JPH04170590A - Play condition detecting device for keyed instrument - Google Patents

Abstract

PURPOSE:To obtain a play condition detecting device for a keyed instrument facilitating mounting and adjustment as a whole by providing a detecting means having an extreme value to output a changing signal and an output value calculating means for calculating the first/second output values, output before and after this extreme value, based on this extreme value. CONSTITUTION:A detecting means 11, which is provided with an extreme value to output a changing signal corresponding to a change of distance from a constitutional member 36 while arranged approximately opposed to the constitutional member 36 of a chord tapping mechanism in a keyed instrument turned by key pressing operation, and an output value calculating means, which calculates the first/second output values output before and after this extreme value based on this extreme value, are provided. That is, a distance between two measuring points is calculated based on an output signal (first/second output values) from the detecting means 11. Time for the chord tapping mechanism constitutional member 36 to pass through these two measuring points is detected to calculate a chord tapping speed from measured values of these distance and time. In this way, mounting and adjustment are facilitated as a whole.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a performance state detection device for a keyboard instrument, and outputs a signal that has an extreme value and changes in response to a change in distance to a measured object, for example. A reflective optical sensor is used, and the optical sensor is placed at a position where the extreme value is output before the hammer string is struck, and the second output value after the extreme value is output from the time when the first output value is output before the extreme value is output. of two predetermined output signals by calculating the string-striking speed based on the elapsed time until the output of By calculating the string-striking speed based on the time difference between detection times, the sensor can be easily installed, adjusted, etc., and the string-striking speed of the hammer in a player piano can be accurately detected.

<Prior Art> A player piano can record its performance and automatically reproduce it. The record of this performance is
Specifically, a sensor detects and records the pressed key and the string-striking speed of the hammer corresponding to the key.

By detecting this string-striking speed, the tone color and volume are determined.

As a conventional device for detecting the string-striking speed of a player piano, a device having a configuration as shown in FIG. 9, for example, has been known.

In this detection device, as shown in FIG. 9, a hammer shutter 94 made of a plate material is attached to the middle part of a hammer shank 93 of a hammer 92 that strikes a string 91.

The transmitted light type optical sensors 95A and 95B are arranged by having a light projector and a light receiver facing each other on both sides of a plane including the rotation locus of the hammer shutter 94.

These optical sensors 95A.

95B are arranged close to each other. For example, these two optical sensors 95A and 95B are fixed to a fixed member 96 at a predetermined distance apart along the rotation locus of the hammer shutter 94.

That is, in the string-striking operation of the hammer 92, the hammer shutter 94 is configured to be able to block each optical path of these optical sensors 95A and 95B.

Therefore, the hammer shutter 94, which rotates together with the hammer 920 string-striking operation, sequentially blocks each optical path of the two transmitted light type optical sensors 95A and 95B. In this device, the time difference between the light-blocking times of these optical sensors 95A and 95B was measured, and based on this time difference, the string-striking speed of the hammer 910 was calculated and recorded.

Therefore, in order to accurately detect the actual string-striking speed by the hammer 92, rather than the rotational speed of the hammer shank 93 during the string-striking stroke, these optical sensors 95A, 95 are required.
It was necessary to mount B as close as possible to the position where the hammer 92 strikes the string.

In addition, in order to improve the detection accuracy, each optical sensor 95
A, positioning of the emitter and receiver in 95B,
Mechanical positioning between each optical sensor 95A, 95B and hammer shutter 94, and furthermore, each optical sensor 95A, 9
It was necessary to accurately set the interval between 5B.

<Problems to be Solved by the Invention> However, in such a conventional string-striking speed detection device for a player piano, the distance between all of the paired optical sensors 95A and 95B corresponding to 88ff is It was difficult to attach it at a certain distance. If there are variations in the installation distance, it will not be possible to obtain an accurate string-striking speed even if you measure the time difference.

Further, regarding the correction of the distance between the sensors and the sensor mounting position due to individual differences in hammers, it is difficult to fix the hammer shutter to the hammer shank, position the hammer shutter with respect to the sensor, etc. For example, in order to attach a hammer shutter to a hammer shank, the hammer shank must be processed with high precision, resulting in an increase in the number of assembly and adjustment man-hours.

Further, in such a conventional detection device, an optical sensor cannot be disposed close to the string-striking point. This is because mounting space for sensor positioning adjustment cannot be secured.

As a result, the conventional device only detects the average speed of rotation of the hammer, and cannot accurately detect the actual string-striking speed. This is because the actual string-striking point varies depending on the string-striking mechanism for each string, and conventional sensors cannot be mounted close to the string-striking point.

In other words, although sensors are required to perform highly accurate positioning, the accuracy of the detected string-striking speed may be low due to individual differences between each sensor, and there is still room for improvement. .

In other words, when a string is struck with a hammer, microscopically,
This is because the string digs into the hammer felt due to the impact, or the string bends due to the force of the string, making it extremely difficult to mechanically specify the exact location where the string is struck.

Therefore, it is recommended to use a sensor (e.g., a reflective optical sensor) that can follow the rotation of the string-striking mechanism such as a hammer, that is, that produces an output that corresponds to the change in distance between it and the string-striking mechanism component. is possible.

This optical sensor is configured to output a signal whose output value changes in response to a change in distance from the string-striking mechanism component. Then, in the sensor output, the first output value and the second output values are obtained, and the rotation time of the component between the two measurement points is measured based on these output values. Then, based on the distance and time between these two measurement points, the speed at which the string is struck by the hammer is obtained.

However, in this optical sensor, it is conceivable that variations occur in the output characteristics of each optical sensor with respect to changes in distance. This is because the output characteristics of each optical sensor are different, the reflectance of the light reflecting surface of the component is different, and there are individual differences in the mounting position of the optical sensor. Each sensor has different output characteristics. This causes variations in the calculation results of the string-striking speed for each sensor.

Therefore, it is necessary to correct the variation in string-striking speed detection by each optical sensor.

Therefore, an object of the present invention is to eliminate the work of attaching a hammer shutter to a hammer shank, eliminate the need for complicated work such as adjustment work when correcting individual differences in hammers, etc., and make the installation and adjustment easier as a whole. An object of the present invention is to provide a performance state detection device for a keyboard instrument.

Another object of the present invention is to provide a performance state detection device for a keyboard instrument that is capable of detecting the speed immediately before a string is struck and has improved accuracy in detecting the string striking speed.

Furthermore, another object of the present invention is that by normalizing the output of each sensor, e.g. by performing detection at a constant ratio to the peak output of the sensor (each peak value is different), all sensors , can be measured in a fixed measurement interval (fixed distance), and the detected output value (
An object of the present invention is to provide a performance state detection device for a keyboard instrument that eliminates variations in measurement time (→string-striking speed).

Another object of the present invention is to provide a performance state detection device that can easily change the measurement interval (increase the degree of freedom in setting the measurement interval) and can measure the speed at which the string is struck. .

<Means for Solving the Problem> The invention described in claim (1) is arranged in close proximity to and opposite to a component of a string-striking mechanism of a keyboard instrument that rotates when a key is pressed, and that the component is a detection means that outputs a signal that changes with an extreme value in response to a change in the distance between the The first output will be sent to
output value calculation means for calculating an output value and a second output value based on the extreme value; and output value calculation means for calculating an output value and a second output value based on the extreme value;
a timer for measuring the time taken to change from an output value to a second output value, and a string-striking speed calculation means for calculating a string-striking speed by the string-striking mechanism based on the measured time and the distance between the two measurement points. This is a performance state detection device for a keyboard instrument, comprising:

Furthermore, the invention described in claim (2) is arranged in close opposition to a component of a string-striking mechanism of a keyboard instrument that rotates when a key is pressed, and the distance between the component and the component changes. detection means that outputs a signal that monotonically changes in response to the
output value calculation means for calculating a first output value and a second output value based on a reference value of the output signal from the detection means; a distance setting means for setting a measurement point distance with respect to the reference value; A timing means for measuring the time during which the output from the means changes from the first output value to the second output value, and calculating the string-striking speed by the string-striking mechanism based on the measured time and the distance of the measurement point. This is a performance state detection device for a keyboard instrument, comprising: a string-striking speed calculation means for calculating a string-striking speed;

<Operation> The invention described in claim (1) and the invention described in claim (2) both detect two Calculate the distance between two measurement points. Then, the time taken for the string-striking mechanism component to pass through these two measurement points is detected, and the string-striking speed is calculated from the measured values of these distances and times. In this case, the first output value and the second output value output from the detection means are normalized with respect to the extreme value or reference value of the output signal. As a result, variations due to differences in the position of the detection device for each string do not occur. All calculated string-striking speeds are accurate.

For example, when a key is pressed, the string-striking mechanism rotates to strike a string, and the output of the detection means changes in response to the rotation of the string-striking mechanism. In the invention described in claim (1), the output value calculation means detects a peak value (extreme value) of the output, and calculates the first output value and the second output value based on this peak value. This standardizes measurement points in measurements based on the output of each sensor.

Then, when the string-striking mechanism is rotated by pressing the key again, the timer measures the elapsed time based on these first output values and second output values. For example, when a first output value is detected, a timer is started, and when a second output value is detected after the peak value has passed, the timer is stopped. The string-striking speed calculation means calculates the string-striking speed based on this elapsed time and the distance between the two measurement points.

Moreover, in the invention described in claim (2), the output of the detection means monotonically increases or decreases. Therefore, the first output value and the second output value are determined (normalized, standardized) based on, for example, the rate of increase in proportion to a reference value corresponding to a predefined measurement distance. Then, the distance between the two measurement points is calculated based on these output values, and when the first output value is detected by the rotation of the string-striking mechanism components, the timer is started and stopped when the second output value is detected. It is something. The string-striking speed calculation means calculates the string-striking speed from this elapsed time and the distance between the two measurement points.

<Examples> Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block circuit diagram showing a performance state detection device (string-striking speed detection device) for a player piano according to a first embodiment of the present invention.

FIG. 2 is a side view showing the string-striking mechanism of the player piano.

First, as shown in Fig. 1, this keystroke speed detection device is
It has a reflective optical sensor 11. The optical sensor 11 irradiates light onto members (described later) constituting the string-striking mechanism and outputs a current IC that changes depending on the intensity of the reflected light. The optical sensor 11 is set so that the output current Ic has a peak value IcMax during the string-striking stroke.

For example, the distance to the component and the focal length of the light receiving lens of the optical sensor 11 are set.

The output of the optical sensor 11 is the peak value IcM of the output current Ic.
It is input to an IcMax detection and holding circuit 12 that detects and holds ax.

The peak value ■cMax which is the output of this detection holding circuit 12
is processed in the arithmetic circuit 13, and the first output value is 0, 8IcMax, and the second output value is 0, 9IcM.
ax is calculated respectively.

The first output value (0,8I cMa

Further, the output Tc from the optical sensor 11 is output from the comparison circuit 18.
．． 19 respectively. These comparison circuits 1
8.19 are the above first output values (0,8IcM
ax) and the second output value (0°9I (Max)) and the output IC from this optical sensor 11 are compared.

The determination circuit 20 determines the comparison result of the comparison circuit 18, and starts the timer 21 when the output -Ic of the optical sensor 11 reaches the peak value IcMax and exceeds the first output value (0.81cMaX). Outputs a trigger signal.

Further, the determination circuit 22 determines that when the output of the optical sensor 11 changes,
As a result of the comparison in the comparator circuit 19, when the output IC exceeds the peak value IcMax and becomes smaller than the second output value 0°9IcMax, a stop signal is output to stop the timer 21.

The timer 21 measures the time from start to stop by the number of pulses, and outputs a timer signal Δt representing the elapsed time.
Output. This timer signal Δt is converted into a velocity of a MIDI signal by the MIDI velocity table 23 to obtain the string-striking intensity V by the string-striking mechanism.

Here, as shown in FIG. 2, an action (string-striking mechanism) 25 for striking the strings 24 stretched in the vertical direction is arranged corresponding to 88 keys.

The action 25 is composed of the following members.

That is, a hammer 26 that strikes the string 24, a hammer shank 27 connected to the hammer 26, a butt 28 fixed to the base end of the hammer shank 27, and a hammer shank 27 and the butt 28 that are connected to the center. It has a butt flange 29 that swingably supports a pin as a fulcrum, and a hammer rail 30 that defines the distance of the hammer shank 27 from the string 24.

The damper 31 is connected to the string 24 between the string 24 and the action 25.
is located close to. The damper 31 is linked to the action 25, but by stepping on the damper pedal, it is separated from the string 24 and the vibration of the string 24 can be sustained.

Here, 32 is a center rail that fixes and supports the bat flexure 29 and the like.

A horizontal bracket 33 is provided at the upper end of the center rail 32 and extends in a direction away from the strings 24. A rear end 33 of the bracket 33 spaced from the string 24
A is bent upward, and its bent side 3
A substrate 34 is horizontally fixed to the upper end of 3A. - This board 34 is provided with the above-mentioned circuits 12 to 23 and a reflective optical sensor 35 (above 11), and this reflective optical sensor 35 has a light projecting section 35A that can emit light downward.
and a light-receiving section 35B that can receive the reflected light.

The optical sensor 35 is arranged so as to be able to face a catcher 36 protruding from the rear side of the bat 28. That is, when a string is struck by the hammer 26, the end surface 36A of the catcher 36 rotates from the position shown by the broken line in FIG. 2 to the position shown by the solid line, and faces the optical sensor 35 with a predetermined distance therebetween. It is something. This catcher 36
is one of the constituent members of the string-striking mechanism 25, and therefore the optical sensor 35 is disposed close to and opposite to the constituent members of the string-striking mechanism 25.

In the figure, 37 is a jack and 38 is a wippen.

The optical sensor 35 emits light downward from a light projecting section 35A having a light emitting element (LED etc.), a light emitting lens, etc.
The reflected light that is reflected on one reflective surface is collected by a light receiving section 35B consisting of a light receiving element (photodiode, etc.), a light receiving lens, etc.
The light is received at The optical sensor 35 receives light 1M3.
Reflected light received by 35B! :(Intensity) according to its output current machining. changes.

Further, in the string-striking stroke by the action 25, the catcher 36 rotates together with the bat 28, the hammer 26, etc., and the distance Hd between the end surface 36A of the catcher 36 and the optical sensor 35 changes. Corresponding to this distance change, the amount of reflected light received by the light receiving section 35B of the optical sensor 35 changes.

Here, the output Ic of the optical sensor 35 with respect to the change in the distance d changes as shown in FIG. 3.

As shown in this graph, the further away (dl) the end surface 36A of the catcher 36 is from the optical sensor 35, the smaller the output. its output increases (d
++d3). Then, when the end surface 36A reaches a certain distance dll, the output of the optical sensor 35 becomes a peak value (extreme value) IcM
Take ax. Furthermore, when the butt end surface 36A approaches (de
+d2), its output is conversely smaller than this peak value 1cMax. This constant distance d9 is set based on the directivity characteristics of the light emitting section 35A and the light receiving section 35B.

Therefore, the distance (d1 to d2) of the catcher 36 to the butt surface 36A of the optical sensor 35 is set so that its output IC changes within a certain range taking this peak value ICMax. There is. In other words, the rotatable range of the catcher 36 during the string-striking stroke (d+ to d2)
An optical sensor 35 is disposed at a position where the peak value IcMaX of the sensor output signal is output.

FIG. 4 is a graph showing changes in the output signal Ic of the optical sensor 35 during the string-striking process. In the 20th string-striking stroke, the distances between the optical sensor 35 and the reflective surface are d+, d[l (peak value output), d2 (string-striking point), dll, dl in Fig. 3. changes in the order of

That is, in the string-striking process in which the hammer 26 rotates toward the string 24 by pressing a key, the catcher 36 also rotates as a unit, and its wood mouth surface 36A approaches the optical sensor 35. According to this approach, an output of 80% of IcMax (first output value) is obtained at a certain time t1. Let the time of output of this first output value be tl, and the distance between the sensor catchers at this time! It's d3.

Next, by further rotation of the catcher 36, the output (peak value) of IcMaX is obtained at time t2, and then (
The sensor catcher-to-sensor catcher distance is do), and at time t3 I
An output (second output value) of 90% of cMaX is obtained (distance between sensor catchers is d4).

Then, at time t4, the hammer 26 forms a string-striking point where the string 24 is struck (the distance between the sensor catchers is d2), and the action 25 including the hammer 26 rebounds. That is, the output of the sensor 35 theoretically changes symmetrically around the string-striking point t4. However, it may differ depending on the key release timing.

Figure 5 shows the end surface 36A of the catcher 36 and the optical sensor 3.
5 conceptually shows the change in the distance d between the two.

As shown in this figure, when the string is struck, the butt end surface 36A is at a distance d2 closest to the optical sensor 35. Also,
When outputting the peak values, they are separated by a distance d8. Also, the first output value is 0.8IcMax and the second output value is 0.8IcMax. When outputting 9 I cMax x, the distances between the end surface 36A and the optical sensor 35 are d3 and d4, respectively.
is far away.

Therefore, in this player piano, during the first automatic string striking (automatic striking by driving an actuator such as a solenoid!), each optical sensor 11 (35
), the maximum value of the sensor output (peak value IcM
aX) is stored in the detection holding circuit 12, and the first output value (0,8IcMax), which is 80% of this maximum value, is
The calculation circuit 13 calculates each second output value (0,9I cMax) that is 0%.

These first output value and second output value are respectively stored in the holding circuit 1.
4.15 is output and held, and each output of the holding circuits 14 and -15 is inputted to the comparison circuit 18.19 as a reference value.

Next, when recording a performance, the action 25 is rotated by pressing a key, and the optical sensor 35 outputs a signal shown in FIG. 4 or a signal having a similar curve.

Based on the change in the second output 1c, that is, the comparison circuit 18 determines whether the sensor output signal Ic has reached the first output value.
and compare. In the determination circuit 20, when the sensor output Ic matches the first output value before outputting the peak value IcMax, the timer 21 starts timing from the time t1 of the match.

Next, when the sensor output reaches the second output value after the sensor 11 outputs the peak value IcMax, the determination circuit 22 outputs a stop signal to the timer 21. As a result, the timer 21 ends timing.

This measured time t is output from the timer 21 to the MIDI speed table 23 to obtain the string striking strength V.

Note that if the output of the optical sensor 11 passes through the peak value but does not reach the string-striking output value, it is assumed that no string was struck.

Further, the waveform of the sensor output 1c may differ due to variations in the mounting position of each optical sensor 35, variations in the light reflectance of the butt surface 36A of the catcher 36, etc.

However, from time t1 when the gearer passes the first measurement point of 80% output normalized (standardized) with respect to the peak value JcMaX of the output of each sensor 35, the output exceeds the peak value and becomes 90% of the peak value. In this embodiment, the elapsed time Δt until time t3 when the output passes the second measurement point is measured. As a result, the string striking speed by the hammer 26 can be detected accurately.

FIG. 6 shows another example of setting the first output value and the second output value in this embodiment.

As shown in this figure, the two measurement points A and B may be calculated as α% of the peak value IcMax of the sensor output. The time △t for the catcher to move between these measurement points is
This first output value αIcMax, second output value aIcMaX
It is measured by

By appropriately calculating and setting the first output value and the second output value as described above, the rotational speed of the hammer 26 immediately before the actual string production can be detected with high accuracy.

7 and 8 show a second embodiment of the invention.

This embodiment shows an example in which the present invention is applied to a string-striking speed detecting device when the sensor output does not have a peak value, that is, when the sensor output monotonically increases or decreases.

The circuit configuration of this string-striking speed detection device is shown in FIG. Moreover, FIG. 8 is a graph showing the output characteristics of the optical sensor.

As shown in FIG. 8, in this embodiment, the output Ic of the optical sensor 11 increases monotonically in response to the distance between the catcher 36 and the butt surface 36A without having a peak value during the string-striking process. do.

In the monotonically increasing part of this output, any two output values ICI, IC
In step 2, time is measured. These measurement points Ml,
The instrument is configured to measure the time interval Δt between the detection timings of M2 and detect the string striking strength ■. These two measurement points MI+
M2 can be determined by appropriate calculation based on, for example, the rate of increase in output.

As shown in FIG. 7, the output from the optical sensor 71 is held in a sensor output holding circuit 72, and the arithmetic circuit 73 calculates a first output value Ic+ and a second output value IC2 based on the output M11 of the stringing point, for example. calculate.

These output values are set as reference values in the comparison circuits 76 and 770 in the first output value setting circuit 74 and the second output value setting circuit 75, respectively, and are compared with the output of the optical sensor 71.

The output of the optical sensor 71 is the first output value Ic+ and the second output value I
When the timer 80 changes between C2 and C2, the timer 80 is started and then stopped by the comparator circuits 76 and 77, and the elapsed time Δt between these measurement points M1 and M2 is detected.

Then, this measured time Δt is converted into the actual string-strike strength V by the hammer using the MIDI accuracy table 81.

In addition, in each of the above-mentioned embodiments, calculation, storage, etc. of various output values can also be performed by a logic operation circuit such as a well-known microprocessor.

Furthermore, in the first and second embodiments described above, an example was explained in which a light reflection type sensor was used, but for example, as shown in FIG. , an ultrasonic sensor, a magnetic sensor, and the like.

<Effects of the Invention> As explained above, the performance state detection device for a keyboard instrument according to the present invention eliminates the work of attaching the hammer shutter to the hammer shank, and therefore, the work of positioning the hammer shutter and the hammer shank can be performed with high accuracy. Machining work is no longer necessary, and the number of assembly and adjustment man-hours is also reduced.

Further, the timing of detection using the optical sensor can be set immediately before the string-striking point, and the string-striking speed can be detected with high accuracy. In this case, there is no need to mount the optical sensors for all 88 keys close to the string-striking points, and complicated work such as adjustment work is unnecessary when correcting individual differences due to hammers. Adjustment becomes easier.

Also, from the output value standardized to the sensor output, 2
Since measurement points and elapsed output times are calculated, variations in detected values between each sensor can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a performance state detection device for a keyboard instrument according to a first embodiment of the present invention, FIG. 2 is a side view showing a string-striking mechanism according to the first embodiment, and FIG. A graph showing the relationship between the output of the optical sensor and the distance between the reflective surface according to the first example, FIG. 4 is a graph showing the output characteristics of the optical sensor according to the first example, and FIG. FIG. 6 is a conceptual diagram showing the distance change between the optical sensor and the catcher end surface according to the embodiment, and FIG. FIG. 7 is a block diagram showing the circuit configuration of a performance state detection device for a keyboard instrument according to the second embodiment of the present invention, FIG. 8 is a graph showing the output characteristics of the optical sensor according to the second embodiment, and FIG. 9 is a graph showing the output characteristics of the optical sensor according to the second embodiment. FIG. 2 is a side view showing a conventional string-striking speed detection device. 11... Optical sensor (detection means), 13...
... Arithmetic circuit (output value calculation means), 21 ...
...Timer (timekeeping means), 23...MIDI velocity table, 24...Strings, 25...Action (string-striking mechanism), 35...
...Photo sensor, 86...Catcher (component), 36A
...Kiguchi surface. .

Claims (2)

[Claims] (1) It is arranged close to and opposite to the component of the string-striking mechanism of a keyboard instrument that rotates when a key is pressed, and corresponds to changes in the distance between it and the component, and has an extreme value. detecting means for outputting a signal that changes by detecting the extreme value in the output signal from the detecting means, and detecting the extreme value of the first output value and the second output value output before and after the extreme value. an output value calculating means for calculating based on the above, a time measuring means for measuring the time during which the output from the detecting means changes from the first output value to the second output value, and a time interval between the measured time and the two measuring points. A performance state detection device for a keyboard instrument, comprising: a string-striking speed calculation means for calculating a string-striking speed by the string-striking mechanism based on the distance. (2) Disposed in close proximity to and facing a component of the string-striking mechanism of a keyboard instrument that rotates when a key is pressed, and outputs a signal that changes in response to changes in the distance between the component and the component. a detection means; an output value calculation means for calculating a first output value and a second output value based on a reference value of the output signal from the detection means; and a distance setting means for setting a measurement point distance with respect to the reference value. , a timer for measuring the time during which the output from the detection means changes from the first output value to the second output value; and a timer for measuring the time during which the output from the detection means changes from the first output value to the second output value; A performance state detection device for a keyboard instrument, comprising: a string-striking speed calculation means for calculating a string-striking speed;