JPS648356B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an electronic musical instrument with a touch response function, and particularly to an electronic musical instrument having a sound generation assignment function of assigning pressed keys to a limited number of musical sound generation channels. The present invention relates to improvements in applying a method for obtaining key touch information by measuring the difference in actuation time between two key switch contacts corresponding to different key depression depths.

Prior Art Each key is equipped with two key switch contacts corresponding to different key depression depths, and by measuring the operating time difference between those two contacts independently for each key, each key is independently keyed. Techniques for detecting touches (initial touches) are already well known. On the other hand, polyphonic electronic musical instruments are equipped with a limited number of musical tone generation channels, which are sufficiently smaller than the total number of keys.
Key assigner (pronunciation assignment circuit) for the pressed key
It is now common practice to allocate appropriate signals to one of the channels according to the allocation, and to generate musical tone signals in each channel in accordance with this allocation. In order to measure the difference in the contact activation time for each key, in multitone electronic musical instruments, a limited configuration (i.e., a configuration corresponding only to each channel, not to all keys) corresponding to the assignment operation by the key assigner is used. It is advantageous to make use of a counting circuit. Such an electronic musical instrument is disclosed in Japanese Patent Publication No. 52-46088, and the concept of the touch count relationship therein is shown in a simplified manner as shown in FIG.

In FIG. 1, the keyboard circuit 10 includes a key switch KS including a break contact K1 and a make contact K2.
are arranged for each key. Brake contact K1 is always on and turns off when the key is depressed below a predetermined relatively shallow depth. The make contact K2 is always off, and is turned off when the key is depressed below a predetermined depth that is deeper than the operating depth of the break contact K1. Each key switch of the circuit 10 is sequentially and repeatedly scanned by the key scanning counter 11, and in response to this scanning output, the key press detection circuit 12 transfers the time-division multiplexed key data KD1, KD2 of each key to the break contact K1 and The respective outputs correspond to the make contact K2. For example, the first key data KD1 corresponding to the break contact is
The break contact K1 is "0" in the scan time slot of the key that is on, and is "1" in the scan time slot of the key that is off. Further, the second key data KD2 corresponding to the make contact is "0" in the scan time slot of the key where the make contact K2 is off, and is "1" in the scan time slot of the key where the make contact K2 is on.

The sound generation assignment circuit 13 is connected to the musical tone signal generation circuit 14.
Processing for assigning a pressed key to one of a plurality (N) of musical tone generation channels is performed based on the key data KD1, KD2 and the output of the key scanning counter 11. Various types of memory KAM,
BUM, KOM, and KFM are provided, which consist of shift registers having a number of stages corresponding to the number of channels N, for example. The control circuit 13a controls writing or clearing of each memory KAM to KFM according to the allocation operation. The key address memory KAM stores a multi-bit key code indicating the key assigned to each channel, and is written and cleared in response to writing and clearing of the busy memory BUM. The busy memory BUM stores whether or not a key is assigned to each channel. In the sound generation assignment circuit 13, when the first key data KD1 rises to "1", that is, when the break contact K1 turns off, the corresponding key assignment process is performed,
The busy memory BUM is set to "1" corresponding to the channel that has been determined to be allocated. For channels to which no keys are assigned (blank channels), the contents of the busy memory BUM are reset to “0”. For example, for channels whose BUM contents are “0” (blank channels),
It is decided to allocate a new pressed key for which KD1 has risen to "1", and based on this decision, "1" is set to the corresponding channel of BUM, and
A key code indicating the newly pressed key is stored in the corresponding channel of KAM. Key-on memory KOM
is for storing second key data KD2, and when the make contact K2 is turned on, "1" is stored corresponding to the channel to which the corresponding key is assigned. The key-off memory KFM stores "1" from the time the key is released until the end of the decay sound. For example, when the first key data KD1 switches from "1" to "0". In other words, when the break contact K1 is switched from OFF to ON, "1" is stored corresponding to the channel to which the corresponding key is assigned.
Although not specifically described, the allocation circuit 13 is further provided with circuits and memories for performing well-known truncate control and other necessary functions.

When the attenuation sound generation of the musical tone generated in each channel of the musical tone signal generation circuit 14 is completed, a decay end signal DF is applied to the sound generation allocation circuit 13 corresponding to that channel. This decay end signal DF causes the key-off memory KFM and busy memory corresponding to the channel in which the attenuation sound has ended.
The contents of BUM and key address memory KAM are reset (cleared). key on memory
The stored contents of KOM are reset with respect to the channel to which the corresponding key is assigned when the second key data KD2 falls to "0", that is, when the make contact K2 is switched from on to off.

The stored contents of each memory KAM to KFM are output in a time-division manner in synchronization with the time-division time slots of each channel. The musical tone signal generation circuit 14 receives information regarding the assigned keys of each channel sent out in a time-divisional manner from each of the memories KAM to KFM, and generates a musical tone signal in each musical tone generation channel based on this information. In other words, for each channel,
Key code KC from key address memory KAM
Based on this, a musical tone signal with a note name and octave determined according to the value of KC is generated, an envelope signal is formed according to the key-on signal KON from the key-on memory KOM and the key-off signal KOF from the key-off memory KFM, and this An amplitude envelope is given to the musical tone signal by an envelope signal.

The difference in operating time between break contact K1 and make contact K2 is determined by the busy signal BUS from busy memory BUM.
and key-on signal from key-on memory KOM
Measured using KON. key on signal
A signal obtained by inverting KON by the inverter 16 and the busy signal BUS are input to the AND circuit 15, and a signal TRS indicating the operating time difference between the two contacts by pulse width is output from the AND circuit 15 in a time-division manner for each channel. be done. As mentioned above, busy memory
The contents of BUM, that is, the busy signal BUS, rises to "1" when the break contact K1 is activated (switched to OFF), and the contents of the key-on memory KOM, that is, the key-on signal KON, rises to "1" when the make contact K2 is activated (switched to ON). ) rises to “1”.
Therefore, during the period from when the break contact K1 is turned off until the make contact K2 is turned on, that is, the pressed key moves from a predetermined first (shallow) depth to a second, deeper depth. During this time, the output signal TRS of the AND circuit 15 remains "1" corresponding to the time slot of the channel to which the key is assigned.

The touch counter 17 includes a multi-bit shift register 18 having a number of stages corresponding to the number of channels N, and a gate and an adder 19. A clear signal CC used to clear the contents of the busy memory BUM is drawn out from the sound generation allocation circuit 13 and used as a reset signal for the gate and adder 19. The contents of the shift register 18 are cleared to zero as described later in accordance with the channel in which the clear signal CC is generated. The output of the shift register 18 is returned to its own input side via a gate and an adder 19, and the clock pulse from the touch count clock pulse generator 21 is sent to the adder 19 via an AND circuit 20.
The value to be returned to the register 18 is incremented each time the register 18 is given, thus causing a count-up.
The shift register 18 is shift-controlled by two-phase system clock pulses φ _A and φ _B in synchronization with the time division timing of each channel in the sound generation allocation circuit 13 .
Touch counting operations for each channel are performed in a time-division manner. In the channel where the clear signal CC is generated, the gate and adder 19 stop the circulation of the output of the shift register 18, thereby clearing the contents of the register 18 to zero. Before the touch counter 17 counts the contact time difference for a certain channel, the contents of the shift register 18 for that channel are necessarily cleared to zero by the clear signal CC.

The AND circuit 20 is enabled by the output signal TRS of the AND circuit 15, and the count clock pulse of the generator 21 passes through the AND circuit 20 only during the time corresponding to the contact time difference, and the adder 19 given to. Therefore, during this time, the count value of the counter 17 gradually increases from zero at a constant rate (the rate of the count clock pulse), and when it finally reaches the count value corresponding to the contact time difference, the counting operation stops. do. That is, when the signal TRS falls to "0", the AND circuit 20 is disabled and no more count clock pulses are applied. Thereafter, the count value, that is, the contact time difference, that is, the touch data indicating the strength of key touch (pressing speed) is held in the shift register 18. Needless to say, this touch counting operation is performed independently and time-divisionally for each channel in accordance with the signal TRS for each channel that is generated time-divisionally. In addition, all “1”
The detection circuit 22 detects that all bits of the output of the shift register 18 have become "1", that is, the maximum value, and when this detection is made, it outputs "1" and changes the output of the inverter 23 to "0". to disable the AND circuit 20. As a result, all touch data corresponding to a contact time difference exceeding the maximum count value is limited to the maximum count value.

The touch data TD of each channel output from the shift register 18 in a time-divisional manner is given to the musical tone signal generation circuit 14, and the volume, tone, pitch, and modulation of the musical tone signal to be generated in the corresponding channel in the circuit 14 are applied. Used to control musical tone elements such as effects and envelopes. The output musical tone signal of the musical tone signal generation circuit 14 is given to a sound system 24.

Problems with the Prior Art In the prior art as described above, the detection resolution of a key touch depends on the resolution of the signal TRS indicating the contact time difference, that is, the minimum possible time width. This depends on the minimum time interval during which data can be rewritten regarding the same key, which in turn depends on the period of one scanning cycle of the key in the keyboard circuit 10. In other words, from when break contact K1 for a certain key is detected to be off (when the busy signal BUS rises) to when make contact K2 for that key is detected to be on (key on signal
(up to the rise of KON) requires a time interval corresponding to at least one scan cycle period, and cannot respond to faster changes, that is, contact time differences. In this way, the key touch detection resolution is determined by the length of one scanning cycle period of the key. In order to improve the resolution of the touch response, it is better to make the key scanning cycle as short as possible. However, in the above-mentioned prior art, the length of the key scanning cycle is related to the time division period of each channel in the tone generation allocation circuit 13, and this is
4, the key scanning cycle is controlled by the musical tone generation period and cannot be made too short. Typically, the scanning time for one key (one time slot of key data KD1, KD2) corresponds to one cycle of time-division channel time in the sound generation assignment circuit 13, and this one cycle period is divided by the number of channels N. A time slot is provided for each channel. Sound allocation circuit 13
The time division channel time directly corresponds to the time division channel time of the musical tone signal generation circuit 14. The musical tone generation calculation speed for one sample point in the musical tone signal generation circuit 14 (this calculation includes not only simple calculation but also memory reading, etc.) has its own limit, and the scanning time for one key ( Conventionally, this corresponds to one sampling period of a musical tone), and therefore, the key scan 1 consists of the scanning time for one key, which is generally multiplied by the number of keys.
The length of the cycle was also determined by the limit of musical sound generation calculation speed, and could not be made too short. Thus, in conventional electronic musical instruments, one key scanning cycle is set to, for example, about 3 mm. However, it has been confirmed that when the touch is most effective during actual key performance, the contact time difference is much shorter than that, for example, about 0.5 milliseconds, and conventional electronic musical instruments It was unable to respond to repeated key touches.

Another problem is that in the conventional electronic musical instrument as described above, the assignment is made based on the operation of the first contact (the break contact K1 is turned off), and this assignment is directly related to the sound generation channel of the musical tone signal generation circuit 14. As a result, the following problems arose. In other words, when a slight downward movement of the key occurs due to a key press error or vibration, the first contact is activated, and assignments are made based on this, so that the sounding channel is occupied by a key that does not actually sound. There was a risk that this would cause trouble when the actual key to be pressed should be assigned.

Purpose of the Invention The present invention has been made to overcome the drawbacks of the above-mentioned prior art.Firstly, the purpose is to increase the detection resolution of a key touch, and secondly, the first purpose is to improve the detection resolution of a key touch.
It is an object of the present invention to prevent meaningless interruptions of a musical tone generation channel from occurring when only the contacts of the toner malfunction.

Summary of the Invention The electronic musical instrument according to the present invention includes a first contact point and a second contact point provided for each key that operate sequentially at different key pressing depths, and a first contact point and a second contact point of each key.
a key press detection means for detecting activation of a contact point; and a first key detecting means for detecting activation of a contact point of the key press, and a first key detecting means for allocating the pressed key to one of a predetermined number of channels in response to activation of the first contact point accompanying the press of each of the keys. allocating means, and said first
According to the assignment by the assigning means, for each channel, the difference in operating time from when the first contact is activated to when the second contact is activated regarding the key assigned thereto is measured, and the measurement result is touch detection means that uses as touch data; a second assigning means for assigning and outputting information specifying the assigned key and the touch data regarding the key detected by the touch detecting means in correspondence with the assigned musical tone generation channel; and each of the musical tones. The present invention is characterized in that it includes musical tone generating means for generating a musical tone signal for each generation channel in accordance with the information and the touch data corresponding to the musical tone generation channel.

When the first contact point is actuated as a result of pressing a key, the first assigning means responds to this by assigning the pressed key to one of a predetermined number of channels. In the touch detection means, in accordance with the assignment by the first assignment means, the touch detection means operates for each channel from the activation of the first contact point to the activation of the second contact point related to the key assigned thereto. Measure the time difference and use the measurement results as touch data.

When the second contact is actuated with respect to the key assigned to each channel by the first assignment means, in response, the second assignment means assigns the key to one of a predetermined number of musical sound generation channels. and outputs information specifying the assigned key and the touch data regarding the key detected by the touch detection means in correspondence with the assigned tone generation channel. The musical sound generation means generates a musical sound signal for each musical sound generation channel in accordance with the information and the touch data outputted corresponding to the musical sound generation channel.

In this way, key touch detection is performed for each channel with respect to the keys assigned thereto according to the assignment by the first assignment means. Since this first allocation means is provided separately from the second allocation means for allocating to musical sound generation channels, the processing operation time in the first allocation means is limited by the calculation time of the musical sound generation channels. It is possible to operate at high speed without being affected by Therefore, the detection resolution of key touches can be improved. Furthermore, in the second allocation means,
In response to the operation of the second contact regarding the key assigned to each channel by the first assignment means, the assignment process of the key to the musical tone generation channel is performed, so if only the first contact malfunctions, the musical tone is generated. Allocation processing for channels is not performed, and meaningless occupancy of musical sound generation channels does not occur.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In Fig. 2, the parts indicated by the same symbols as in Fig. 1 are the same, and the explanation thereof will be omitted below.
Reference is made to the explanation already given with reference to FIG. The first to which the output of the key scanning counter 11 and the output key data KD1, KD2 of the key press detection circuit 12 are given.
The key address memory KAM, busy memory BUM, and control circuit 25a shown in the allocation circuit 25 of
The functions of KAM, BUM, and 13a in Fig. 1 also roughly correspond, and some of the explanations for these already mentioned will be used.

The first assignment circuit 25 is for assigning a pressed key to a predetermined number (M) of channels in response to the key scanning results given from the pressed key detection circuit 12 and the key scanning counter 11. Although it corresponds to the channel of the counter 17, it does not directly correspond to the musical tone generation channel in the musical tone signal generation circuit 14. In response to the allocation result of the first allocation circuit 25, the second allocation circuit 26 assigns a predetermined number ( N), and the touch data TD obtained by the touch counter 17 is allocated to each musical tone generation channel corresponding to this reallocation.

Shift register 18 of touch counter 17, key address memory in first allocation circuit 25
KAM, busy memory BUM, key-on event memory KOEM, key-off event memory KFEM
have the same number of stages (M) as the number of channels (M) processed by the first allocation circuit 25, respectively.

First, to explain the assignment operation of the first assignment circuit 25, as described above, when the first key data KD1 rises to "1", that is, when the break contact K1 turns off, the corresponding key is assigned. Processing is performed, and the busy memory BUM is set to "1" corresponding to the channel that has been determined to be allocated, and the key address memory is set to "1".
A key code corresponding to the scanning timing of the key data KD1 is stored in KAM. However, when determining the allocated channel, there is no need for complicated processing such as truncation processing, and the condition is that the same key code is not yet stored in KAM.
The above determination may be made for one blank channel indicated by BUM. Memory BUM,
The data stored in KAM is cleared when the corresponding key is released, that is, break contact K1
This can be done when KD1 returns to on (when KD1 becomes "0").

The key-on event memory KOEM is for storing that the second contact, that is, the make contact K2, has been turned on. When the make contact K2 of a certain key is turned on, a signal "1" is given from the control circuit 25a at the timing of the channel to which that key is assigned, and the signal is sent to the shift register 28 via the OR circuit 27.
is memorized. The output of the shift register 28 is circulated and held via an AND circuit 29 and an OR circuit 27. The key-on event pulse generating circuit 30 is for providing a key-on event pulse KOEVN to the second assignment circuit 26 in response to switching of the second contact K2 from off to on. A clear signal is applied to the key-on event memory KOEM in response to the key-on event pulse KOEVN, thereby disabling the AND circuit 29. Therefore,
When the key-on event pulse KOEVN is issued, the corresponding key-on event memory
KOEM's memory is cleared. The R-S flip-flop 31 is reset to "0" when the second assignment circuit 26 is processing a key-on event, and is set to "1" at other times. This set output is applied to the AND circuit 32, which selects the output "1" of the key-on event memory KOEM on the condition that the second assignment circuit 26 is not processing a key-on event. The output "1" of this AND circuit 32 becomes the key-on event pulse KOEVN.
This output “1” is output by the delay flip-flop 33.
It is delayed by the channel timing and applied to the reset input of the R-S flip-flop 31.
Thus, one key-on event pulse
When KOEVN occurs, flip-flop 31 is reset, AND circuit 32 is disabled, and
Generation of the next key-on event pulse is suppressed. When the second allocation circuit 26 completes the allocation process according to the key-on event pulse KOEVN, a key-on event end signal END1 is output, and the flip-flop 31 in the key-on event pulse generating circuit 30 is set. thus,
AND circuit 32 is enabled and the next key-on event pulse can be generated.

The key-off event memory KFEM is for remembering that the key has been released, and is activated in the corresponding channel in response to the switching of the make contact K2 from on to off or the switching of the break contact K1 from off to on. This memory stores “1”
KFEM is configured similarly to the memory KOEM described above. Key-off event pulse generation circuit 34
generates a key-off event pulse KFEVN based on the output of the key-off event memory KFEM, and is configured similarly to the key-on event pulse generating circuit 30 described above. A key-off event pulse is generated in the second assignment circuit 26.
When the processing corresponding to KFEVN is completed, a key-off event end signal END2 is output, and an R-S flip-flop (not shown) in the key-off event pulse generation circuit 34 is set. Further, the key-off event memory KFEM is cleared by the key-off event pulse KFEVN as described above.

The output of the key-on event memory KOEM is applied to an AND circuit 15 via an inverter 16. The other inputs of the AND circuit 15 have busy memory.
The output of BUM is given. Similarly to the above, at each channel timing, the AND circuit 15
The output TRS of becomes “1”. Therefore, as in FIG. 1, the touch counter 17 can count the difference in operating time between two contacts.

By the way, since the first allocation circuit 25 is not directly related to the musical tone signal generation circuit 14, it is possible to operate at high speed without being limited by the musical tone generation calculation time. Therefore, the clock pulses φ ₁ and φ ₂ that set the time division channel timing in the first allocation circuit 25 and the touch counter 17 are faster than the clock pulses φ _A and φ _B that set the time division channel time in the second allocation circuit 26. It can be much faster.
As the clock pulses φ ₁ and φ ₂ become faster,
The period of one key scanning cycle is shortened, and it becomes possible to sufficiently respond to high-speed key touches.

The key-on event pulse KOEVN, the key-off event pulse KFEVN, the key code KC from the key address memory KAM, and the touch data TD from the touch counter 17 are applied to the second assignment circuit 26, which are output from the first assignment circuit 25. The second allocation circuit 26 is the first allocation circuit 2
5 is asynchronous, so the event pulse
Processing is performed using KOEVN and KFEVN.

The second allocation circuit 26 includes a key code memory KCM, a key-on memory KONM, a busy memory BUSM, a touch data memory TDM, etc. corresponding to the N musical tone generation channels, and includes a key code memory KCM, a key-on memory KONM, a busy memory BUSM, a touch data memory TDM, etc. The control circuit 26a performs the reallocation process based on the data.
is operated, and storage in each memory is controlled by this control circuit 26a. Then, according to the time division timing of each musical tone generation channel set by clock pulses φ _A and φ _B , the key code KC′ of the key assigned to each channel and the key-on signal are
KON′, Touch Data TD′ are each memory KCM~
The signal is read from the TDM and applied to the musical tone signal generation circuit 14.

The assignment operation of the second assignment circuit 26 (that is, the operation of the control circuit 26a) can be performed using a microcomputer. In that case, in the second allocation circuit 26, the key-on event pulse KOEVN, the key-off event pulse
Processing in response to KFEVN and Decay end signal DF is performed as interrupt processing.

When the key-on event pulse KOEVN is applied, a key-on event routine as shown in FIG. 3 is performed. First, in block 35, the key code KC given from the first allocation circuit 25 at the same time as the key-on event pulse KOEVN is temporarily stored in the area of the input key code register KCODE of the internal RAM of the microcomputer, and the touch data TD given at the same time is stored. is temporarily stored in the input touch data register TDATA area of the RAM.

An example of the memory map of this RAM is shown in FIG. CHN is a channel number cylinder for key-on event processing, and K is a channel number register for key-off event processing.
KCM1 to KCM12 are key code registers corresponding to each tone generation channel, and the numbers in brackets indicate channel numbers, and in this example, the number of channels is N=12. KONM1～KONM1
2 is key-on register, BUSM1 to BUSM12
is a busy register, and TDM1 to TDM12 are touch data registers, each of which corresponds to each tone generation channel.

Returning to FIG. 3, block 36 registers the busy register BUSM (CHN) corresponding to the channel specified by the channel number register CHN.
Pull out the contents of and check whether it is "0". If NO, block 37 increments the CHN channel number by 1, and block 38 checks whether this loop has been repeated N (ie, 12) times. If NO, return to block 36 and BUSM(CHN) again for the channel number incremented by 1.
=0? Find out. If the channel specified by CHN is blank, block 36 becomes YES and the process proceeds to block 39, where the key code register corresponding to the channel specified by CHN is entered.
Input key code register KCODE to KCM CHN
Memorize the key code KC and set the corresponding key-on register KONM CHN and busy register BUSM.
"1" is stored in each CHN, and the touch data TD of the input touch data register TDATA is stored in the corresponding touch data register TDM CHN.
The next block 40 increments the CHN channel number by one. After outputting the key-on event end signal END1 in the next block 41, the program returns to the main program.

If all channels have been allocated, block 38 becomes YES when the loop of blocks 36-38 is repeated N times (12 times). In that case, block 42 performs truncation processing. In other words, among the key-on registers KONM1 to KONM12, the one whose content is "0" (key being released) and the corresponding musical tone signal amplitude value is small or the one whose key was released the earliest satisfies a predetermined truncation condition. designate it as a truncated channel and assign a new press key to that channel.
In the next block 43, similar to block 41, a key-on event end signal END1 is output.
In this way, the second allocation circuit 26 sends out the key-on event end signal END1 every time one key-on event routine is completed, and the first allocation circuit 25 sends out the next key-on event pulse KOEVN.
It becomes possible to generate.

When the key-off event pulse KFEVN is applied, a key-off event routine as shown in FIG. 4 is performed. In block 44, the first assignment circuit 2 is activated simultaneously with the key-off event pulse KFEVN.
The key code KC given from 5 is stored in the input key code register KCODE. Next, channel number register K is set to "1" (block 45). In block 46, the stored key code is retrieved from the key code register KCMK corresponding to the channel number specified by the register K, and it is compared with the key code of the input key code register KCODE to see if they match. . If NO, the channel number in register K is incremented by 1 (block 47), and then it is checked whether K=12 (that is, N) (block 48). If block 48 is NO, the process returns to block 46. When the value in register K indicates the channel to which the released key code is assigned, block 46 is activated.
YES, and in block 49, the contents of the corresponding key-on register KONMK are cleared to "0". In the next block 50, a key-off event end signal END2 is output. Generally, block 48 will not be YES, but this
If YES, block 51 outputs a key-off event end signal END2.

Decay end signal from musical tone signal generation circuit 14
When DF is given, execute the Decay termination routine. Although not particularly shown in the drawings, this Decay end routine is executed in a similar manner to the key-off event routine shown in FIG. In other words, find the channel to which the Decay end signal DF is given,
Busy register corresponding to this channel
Clear the contents of BUSM1 to 12 to “0”.

RAM registers KCM1 to 12, KONM1
-12, BUSM1-12, and TDM1-12 are transferred to the output memories KCM, KONM, BUSM, and TDM, and are output in a time-divisional manner according to clock pulses φ _A and φ _B.

Note that the key switch corresponding to each key is not limited to one having a break contact and a make contact as described above, but a two-stage key switch such as that shown in Japanese Patent Application Laid-Open No. 139521/1982 may also be used. In short, it is sufficient that each key has two contacts that operate at different pressing depths.

Effects of the Invention As described above, according to the present invention, the first assignment means for key touch detection is provided separately from the second assignment means for assigning to musical sound generation channels, and the first assignment means performs the assignment. Therefore, for each channel, the contact activation time difference for key touch detection is measured for the keys assigned to it, so that the processing operation time in this first assignment means is equal to the calculation time for the musical sound generation channel. This has the excellent effect of being able to operate at high speed without being limited by time, and therefore increasing the detection resolution of key touches. Furthermore, the second assigning means performs the process of assigning the key to the musical sound generation channel in response to the operation of the second contact regarding the key assigned to each channel by the first assigning means. If only the contact malfunctions, the assignment process to the musical sound generation channel will not be performed.
This has the excellent effect of preventing meaningless occupation of musical sound generation channels.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional technology of a multitone electronic musical instrument that performs a key touch counting operation for each channel, FIG. 2 is a block diagram showing an embodiment of an electronic musical instrument according to the present invention, and FIG. FIG. 4 is a flowchart showing an example of a key-on event routine executed in the second allocation circuit shown in the figure; FIG. 4 is a flowchart showing an example of a key-off event routine executed in the second allocation circuit shown in FIG. Second
FIG. 2 is a diagram showing an example of a memory map of a RAM of a microcomputer used as an allocation circuit. 10...Keyboard circuit, KS...Key switch, K
1...Break contact (first contact), K2...Make contact (second contact), 11...Key scanning counter, 12...Key press detection circuit, 17...Touch counter, 25...First allocation circuit, 26...second
assignment circuit, KAM...key address memory,
BUM...Busy memory, KOEM...Key-on event memory, KFEM...Key-off event memory.

Claims (1)

[Scope of Claims] 1. A first contact and a second contact provided for each key that operate sequentially at different key depression depths; a key press detection means for detecting a pressed key; and a first assignment means for allocating the pressed key to one of a predetermined number of channels in response to activation of the first contact in response to the pressing of each of the keys; According to the assignment by the first assigning means, for each channel, the first contact associated with the key assigned thereto is actuated and then the second
touch detection means for measuring the difference in operating time until the contacts are actuated and using the measurement result as touch data; In response, the key is assigned to one of a predetermined number of musical tone generation channels, and the information identifying the assigned key and the touch data regarding the key detected by the touch detection means are transferred to the assigned musical tone generation channel. The second output corresponding to
and musical tone generating means for generating a musical tone signal for each of the musical tone generating channels according to the information and the touch data corresponding to the musical tone generating channel. 2. The electronic musical instrument according to claim 1, wherein the first assignment means performs assignment processing at a higher speed than the second assignment means.