JPH04367820A - Multiple optical path optical system and touch and touch response device of electronic musical instrument using the same - Google Patents

Abstract

PURPOSE:To handle optical signals which have uniform characteristics over many channels by providing an optical means which couples plural optical waveguide means optically with a single optical waveguide means through a couple of polarizing means. CONSTITUTION:Many optical fibers 6 are inserted into optical fiber holes 44 formed in a fiber coupling substrate 41 and coupled. The fiber coupling substrate 41 is coupled with an optical switch substrate 42 formed of lithium niobate, etc., and switched light is projected from the other surface of the optical switch substrate 42. This light is reflected by the reflecting surface of a lens member 43 where a metallic thin film of aluminum, silver, etc., with a high reflection factor is formed and then made incident on the single optical waveguide 10 arranged in the center of the fiber group. The reflection relation between the optical fiber 6 and single optical waveguide 10 on the reflecting surface of the lens member 43 can be set above a critical angle by arranging the optical fibers 6 other than the single waveguide 10 except at the center part, and the metallic thin film need can not be formed when this device is used as an optical multiplexer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the handling of a plurality of optical signals, and more particularly to a multi-optical path optical system that can adjust the characteristics of optical signals divided into a plurality of groups, and a touch response device for an electronic musical instrument using the same.

0002

2. Description of the Related Art In recent years, various techniques for transmitting and processing signals as optical signals have been developed.

For example, Japanese Patent Laid-Open No. 1-134431 discloses a method for time-divisionally switching optical signals.
A configuration in which an optical signal input from one optical fiber is branched by a spatial optical switch, stored in each optical memory channel such as a bistable semiconductor laser, and an output signal from the optical memory is selectively read out by the spatial optical switch. The spatial optical switch is configured with a bistable semiconductor laser, and the optical signal input from one optical fiber is branched to multiple optical fibers, and the branched light is selectively transmitted for each channel using the cascade-connected bistable semiconductor lasers. This disclosure discloses a configuration in which the information is stored, selectively read out for each channel, read out to a plurality of optical fibers connected to the plurality of channels, and these optical fibers are coupled to obtain output light from one optical fiber.

[0004] Furthermore, Japanese Patent Application Laid-open No. 2-46431 discloses
The output light of the lens array arranged dimensionally is
In this configuration, a polarizer is inserted between the optical switch and each lens array, and the switched optical signals are received by a lens array and outputted. A configuration is disclosed in which output light is obtained by rotating the polarization axis in a switch.

The above are examples of general optical communication or optical signal processing. Currently, electronic keyboard instruments such as electronic pianos and keyboard synthesizers are widely put into practical use. The keyboard of this type of electronic keyboard instrument generally has an on/off switch for each key.
A switch for detecting off and a sensor for detecting keystroke strength (initial strength) are provided. By detecting the turned-on key, the pitch is determined, and by detecting the initial strength, the pronunciation level and level displacement characteristics (
envelope), etc. In some electronic keyboard instruments, the pressing strength during key-on (
Some devices detect aftertouch (aftertouch) and control effects such as the sound level and vibrato.

By the way, in the actual performance by a keyboard player, not only during the key-on, but also before the key-on and after the key-off, the attack (startup of a musical note) occurs naturally.
It often expresses a release (lingering sound), and by reflecting these finger movements in musical sounds, it is possible to generate expressive musical sounds. However, with conventional keyboards, it is possible to detect key on/off, the initial strength at key-on, and aftertouch during key-on and reflect it in the musical sound, but the contact state between the fingers and the keyboard before key-on and after key-off is could not be detected.

[0007] Actual piano (acoustic piano)
The tone produced when a key is struck is not simply determined by the strength and speed of the keystroke, but also changes subtly depending on how the key is struck and how the finger is released from the key. For example, there are two types of performance where you press a key with your finger on the key (i.e., the key is suddenly accelerated from an initial velocity of 0) and one where you press the key with your finger dropped from above the key (i.e., the key is suddenly accelerated from the initial speed of 0). (moves at an almost constant fast speed until the key is pressed)
Even if the keystroke strength is the same, the tone will be different. Also, the tonal lingering effect is different depending on whether you turn off the key that was on quietly or when you turn it off in a popping manner. The reason for this is the effect of the damper, which suppresses the vibrations of the strings. For example, when you gradually release the key, the damper begins to come into contact with the vibrating strings, and the tone changes accordingly. When you completely release your hand, the vibration of the string is completely suppressed and the sound is silenced. Therefore, depending on the key release method, the timbre lingering changes continuously until the sound is muted.

In order to realize such musical tones in electronic musical instruments, the entire movement of the keys, especially the information from the moment the key is touched (initial speed of the key) to the moment the key is pressed all the way, is monitored to control the musical tone. An attempt was made to reflect this. For example, Japanese Patent Laid-Open No. 2-214897 proposes an all-sensing keyboard that monitors all key press operations. This technology is an excellent technology that matches digital technology, but the configuration is complicated and manufacturing costs are high.

On the other hand, various proposals have been made for electronic musical instruments to control musical tones using light.

For example, Japanese Utility Model Application Publication No. 57-9998 discloses that a reflective member is connected to the foot keyboard of an electronic organ, and light emitted from a reflective photocoupler is reflected by the foot keyboard operated by the player and is transmitted to the light receiver of the photocoupler. A configuration in which light is received is disclosed.

Japanese Patent Laid-Open No. 2-33196 discloses a configuration in which an optical shutter is coupled to each key of a keyboard, and a plurality of photocouplers whose optical paths are interrupted or conducted by key press operations are provided. They were put into pairs and each emitted light when current was passed in different directions.
Discloses a configuration that reduces the number of wiring lines.

[0012] Japanese Patent Publication No. 58-9959 discloses that a musical tone signal is emitted as an optical signal from a plurality of light emitting elements, and is made to face an optical fiber via an optical shutter having an aperture window, and the optical shutter is emitted in response to the operation of a key. This disclosure discloses a configuration in which the musical tone envelope is controlled by displacing the musical tone envelope and receiving the transmitted light by one light receiving element via an optical fiber.

[0013] Japanese Utility Model Publication No. 59-194796 discloses that shutters connected to a plurality of keys are arranged in an optical matrix, a light emitting port and a light receiving port are opposed to each other through the shutters, and light is emitted from a plurality of light emitting elements. discloses a configuration of a key assigner that introduces light from the column direction of a matrix to each light emitting port, and receives the light received by the light receiving port by a plurality of light receiving elements via a plurality of optical fibers arranged in the row direction. There is.

JP-A-62-153999 discloses that light emitted from a plurality of light emitting elements is coupled to a plurality of optical fibers via a light blocking plate coupled to a plurality of keys, and each optical fiber is connected to one optical fiber.
The disclosure discloses a configuration in which the light is received by a single light-receiving element.

JP-A-1-147508 discloses a configuration in which light emitted from a single optical fiber is distributed to a plurality of optical fibers via a transmission type or reflection type hologram.

[0016] Japanese Patent Application Laid-Open No. 2-68599 discloses that a wind instrument, which is a monophonic instrument that generates a single note at a time, is provided with a photoreflector that is displaced in accordance with breath pressure, and light is emitted from a light emitting diode to this photoreflector. However, a technique is disclosed in which reflected light is received by a phototransistor to obtain a monitor signal corresponding to breath pressure.

On the other hand, in keyboard instruments such as pianos,
Touch sensitivity differs depending on the type of white keys and black keys, the areas of keys near and far away, or the type of keyboard, such as a keyboard or a foot keyboard. Skilled players take these differences in touch sensitivity into account when playing.

[0018]

Problems to be Solved by the Invention In a photocoupler type sensor that combines a light emitting element and a light receiving element, the overall characteristics are the product of the characteristics of each component. For this reason, when using a plurality of photocoupler type sensors, it is extremely difficult to make their characteristics uniform. When analog signals are processed via a photocoupler type sensor, variation in characteristics becomes a major problem.

For example, when detecting the touch of a key operation in a keyboard-type electronic musical instrument, if a photocoupler type sensor is provided for each key, not only will the manufacturing cost increase due to the increase in the number of parts, but it will also be difficult to make the characteristics uniform. It is extremely difficult to arrange. This makes highly accurate touch detection extremely difficult.

Furthermore, in an electronic keyboard instrument, it is preferable that when the performers play with the same intention, the musical tones will have virtually the same effect. For example, a touch response device is desired in which the touch sensitivity within the key range is uniform and the difference in touch sensitivity can be set between the key ranges.

An object of the present invention is to provide a multi-optical optical system that divides a large number of channels into a plurality of groups, handles optical signals with uniform characteristics within each group, and can set differences in characteristics between the groups. It is.

Another object of the present invention is to provide a touch response device for an electronic musical instrument that can divide a large number of keys into a plurality of groups and adjust the touch sensitivity for each group.

[0023]

[Means for Solving the Problems] A multi-path optical system of the present invention includes a plurality of first optical waveguide means, optically coupled with the plurality of first optical waveguide means, and a two-dimensional optical system on a single substrate. a plurality of polarization changing means arranged to change the polarization state of incident light, and a pair of polarization means arranged sandwiching the polarization changing means, at least one of which is divided into a plurality of regions, and each region a pair of polarizing means having different polarization axes;
Regarding the pair of polarizing means, a single second optical waveguide means disposed on the opposite side from the first optical waveguide means, and the plurality of first optical waveguide means and the single second optical waveguide means. It has an optical system that optically couples the pair of polarizing means and the plurality of polarization changing means.

Further, the touch response device for an electronic musical instrument of the present invention is optically coupled to the multi-optical optical system according to claim 1 and each of the plurality of first optical waveguide means, and has an optical input port and an optical a plurality of light amount changing means including an output port and a changing means for changing the amount of light directed from the optical input port to the optical output port; a keyboard means having a plurality of keys corresponding to the plurality of light amount changing means; and an actuator that drives a corresponding change means of the light amount change means in response to a key press operation.

[0025]

[Operation] Light that enters the polarization changing means from the first optical waveguide via one of the polarizing means undergoes a predetermined polarization state change. This light is guided to the second optical waveguide via the other polarizing means. At least one of the pair of polarization means is divided into a plurality of regions, and each region has a different polarization axis direction, so even if the polarization changing means undergoes a certain change, the light output to be analyzed will differ from region to region. It turns out.

In this way, a multi-light path optical system is formed in which differences in characteristics can be set for each region.

By applying such a multi-light path optical system to a touch response device for an electronic musical instrument, a touch response device for an electronic musical instrument that can divide a large number of keys into a plurality of groups and adjust the touch sensitivity for each group can be provided. be done.

For example, the key touch detection signal can be used to control various effects such as volume, tone, vibrato depth or speed, tremolo depth or speed, reverb depth, PAN control, chorus effect control, etc. used.

[0029]

Embodiments will be explained below with reference to the drawings.

FIG. 1 is a block diagram showing the entire system. In the figure, a single light source 1 formed of an LED or the like
The light emitted from the optical fiber is divided into a large number of light beams, for example, 64 light beams, by the optical distributor 2 and supplied to the input optical fiber 3. Such an optical distributor 2 can be realized by a configuration in which a large number of optical fibers are bundled at one end. Each input side optical fiber 3 is coupled to a light amount changing device 4 such as a keyboard stroke sensor, and the output light of the light amount changing device 4 is supplied to an optical multiplexer 8 via an output side optical fiber 6. For example, as each key on a keyboard is depressed, the corresponding stroke sensor provides a light output that increases in response to the key depression. The optical multiplexer 8 is connected to a sequential pulse generation circuit 9.
The optical signals supplied from a large number of output side optical fibers 6 are multiplexed by time division and supplied to a single optical waveguide 10. A multiplexed optical signal carried by a single optical waveguide 10 is converted into an electrical signal by a single light receiving element 11 formed of a phototransistor, a photodiode, etc., and converted into a digital signal by an analog-to-digital converter 12. converted.

The signal S1 representing the multiplexed light amount change data is directly supplied to the A terminal of the subtraction circuit 14, while
The signal is supplied to the B terminal of the subtraction circuit 14 via the time division delay circuit 13. The time division delay circuit 13 has a delay time of approximately 3 to 20 msec.
, giving a delay time of about 3 msec, for example. The subtraction circuit 14 generates a signal as an output signal by subtracting the signal S1d supplied to the B terminal from the signal S1 supplied to the A terminal, and supplies it to the utilization device 15.

In the above configuration, the multiplexed signals are processed in a time-division manner. For example, the light amount data changed by the 64 light amount changing devices 4 is sequentially processed by time division delay circuit 13, subtraction circuit 14, etc. by time division.

The comparison circuit 16 receives the multiplexed optical signal S at the A terminal.
1, and a threshold L1 for key-on determination is received from the first threshold generation circuit 17 at the B terminal. When the stroke sensor 4 moves slightly due to the key press and the value of the multiplexed optical signal S1 becomes larger than the threshold L1, key-on is determined and a keying signal KING is generated.

Further, the comparison circuit 18 receives the multiplexed optical signal S1 at its A terminal, and receives the key-off determination threshold L2 from the second threshold generation circuit 19 at its B terminal. When the key is released, the signal from the stroke sensor 4 becomes smaller, and the optical signal S1 reaches the threshold L.
When the value becomes smaller than 2, it is determined that the key is off, and a key off signal KOF is generated. These keying signals KI
The NG and key-off signal KOF are supplied to a time-division differentiation circuit 21, which generates one key-on pulse KOP indicating the start of a key-press operation for each key-press operation. The time division timer counter 22 receives the key-on pulse KOP from the time division differentiation circuit 21 and generates continuous pulse signals φ- and φe at regular intervals, for example, every 3 msec. clock signal φ
e, together with the keying signal KING, drives the time division delay circuit 13 at fixed delay time intervals to give a fixed delay time to the signal S1 to form the delayed signal S1d.

The comparison circuit 23 connects the multiplexed optical signal S to the A terminal.
1, the delayed optical signal S1d is received at the B terminal, and the optical signal S
1 is larger than the delayed optical signal S1d, an output is generated. That is, since the optical signal S1 monotonically increases while the key is being depressed, A>B, and an output is generated until the key depression operation stops. The AND circuit 25 is the comparator circuit 23
and the output of the time division timer counter 22, and when the selection means 26 such as a switch is selected to the a side, an output signal is given to the enable terminal EN of the subtraction circuit 14, and during the key press operation, the subtraction is performed. Activate circuit 14. Also,
When the selection means 26 is selected to the b side, the φ- signal of the counter 22 is sent to the enable terminal EN of the subtraction circuit 14.
and activates the subtraction circuit 14 during the key press operation.

In the sequential pulse generation circuit 9, an oscillation circuit 31 generates a clock signal φs at a constant frequency,
The counter circuit 32 counts this clock signal and
For example, a signal for sequentially selecting 64 output optical fibers 6 is generated. The bit conversion circuit 33 is the counter circuit 3
The optical multiplexer 8 receives m (for example, 64) bit signals for selecting each output optical fiber 6 as pulses.

In addition to the optical fiber bundle, the optical distributor 2 can also be composed of an optical demultiplexer having the same configuration as the optical multiplexer 8. Furthermore, an optical multiplexer or demultiplexer uses a hologram as disclosed in JP-A No. 1-147508 to split a single beam into multiple beams or combine multiple beams into a single beam. It can also be composed of things.

FIG. 2 shows an example of the structure of the optical multiplexer 8. FIG. 2(A) shows a cross-sectional structure, and FIG. 2(B) shows an exploded view thereof.

As shown in FIG. 2(A), a large number of optical fibers 6 are inserted into optical fiber holes 44 provided in a fiber coupling board 41 and coupled. The fiber-coupled substrate 41 is coupled to an optical switch substrate 42 made of lithium niobate, LiNbO3, etc., and the switched light is emitted from the other surface of the optical switch substrate 42. This light is reflected by the reflective surface of the lens member 43 formed with a thin metal film of aluminum, silver, or the like with high reflectivity, and is incident on the single light guide path 10 arranged at the center of the fiber group. Note that this single light guide path 10 can also be formed by an optical fiber. Further, the reflective surface of the lens member 43 is arranged so that the optical fibers 6 other than the single light guide path 10 are arranged avoiding the center, so that the reflection relationship between the optical fiber 6 and the single light guide path 10 is adjusted to a critical angle. It is also possible to set more than that. In this case, total internal reflection can be used, so when using FIG. 2 as an optical multiplexer, the metal thin film can be made unnecessary. When using Figure 2 as an optical multiplexer,
Since the light is only partially attenuated by escaping from the central part where no total reflection occurs, if the light that is slightly stronger than the escaping light is input from the single light guide path 10, the metal thin film is not required in this case as well. be able to.

Fiber coupling board 41, optical switch board 4
2. The lens member 43 is assembled by aligning its position using the alignment marker 45, as shown in FIG. 2(B). Note that the alignment marker 45 is configured by forming a convex portion on one member and a concave portion on the surface facing the convex portion. A large number of optical switches 49 are formed on the optical switch board 42 on the entrance side, as will be described later.

FIG. 3 shows the configuration of an optical coupling section between a fiber or optical waveguide and other members. FIG. 3(A) schematically shows the coupling between the output side optical fiber 6 and the optical switch board 42. A large number of optical fiber holes 44 are formed in the fiber coupling board 41, and the optical fiber 6 is inserted into each optical fiber hole 44. At this time, a lens 46 is inserted into the tip of the optical fiber 6, and the dispersed light emitted from the optical fiber 6 is shaped into a parallel light beam and is made to enter the optical switch board 42.

FIG. 3B shows a coupling portion of a single optical waveguide located in the center. A single optical waveguide 10 is inserted into an optical fiber hole 44 that passes through a fiber coupling board 41 and an optical switch board 42. A lens 46 is also inserted at the tip of this optical waveguide 10. Furthermore, the surface of the lens member 43 facing the lens 46 is processed into a spherical shape. That is, considering the case of light traveling to the right from the optical waveguide 10, the dispersed light emitted from the optical waveguide 10 is
The light formed by the lens 46 and the lens member 43 becomes diffused light that is diffused at a predetermined angle and is emitted to the right side. Note that when the optical waveguide 10 receives light emitted from each fiber 6, each light component travels backwards along the same optical path.

The lens 46 used in conjunction with each optical fiber or optical waveguide can be a spherical lens made in advance, but it can also be made during the assembly process as described below.

In FIG. 3C, the optical fiber 6 is inserted into the fiber hole 44 of the fiber coupling board 41, and a predetermined amount of transparent resin or the like is dropped from the upper opening and hardened to form the lens 46.
Indicates when to create. In this case, it is necessary that the tip of each optical fiber 6 is directed upward. It is desirable that the transparent resin has a refractive index approximately equal to that of the optical fiber.

FIG. 3(D) shows the fiber coupling substrate 41
The fiber hole 44 is coated with a transparent resin or the like, and the optical fiber 6 is inserted, the transparent resin is scraped off, and the lens body 46 is sent out to the distal end. Figure 3 (
The lens 46 can be created by either method C) or (D).

FIG. 4 shows an example of the structure of the optical switch board. FIG. 4(A) shows a perspective view, and FIG. 4(B) shows a sectional view.

The optical switch board 42 is made of LiNbO3 or the like, and has a large number of optical switches arranged in a two-dimensional matrix. The cross-sectional view in FIG. 4(B) shows an enlarged portion of one optical switch. A concave portion is selectively formed on the surface of the optical switch board 42, and the surface of the concave portion is about 4 mm from the surface.
It is shaped to form a 5 degree angle. A thin metal film of aluminum, silver, or the like having a high reflectance is formed on this slope, and a first mirror M1 and a second mirror M2 are formed. In addition, an optical waveguide OG formed of a transparent material with a high refractive index is provided on the surface portion sandwiched between the first mirror M1 and the second mirror M2.
is formed. An electrode 49a is formed on the surface of the optical waveguide OG so that a voltage can be applied to the optical waveguide OG. The wiring 48 for each electrode 49a is provided using the wiring area between the optical switches, as shown in FIG. 4(A). In each optical switch, the optical waveguide OG selectively transmits the incident light to the output side depending on whether or not a voltage is applied to the electrode 49a.

As shown in FIG. 4(B), the incident light is perpendicularly incident on the surface of the optical switch substrate 42, reflected by the first mirror M1, and incident on the optical waveguide OG, and then passes through the electrode 49a.
is selectively transmitted to the output side by the voltage applied to the
The optical switch board 4 is reflected by the second mirror M2.
2 and exits from the back side. Note that the optical switch may be of a phase control type, a directional coupling type, a refractive index distribution type, or the like. This optical switch is used to convert multiple optical signals into one multiplexed optical signal by turning incident light on and off.

The light amount conversion device 4 shown in FIG. 1 is, for example, a touch detection device for a keyboard of an electronic musical instrument. Figure 5 shows
An example of the configuration of a touch detection keyboard including such a touch detection device will be shown.

The plurality of white keys 52 and the plurality of black keys 53 are rotatably supported by a fulcrum portion 54 having a partially circular cross section and fixedly held at the rear of the key support member 50. A hammer 61 is provided under each key, and when the key is pressed down, the hammer 61 is driven, and an actuator 57 made of rubber or the like provided by outsert processing on the hammer side is driven, and the stroke described below is driven. Sensor 59 is activated. A return spring 55 is clamped in the vicinity of the key fulcrum of the hammer 61 and the key 52 in an overbridge manner to hold the hammer and the key in a predetermined position. A stroke sensor 5 is placed below the proximal end of the hammer 61 on a base member 58 such as a printed circuit board.
9 is placed. The stroke sensor 59 can be used for one octave, half an octave, two octaves, common to all keys, etc.
A plurality of pieces are collectively fixed to the same base member 58. The arrangement of the stroke sensor 59 on the keyboard is not limited to the configuration shown in FIG. 5, but can also be applied to the keyboard disclosed in Japanese Patent Application Laid-Open No. 1-229297. In other words, by adopting a structure in which the hammer drive from the key in Fig. 5 is reversely driven so that the center of gravity of the hammer moves upward when the key is pressed, the rotation fulcrum of the hammer moves to the lower part of the hammer on the side opposite to the center of gravity of the hammer. The stroke sensor 59 may be disposed at.

[0051] In the above, the stroke sensor 59
Although the pressing is performed by pressing down the hammer, it may be arranged in the space above the free end of the hammer in FIG. 5 and the stroke sensor 59 can be pressed down directly by the actuator section of the key. Furthermore, in a configuration in which the hammer is omitted, the stroke sensor 59 may be directly pressed down by the actuator portion of the key.

Here, an example of the structure of a stroke sensor is shown in FIG.
Shown below. FIG. 6(A) shows the overall cross-sectional view, and FIG. 6(B)
shows a partial perspective view.

In FIG. 6(A), the stroke sensor 5
The housing 61 of 9 is made of rubber or the like, and is deformed by applying force from above. Two optical fibers 65 and 66 are introduced from below into the base member 58 to which the housing 61 is attached, and are coupled to the optical coupling member 64. The optical coupling member 64 includes lenses 68 and 69 coupled to optical fibers 65 and 66, as shown in FIG. 6(B). The light emitted from the optical fiber 65 is focused by a lens 68 or projected onto the inner upper surface 62 of the housing 61 while preventing divergence, and the reflected light is introduced into the optical fiber 66 by a lens 69. lens 6
8 and 69 are set so that the amount of light transmitted is the largest when the key on the keyboard is pressed all the way down. In addition, the reflective surface 6
2 is a white reflective surface and is desirably mirror-finished.

The stroke sensor can have various configurations in addition to the one shown in FIG. However, Figure 6
As shown in the configuration shown in FIG.
It is preferable to completely surround the space through which light exits and enters, thereby achieving both a light shielding effect from the outside world and a dustproof effect.

In this way, in the case of the keyboard touch detection device, the light emitted from the single light source 1 is divided by the light splitter 2 into light beams corresponding to a plurality of keys, and is sent to the stroke sensor via the optical fiber 3. 4, and is supplied as an optical signal representing a key press operation from an optical fiber 6 to an optical multiplexer 8 (see FIG. 1).

FIG. 7 shows an example of the configuration of a time division delay circuit. The multiplexed optical signal S1 converted into an electrical signal is sent to the selector 7
1, and its output terminal is connected to the AND gate 72. The output of AND gate 72 is supplied to shift register 73. The shift register 73 is
The multiplicity of the multiplexed optical signal S1 (in the case of the above-mentioned touch keyboard,
The number of stages is equal to the number of keys. That is, the shift register stores one scan worth of multiplexed optical signals. Note that signals for n scans may be accumulated (n: an integer).

If the shift register 73 is a one-scan memory, the output signal of the shift register 73 forms a delayed optical signal S1d obtained by delaying the input signal S1 by one scan. This delayed optical signal S1d is “0” of the selector 71.
Supplied to the terminal. This selector 71 has a control signal C1 (keying
) is supplied. The control signal C1 (keying) is applied during the key depression period, selects the multiplexed optical signal S1, and supplies it to the AND gate 72. The AND gate 72 is applied with the multiplexed optical signal and an inverted signal of the key-off signal KOF. That is, when key release is detected, the key-off signal K
OF becomes 1, an inverted signal (0) is applied to AND gate 72, and the input of shift register 73 becomes 0.

The shift register 73 accumulates signals for one scan of the time division multiplexed signal, gives each signal a delay of one scan, and outputs the signal. Therefore, the multiplexed optical signal S1
and the delayed multiplexed optical signal S1d have a time difference of exactly one scan, and signals for the same key are outputted correspondingly. Therefore, the subtraction circuit 14 shown in FIG. 1 receives the current position signal for the same key and the position signal one scan ago, and outputs the difference between them. The time difference between the two inputs is constant,
Since the two inputs each indicate a position, the difference signal generated by subtraction is proportional to the key pressing speed.

FIG. 8 shows an example of the configuration of a time division differential circuit. FIG. 8(A) shows a block diagram of the circuit, and FIG. 8(B) shows signal waveforms of the main parts thereof.

As shown in FIG. 8(A), the time-division differentiator circuit 21 has a keying signal KING and a key-off signal KOF.
is input, and a key-on pulse KOP is output. The waveform of the keying signal KING is shown in the first row of FIG. 8(B).

When a certain key is pressed, a keying signal appears at a corresponding position within one scan in response to the key pressing operation. This keying signal appears repeatedly each time the scan is repeated (P1, P2, P3, . . . ). The keying signal KING is supplied to a shift register 76 through an OR circuit 75. The shift register 76 has, for example, the number of stages for one scan, and generates the delayed keying signal KINGd by providing a delay time for one scan. This delayed keying signal is shown in the second row of FIG. 8(B).

The first pulse P1 is delayed by one scan and a delayed pulse Pd is generated at a time position corresponding to the second pulse P2.
It appears as 1. Thereafter, the keying signal pulses are similarly delayed by one scan. The output of the shift register 76 is inverted by the inverter 77, and the output is shown in FIG. 8(B).
An inverted signal shown in the third stage is formed. The product of this inverted signal and the original keying signal KING is formed by the AND circuit 78, and the key-on pulse KO shown in the bottom row of FIG. 8(B) is generated.
Output as P. As is clear from the first and third waveforms in FIG. 8(B), this product signal is generated by the first pulse P.
It takes a value of "1" only at the 1 position.

Note that the output of the shift register 76 is fed back to the OR circuit 75 via an AND circuit 80. The other input terminal of the AND circuit 80 receives a signal obtained by inverting the key-off signal KOF by the inverter 79. While the key-off signal KOF is not output, the output of the inverter 79 is 1.
Therefore, the output of the shift register 76 is fed back to the input side of the shift register 76 via the OR circuit 75. Therefore, the shift register 76 continues to supply output while the key is being pressed.

FIG. 9 shows an example of the configuration of a time division timer counter. FIG. 9(A) is a block diagram showing the circuit configuration, and FIGS. 9(B) to (D) show signal waveforms in the main parts of the circuit in FIG. 9(A).

In FIG. 9A, the adder circuit 82 receives an input from the shift register 84 and an increment generator circuit 8.
1 and the unit amount "1" supplied from 1, and the sum is supplied to the AND gate 83. AND gate 83 supplies the sum signal from adder circuit 82 to shift register 84 while other inputs are present. That is, the output of the shift register 84 is fed back to the adder circuit 82, and is incremented by 1 each time it circulates.

The output of the shift register 84 is sent to the comparator circuit 8.
It is supplied to the A terminals of 5 and 87. The B terminals of the comparison circuits 85 and 87 each have a threshold value circuit 8 set to a predetermined value.
6 and 88 are connected. Threshold circuit 88 generates a threshold Te that defines the period, and threshold circuit 86 generates a threshold T- which is slightly lower than Te.

Comparing circuits 85 and 87 generate output pulses φ- and φe, respectively, when the signals input to the A and B terminals become equal. That is, when the output signal of the shift register 84 gradually increases, the signal φ- is first generated, and then the signal φe is generated.

This signal φe is inverted by an inverter 90 via an OR circuit 89 and supplied to an AND gate 83. That is, when the signal φe is generated, the output of the AND gate 83 becomes 0. Therefore, shift register 8
The output of No. 4 increases monotonically as shown in FIG. 9(B), returns to 0 when it reaches the maximum value, and increases monotonically again, forming a repetitive sawtooth wave. The peak value of the sawtooth wave is equal to Te.

The signal φ- is generated just before the output of the shift register 84 reaches the peak value, and then the signal φ- is generated from the peak value to 0.
When returning to , signal φe is generated. These signal waveforms are shown in FIGS. 9(C) and (D), respectively.

Note that when a key-on pulse is generated, 0 is supplied to the AND gate 83, and even if the counter output is in the process of counting up, the shift register 84 is reset and a new count is started.

FIG. 10 shows an example of the configuration of the utilization device 15 shown in FIG. In this configuration, the tone forming portion of the electronic musical instrument when the light amount changing device 4 is configured with a touch detection keyboard constitutes the utilization device 15.

Touch data representing the key pressing speed output from the subtraction circuit 14 is supplied to a selector 91, and depending on the mode selected by the selector 91, the touch data is sent to one or two of the OR circuits OR1 to OR5. More than that is supplied. The outputs of these OR circuits 93 are respectively supplied to a tone parameter input terminal, a vibrato speed input terminal, a vibrato depth input terminal, a pitch terminal of a musical tone signal generation circuit 94, a volume input terminal of a multiplication circuit 95, and the like.

The musical tone signal generating circuit 94 is also supplied with a keying signal KING and a key-off signal KOF, and generates musical tone signals based on key depression operations. Musical tone signal generation circuit 94
The output signal of is given an envelope by a multiplication circuit 95.

After that, the musical tone signal is passed through the accumulator (
The signal passes through an ACC) circuit 96 and a register (REG) circuit 97, is converted into an analog signal by a digital-to-analog converter 98, and is generated as a musical tone from a speaker 100 via an amplifier 99.

Note that the mode of the selector 91 is sequentially changed by a signal supplied by the selector counter 92. For example, when a switch is pressed, the selector increases sequentially from 0 and returns from 7 to 0 again. Releasing the switch at the desired position selects that mode.

Note that smoothing means C0 (not shown) may be inserted into the input of the selector 91. This means C0 is a smoothing circuit that shapes the falling waveform of the touch data S2 into arbitrary waveforms such as S21 to S23 as shown by various dashed lines in FIG. 12(A), which will be described later.

For example, to hold the peak as in S21, a peak hold circuit that latches the peak data at the time of peak detection may be used, and to attenuate as in S22 and S23, a peak hold circuit may be used that has an attenuation rate and an attenuation target value. A decay circuit is fine.

Incidentally, when the selection means 26 is set to the a side, the touch data S2 rises as a solid line and the output signal of the comparator circuit 23 becomes "0" at the point when it reaches the peak, so it is indicated as a double dotted line. It is reset to "0" as shown.

Thereafter, if the key is not moved until the key is released, the touch data S2 remains at the "0" level,
When the key is released, input B of the comparator circuit 23 is initially larger than A, so it maintains the "0" level, but as shown by the double dotted line and the double dot chain line, it becomes almost negative. Outputs from peak level to "0" level at any time. After that, the touch data S2 maintains the "0" level unless the key is pressed continuously, but if the key is pressed continuously, the touch data S2 remains at the "0" level.
It increases until it reaches a peak as shown by the dotted chain line.

[0080] Here, considering the case where the selection means 26 is set to the b side, all the touch data S2 during the key depression
is output, so it rises as shown by the solid line, and when the key comes into contact with the lower limit stopper, the key stalls, so it falls as shown by the solid line. The negative dotted line is some key bound output. When the key is released after a predetermined period of time has elapsed, the signal will rise from the “0” level to a negative peak as shown by the dotted line to the two-dot chain line, and then “
It returns to the 0'' level. If the key is pressed again, it rises and falls again as shown by the two-dot chain line.

That is, in this circuit system (FIG. 1), touch data is updated any number of times during a key depression. Therefore, even if the key is pressed and released a little too slowly, or in other words, if the key is played weakly and quickly, the touch data will be output accordingly. By using or not using the smoothing means, it is possible to obtain a multi-step or one key press speed and/or key release speed depending on the purpose of the device used.

Furthermore, the correction means C is connected to the input of the selector 91.
1. Correction means C2~ are also connected to the input of the musical tone signal generation circuit 94.
C5, a correction means C6 is provided at the input terminal of the multiplication circuit 95;
It is also possible to correct each input signal.

FIG. 11 shows an example of the structure of such a correction means. Regarding the touch data S2 in FIG. 11, in order to better obtain the pianissimo effect described later, the selection means 26 is
It is desirable that S2 be selected on the side. The a side may be selected simply as a substitute for the delay circuit of the smoothing means C0 described above. The following description will be made on the condition that side b is selected.

FIG. 12 shows a virtual signal waveform for one channel of the multiplexed signal. Touch data S2 representing the key press speed supplied from the subtraction circuit 14 and the like in FIG. 1 is supplied to the extreme value detection circuit 102 and the zero or less cut circuit 108.

[0085] In the key pressing operation, the key pressing speed is shown in Fig. 12 (A
), it first rises, then decreases, and reaches zero at the lowest point. At this time, the touch data S2 slightly overshoots near the lowest point and then stops after returning, so the touch data S2 also changes somewhat to the negative side as shown by the broken line.

The below-zero cut circuit 108 has an input signal of 0.
When the value below is reached, that component is removed and the input signal is transmitted to the output side only while the signal is positive. This signal is designated as S3, and Figure 1
2(A). Further, while the input signal is positive, a signal a1 which becomes 1 is generated. This signal s1 is shown in FIG. 12(B).

Note that the touch data signal S3 from which 0 or less has been cut is applied to the adder circuit 109. Addition circuit 1
In addition to being output as is, the output signal of 09 is output from delay circuit 1.
The signal is supplied to the multiplication circuit 118 via 17, multiplied by a predetermined coefficient, and the product is applied to the addition circuit 109. That is, in the addition circuit 109, the zero or less cut touch data S3 and the increment obtained by performing predetermined processing on the output signal are added to form corrected touch data S4.

The extreme value detection circuit 102 operates as shown in FIG.
An output signal a2 as shown in 2(C) is generated. The AND circuit 110 receives the signals a1 and a2, and outputs an output signal a3 as shown in FIG. and sets the addition/subtraction counter 113 to addition mode. Touch data S2 becomes 0, and signal a
When 1 becomes 0, the output of the AND circuit 110 changes to 0, and the addition/subtraction counter 113 enters the subtraction mode. That is, the addition/subtraction counter 113 starts subtraction when the touch data S2 becomes 0.

Signal a2 is applied to OR circuit 104 directly or via time division flip-flop circuit 103. The time division flip-flop circuit 103 also receives a key-off signal KOF. The OR circuit 104 combines the output a2 of the extreme value detection circuit 102 and the time division flip-flop circuit 10.
In response to the output a6 of 3, the output a4 as shown in FIG. 12E is generated after the touch data S2 reaches the maximum value until the key is turned off, and the AND circuits 112 and 114 are turned on. The AND circuit 112 is a digital volume 1
The value set in step 11 is supplied to the addition/subtraction counter 113. The AND circuit 114 supplies the output signal of the addition/subtraction counter 113 to the shift register 115 while it is on. The output signal a5 of the shift register 115 is sent to the addition/subtraction counter 113.
is fed back to the digital volume 111, and addition and subtraction are performed by the unit amount set by the digital volume 111. Addition/subtraction counter 113
When is first set to addition mode and then set to subtraction mode, the output of shift register 115 is a5 as shown in FIG.
As shown in F), it first increases and then decreases.

The signal a5 changing in this way is transmitted to the multiplier circuit 1.
18. The multiplication circuit 118 is the addition circuit 109
The touch data S4 generated by the delay circuit 117 delays the touch data S4 by a certain period of time, and forms the product of the signal generated by the shift register 115, which increases at the beginning and then decreases. supply

The operation of the circuit shown in FIG. 11 will be summarized with reference to the waveform diagram shown in FIG. 12. FIG. 12A shows a signal S3 obtained by removing the negative component of the input touch data S2. While this signal S3 exists, a signal a1 is generated as shown in FIG. 12(B). Note that the negative component of the touch data S2 is shown by a broken line in FIG. 12(A).

The extreme value detection circuit 102 detects the touch data S2.
12 (
A signal a2 as shown in C) is generated. AND circuit 11
0 takes the product (common part) of signals a1 and a2, and
A signal a3 as shown in FIG. 2(D) is generated and supplied to the addition/subtraction counter 113. The OR circuit 104 generates a signal a4 that becomes "1" after the touch data S2 reaches its maximum value until the key is turned off. While the signal a4 is present, the AND circuits 112 and 114 are turned on, activating the circuits. The addition/subtraction counter 113 performs addition while the output signal from the AND circuit 110 is present, and performs subtraction when the output signal disappears, forming a signal a5 that gradually increases and then decreases as shown in FIG. 12(F). do.

In this way, the addition/subtraction counter 113 gradually increases its value by the unit amount set by the digital volume 111 while the signal a3 is present, and the signal a3
After the value is exhausted, the value is gradually decreased and the value is output from the shift register 115. The touch data delayed by the delay circuit 117 is multiplied by such a coefficient in the multiplier circuit 118, and added to the touch data S3 from which 0 or less is cut, producing a signal as shown in FIG. 12(G) as an output S4. create. When the key press speed is maximum, the envelope is maximum.

Note that when the touch data S3 has a sharp shape, the circuit shown in FIG. 11 works to slow down the fall of the signal as shown in FIG. 12(G).

Depending on the shape of the touch data S2, the peak position of the output of the adding circuit 109 may shift backward in time as shown in FIG. 12(H). For example, in the case of pianissimo (pp), such a possibility exists.

Here, in order to make the envelope as touch data attenuate more gently than in FIGS. 12(G) and (H), as shown in FIG. 19,
If two types of manually settable digital volume I 111a and digital volume II 111b are provided and the value of digital volume II 111b is set to a small value, (I) corresponding to FIG. 12(G) and (H) corresponding to ( A waveform with a gentle attenuation envelope as shown in J) is obtained.

[0097] Furthermore, the digital volume I111a is
Since it is used to set the increase coefficient value of the addition/subtraction counter 113, a critical value at which the peak position deviates backward from the key press timing can be determined by adjusting the set value.

In other words, if we define the pianissimo effect as an effect in which the peak position shifts behind the key press timing or the peak position continues for a predetermined time due to a weak touch,
The digital volume I111a is a volume that can set a critical value at which this pianissimo effect appears. The above-mentioned pianissimo effect is an effect achieved for the first time in the field of electronic musical instruments.

Expressing this effect in another way, when you play a natural stringed instrument with relatively low tension, such as the viola da gamba, the strings and body other than those being played are slightly distorted. It has something in common with the phenomenon of resonance occurring at a time lag, where the resonance reaches its peak and the musical sound expands. However, I would like to add that in the case of the viola da gamba, this phenomenon often appears during normal performance, even if it is not pianissimo.

Some of the components of the circuit shown in FIG. 11 will now be described in more detail.

FIG. 13 shows an example of the configuration of the extreme value detection circuit 102. In the extreme value detection circuit 102, touch data S
2 is applied to delay circuit 121 and comparison circuit 122. The delay circuit 121 delays the touch data S2 to generate a signal S2.
d is formed and inputted to the B terminal of the comparison circuit 122. The comparison circuit 122 receives the touch data S2 applied to the A terminal, and
The corresponding delayed touch data S2d applied to the B terminal is compared, and while the signal at the B terminal is greater than the signal at the A terminal, an output signal a2 is generated. It is assumed that the touch data S2 applied to the A terminal has a shape as shown by the solid line on the right side of the figure. Then, the signal S which is delayed from this signal is
2d has a shape as shown by a broken line. Therefore, the period in which the delayed data S2d is larger than the touch data S2 is the period from the maximum value to the minimum value, which is indicated by the arrow in the figure. During this period, comparator circuit 122 provides output a2.

FIG. 14 shows an example of the configuration of a zero or less cut circuit. In the 0 or less cut circuit 108, the selector 12
4 receives touch data S2 at its "0" terminal, and receives "0" from the "0" generation circuit 125 at its "1" terminal. The output of the selector 124 is touch data S3 with 0 or less cut off.
On the other hand, it is input to the A terminal of the comparator circuit 126. The B terminal of the comparison circuit 126 is connected to the “0” generation circuit 1.
Input "0" from 27.

The first output terminal of comparator circuit 126 produces an output a1 while signal A is greater than signal B. That is, while the touch data S2 is positive, the signal a1 is generated. On the other hand, the second output terminal generates an output signal when the signal A is equal to or smaller than the signal B, and the selector 12
4 "1" selection terminal. That is, when the touch data S2 becomes 0 or negative, the selector 124 becomes "0".
"0" from the generation circuit 125 is selected and the output signal S3
Supply as. In this way, the output signal S3 becomes the touch data S2 with the negative component removed.

FIG. 15 shows an example of the configuration of a time division flip-flop circuit. In the time division flip-flop circuit 103, the output signal a2 of the extreme value detection circuit 102 is applied to the set terminal S, and the key-off signal KOF is applied to the reset terminal R.
is applied. The signal a2 applied to the set terminal S is
The signal is supplied to the shift register 132 via the OR circuit 131. The output of the shift register 132 is sent to the AND circuit 1
Returned on 33rd.

The AND circuit 133 is connected to the shift register 13
2 and a signal obtained by inverting the key-off signal KOF by an inverter 134 to generate AND logic. That is, while the output of the shift register 132 is present and the key is not turned off, the AND circuit 133 outputs the OR circuit 1.
31 is given an output signal "1". In this way, the OR circuit 131 outputs a signal a6 that keeps the corresponding bit at "1" until the key is turned off after the touch data S2 reaches the maximum value.
occurs.

The OR circuit 104 in FIG. 11 calculates the sum of the output of the time division flip-flop circuit 103 and the output a2 of the extreme value detection circuit 102, and after the touch data S2 reaches the maximum value, the key is turned off. Until then, an output signal a4 of "1" is generated. In this way, the circuit function of FIG. 11 is realized.

[0107] Creating a difference in touch sensitivity between white keys and black keys on a keyboard, creating a difference in touch sensitivity depending on the key range on the keyboard, creating a difference in touch sensitivity depending on the type of keyboard, etc. is as shown in Figure 1. In the embodiment, this can be implemented by providing a difference in signal transmission rate among a large number of optical switches formed on the optical switch board 42, but it can also be implemented by the following configuration.

FIG. 16 shows an example of the configuration of a touch sensitivity adjustment device. In this configuration, the optical distributor 2 in FIG. 1 has the same configuration as the optical multiplexer 8, and the optical distributor 2 has a multiplex function. Instead of optical multiplexer 8,
Insert the configuration shown in Figure 16. FIG. 16(A) is a schematic cross-sectional view showing the configuration.

[0109] Fiber coupling board 41 and optical switch board 4
2, and an analyzer plate 137 is provided between the optical switch board 42 and the lens member 43.

The polarizing plate 136 has a uniform polarization axis direction over the entire surface, as shown in FIG. 16(B).

The analyzer plate 137 has a structure as shown in FIGS. 16(C) to 16(F). Further, the optical switch board 42 is
It is assumed that an optical switch is two-dimensionally incorporated, which is driven in synchronization with an optical multiplexer and rotates the polarization axis of incident light by a predetermined angle. Then, when the optical switch of the optical switch board 42 is turned on, the incident light that passes through the polarizing plate 136 and has a polarization axis in a certain direction rotates the polarization axis by a predetermined angle and is emitted.

The case where the analyzer plate 137 has the configuration shown in FIG. 16(C) will be described below. The analyzer plate 137 has three regions 138, 139, and 140. In the region 138, the polarization axis is set to be perpendicular to the polarization axis of the polarizing plate 136 when the optical switch is off, and parallel to the polarization axis when the optical switch is on. In the region 139, the polarization axis is deviated by a predetermined angle from the orthogonal relationship with the polarization axis of the polarizing plate 136 when the optical switch is off, and is deviated from the parallel relationship by a slight predetermined angle when the optical switch is on. That is, the polarization axis of the region 139 when on is the same as that of the region 139.
It is set to be slightly shifted from the polarization axis of the incident light incident on 9. In region 140, the polarization axis is further tilted when turned on.

In the optical fiber arranged in the area 138, the light is polarized in a predetermined direction by the polarizing plate 136, and the polarization axis is rotated by a predetermined angle by the optical switch of the optical switch board 42. As a result, in the area 138 of the analyzer plate, the light is polarized in a predetermined direction.
The light is analyzed by an analyzer plate parallel to the incident light in the area 138,
The transmitted light according to the optical rotation angle forms output light. That is, in the region 138, the light input from the front of the polarizing plate is
Forms output light with almost no attenuation. Areas 139, 140
In this case, the polarization axis of the analyzer plate is tilted so that it is slightly shifted from the direction of the polarization axis of the emitted light.
The output light becomes smaller in the order of 39 and 140. Therefore, regions 138, 139, 140 provide progressively decreasing output light for the same incident light.

For example, by assigning area 140 to keys in the center, area 139 to keys slightly far from the player, and area 138 to the keys farthest from the player, touch sensitivity due to differences in key areas can be reduced. Can be corrected. In addition, areas 138 are arranged in order from the bass side for each predetermined octave.
, 139, and 140 to correct the touch sensitivity in three stages. In addition, although the example of three stages was shown above,
The correction may be made in multiple stages, and may be corrected in half-octave units.

Similarly, when a plurality of keyboards are provided, differences in sensitivity between the keyboards can be corrected.

Setting of different sensitivity areas on the analyzer plate is as follows:
It is not limited to what is shown in FIG. 16(C).

FIG. 16(D) shows another method of dividing the analyzer plate into three regions. The analyzer plate 137 in FIG. 16(B) is divided into concentric rings. In each ring, the difference in sensitivity can be set by tilting the polarization axis at a predetermined angle as shown by the arrow in the figure. That is, the region 138a having the polarization axis perpendicular to the polarization axis of the polarizing plate 136 is the region with the highest sensitivity, and the region 139b inside the polarization axis tilted at a predetermined angle is the region of medium sensitivity. The central region 140b is the region with the most tilted polarization axis, and is the region with the lowest sensitivity.

Although an example has been described in which the area of the analyzer plate is divided into three parts, in the case of a keyboard, the difference in sensitivity between white keys and black keys due to the difference in key length poses a problem. The structure of the analyzer plate that compensates for this difference in sensitivity between the white key and the black key is shown in FIGS. 16(E) and 16(F). Since the distance from the fulcrum of the black keys is short, the touch appears strongly even if the player intends to play with the same touch.

That is, the keyboard is often played at the farthest point from the fulcrum. Therefore, since the distance between the abutting part of the player's finger and the white key and the fulcrum is longer than that of the black key, the same force is applied from the finger to the key to move the tip of the key in the direction in which the key is pressed. If the distance is within a unit time and the black and white keys are considered to be the same, the moving speed of the reflective surface 62 of the stroke sensor 59 at the same distance from the fulcrum will be faster for the black keys, so the player should You will begin to feel that the touch is bigger than the white key touch.

Therefore, in FIG. 16(E), in the outer peripheral area 141 of the analyzer plate to which the black key is assigned, the polarization axis is perpendicular to the polarization axis of the polarizing plate 136 when the optical switch is off, and parallel to the polarization axis when it is on. In the central region 142 to which the white key is assigned, the polarization axis is tilted at a predetermined angle in the direction of the polarization axis of the emitted light from the parallel relationship with the polarization axis of the polarizing plate 136 when turned on. By using an analyzer plate having such a configuration, it is possible to relatively increase the sensitivity of the white keys and compensate for the difference in touch sensitivity between the white keys and the black keys.

Note that the method of dividing the analyzer plate into two areas is not limited to the form shown in FIG. 16(E).

FIG. 16(F) shows another method of dividing the analyzer plate into two regions. The area of the analyzer plate 137 is divided into a black key area 141a and a white key area 142a. The black key area 141a is a polarizing plate with the same polarization axis setting as 141 in FIG.
A polarizing plate with the same polarization axis setting as 142 of 6(E) is used.

Note that the setting of the polarization axis of the analyzer plate is not limited to the above-mentioned case. Place orthogonal polarizers in areas of high sensitivity,
Various settings are possible in areas with low sensitivity, such as tilting the analyzer in the opposite direction to the direction of rotation of polarized light.

With this configuration, it is possible to compensate for differences in touch sensitivity depending on the type and position of keys in the touch detection keyboard device.

FIG. 17 shows an example of the structure of the analyzer plate as shown in FIG. 16(E). The analyzer plate 137 is constructed by overlapping a first plate shown in FIG. 17(A) and a second plate shown in FIG. 17(B). In the first plate shown in FIG. 17A, a polarizer 142 is formed in a central region 142 of a transparent substrate 144, and an outer region 143 is a transparent region. On the other hand, in the second plate, a polarizer is formed in the outer ring-shaped region 141 of the transparent substrate 145, and the central region 143 is made a transparent region. 1st board,
In the second board, the boundaries of the regions are set to be the same. The polarization axis of the central region 142 of the first plate is tilted at a predetermined angle from a predetermined direction as shown in the figure, and the polarization axis is overlapped with the second plate as shown in FIG. 16(E).
An analyzer plate 137 as shown in FIG.

[0126] It will be obvious to those skilled in the art that analyzing plates of other configurations can also be produced by the same method.

[0127] Note that correction of touch data can also be performed in various forms other than the one shown in Fig. 11.

In the configuration shown in FIG. 18A, {(A+
Touch data is corrected using an arithmetic circuit that performs the calculation of B)/2}×(B/A).

FIGS. 18B and 18C illustrate different forms of speed change. In FIG. 18B, when the time Δt elapses while the displacement of the key changes from P1 to P2, and the key pressing speed v1 at the displacement P1 and the key pressing speed v2 at the displacement P2 are equal (v1= v2=v).

On the other hand, in FIG. 18(C), the time difference Δt elapsed from the displacement P1 to the displacement P2 is the same as in the case of FIG. 18(B), but the key pressing speed v1 is the same as that in the case of FIG. This is 1.5 times the speed v, and the key pressing speed v2 at the displacement P2 is half the key pressing speed v in FIG. 18(B). In such a case, if the average value is adopted as the key pressing speed, in the case of FIG. 18(B), v1=v2=v, and in the case of FIG. 18(C), v1=1.5v, v2=0. 5
v, and (v1+v2)/2=v, so the average speeds are the same. By using the touch data correction circuit shown in FIG. 18(A), it is possible to provide a difference in the detection speed of such key press forms. That is, in the case of FIG. 18(B), the detected speed V=v, while in the case of FIG. 18(C), V=3v.
becomes. By using such touch data, musical tones can be changed according to the performer's will, and the expressiveness of the performance can be increased.

[0131] The technique described above can also be applied to player pianos. That is, a stroke sensor is provided under each key of the piano, and touch data and key data when playing the piano are input into an automatic performance memory. During playback, the pitch is controlled using key data, and the movement of the key that is pulled in using a magnet is controlled using touch data that differs in time in multiple steps for each key, thereby faithfully reproducing keyboard movements and performances. It becomes possible to do so. Furthermore, by being able to faithfully reproduce touch sensations or keyboard movements, it becomes possible to learn the habits of famous performers by tracing and practicing.

[0132] The present invention has been explained above according to the examples, but
The present invention is not limited to these. for example,
It will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

[0133]

Effects of the Invention Since a single light source or light receiving element can be used for a plurality of light amount changing devices, variations in characteristics can be reduced.

[0134] Furthermore, since the number of parts can be reduced, manufacturing costs can be reduced.

[0135] In the touch detection keyboard of an electronic musical instrument, the sensitivity of the touch detection device to a large number of keys can be made uniform.

[0136] By using such a keyboard, an electronic musical instrument with rich expressive power can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the entire system.

FIG. 2 shows an example of the configuration of an optical multiplexer used in the embodiment of FIG. 1. FIG. 2(A) is a cross-sectional view showing the cross-sectional structure, and FIG. 2(B) is an exploded view.

3 shows a configuration of an optical coupling section of the optical multiplexer shown in FIGS. 1 and 2. FIG. Figure 3 (A) is a cross-sectional view of the optical coupling part of the input signal fiber, Figure 3 (B) is a cross-sectional diagram of the optical coupling part of the central optical waveguide, and Figures 3 (C) and (D) are cross-sectional views of the optical coupling part of the input signal fiber. FIG. 3 is a cross-sectional view showing a process of creating a joint.

4 shows the structure of an optical switch board of the optical multiplexer shown in FIG. 2. FIG. FIG. 4(A) is a partial perspective view, and FIG. 4(B) is a partially enlarged cross-sectional view.

5 is a perspective view showing a touch detection keyboard as an example of the light amount changing device shown in FIG. 1. FIG.

6 shows a stroke sensor used for touch detection of the touch detection keyboard shown in FIG. 5. FIG. FIG. 6(A) is a sectional view of the stroke sensor, and FIG. 6(B) is a partial perspective view thereof.

7 is a block diagram showing a configuration example of a time division delay circuit used in the circuit of FIG. 1. FIG.

8 shows an example of the configuration of a time division differential circuit used in the embodiment shown in FIG. 1. FIG. FIG. 8(A) is a circuit block diagram, and FIG. 8(B) is a waveform diagram showing signal waveforms at key points.

9 shows a configuration example of a time division timer counter used in the embodiment shown in FIG. 1. FIG. 9(A) is a circuit block diagram, and FIG. 9(B), (C), and (D) are the circuit block diagrams of FIG. 9(A).
FIG. 3 is a signal waveform diagram at key points of the circuit.

10 is a circuit diagram showing an example of a device used in the embodiment of FIG. 1. FIG.

11 is a block diagram illustrating an example of a touch data correction circuit that can be used in combination with the embodiment shown in FIG. 1. FIG.

12 is a waveform diagram showing signal waveforms in essential parts of the circuit in FIG. 11. FIG.

13 is a block diagram and a signal waveform diagram showing a configuration example of an extreme value detection circuit in the circuit of FIG. 11. FIG.

14 is a block diagram and a signal waveform diagram showing a configuration example of a zero or less cut circuit in the circuit of FIG. 11. FIG.

15 is a block diagram showing a configuration example of a time division flip-flop circuit in the circuit of FIG. 11. FIG.

FIG. 16 shows the configuration of a touch sensitivity adjustment device used in another embodiment of the present invention. FIG. 16(A) is a cross-sectional view showing the configuration of the touch sensitivity adjustment device, FIG. 16(B) is a plan view showing the configuration of the polarizing plate, and FIGS. 16(C) to (F) are plan views showing the configuration of the analyzer plate. It is a diagram.

FIG. 17 shows a method for creating the analyzer plate shown in FIG. 16(E). FIG. 17(A) shows the configuration of the first plate, and FIG.
(B) shows the structure of the second plate.

FIG. 18 shows a touch data correction circuit according to another embodiment of the present invention. FIG. 18(A) is a block diagram of the circuit, and FIGS. 18(B) and (C) are graphs showing examples of speed changes.

FIG. 19 is a block diagram showing a modification of the correction circuit.

[Explanation of symbols]

Claims (2)

[Claims] 1. A plurality of first optical waveguide means, a plurality of optical waveguides optically coupled to the plurality of first optical waveguide means, arranged two-dimensionally on a single substrate, and for changing the polarization state of incident light. a pair of polarizing means disposed sandwiching the polarization changing means, at least one of which is divided into a plurality of regions, each region having a different polarization axis direction; Regarding the pair of polarizing means, a single second optical waveguide means disposed on the opposite side to the first optical waveguide means, and a plurality of first optical waveguide means and the single second optical waveguide means A multi-light path optical system comprising a pair of polarizing means and an optical system optically coupled via the plurality of polarization changing means. 2. The multi-optical optical system according to claim 1;
optically coupled to each of the plurality of first optical waveguide means,
A plurality of light amount changing means including an optical input port, an optical output port, and a changing means for changing the amount of light directed from the optical input port to the optical output port, and a plurality of keys corresponding to the plurality of light amount changing means. What is claimed is: 1. A touch response device for an electronic musical instrument, comprising: a keyboard means having a keyboard; and an actuator section that drives a corresponding change means of a light amount change means in response to a key depression operation.