JP2608738B2 - Electronic keyboard instrument - Google Patents

Description

The present invention relates to an electronic keyboard instrument also called, for example, a synthesizer.

(Prior art) In an electronic keyboard instrument, for example, as disclosed in Japanese Patent Publication No. 58-57119, Japanese Patent Application Laid-Open No. 56-161594, etc., one key is provided with at least two switches,
The time when these two switches are turned on and off at the time of key press and key release is measured to detect the key press and key release speeds. Is controlled to control the fall speed of the sound in accordance with the key release speed, and is used for giving inflection to the performance.

"Problems to be Solved by the Invention" As the first switch and the second switch attached to the key, those using contacts or those using conductive rubber are used. When the key is pressed, for example, the first switch is used. , The second switch is turned on in that order, and at the time of key release, the second switch is turned off first, and then the first switch is turned off. The key return speed and the key release speed are detected by measuring the return time difference.

However, although the first switch and the second switch operate in a predetermined order in the early stage of manufacturing, the operating order of the first switch and the second switch may be reversed due to a change with time of the contact portion during use.

When the operation order of the first switch and the second switch is reversed, there is a disadvantage that conventionally, the key depression speed and the key release speed cannot be detected.

For this reason, for example, it is conceivable to use a so-called one-circuit two-contact switch of a type in which one contact alternately contacts two contacts. By using the switch having this structure, the phenomenon that the order of the contact signals is reversed can be avoided.

However, this one-circuit, two-contact type switch has a disadvantage in that rubber is expensive due to the complicated contact structure. There is also the disadvantage that this type of switch cannot be made using conductive rubber.

Accordingly, in many cases, the cost is limited, and two switches of one circuit and one contact type are used, so that the above-described problem occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic keyboard musical instrument having a function of correctly measuring a key pressing speed and a key releasing speed even when the operation order of the first switch and the second switch is reversed.

In the present invention, a first switch and a second switch, which are provided in association with a key of a musical instrument and which are turned on and off with a time lag when a key is pressed and released, Determination signal generating means for performing a logical operation on signals output according to the on / off states of the first switch and the second switch to output a determination signal indicating a key pressing process and a key releasing process; Time signal generating means for outputting a time signal corresponding to the time difference between the on and off operations of the two switches; time measuring means for measuring the length of the time signal output from the time signal generating means; End signal generating means for outputting a signal indicating the end of the key process and a signal for notifying the end to the outside; and a discrimination signal output from the discrimination signal generating means in response to the end signal output by the end signal generating means And an output circuit that fetches a signal corresponding to the time measured by the time measurement unit and outputs it to the outside, and a notification signal that notifies the outside that a new discrimination signal and time measurement signal have been fetched into this output circuit Means and an electronic keyboard instrument.

According to the electronic keyboard instrument of the present invention, the initial condition of the contact signals transmitted from the two switches is the same regardless of which of the first switch and the second switch is turned off or on first. It is possible to determine by a logical operation whether the process is a key pressing process or a key releasing process based on the difference between “1” and both “0”, and outputs a discrimination signal representing the key pressing process and the key releasing process. .

The time signal generating means outputs a time signal having a pulse width corresponding to a time difference between when the first switch and the second switch are turned on and off, and the length of the time signal is measured by the time measuring means.

The end signal generating means outputs a signal indicating the end of the key pressing process and the key releasing process.

Therefore, when a signal indicating the end of the key press process or the end of the key release process is output from the end signal generation means, the measurement result of the time measurement means, the time measurement value output from the determination signal generation means, and the determination signal are output to the output circuit. It is taken in and updates the value held in the output circuit.

At the same time, a signal output from the end signal generating means is sent to the outside to notify the outside that the held value of the output circuit has been updated.

As described above, according to the present invention, the key pressing process and the key releasing process are determined by performing a logical operation in consideration of the initial condition of the logic signal transmitted from the first switch and the second switch.
Whichever of the first switch and the second switch operates first, the key pressing process and the key releasing process can be determined.

Therefore, even if the on and off timings of the first switch and the second switch are reversed due to a change over time during use, the key pressing speed and the key releasing speed can be accurately measured.

Therefore, according to the present invention, although the inexpensive switches are used as the first switch and the second switch, the first switch is used.
Even if the on and off timings of the switch and the second switch are reversed, the key press speed and the key release speed can be accurately measured, and a highly reliable electronic keyboard instrument can be provided.

FIG. 1 shows an embodiment of the present invention. Here, for the sake of simplicity, a plurality of key contacts originally provided for a plurality of keys of the electronic keyboard instrument are omitted, and a set of a first switch B and a second switch M for one key are omitted. (Hereinafter, these are referred to as contacts B and contacts M).

One key has two independent contacts B and M. When a key (not shown) is pressed, a normal contact state transition is performed, and first, the contact B is turned on (key pressed). (Start) Then, the contact M is turned on (key depression is completed).

At this time, the time from when the contact B is turned on to when the contact M is turned on is referred to as a "key pressing speed", and this process is referred to as a "key pressing process". A value corresponding to the time required for the key pressing process is referred to as an initial touch count.

Next, when the released key is released, first, the contact M is turned off (key release is started), and then the contact B is turned off (key release is completed). At this time, the time from when the contact M is turned off to when the contact B is turned off is called "key release speed", and this process is called "key release process". A value corresponding to the time required for the key release process is called a release touch count.

 Next, the circuit connection of FIG. 1 will be described.

In FIG. 1, 100 is a drive signal generation circuit, 200 is a discrimination signal generation means for discriminating a key pressing process and a key release process, 300 is a time signal generation device, 400 is a time measurement device, 500 is an end signal generation device, and 600 is a termination signal generation device. Each output circuit is shown.

The drive signal generation circuit 100 includes a master clock generator 13,
A master clock output from the mast clock generator 13 is converted into polyphase pulses 1P8, 2P8, 3P8,... 6P8 shown in FIG.

The polyphase pulses 1P8 to 6P8 are the master clocks shown in FIG. 2A.
Processing slots 1, 2, 3 ... 8, 1, 2 in units of 4 cycles of CP
, And is repeatedly output with eight processing slots as one cycle. One of the polyphase pulses 1P8 refers to a pulse output for each first processing slot 1. The time for the processing slot is called one key slot.

Each of the contact points B and M has one terminal connected to the ground potential, and the other terminal is pulled up by the resistor R and connected to the data input terminal D of the D flip-flops 2 and 3. The D flip-flops 2 and 3 sample the ON and OFF states of the contacts B and M at fixed time intervals. When the contacts B and M are in the ON state, in this example, a logic 0 is set, When M is in the OFF state, a logic 1 is sampled, and the sampled value is output to the Q terminal every time a multiphase sample 1P8 is input.

The discrimination signal generating means 200 includes two D flip-flops 1
And 4 and a logical operation circuit 7. The D flip-flop outputs a direction flag (hereinafter referred to as DF) as a determination signal indicating whether the key is in the process of being pressed or released.

This DF is a flag necessary for performing accurate condition determination because there is no distinction between a key pressing process and a key releasing process only with the ON / OFF information of the contact points B and M. here
When DF = 0 logic, the key pressing process is defined, and when DF = 1 logic, the key releasing process is defined.

By supplying the multi-phase pulse 1P8, the D flip-flops 1,
DF latched in 2 and 3, ON / OFF information of contact B (hereinafter referred to as B), ON / OFF information of contact M (hereinafter referred to as M)
Is input to the logical operation circuit 7. The logical operation circuit 7 is DF,
The following logical operation is performed according to the logic of B and M, and output.

TCEN = BM ... (2) ▲ ▼ is called an event occurrence flag and the contact B is turned on (B =
0) and the contact M is on (M = 0), and only when the contact B is off (B = 1) and the contact M is off (M = 1) in the key release process (DF = 1). ▲ ▼ = 0, and in other states, ▲ ▼ = 1.

In other words, when ▲ ▼ = 0, it means that the key has changed from the key-pressing process to the key-pressing completed state, or that the key has changed from the key-release process to the key-release completed state. ▲
▼ is latched in the D flip-flop 5 by the multiphase pulse 2P8.

The time signal generating means 300 can be constituted by a D flip-flop, and outputs a time signal to the output terminal Q by latching the touch count enable signal TCEN output from the logical operation circuit 7 with the multiphase pulse 2P8. From equation (2), the contact M is off (M = 1) when the contact B is on (B = 0) or the contact M is on when the contact B is off (B = 1), regardless of the value of DF according to equation (2). When (M = 0), TCEN = 1, contact B is on (B = 0) and contact M is on (M = 0), or contact B is off (B =
1) When the contact M is off (M = 1), TCEN = 0. That is, when TCEN = 0, it indicates that the key press or key release is completed, and when TCEN = 1, it indicates that the key is in the key press process or in the key release process.

The signal DFOUT output from the logical operation circuit 7 is called a direction flag (DF) update value.
And ▲ ▼ = 0, or DF = 1 and ▲
When ▼ = 1, DFOUT = 1, DF = 1 and ▲
When ▼ = 0, or DF = 0 and ▲ ▼
DFOUT = 0 when = 1.

This is when the key is depressed or released (▲ ▼
(When = 0), outputs a value obtained by inverting the logic of the DF, and outputs the same logical value as the input DF when the key is pressed or released. This DFOUT is latched by the flip-flop 4 with the multi-phase pulse 5P8.

The time measuring means 400 is a D flip-flop 8 in this example.
, A full adder circuit 9 and a D flip-flop 10.

This time measuring means 400 is connected to the terminal ▲ ▼ of the register 10.
In the state where the time signal of logic 1 is given from the time signal generating means 300, the operation of counting the number of times the multiphase pulse 1P8 is given to the register 8 is performed. Therefore, as another structure, the time measuring means 400 can be constituted by an AND gate and a counter.

The output of this example register 10 is always 1 logic applied to the LSB terminal B ₀ at one input terminal B ₀ .about.B ₇ of full adder circuit 9 through the NAND gate 9A is in a state of not reaching the all-1 logic. The 1 logic is input to the input terminal D ₀ of by the register 10 output to the output terminal S ₀ of the adder 9B. When the polyphase pulse 6P8 is applied to the register 10,
Latch operation for outputting the 1 logic SB output terminals Q ₀ is performed. Register by multiphase pulse 1P8 is supplied to the register 8 8 performs the latch operation for outputting a first logic to the output terminal Q _0. When the register 8 outputs a 1 logic output terminal Q _0, the first logic is applied to the input terminal A ₀ of the adder 9B. The adder 9B adds the 1 logic applied to the input terminal B ₀ through 1 logic and NAND gate 9A is applied to the input terminal A _0, it outputs 1 logic output terminal S _1, and outputs the 0 logic S ₀ . Thus, each time the multiphase pulse 1P8 is supplied to the register 8, the added value of the adder 9A increases by "1". This situation is shown in the following table.

Input A ₇ to A ₀ When becomes all "1" B ₀ is "0" next to the adders 9A, then adding operation is stopped.

Therefore, for example, by looking at the value output from the register 8, a measurement value corresponding to the length of the time signal output by the time signal generator 300 can be obtained. Therefore, the output of the register 8 is given to the output circuit 600, and is taken into the output circuit 600 at the end of the key press and key release process. That is, the output circuit 600
Is a D flip-flop. The clock input terminal CK is supplied with an end signal output from the end signal generating means 500 at the end of each of the key pressing process and the key release process, and the time given from the time measuring means 400 by the end signal. The measured value and the discrimination signal indicating the key press and the key release output from the discrimination signal generating means 200 are latched, and the key press or key release information and the time measurement value are given to the external processing means. At this time, the end signal output by the end signal generation means 500 is output to the output circuit 600 to notify the outside that new data has been latched, for example, as an interrupt signal ▲ ▼.

The end signal generating means 500 can be constituted by an OR circuit. Polyphase pulse 4P to one input terminal of OR circuit
8 and ▲ output from the logic operation circuit 17 to the other input terminal. In this example, a case is shown in which ▲ output from the logical operation circuit 17 is latched by the D flip-flop 6 and the latch output is supplied to the end signal generating means 500.

The initial touch count operation when a key is pressed due to a normal contact state transition is described below in a time chart No. 4.
This will be described with reference to the drawings.

First, it is assumed that the reset means (not shown) inputs a system reset operation to the ▲ terminal, and the D flip-flops 1 to 6 and the D flip-flop constituting the time signal generating means 300 are initialized. The initial setting values of each flip-flop are as follows.

Since TCEN is initially set to 0, register ▲
▼ terminal is “0” and the contents are cleared.

Now, it is assumed that the key is in the key release state and both the contact points B and M are off. In FIG. 4, the key depression is started in the key slot 1 and the contact B is turned on. This information is key slot 2
When the output of the flip-flop 2 becomes 0 in the processing slot 1 of the pulse 1P8 in the processing slot 1 and the logic operation circuit 7 satisfies the condition of the expression (2), TCEN = 1
The information of TCEN = 1 becomes pulse 2P8 and time signal generating means 3
When the value is latched to 00, the reset of the register 10 is released, and the time measurement unit 400 starts measurement.

In the section between the key slots 3 and 4, the contact B is kept on and the contact M is kept off, so that the output of the logical operation circuit 7 is continuously outputted from the state of the key slot 2. That is, since TCEN = 1 continues, the initial touch count value is accumulated in the register 10 for each key slot.

When the key depression is completed in the key slot 5 and the contact M is turned on, the output of the logical operation circuit 7 is expressed by the equations (1), (2),
(3) DEOUT changes from 0 to 1 and TCEN changes from 1 to 0 EVF
Changes from 1 to 0, and is latched by the D flip-flops 4 and 6 and the time signal generating means 300 by the pulse 2P8, respectively. Since TCEN = 0, the register 10 is reset and its contents are cleared, and the counting operation is stopped. However, the touch count data measured from the start of key press is stored in the register 8 by the pulse 1P8 before the register 10 is cleared.
Latched to.

When the key press is completed, ▲ ▼ = 0, so that the output of the end signal
The pulse shown in FIG. M is generated, and the output data of the register 8 and the output (DFOUT) of the determination signal generating means 200 are latched in the output circuit 600. Then, an external processing means (not shown) is interrupted by a pulse indicating this end, and the contents of the output circuit 600 are transferred to the outside and processed.

In the key slot 6, the key press continues, and both the contact points B and M are on. On the other hand, DFOUT is 0 in key slot 5
, The logical operation circuit 7 in the key slot 6
DF input changes from 0 to 1, and from equation (3), ▲ changes from 0 to 1, and the latch operation to the output circuit 600 is not performed.

Next, a release touch counting operation when a key is released in a normal contact state transition will be described with reference to a time chart in FIG.

In the time chart of FIG. 5, it is assumed that the key pressing has already been completed before the key slot 1 and the key pressing has been continuously performed. Therefore, DF = 1, B = 0, M = 0, DFOUT = 1, T
CEN = 0, ▲ ▼ = 1. The contents of the output circuit 600 are all 0s.

First, key release is started in the key slot 1, and the contact point M is turned off. This information is latched in the D flip-flop 2 by the pulse 1P8 in the processing slot 1 of the key slot 2. Then, only TCEN of the output of the logical operation circuit 7 changes from 0 to 1 according to the equations (1), (2) and (3). TCEN = 1
Is latched in the D flip-flop 5 by the pulse 2P8, the reset of the register 10 is released and the time measuring means
400 starts measuring the release touch count.

In the section between the key slots 3 and 4, the contact B is kept on and the contact M is kept off, so that the output of the logical operation circuit 7 is continuously outputted from the state of the key slot 2. Then, the release touch count value is accumulated in the register 10 for each key slot.

In the key slot 5, the key release is completed and the contact B is also turned off. The outputs of the logical operation circuit 7 are expressed by the equations (1), (2) and (3).
DFOUT from 1 to 0, TCEN from 1 to 0, ▲
▼ changes from 1 to 0, and pulse 2P8 changes D
It is latched by the flip-flops 4 and 6 and the time signal generating means 300.

When TCEN = 0, the register 10 is reset and its contents are cleared and the counting operation is stopped, but the tack count data measured from the start of key release is latched in the register 8 by the pulse 1P8 before the register 10 is cleared. .

Here, since ▲ ▼ = 0, processing slot 4
A pulse is generated in the output of the end signal generating means 500 at
The output data of the register 8 and the output of the D flip-flop 4 are latched in the output circuit 600. Then, the release touch count data is transferred to the external processing means and processed as in the description of the initial touch count operation.
In the key slot 6, the key release continues, and the contact B and the contact M
Both are off.

On the other hand, since DFOUT changes from 1 to 0 in the key slot 5, ▼ changes from 0 to 1 according to the equation (1), and the output circuit 60 changes.
No latch operation to 0 is performed.

As described above, when the key is pressed and released, the two contact points B and M
It can be understood that the initial touch count and the release touch count can be measured when data is turned on and off in a normal state transition, and data can be transferred to the external processing means.

Next, a description will be given of a circuit operation when the two contacts B and M are turned on and off due to an abnormal state transition when a key is pressed and released, which is a feature of the present invention.

FIG. 6 shows a time chart when the order in which the two contacts of the key switch are turned on when the key is pressed is reversed. The difference from FIG. 4 used to explain the normal contact state transition when the key is pressed is that in FIG. 4, the contact B is turned on at the key slot 1 and the key is pressed, and the contact M is turned on at the key slot 5. And the key press is completed, whereas in FIG.
, The contact M is turned on first and the key depression is started, and the contact B is turned on in the key slot 5 to complete the key depression.

On the other hand, in FIG. 6, it is assumed that the key release has already been completed before the key slot 1, and the same initial setting as in the case of FIG. 4 has been performed.

The key depression is started in the key slot 1 and the contact M is turned on. According to the equation (2), the output of the logical operation circuit 7 is the same as in FIG.
Only TCEN changes from 0 to 1 and the measurement of the initial touch count starts. In the section of the key slot 3.4, the contact B is kept off and the contact M is kept on. Therefore, the output of the logical operation circuit 7 is calculated by the equations (1), (2) and (3).
Is continuously output. Then, the initial touch count value is accumulated in the register 10 for each key slot.

When the key depression is completed in the key slot 5 and the contact B is turned on, the output of the logical operation circuit 7 becomes the equation (1), (2),
From (3), it is completely equal to the case of FIG. 4, that is, DEOUT changes from 0 to 1, TCEN changes from 1 to 0, and ▲ changes from 1 to 0.
, And the initial touch data is latched in the output circuit 600. In the key slot 6, the input of the logical operation circuit 7 becomes equal to that of FIG. 4, and the operation is the same as that of FIG.

Next, FIG. 7 shows a time chart when the order in which the two contacts B and M of the key switch are turned off at the time of key release is reversed.

The difference from FIG. 5 used in the description when the key release is performed in the normal contact state transition is that the contact M is turned off at the key slot 1 in FIG. While the contact B is turned off and the key release is completed, in FIG. 7, the contact B is turned off first in the key slot 1 to start the key release, and the contact M is turned off in the key slot 5 and the key release is performed. Is to complete.

In FIG. 7 as well, it is assumed that the key pressing has been completed before the key slot 1 as in FIG. 5, and the same initial setting as in FIG. 5 has been performed.

The key release is started in the key slot 1, the contact B is turned off first, contrary to FIG. 5, and the information is latched in the D flip-flop 2 in the key slot 2 and input to the logical operation circuit 7. From (1), (2), and (3), the output of the logical operation circuit 7 is the same as that in FIG.
T and ▲ ▼ have the same value as the key switch 1.

In the section between the key slots 3 and 4, the contact B is kept off and the contact M is kept on, so that the output of the logical operation circuit 7 keeps the state of the key slot 2 according to the equations (1), (2) and (3). Output. Then, the release touch count value is accumulated in the register 10 for each key slot.

When the key release is completed in the key slot 5 and the contact point M is turned on, contrary to FIG. 5, the output of the logical operation circuit 7 is obtained from the equations (1), (2) and (3). DFOUT goes from 1 to 0, TCEN goes from 1 to 0, ▲
▼ changes from 1 to 0, and the release touch data is latched in the output circuit 600. In the key slot 6, the input of the logical operation circuit 7 becomes equal to that of FIG. 5, and the operation is the same as that of FIG.

In the description so far, it has been described that accurate touch counting can be measured even when the order of turning on and off two contacts is reversed when a key is pressed and released due to a contact abnormality of the key switch.

The two contacts, the contact B and the contact M, are usually metal contacts or contacts using conductive rubber, but these contacts cause chattering when turned on and off due to mechanical structure. In order to prevent the initial and release touch counts from fluctuating due to the presence or absence of chattering, in the present embodiment, in the following cases, the period in which the contact is chattering is removed from the touch counts to eliminate the variation in the initial and release touch counts.

i) Elimination of chattering occurring at contact B or contact M at the start of key depression ii) Elimination of chattering occurring at contact b or contact M at the start of key release Fig. 8 shows the occurrence of chattering at contact B at the start of key depression It is a time chart.

At the time when the key slot 1 starts, it is assumed that the contact B is off and the contact M is off, and that the key release is completed, and that the D flip-flops 1 to 6 are initialized as described in FIG. .

In key slot 1, key depression is started and contact B is turned on. In key slot 2, this information is transmitted as pulse 1P8
Is latched by the D flip-flop 2 and input to the logical operation circuit 7, only the TCEN of the output of the logical operation circuit 7 changes from 0 to 1 according to the equation (2), and the touch count is accumulated in the register 10.

In FIG. 8, chattering occurs at the contact B turned on in the key slot 1, and once turned off in the key slot 2,
The state after the key slot 3 is stably turned on. The OFF information of the contact B generated in the key slot 2 is latched in the D flip-flop 2 by the pulse 1P8 in the key slot 3, and when input to the logical operation circuit, the output of the logical operation circuit 7 is only TCEN according to the equation (2). Changes from 1 to 0, the register 10 is reset, and the touch count operation stops. At this time, the D flip-flops 1 to 6
And the state of 300 is exactly the same as before the key depression is started, and when the information of ON of the contact point B is latched in the D flip-flop 2 again in the key slot 4, the touch count can be re-measured from 0. .

In this way, by removing the chattering period generated at the contact B at the start of key pressing from the touch count, it is possible to prevent the initial touch count value from being varied every time a key is pressed depending on whether chattering is present or not. Although not shown, even when an abnormal contact state transition occurs at the start of key depression and the contact M is turned on first and chattering occurs in the contact M, the eighth contact is obtained by the equations (1), (2) and (3). The chattering period can be removed from the initial touch count exactly as in the case of the drawing.

Next, a time chart when chattering occurs at the contact point M at the start of key release is shown in FIG.

In FIG. 9, it is assumed that the key depression is completed at the time when the key slot 1 starts. Therefore, the outputs of the logical operation circuit 7 are DFOUT = 1, TCEN = 0, and ▼ = 1. It is assumed that the content of the output circuit 600 is 0.

In key slot 1, key release is started and the contact M is turned off.
Is latched by the D flip-flop 2 and input to the logical operation circuit 7, and only the TCEN of the output of the logical operation circuit 7 changes from 0 to 1 according to the equation (2), and the touch count is accumulated in the register 10.

In FIG. 9, chattering occurs at the contact M turned off in the key slot 1, and once turned on in the key slot 2,
The state after the key slot 3 is stably turned off.

When the ON information of the contact M generated in the key slot 2 is latched by the D flip-flop 2 by the pulse 1P8 in the key slot 3 and input to the logical operation circuit 7, the output of the logical operation circuit 7 becomes Only TCEN changes from 1 to 0, the register 10 is reset, and the touch count operation stops.

The states of the D flip-flops 1 to 6 and 300 at this time are exactly the same as before the key release is started. Touch count can be re-measured.

In this manner, by removing the chattering period generated at the contact point M at the start of key release from the touch count, it is possible to prevent the release touch count value from being varied every time a key is released depending on the presence or absence of chattering. Although not shown, even when an abnormal contact state transition occurs at the start of key release, the contact B is turned off first, and chattering occurs at the contact B, the first contact is obtained by the equations (1), (2), and (3). The chattering period can be removed from the release touch count exactly as in the case of FIG.

[Effect of the Invention] As described above, the present invention provides a key depressing function even when two contacts of a key switch of a key are turned on and off in an abnormal state transition, and even when chattering occurs when the contacts are turned on and off, It is possible to measure an accurate touch count for a key release.

Therefore, even if inexpensive switches are used for the contact points B and M, a state where the key pressing speed and the key releasing speed cannot be measured does not occur, and a highly reliable electronic keyboard instrument can be provided.

In this embodiment, only one set of key switches is described for simplicity of description. However, by operating this embodiment in a time-division multiplexed manner, an initial touch count and a release touch count can be applied to a plurality of keys. An embodiment that can be measured is shown in FIG.

In this embodiment, the time measurement value and the discrimination signal sent from the output circuit 600 are sent to the memory 15 and the microcomputer 16, and the microcomputer 16 performs various controls using the key pressing speed and the key releasing speed. The following shows the case. Also, a case is shown in which a keyboard matrix 17 is provided to take out signals of the contacts B and M provided on a plurality of keys in a time-sharing manner.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining a polyphase pulse used in the embodiment of the present invention, and FIG. 3 is used in the embodiment of the present invention. 4 to 9 are waveform diagrams for explaining the operation of the present invention, and FIG. 10 is a block diagram showing a modification of the present invention.

Claims (1)

(57) [Claims] 1. A first switch and a second switch which are provided in connection with a key of a musical instrument and which are turned on and off with a time difference between when a key is pressed and released, and B. when the first switch and the second switch A discriminating signal generating means for performing a logical operation on a signal output in accordance with the on / off state of the two switches to output a discriminating signal indicating the key depressing process and the key releasing process; C. the first switch and the second switch A. Time signal generating means for outputting a time signal corresponding to the time difference between the ON and OFF operations of D. D. Time measuring means for measuring the length of the time signal output from the time signal generating means; An end signal generating means for outputting a signal indicating the end of the key release process, and F. receiving the end signal output by the end signal generating means, the determination signal output from the determination signal generating means and the time measuring means. The signal corresponding to the measured time An electronic keyboard musical instrument, comprising: an output circuit for taking in and outputting to the outside; G. a notification signal generating means for notifying to the outside that a new discrimination signal and a time measurement signal have been taken in to this output circuit. .