The present invention concerns a chromatic tuner for musical instruments, which measures the acoustic frequency produced by the instrument to be tuned, and displays quantities characterising the tuning accuracy in a watch, for example a wristwatch.
Musical instruments generally require periodic tuning, to ensure that they produce consistent sounds. This is commonly achieved by a technique consisting in using a tuning fork with note A as the fourth octave reference note at 440 Hertz.
In order to ensure that the note is exactly accurate independently of parameters that can distort the characteristics of a tuning fork, such as humidity and temperature, there now exist electronic tuners, which enjoy finer precision for determining the frequency associated with a note. These tuners contain a microphone, which converts the acoustic signal into an electric signal, and a digital display device which indicates the closest note and also the accuracy of said note, according to the detected acoustic signal and the obtained electric signal.
Some tuners are calibrated on a fixed reference frequency, typically 440 Hz; others may, however, be adjusted on a neighbouring frequency to adapt the tone of the instrument to particular acoustic conditions, such as for example, the resonance properties of a building or concert hall.
One drawback of portable electronic chromatic tuners is that they are often relatively large and liable to be forgotten or lost by the musician. Moreover, the information provided on the digital display cannot be read intuitively, particularly with respect to the accuracy of the note and the adjustments, both during the calibrating operation and the actual tuning. There therefore exists a requirement for a chromatic tuner that overcomes the limitations of the prior art.
It is an object of the present invention to propose a chromatic tuner integrated in a portable instrument which is regularly available to musicians.
It is another object of the present invention to propose a chromatic tuner which allows easier reading and adjustment of frequencies obtained during tuning and of the calibration frequency.
These objects are achieved by the invention owing to a portable timepiece having the features of the independent device claim set out below.
These objects are also achieved by the invention via a chromatic tuner display method using the portable timepiece according to the invention.
One advantage of the proposed solution is that it allows a chromatic tuner to be integrated in a watch, which means that musicians who need a tuner do not require separate instruments, and this tool can be almost permanently on hand, as often as the watch containing the tool is worn.
Another advantage of the proposed solution is that it the tuning results can be read more easily owing to the hands of the watch in which the tuner is integrated.
Example implementations of the invention are given in the description and illustrated in the annexed Figures, in which:
a, 7b, 7c and 7d illustrate different variants for the display of the notes of the tempered scale.
The invention concerns a portable timepiece, typically a wristwatch, but for example also a pendant, a fob watch or any other portable time display device, with an integrated chromatic tuner which uses one or more hands of the watch, usually dedicated to the current time display. This timepiece consequently implicitly includes a tuning mode which is distinct from the usual time display mode, and in which at least one of the hands is no longer used for that purpose.
The tuner includes an electronic module for calculating the value of the acoustic frequencies transmitted by the instrument to be tuned, and this value and the accuracy of the frequency with respect to notes of a scale, for example the tempered scale (do, do#, re, re#, mi, fa, fa#, so, so#, la, la#, ti, for which the reference frequency is that from la at 440 Hz) is displayed on the timepiece. The English notation system for the tempered scale gives the note “la” the value A, “ti” the value B, “do” the value C, “re” the value D, “mi” the value E, “fa” the value F and “so” the value G, as will be seen hereinafter in the display devices according to preferred embodiments of the invention. Those skilled in the art will understand that it is possible to envisage adapting the integrated tuner according to the invention to any type of scale (natural, Pythagorean) and any tonic system.
The signal processing means 102 is formed of a filter 1021, which removes frequency components outside a defined signal bandwidth. Signal 10 is then transmitted to an amplifier 1022 and to a comparator 1023, such as, for example, a Schmitt trigger hysteresis comparator.
The pulse train 108 is transmitted to one of the input/output interfaces of a microcontroller 103, which is referenced 115 as a whole for the sake of simplification. Microcontroller 103 has at least one output for delivering a supply current 106 for signal processing means 102, a battery 107, a quartz oscillator 104, typically a 32 KHz oscillator wherein the frequency is temperature compensated, with periodic inhibitory correction. Microcontroller 103 also integrates an RC oscillator 105, preferably a 4 MHz oscillator, which allows the clock of processor 113 of microcontroller 103 to be switched to a faster frequency when long calculations or quick measurements have to be performed, mainly during activation of the tuning function.
As illustrated in
According to the preferred embodiment illustrated in
Timepiece 1 with the integrated chromatic tuner according to the invention encompasses totally analogue display systems or hybrid systems with partially digital displays. These embodiments are illustrated respectively in
According to this preferred embodiment, the RC oscillator 105 is first of all calibrated in a step 201, since the frequency thereof varies in time as a function of the supply voltage and temperature. The calibration consists in counting the number of clock pulses of the RC oscillator 105 within a time window set by the period of a signal derived from the temperature compensated base clock 104. The calibration is performed periodically, for example at 3 and 33 seconds, to ensure stability of the acoustic signal measuring frequency. The correction factor 25 results from the oscillator calibration to compensate for the set frequencies during the note identification process.
Step 202 consists in the microcontroller 103 (not shown in
Step 204 of identifying the fundamental period of electro-acoustic signal 10 is then determined by searching for a periodic relation between the elements of series 234. The process starts from the smallest element of the series then searches for multiples of this element going through the series in ascending order. Each element of the series is divided by ascending integer numbers until the smallest element is reached. As soon as one element of the series comes close to a multiple of this smallest element, then this element is deemed to be the fundamental signal period. If, however, no multiple is found then the process is repeated with the next element of the series until a periodic relation is found in the series. Step 2041 consists in checking whether a fundamental period has actually been found. If so, the result 24 is subjected to the correction factor 25 to give the measured period 26. If not, the threshold used in step 2031 is compared to half the value of the initial threshold, in step 2034, then decremented by a predefined value, for example 10, in step 2035 to determine the new threshold to be used in another repetition of the process of extracting fundamental frequency 203, which will thus repeat all of the preceding steps from 2031 with the new threshold. If the threshold is less than half the initial threshold after step 2034, the fundamental frequency identification process 203 ends at step 206 and no frequency has been identified. The fundamental frequency extraction process 203 has thus failed at step 206.
Once the identified signal period 24 has been delivered by process 203, and the correction has been performed by multiplying by correction factor 25 (illustrated in
Once the closest note 11 has been identified, the accuracy of the identified period relative to said note still has to be determined. This step 205 consists in determining the relative frequency deviation 12 between note 11 and received signal 10, which can preferably be calculated as follows:
If the acoustic signal frequency is lower than that of the closest note 11, the frequency deviation 12 is equal to the frequency of note 11, less the frequency corresponding to the measured period 26, i.e.
the inverse thereof (the frequency is, by definition, equal to the inverse of a period), and the whole divided by the frequency deviation between note 11 and the note immediately below, i.e. in the tempered scale one semitone lower. The whole is then multiplied by 100 to obtain a percentage. For the sake of simplification and legibility of the diagram of
The same reasoning applies when the acoustic signal frequency is higher than that of the closest note 11, in which case the frequency deviation 12 is measured as the difference between the acoustic signal frequency and the closest note, the whole divided by the difference between the frequency of the note immediately above, i.e. in the tempered scale one semitone higher, and the closest note 11.
With this note accuracy calculation for the tempered scale, those skilled in the art will observe that precision is indicated relative to a frequency deviation of one semitone, since the deviation between the different identifiable notes is always a semitone. It therefore extends from the quarter tone below to the quarter tone above. This precision is preferably indicated by a percentage comprised between −50 and +50%.
According to the embodiment illustrated in
The fact of using the larger hand 2 to determine the closest note 11 allows the result to be read quickly and intuitively, while hour hand 3 is used here to give the frequency deviation 12 between the note and the received electro-acoustic signal 10. The display device includes an indicator of the accuracy of the notes 7, formed here by graduations opposite which the hour hand 3 is positioned when the watch is in tuning mode. The indicator displays tone ranging from a quarter tone below to a quarter tone above the closest note 11, and also enables the accuracy to be read intuitively owing to the matching size of hour hand 3, which moves opposite the graduations, which are preferably spread out in the top half of the watch dial, from nine o'clock to three o'clock, to avoid superposing this information on information regarding the pitch of the note. The information regarding the pitch of the closest note 11 and the accuracy of the note are thus totally separate.
It will be noted that the accuracy indication using the hour hand is preferably arranged in the arc of a circle, the angular value of which is preferably slightly less than 180 degrees, preferably around 120 degrees, as illustrated in
In order to make it easier to read the accuracy of the note, the embodiment of
The embodiment of
According to a variant that is not shown, the additional data indicated by the digital display means 116 could be the pitch, i.e. the reference frequency used for the frequency measurement of the notes, when the latter can be adjusted on a frequency other than the usual A frequency of 440 Hz. Preferably this means is located in the bottom portion of dial 4 below hands 2 and 3 when said hands are used in tuning mode to indicate the accuracy of the closest note 11.
In a more basic variant for the display of intrinsic frequency 19 of signal 10, the two hour and minute hands 3 and 2 could be superposed during display of the detected frequency and both point to a value read on a scale of notes 6. However, this variant requires the user to appreciate the accuracy without using any other indicator 7.
An important difference between the variant of
The calibration value is displayed on a calibration value scale 15, arranged opposite one of hands 2 or 3, preferably minute hand 2, preferably on the bottom half of the dial, so as to leave space available for a note accuracy indicator 7, in a similar manner to the variants previously described.
Although the variant of
The variants illustrated in
Variant 7a adopts the same scale of notes 6 as that illustrated in
c concerns a hybrid display mode, which uses a digital display for the notes 11 closest to the acoustic signal. Bezel 5 can thus again include the numbers of the hours instead of the places of the notes in the variants of
d again concerns an analogue display embodiment, which differs from the embodiments of
Given the reduced angular space for indicating note accuracy compared to the other embodiments of the invention, specific shapes or specific colours could be used, for example green for the hands displaying the notes and the hand displaying accuracy, regardless of whether it is hour hand 3 or minute hand 2 (the function of each could be reversed), and superposing the hands so that the colour indicating accuracy, for example red, is hidden by the colour, for example green, indicating the note when the frequencies tally. As regards shape, a hollow hand could for example be favoured, preferably minute hand 2, which is larger than hour hand 3. Hour hand 3 is then housed in the hollow 71 in minute hand 2 when the frequencies tally. This variant has the advantage of not overloading dial 4 with accuracy data, thereby freeing place for other types of data. However it has the drawback of higher machining costs for the hollow hand, which is more difficult to make than a standard hand.
The variant of
More generally, the various embodiments described are given by way of example and should in no event be interpreted in a limiting manner. It is for example possible to envisage combining the features of the various embodiments described, or even to add others, known to those skilled in the art, without departing from the scope of the invention.
Number | Date | Country | Kind |
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09169640.1 | Sep 2009 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/062582 | 8/27/2010 | WO | 00 | 5/21/2012 |