JPH0741038Y2 - Keyboard sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a keyboard sensor in an automatic playing piano, which detects a key movement by a photo coupler that outputs different signals based on a slit pattern of an encoder plate attached to a key. By forming 2 ^N slit patterns on the first encoder plate and arranging N photo couplers on the first encoder plate, the detection accuracy for the operation of the key as the keyboard sensor is improved.

(Prior Art) Conventionally, as an automatic playing piano of this kind, for example, one shown in FIG. 9 has been known.

In the figure, this automatic playing piano has a plurality of keys 101
A key mechanism 107 that drives a hammer 103 and a damper 105 based on the movement of the key 101, and a string 109 that is struck by the hammer 103.
Is built in. Then, the controller 113
Is a plurality of sensors 115 arranged on the orbit of the hammer 103,
It was connected to a solenoid 117 that applies a force to the key 101.

The automatic playing piano having such a structure functions in the recording mode and the reproducing mode, and in the recording mode, when the hammer 103 strikes the strings by the player's key operation, the movement of the hammer 103 is arranged on a plurality of sensors. The hammering force is detected by 115 and the rotational speed of the hammer 103 is calculated based on the detection result to estimate the string striking force of the hammer 103.

When the string striking force of the hammer 103 is estimated in this manner, the string striking force is held in the storage unit of the controller 113 together with key information for identifying the operated key 101 as string striking information, until the end of the performance. The above operation is repeated.

Next, when the automatic playing piano is set to the reproduction mode, the controller 113 identifies the key 101 to be driven based on the key information, and excites the solenoid 117 provided corresponding to the key 101 to activate the key 101. Apply a predetermined force to. At this time, the force applied from the solenoid 117 to the key 101 is the magnitude that causes the hammer 103 to generate a string-striking force represented by the string-striking information. A force is generated, and the same movement as in the recording mode is reproduced by the continuous movement of the hammer 103.

Therefore, in such a conventional automatic playing piano,
Since the movement speed of the hammer 103 was directly detected by the sensor 115 to form the information about the string striking force, it is determined from the position, size, etc. of the hammer 103 at the piano manufacturing stage in order to have an automatic performance function from the beginning. If the sensor 115 is arranged on the orbit, an automatic playing piano can be constructed with a slight increase in the number of steps.

However, when it is desired to add an automatic performance function to an already manufactured piano, the size of the key mechanism 107 and the hammer 103 of the piano, the mounting positions thereof, etc. are different for each manufacturer, and further, the same manufacturer is used. However, since these may differ depending on the type of piano, the trajectory of the hammer 103 is not uniform. Therefore, the hammer 103
When trying to mount the sensor 115 for detecting the movement speed of the, the position of the sensor 115 and its mounting method must be individually designed after confirming the mounting position of the hammer 103, its size, etc. There was a problem that a large amount of cost and a large-scale construction were required to make the piano an automatic performance device.

Here, in a keyboard instrument such as a piano, when a force is applied to the key 101 by pressing a key, the key 101 moves at a speed corresponding to the applied force, and the movement of the key 101 causes the movement of the key mechanism 107. The force applied to the key 101 is transmitted to the hammer 103.

Since the hammer 103 hits the strings in this manner, its striking force can be estimated by detecting the movement speed of the key 101. Moreover, the mounting structure of the key 101 is almost constant regardless of the manufacturer of the piano and the model of the piano. In particular, from the reed 119 to the reed 121 of the key 101
The support structure up to is a substantially constant structure in all keys 101. Therefore, it is possible to design the mounting position and the mounting structure of the sensor 115 in advance.

Therefore, the keyboard sensor 115 that detects the movement of the key 101 is
It is conceivable to arrange it as a sensor unit on the shelf plate 123 between the reed inside 119 and the reed front 121 of the keyboard reed.

However, in this case, the reed 119 and the reed 121
Since the space between and is narrow, the sensor unit itself must be thin and small.

However, as the conventional keyboard sensor 115, one encoder plate is attached to the key 101, and one plate is attached to this plate.
It is known that one slit pattern is formed.
A light emitting element and a light receiving element of a photocoupler are arranged on both sides of the encoder plate (shutter) so as to face each other. Therefore, in the conventional keyboard sensor 115 of this type, the passing speed of the shutter between two points is measured.

That is, since only one slit pattern is formed on one encoder plate, and only one photo coupler is provided corresponding to one encoder plate, the sensing accuracy is improved. In order to detect various movements of the key 101, such as a staccato and a deep pianissimo, it is necessary to arrange a plurality of pairs of encoder plates and photocouplers in the narrow space.

(Problems to be solved by the invention) However, in such a conventional keyboard sensor, as described above, only one photocoupler is provided for one encoder plate. As a keyboard sensor that must be installed in a narrow space, there is a problem that it is not suitable for increasing the sensing accuracy for the complicated movement of the key.

(Means for Solving Problems) Therefore, according to this invention, a key provided so as to be vertically swingable, a light-shielding member fixed to the key, and the light-shielding member are arranged so that they can appear and disappear in the optical path. A keyboard sensor that is provided with the first and second optical sensors that output different detection signals depending on whether the light blocking member blocks the light path or transmits the light. A first light transmitting portion provided corresponding to the first optical sensor and a second light transmitting portion provided corresponding to the second optical sensor; and the first light transmitting portion. Has first and second edge portions where the detection signal of the first optical sensor changes in response to the swing of the key, and the second light transmitting portion has an optical path of the first optical sensor. The detection signal of the second optical sensor may be different between when the first edge is present and when the second edge is present. Is provided
Furthermore, the above-mentioned problems are solved by providing a keyboard sensor having a counter that goes up or down according to the detection signal of the second optical sensor when the detection signal of the first optical sensor changes. That is the purpose.

(Operation) In the keyboard sensor according to the present invention, when the key swings, the light blocking member appears and disappears in the optical paths of the first and second optical sensors. Thereby, the optical paths of the first and second photosensors are transmitted by the first and second light transmitting portions. here,
When the translucent member moves in the predetermined direction, the first translucent portion passes through the first edge and reaches the optical path of the first photosensor. that time,
The detection signal of the second photosensor is in a predetermined state. on the other hand,
When the light blocking member moves in the direction opposite to the predetermined direction, the first light transmitting portion passes through the second edge portion and reaches the optical path of the first optical sensor. At that time, the detection signal of the second optical sensor is in a state different from the predetermined state. The counter counts up or down according to the detection signal of the second optical sensor when the detection signal of the first optical sensor changes, so the count result of the counter becomes a value corresponding to the position of the key, The speed of change of the result is a value corresponding to the speed of the key.

A photointerrupter, a photoreflector, or the like is applied as the first and second optical sensors.

(Premise of Embodiment) Next, a configuration that is a premise of this embodiment will be described based on the drawings.

1 to 3 show a first prerequisite example of the keyboard sensor of the automatic piano playing device according to the present invention.

In FIG. 1, reference numeral 1 denotes a shelf plate, and a key 7 is supported in a reed 3 of a keyboard reed on the shelf plate 1 via a balance key pin 5 so as to be vertically swingable. A key drive unit 13 is arranged in a flat space 11 defined below the key 7 and above the shelf 1 between the reed inside 3 and the front 9 of the reed.

As shown in detail in FIG. 2, the lock driving unit 13 has a U-shaped case 15 and a plurality of electromagnetic actuators 17 supported by the case 15. The electromagnetic actuator 17 moves (drives) the key 7 up and down via a swing lever 19.

That is, the swing lever 19 is supported by the case 15 so as to be vertically movable via the flange 21, and one end of the swing lever 19 is pushed up by the tip of the electromagnetic plunger of the electromagnetic actuator 17. The other end of the swing lever 19 is formed in a fork shape and engages with a horizontal piece 25 of a plate-like hook 23 protruding from the lower surface of the key 7 from above.

A sensor unit 27 is arranged in front of the lock driving unit 13 in this space 11.

The sensor unit 27 detects the vertical movement of the key 7 and outputs a detection signal to a control unit (CPU) (not shown).

The sensor unit 27 is configured such that an encoder plate (shutter) 29 continuously formed at the lower end of a hook 23 that is fixed to the lower surface of the key 7 and protrudes downward with respect to the optical paths of the pair of photocouplers 31 and 33. It is provided so that it can appear and disappear freely.
That is, as shown in FIG. 3, the encoder plate 29 has a pair of slit patterns (windows) 35 in the width direction thereof.
37 is vertically displaced and formed in steps. Corresponding to the positions of the different slit patterns 35, 37, the pair of photocouplers 31, 33 composed of a light emitting element and a light receiving element are arranged on both side surfaces of the slit 41 of the case 39. That is, one slit pattern (window) 35 passes through the optical path of one photocoupler 31, and the other slit pattern (window) 37 passes through the optical path of the other photocoupler 33.

That is, corresponding to each of the two photo couplers 31 and 33 (N = 2), the encoder plate 29 has 2 ² = 4 slit patterns 35 along its vertical direction (the moving direction of the key 7). , 37 are formed.

In the keyboard sensor having the above configuration, when the key 7 is lowered by the key depression operation, the shutter 29 is also lowered and the windows 35, 37 are moved.
Will cross the optical paths of the photocouplers 31 and 33, respectively. As a result, the optical paths of the photocouplers 31 and 33 are shuttered.
When it is blocked by 29, for example, an OFF signal is transmitted to windows 35 and 37.
When the light passes through and reaches the light receiving element, an ON signal is output.
Further, in the non-depressed state (when the key is released), the shutter 29 is at the upper limit position and blocks the optical paths of the photocouplers 31 and 33.

Then, according to the movement of the key 7, these photocouplers 31, 33
Will output four different types of signals as shown in the following table based on the slit patterns (windows) 35 and 37 as a whole.

In this attached table, the key 7 is located at the highest position at the fourth position and at the lowest position at the first position.

Then, based on the combination of these output signals, the controller calculates the position of the key 7 and the time (key pressing speed) required to move between the positions to determine the moving direction of the key 7. The speed and the touch thereof are detected. For example, it is possible to detect and determine whether the key 7 has risen or descended, or whether deep pianissimo, shallow touch, staccato, continuous strike at a shallow position, continuous strike at a deep position, or the like.

In the photocouplers 31 and 33, at least two light receiving sides are received, and the shutter 29 is provided with a gap necessary for resolution. Practically, it is 0.5 mm or more. The gap of the shutter 29 is provided with a step according to the resolution for each row, but when there is no step, a step is provided between the one photo coupler 31 and the other photo coupler 33.

4 and 5 show a second premise example of the keyboard sensor of the automatic playing piano according to the present invention.

As shown in these figures, in this premise example, three windows (slits) 53 of different sizes are arranged in the width direction of the encoder plate (shutter) 51 hanging from the key.
55 and 57 are installed side by side. These three windows 53, 5
5 and 57 have different height positions, and their windows 5
The widths of 3, 55 and 57 are the same, but the height itself is different in each row.

On the other hand, three photocouplers 61, 63 and 65 are fixed at predetermined positions corresponding to the respective rows of these windows 53, 55 and 57. That is, in each optical path of each photocoupler 61, 63, 65 consisting of a light receiving element and a light emitting element fixed to a predetermined portion, each window 53, 55,
57 is movably arranged.

Then, four windows 53 are arranged at equal intervals in the height direction of the encoder plate 51 (direction in which the plate 51 moves). window
Two 55 are arranged along the same direction, and one window 57 is arranged.
Has been formed. Therefore, these three rows of windows 53, 55, 57
Thus, eight different signals can be output to the encoder plate 51 along its height direction.

In other words, the keyboard sensor can detect 8 positions in the height direction of the key. With the encoder plate 51 having the above-mentioned slit pattern configuration, the height position of the key is set to the first position in correspondence with the vertical movement of the key.
It is possible to detect 8 positions from to 8th.

FIG. 5 shows a signal processing circuit for outputting a signal indicating the position of the key to the controller based on the output signal from each photocoupler.

That is, each output of each photocoupler 61, 63, 65 is input to the first to eighth AND circuits 71, 72, 73, 74, 75, 76, 77, 78 directly or via an inverter, and these AND The outputs of the circuits 71, 72, 73, 74, 75, 76, 77, 78 are the first to eighth flip-flop circuits 81, 82, 83, 84, 85, 86, 8 respectively.
It is input to each set terminal of 7, 88.

Then, the first to eighth flip-flop circuits 81, 82, 8
The reset terminals 3, 84, 85, 86, 87, 88 are respectively connected to the second to first AND circuits 72, 73, 74, 75, 76, 77,
Each output of 78 and 71 is input. That is, the output of the second AND circuit 72 is output to the reset terminal of the first flip-flop circuit 81, and the output of the third AND circuit 73 is output to the reset terminal of the second flip-flop circuit 82. To the reset terminal of the flip-flop circuit 83, the output of the fifth AND circuit 75 for the fourth flip-flop circuit 84, and the output of the sixth AND circuit 75 for the fifth flip-flop circuit 85. The output of the circuit 76, the output of the seventh AND circuit 77 to the sixth flip-flop circuit 86,
The seventh flip-flop circuit 87 includes an eighth AND circuit 78.
And the output of the first AND circuit 71 is input to the eighth flip-flop circuit 88, respectively.

In the second premise example having the above configuration, the case where N = 3 in the present invention is shown, and three windows 53, 55 and 57 are provided in a predetermined pattern (2) for three photocouplers 61, 63 and 65. ³ = 8 slit patterns) with 1 encoder plate 51
By forming the above, it is possible to detect eight positions with respect to the vertical movement of the key. The sensing accuracy as a keyboard sensor can be improved. The output of the eight combinations enables the controller to detect a key touch and the like more accurately.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS.

This embodiment is for two photocouplers (N = 2) as in the first precondition example.

In this embodiment, as shown in FIG. 6, one photo encoder plate 91 attached to the key has two photo couplers.
Corresponding to 92 and 93, two rows of windows 94 and 95 are formed alternately in the vertical direction at equal intervals. That is,
As shown, the window 94 is formed at the position corresponding to the lower edge of the window 95, whereas the window is not formed at the position corresponding to the upper edge of the window 95.

As shown in FIG. 7, signals are input from the photo couplers 92 and 93 to the count-up pulse generator 96 and the count-down pulse generator 97, respectively, and the counters are output from the generators 96 and 97, respectively. Signal is input to 98. The counter 98 converts into position information.

FIG. 8 shows the output waveforms of the photocouplers 92 and 93, the pulse generators 96 and 97, and the count value of the counter 98, respectively. In the figure, the key 7 is at the highest position first,
The count value of the counter 98 is "0". Further, since the optical paths of the photocouplers 92 and 93 are shielded by the lower end portion of the encoder plate 91, the output signals of these photocouplers are “0”. Here, when the key 7 is pressed, the optical path of the photocoupler 92 is first transmitted through the window 94,
The detection signal of the photocoupler 92 becomes "1". When the key 7 is further pressed, the lower edge of the window 95 reaches the photo coupler 98, and the detection signal of the photo coupler 93 rises to "1". Since the detection signal of the photocoupler 92 is "1" at this time point, a countdown pulse is generated by the countup pulse generator 96, and the count value of the counter 98 is incremented by "1" to become "1".

When the key 7 is further pressed, the upper edges of the windows 94 and 95 sequentially reach the optical paths of the photocouplers 92 and 93, so that the detection signals of these photocouplers 92 and 93 sequentially become "0". After that, similarly
When the key 7 is pushed down, the detection signal of the photocoupler 93 is "1" when the detection signal of the photocoupler 93 rises. Therefore, count-up pulses are sequentially output, and the count value of the counter 98 is shown in the figure. In this way, it is incremented to "2" and "3".

Next, when the key 7 is released after the optical path of the photocoupler 92 is made transparent by the window 94 at the fourth stage from the bottom, the encoder plate 91 moves upward and the third stage from the bottom. The upper edge of the window 95 reaches the optical path of the photocoupler 93. As a result, the detection signal of the photocoupler 93 rises to "1". However, at this point, the upper edge of the window 94 at the third stage from the bottom has not reached the optical path of the photocoupler 92 yet. Therefore, the countdown pulse is output from the countdown pulse generator 97,
As a result, the count value of the counter 98 is decremented to "2".

Thus, in this embodiment, the count value of the counter 98 represents the position of the encoder plate 91, that is, the key pressing depth of the key 7. The speed at which the count value changes corresponds to the key pressing speed (or key releasing speed) of the key 7.

In the third embodiment, since the number of slits (windows) in the encoder plate 91 is fixed, when the count value of the counter 98 exceeds the fixed range, the count value should be corrected to the boundary value. This makes it possible to correct an error caused by an error when the power is turned on and the reset circuit is unnecessary. The reset circuit becomes unnecessary due to the overflow or underflow of the counter.

(Effect) As described above, according to the present invention, the detection signal of the second optical sensor is detected when the optical path of the first optical sensor is at the first edge and when it is at the second edge. Therefore, the moving direction of the key can be accurately detected. In addition, since the counter is incremented or decremented according to the result, it becomes possible to perform accurate sensing for a complicated movement of the key.

[Brief description of drawings]

FIG. 1 is a side view showing a first premise example of a keyboard sensor of an automatic playing piano according to the present invention, FIG. 2 is an exploded perspective view showing a sensor unit according to the first premise example of the present invention, and FIG. Is a front view showing an encoder plate according to a first premise example, FIG. 4 is a front view showing an encoder plate according to a second premise example of the present invention, and FIG. 5 shows an encoder circuit according to a second premise example. FIG. 6 is a front view showing an encoder plate according to one embodiment of the present invention, FIG. 7 is a block diagram showing a signal processing circuit according to one embodiment, and FIG. 8 is a signal according to one embodiment. FIG. 9 is a side view showing a key driving unit of a conventional automatic playing piano. 7 ... key, 27 ... sensor unit, 29 ... encoder plate, 31,33 ... photocoupler, 35,37 ... window (slit pattern), 92,93 ... photocoupler (first and second
Optical sensor), 94, 95 ... Window (first and second light transmitting portions), 96 ... Count-up pulse generator, 97 ... Count-down pulse generator, 98 ... Counter.

Claims (1)

[Scope of utility model registration request] 1. A key provided so as to be swingable in a vertical direction, a light-shielding member fixed to the key, the light-shielding member being arranged so as to be retractable in and out of the optical path, and the light-shielding member being in the optical path. And a second optical sensor that outputs different detection signals depending on whether the light is blocked or transmitted, wherein the light blocking member is provided corresponding to the first optical sensor. A first light-transmitting portion and a second light-transmitting portion provided corresponding to the second optical sensor, wherein the first light-transmitting portion is the first light-transmitting portion in response to rocking of a key. The first and second edges where the detection signal of the optical sensor of the first optical sensor changes, and the second light transmitting portion is provided when the optical path of the first optical sensor is at the first edge and It is provided so that the detection signal of the second optical sensor is different from that at the edge of the second optical sensor. Keyboard sensors with up or counter for down in response to the detection signal of the second light sensor when the detection signal of the capacitors is changed.