JP3757641B2 - Tempo control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for changing the tempo (value) by detecting the movement of an object (for example, a hand) that a user moves.
[0002]
[Prior art]
At present, automatic performance apparatuses are widely used not only as dedicated apparatuses but also in musical sound generation apparatuses such as electronic musical instruments, synthesizers, and controllers. The automatic performance device is a device that performs performance (used in the sense including accompaniment) by processing performance data, and the performance is performed at a set tempo. The tempo control device is mounted on such an automatic performance device as a device for allowing the user to set an arbitrary tempo value.
[0003]
Many of the tempo control devices employ a method in which a user directly designates a tempo value by operating a switch or the like as a method for causing a user to designate a newly set tempo value. However, some tempo control devices employ a method in which a user specifies a tempo value by moving an object (for example, a hand). In this method, information specifying the tempo value is extracted from the movement of the object, so that it is hereinafter referred to as a tempo extraction method for convenience. The information specifying the tempo value is hereinafter referred to as tempo information for convenience.
[0004]
A tempo control apparatus that employs a tempo extraction method is provided with a light source such as an LED (light emitting diode) and a photosensor, for example, in order to detect the movement of an object moved by a user. The tempo control device uses them to extract tempo information as follows, for example.
[0005]
The photosensor is used to receive light emitted from a light source or light reflected from an object. By causing the photosensor to receive any of such light, it is determined whether or not the object is present at a position detected by the photosensor from the amount of received light.
[0006]
When the user is moving the object, the determination result of the presence / absence of the object based on the amount of light received by the photosensor is alternately changed from “Yes” to “No” and “No to Yes”. Focusing on this, a time interval at which the determination result changes, for example, a time interval (period) from when it is determined to be present until it is determined again to be present is measured, and the time interval measured is extracted as tempo information. The tempo value to be newly set is determined based on the tempo information extracted in this way.
[0007]
[Problems to be solved by the invention]
In a tempo control device that employs the tempo extraction method, the light source must be driven in order for the photosensor to receive the light emitted from the light source or the reflected light. The light source is normally intermittently driven in order to reduce power consumption and avoid the influence of ambient light such as an electric lamp.
[0008]
The conventional tempo control device performs the intermittent drive by driving the light source every time a predetermined time interval elapses, and samples (detects) the amount of light received by the photosensor at the timing of driving the light source. The tempo was changed based on the amount of light received. Therefore, there are the following problems depending on the time interval for driving the light source.
[0009]
When the time interval is set to be relatively long, the timing for detecting the movement of the object is delayed as a whole, and the accuracy of extracting tempo information decreases. For this reason, there is a problem that the tempo value desired by the user cannot be set with high accuracy.
[0010]
On the other hand, when the time interval is set to be relatively short, a slight movement such as a shake of an object is detected, and the tempo value is changed regardless of the user's intention.
[0011]
Thus, in any conventional tempo control device, it is difficult to change the tempo value as intended by the user. For this reason, it has been strongly desired to avoid these problems together.
[0012]
An object of the present invention is to provide a tempo control device capable of changing to a desired tempo value with high accuracy in accordance with a user's intention.
[0013]
[Means for Solving the Problems]
A tempo control device according to the present invention is mounted on an automatic performance device, and is based on the premise that the automatic performance device controls the value of a tempo at which automatic performance is performed. Tempo changing means for changing the tempo value based on the movement of the object detected by the detecting means, and control means for causing the movement detecting means to detect the object by changing the time interval at which the motion detecting means detects the object; Are provided.
[0014]
In the above configuration, it is desirable that the control means changes the time interval with a predetermined performance unit as a cycle. In addition, it is desirable that the control means lengthens the time interval of the period positioned at the beginning of the performance unit and the period positioned at the end compared to the time intervals of other periods. The performance unit is preferably a beat.
[0015]
In the present invention, a change is made in the time interval of the timing for detecting an object, and when an object is detected at that timing, the tempo value is changed based on that timing.
[0016]
By providing a change in the time interval, the accuracy with which an object is detected within a certain period is changed. For this reason, by adjusting the time interval according to the required accuracy, the change of the tempo value against the user's intention can be avoided, and the intended change of the tempo value can be performed with high accuracy.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a circuit configuration diagram of an automatic performance device equipped with a tempo control device according to the present embodiment.
[0018]
As shown in FIG. 1, the automatic performance apparatus includes a CPU 101 that controls the entire apparatus, a ROM 102 that stores programs, performance data (sequence data) for automatic performance, various control data, and the like. RAM 103, operator group 104 consisting of various operators, waveform memory 105 storing waveform data of various musical sounds, and reading out the waveform data from the waveform memory 105 in accordance with instructions from the CPU 101, and performing necessary processing thereon. A sound source LSI 106 to be output, a D / A converter 107 that D / A converts the waveform data output from the sound source LSI 106 and outputs an analog audio signal, an acoustic amplifier 108 that amplifies the audio signal, and an acoustic amplifier 108 Speaker 109 that inputs output audio signal and emits musical sound A light-emitting unit 111 having an LED 110 as a light source that emits light, a driver circuit 112 that performs current (or voltage) amplification of a signal (light-emitting signal) sent from the CPU 101, and outputs and amplifies it to the light-emitting unit 111; A light receiving unit 114 having a photosensor (photodiode) 113, and an A / D converter 115 for A / D converting the light reception signal output from the light receiving unit 114 and outputting the digital value thereof. ing.
[0019]
The operator group 104 includes various operators and a circuit that detects their operation state. The detection circuit detects the operation state of each operation element by scanning, for example, and sends the detection result to the CPU 101 as operation information for each operation element. Although not shown in the figure, the operation element is not particularly shown. A start / stop switch for instructing start or stop of automatic performance (including automatic accompaniment in this case), a plurality of numeric keys for designating a song to be automatically performed, and a tempo A tempo button for designating a value, a mode switch for selecting one of the modes prepared in advance, and the like are provided. The light emitting unit 111 (LED 110) and the light receiving unit 114 are driven during automatic performance when a predetermined mode is selected by the mode switch. The predetermined mode is hereinafter referred to as a tempo extraction mode for convenience.
[0020]
The photo sensor 113 is arranged in a line with the LED 110 of the light emitting unit 111. Thereby, the photosensor 113 receives light emitted from the LED 110 and reflected by the reflector 120. Thus, the user designates the tempo by moving the reflector 120 along the optical path of the light emitted from the LED 110 or in the crossing direction of the optical path (usually reciprocating movement). The reflector 120 is specifically a user's hand or a command stick.
[0021]
The operation of the above configuration will be described.
In particular, when the power is turned on by operating a power switch (not shown), the CPU 101 reads out and executes a program stored in the ROM 102 to start control of the entire apparatus. The control is performed in accordance with a user operation on the operator group 104 while using the RAM 103 for work.
[0022]
In order to detect a user operation performed on each operation element, the CPU 101 sends a control command to the detection circuit of the operation element group 104, causes the detection circuit to scan each operation element, and the scan result (each Operation information indicating the operation state of the operator) is received. By analyzing the scanning result (operation information), the operation element whose state has changed and the content of the change are determined. The above control is performed according to the function assigned to the operator and the contents of change.
[0023]
For example, when it is determined that the numeric key, the tempo button, or the mode switch is operated as a result of analyzing the scanning result, the CPU 101 determines the value of the variable stored in the RAM 103 according to the type of the operator that is determined to be operated. Rewrite. As a result, the music to be played automatically, the tempo value are changed, and the mode is switched. At this time, if the tempo value is changed, the value for automatic performance execution corresponding to the changed tempo value is substituted for the variable TEMPOVALUE referred to when the automatic performance is executed.
[0024]
On the other hand, if it is determined that the start / stop switch has been operated, the CPU 101 sets a value of a variable (hereinafter referred to as an automatic performance flag for convenience) for managing whether or not automatic performance is being performed, for example. rewrite. Thus, for example, if the previous value is 1, it is changed to 0, and if the previous value is 0, it is changed to 1. Based on the value of the automatic performance flag after such rewriting, it is determined whether or not automatic performance is currently being performed, and the following control is performed according to the determination result.
[0025]
Note that the performance data to be processed to perform the automatic performance is configured by adding time data indicating the timing at which the performance data is to be processed to event data indicating the content of the event on performance, for example.
[0026]
If it is determined that the automatic performance is not currently being performed, the CPU 101 refers to the variable stored in the RAM 103 and reads the performance data of the music designated by the user from the ROM 102. Thereafter, for example, the event data in the performance data read from the ROM 102 is sent as a control command to the tone generator LSI 106 in accordance with the time data added thereto, thereby executing the automatic performance.
[0027]
The tone generator LSI 106 performs processing such as output of waveform data, change of timbre, or addition of an acoustic effect according to the contents instructed by the control command. For example, if the control command has a content for instructing the pronunciation of a musical tone, the waveform data of the tone color of the musical tone instructed to be reproduced is read from the waveform memory 105 and subjected to a necessary operation, and then D / A conversion is performed. Output to the unit 107. The D / A converter 107 converts the waveform data input from the sound source LSI 106 into an analog audio signal, and the acoustic amplifier 108 amplifies the audio signal and outputs the amplified audio signal to the speaker 109. It will be.
[0028]
On the other hand, if it is determined that the automatic performance is currently being performed, the CPU 101 stops the automatic performance by stopping the processing of the performance data. For example, a control command for instructing mute of all the musical tones being generated is sent to the tone generator LSI 106 to stop the musical sound from being produced from the speaker 109.
[0029]
The automatic performance is basically performed at the tempo value designated by the user via the tempo button. However, when the user instructs execution of automatic performance with the tempo extraction mode selected, that is, when the start / stop switch is operated, the CPU 101 changes the tempo value as follows. A method for changing the tempo value will be described with reference to FIGS.
[0030]
FIG. 2 is a diagram illustrating the drive timing of the light emitting unit 111 (LED 110) and the light receiving unit 114 (photo sensor 113).
In FIG. 2, the light emission timing coincides with the timing at which the CPU 101 outputs a light emission signal to the driver circuit 112, and the effective light reception timing is obtained when the A / D converter 115 samples the signal output of the photosensor 113 of the light receiving unit 114. The timing at which the CPU 101 validates the change of the tempo value. Each line shown in FIG. 2 represents one timing. In the effective light reception timing, the timing that coincides with the beginning of the beat is indicated by a bold line.
[0031]
In the present embodiment, the light emitting unit 111 (LED 110) is driven short and at constant time intervals. Specifically, it is driven 48 times per beat. While the light emitting unit 111 (LED 110) is driven (emitted) in this way, the output of the A / D converter 115 is basically effective in accordance with the light emission timing of the light emitting unit 111 as shown in FIG. However, the effective timing interval is changed with the beat as the period of change. Specifically, the timing is effective at a larger interval in the vicinity of the head of the beat than in other portions. Accordingly, for example, in the vicinity of the head of the second beat, when expressed by the number of times of driving of the light emitting unit 111 with reference to the head of the bar, the timing at which the light emitting unit 111 is driven at the 43rd, 45th to 47th, 49th to 51st and 53rd times. Then, the output of the A / D converter 115 is not validated. Note that the timing at which the output of the A / D converter 115 is validated will be expressed by the number of times the light emitting unit 111 is driven based on the head of the measure.
[0032]
The CPU 101 acquires tempo information for changing the tempo value by measuring the time interval from when the reflective object 120 moved by the user is detected by the photo sensor 113 until it is detected again. The time interval is measured in consideration of the effective light reception timing. As a result, when the photo sensor 113 detects the reflecting object 120 at a timing that is not valid, the tempo information is extracted based on the assumption that the reflecting object 120 is detected at a timing near the timing. The tempo information obtained in this way changes the tempo value assuming that the time interval is one beat newly designated by the user.
[0033]
The tempo value changed as described above is immediately reflected in the automatic performance. In that case, if the change timing of the tempo and the movement of the reflector 120 are not linked (synchronized), an unnatural impression is given to the user. In order to avoid this, the progress of performance in units of beats is performed in accordance with the detection of the reflector 120.
[0034]
FIG. 3 is a diagram for explaining the detection timing of the reflector 120. For example, when the user moves his / her hand as the reflector 120, the timing for detecting the hand in correspondence with the effective light reception timing is shown. For comparison, the light receiving timing and the hand of the conventional example with a short time interval of light reception timing (hereinafter referred to as the first conventional example) and the conventional example with a long time interval (hereinafter referred to as the second conventional example). The detection timing is also shown. With reference to this FIG. 3, the timing which detects the reflector 120 (here hand), and its difference with the past are demonstrated concretely.
[0035]
In FIG. 3, (a) is the light reception timing of the first conventional example, (b) is the light reception timing of the second conventional example, (c) is the effective light reception timing of this embodiment, and (d) is the reflection. (E) is a detection timing in the first conventional example, (f) is a detection timing in the second conventional example, and (g) is a detection timing in the present embodiment. . Similar to FIG. 2, the lines shown in FIGS. 3A to 3C represent the light reception timing, and the thick line represents the timing coincident with the beginning of the beat in the light reception timing. The timing of the beginning of the beat changes according to the timing of detecting the hand, but here, for convenience, the light reception timing is shown ignoring this. The numbers 1 to 4 indicate the number of beats positioned from the beginning of the measure.
[0036]
As shown in FIG. 3, when the user moves his / her hand to a position where the hand can be detected at a timing coincident with the head of the beat (hereinafter referred to as a detectable position), the first and second conventional examples and the present embodiment Both detect the hand at that timing. However, if the timing of moving the hand to the detectable position is slightly delayed, the first conventional example with a short time interval of the light receiving timing detects the hand at that timing. In contrast, in the second conventional example and the present embodiment, the hand is detected at the timing of the head of the beat (which is the third beat). The time interval from detection of a hand to detection of a hand again (hereinafter referred to as a beat interval) is time a in the first conventional example, whereas in the second conventional example and this embodiment, the time interval is a. Time b is reached.
[0037]
As long as the human moves the hand (reflecting object 120), there is inevitably some deviation. The deviation occurs even if the user does not intend to change the tempo value. This means that even if there is a change in the hand movement that slightly changes the tempo value until then, the user rarely changes the movement of the hand with the intention of changing the tempo. . In the first conventional example, the deviation is detected and treated as a change in tempo information, so it is very difficult to maintain a constant tempo. On the other hand, in the present embodiment, since such a shift is ignored as a result, a tempo change unintended by the user can be avoided and a constant tempo can be easily maintained.
[0038]
On the other hand, when the user moves the hand to a detectable position at a timing that is not in the vicinity of the head of the beat, the second conventional example and the present embodiment detect the hand at that timing, whereas the second In the conventional example, the hand is detected with a delay from the timing.
[0039]
The fact that the hand is detected at a timing that is not in the vicinity of the head of the beat means that the user has changed the time interval from moving the hand that was at the detectable position to the detectable position again relatively large. means. Therefore, it can be said that there is a high possibility that the user has made a change in the movement of the hand with the intention of changing the tempo. In the second conventional example, basically, the hand movement cannot be detected with high accuracy, and therefore the tempo value desired by the user cannot be set. On the other hand, in the present embodiment, such a hand movement is detected in a period in which the time interval of the effective light reception timing is short, so that a change in the hand movement can be detected with high accuracy. Thereby, the tempo value desired by the user can be set with high accuracy.
[0040]
As described above, when the user moves the hand to a detectable position at a timing near the head of the beat, the timing for detecting the hand in the first conventional example, the second conventional example, and the present embodiment is as follows. Different. For this reason, when a relatively large change in hand movement occurs, the beat intervals are all different between the first and second conventional examples and the present embodiment. The time is c in the first conventional example, d in the second conventional example, and e in the present embodiment. From this, it can be seen that the first and second conventional examples cannot be changed to a desired tempo value with high accuracy according to the user's intention as in the present embodiment.
[0041]
Next, the operation of the CPU 101 described above will be described in detail with reference to various operation flowcharts shown in FIGS. 4, 5, and 7 and an explanatory diagram shown in FIG.
FIG. 4 is an operation flowchart of timer interrupt processing executed when the user operates the start / stop switch to instruct execution of automatic performance. With reference to FIG. 4, the process will be described in detail first.
[0042]
The timer interrupt process is a process executed at predetermined time intervals by an interrupt signal output from a hard timer built in the CPU 101, for example. When the interrupt signal is output, the CPU 101 reads out a program corresponding to the interrupt signal from the ROM 102 and transfers control to it to execute a timer interrupt process. For convenience, the timer interrupt process will be described here on the assumption that the tempo extraction mode is selected. The number of beats in one measure is 4.
[0043]
As described above, in the present embodiment, the LED 110 of the light emitting unit 111 is caused to emit light at a time interval of 1/48 beats. The time interval changes according to the tempo value. The timer interrupt process is executed at predetermined time intervals. For this reason, the variable TEMPOVALUE is substituted with a value corresponding to the tempo value with the execution interval of the timer interrupt process as a unit.
[0044]
First, in step 401, it is determined whether or not the value of the variable TEMPOVALUE is equal to the value of the variable SKY. If the values of these variables are equal, the determination is yes and the process moves to step 402. Otherwise, the determination is no and the process moves to step 409.
[0045]
The variable SKY is a variable prepared for counting the number of times of execution of the timer interrupt process in order to specify a time interval of 1/48 beats. In step 402, 0 is substituted for the variable SKY. By substituting 0 for the variable SKY in this way, in step 401, YES is determined for each time interval corresponding to 1/48 beats.
[0046]
In step 403 following step 402, the value of the variable X prepared to advance the automatic performance in units of measures is incremented. After that is completed, the process proceeds to step 404. The variable X is referred to in order to determine the effective light reception timing, as will be described later.
[0047]
In step 404, it is determined whether or not the value of the variable X is equal to 192 (= 48 × 4). Since the count number of the variable X is 48 per beat, it becomes 192 when the beat number of one measure is four. For this reason, when counting for one measure is performed, the determination is YES, the process proceeds to step 405, and 0 is substituted for the variable X, and then the process proceeds to step 406. Otherwise, the determination is no and the process moves to step 406.
[0048]
In step 406, automatic performance processing is performed for performing automatic performance by processing event data in accordance with time data. In the subsequent step 407, a light emission process for causing the LED 110 of the light emitting unit 111 to emit light is executed. After that is completed, the process proceeds to step 408.
[0049]
The event data is processed by, for example, the CPU 101 sending it to the sound source LSI 106. The light emission process is performed by the CPU 101 sending a light emission signal to the driver circuit 112.
[0050]
In step 408, a value (light reception value) indicating the amount of light received by the photosensor 113 of the light receiving unit 114 is input from the A / D converter 115, and light reception processing for extracting tempo information and further changing the tempo value is executed. To do. Thereafter, the series of processing is terminated.
[0051]
On the other hand, when the determination in step 401 is NO, that is, when the value of the variable SKY is different from the value of the variable TEMPOVALUE, the value of the variable SKY is incremented in step 409. After the increment, the process proceeds to step 408.
[0052]
As described above, in the timer interrupt process, the automatic performance process in step 406 and the light emission process in step 407 are executed for each time interval corresponding to 1/48 beats. Therefore, the automatic performance is performed at the set tempo value, and the LED 110 emits light at a time interval of 1/48 beats.
[0053]
FIG. 5 is an operation flowchart of the light receiving process executed as step 408, and FIG. 6 is a diagram for explaining a method for extracting tempo information. Next, the light receiving process will be described in detail with reference to FIGS. 5 and 6.
[0054]
First, extraction of tempo information performed in the light receiving process will be described with reference to FIG.
In FIG. 6, the vertical axis represents the output value of the A / D converter 115, the horizontal axis represents time, and the graph shows the time change of the output value of the A / D converter 115. A and B shown on the vertical axis are predetermined threshold values. Specifically, the threshold A is a threshold determined to determine whether or not the photosensor 113 has detected the reflecting object 120, and the threshold B is detected by the photosensor 113 as the reflecting object 120 moves. This is a threshold value that is set to determine whether or not it has disappeared.
[0055]
The tempo information is basically obtained by measuring the time interval from when the reflector 120 is detected until it is detected again. In this embodiment, a variable ONFLAG is prepared in order to measure the time interval. The variable ONFLAG is set when the output value of the A / D converter 115 becomes larger than the threshold A, that is, 1 is substituted, and when the output value becomes smaller than the threshold B, it is reset, that is, 0 is substituted.
[0056]
The reason why the variable ONFLAG is reset at the timing described above is to allow the variable ONFLAG to be set when the output value of the A / D converter 115 becomes larger than the threshold value A next time. In this embodiment, the variable ONFLAG is set or reset in such a manner, so that the tempo information is acquired by measuring the period from setting the variable ONFLAG to the next setting.
[0057]
Turning to the description of the light receiving process shown in FIG.
First, in step 501, the output value of the A / D converter 115 is fetched and substituted into the variable Y. In the subsequent step 502, it is determined whether or not the value of the variable Y is larger than the threshold value A. If the value of the variable Y is larger than the threshold A, that is, if the reflector 120 moves to a detectable position and the photo sensor 113 detects it, the determination is YES and the process proceeds to step 503. . Otherwise, the determination is no and the process moves to step 507.
[0058]
In step 503, it is determined whether the value of the variable ONFLAG is 1. If 1 is assigned to the variable ONFLAG, the determination is YES and the process proceeds to step 509. Otherwise, the determination is NO and the process proceeds to step 504.
[0059]
In step 504, 1 is substituted into the variable ONFLAG. Setting the variable ONFLAG means that tempo information has been acquired as the reflector 120 is detected. For this reason, in the subsequent step 505, a thinning process for changing the tempo value based on the acquired tempo information and the effective light reception timing is executed. When this is completed, the process proceeds to step 506, where 0 is substituted into a variable COUNTER prepared for acquiring tempo information, that is, for measuring the detection interval of the reflecting object 120, and then a series of processing ends.
[0060]
On the other hand, if the determination in step 502 is NO, that is, if it is determined that the output value of the A / D converter 115 is equal to or less than the threshold value A, it is determined whether or not the output value is smaller than the threshold value B. If the amount of light received by the photosensor 113 decreases or is small due to the reflection object 120 moving away from the detectable position, the output value of the A / D converter 115 becomes smaller than the threshold value B, so that determination is YES and step 508 Then, the process proceeds to step 509 after resetting the variable ONFLAG. Otherwise, the determination is no and the process moves to step 509.
[0061]
In step 509, the value of the variable COUNTER is incremented. After the increment, a series of processing is terminated.
In the light receiving process, the value of the variable COUNTER is incremented every time the process is executed, except when the output value of the A / D converter 115 is larger than the threshold value A and the variable ONFLAG is set. As a result, the variable COUNTER is assigned a value representing the period from when the variable ONFLAG is set to when it is set again, with the execution interval of the light receiving process, that is, the execution interval of the timer interrupt process shown in FIG. It will be.
[0062]
FIG. 7 is an operation flowchart of the thinning process executed as step 505. Next, the thinning process will be described in detail with reference to FIG.
In the present embodiment, as described above, the time interval of the effective light reception timing is relatively large in the vicinity of the head of the beat, and when the reflector 120 is detected in the meantime, the detected timing is ignored, The tempo value is changed as detected at the effective light reception timing (here, the timing of the beginning of the beat) in the vicinity thereof. It is determined with reference to the value of the variable X whether or not the timing at which the reflector 120 is detected is the effective light reception timing. For this reason, the thinning-out process changes the tempo value according to the value of the variable X.
[0063]
First, in step 701, it is determined whether the value of the variable X is 0 or more and less than 6. If the value of the variable X is a value in the meantime, the determination is YES and the process proceeds to step 702. Otherwise, the determination is NO and the process proceeds to step 703.
[0064]
In step 702, it is determined whether or not the value of the variable X is 0 or 4, that is, whether or not the value of the variable X represents an effective light reception timing. When the photosensor 113 detects the reflecting object 120 at the effective light reception timing, that is, when the output value of the A / D converter 115 becomes larger than the threshold value A, the determination is YES, and the process proceeds to step 711, otherwise. In that case, the determination is NO, and the series of processing ends.
[0065]
In steps 703 to 710, in the same manner as described above, it is determined whether or not the photosensor 113 has detected the reflecting object 120 at the effective light receiving timing, and it is determined that the photosensor 113 has detected the reflecting object at the effective light receiving timing. In step S711, the process proceeds to step 711. If not, the series of processing ends without changing the tempo value, that is, the value of the variable TEMPOVALUE.
[0066]
In step 711, a value obtained by dividing the value of the variable COUNTER by 48 is substituted for the variable TEMPOVALUE. Thereby, the tempo value is changed. Thereafter, the series of processing is terminated.
[0067]
FIG. 8 is a diagram for explaining an example of changing the tempo. The change in the tempo value performed as described above shows how the beat time interval changes according to the timing at which the reflector 120 is detected in terms of effective light reception timing. “With light reception” in the figure indicates the timing at which the reflector 120 is detected, that is, the timing at which the output value of the A / D converter 115 becomes greater than the threshold value A. Numerical values 1 to 4 indicate the number of beats positioned from the beginning of the measure.
[0068]
As shown in FIG. 8, when the reflector 120 is detected before the timing of the head of the second beat, after the timing when the reflector 120 is detected, the tempo is set so that the time f becomes a performance period of one beat. Is changed. When the remaining time of 1 beat reaches the time elapsed at the changed tempo, the performance shifts to the 2nd beat, but since the reflector 120 is detected at the beginning of the 3rd beat, the tempo value based on the detection is detected. Changes are avoided. Thereby, the performance period of the second beat is time f.
[0069]
In the present embodiment, it is assumed that the change of the tempo value is faster, but the tempo value may be changed only on the assumption of the slower one. Of course, the tempo value may be changed to either of them.
[0070]
Further, in this embodiment, as shown in FIG. 8, only the tempo value is changed at the timing when the reflecting object 120 is detected. However, when changing the tempo value, as shown in FIG. If necessary, the automatic performance may be advanced in units of beats.
[0071]
As shown in FIG. 2, the effective light reception timing is rough in the vicinity of the beginning of the beat in the present embodiment and dense in the other portions. However, in order to enable subtle changes in the tempo value, Also good. That is, it may be dense in the vicinity of the beginning of the beat and rough in other areas. In the present embodiment, the effective light reception timing is determined from the data in the program. However, some patterns of effective light reception timing are prepared in the ROM 102 as control data, and the pattern desired by the user is prepared from them. May be selected. In order to support a device using a battery or the like as a power source, a plurality of patterns having different timing intervals as a whole may be prepared, and a pattern may be automatically selected according to the voltage of the power source.
[0072]
In this embodiment, the LED 110 and the photosensor 113 are driven (reading the output value of the A / D converter 115) even at a timing that is not the effective light reception timing. However, they are driven only at the effective light reception timing. May be. In any case, the tempo value may be changed only when the reflecting object 120 is detected at the effective light reception timing.
[0073]
Although the tempo control device according to the present embodiment is mounted on an automatic performance device, the device that can be mounted is not limited to the automatic performance device. It can be installed in a wide range of electronic musical instruments, controllers, synthesizers, etc. The tempo control device that already has a function of detecting the reflecting object 120 can basically be applied to the present invention simply by installing a program that realizes the operation described above.
[0074]
【The invention's effect】
As described above, according to the present invention, a change is made to the time interval of the timing for detecting an object, and when an object is detected at that timing, the tempo value is changed based on that timing. For this reason, while changing the tempo value against the user's intention, the intended tempo value can be changed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of an automatic performance device equipped with a tempo control device according to the present embodiment.
FIG. 2 is a diagram illustrating driving timings of a light emitting unit and a light receiving unit.
FIG. 3 is a diagram for explaining detection timing of a reflecting object.
FIG. 4 is an operation flowchart of a timer interrupt process.
FIG. 5 is an operation flowchart of light reception processing.
FIG. 6 is a diagram for explaining a method of extracting tempo information.
FIG. 7 is an operation flowchart of a thinning process.
FIG. 8 is a diagram illustrating an example of changing the tempo.
FIG. 9 is a diagram illustrating a tempo changing method according to another embodiment.
[Explanation of symbols]
101 CPU
102 ROM
103 RAM
104 Operator group
105 Waveform memory
106 Sound source LSI
110 LED
111 Light emitter
112 Driver circuit
113 Photosensor
114 Light receiver
115 A / D converter
120 Reflector

Claims (4)

A device that is mounted on an automatic performance device and controls the value of the tempo at which the automatic performance device performs automatic performance,
A motion detection means for detecting the motion of the object moved by the user;
Tempo changing means for changing the value of the tempo based on the movement of the object detected by the movement detecting means;
Control means for causing the motion detection means to detect an object by changing a time interval at which the motion detection means detects the object;
A tempo control device comprising: The control means changes the time interval with a predetermined performance unit as a cycle.
The tempo control device according to claim 1. The control means makes the time interval of the period located at the beginning of the performance unit and the period located at the end longer than the time intervals of other periods,
The tempo control device according to claim 1. The performance unit is a beat.
The tempo control device according to claim 1, 2, or 3.

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