JP3396939B2 - Touch detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch detection device suitable for use in an electronic musical instrument such as an electronic piano.

[0002]

2. Description of the Related Art As is well known, in electronic musical instruments such as electronic pianos, key scanning for detecting a key pressing operation is performed, and a key pressing touch or a key pressing operation is performed based on key pressing information obtained by the key scanning. Many are equipped with a touch detection device that detects an aftertouch. This type of device scans a key switch matrix provided for each key and generates a note number, a touch (velocity) and a key release signal corresponding to a key-on / key-off event obtained thereby. Usually, each key is provided with a first and a second key switch, and when the key is pressed, the first key switch is turned on, and subsequently, the second key switch is turned on. When releasing the key, the first key switch is turned off after the second key switch is turned off.
Therefore, in the touch detection device, the key touch is performed by measuring the switch timing at the time of key depression, that is, the time interval from the time when the first key switch is turned on to the time when the second key switch is turned on. The data corresponding to (velocity) is generated.

[0003]

In the above-mentioned conventional touch detection device, each time the key-on / key-off event occurs, the above-mentioned various key press / release information is generated, and this is sent to the CPU side which controls each part of the musical instrument. To supply,
When a plurality of events occur continuously, it may happen that the transfer to the CPU cannot be completed within a certain time. Therefore, in order to deal with such a case, the touch detection device is provided with an event buffer memory for storing key release information for each event.

By the way, the event buffer memory requires a relatively large storage capacity, and when mounted on an inexpensive electronic musical instrument, in view of cost performance, it may be a factor of increasing the product cost. In order to realize touch detection without using the event buffer memory, it is conceivable to measure the period during which the first and second key switches are in the ON state in sequence and hold the measured value until it is read by the CPU. For example, as shown in FIG. 10, at time t ₀ , the key is pressed to turn on the first key switch S1, and then at time t ₁ , the second key switch S1 is turned on.
When the key switch S2 is turned on, the count value measured during the time t _{0 to} t ₁ becomes the value corresponding to the key pressing touch, and this is transferred to the CPU after the elapse of a predetermined time.

However, in such a system,
Before transferring the detected touch information to the CPU side,
When an event occurs, the touch information detected first is C
Touch information corresponding to the next event after transferring to PU
Is detected, the measurement start timing is
Detected incorrect touch information due to deviation from the point of occurrence
There is a problem of doing. For example, as shown in FIG.
Time t₂~ T₃Key release touch corresponding to
While waiting to transfer to PU, time t 4 odors
When the next key-on event occurs,
The corresponding measurement start timing is delayed by Δt, resulting in
Erroneous key press touch is detected, which causes unnatural
This causes an adverse effect that a musical sound is formed. Book there
The invention has been made in view of the above circumstances, and has a large capacity.
Accurate touch information without using the event buffer of
To provide a touch detection device that can detect
Has an aim.

[0006]

In order to achieve the above-mentioned object, in the invention described in claim 1, the first and the second keys are provided for each key and are turned on and off sequentially in response to a key pressing operation. A key press or key release is detected according to the on / off states of the second key switch and the first and second key switches, and state information representing a key press event or a key release event is generated, and the first and second key switches are generated. The touch information generating means for generating touch information corresponding to the on / off timing of the second key switch, the temporary storage means for temporarily storing the state information and the touch information, and the touch information stored in the temporary storage means when in the read wait state from the outside, when the touch information generating means detects a new key depression or key release, corresponding to key depression or before release key before related to the detected key It is characterized by comprising control means for disabling the status information and touch information.

According to the second aspect of the present invention, the status information includes at least information for identifying either key depression or key release, and information for identifying completion or incompleteness of key depression or key release. It is characterized by being formed from. Further, according to the invention described in claim 3, the temporary storage means stores the state information and the touch information in a storage area corresponding to each of the keys.

[0008]

According to the present invention, when the first and second key switches are sequentially turned on and off in response to the key pressing operation, the touch information generating means responds to the on and off states of the first and second key switches. Key depression or key release is detected, state information representing a key depression event or a key release event is generated, and touch information corresponding to the on / off timing of the first and second key switches is generated. Then, the temporary storage means temporarily stores the state information and the touch information, and when the touch information stored in the temporary storage means is in a standby state for being read out from the outside, the touch information generation means makes a new key press. Alternatively, when the key release is detected, the control means invalidates the state information and the touch information corresponding to the previous key depression or the previous key release. As a result, accurate touch information can be detected without using a large capacity event buffer.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. A. Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of a touch detection device according to an embodiment of the present invention. In this figure, 1 is a controller for controlling each part of the apparatus, and its operation will be described later. A decoder (DEC) 2 decodes the scan signal Sc supplied from the controller 1 and outputs a signal KC. Reference numeral 3 denotes a switch matrix in which key switches SW provided for each key are connected in a matrix, and a signal KI corresponding to a key depression or key release is generated. Here, the configuration of the switch matrix 3 will be described with reference to FIG. The switch matrix 3 shown in this figure includes key switches SW arranged in 8 rows and 22 columns. One end of each of these key switches SW is connected to a signal KC line, and the other end is pulled up via a diode D.

Of the key switches SW arranged in 8 rows and 22 columns, two keys adjacent to each other in the column direction are paired to form one key KEY.
Is installed in. That is, as shown in FIG. 3, the key KEY
Below the key, two key switches SW are provided, and these two key switches SW are hereinafter referred to as switch S1 and switch S2. Therefore, in the matrix circuit shown in FIG. 2, when the row number is “i (i = 0 to 7)” and the column direction set number is “j (j = 0 to 10)”, each key K is
EY is represented by array element (i, j). The switches S1 and S2 are turned on first when the key is pressed, and then the switch S2 is turned on. On the other hand, when the key is released, the switch S2 is turned off and then the switch S1 is turned off.

Next, the configuration of the embodiment will be described again with reference to FIG. A key-in register (KIR) 4 temporarily stores the signal KI output from the switch matrix 3 for each key. Reference numeral 5 denotes a memory in which touch information for each key is read / written according to a control signal supplied from the controller 1. When the memory 5 corresponds to, for example, the 88-key specification, as shown in FIG. 5, the touch information of 1 byte (8-bit length) is stored for each key. The touch information mentioned here is formed of a 63-step touch count value VC expressed by lower 6 bits, a flag F1 (1 bit) and a flag F2 (1 bit) described later. In the following description of the operation, the storage area of the touch count value VC is referred to as register VC (n), and n
Represents a key number. Unlike the conventional key buffer, this memory 5 temporarily stores the touch count value VC measured every time a key release event occurs, the flag F1 and the flag F2, and has a storage capacity of 88 key specifications. It has a very small capacity of 88 bytes.

A memory register 6 temporarily stores touch information of the corresponding key read from the memory 5 in response to a control signal. Reference numerals 7 and 8 denote set / reset circuits that set / reset flags F1 and F2 read from the memory register 6 in accordance with a control signal. Reference numeral 9 is an increment counter which is set / reset according to a control signal. An inverter 10 bit-inverts the touch count value VC output from the memory register 6 to generate a velocity VL. Reference numeral 11 is a velocity register for temporarily storing the velocity VL. 12
Is a note register for temporarily storing the note number NT and the flag F2 supplied from the controller 1.

The velocity VL and the note number NT stored in these registers 11 and 12 are shown in FIG.
It consists of 1 byte as shown in (a) and (b), and is read by the CPU 20 in the subsequent stage. The contents of the registers 11 and 12 are reset to zero by the reset signal S _R supplied from the controller 1. Thirteen
Is a flag register that is accessed by both the CPU 20 and the controller 1, and is a set / reset flag RDY that is exchanged between the CPU 20 and the controller 1.
Is temporarily stored. The CPU 20 resets the flag RDY to "0" when the contents of the registers 11 and 12 are read.

B. Operation of Embodiment Next, the operation of the embodiment having the above configuration will be described with reference to FIGS.
Will be described with reference to. Operation of Main Routine First, when the power is turned on in this embodiment, the controller 1 reads the microprogram preset in itself and executes the main routine shown in FIG.
The process proceeds to A1. At Step SA1, it is judged whether or not the value of the register i for storing the above-mentioned line number i exceeds "7". That is, it is determined whether or not the signal KC output from the decoder 2 has completed the scanning of the row lines.
Here, if the scanning has completed one cycle, the determination result is "YE
S ”, the process proceeds to step SA2, the line number i is reset to zero, and then the process returns to step SA1.

When the scan of the row line is updated in this way,
The determination result in step SA1 is “NO”, and the process proceeds to step SA3. In step SA3, it is determined whether or not the value of the register j that stores the column set number j exceeds "10". That is, it is determined whether or not the scanning in the column direction has completed one cycle. Here, when the scanning has completed one cycle, the determination result is “YES”, and the process proceeds to step SA4. In step SA4, the value of the register i is incremented by 1 to advance, while the value of the register j is reset to zero,
The process returns to step SA1 again. As described above, in steps SA1 to SA4, the matrix circuit shown in FIG. 2 performs row line scanning for sequentially supplying the signal KC to the row numbers 0 to 7, and the switches S1 arranged on the key KEY.
The S2 set is scanned in the order of column set numbers 0-10.

In the process of scanning the switch sets S1 and S2 in the order of the column set numbers 0 to 10, the above step S is performed.
The determination result of A3 is "NO", and the controller 1 advances the processing to step SA5. In step SA5, the key number n currently being scanned is calculated and stored in the register n. The key number n is obtained by substituting the current row number i and column set number j into the equation (8j + i). In step SA5, the decoder (DEC) 2
The value of the register i is set in the register, and the output signal KI of the switch matrix 3 is set in the register (KIR) 4. As a result, the switch state of the currently scanned key is detected.

Next, in step SA6, it is determined whether or not a flag F1 (n) indicating completion / incompletion of key depression or key release is "1". This flag F1 (n) is
As shown in FIG. 5, it is a flag stored in the memory 5. When the flag is "1", it indicates that the key is released, and when it is "0", it indicates that the key is being released. . Here, if the key release is completed, the determination result is "YE
S ”, the process proceeds to step SA7, the register processing routine described later is executed, and the velocity register 11 and the note register 12 have velocity VL and note number N.
T and flag F2 are set respectively. On the other hand, if the key is being released, the determination result is "NO", the flow proceeds to step SA8, and memory processing described later is executed.
Then, after this, when the process proceeds to step SA9, the register j
Is incremented by 1 to advance the column group number, and the process returns to step SA3 described above.

Operation of Memory Processing Routine Next, the operation of the memory processing routine will be described with reference to FIG. As described above, when a key being pressed and released is detected by the key scanning, the memory processing routine is executed via step SA8, and the controller 1 executes step S8.
The process proceeds to B1. In step SB1, the signal KI set in the key-in register (KIR) 4, that is, the switches S1 arranged for the key-scanned key KEY.
The switch signal representing the state of S2 is inverted and stored in the registers FI and SI. Here, the switches S1,
The signal KI corresponding to S2 is stored in the storage areas KIR (2j) and KIR (2j + 1) of the key-in register 4. In addition, "!" In the figure means inversion. The signal KI corresponding to the switches S1 and S2
Is pulled up, it becomes "1"("H" level) in the key-off state and "0" in the key-on state.
(“L” level).

Next, at step SB2, it is determined whether the flag F2 (n) is "1", that is, whether the previous event is key depression. Here, if the previous event is key depression, the determination result is "YES" and the process proceeds to step SB3. At step SB3, the register FI,
The signal KI stored in SI is inverted, and
Inverted value of register FI to register SI, register SI
Stores the inverted value of No. to the register FI, and the next step SB
Go to 4. On the other hand, if the previous event was key release, the determination result of step SB2 is “NO”,
Go to step SB4. In step SB4, it is determined whether the value of the register FI is "1", that is, whether the key depression or key release is started. Here, when the key depression or key release is started, the determination result is “YES”, and the process proceeds to step SB5. In step SB5, the touch count value VC stored in the register VC (n) is "3.
Fh (hexadecimal number display) ", that is, whether or not it corresponds to the maximum count value is determined. If it corresponds to the maximum count value, the process proceeds to step SB7, which will be described later. On the other hand, if not, the determination result is “NO” and the process proceeds to step SB6. In step SB6, the touch count value VC stored in the register VC (n) is set to 1
Increment and count up, step SB7
Go to.

In step SB7, it is determined whether the value of the register SI is "1", that is, whether key depression or key release is completed. Here, when the key depression or key release is completed, the determination result is “YES”, and the next step SB
The process proceeds to 8. On the other hand, when the value of the register SI is "0", it is determined that the key depression or key release is not completed, and the determination result is "NO", and this routine is ended. In step SB8, the flag F1 (n) indicating the completion / non-completion of the key release is set to "1" to indicate that the key depression or key release is completed, and the flag F2 (n) is inverted. The flag F2 (n) represents a key depression by "1" and a key release by "0".

On the other hand, in step SB4 described above,
If the key depression or key release is not started, the determination result here is "NO" and the process proceeds to step SB9. In step SB9, it is determined whether or not the touch count value VC stored in the register VC (n) is "0". If the count value VC is "0", it is considered that the corresponding key has not been pressed and released, and this routine is ended. On the other hand, when the count value VC is not "0", that is, the register FI is "1" and the register S
Touch measurement is performed from the time when I becomes “0”, and when both the registers FI and SI become “0” from this state,
The value of the register VC (n) is reset on the assumption that a halfway press release operation or key release operation is performed, and this routine is ended.

Operation of Register Processing Routine Next, the operation of the memory processing routine will be described with reference to FIG. When the flag F1 (n) is set to "1" by the memory processing routine described above and the pressing or releasing of the key is completed, the controller 1 causes the controller 1 to execute step SA7 (see
Register processing routine), and the process proceeds to step SC1. In step SC1, the signal KI set in the key-in register (KIR) 4, that is, the switch signals of the switches S1 and S2 arranged in the corresponding key is inverted, stored in registers FI and SI, and Go to step SC2. At step SC2, whether or not the flag F2 (n) is "1", that is,
Determine if the last event was a key press. Here, if the previous event is key depression, the determination result is "YES", and the process proceeds to step SC3. Step S
At C3, the signals KI respectively stored in the registers FI and SI are inverted, the inverted value of the register FI is stored in the register SI, the inverted value of the register SI is stored in the register FI, and the process proceeds to the next step SC4.

On the other hand, in step SC2, if the previous event was key release, the determination result is "N".
"O" and the process proceeds to step SC4. In step SC4, it is determined whether the set / reset flag RDY stored in the flag register 13 is "1". Here, when the CPU 20 side has completed reading the velocity register 11 and the note register 12, the determination result is "NO", and the process proceeds to step SC5. In step SC5, the flag F2 (n) and the note number NT
Are stored in the note register (NR) 12, and the inverted value (velocity VL) of the register VC (n) is stored in the velocity register (VR) 11. Further, the flag F1 (n) is set to "0" and the flag register 13 is set to "1".
This routine is finished by resetting (n) to zero.

On the other hand, when the reset signal SR is not supplied from the CPU 20 side, the set / reset flag RDY is "1", so the above step SC4.
The result of the determination is "YES", and the process proceeds to step SC6. At step SC6, the value of the register FI is "1",
That is, it is determined whether or not the key depression or key release is started. If neither is started, the determination result is "NO", and this routine is completed. on the other hand,
When the key press or key release is started, the judgment result is "Y
ES ”, and then the process proceeds to step SC7. Step S
In C7, the flag F1 (n) is set to " 0 ", the flag F2 (n) is inverted, and the register VC (n) is inverted.
Is reset to zero and this routine ends.

Specific Operation Next, with reference to FIG. 9, a specific operation achieved by each of the above-described routines will be described. First, it is assumed that a key depression event occurs at time t ₀ , touch measurement is performed from this time to time t _1, and the velocity VL corresponding to the measured touch count value VC is read to the CPU 20 side at time t ₂ . Then, when the key release event occurs at time t _3, switch S1 from time t ₃ in memory processing routine described above is between time t ₄ when turned off, key release touch is measured. Here, for example, register 1
When the CPUs 1 and 12 are in a waiting state for reading from the CPU 20, the determination result of step SC4 (see FIG. 8) in the above-described register processing routine (see FIG. 8) is “YES”.
Then, the process proceeds to step SC6.

Then, if there is a next key press at time t ₅ before the processing of the controller 1 proceeds to step SC6, the determination result at step SC6 becomes "YES", and the routine proceeds to step SC7. In step SC7, as uniquely "1" flag F1 (n), forced with complete the key release event occurring at time t _3,
In this time t ₅ so as to correspond to the newly initiated depressed event by inverting the value of the flag F2 (n), represent that last event is key release. And register VC
(N) is reset to zero. As a result, the key release touch measured between time t ₃ and time t ₄ is canceled. Therefore, according to this embodiment, the measurement start timing corresponding to the next event is not delayed due to the waiting for reading as in the conventional case, and an adverse effect such as the formation of an unnatural musical tone based on incorrect touch information is prevented. It is possible to prevent it. Moreover, in the present embodiment, accurate touch information can be detected without using a large-capacity event buffer as in the conventional case, so that the product cost is not increased.

[0027]

According to the present invention, when the first and second key switches are sequentially turned on / off in response to a key pressing / release operation, the touch information generating means turns on / off the first and second key switches. In response to the key press or key release, state information representing a key press event or a key release event is generated, and touch information corresponding to the on / off timing of the first and second key switches is generated. Then, the temporary storage means temporarily stores the state information and the touch information, and when the touch information stored in the temporary storage means is in a standby state for being read out from the outside, the touch information generation means makes a new key press. Alternatively, when the key release is detected, the control means invalidates the state information and the touch information corresponding to the previous key press or the previous key release. Therefore, accurate touch information can be detected without using a large capacity event buffer. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a touch detection device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a switch matrix 3 in the embodiment.

FIG. 3 is a cross-sectional view showing a switch S1 and a switch S2 arranged below a key KEY.

FIG. 4 is a diagram for explaining a data structure of a velocity VL and a note number NT stored in registers 11 and 12 in the same embodiment.

FIG. 5 is a diagram for explaining a storage area of a memory 5 in the same embodiment.

FIG. 6 is a flowchart for explaining the operation of the main routine in the embodiment.

FIG. 7 is a flowchart for explaining the operation of a memory processing routine in the same embodiment.

FIG. 8 is a flow chart for explaining the operation of a register processing routine in the embodiment.

FIG. 9 is a diagram for explaining a specific operation of the embodiment.

FIG. 10 is a diagram for explaining a conventional example.

[Explanation of symbols]

1 controller (touch information generation means, control means) 2 Decoder (touch information generation means) 3 switch matrix (touch information generator) 4 Key-in register (touch information generation means) 5 memory (temporary storage means) 6 memory registers 7,8 Set / reset circuit (control means) 9 increment counter 10 inverter 11 Velocity Register 12 note register 13 flag register (control means) S1 and S2 switches (first and second key switches)

Claims (3)

(57) [Claims] 1. A first key switch and a second key switch, which are provided for each key and are sequentially turned on / off in response to a key release operation, and a key press depending on an on / off state of the first and second key switches. Alternatively, a touch information generation unit that detects a key release, generates state information indicating a key press event or a key release event, and generates touch information corresponding to on / off timings of the first and second key switches, Temporary storage means for temporarily storing state information and the touch information, and when the touch information stored in the temporary storage means is in a state of waiting for reading from the outside, the touch information generation means causes a new key press or key release. Is detected,
A touch detection device, comprising: a control unit that invalidates the state information and the touch information corresponding to the previously pressed key or the previously released key related to the selected key . 2. The state information is formed from at least information for identifying either key depression or key release and information for identifying completion or incompleteness of key depression or key release. 1. The touch detection device according to 1. 3. The touch detection device according to claim 1, wherein the temporary storage means stores the state information and the touch information in a storage area corresponding to each key.