JPH0664454B2 - Key touch detection device for keyboard instruments - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key touch detecting device for a keyboard musical instrument, which sequentially detects the movement of a key when a key is pressed or released.

[0002]

2. Description of the Related Art As a conventional method for detecting a key touch of a keyboard instrument, a method using a mechanical switch, a piezoelectric element, a hall element or the like is known.
For example, the mechanical switch is ON, which detects the start and end of key depression and transmits a signal to another control mechanism.
Used as an OFF switch. Further, in the piezoelectric element or the hall element, it is possible to sequentially detect the strength of keystroke and the movement of the key at the time of key depression or key release by utilizing the electrical characteristics thereof.

[0003]

However, although the mechanical switch and the piezoelectric element can detect the movement of the key over time, they directly detect the movement of the key. The delicate touch of the key directly affects the sound, which may adversely affect the sound.

On the other hand, each member used in the keystroke mechanism of a piano is often hand-crafted by a skilled worker, and the keystroke mechanism of each key has mechanical variations, although it is very slight. . Therefore, it is most preferable to make a detection element having an output characteristic that matches an individual key and attach it to each keystroke mechanism. However, each of the detection elements has a constant electric characteristic or is fixed. However, the output characteristics could not be subtly changed according to each of the above keystroke mechanisms.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to detect the strength of key touch, the start and end of key depression, the start and end of key release, and the time of key depression and key release. Another object of the present invention is to provide a key touch detection device for a keyboard instrument capable of non-contactly detecting changes in the movement of keys per unit time.

Another object of the present invention is to provide a key touch detecting device for a keyboard instrument, which can easily make subtle changes in output characteristics in accordance with mechanical variations of each key. .

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above objects, and its gist is a keyboard for detecting a change in the movement of a key per unit time during key depression and / or key release. A key touch detection device for a musical instrument, wherein a light reflecting means is provided on either one of an operating portion of a keyboard musical instrument that is interlocked with the movement of the key by a key operation and a non-operating portion that maintains a stationary state by a key operation. On the other hand, on the other hand, a light emitting means for emitting light in a certain direction toward the light reflecting means and a light receiving means for receiving the reflected light are provided, and the surface of the light reflecting means reflects light having position information. In the key touch detecting device for a keyboard instrument, the position information means is formed along the operating direction of the light reflecting means or the light emitting and light receiving means.

The light having the positional information is light that reflects a relative positional change between the light reflecting means and the light emitting / receiving means as a change in the light intensity, wavelength or the number of light pulses. Say. Further, as the position information means for reflecting the light having such position information, there are a shade of color, a color, an inclined surface, a bar code and the like.

[0009]

On the surface of the light reflecting means, there is provided position information means in which the shade of color, the color, or the distance between the light receiving means and the light reflecting means, etc. are sequentially changed along the operating direction of the light reflecting means. Light is emitted from the light emitting means in a fixed direction toward the position information means. For this reason, the intensity of the light reflected from the light reflecting means, the wavelength of the light, and the like change with the positional displacement relative to the light reflecting means, and this change is detected by the light receiving means. Based on the detection result, it is possible to detect the start and end of key depression, the start and end of key release, and the change in the movement of the key per unit time.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A key touch detecting device for a keyboard instrument according to the present invention will be described with reference to the accompanying drawings.

FIG. 1A schematically shows a key tapping mechanism of a piano equipped with a key touch detection device. The key touch detection device is a reflection type optical sensor fixed together with a printed circuit board 5 to a screen 1 as a light reflection means fixed to a side surface of a tip portion of a back check 3, and a fixed shaft 4 fixed to a non-operation part of a piano. 2, the screen 1 slides in the direction of arrow X in conjunction with the back check operation while maintaining a parallel state with the optical sensor 2, that is, maintaining a constant distance.

On the surface of the screen 1, light and shade of color as position information means are arranged in order along the operating direction of the screen 1. The optical sensor 2 is an infrared ray LE as a light emitting means that emits light in a fixed direction toward the screen 1.
It is composed of D2a and a phototransistor 2b as a light receiving means for receiving the reflected light from the screen 1 (FIG. 3). In addition to the infrared LED and the phototransistor, a visible light LED and a photodiode may be used.

In the detection mechanism of this device, when the screen 1 slides in the direction of the arrow X in conjunction with the operation of the back check 3 in response to a key operation, the intensity of the reflected light changes depending on the shade of the screen 1. To do. The reflected light enters the phototransistor 2b and is converted into a current value according to the intensity of the reflected light. In this case, since the screen 1 is interlocked with the rotational movement of the wippen 9, it does not move linearly but reciprocates in a gentle arc shape. May be curved.

In an actual key operation, first, when the key 6 is pushed up, the end 6a of the key 6 is pushed up (in the direction of arrow Y) with the balance pin 7 as a fulcrum. As a result, the capstan button 8 pushes the wippen 9 upward, and the wippen 9 rotates about the fixing pin 9a in the arrow Z direction. The rotation of the wippen 9 pushes the jack 10 upward, and the pushing force is applied to the bad 1
1 rotates, and a hammer 12 fixed to the outer periphery thereof rotates to hit a string 13. When the key release operation is performed, each movable member performs an operation substantially opposite to the above operation and returns to the steady position.

During this key operation, since the screen 1 is fixed to the back check 3 fixed to the wippen 9,
The screen 1 interlocks with the movement of the wippen 9 and reciprocates along the arrow X direction. At the start of key depression, the color density near the end of the screen 1 is A, the reflected light is incident on the phototransistor 2b, and the converted current is Ia. Further, since the portion irradiated by the infrared LED 2a moves as the screen 1 moves, the tone density of the irradiated screen 1 also changes in the order of B, C, D, E, and the phototransistor 2b to which this reflected light enters. Output current of Ib, I
c, Id, and Ie in that order (FIG. 1 (b),
(C)).

By performing the optical detection in this way, it is possible to sequentially detect a relative positional change between the optical sensor 2 and the screen 1 as a change in the intensity of the reflected light, thereby starting the key depression. It is possible to detect the end of the key depression, the end of the key release to the end of the key release, or the change in the movement of the key per unit time during this period in a non-contact manner.

If colors are sequentially changed on the surface of the screen 1 instead of shades of color, the wavelength of the reflected light changes according to the colors. Therefore, if the reflected light is received by using the photodiodes having different sensitivities with respect to the wavelengths, it is possible to detect the reflected light similarly to the case of the light and shade of the color.

In FIG. 1C, point A is taken as an example.
Although the plots are made from the point to the point E, the movement progress of the screen 1 can be detected in more detail by shortening the sampling time interval. Further, if it is desired to modify the output characteristic, it can be easily modified by changing the shade of color or the state of change in color.

The output currents of these optical sensors 2 are A / D
It may be passed through a converter or input to a transistor or an IC, and input to a microcomputer or the like as an ON signal or an OFF signal depending on the value of the threshold level voltage to perform data processing. Other,
It is also possible to convert the output current of the optical sensor 2 into a voltage change and store it as an analog signal on a magnetic tape or the like.

FIG. 2A shows another embodiment. In this embodiment, an inclined surface 1'a is formed on the screen 1'as position information means, the distance between the screen 1'and the optical sensor 2 is changed, and the screen 1'is determined from the intensity of the reflected light.
The position of is detected.

As shown in FIG. 2 (b), the screen 1'has a wedge shape with a substantially triangular vertical section and is fixed to the tip of the back check 3. Also,
The optical sensor 2 is arranged above the inclined surface 1'a of the screen 1'relative to the inclined surface, and in parallel with the triangular wedge-shaped base 1'b of the screen 1 ', the printed circuit board 5 is provided. It is also fixed to the fixed shaft 4.

The detection mechanism of this apparatus is such that when the screen 1'is moved in parallel with the operation of the key 6 in parallel with the base 1'b of the triangular wedge, that is, in the direction of the arrow X ', the inclined surface 1'. Because of a, the distance between the screen 1'and the optical sensor 2 changes, and the intensity of the reflected light changes accordingly. If the intensity of this reflected light is detected by the phototransistor 2b, the relative positional change between the photosensor 2 and the screen 1'can be sequentially detected as the change in the output current I of the photosensor 2 (see FIG. 2 ( c)). Therefore, even when the screen 1'is used, the relative positional change between the optical sensor 2 and the screen 1'can be detected optically in succession, whereby the start of key depression, the end of key depression, and the start of key release. Thus, it is possible to detect the end of the key release, or the change of the key movement per unit time during this period without contact.

In this case, since the screen 1'is interlocked with the rotational movement of the wippen 9, it does not move linearly but reciprocates in a gentle arc. Therefore, it is preferable to correct this arcuate movement and design the inclination of the inclined surface 1'a so that the distance between the screen 1'and the optical sensor 2 becomes proportional to the movement of the screen 1 '. . Further, when it is desired to change the output characteristic of the optical sensor 2 in accordance with the mechanical variation of each keystroke mechanism, it can be easily changed by changing the inclination state of the inclined surface 1'a.

In each of the above-mentioned embodiments, as the light reflecting means for reflecting the light having the positional information, the shade of the color, the color or the inclined surface has been exemplified. It is also possible to use a black-and-white or uneven bar code, and in this case, it is possible to detect a change in the movement of the key per unit time by counting the light pulses of the reflected light. When it is desired to correct the output characteristics of the optical sensor according to the mechanical variation of each keystroke mechanism, for example, in the case of a black and white barcode, the white / black interval or each width is changed. This can be done easily.

Further, in each of the above-described embodiments, the screens 1 and 1'are attached to the back check 3, but the present invention is not particularly limited as long as it is an operating portion that operates by key operation. , The capstan button 8, the wippen 9, the pad 11, the hammer 12, and the like. In addition, instead of attaching a screen, you can directly apply color shades and colors to the operating part of the piano,
Alternatively, the irregularities may be formed directly. Further, in each of the above-described embodiments, the screens 1 and 1'are attached to the operating portion of the piano and the optical sensor 2 is attached to the non-operating portion. However, on the contrary, the optical sensor 2 is attached to the operating portion and not operating. Even if the screens 1 and 1'are attached to the parts, the same effect can be obtained.

[0026]

According to the key touch detecting device for a keyboard musical instrument of the present invention, the light reflecting means is provided on one of the operating portion of the keyboard musical instrument which is operated by a key operation and the non-operating portion which is kept stationary by the key operation. In order to reflect light having position information on the surface of the light reflecting means, the light emitting means that emits light in a fixed direction toward the light reflecting means and the light receiving means that receives the reflected light are provided on the other side. The position information means is formed along the operating direction of the light reflecting means or the light emitting and light receiving means.

Therefore, by modifying the position information means, the output characteristics of the light receiving means can be freely created, and the key touch that matches each key according to the mechanical variation of each keying mechanism. One set of detectors can detect the strength of the key, the start of the key depression to the end of the key depression, the start of the key release to the end of the key release, and the change of the key movement during the key depression or during the key release per unit time. It is possible to detect all. Further, since the key touch detection device according to the present invention optically detects a key touch, it can be detected in a non-contact manner, and has an excellent effect such that a delicate touch of a key is not adversely affected. .

[Brief description of drawings]

1 (a) is a schematic explanatory view showing a piano equipped with a key touch detection device according to the present invention, FIG. 1 (b) is a front view showing a screen, and FIG. 1 (c) is a screen. 5 is a graph showing the output current of the phototransistor with respect to the color density of FIG.

FIG. 2 (a) is a schematic explanatory view showing another embodiment,
2B is a sectional view showing another screen, FIG.
(C) is a graph showing the output current of the phototransistor with respect to the distance between the screen and the optical sensor.

FIG. 3 is an explanatory diagram schematically showing the configuration of an optical sensor.

[Explanation of symbols]

 1, 1'Screen (light reflecting means) 2a Infrared LED (light emitting means) 2b Phototransistor (light receiving means)

Claims (1)

[Claims] 1. Unit time for key depression and / or key release
A key touch detection device for a keyboard instrument that detects changes in the movement of a key, and a stationary state is maintained by the operation part of the keyboard instrument that is interlocked with the movement of the key by key operation and by the key operation. of the non-operating portion, either one set <br/> only the light reflecting means to Rutotomoni, on the other, the light emitting means and light receiving means for receiving the reflected light emits in a certain direction toward the light reflecting means the provided, on a surface of said light reflecting means, said light reflecting means or the light emitting position information means for reflecting light having position information, and forming along the actuation direction of the receiving means Key touch detection device for keyboard instruments.