JP3260981B2 - Key pressing speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a piano capable of outputting an electronic sound in response to a struck string, and detects a key-pressing speed required for setting the generation timing of the electronic sound and the volume of the electronic sound. The present invention relates to a key pressing speed detection device.

[0002]

2. Description of the Related Art Conventionally, an acoustic piano has been combined with an electronic sound source, and in addition to the usual performance by striking a string,
There has been proposed a composite piano that can be played by an electronic sound source.

[0003] In such a complex type piano, if the stringing sound is stopped and the performance sound from the electronic sound source based on the keyboard operation is played while listening to the sound with headphones or the like, the performance sound does not leak outside, and in an apartment house or a densely populated area of a house. There is an advantage that the user can freely perform the music or practice at night. The stopping of the stringing sound is performed by stopping the hammering operation of the hammer based on the key depression at a predetermined position, so that it is possible to play without damaging the touch of the keyboard.

In order to make the playing feeling of the electronic sound close to the playing feeling of the striking of the strings, an electronic sound is generated at an optimal timing in accordance with the key being pressed, and the strength of the key pressing (that is, the key pressing speed) is reduced. It is necessary to generate an electronic sound at an optimal volume accordingly. In order to detect these, in a conventional composite piano, a key pressing speed detecting device is provided for each key as shown in FIG.

The key-pressing speed detecting device comprises a photo interrupter 61 having two parallel optical axes and a shutter 63 for appropriately blocking the optical axis. The shutter 63 is fixed to the lower surface of the keyboard 71 by soldering to the surface of the printed circuit board 69 fixed via the frame 67. FIG. 7A is an enlarged view of the portion C.

The photointerrupter 61 has a light emitting element (for example, an infrared light emitting diode) and a light receiving element (for example, a phototransistor) opposed to each other, runs an optical axis therebetween, and detects a cut-off or conduction of the optical axis. Interrupter 1
Is a seed. As shown in FIG. 7 (b), which is a view taken in the direction of arrow B in FIG. 7 (a), the shape is a U-shape when viewed from below. I have a book. A circuit is formed by performing predetermined wiring, and an output terminal is separately provided so that the voltage increases when each optical axis is cut off and decreases when the optical axis is turned on.

On the other hand, the shutter 63 is a plate-shaped member provided with a hole 73 as shown in FIG. Hole 73
The shape of the edge 73 is two substantially horizontal portions having a height difference.
a, 73b at the bottom. When the shutter 63 enters between the opposing surfaces of the photointerrupter 61 and the keyboard is not pressed, the two optical axes 75a and 75b are cut off below the hole 73 (marked by "x" in FIG. 7A). When the key is locked, the shutter 63 is lowered together with the keyboard 71, and the edges 73a, 73b are retracted downward and are fixed at positions where the optical axes 75a, 75b are conducted. For this fixing, a pointed portion 63a is provided on the upper portion of the shutter 63, and a hole 72 having a diameter smaller than the width of the pointed portion 63a is formed on the lower surface of the other keyboard 71.
This is done by typing a.

When the key is depressed, the keyboard 1 is moved to the balance pin 7
7 (see FIG. 6), the shutter 63 moves downward with the fulcrum as a fulcrum, and the shutter 63 moves downward.
a and 75b are conducted through the hole 73. This conduction is
Since the adjustment is performed at the edges 73a and 73b having a difference in height, a time difference substantially in inverse proportion to the key pressing speed occurs. This conduction is observed from a change in the output voltage of the photointerrupter 61, and a time difference is measured. By calculating the time difference, a key pressing speed can be obtained. At the same time, the key depression is also detected, so that the timing of sound generation can be set in synchronization with the conduction of the optical axis 75a (that is, the later conduction). Since this detection is performed in a non-contact manner, the touch of the keyboard 71 is not adversely affected, and the performance by the electronic sound can be performed with a feeling similar to the performance by the striking sound.

[0009]

As can be seen from the configuration described above, the shutter 63 and the photo interrupter 61
, The timing and volume of the generated electronic sound change. Therefore, in order to generate an appropriate electronic sound, it is necessary to optimally adjust the relative positions. For this purpose, the volume and timing of the electronic sound may be adjusted so as to match the volume and timing of the stringing sound generated by pressing the key at the same speed.

[0010] However, the piano uses many kinds of woods such as spruce, maple, hippo, etc. only for the striking mechanism.
Such a portion using a large amount of natural materials has a greater variation than a portion made of only metal or resin. Therefore, an adjustment step of adjusting the timing and volume of the electronic sound to match the variation in the key press feeling at the time of playing by stringing is indispensable for each key.

In the above-described conventional key pressing speed detecting device, it takes a great deal of trouble and time to make this adjustment. That is, if the generated electronic sound is too loud compared to the key pressing speed, the lower edge 73b of the hole is cut by a predetermined amount, and if the sound generation timing is late, both edges 73a and 73b are cut.
The same amount (both are cut off the edge 73 near the keyboard)
If only a is removed, the height difference becomes small and the volume becomes large).

When performing the reverse correction, that is, when a correction to raise the edge is required, such as when the volume is too low or when the timing is too early, another plate is attached to the hole 73 to make it seem apparently. It is necessary to take measures such as raising the edge or replacing the shutter 63 itself. Moreover, since the shutter 63 is driven into the lower surface of the keyboard 71, the shutter 63 is
It is necessary to perform a troublesome operation of pulling out from the lower surface and performing the above-described correction, and then bonding and fixing it to the keyboard 71 again. The number of keyboards 71 is representative, and there are 88 white keys and black keys, and it is a very complicated task to optimize all of these timings and volumes.

As another method, a shutter 63
Even if it is attempted to adjust not the photo interrupter 61 side but the photo interrupter 61 side, since the photo interrupter 61 is soldered to the printed circuit board 69 provided above the reed 65, it is difficult to move the photo interrupter 61 to adjust the volume and timing. It is very difficult. If the photointerrupter 61 is to be moved up and down together with the printed circuit board 69, this adjustment must be performed for each key as described above. Therefore, the printed circuit board 69 must be divided into 88 parts. Aside from the mechanism, fixing and connecting the divided printed circuit boards become very complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a key-pressing speed detecting device in which the trouble of performing the above-mentioned adjustment is reduced.

[0015]

Means for Solving the Problems According to the first aspect of the present invention, which has been made to achieve the above object, the invention is provided by providing two light-emitting elements and two light-receiving elements below a keyboard. A photointerrupter for running two optical axes horizontally in parallel, and a plate-like member fixed to the lower part of the keyboard to block both of the two optical axes, each of which has a time lag when the keyboard is pressed. And a shutter provided with a hole having a predetermined shape at a position where the shutter is released, wherein the shutter is fixed directly to the keyboard and the shutter plate having the hole and supports the shutter plate. It consists of a plate supports, moreover the shut
Ter plate, to the upper Symbol photointerrupter, the
Characterized in that it is relatively movably supported by the plate supports.

According to a second aspect of the present invention, in the key pressing speed detecting device according to the first aspect, the number of the holes is one, and the lower edges of the holes block the one optical axis. The plate support portion movably supports the shutter plate in parallel with the edge of the two edges closer to the keyboard. It is characterized by.

According to a third aspect of the present invention, in the key depression speed detecting device according to the first aspect, the number of the holes is one, and the lower edge of the hole has a linear shape. However, the present invention is characterized in that the shutter plate is supported so as to be movable non-parallel to the straight line of the lower edge of the hole.

[0018]

In the key depression speed detecting device according to the first aspect of the present invention, when the key is not depressed, the shutter plate fixed to the keyboard via the plate supporting portion is connected to the shutter plate. The two optical axes of the photointerrupter are blocked at a portion below the hole of the photointerrupter. When you press the key, the shutter plate moves down,
The block is released through the two optical axes through the hole. This release is performed with a time difference because the distance between each optical axis and the lower edge of the hole is different.

When the shutter plate is moved relative to the photo-interrupter by the plate supporting portion which supports the shutter plate so as to be relatively movable with respect to the photo-interrupter, the distance between each optical axis and the lower edge of the above-mentioned hole becomes smaller. Each changes. If the relative movement is made so that the difference between the two distances is reduced, a kind of erroneous detection will occur and the measured value of the speed will increase.If the relative movement is made so that the larger of the two distances is further increased, the push will be made. An erroneous detection is made as if the key timing was delayed.

That is, by moving the shutter plate relative to the photointerrupter, it is possible to easily change the key pressing speed and the timing detection amount without removing the shutter plate. According to a second aspect of the present invention, before the key is pressed, the two optical axes are blocked by the shutter plate in the same manner as in the first aspect of the invention, and when the key is pressed, the shutter plate is detected. The two edges at the lower edge of the hole have conduction through one optical axis after a predetermined time.

Since the shutter plate is moved in parallel to the one of the two edges closer to the keyboard, when the shutter plate is moved, the distance between the edge closer to the keyboard and the corresponding optical axis does not change. However, since the far edge is non-parallel to the near edge, the corresponding distance to the optical axis changes with movement. That is, the generation timing of the electronic sound set by the conduction of the optical axis by the edge closer to the keyboard does not change, but only the volume set by the distance difference, that is, the time difference of the conduction changes.

That is, by moving the shutter plate parallel to the photointerrupter as described above, it is possible to easily adjust only the sound volume without changing the generation timing of the electronic sound. According to the third aspect of the present invention, the key pressing speed detecting device is configured to perform two key presses before the key is pressed, similarly to the first aspect of the present invention.
When one of the optical axes is interrupted and a key is pressed, a hole in the shutter plate allows the two optical axes to conduct. The two optical axes are inclined so as not to be horizontal during conduction so that conduction is performed with a time difference.

When the shutter plate is moved with respect to the plate support, the shutter plate is translated in a direction different from the direction of the linear lower edge of the hole. Therefore, the distance between each optical axis and the lower edge changes, but the difference between the two distances does not change. That is, the volume set by the conduction time difference generated when a key is depressed does not change, and only the sounding timing set by the later conduction changes between the two conductions.

That is, by moving the shutter plate parallel to the photointerrupter as described above, it is possible to easily adjust only the generation timing without changing the volume of the electronic sound.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a key pressing speed detecting device 1 to which the present invention is applied.
FIG. FIG. 1A is an enlarged view of the keyboard and the periphery of the key pressing speed detecting device 1 arranged below the keyboard, similarly to FIG. 7, and the right side in the figure is the front of the piano, and the upper side in the figure is the upper side. Above the piano. 1B is an enlarged view of FIG. 1A as viewed from an arrow A, and FIG. 1C is an enlarged view of FIG. 1A as viewed from an arrow B. It is assumed that the piano to which the key pressing speed detecting device 1 is applied is placed on a horizontal surface.

As shown in FIGS. 1A and 1B,
The key pressing speed detecting device 1 includes a photo interrupter 11, a shutter plate 13, and a plate support 15. The photo interrupter 11 is provided with the photo interrupter 6.
It is exactly the same as 1. That is, when viewed from above, it has a U-shape, and two optical axes 17 are provided between the opposing surfaces.
The light emitting device and the light receiving device are provided in two sets so that the light emitting devices a and 17b run horizontally. A predetermined circuit (not shown) is wired to this, and when the optical axis is cut off, the voltage rises and the cutoff is released, that is, when the optical axis is turned on, the output that decreases the voltage is made to correspond to each optical axis. Two can be taken out.

The shutter plate 13 has a pentagonal hole 1
Reference numeral 9 denotes a plate-like member in which wavy irregularities are formed on the upper tongue piece 21. The pentagon of the hole 19 is composed of a horizontal side 19a at the lower edge and an oblique side 19b which is lowered as the distance from the side 19a, and the remaining three sides are one horizontal upper side and the upper side and the lower side. It consists of a vertical side connecting the two sides of the edge. The wavy unevenness formed on the tongue piece 21 is such that the direction of each ridge line and valley line is substantially parallel to the vertical direction of the keyboard.

The plate supporting portion 15 is formed by bending a long plate-like member made of a soft synthetic resin at a central portion in the longitudinal direction and substantially overlapping the plate-like member. As shown in FIG. Used with Below the bending position, a through hole is provided that penetrates both of the substantially superposed members. The plate support portion 15 is located slightly below the through hole.
The wavy irregularities reaching slightly above the lower end of are provided on the substantially overlapped surface. As shown in FIG. 1C, the wavy irregularities are in close contact with the wavy irregularities provided on the tongue piece 21 of the shutter plate 13 at a predetermined relative position so that the tongue piece 21 can be sandwiched.

The above components are arranged in the following positional relationship. That is, the photo interrupter 11 is a printed circuit board 2 fixed to a reed (not shown) via the metal frame 23.
5 is soldered. The shutter plate 13 enters between the opposing surfaces of the photointerrupter 11, interrupts both optical axes of the photointerrupter 11 below the hole 19, and when the shutter plate 13 moves downward by a key depression, the side The optical axis 17a is substantially at the center of the
Of the tongue 21 of the shutter plate 13 with the hexagon bolt 30 through the plate support portion 15 that sandwiches the substantially right and left centers of the tongue 21 of the shutter plate 13 in the figure so that the optical axes 17b are conducted substantially at the center of the keyboard 27. Will be concluded.

When the shutter plate 13 is sandwiched by the plate supporting portion 15, the movement in the left-right direction in the drawing can be restricted by the wavy irregularities provided on the contact surfaces of the shutter plate 13, and the irregularities are formed at the tip of the plate supporting portion. Since the shutter plate 13 is not provided, the downward movement of the shutter plate 13 can be restricted. These and the fastening force of the hexagon bolt 30 can also prevent upward and forward and backward movements in the figure. A long rectangular hole is formed in the printed circuit board 25 so that the shutter plate 13 lowered together with the keyboard 27 in response to key depression does not interfere with the printed circuit board 25 through the hole.

The setting of the generation timing and volume of the electronic sound is as follows.
By observing the falling timing of the two voltage values output from the photointerrupter 11, the key depression and the key depression speed are detected, and the detection is performed based on these. The generation timing is based on which of the two voltage values falls later, and is generated after a predetermined time from the fall. On the other hand, the volume is measured by measuring the time difference between the fall of the two voltage values and converting this to a speed or directly treating it as a physical quantity that is approximately inversely proportional to the speed. Set.

In the key pressing speed detecting device 1 constructed as described above, when the relative position between the shutter plate 13 and the photo interrupter 11 is as shown in FIGS. 2 (a) and 2 (c), the output voltage by the photo interrupter 11 is obtained. The waveforms of FIG.
2 (b) and FIG. 2 (d). However, in the waveform graph, the vertical axis represents voltage, the horizontal axis represents time, and the horizontal axis represents t =
It is assumed that the key is pressed at time 0. The output voltage corresponding to the optical axis 17a is defined as Va, and the output voltage corresponding to the optical axis 17b is defined as Vb.

That is, it is assumed that the key is depressed when the shutter plate 13 is at the position as shown in FIG. 2A with respect to the photo interrupter 11, and a voltage waveform as shown in FIG. 2B is output. That is, the key is depressed at t = 0 and the shutter plate 13 starts to descend together with the keyboard 27. At t = t1, the hypotenuse 19b reaches the optical axis 17b, the optical axis 17b is conducted, and the output voltage Vb falls. . A side 19a for conducting the other optical axis 17a is a hypotenuse 19b.
Since it is at a higher position, it is still shut off at this point, and the voltage Va remains at a high value. When the side 19a reaches the optical axis 17a at t = t2, the optical axis 17a becomes conductive, and the output voltage Va falls. When the key press is completed, the keyboard swings in the reverse direction, the optical axis is cut off, and the output voltage Va,
Vb also rises again and returns to the original voltage value.

[0034] Then loosen the hex bolts 30, the shutter plate 13 as shown in FIG. 2 (c) after moving to the right in the figure, and tighten the hex bolts 30, in the state shown in FIG. 2 (a) The key is pressed at the same speed as when the key was pressed. Then, when the optical axis 17a is moved upward, the distance to reach the hypotenuse 19b is shorter than that in FIG. 2A, and the optical axis 17b is conducted at a time point t = t3 earlier than t = t1. Since the side 19a for conducting the other optical axis 17a is horizontal, even if the shutter plate 13 is moved horizontally as shown in FIG. 2 (a) to FIG. 2 (c), the distance to the optical axis 17a can be increased. Does not change. Therefore, the optical axis is the same as t in FIG.
= T2, conduction is achieved. When the key press is completed, the keyboard swings in the reverse direction and returns to the original position, and the output voltages Va and Vb also rise again and return to the original voltage values.
(D).

When the conditions other than the key pressing speed are the same, when the key pressing speed is increased, Va and V
The time difference between the falling of b (t2-t1 in FIG. 2B,
In FIG. 2D, since t2−t3) becomes shorter,
If the time difference increases as in (d), it is erroneously detected that the key pressing speed has decreased. Accordingly, if this principle is used, when the generated electronic sound is too loud compared to the key pressing speed, the volume can be reduced by moving the shutter plate 13 to the right as shown in FIG. 2C. Conversely, when the electronic sound is too low, the sound volume can be increased by moving the shutter plate 13 to the left as compared with FIG.

On the other hand, the generation timing of the electronic sound is determined by the predetermined time after the conduction of the optical axis 17a in the key pressing speed detecting device 1, that is, the optical axis which is later conducted out of the two optical axes as described above. Not changed because it occurs later. That is, the key pressing speed detection device 1 can adjust only the sound volume within a predetermined range without changing the generation timing of the electronic sound.

As another embodiment of the present invention, a key pressing speed detecting device 3 shown in FIG. 3 will be described. Key pressing speed detection device 3
The shutter plate 13 of the key pressing speed detecting device 1 shown in FIG.
3, the holding plate 35 is replaced with a plate supporting portion 37.
In FIG. 2, the width of the plate supporting portion 15 of the key pressing speed detecting device 1 of FIG. 1 is slightly reduced.

The photo-interrupter 39 is exactly the same as the photo-interrupter 11 of the key-depression speed detecting device 1 shown in FIG. 1, and is fixed to a printed circuit board, how the optical axis is blocked, key-depression, and the like. The same applies to the method of detecting the key pressing speed. As shown in FIG. 3A, the circular plate 31 is formed by forming a trapezoidal hole 41 and a long hole 43 in a circular plate-shaped member. The trapezoidal hole 41 is formed substantially at the center of the circular plate 31, and has a shape such that one long side of a rectangle is obliquely inclined. Hereinafter, this oblique side is referred to as a hypotenuse 41a, and the opposite side is referred to as a long side 41b.

On the other hand, the outer shape of the long hole 43 has a central angle of about 90 °.
The shape of the sector is made to coincide with the center of the circular plate 31, and the width of the hole is slightly larger than the diameter and diameter of the bolt 45. This long hole 4
3 is a long side 41 slightly inside the outer periphery of the circular plate 31.
It is open at the location facing b.

The support plate 33 is a substantially rectangular plate-like member, and has two insertion holes in the vicinity of one short side, which are opened in parallel with the short side. Is about 1/2 of the length. On the side opposite to this short side, wavy irregularities having substantially the same length as the tongue piece 21 are provided.
The direction of each ridge line and valley line is substantially parallel to the vertical direction of the keyboard 47.

The holding plate 35 is a rectangular parallelepiped member made of metal, and has one surface on which two tap holes for fastening the bolts 45 are formed.
The support plates 33 are spaced at the same intervals as the insertion holes of the support plate 33. As described above, the components of the key pressing speed detecting device 1 shown in FIG. 1 that replace the shutter plate 13 are arranged as shown in the perspective view of FIG. That is, two bolts 4
5 is passed through the insertion hole provided in the support plate 33 via the spring washer and the washer, and then passed through the long hole 43 of the circular plate 31 and fastened to the tap hole provided in the holding plate 35, thereby holding the support plate 33. The circular plate 31 is sandwiched between the plate 35 and the plate 35. At this time, the hypotenuse 41 of the circular plate
“a” is set so as to rise rightward when turned as shown in FIG.

The key-pressing speed detecting device 1 shown in FIG.
Similarly to the engagement between the shutter plate 13 and the tongue piece 21, the wavy irregularities of the support plate 33
7 and fastened to the concave portion 49 of the keyboard 47 with a hexagon bolt 51. Key pressing speed detecting device 3 configured as described above
In FIG. 3, when the relative position between the circular plate 31 and the photointerrupter 39 is as shown in FIGS. 3 (a), 4 (a) and 4 (c), the output voltage waveforms are as shown in FIGS. 3 (c) and 4 (b), respectively. ), As shown in FIG. However, in the waveform graph,
It is assumed that the vertical axis is voltage, the horizontal axis is time, and a key is pressed at time t = 0 on the horizontal axis. The voltage at the output terminal corresponding to the optical axis 53a is Va, and the voltage at the output terminal corresponding to the optical axis 53b is Vb.

That is, it is assumed that the key is pressed when the circular plate 31 is at the position as shown in FIG. 3A with respect to the photointerrupter 39, and a voltage waveform as shown in FIG. 3C is output. That is, when the key is pressed at t = 0,
7, the circular plate 31 starts to descend, and at time t = t1, the oblique side 41a reaches the optical axis 53b, the optical axis 53b is conducted, and the output voltage Vb falls. Since the hypotenuse 41a is a straight line that rises to the right in the figure, the optical axis 53a is still blocked at this point, and the voltage Va remains high. When the oblique side 41a reaches the optical axis 53a at t = t2, the optical axis 53a becomes conductive, and the output voltage Va falls. When the key press is completed, the keyboard swings in the reverse direction, the two optical axes are cut off, and the output voltages Va and Vb also rise again and return to the original voltage values.

Next, the two bolts 45 are loosened, and FIG.
After rotating the circular plate 31 in the counterclockwise direction as described above, the two bolts 45 are tightened and fixed, and the key is pressed at the same speed as in the state shown in FIG. Then
Since the distance from the optical axis 53b to the hypotenuse 41a is smaller than in the state of FIG. 3A, t = t4 earlier than t = t1.
At this point, the optical axis 53b is conducted. On the other hand, since the distance from the optical axis 53a to the hypotenuse 41a is large, t =
At time t = t5, which is later than t2, the optical axis 53a is turned on. When the key press is completed, the keyboard swings in the opposite direction, the two optical axes are cut off, and the output voltages Va and Vb also rise again and return to the original voltage values, so that the voltage waveform is as shown in FIG. Become like

That is, the time difference between the fall of the voltages Va and Vb becomes longer (from t2-t1 in FIG. 3C to FIG.
When (t5−t4 in (b)), it is erroneously detected that the key pressing speed has decreased. By using this principle, when the generated electronic sound is too loud compared to the key pressing speed, the volume can be reduced by rotating the circular plate 31 counterclockwise as shown in FIG. Conversely, when the electronic sound is too low, the circular plate 31 is shifted from the state shown in FIG.
By rotating clockwise, the volume can be increased.

In the case of the key pressing speed detecting device 3, since the fall of Va, which is a reference of the timing of generation of the electronic sound, is also delayed from t = t2 to t = t5, it is shown in FIG. Unlike the key pressing speed detection device 1, when the volume is adjusted, the generation timing also changes. Therefore, after the volume is adjusted, the generation timing is adjusted as necessary.

In the case where the timing of generation is improperly delayed by rotating the circular plate 31 as shown in FIG. 4A, the hexagonal bolt 51 is loosened, and
As shown in (c), the support plate 33 is replaced with the circular plate 3.
After moving to the right in the drawing with 1 fixed, the hexagon bolt 51 is tightened and fixed. Here, if the key is pressed at the same speed as when the key is pressed in the state of FIG. 4A, the distance from the optical axis 53a to the hypotenuse 41a becomes shorter than that of FIG.
At t = t7 earlier than = t5, the optical axis 53b is turned on. On the other hand, since the distance from the optical axis 53b to the hypotenuse 41a is also reduced by the same amount, the conduction timing of the optical axis 53b is also advanced from t = t4 to t = t6 by the same time as the advance of the conduction timing of the optical axis 53a. That is, the time difference between the falling of the voltages Va and Vb is the same as the state of FIG.

That is, in the key pressing speed detecting device 3,
When the support plate 33 is moved right and left with respect to the plate support portion 37, only the generation timing of the electronic sound can be adjusted without changing the volume. In addition, since the volume of the electronic sound can be adjusted by rotating the circular plate 31 with respect to the support plate 33 as described above, the volume is adjusted first, and then the generation timing is adjusted. Can be adjusted optimally.

In the key pressing speed detecting devices 1 and 3 described above, the volume of the electronic sound (or the volume and generation timing) is adjusted by using the shutter plate 13 (or the circular plate 31) by the photo interrupter 11 (or the photo interrupter 11). The movement can be performed by moving relative to the interrupter 39). This is not an irreversible process of shaving the shutter 63 as in the related art, and it is not necessary to remove the shutter plate 13 (or the circular plate 31).

In the above description, the conduction timing of the optical axis is described as being determined by the "distance" between the lower edge of the optical axis and the optical axis. When the keyboard swings around a fulcrum near the balance pin, the optical axis is determined by the angle of the "center angle" of the arc drawn on the shutter plate. Therefore, depending on the arrangement of the shutter plate and photointerrupter and the shape of the hole in the shutter plate, the "distance" and "center angle"
However, the two optical axes of the present embodiment are located substantially parallel to the longitudinal direction of the keyboard as shown in FIG. 6, and the distance between the two optical axes is large. Since the distance is sufficiently smaller than the distance from the balance pin to the optical axis, there is no problem even if the timing is determined by the distance from the optical axis to the lower edge of the hole.

Although the key pressing speed detecting devices 1 and 3 have been described above, the present invention is not limited to the above embodiment, but can be implemented in various modes. Key pressing speed detection device 1
By changing the shape of the pentagonal hole 19 of the shutter plate 13 described above, a key pressing speed detecting device having another effect can be obtained. For example, a trapezoidal hole 41 of the key pressing speed detecting device 3 may be used. With this configuration, a key pressing speed detection device that can adjust only the generation timing of the electronic sound is provided.

Similarly, the hypotenuse 19b of the hole 19 is shown in FIG.
It may be changed to a curve bulging downward as shown in FIG. In this case, even if the shutter plate 13 is slightly moved left and right, the distance from the optical axis 17b is only slightly changed, so that a key pressing speed detecting device capable of finely adjusting the volume can be provided.

Conversely, the hypotenuse 19b of the hole 19 is also shown in FIG.
If the curve bulges upward as shown in (b), the optical axis 17b can be obtained by slightly moving the shutter plate 13 left and right.
Since the distance to the key-pressing speed greatly changes, a key-depression speed detecting device having a wide variable range for volume adjustment can be provided.

In addition, the edge of the hole 19 may be formed into various curves, the shutter plate 13 (or the circular plate 31) may be moved not in a parallel manner but in a swinging manner like a pendulum, or a link mechanism may be provided. Alternatively, the shutter plate 13 may be moved along a predetermined curve.

In the key pressing speed detecting devices 1 and 3, the tongue 2
Although the wavy irregularities of the support plate 1 and the support plate 33 were rough and the resolution of the volume adjustment was low, the pitch of the irregularities was made finer as appropriate, so that the volume could be finely adjusted, or this irregularity was eliminated. Alternatively, it can be fixed at any position.

Of course, the shutter plate 13 (or the support plate 33) may be changed to another structure as a parallel movement mechanism. For example, a small ball screw is provided below the keyboard, and the position of the shutter plate 13 (or the support plate 33) provided with a nut engaged with the screw can be continuously changed.
A long hole is provided on the 3 (or support plate 33) side,
This may be fixed to the keyboard by inserting several bolts, and a simple configuration may be adopted in which the bolt is moved along the long hole.

The output voltage may rise when a key is pressed, and the key pressing speed may be measured.
FIG. 5C shows a shutter plate 51 (one example) used at this time. This is the shutter plate 51
The shapes of the lower edges 51a and 51b are similar to the shapes of the side 19a and the oblique side 19b of the key pressing speed detecting device 1, respectively. In a key-depressing speed detecting device using this shutter plate, in a non-key-depressed state, both optical axes are conductive, and when a key is depressed, the optical axes are turned left and right in the figure. Is shut off. In order to enable the key pressing speed detecting device 3 to be detected in the same manner, the trapezoidal hole 41 is not formed in the circular plate 31 and the portion below the oblique side 41a may be cut and removed.

As another configuration for detecting the rise,
The circuit configuration connected to the photointerrupter may be changed so that the output voltage rises when the optical axis is turned on. Further, in the present embodiment, the key pressing speed detection device has been treated as being applied to a piano that can select and play a stringing sound or an electronic sound.
The present invention can be applied to all keyboard instruments that change the volume or the like of generated electronic sounds.

[0059]

As described in detail above, claim 1 of the present invention
According to the key pressing speed detection device described in the above, since the shutter plate is supported by the plate supporting portion so as to be relatively movable with respect to the photo interrupter, by moving the shutter plate, the shutter The timing for conducting the two optical axes can be easily changed without removing the shutter plate.

That is, there are two distances between the optical axis and the lower edge of the hole in the shutter plate that blocks the optical axis. If the distance between the optical axes is reduced, the volume of the electronic sound increases. can do. By moving the optical axis so as to increase the distance between the portion that releases the interruption of the optical axis, which will be conducted later, and the optical axis, the timing of generation of the electronic sound can be delayed.

Further, since these adjustments are performed by a reversible operation of movement, if the movement is reversed, the opposite effect works, and the opposite effect can be obtained. In other words, it is easy to perform the adjustment again, for example, when the volume is excessively increased by the adjustment, the volume is decreased again, or when the timing is advanced too early, the volume is decreased again.

According to the key pressing speed detecting device of the present invention, the lower edges of the holes provided on the shutter plate are non-parallel straight lines whose edges release the interruption of the one optical axis. It has a shape having two portions, and furthermore, it can be moved in parallel with a linear portion closer to the keyboard at the lower edge of the shutter plate at the plate support portion. Only the volume of the electronic sound can be changed without changing the sound generation timing, and the volume can be easily adjusted.

That is, even when the parallel movement is performed, the linear portion closer to the keyboard is parallel to the direction of the movement, so that the distance from the optical axis of the photointerrupter does not change, and the timing of generation of the electronic sound is changed. Does not change. On the other hand, since the distant linear portion is not made parallel to the direction of this movement, the distance in the vertical direction to the optical axis of the photointerrupter becomes longer or shorter as the translation is made. The timing of the conduction of the optical axis, which has been interrupted, becomes later or earlier, respectively. In other words, 2
The volume of the electronic sound can be reduced by increasing the time difference between the conduction of the optical axes of the books, and the volume can be increased by shortening the time difference.

According to the third aspect of the present invention, the lower edge of the hole provided in the shutter plate is linear, and the plate supporting portion is parallel to a direction different from the straight line. Since the shutter is movable, the timing of the generation of the electronic sound can be changed without changing the volume of the electronic sound by moving the shutter plate in parallel, and the adjustment of the sound generation timing is easy.

That is, even if the parallel movement is performed, the inclination of the straight line does not change, so that the time difference between the conduction of the two optical axes of the photointerrupter does not change, that is, the volume of the electronic sound does not change. On the other hand, since the parallel movement is performed in a direction different from the above-mentioned straight line, the distance of the photointerrupter in the vertical direction from the optical axis becomes longer or shorter, so that the timing of the conduction of the optical axis, that is, the timing of generation of electronic sound. Can be slowed or fastened respectively.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a key pressing speed detecting device 1 according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing how a time difference detected when a shutter plate of the key pressing speed detecting device of FIG. 1 is moved left and right changes.

FIG. 3 is an explanatory diagram of a key pressing speed detection device 3 according to the embodiment of the present invention.

FIG. 4 shows a circular plate 31 of the key pressing speed detecting device of FIG.
FIG. 10 is an explanatory diagram showing a state in which the falling timing and the time difference change when is rotated, and only the timing detected when the support plate 33 is moved left and right changes.

FIG. 5 is an explanatory view showing another embodiment of the shutter plate of the key pressing speed detecting device 1 of FIG. 1;

FIG. 6 is an explanatory diagram showing a state in which the key pressing speed detecting device is attached to a piano.

FIG. 7 is an explanatory diagram in which a portion of a key pressing speed detecting device in FIG. 6 is enlarged.

[Explanation of symbols]

1,3 ... Key pressing speed detecting device 11,39
... Photo interrupter 13 ... Shutter plate 15, 37 ... Plate support 17a, 17b, 53a, 53b ... Optical axis 1
9 ... hole 21 ... tongue piece 27, 47 ... keyboard 3
1: Circular plate 33: Support plate 3
5: clamping plate 41: trapezoidal hole 43: long hole

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G10H 1/34 G10C 3/00

Claims (3)

(57) [Claims] 1. A photointerrupter arranged below a keyboard and having two optical axes running between a light emitting element and a light receiving element arranged substantially in parallel to a lower surface of the keyboard, and fixed to a lower part of the keyboard. A key-pressing speed detection device, comprising: a plate-like member that blocks the two optical axes together, and a shutter having a hole of a predetermined shape at a position that releases the blocking of each optical axis with a time lag when the keyboard is pressed. in the above shutter consists of a shutter plate having the hole, and the plate supporting portion for supporting the shutter plate is fixed directly to the keyboard, yet the shutter plate, to the upper Symbol photointerrupter, the plate supports A key-pressing speed detecting device, which is supported so as to be relatively movable by a key-pressing speed. 2. The key-pressing speed detecting device according to claim 1, wherein the number of the holes is one, and the lower edges of the holes are non-parallel to each other so as to release the interruption of the respective optical axes. The plate support portion movably supports the shutter plate in parallel with the straight portion closer to the keyboard among the two straight portions. Key pressing speed detection device. 3. The key-pressing speed detecting device according to claim 1, wherein the number of the holes is one, and the lower edge of the hole has a linear shape. A key-pressing speed detecting device, wherein the key-pressing speed detecting device is supported so as to be movable in a non-parallel to a straight line of a lower edge portion of the hole.