JPH06149234A - Hammer action detecting device of keyboard musical instrument - Google Patents

Abstract

PURPOSE:To provide the hammer action detecting device of the keyboard musical instrument which can detect a hammer action continuously with high precision and is easily manufactured and adjusted. CONSTITUTION:An action detection part 19 consists of a shutter 21 which is fitted to a hammer shank 13 and projects upward and an optical detection part 23 which is fitted opposite the shutter 21 to a base 17 and projects downward. This shutter 21 is a plate type member made of translucent plastic and its lower part is increased in black density so that the quantity of transmitted light decreases. The optical detection part 23, on the other hand, is provided with both wall parts 23a and 23b in parallel; and a light emitting diode 25 which emits spot-shaped light is arranged at one wall part 23a and a phototransistor 27 which photodetects the light emitted by the light emitting diode 25 and outputs a voltage signal corresponding to the quantity of photodetected light is arranged at the other wall part 23b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hammer motion detecting device for a keyboard instrument, which can detect the motion of a hammer such as an automatic playing piano with high accuracy.

[0002]

2. Description of the Related Art Conventionally, in a keyboard instrument such as an automatic playing piano, a hammer motion such as a hammer speed is detected in order to detect a performance state, record or control reproduction of a performance. Various detection devices have been proposed to detect this hammer motion.

For example, a detection device is known in which a shutter for shielding light transmission is attached to a hammer shank, and a pair of transmission type phytointerrupters for switching light shielding or transmission according to movement of the shutter are attached. ing. Alternatively, in recent years, a hammer shank is irradiated with light, the reflected light of the irradiated light is received, and a detection is performed using a reflective photosensor that detects the operation of the hammer by an electric signal output according to the received light. A device has been proposed.

[0004]

However, these conventional techniques are not suitable because the hammer motion cannot always be detected accurately. That is, in the above-mentioned technique, the hammer speed is detected based on the time lag of the light shielding timing by the pair of photointerrupters, and the string striking strength is estimated from the hammer speed.
Since the string striking strength (the speed at which the hammer hits the string) is estimated by discrete data, the string striking strength could not be detected accurately.

That is, in order to detect the striking strength ideally, it is necessary to detect the hammer speed at the moment when the hammer hits the string. However, in the conventional method, only the average speed between two points before hitting is detected. Since it cannot be obtained, there is a problem that it is not possible to record a precise performance close to the actual performance. Further, since the hammer speed cannot be continuously detected, there is a problem that the hammer speed cannot be feedback-controlled to perform accurate regeneration control.

In the above technique, the hammer speed can be continuously detected, but since the reflection type photosensor is used, it is difficult to actually adjust the hammer speed, which is not always realistic. Furthermore, in the reflective photo sensor,
Even if the distance between the sensor and the hammer is slightly different, the output voltage is greatly different, and there is also a problem in that the variation for each hammer becomes large.

The present invention has been made in order to solve the above problems, and provides a hammer motion detecting device for a keyboard instrument, which can detect a hammer motion continuously and with high accuracy, and which is easy to manufacture and adjust. The purpose is to

[0008]

The present invention for achieving this object, as illustrated in FIG. 1, is such that each hammer or interlocking mechanism interlocking with each hammer of a keyboard instrument, or facing the hammer or interlocking mechanism. A shutter M1 mounted at a position where the transmission state of light continuously changes along the moving direction of the hammer or the interlocking mechanism, and irradiates the shutter M1 with light and receives light transmitted through the shutter M1. Based on the state of the received light, a light detecting means M2 for outputting an electric signal relating to the position of the hammer, and an operation including the position of the hammer are detected based on the electric signal outputted from the light detecting means M2. Motion detection means M3
The gist is a hammer motion detection device for a keyboard instrument, which is characterized by including:

Examples of the keyboard musical instrument include various keyboard musical instruments that perform a performance using a hammer, such as an automatic piano. Further, as the shutter, one in which the amount of transmitted light continuously changes in the moving direction can be cited. For example, the shutter is composed of a semitransparent filter, and the shade of the shutter gradually changes, and the shutter It is possible to employ a shape in which the light non-transmitting portion is formed into a shape such as a triangle or a smooth curve, and a portion where the light non-transmitting portion is formed with fine dots and the number of dots is gradually changed.

[0010]

The hammer motion detecting device for a keyboard instrument of the present invention having the above-described structure includes each hammer of the keyboard instrument or an interlocking mechanism interlocking with the hammer, or a shutter M1 attached at a position facing the hammer or interlocking mechanism. Cage,
The shutter M1 is configured such that the light transmission state continuously changes along the moving direction of the hammer or the interlocking mechanism.

Then, the light detecting means M2 irradiates the shutter M1 with light, receives the light transmitted through the shutter M1, and outputs an electric signal relating to the position of the key based on the received light. Further, based on the electric signal output from the light detecting means M2, the movement detecting means M3 detects the movement of the hammer including the position of the hammer.

That is, according to the present invention, the operation of the hammer is detected by the relative position between the shutter M1 and the light detecting means M2 in which the light transmission state continuously changes, and the shutter M1 causes the light detecting means M2 to operate. Since the state of the input light changes, this change is taken out as an electric signal to continuously detect the operation of the hammer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the hammer motion detecting device for a keyboard instrument of the present invention will be described below. FIG. 2 shows a part of the configuration of an automatic playing piano to which a hammer motion detecting device as an embodiment is applied, and FIG. 3 shows a motion detecting section.
FIG. 4 shows the operation, and FIG. 5 shows a circuit diagram of the photodetector.

As shown in FIG. 2, an automatic playing piano 1 to which this embodiment is applied is a grand piano, and a shelf board 3 and
A key (key) 5 swingably mounted on the shelf board 3, an action mechanism 7 arranged above the rear end of the key 5, and a key 5
Solenoid 9 arranged below the rear end to drive the key 5
A string 11 arranged above the action mechanism 7, a hammer shank 13 swung by the action mechanism 7, a hammer 15 attached to the tip of the hammer shank 13, and a string arranged above the hammer shank 13. The board 17 and the operation detector 19 attached to the board 17 for detecting the operation (including the position) of the hammer 15.

As shown in FIG. 3, the motion detector 19 has
The shutter 21 is attached to the hammer shank 13 and protrudes upward, and the photodetector (photointerrupter) 23 is attached to the substrate 17 so as to face the shutter 21 and protrudes downward.

The shutter 21 is a plate-shaped member made of translucent plastic, and the lower part has a deeper black color so that the amount of light transmission decreases. In addition, the shutter 21 is smoothly curved according to the curvature of a circle centering on the shaft 13a of the hammer shank 13 so that the center line in the longitudinal direction thereof is always located at the center of the light detecting portion 23, and In the figure, the shutter 2
The density difference of 1 is shown by the density of the lines for convenience.

On the other hand, the light detecting section 23, as shown in FIG.
The shutter 21 is formed by the left and right wall portions 23a and 23b.
Both wall portions 23a and 23b are provided in parallel to face each other so as to sandwich. One wall portion 23a of the light detecting portion 23
Is provided with a light emitting diode 25 that emits spot-shaped light to the opposite wall 23b side, while the other wall 23
A phototransistor 27 that receives the light emitted from the light emitting diode 25 (via the shutter 21) and outputs a voltage signal (output voltage) Vout according to the amount of received light is arranged in b.

The substrate 17 has a hammer shank 13
A cutout 17a is provided so that the shutter 21 does not hit the substrate 17 when the shutter moves upward. Therefore, FIG.
As shown in (a), when the hammer 15 does not strike a string, that is, when the hammer shank 13 and the shutter 21 are at the lower position, the shutter 21
Is distant from the installation position (detection position) of the light emitting diode 25 and the phototransistor 27, the light emitted from the light emitting diode 25 is directly emitted from the phototransistor 2
A large amount of light is incident on 7. Then, by the circuit as shown in FIG. 5, as shown in the graph of the relationship between the output voltage Vout in FIG. 6 and the displacement amount x (hereinafter simply referred to as displacement amount x) at the mounting position of the shutter 21 of the hammer 15, A small output voltage Vout on the left side of the graph is obtained. The a on the horizontal axis in FIG. 6 indicates the maximum value of the displacement amount x.

On the other hand, as shown in FIG. 4 (b), when the shutter 21 moves upward for a string striking operation, the lower (dark black) portion of the shutter 21 rises to reach the detection position. The amount of light transmitted through the shutter 21 decreases, and the output voltage Vout increases. Therefore, by detecting the output voltage Vout, the displacement amount x from the position of the hammer 15, that is, the reference position (before the string striking operation) can be known from the relationship shown in FIG.

Further, as shown in FIG. 2, the photo-detecting section 23 includes an electronic control unit 3 via an A / D converter 33.
In addition to being connected to 5, the output voltage Vout (indicating the displacement amount x) is differentiated to obtain a hammer speed v.
1, the differentiation circuit 31 is further connected to the A / D converter 3
3 is connected to the electronic control unit 35.

The electronic control unit 35 operates the hammer 15 according to the output voltage Vout from the photodetector 23, as will be described later.
Is an arithmetic processing device for calculating the displacement amount x of the
An input / output unit 35a for inputting / outputting data, a CPU 35b for performing various calculations, a RAM 35c for temporarily storing data and the like, a ROM 35d for storing various data conversion tables, and a bus connecting them. Line 3
5e and mainly. In addition to the A / D converter 33, a drive circuit 37 for driving various actuators such as the solenoid 9 is provided in the input / output unit 35a.
Etc. are connected.

The ROM 35d has an output voltage Vou.
A position detection table showing the relationship between t and the displacement amount x of the hammer 15, a speed detection table showing the relationship between the signal obtained from the differentiating circuit 31 and the hammer speed v, etc. are stored. Next, the operation of the hammer operation detecting device of the present embodiment having such a configuration will be described based on the explanatory view of the operation of FIG. 4 and the flowchart of FIG.

First, when the power is turned on, light is emitted from the light emitting diode 25 toward the phototransistor 27 facing the light emitting diode 25. Here, when the string striking operation is not performed (see FIG. 4 (a)), that is, when the hammer 15 and the hammer shank 13 are descending downward, the light is not blocked by the shutter 21, so the photo is taken as it is. Reach transistor 27. Therefore, the output voltage Vout
Remains below 0.3 [V] of the output shown in the lower part of the graph of FIG.

Next, when the string striking operation is performed, the hammer 1
Since 5 moves upward depending on the string striking speed, the shutter 21 also moves upward (see FIG. 4B). With this movement, the lower (dark black) portion of the shutter 21 gradually rises and the amount of light transmission gradually changes (in this case, decreases), so that the amount of light received by the phototransistor 27 decreases. As a result, the output voltage Vout gradually increases and gradually moves to the output shown in the upper part of the graph of FIG.

The output voltage Vout is converted into a digital signal by the A / D converter 33 and directly input to the electronic control unit 35. In another path, the output voltage Vout is once differentiated by the differentiating circuit 31, A / D converter 3
3 is converted into a digital signal by the electronic control unit 3
5 (step 100 in FIG. 7).

In the electronic control unit 35, the current position of the hammer 15 (that is, the displacement amount x from the reference position) is detected by referring to the position detection table stored in the ROM 35d according to the directly input signal. (Step 110),
The detected value is temporarily stored in the RAM 35c together with the time data.
(Step 120).

On the other hand, according to the differentiated signal, RO
While referring to the speed detection table stored in M35d, the current hammer speed v is detected (step 13
0), the maximum value vmax of the speed v is obtained (step 14
0), the hammer speed v and the maximum value vmax thereof are temporarily stored in the RAM 35c together with the time data (step 15).
0).

Then, such processing is repeated every very short period to obtain precise string striking data. The displacement amount x with respect to this time and the hammer speed v obtained by differentiating the displacement amount x are shown in the timing chart of FIG. 8. The displacement amount x is the maximum at the time t ₀ when the string is struck. In addition, it can be seen that the hammer speed v becomes maximum immediately before the hammer 15 contacts the string 11, and then the hammer speed v rapidly decreases.

As described above, in this embodiment, the output voltage Vout from the photodetector 23 is detected and the detected output voltage Vo is detected.
Hammer 1 referring to the position detection table based on ut
Since the displacement amount x of 5 can be obtained, this displacement amount x
Therefore, the position of the hammer 15 can be accurately detected.

Further, based on the signal from the differentiating circuit 31,
Since the hammer speed v can be detected accurately and continuously by referring to the speed detection table, precise feedback control of the reproducing operation can be performed based on the continuous speed data. In particular, by obtaining the maximum value vmax of the hammer speed v, it is possible to obtain a precise string striking strength immediately before tapping, so that there is a remarkable effect that an accurate performance can be recorded.

Further, in the case of this embodiment, since the shutter 21 may be simply arranged so as to block the optical path, its manufacture and adjustment are easy, and based on the obtained output signal Vout, the individual hammers. There is an advantage that the variation of 15 can be corrected. In addition, since the value of the output voltage Vout can be freely changed by changing the pattern of the change in the amount of light transmission of the shutter 21, it is possible to correct the variation for each hammer 15.

In the case of the operation after striking a string, the output voltage V is increased because the amount of light transmission gradually increases, contrary to the above-mentioned string striking operation.
out decreases, and the hammer 15 is released according to the output voltage Vout.
It is also possible to obtain the displacement amount x and the speed v of the. Also,
In the present embodiment, the hammer speed v is continuously detected and the value is stored, but as another means other than that, for example, a well-known peak hold circuit is connected to the differentiating circuit 31, and the value shown in FIG.
In the procedure shown in (1), only the maximum value vmax of the hammer speed v may be stored from the output showing the held peak.

Next, another embodiment will be described. However, this embodiment is the same as the above embodiment except for the shutter, and will be briefly described. As shown in FIG. 10, in the shutter 30 of this embodiment, a portion that blocks light transmission is obliquely formed in a substantially trapezoidal shape. This also allows the amount of transmitted light to be gradually changed with the movement of the shutter 30, so that the same effect as the above-described embodiment can be obtained.

Next, another embodiment will be described. However, this embodiment is the same as the above embodiment except for the shutter, and will be briefly described. As shown in FIG. 11, in the shutter 40 of this embodiment, the portion that blocks the transmission of light is obliquely and rapidly curved. This also allows the amount of transmitted light to be gradually changed with the movement of the shutter 40, so that the same effect as that of the above-described embodiment can be obtained.

The present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be carried out in various modes within the scope of the gist of the present invention. For example, in each of the above-described embodiments, the shutter is attached to the hammer shank side, and the photodetector is attached to the substrate side facing the shutter.
The light detector may be attached to the hammer shank side and the shutter may be attached to the substrate side.

Further, the shutter and the photodetector may not be directly attached to the hammer shank or the substrate, but may be attached to a member or the like that moves in conjunction with the movement of the hammer. Further, in the above-described embodiment, the light transmission amount is increased toward the tip end side of the shutter, but conversely, the light transmission amount may be decreased toward the tip end side. .

[0037]

As described in detail above, in the hammer motion detecting device for a keyboard instrument according to the present invention, a shutter whose light transmission state continuously changes and an electric signal depending on the light transmitted through this shutter are provided. Since it is equipped with a light detection unit that outputs a signal and a motion detection unit that detects the motion of the hammer based on an electrical signal from the light detection unit, it is possible to continuously and precisely detect the motion of the hammer including the position of the hammer. You can
Therefore, since performance information such as precise string striking speed can be obtained based on the detected hammer motion, accurate feedback control of the hammer motion is performed based on this performance information to reproduce an excellent performance. There is a remarkable effect that can be.

Further, the present invention has an advantage that the shutter can be easily attached and the structure is simple because only one set of the photodetector is required. Furthermore, the value of the output voltage can be freely changed by changing the pattern of the change in the amount of light transmitted through the shutter, so that it is possible to correct the variation for each hammer.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of the present invention.

FIG. 2 is an explanatory diagram showing a hammer motion detecting device of the present embodiment.

FIG. 3 is an explanatory diagram showing an operation detection unit.

FIG. 4 is an explanatory diagram showing an operation of an operation detector.

FIG. 5 is a circuit diagram showing an operation detector.

FIG. 6 is a graph showing a relationship between an output voltage and a displacement amount of a hammer.

FIG. 7 is a flowchart showing a basic operation of the hammer operation detecting device.

FIG. 8 is a timing chart showing a basic operation of the hammer operation detecting device.

FIG. 9 is a block diagram illustrating another configuration of the embodiment.

FIG. 10 is an explanatory diagram showing a shutter according to another embodiment.

FIG. 11 is an explanatory diagram showing a shutter according to still another embodiment.

[Explanation of symbols]

1 ... Automatic playing piano 5 ... Keys 19 ... Motion detectors 21 and 3
0, 40 ... Shutter 23 ... Photodetector 35 ... Electronic control device

Claims (1)

[Claims] 1. A hammer of a keyboard instrument or an interlocking mechanism interlocking with the hammer, or a position attached to the hammer or interlocking mechanism so as to face the hammer or interlocking mechanism, and a light transmission state is continuous along the moving direction of the hammer or interlocking mechanism. And a light detecting unit that irradiates the shutter with light and receives the light transmitted through the shutter, and outputs an electric signal related to the position of the hammer based on the state of the received light. A hammer motion detecting device for a keyboard instrument, comprising: a motion detecting unit that detects a motion including a position of the hammer based on an electric signal output from the detecting unit.