Abstract:
A combination of a capo with attached tuner having a sensor that picks up vibrations through the capo. The capo and tuner are connected together as a unitary accessory that is attachable along the neck of the guitar, in the manner of a conventional capo, but with the significant advantage of automatic and continuous visibility of the tuner display while tuning at a particular capo position and while pausing between songs.

Description:
[0001]    This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional App. No. 61/214,759 filed Apr. 28, 2009 for, “Tuner With Capo”. 
     
    
     BACKGROUND 
       [0002]    Guitarists use electronic tuners to adjust the instrument to a standard or selected reference pitch, and can place capos in various positions on the guitar neck to change the pitch of all the strings on the instrument. Capos allow the use of chords or different chord versions that would not be available to the musician if he tried to play them without the capo. The use of a capo enables the musician to use chords in positions that include more open string combinations. Open strings tend to have unique sound characteristics that are desirable in many musical situations. 
         [0003]    For ideal performance, the musician should re-tune the instrument after repositioning the capo. Many performers will take the stage with both a capo and a tuner in hand. This can be cumbersome to the artist and distracting to the audience. 
         [0004]    There are many types of tuners available on the market. Each one directly or indirectly senses the vibrating string, processes the sensed audio signal to determine the closest corresponding note, and then compares the actual pitch of the string to the target tuning pitch. A display interface shows the user if the note is flat or sharp and the user tunes the string until he gets and in-tune indication from the tuner display. Tuner displays are typically LED lights, an analog needle mete, or an LCD or other digital graphic display device. 
         [0005]    The audio signal from the instrument can be input into the tuner three ways. Some tuners have an input jack to directly wire the instrument to the tuner. Electric guitars or acoustic guitars with pickups (built in magnetic, piezo or microphone sensors) can be wired directly into the tuner. Some tuners use a built in microphone to pick up the signal. This is effective in quiet room conditions and for acoustic instruments. Noisy settings such as concert halls, studios, classrooms, and the like make it difficult to use a tuner in microphone mode. Some tuners clamp onto the instrument and utilize a built in sensor (usually a piezo type pickup) to pick up the vibrations in the guitar neck. 
         [0006]    A plugged in version is the most efficient as the input signal is directly coupled to the input circuit of the tuner and no ambient noise will affect the sensitivity or accuracy of the signal recognition. The disadvantages are that the tuner must be plugged in. This can be an inconvenience or simply not possible in certain stage, recording or practice conditions. Serious musicians are reluctant to run their signal through a tuner and then into their amplification devices because deterioration of the audio signal is always possible when additional devices are wired into the signal path. 
         [0007]    Tuners with a microphone input can be very effective also, but ambient room noise can confuse the input circuitry of the tuner giving erroneous readings. Using a microphone input tuner in a stage or studio environment is not practical. 
         [0008]    Clip-on type tuners that use a sensor and pick up the vibrations from the guitar body can be very effective. If designed properly they can be as sensitive as a direct wired version and can work well in noisy environments. They are also very convenient. They can be kept in a pocket or clipped on to the headstock of the guitar when not being used. 
       SUMMARY 
       [0009]    The inventive concept is to provide the combination of a capo with attached tuner having a sensor that picks up vibrations through the capo. The capo and tuner are connected together as a unitary accessory that is attachable along the neck of the guitar, in the manner of a conventional capo, but with the significant advantage of automatic and continuous visibility of the tuner display while tuning at a particular capo position and while pausing between songs. 
         [0010]    In one embodiment, the tuner can be purchased as a standalone item that is adapted to be retrofitted onto one or more standard capos. 
         [0011]    There are at least three benefits that the performer will realize using this invention. 
         [0012]    The performer will need only one tool on stage, in studio or while practicing. 
         [0013]    The tuner functions efficiently and accurately when used in conjunction with the capo. The clamping force of the capo makes a strong connection with the guitar neck and efficiently transmits the string vibrations to the sensor in the tuner that is mounted on the capo. Ambient noise does not degrade the tuning. Tuning can be efficiently achieved upon placing the capo anywhere on the neck. The capo can also be stored on the headstock when not being used as a capo. The tuner will function perfectly as a stand alone, clip-on type tuner when stored on the headstock. 
         [0014]    It is very common for an artist to make minor adjustments in tuning after installing or moving a capo to a different position on the guitar neck. Having the tuner right at the capo where his hand is during installation will make it very convenient and easy for him or her to re-tune quickly and perfectly after each move of the capo. It will not be necessary to clip on a tuner or reach up to the headstock if he is using a clip-on type tuner to turn the unit on. The artist can capo the strings and tune them very quickly without having to interrupt his performance. 
     
    
     
       DRAWING 
         [0015]      FIG. 1  shows one type of known professional quality capo; 
           [0016]      FIG. 2  shows an embodiment of the present invention as a combination of a tuner integrated with a capo of the type shown in  FIG. 1 , with the open side of capo facing to the left and the tuner on the right; 
           [0017]      FIG. 3  shows the combination of tuner and capo of  FIG. 2 , but from a different view in which the open side of the capo faces to the right and the tuner is on the left; 
           [0018]      FIG. 4  shows the combination capo and tuner of  FIG. 4 , installed on the headstock of a guitar; 
           [0019]      FIG. 5  shows the combination of capo and tuner of  FIG. 3  installed on the neck of a guitar; 
           [0020]      FIG. 6  is a view similar to  FIG. 2 , partially cut away to show how the tuner is connected to the capo; 
           [0021]      FIG. 7  is a view of the device of  FIG. 6 , from right; and 
           [0022]      FIG. 8  is a schematic of a tuning circuit suitable for implementing the present invention. 
       
    
    
     DESCRIPTION 
       [0023]      FIG. 1  shows a capo as described in U.S. Pat. No. 6,008,441, the disclosure of which is hereby incorporated by reference. The neck  10  of a guitar (including strings  10 ′) is clamped between top jaw  11  and bottom jaw  12 . The jaws ( 11  and  12 ) are both preferably lined with elastomeric pads ( 13  and  14 ), pad  13  assuring that all of the strings are clamped to the neck, and both pads preventing the neck from being marred. The bottom jaw  12  wraps partially around, and is pivotally attached to the shank of top jaw at pin  15 . Torsion spring  16  bears against the foot  17  extending from the shank of top jaw  11  and the inside of bottom jaw  12 , tending to close the jaws, and thereby apply clamping pressure to the guitar neck. 
         [0024]    The force to open the jaws is provided by a hand operated two bar toggle type linkage comprising link  18  and link  19  on graspable arm  22 . While link  18  and link  19  comprise a toggle type of linkage, the motion is such that the linkage does not actually toggle, since the jaws are fully open before the two elements which form the toggle are aligned. This type of linkage is used to provide a reducing force requirement as the jaws are opened, but the links do no cross over, i.e., the force does not go to zero and become negative, as in usual toggle applications. 
         [0025]    To open the capo, finger pressure is applied to arm  22  (which projects from link  19 ) and arm  21  (which projects from jaw  11 ). As graspable arm  22  approaches arm  21 , link  18  rotates to become closer to aligning with graspable arm  22 , and the opening force required correspondingly decreases, even while the spring  16  exerts increasing force. Hence, relatively little actuating force is required maintain the capo open, and the musician can position it on the instrument without having to exert excessive force. 
         [0026]    In the combination  20  of capo and tuner according to  FIGS. 2-7 , the torsion spring has been replaced by a coil spring  21  that extends perpendicularly from the lower jaw  12  in parallel with an extension of the shank  11 ′ of the upper jaw  11 , and the upper end of link  18  is connected to a short stem  12 ′ extending from lower jaw  12 . The tuner  23  has a front end that firmly receives the shank  11 ′ such that vibrations in the shank can be transmitted to a sensor within the tuner body  25 . A tuner circuit is located within the body and a tuner display, such as a plurality of lights, is visible on the body. The tuner body preferably extends from the shank  11 ′ in parallel with the spring  21 . 
         [0027]      FIGS. 2-3  show the inventive combination  20  in different views while off the instrument and  FIGS. 4-5  show it while mounted in the alternative play/tuning positions on the headstock  39  and the neck  40  of the guitar, respectively. 
         [0028]    As is well known, the headstock  39  has a top surface  41  on which the strings (not shown) engage heads or pegs  42 , which can be turned by respective tuning keys or winders  43 . The neck  40  has a fret board  44  on its upper surface, with spaced apart frets  45 . 
         [0029]      FIGS. 6 and 7  show details of how the tuner  23 , spring  21 , and spring tension adjusting bolt  26  are preferably configured in a compact yet functional manner. The tuner body has an integral boss or the like  27  extending through the axis of the coil spring  21 . A bore  28  in the boss receives the shank  29  of bolt  26 , with the bolt head  30  accessible at one end of the boss and the threaded tip  31  of the bolt passing through a threaded insert  32  at the other end of boss. The tip of the bolt carries a disc  33  or the like that provides a seat for the coil spring. The other end of the spring bears on a seat  34  that is fixed with respect to the lower jaw  12 . The bolt  26  can thus adjust the neutral length of the spring and the leverage forces associate with the linkages that open and close the capo jaws. In this embodiment, there is no need for the upper jaw  11  to have a foot (see item  17  of  FIG. 1 ) to rigidly support one end of the spring, because the equivalent function is provided by the seat  33  which is supported by the shank  11 ′ of upper jaw  11  through the intermediary structure of the tuner  23  and bolt  26 . The tuner  23  is held in place by the close fit of the extension into the body  25  of the upper jaw shank  11 ′ and the connection of the threads of the bolt  26  to the threaded insert  32  which is rigidly connected to the boss  27 . 
         [0030]    The tuner  23  has a sensor or transducer such a piezo device  35  to detect mechanical vibration that originates with a plucked string and is transmitted through the capo, especially the upper jaw  11  via the shank  11 ′, to the tuner  23 . The detected waveform is analyzed by a printed circuit board or the like  37  powered by battery  36 , and the resulting tuning figure of merit is displayed as by a light pattern at  38 . As can be appreciated from  FIGS. 4 ,  5  and  6 , the light pattern is readily visible to the artist when the capo is mounted to the neck or headstock of the guitar. The figure of merit typically indicates whether the string is too sharp or too flat, and may also indicate the degree of deviation from the target pitch. 
         [0031]      FIG. 8  shows a representative tuning circuit for analyzing mechanical vibration of a stringed instrument. One of ordinary skill in the relevant field can readily incorporate this or other known tuner circuits into the tuner described above.