WO1995008819A1

WO1995008819A1 - Improved electronic tuning device

Info

Publication number: WO1995008819A1
Application number: PCT/US1994/010576
Authority: WO
Inventors: Gary Miller; Doran M. Oster; Charles G. Crampton
Original assignee: Sabine Musical Manufacturing Company, Inc.
Priority date: 1993-09-22
Filing date: 1994-09-22
Publication date: 1995-03-30

Abstract

An electronic tuning device includes a display (22) with a single row of LED's (24) corresponding to musical notes wherein the sensing (114) of a fundamental frequency of an input tone causes the operation (120, 124, 128) of the corresponding LED to indicate the nearest note. Additionally the LED is operated in manner, such as blinking (126) proportionally to the variation from the note and/or producing different colors, such as green, red and amber, to indicate (118, 122) in-tune and out-of-tune conditions. In one variation, a double back adhesive rubber pad (56) can be used to removably mount the tuner on an instrument, so that the device can simply pull off the musical instrument to make it ready for its next use. The rubber pad serves to attenuate high frequency mechanical vibrations of the musical instruments thus improving the accuracy and versatility of the unit. In one embodiment, the display (154) is mounted externally on the musical instrument (152) while the tone sensing circuitry (150) is mounted inside the musical instrument such as within the sound box of an existing guitar. In another variation, the electronic tuning device has selectable width tuning ranges wherein selected pairs of the LEDs (24) are activated, such as being turned on, blinked or flashed, so that the spacing between each activated pair of LEDs indicates the width of the tuning range during a range indicating mode.

Description

IMPROVED ELECTRONIC TUNING DEVICE

TECHNICAL FIELD

The present invention relates to tuning devices for musical instruments and singers, and more specifically, to electronic tuning devices for indicating the tuning of almost any type of musical instrument including band and orchestra instruments such as wind instruments along with stringed percussive instruments like guitars, pianos, harps, etc.; electronic musical instruments which have microphone pickups and amplifiers to generate acoustical sound vibrations in the air by speakers; and musical notes produced by a singer.

BACKGROUND ART

Traditional tuning of instruments is often done with one or more tuning forks, or other accurate tone sources, and a trained ear. In this process, the artisan often uses the phenomenon of "beats" to fine tune the instrument. A beat is an apparent oscillation of the loudness of a perceived tone when that tone is produced by two simultaneous tones of nearly, but not exactly the same frequency. Beats occur at a frequency equal to the difference between the two generating frequencies. For example, if a tuning fork is vibrating at a frequency of 440 Hz (440 cycles per second or in musical terms an A note) and a piano string is simultaneously vibrating at a fundamental frequency of 443 Hz, a definite rising and falling in the volume of the perceived tone will occur at a rate of three cycles per second. As the two tones approach the same frequency the beat frequency will reduce to zero. At a beat frequency of zero there is simply no variation in the volume of the combined tone. When a beat frequency occurs there is no way to tell which of the two tones (the tuning fork ' or the piano) is the higher frequency. When a three Hertz beat occurs the technician can only be sure the string is three Hertz off from the standard tone. Whether the string is sharp or flat still had to be determined by ear. Many times a trial adjustment was made and if the beat got faster, the knowledge was gained that the adjustment was in the wrong direction. The traditional method of tuning instruments left a lot to be desired and was entirely dependent on the skill of the tuning technician.

An electronic tuner for musical instruments has been marketed by Sabine Musical Manufacturing Company, Inc. of Gainesville, Florida since about 1987. For tuning traditional musical instruments, i.e. non-electronic instruments, the tuner is set on a table top and uses a built-in microphone to sense tones produced by the musical instruments. For tuning electronic instruments, a signal output from the instrument or amplifier is directly connected by a cable to the electronic tuner. The LED display of this prior art tuning device consists of a bottom row of twelve lights corresponding to the twelve musical notes in an octave, i.e. A, A# (Bb) , B, C, C# (Db), D, DU (Eb), E, F, F# (Gb), G and G# (Ab) . A separate top row of three lights is provided for indicating flat, in-tune or sharp tuning conditions, respectively. One of the twelve LEDs in the bottom row is lit to indicate the note of the incoming tone while one LED in the upper row is lit to indicate whether the incoming tone is in-tune, sharp (above the in-tune range) , or flat (below the in-tune range) . The flat and sharp error indicating lights are operated at blink rates proportional to the magnitude of error. During tuning the musician must constantly monitor both rows of LED's, and in the absence of such concentration, a change to the wrong note can be overlooked resulting in tuning of the instrument or string to the wrong note.

Electronic tuning devices of the above type work best with the electronic instruments where electrical signals from the electronic instruments are fed directly into the tuning device circuitry. Use of a microphone to pickup the tone from air-transmitted sound from acoustic instruments is susceptible to error or difficulty in tuning due to ambient noise also picked up by the microphone. Such ambient noise or interfering tones are subject to being confused by the tuning device with the tone being transmitted by the instrument resulting in failure or difficulty in obtaining a tuning indication from the tuning device.

Also electronic tuning devices of the above type generally have a relatively small in-tune range or window, for example plus or minus three or four cents, in order to prevent annoying beat frequencies and dissonance between tuned instruments. Such tuning devices are most suitable for string instruments such as guitar, piano, harp, etc. However, these tuners are generally not used in tuning band and orchestra instruments such as wind instruments including brass instruments and woodwinds like single and double reed instruments and flute type instruments. Only highly experienced or talented band and orchestra musicians can hold a tone within plus or minus four cents on wind instruments. There is a need for beginners and students in bands or orchestras, such as high school bands and orchestras, to have a low cost tuner producing a visual indication of the in-tune or out-of-tune condition of their instruments, particularly those playing wind instruments. Additionally there is a need for a similar tuner for indicating musical notes produced by singers during practice and the deviation of the vocal notes from standard musical notes. The prior art, in U.S. Patent 3,861,266, discloses a musical tuning instrument for persons of lesser skill, such as members of high school bands. The tuning instrument has selector switches for setting the frequency (note) and sensitivity. When sensitivity is set at the most sensitive position, a pattern of eight lit LEDs in a circular array of sixteen LEDs rotates once per second when the incoming tone is exactly one Hertz greater or less than the set frequency. At the least sensitive position, the one second rotation of the pattern occurs when the incoming tone is sixteen Hertz greater or less than the set frequency.

DISCLOSURE OF THE INVENTION

The invention is summarized in an improved electronic tuning device for a musical instrument wherein the tuning device has a display with a row of light sources corresponding to musical notes; one of the light sources being operated to indicate the nearest musical note to a determined fundamental frequency of musical tone generated by the musical instrument; and the operation of the operated light source being controlled to indicate any deviation of the determined fundamental frequency from the nearest musical note. A transducer converts the musical tone played by the musical instrument into electrical signals from which is determined the fundamental frequency of the musical tone. The nearest musical note to said fundamental frequency of said musical tone is computed and the corresponding light source is operated to indicate both the nearest musical note and the deviation.

Accordingly, it is a principal object of the invention to provide an improved musical instrument tuning device which is easier for the user to operate and tune a musical instrument to the correct musical note.

Another object of the invention is to provide an electronic tuning device with a timed power shutoff feature which prevents unintentional discharging of the battery power source and which can be readily disabled for extensive tuning procedures.

Still another object of the invention is to provide a musical instrument tuning device with selectable in-tune ranges enabling use by beginners, students and accomplished musicians to tune band and orchestra instruments and voice.

Yet another object of the invention to provide an electronic tuning device with a single row of display lamps, such as light emitting diodes (LEDs) , which indicate the width of a tuning window along with the frequency or note of a incoming tone and its in-tune or out-of-tune condition.

One advantage of the invention is that a single light emitting source in a row of light emitting sources can be monitored to determine what musical tone is being played and whether that tone is sharp, flat, or in-tune with the desired musical note.

Another advantage of the invention is that the spacing between a pair of energized light emitting sources in a row of light emitting sources indicates the width of a set in-tune range. Still another advantage of the invention is that an in-tune range or window is selected by depression of a calibration or range switch to step a tuner through the selectable in-tune ranges.

Additional features of the invention include the provision of three-color light sources for indicating notes in a scale of notes wherein the color indicates sharp, flat and in-tune conditions of the notes; the provision of blinking light sources for indicating notes in a scale of notes and deviations of tones from the notes; and automatic power off with simple disablement of the power off feature.

Other objects, advantages and features of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is top plan view with a portion broken away of an electronic tuning device in accordance with one embodiment of the invention. Fig. 2 is a front elevational section view of one variation of the electronic tuning device of Fig. 1. Fig. 3 is a block diagram of electrical circuitry in the electronic tuning device of Figs. 1 and 2.

Fig. 4 is step diagram of one variation of a program employed in a microprocessor in the circuitry of Fig. 3. Fig. 5 is a partial perspective view of a variation of the electronic tuning device in accordance with the invention.

Fig. 6 is a front elevational section view of a another variation of the electronic tuning device of Fig. 1.

Fig. 7 is a step diagram of another variation of the program for employment in the microprocessor in the circuitry of Fig. 3.

Fig. 8 is a step diagram of a subroutine called by the program in Fig. 7.

Fig. 9 is a diagram of a row of LEDs with corresponding note indicia in the electronic tuning devices of Figs. 1, 2 and 6.

Fig. 10 is a table listing pairs of blinking lights in the light row of Fig. 9 with the corresponding in-tune range set by the electronic tuning device according to the program variation of Fig. 7.

BEST MODES FOR CARRYING OUT THE INVENTION

As shown in Figs. 1, 2 and 6, an electronic tuner for use in tuning a musical instrument is constructed in accordance with one embodiment of the invention and includes a casing 20 in which is mounted a display, indicated generally at 22, with a row of light sources, for example, twelve red-green dual light emitting diodes (LEDs) 24 which correspond to respective musical notes A, Al* (Bb), B, C, CU (Db), D, DK (Eb) , E, F, Fft (Gb), G and G# (Ab) . The tuner includes an electronic circuit 28, Fig. 3, mounted in the case 20 wherein a pickup head such as a microphone or a transducer 30 converts an incoming tone from a musical instrument into electrical signals which are analyzed by a microprocessor 38 which operates the LED display 22. The microprocessor 38 determines the fundamental frequency of the incoming tone, computes the nearest musical note, and operates the corresponding light source 24 in the display 22 in manner indicating the in- tune or out-of-tune condition of the incoming tone. For example, the microprocessor 38 controls the operated light source to select a color indicating an in-tune condition or a deviation such as flat or sharp condition of the tone from the nearest musical note and\or to blink the light source proportional to the deviation of the tone from the nearest musical note. Optionally, the signals from the pickup head 30 are amplified by an amplifier 32, filtered in a frequency response amplifier 34, and detected by a zero crossing detector 36 to provide a suitable waveform for analysis by the microprocessor 38; many other circuits are known in the art to produce similar or different waveforms suitable for analysis.

In another variation of the electronic tuning device, the processor 38 includes a second mode for operating the LEDs in the display 22 to indicate the width of the in- tune range to which the tuner is set. One example of indicating a set range selected from several in-tune ranges is illustrated in the table of Fig. 10 wherein pairs of the LEDs 24, see also Fig. 9, are turned on, flashed or blinked; the spacing between the activated LEDs indicates the set in-tune range so that the broadest in- tune range is indicated by the LEDs A and GU on the ends of the row 22 and the narrowest range is indicated by the two innermost LEDs D and D|l. Aspiring musicians playing wind instruments in bands and orchestras can improve their intonation by playing long steady tones while watching a tuner in the second mode of operation. By practicing various techniques during tuner operation, the musician can determine which techniques make the instrument more sharp and which make the instrument more flat. Beginning students are challenged to keep their instrument in tune even with the widest window. As proficiency improves, narrower windows are selected to further improve intonation. In time, students become accustomed to hearing the correct pitches and to experiencing the necessary techniques needed to play in tune. The assistance provided by watching the tuner during long tones make learning to play a band instrument easier and faster.

Referring to Figs. 1-10, a specific example of one embodiment with examples of a few of the many possible variations and modifications is illustrated. More specifically in Figs. 1, 2 and 6, the casing 20 has approximate outside overall dimensions of about 3 inches x 1.5 inches x 3/8 inch (7.6 centimeter x 3.8 centimeter x 1 centimeter) . Casing 20 is made up of top member 50 with side walls 52 and a bottom plate 54 suitably secured in the side walls. Casing 20 is preferably molded from a durable plastic material. Side walls 52 extend slightly below the bottom edge of floor plate 54 to provide protection for the edges of an adhesive elastic pad 56, Fig. 2, or rubber feet 57, Fig. 6, which are secured on the bottom surface of the floor plate 54. The pad 56 can be a conventional foam rubber or polyurethane tape such as that known as visco-elastic urethane tape which has adhesive on both sides. The sticky pad 56 has an exposed releasable pressure sensitive adhesive layer 80 which adheres to any smooth relatively flat and clean surface upon which it is pressed. The releasable nature of the adhesive 80 allows the tuning device to be removed from the surface to which it is stuck with the application of a moderate amount of lifting force.

The top and bottom members 50 and 54 together with the side walls 52 define an enclosed box structure within which are mounted the electronic components such as the circuit 28 of Fig. 3. A circuit board 60 is mounted in the casing 20 and serves as a support and connection bus for the row of twelve two-color LED's 24 which selectively illuminate correspondingly labeled portions of a frosted face plate 62. Alternatively the illumination may be acco nlished in many different ways such as by providing small cutouts in the top plate, by making portions of the top plate transparent, or many other ways. As shown in Fig. 6, the individual LED's may be labelled with indicia such as:

A O B C O D O E F O G O where the letters represent white keys on a piano and the "O" symbols represent the black keys. Of course the exact form of labeling is arbitrary and a matter of design choice. The scale does not have to start with A but can start with any other note such as C which would then end with B.

A battery 64, shown hidden in Fig. 1, supplies power for the electronic circuit. A door 66, Figs. 2 and 6, is provided in the bottom plate 54 for enabling the battery 64 to be replaced. Top member 50 also has two openings for mounting push button switches 70 and 72. Suitable indicia identifying these switches are formed on top 50. For example, the switch 70 can be labeled as a calibration or range switch and the switch 72 can be labeled as a power switch. Push buttons 70 and 72 are designed to make contact with inner spring biased switch elements 74 and 76, respectively, when manually depressed. As can be seen in Figs. 2 and 6, inner switch elements 74 and 76 are supported on the circuit board 60. The pickup head or transducer 30, in Fig. 2, is centrally mounted on the bottom side of bottom plate 54 under the rubber pad 56. The rubber pad 56 dampens higher frequency components to serve as a high frequency filter which reduces the magnitude of harmonics of the tone being analyzed. This enables the circuit to more readily determine the fundamental frequency of the tone. In Fig. 6, the pickup head or transducer 30 is centrally mounted on the inside of the top member 54.

One example of a program for operating the processor chip 38 of Fig. 3 is illustrated in Fig. 4. Operation begins at the step 100 when the power switch 72 is closed and proceeds through power up initialization 102 to step 104 where it is determined if the power switch 72 is depressed. The power switch must remain depressed sufficiently to distinguish from an incidental induced signal; otherwise the program branches to step 106 and a power down sequence.

If step 104 is true, the program branches to step 108 where it is determined if the calibration switch 70 is also depressed. If the calibration switch is not depressed, a power shut down timer is started in step 110. This timer will later power down the tuner after a predetermined time, for example about two minutes, ten minutes or other time period. Normal operation of the power switch 72 initiates the timer which automatically shuts down the tuner after the set delay. When the calibrate switch 70 is depressed before the power switch 72 is depressed and the calibrate switch is held depressed as the power switch is depressed, the program will bypass the timer initiating step 110 so that the tuner can operate continuously. Continuous operation is desirable for tuning some instruments, for example, harps, pianos, etc. , where more time is needed for tuning than is provided by the standard turn off delay. After timer initiation or bypass, the program waits in step 112 for the power and calibration switches 70 and 72 to be released. The processor then begins procedure 114 to determine the fundamental frequency of the input signal from the transducer 30. The procedure 114 is a conventional procedure where the arriving output of the zero crossing detector 36 is used by the processor 38 to determine the fundamental frequency. For example, the fundamental frequency can be determined by first determining the appropriate octave and then determining the cent value (logarithmic) relative to the note "A" in that octave. After determining the fundamental frequency of the tone, the nearest standard note on a stored scale of notes is determined in step 116. Alternatively, step 116 can determine the nearest note by a conventional algorithm based upon frequency or cent value of one note, for example "A", in the corresponding octave. Next in step 118, it is determined if the sensed frequency is above the nearest standard note by more than a predetermined value, such as three cents. If step 118 is true, the red LED of that standard note is turned on in step 120. Otherwise the program proceeds to step 122 where it is determined if the sensed frequency is below the nearest standard note by more than the predetermined value, such as three cents. If step 122 is true the program will proceed to step 124 where both the red and green LEDs corresponding to the nearest standard note are turned on. The mixture of red and green gives an amber color. From step 120 or step 124, the program proceeds to step 126 where the corresponding LED or LEDs are turned off and on at a blink rate which is proportional to the absolute value of difference of the tone frequency from the nearest standard note. If steps 118 and 122 are both false, the program in step 128 turns on the green LED; i.e., the green LED indicates that the fundamental frequency of the tone being sensed is within ± three cents of the corresponding note. Additionally the green note is maintained on steady and not turned on and off at any blink rate to contrast the green in-tune condition from the out-of-tune conditions of sharpness (red) and flat (amber) .

After operating the appropriate LED, the program in step 130 determines if the timer was started back in step 110 and if so whether the time has now expired. If the timer is active and the time has expired the program proceeds to the power down procedure 106 where any LEDs are turned off. Additionally in the power down procedure 106, the energization of the processor is placed in a minimum or quiescent power condition, and where appropriate, other circuit components are turned off. When step 130 is false, the program in step 132 determines if the power push button switch 72 has been operated. If it is now pressed the unit is powered down by the power down procedure 106. Thus the power switch acts as a toggle with the first press turning the unit on and a successive depression turning the unit off.

If the unit is not turned off by a successive depression of the power switch in step 132, the program proceeds to step 134 where the calibration switch 70 is again checked. If the calibrate switch 70 is depressed, the program branches to step 136 where the fundamental frequency of the tone being input is determined similar to step 114. Then in step 138 the scale used in step 116 is adjusted to correspond to the sensed fundamental frequency. Alternatively an offset, in either frequency or cents, can be determined in step 138 for use in step 114 or 116. The calibration steps 136 and 138 are designed to enable the tuning device to be calibrated on a second instrument, for example a piano, and then used to tune a first instrument, for example a guitar, to be in- tune with the second instrument.

If the calibration switch 70 is not found to be depressed in step 134, the program loops to the determine frequency step 114. Thus if a musician is tuning an instrument and does not press either push button switch 70 or 72 after initially starting operation of the tuning device, the device continuously loops and corrects the settings of the LED's as the musical instrument is tuned or until the timer, if set, expires. Another example or variation of a program for operating the processor chip 38 of Fig. 3 is illustrated in Fig. 7. Steps similar to the steps of Fig. 4 are indicated by the same numeral and only the difference in operation is described below. In the initialization step 102, the in-tune range is set to the widest range, for example, from plus 49 to minus 49 cents as shown in Fig. 10 corresponding to LEDs A & G}t, Fig. 9. Alternatively, the set in-tune range can be set equal to the in-tune range at which the tuner was set when last turned off.

In step 111 following initiation of the automatic shutdown timer or timer-1, the tuner indicates the normal timer power shut-down mode, for example by momentarily turning on the green DJi LED such as for one to three or more seconds. When the calibrate switch 70 is depressed to provide continuous operation, the tuner in step 109 indicates the continuous mode, for example by momentarily turning on both the green C# and D|l LEDs such as one to three or more seconds.

After sensing the open condition of the switches in step 112, the program proceeds to step 113 where the program calls a range subroutine illustrated in Fig. 8. In step 170 of the range subroutine, the lights or LEDs illustrating the current in-tune range setting are turned on. For example, the table in Fig. 10 lists six in-tune window widths or ranges along with the corresponding LEDs used to indicate each range. The spacing between the activated LEDs indicates the width of the set in-tune range. If the current in-tune range is ±49 cents, then the LEDs A and G#, Fig. 9, are turned on.

In the next step 172, a range display timer or timer-2 is set. The range display timer is set for a duration equal to a selected time for display of the in- tune range, for example about three seconds or any other shorter or longer desirable time period for indicating the in-tune range. From step 172, the program proceeds to step 174 where the program waits until the range switch 70 is found open whereupon step 176 determines if the time set in range display timer has expired. If true the program returns to the step in the main program of Fig. 7 following the point where the range subroutine was called. Otherwise the program proceeds to step 178 where it is determined if the calibration or range switch 70 is closed. When the switch 70 is open, the program continues to cycle through steps 176 and 178 until timer-2 expires. Thus when the tuner is powered up, the in-tune range is displayed for the duration of timer-2.

The musician can change the in-tune range by pressing the range push button switch 70 during the display of the in-tune range. Closing the range switch 70 causes the program to branch from step 178 to step 180 where it is determined if the present set in-tune range is the narrowest range in the possible in-tune ranges, for example plus or minus five cents in the table of Fig. 10. If false, the program in step 182 selects the next narrower range as the set in-tune range. Contrarily if true, the program in step 184 selects the broadest in-tune range such as plus or minus forty-nine cents in the example of Fig. 10. From step 182 or step 184, the program goes back to step 170 to change the in-tune range displayed by the display 22 to the new setting. Steps 172, 174, 176 and 178 are then repeated. By repeatedly depressing and releasing the range switch 70, the musician can successively select narrower tuning ranges until the narrowest range is selected whereupon the next operation of the switch 70 selects the broadest in-tune range.

Referring back to Fig. 7. after return from the range subroutine in step 113, the program in step 190 determines if the calibration or range switch 70 is closed. From the main program of Fig. 7, the musician by pressing the range switch 70 causes the program to branch from step 190 to step 192 which calls the range subroutine of Fig. 8 to display the in-tune range at anytime even when the tuner is detecting a tone. Furthermore re-pressing the range switch in rapid succession (before timer-2 expires) results in changing the in-tune range. As described above, the musician can thus select successively narrower in-tune ranges while timer-2 remains active in the range subroutine until the narrowest range is reached whereupon the next depression of the range switch selects the broadest range. From step 192 of Fig. 7, the program returns to the step 190. When the range switch is found open in step 190, the program in step 194 determines if a tone is being sensed, for example, by determining if the output of the zero crossing detector 36 is a repeating pattern. When an incoming tone is present, the processor then proceeds through the routine represented by steps 114, 116, 118, 120, 122, 124, 126, 128, 130 and 132, as previously described, except that in step 118, it is determined if the sensed frequency is above the nearest standard note by more than the set upper limit of the in-tune range, for example see Fig. 10 wherein the set upper limit is one of the limits of plus 49, 40, 30, 20, 10 or 5 cents above the standard note. If step 118 is true, the red LED of that standard note is turned on in step 120. Otherwise the program proceeds to step 122 where it is determined if the sensed frequency is below the nearest stan< =rd note by more than the set lower limit of the in-tune range, such as below the standard note by more than minus 49, 40, 30, 20, 10 or 5 cents. If step 1^. is true the program will proceed to step 124 where both the red and green LEDs corresponding to the nearest standard note are turned on. If steps 118 and 122 are both false, the program in step 128 turns on the green LED; i.e., the green LED i~dicates that the fundamental frequency of the tone being sensed is within the set range (plus or minus the corresponding window width of Fig. 10) of the nearest musical note.

When no incoming tone is detected in step 194, the program branches to step 196 where the corresponding red LEDs of LEDs 24 for the set range, such as in the table of Fig. 10, are flashed or blinked. The dual blinking red LEDs indicate the idle condition, and the spacing between the blinking LEDs indicates the set in-tune range. A slow blink rate, such a one second or other long duration delay between flashes, is easily recognized as the idle state where no incoming tone is sensed.

Fig. 5 shows a variation of the tuning device wherein a casing 150 of the tuning device is mounted directly on the instrument, such as within the sound box of a guitar 152. This variation differs from the embodiment of Figs. 1-4 in that the row of twelve two-color LED's 24 are mounted in a separate narrow case 154 which is mounted on the upper surface 156 of finger board 158 of the guitar 152. The LED's 24 are connected to the control electronics in case 150 by means of a cable and plug assembly 160. Power switch 72 has also been placed in the narrow case 154 adjacent the LED's 24. Case 150 is attached, for example, to the support board 162 on the interior of guitar 152. Screw 164 is show as a semi¬ permanent attachment means for case 150 in this embodiment as opposed to the sticky pad attachment used in the embodiment Fig. 2. The narrow case 154 can be secured to the finger bar by an adhesive, screw, or any other suitable fastening means or can be embedded in some portion of the instrument, such as in the finger board.

Since many variations, modifications and changes in detail can be made to the above described embodiments, it is intended that the foregoing description and the accompanying drawings be interpreted as only illustrative and not as limiting to the scope and spirit of the invention as defined in the following claims.

Claims

1. An improved electronic tuning device for a musical instrument comprising; a transducer (30) for converting an acoustic tone played by the musical instrument into electrical signals; frequency determination means (114) for determining a fundamental frequency of said electrical signals and thus determining a fundamental frequency of said musical tone; computing means (116) for computing a nearest musical note to said fundamental frequency of said musical tone; a display (22) including a row of individual light sources (24) corresponding to respective musical notes; means (120, 124, 128) responsive to the computing means for operating a light source in the row of light sources corresponding to the computed nearest musical note; and means (118, 122) responsive to a deviation of said fundamental frequency of said musical tone from the computed nearest musical note for controlling the operated light source to indicate the deviation whereby the operated light source indicates both the nearest musical note and the deviation.

2. The improved electronic tuning device of claim 1, wherein said controlling means blinks (126) the operated light source proportionally to the deviation of said fundamental frequency of said musical tone from the computed nearest musical note.

3. The improved electronic tuning device of claim 1 or 2, wherein each of said light sources (24) is adapted to selectively produce at least two colors, and said controlling means operates the operated light source to produce one color when said fundamental frequency of the musical tone is above the computed nearest musical note and operates the operated light source to produce a second color when said fundamental frequency of the musical tone is below the computed nearest musical note.

4. The improved electronic tuning device of claim 3, wherein each of said light sources (24) is adapted to produce three colors, and said controlling means operates the operated light source to produce a third color when said fundamental frequency of the musical tone is substantially equal to the computed nearest musical note.

5. The improved electronic tuning device of claim 4 wherein each of said light sources (24) includes red and green light emitting diodes, one of said three colors being red, another of said three colors being a combination of red and green, and the other of said three colors being green.

6. The improved electronic tuning device of claim 5 wherein the first color is red, the second color is a combination of red and green and the third color is green.

7. The improved electronic tuning device of claim 5, wherein the display (22) comprises twelve red and green light emitting diodes (24) corresponding to the twelve musical notes of a standard musical scale.

8. The improved electronic tuning device of claim 1, further comprising a power switch (72) for turning the tuning device on and off; timing means (110) initiated by the power switch turning the tuning device, on for automatically turning the tuning device off after a predetermined delay; a calibration switch (70) ; calibration means (138) responsive to operation of the calibration switch for calibrating musical notes in accordance with said fundamental frequency of the musical tone; and timing disable means (108) responsive to simultaneous operation of said power switch and said calibration switch for disabling the timing means to enable an indefinite duration of operation of the tuning device.

9. The improved electronic tuning device of claim 1, further comprising a case (50, 54) enclosing the electronic tuning device; and an elastic adhesive pad (56) on the case for removably mounting the tuning device on a body of the musical instrument so that acoustic vibrations from the musical instrument operate the tuning device and wherein the resilient adhesive pad attenuates harmonics of said fundamental frequency of said musical tone.

10. The improved electronic tuning device of claim 1, wherein the device is adapted for mounting on a musical instrument (152) having a finger board (156) ; and further comprising a first case (150) enclosing the transducer means, the frequency determination means, the light source operating means, and the operated light source controlling means; a second narrow case (154) supporting the row of individual light sources (24) and adapted to be mounted on an upper edge surface of the finger board; and a cable (160) connecting the circuitry in the first case to the light sources in the second case.

11. The improved electronic tuning device of claim 1 further comprising: in-tune range setting means for selecting one of a plurality of different width ranges for the musical instrument to be in-tune; and second mode means (170) for operating the individual light sources in the display to indicate the selected in- tune range.

12. The improved electronic tuning device of claim 11 wherein the second mode means operates pairs of light sources in the row of light sources (22) so that the spacing between each operated pair of light sources is indicative of the selected in-tune range.

13. An electronic tuning device as claimed in claim 12 wherein the second mode means blinks (196) each operated pair of light sources.

14. An electronic tuning device as claimed in claim 11 wherein the in-tune range setting means includes a push button switch (70) , and means (178) responsive to depression of the push button switch for selecting another of the plurality of in-tune ranges.

15. An electronic tuning device as claimed in claim 14 wherein the depression of the push button switch (70) selects (182) the next narrower in-tune range except when the present in-tune range is the narrowest range and then the broadest in-tune range is selected (184) .

16. An electronic tuning device as claimed in claim 14 wherein the second mode means is operated by a first depression (190) of the push button switch (70) , and includes a timer (172) which is set by operation of the second mode means; and wherein the in-tune setting means (178, 180, 182, 184) is operable only during the operation of the timer.

17. An electronic tuning device as claimed in claim 16 wherein the second mode means is momentarily operated (113) during power up of the tuning device.