veränderung der Saitenspannung zu unterbinden.

The inventive device for automatic tuning of the electric guitar 1 shown here works as follows:

• First, the guitar is switched to a voice mode, for example, by pressing a corresponding switch. Then at least one of the strings to be tuned is struck. The resulting sound or the resulting sound is transmitted to the mechanics 10 via the end of the string coming to the respective vertebra 7 of the associated mechanism 10. There, the piezo pickup 16 arranged directly on the mechanism 10 detects the sound signal and transmits it via the signal line 17 to a comparison device, not shown. The comparison device is preferably also arranged on the head 4 of the electric guitar 1. In the comparison device, the actually detected tone, for example, based on a frequency, with a in a here not shown, preferably also arranged on the head 4 of the guitar 1 arranged storage device stored target value compared. The deviation is passed on to a control, likewise not shown here, which is also preferably arranged on the head 4 of the electric guitar 1. Based on the deviation, the controller determines a direction in which to move the string (tensioning or relaxing). Then the controller gives a corresponding signal to the in FIGS. 4 and 5 shown unit of motors 15 and by the take-off wheels 13 and drive rollers 14 formed gear on, whereby the mechanism 10, on which the tuned string runs, associated Abnahmerad 13 depending on the direction of the string to one of the drive rollers 14 pressed and the associated motor 15th is turned on. Via the flexible shaft 11 connected to the corresponding take-off wheel 13, the torque is transmitted to the mechanism 10, there finally to the swivel 7, so that the string tension is changed. As a result, the tone emitted by the string changes in its frequency, which in turn is detected by the piezo pickup 16 and reported to the comparison device. Only when the comparator detects a match between the detected value and the target value does the controller control the motors 15 and the transmission consisting of the take-off wheels 13 and drive rollers 14 to prevent further variation of the string tension.

LIST OF REFERENCE NUMBERS

1

electric guitar

2

corpus

3

neck

4

head

5

Tremolo system block

6a-f

string

7

whirl

8th

wing

9

Pick Guard

10

mechanics

11

flexible shaft

12

transmission

13

take-off

14

drive roller

15

engine

16

Piezo-Pickups

17

signal line

18

connection

Claims (9)

1. A device for tuning at least of one string(6a - 6f) of a guitar (1), in particular of an electric guitar, or a bass, in particular of an electric bass, with:

   a) a detection device for detecting a sound generated by striking the string (6a - 6f) as well as for outputting a signal corresponding to the detected sound,

   b) a storage device for storing preset signals, which correspond to a requested sound, a comparison device for comparing the signal produced by the detection device with one signal stored in the storage device, corresponding to the requested sound,

   c) an adjustment device (10) for changing the tension of at least one of the strings (6a - 6f),

   d) at least one drive unit (15) for driving the adjustment device (10),

   e) a control unit connected to the comparison device, which, on the basis of a deviation observed in the comparison device between signals representing the produced sound and the requested sound, operates said at least one drive unit via a control line,
   whereas the detection device is a piezo receiver (16) arranged directly on the adjustment device, characterised in that the adjustment device (10) is a mechanism provided for arrangement on a head (4) of the guitar (1) or of the bass with a swivel (7) and a wing (8) for adjusting the position of the swivel (7) and that the piezo receiver (16) is arranged directly on the mechanism.
2. A device according to claim 1, characterised in that the piezo receiver (16) is glued on a portion of the mechanism.
3. A device according to claim 1, characterised in that the piezo receiver (16) is nested into a portion of the mechanism, for example screwed in or pressed in.
4. A device according to one of the preceding claims, characterised in that an output of the piezo receiver (16) is connected in such a way that signals collected therefrom may also be used as control signals, for example as MIDI signals.
5. A guitar or bass with a device according to one of the preceding claims.
6. A guitar or bass according to claim 5, characterised in that that the drive unit (15) consists of at least one motor arranged on the head (4) of the guitar (1) or of the bass, which is connected therewith for driving the mechanism (10) .
7. A guitar or bass according to one of the claims 5 or 6, characterised in that the control unit with the comparison device is arranged on the head (4) of the guitar or of the bass.
8. A guitar or bass according to one of the claims 5 to 7, characterised in that an energy source provided for supplying at least one portion of the components of the device is arranged on the head (4) of the guitar (1) or of the bass.
9. A guitar or bass according to one of the claims 5 to 8, characterised in that a mechanism (10) is allocated to each string (6a - 6f) of the guitar (1) or of the bass and that a piezo receiver (16) is arranged directly on each of the mechanisms (10).

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