EP1596359B1 - Device and method for automatically tuning a stringed instrument in particular a guitar - Google Patents

Abstract

A controller (10) and at least one drive for changing the string tension are arranged in the stringed instrument (1) on opposing sides of the strings when viewed in the longitudinal direction of the strings. A bus line is provided between the controller and the drive, so as to span the length of the strings. An independent claim is included for a method of automatically tuning a stringed instrument.

Description

The present invention relates to a device for automatically tuning a stringed instrument according to the preamble of claim 1. It further relates to a method for automatically tuning a stringed instrument according to the preamble of claim 9.

The tuning of instruments in addition to an experienced hearing generally requires 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 regularly tuned because of the constant resilience of the material Otherwise, the strings are also variable in length depending on the climatic conditions (a guitar string stretches on the stage of a concert room with the heat and humid air compared to the proportions in the comparatively dry and cool practice room) is a frequent one Voices required. Even after putting on new strings they have to be tuned.

To create a relief, was in the US 4,803,908 a device for automatically tuning a stringed instrument proposed, which has all the features of the preamble of claim 1. In this device, all strings are struck simultaneously on a 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 attacking on the strings adjusting device for adjusting the string tensions in such a way that they hit the preset tones on.

The system is to be welcomed so much that 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, 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 to the sound characteristics, the sound characteristics change as well, if this is changed. This is the previously known system in existing instruments 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 WO 03/012774 A1 An electronic device for automatically tuning a guitar is disclosed, which shows a distribution of components on the head and the body of the guitar. In this device, either a wiring of the separate components is provided for data transmission, which requires a massive engagement in the guitar, with all the consequences described above for the guitar sound. Or it is a wireless, infrared or other wireless transmission provided. For this purpose, however, an appropriate transmitter / receiver must be additionally attached to the head, which brings further weight and can interfere with the appearance as well as the sonic behavior of the guitar. Furthermore, this transmitter / receiver must be provided with an independent power supply, ie at the head of the guitar is in addition to provide a battery or even a feeder cable connection.

From the described problem, the invention proceeds. It has for its object to provide an improved device so far, which can be integrated into an instrument, in particular a guitar, with minimal influence on the sound properties and with as few and small elements. Furthermore, a method for automatic tuning of a stringed instrument is to be specified, which meets these requirements.

To solve this problem, a device with the features of the protection claim 1 is proposed. A procedure, which solves this problem is specified in claim 9.

The claims 2 to 8 and 10 to 11 contain advantageous developments of the device or the method.

The core idea of the invention is to distribute the components of the device (which can also be referred to as a system) on the instrument. In a guitar, for example, not the entire device is placed in the body. Thus, the head or neck also offers, albeit only little, space for the (subtle) attachment of other components. In particular, means for adjusting the string length or tension arranged on guitars anyway can be used, which reduces the use of special parts. Overall, less additional components must be introduced into the instrument, for example the guitar.

In order to make the separation of the components control and drive without profound interference with the instrument body, according to the invention, the control signals between the seated on an instrument part control and the at least one drive via at least one serving as bus lines string of the guitar.

The strings of stringed instruments are in many cases made of a conductive material (metal) or are wrapped by a thread of such. Alternatively, if the sound permits, they may be coated with a conductive material. This solution saves the use of additional lines that would need to be laid in the instrument body. In addition to the sound properties, the optics of the instrument are preserved. Thus, if several strings are to be used as a conductor, these not among themselves are electrically short-circuited, elements over which the strings are performed together (eg. The bridge on a guitar) must be designed so that they isolate the strings against each other. These elements may be made of a non-conductive material (eg. Ceramic) or coated with such, or it must be made other arrangements of the insulation (eg. Between ordered insulating, etc.).

The drive can be a motor, for example. Electric motor, but he can also work pneumatically or hydraulically.

If the instrument is an electrically connected instrument to an amplifier (eg an electric guitar), an already existing and connected to the amplifier pickup of the instrument can be used as (part of) the detection unit.

If, as in a development according to claim 2, the power supply for the at least one drive is guided over at least one of the strings, no separate power supply (battery or similar) must be provided on the side of the drive, resulting in an additional component with all negative consequences for the optics and the balance of the instrument would lead, and it must be laid no separate supply line, which would lead to the disadvantages already mentioned above.

By specified as in claim 3 embodiment of the controller, this can be addressed in a simple manner by striking a page.

An interface, as it can be provided according to claim 4, gives the possibility of externally - and subsequently - to feed software into the device. Furthermore, different reference tunings can be transmitted via the interface the memory device can be input in order to be able to tune the instrument according to different schemes.

An as proposed in claim 5 embodiment of the device allows a stringwise tuning of the instrument. It can just as well a drive can be used, which can be switched by appropriate gear or similar devices for adjusting one string.

If the device is formed as specified in claim 6, results in a particularly compact design. If the individual components are chosen as small as possible, they "disappear" almost in the overall impression of the instrument and do not disturb the musician when playing the same. In addition, it is not necessary to use external components when tuning the instrument, the musician can tune his instrument virtually anywhere and almost independently.

A development of the device according to claim 7 results in a redundant system. The device can be operated even in case of defect of a string even further to the tuning of the instrument.

In claim 8, a preferred embodiment of the device for integration in an electric guitar is specified.

The method according to claim 9, as already stated above, represents a solution of the above-mentioned object with regard to a method. It can preferably be operated with a device according to one of claims 1 to 8, but is not limited to such a device, according to the According to the invention methods the strings of the instrument can be used as bus lines. As a result, no separate cables or other means of transmission (radio, infrared) must be installed.

A processing of the first digital signal as required in a development of the method according to claim 10 may be useful in order to be able to reliably determine a pitch from this signal.

A determination of the fundamental frequency (pitch) of the first digital signal is preferably carried out with the aid of a mathematical frequency filter (claim 11). This allows, in contrast to the otherwise common Fast Fourier Transformation (FFT) method, a faster and more accurate frequency determination from only one stop of the string. This is important because with only one stop of the string, the overtones that must be detected for an exact determination of the pitch (frequency), decay very quickly.

Fig. 1

eine schematische Ansicht von vorn einer E-Gitarre als mögliches Anwendungsbeispiel der Erfindung,

Fig. 2

eine schematische Ansicht der E-Gitarre aus Fig. 1 von hinten,

Fig. 3

eine weitere schematische Ansicht der E-Gitarre mit anderen Einzelheiten,

Fig. 4

eine vergrößerte Darstellung des Korpus der E-Gitarre nach der Darstellung in Fig. 3,

Fig. 5

in vier verschiedenen Darstellungen (a) bis (d) einen Reiter des Tremolosystem-Blocks der E-Gitarre,

Fig. 6

schematisch die Befestigung der Saiten im Tremolo-Systemblock sowie deren Kontaktierung mit den Spannungsversorgungs- bzw. Signalleitungen,

Fig. 7

in vier verschiedenen Ansichten (a) bis (d) den Kopf der Gitarre mit daran angebrachten Flügeln und Stellmotoren zum Einstellen der Saitenspannung,

Fig. 8

in vier verschiedenen Ansichten die in dem Kopf der Gitarre sitzenden Flügelt mit den Stellmotoren und

Fig. 9

eine schematische Schaltskizze einer Detektorschaltung zur Ansteuerung einer Tonaderspeisung für die Vorrichtung zum automatischen Stimmen der Gitarre.

In the following, the invention will be briefly described with reference to the accompanying figures. Show it:

Fig. 1

a schematic front view of an electric guitar as a possible application example of the invention,

Fig. 2

a schematic view of the electric guitar Fig. 1 from behind,

Fig. 3

another schematic view of the electric guitar with other details,

Fig. 4

an enlarged view of the body of the electric guitar as shown in Fig. 3 .

Fig. 5

in four different representations (a) to (d) a rider of the tremolo system block of the electric guitar,

Fig. 6

schematically the attachment of the strings in the tremolo system block and their contacting with the voltage supply or signal lines,

Fig. 7

in four different views (a) to (d) the head of the guitar with attached wings and actuators to adjust the string tension,

Fig. 8

in four different views sitting in the head of the guitar wings with the servomotors and

Fig. 9

a schematic circuit diagram of a detector circuit for controlling a Tonaderspeisung for the device for automatic tuning of the guitar.

In the figures, the invention is explained in more detail using an exemplary embodiment in an electric guitar. Identical elements are provided in the figures with the same reference numerals. The description based on an electric guitar does not limit the invention. It can also be used with acoustic guitars, electric basses, or other electric or electro-acoustic or acoustic string instruments such as violins, harps, etc.

In the FIGS. 1 to 4 is shown in various, partially enlarged views of an electric guitar 1, which is provided with a device according to the invention. The electric guitar 1 can be roughly divided into the body 2, the bridge 3 and the head 4. On the body of the so-called tremolo system block 5, the strings 6a - 6f with their first ends (ball ends) attached and side by side on the Bridge 3 stretched to the head 4, where they are wound with their second ends on vertebrae 7 and set adjustable. The vortices 7 are mechanically connected with wings 8, so that by turning the wing 8, the string end up on the vertebra 7 or can be unwound from this. This changes the tension or length of the string and tunes the guitar.

In FIG. 1 In addition, a so-called pick-guard 9 can be seen, which is a kind of cover plate and under which a space is created in the body 2, in which the electronics of the electric guitar 1 is arranged. Below this pick guards 9 a belonging to the inventive device control chip is arranged in Fig. 2 is indicated schematically with 10.

In Fig. 2 It can also be seen that on the head 4 of the electric guitar 1 on the mechanics of the wings 8, for example. Via a gear, attacking servomotors 11 are arranged. The Actuators belong to the device according to the invention and are connected in a manner to be described later with the control chip 10 for driving. With the motors, as an alternative to the manual over the wings 8, the vortex 7 is rotated and thus the tension of the strings 6a to 6f are adjusted.

In the FIGS. 3 and 4 is shown in another illustration, the electric guitar 1. Here are next to the in FIGS. 1 and 2 to be recognized elements further details of the electric guitar 1 shown. Thus, for example, the pickups (pickups) 12 seated on the body 2 below the strings 6a to 6f can be seen, which convert the vibrations of the strings (and thus the sound produced by striking them) into an electrical signal. These pickups 12 are also used later in a manner to be explained as part of the device according to the invention.

Furthermore, in these representations, a potentiometer 13 is shown. Typically, electric guitars have several such potentiometers for adjusting treble, bass, and volume. Here is the illustrated potentiometer 13 of the volume control. This special controller is designed to integrate the device according to the invention in the electric guitar 1 not as a conventional potentiometer, but as a so-called push-pull potentiometer, which has an additional switching function.

Finally, the lines 14 leading from the control chip to the tremolo system block 5, more precisely to the strings 6a to 6f, can still be seen in these figures.

In the FIGS. 5 and 6 is the tremolo system block 5 and are arranged on this rider 15 for guiding the specified in the tremolo system block 5 string ends. In Fig. 6 It can be seen how the strings 6a to 6f guided by holes 17 in the tremolo system block 15 and held at their ends thickening (ball ends) 18 at the lower edge of the holes 17. In the lower end of the holes 17, an insulating sleeve 19 is used in each case, which is provided at its protruding from the bore 17 edge with an outwardly facing collar. Between the collars of the sleeves 19 and the ball ends 18 are positioned conductive discs 20 which contact the ball ends 18 of the strings 6a-6f. These disks are in turn connected to the lines 14 connected to the control chip 10 (shown here as 14a to 14f).

In this way, the strings 6a to 6f of the electric guitar 1 made of a conductive metal or wrapped with a conductive metal thread are electrically connected to the control chip 10.

On the tremolo system block 5 are in the FIGS. 5 (a) to 5 (d) attached rider 15 attached. About these run in the range of 16 designated rider inserts the pages. The in Fig. 5 (d) magnified illustrated rider insert is in the in Fig. 5 (a) shown riders in the in the Fig. 5 (a) used recess shown right. Since the riders 15 and the riding inserts 16 in an electric guitar 1 regularly made of metal and thus of a conductive material, in order to avoid a short circuit between the electrically contacted via the lines 14 strings, the riding inserts 16, over which the strings 6a run until 6f, be isolated from each other. For this purpose, the in Fig. 5 (a) Isolated with 21 designated areas.

In the FIGS. 7 (a) to 7 (d) are again details of the head 4 of the electric guitar 1 with the components arranged thereon to recognize the device according to the invention, wherein Fig. 7 (d) a detail enlargement of the in Fig. 7 (c) represented by D area.

In the FIGS. 8 (a) to 8 (d) are the mechanical units for adjusting the string tension consisting of the vertebrae 7, the wings 8 and the servomotors 11 once again detached from the head 4 shown. It can be seen that all these units are seated on a common board 22, which contains further control elements for controlling the servomotors 11. About the metallic and thus conductive vortices 7, the strings are electrically connected to corresponding tracks on the board 22.

The inventive device for automatic tuning of the electric guitar 1 operates as follows:

Pulling the push-pull potentiometer 13 activates the system. For this purpose, an in FIG. 9 used circuit shown, which will be described below.

The control chip 10 can now be issued by striking one of the strings commands. The sounds generated by striking the strings are converted by the pickup 12 into an electrical signal, which is converted in the controller to a frequency out. The controller stores certain preprogrammed commands which are called up to a frequency within a certain tolerance. In this way, for example, the program for tuning one of the strings, z. B. the e-string 6f, are called. If the program is activated, the control chip loads from a memory a reference frequency for this string, which serves as a reference frequency. The string is now possibly struck again, the actual frequency from the through the pickups 12 converted signal in the control chip 10 calculated and sent via the strings used as bus lines a signal to the board 22 or via this to the corresponding servo motor 11 for adjusting the string voltage to reach the desired frequency. In this case, the control chip 10 monitors the change in the frequency and, when the setpoint frequency is reached, issues a stop signal to the servo motor 11. In this way, all the strings can be tuned one after the other. As a routine for calculating the actual frequency from the electrical signal of the pickup a mathematical frequency filter is used, as this can calculate the frequency very quickly and reliably.

About an interface, not shown in the figures, the control chip 10 different frequency specifications for the strings are given, depending on what kind of mood is currently to be chosen (eg open tuning, etc.).

For the transmission of the control signals only two of the strings are needed. About two more strings, here the strings 6f (deep e-string) and 6e (a-string), the power supply for the board 22 and the servo motors 11 is spent in the head 4, so that its own power source is not needed there. The strings 6f and 6e are chosen to transmit the voltage, since the low e-string and the a-string are the thickest strings of the electric guitar 1 and thus are the least likely to break. Of the remaining four strings 6a to 6d, any two arbitrary bus lines can be freely controlled by the control chip 10. In this way, the system is redundant and can also work on one or even two broken strings of the strings 6a to 6d.

Light emitting diodes on the body 2, for example in the region of the pickups 12 below the strings 6a to 6f can indicate the state of the control chip 10 or the program sequence and so on simplify the handling of the device. Also here can be applied a "quick start", z. As with the display, by striking which of the strings 6a to 6f in which tone which commands are called. The frequencies associated with the instructions may be managed by the control chip 10 to match the current tuning of the electric guitar, that is, the user must always strike the same string with the same handle to fetch a command, no matter how the guitar and with it the string is tuned straight.

The power supply of the system takes place in this embodiment, externally via the amplifier cable, with which the guitar is already electrically connected to an amplifier. In the Fig. 9 shown Tonaderschaltung constantly monitors the internal resistance of the electric guitar 1. This is at normal play ready electric guitar 1 high. If the musician now pulls the push-pull potentiometer 13, it disconnects the pickups 12 from the jack socket for the amplifier cable and thus from the amplifier and switches on the control chip 10. As a result, the internal resistance of the electric guitar 1 decreases at least by a factor of 20. This detects the circuit and turns off the amplifier cable on the one hand from the amplifier so that the electric guitar 1 can be "muted" tuned. Furthermore, the circuit switches a supply voltage, which it can win, for example, from the power supply of the amplifier, but also an external power supply to the amplifier cable. This voltage is then supplied to the controller 10 and forwarded via the strings 6e and 6f in the head 4. Now, the device according to the invention can work. After completing the tuning or, for example, setting up the circuit or applying new data, the musician switches the push-pull potentiometer 13 back to the normal position. The internal resistance of the electric guitar 1 rises the now again connected to the amplifier cable pickup 12 again. This recognizes the tone circuit according to Fig. 9 and puts the signals from the amplifier cable back on the amplifier, the musician can continue to play.

LIST OF REFERENCE NUMBERS

1

electric guitar

2

corpus

3

web

4

head

5

Tremolo system block

6a-f

string

7

whirl

8th

wing

9

Pick Guard

10

control chip

11

servomotor

12

pickup

13

potentiometer

14

management

15

equestrian

16

riders use

17

drilling

18

thickening

19

shell

20

disc

21

area

22

circuit board

Claims (11)

1. Device for automatically tuning a stringed instrument (1), particularly a guitar, having:

   a) a detection device (12) for detecting a sound produced by striking a string (6a-6f) and for outputting a digital signal corresponding to the detected sound,

   b) a storage device for storing predetermined digital signals corresponding to a desired sound,

   c) a comparator for comparing the digital signal outputted by the detection device with a digital signal stored in the storage device and corresponding to the desired sound,

   d) an adjusting device (7) for changing the tension of the strings (6a-6f),

   e) at least one drive (11) for driving the adjusting device (7),

   f) a control unit (10) connected to the comparator and which by means of a variation established in the comparator between the signals representing the sound produced and the desired sound controls the at least one drive (11) by means of a bus line,
   the control unit (10) and the at least one drive (11) are placed in the stringed instrument (1) on opposite sides of the strings (6a-6f), considered in the longitudinal direction of said strings (6a-6f),

   characterized in that the bus line between the control unit (10) and the at least one drive is represented by at least one of the strings (6a-6d), which is made from a conductive material or is wound and/or coated with such a material.
2. Device according to claim 1, characterized in that the power supply of the at least one drive (11) also runs over at least one of the strings (6e, 6f), which is made from a conductive material or is wound and/or coated with such a material.
3. Device according to one of the preceding claims, characterized in that the control unit (10) is set up in such a way that it can be switched by receiving from the detection device a digital signal representing a sound within a tolerance range.
4. Device according to one of the preceding claims, characterized in that it has an interface for data exchange.
5. Device according to one of the preceding claims, characterized in that an adjusting device (7) with its own drive (11) is associated with each string (6a-6f).
6. Device according to one of the preceding claims, characterized in that, with its components detection device, storage device, comparator, adjusting device (7), drive (11) and control unit (10), it is completely integrated into the stringed instrument (1).
7. Device according to one of the preceding claims, characterized in that the string(s) (6a-6f) used as bus line(s) and/or current leads is freely selectable by the control unit (10), so that in the case of a defect in one string (6a-6f) the control unit (10) can choose an alternative string (6a-6f) as the bus line or current lead.
8. Device according to one of the preceding claims, characterized in that it is integrated into a guitar (1), preferably an electric guitar, the control unit (10) being placed on the body (2) of the guitar (1) and the adjusting device (7) and the at least one drive (11) are positioned at the upper end of the neck and the at least one drive (11) is connected by means of a bus line running along the neck and preferably via the strings (6a-6d) used as the bus line, to the control unit (10).
9. Method for automatically tuning a stringed instrument, in which:

   a) a string to be tuned is struck,

   b) the sound produced by the string is detected by a detection device and converted into a corresponding, first digital signal,

   c) the first digital signal is compared with a predetermined, second digital signal corresponding to the desired sound and from the comparison a calculation takes place in a control unit of the necessary change to the string tension,

   characterized in that in the control unit located on a first side considered in the longitudinal direction of the string a control signal is supplied to a drive connected to an adjusting device for adjusting the string tension and located on the opposite side considered in the longitudinal direction of the string by means of one or more strings of the stringed instrument made from a conductive material or wound and/or coated with such a material as bus line(s).
10. Method according to claim 9, characterized in that the first digital signal is prepared for further processing.
11. Method according to claim 10, characterized in that the frequency of the struck sound is determined from the first digital signal by means of a mathematical frequency filter and that the second digital signal corresponds to a predetermined frequency.

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