JPH01167895A - Touch detecting circuit - Google Patents

Abstract

PURPOSE:To detect an initial touch and an after-touch by a single detecting means by holding a pressure detection output after a prescribed time has elapsed after having exceeded a reference value, outputting it as an initial touch signal, and also, outputting the pressure detecting output as an after-touch signal. CONSTITUTION:Pressing force of a finger which is applied through an operating button, etc., is detected by a pressure sensor SR1, etc., and supplied to a key ON detecting circuit 6R1. Subsequently, a detection output for passing through an A/D converter 7 is compared with a reference value by a computing circuit 8, a comparison output when it has exceeded the reference value and a comparison output for passing through a delaying circuit 9 are processed by an AND circuit 10 and a key ON signal KON is outputted. In such a way, the holding pressure detection output is outputted as an initial touch signal through a register 11 controlled by the circuit 9 after a prescribed time has a elapsed after having exceeded the reference value, and an output of the converter 7 is outputted as an after-touch signal. Accordingly to this constitution, an initial touch and an after-touch can be detected by using a single detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a touch detection circuit used in an electronic musical instrument, which detects an initial touch and an aftertouch of a performance keyboard or an operation button.

``Conventional technology'' For example, in an organ, the opening/closing valve only operates in conjunction with the key, so once the key is pressed, no matter how hard you press the key, there will be no change in the sound. However, on a piano, the strength of the sound changes depending on how hard you press the keyboard, or what is called a touch. On the other hand, electronic keyboard instruments are known that detect the initial touch or aftertouch of a keyboard and change the sound accordingly.

Here, the initial touch corresponds to the rate of change in the pressing force at the moment of the keystroke, and the aftertouch refers to the continuous change in the pressing force while the key is being pressed after the keystroke. This corresponds to

In conventional electronic keyboard instruments, the method of detecting an initial touch is to use a break contact (normally closed contact) that turns on when the keyboard is not pressed, and a break contact that turns on when the keyboard is pressed in. ”, and when the keyboard is pressed, the break contact turns “off”.
A method has been used to obtain an initial touch signal corresponding to the rate of change in pressing force at the moment of keystroke by counting the time interval from when the key is turned on until the make contact is turned on. In addition, the method used to detect aftertouch was to install a pressure sensor that detects the pressing force applied to the keyboard, and to obtain an aftertouch signal corresponding to continuous changes in the pressing force from this pressure sensor. .

``Problems to be Solved by the Invention'' By the way, in conventional electronic keyboard instruments, in order to detect the initial touch, a break contact, a meter contact, and a counting circuit for measuring time are required for each key. In addition, a separate pressure sensor had to be provided to detect aftertouch. In this way, since the initial touch and the aftertouch are detected by separate detection means, the configuration becomes complicated, and furthermore, since the structure has contacts, there is a problem that chattering occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a touch detection circuit that can detect initial touch and aftertouch using a single non-contact detection means.

"Means for Solving the Problem" This invention provides a pressure detection means that outputs a signal corresponding to a pressing force applied via a performance keyboard or an operation button, and an output of the pressure detection means that is equal to or higher than a reference value. timing generating means for outputting a timing signal when a predetermined time has elapsed since , and capturing and holding the output of the pressure detecting means each time the timing signal is supplied;
A holding means for outputting the held content is provided, and the output of the holding means is outputted as a signal corresponding to an initial touch, and the output of the pressure detection means is outputted as a signal corresponding to an aftertouch. .

"Operation"' According to the above configuration, the initial touch and aftertouch of the performance keyboard or operation button can be detected simultaneously by a single pressure detection means. It is no longer necessary to separately provide a contact point and a pressure sensor for aftertouch detection, simplifying the configuration, and furthermore, since the structure does not have a contact point, chattering does not occur.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a grip IR used in the embodiment.
, FIG. 3 is a front view showing an example of use of the same embodiment.

First, the configuration of the grips I R and I L will be explained with reference to FIG. 2. Grip IR is for the right hand, grip II is for the left hand, and since these are configured to be symmetrical to each other, hereinafter, grip l for the right hand will be used.
Only R will be explained, and the reference numeral R of each part will be read as L, thereby replacing the explanation of the left-handed grip IL.

In the right-hand grip 1R, 2R is a case shaped so that it can be held with the right hand, and this case 2R has a base between the thumb and index finger to fit the right hand when gripped. A curved surface 2Ra that comes into close contact with the ring is formed, and a locking part 2Rb that is held between the ring finger and the middle finger is formed so that it does not come off from the gripped hand (see Fig. 3). In addition, seven pressure sensors Snl to Snl are installed in case 2R.
R7 is included. Each of these pressure sensors SR1
~SR1 is each composed of a push button provided in the case 2R so as to be freely protrusive and retractable, and a piezoelectric element whose specific resistance value changes depending on the pressing force applied via the push button.

Here, the arrangement of the pressure sensors SR, to SR7 will be explained. The pressure sensors SR, ~SR, are arranged at positions where they can be easily pressed with the five fingertips of Grisob IR when gripped with the right hand, and the pressure sensors SR, ~SR,
, SR, are arranged side by side in the horizontal direction at positions that can be suppressed with the thumb, pressure sensors SR1, Srt, are arranged side by side in the vertical direction at positions that can be suppressed with the index finger, and pressure sensors SRs, SRe, S R7 are arranged side by side in the vertical direction at positions that can be suppressed with the index finger. They are arranged vertically in positions that can be suppressed by the middle finger, ring finger, and little finger. With this arrangement, the seven pressure sensors SR, to SR7 can be easily operated with five fingers of one hand.

And each pressure sensor SR, ~SR? When pushed in with a fingertip, a pressing force acts on the piezoelectric element inside, causing its resistance value to change.

Each of these pressure sensors SR, ~SR, is connected to the cable 3R.
As shown in FIG. 3, it is connected to a belt-shaped main body 5 worn on the waist of the performer via a connector 4R.

The external structure of this belt-shaped main body 5 is shown in FIG.

Next, in FIG. 1, one end of each piezoelectric element SR, to SR7 is commonly connected, led to the main body 5 via a cable 3R, and then grounded. On the other hand, each pressure sensor SR1~
The other end of S R7 is led to main body 5 via cable 3R, pulled up by pull-up resistors r, and connected to key-on/touch detection circuits 6R and 6R7, respectively.

The key-on/touch detection circuits 6R, ~6R, are connected to each pressure sensor S Rl-S R? This circuit outputs a key-on signal KON, initial touch data ITD, and aftertouch data AFD based on the detection voltages supplied from the respective controllers. Here, the key-on signal KON is output when the pressing force on each pressure sensor SR3 to SR7 reaches a predetermined strength or more, and the initial touch data ITD is This is data obtained in response to the initial touch, that is, the rate of change in the pressing force at the moment of pressing.Furthermore, aftertouch data AFD is data obtained from each pressure sensor SR1 to SR.
This data corresponds to continuous changes in the pressing force until the end of pressing .

The key-on/touch detection circuits 6R, to 6R7 include an A/D converter 7, a comparison circuit 8, a delay circuit 9, and an AND gate 1.
0, and register ll. A/
The D converter 7 converts the detection voltages supplied from each pressure sensor SR, to SR7 into digital detection voltage data VD of predetermined bits, and converts the obtained detection voltage data VD into aftertouch data. AFD
Output as ! Comparison circuit 8 compares detected voltage data VD output from A/D converter 7 and reference voltage data V.
ref, and when V D > V ref, the output is set to the "■]" level. The output of the comparator circuit 8 is supplied to one input terminal of the AND gate IO, and after being delayed by a predetermined time T via the delay circuit 9, is supplied to the other input terminal of the AND gate IO. Therefore, when a predetermined time T has elapsed since V D > V ref, the output of the AND gate IO becomes “I
]" level, and this "H" level output is output as the key-on signal KON.

Further, the output of the delay circuit 9 is supplied to the load terminal of a register 11, and this register 11 is connected to the delay circuit 9.
When the output rises to "■-level", the detection voltage data VD output from the A/D converter 7 is latched, and this launched data is used as the initial touch data I.
Output as TD.

Here, with reference to FIG. 5, the reason why the data latched by the register 11 becomes the initial touch data r'I'D when a predetermined time T has elapsed after V D > V ref becomes explain.

FIG. 5 shows pressure sensors SR, ~SR? 2 is a graph showing the relationship between the suppressing force applied to the piezoelectric element and its resistance value. In this figure, when the pressing force reaches Po,
It is assumed that the resistance value is Rref and the above-mentioned detection voltage VD is equal to the reference voltage Vref. Then, when the pressing force is applied with a relatively weak touch, that is, when the rate of change of the pressing force is slow, when the predetermined time T has elapsed, the pressing force becomes Pl and the resistance value becomes n 1 nit+. On the other hand, when the pressing force is applied with a relatively strong touch, that is, when the changing speed of the pressing force is fast, 1 s
At the point when IT has elapsed, the pressing force is p 1 (>
PI), and the resistance value is R1nitt (< R1ni
t+). In this way, the resistance value of the piezoelectric element at the time when a predetermined time T has elapsed after the pressing force exceeds Po is determined according to the degree of strength of the touch; if the touch is strong, the resistance value is R1niLt, and if the touch is weak, the resistance value is R1niLt. In this case, the resistance value is R1n1L. The detected voltage data VD output from the A/D converter 7 is applied to each pressure sensor SR.
,~corresponds to the resistance value of the piezoelectric element in SR7, so
By latching this detected voltage data VD with the register 11, initial touch data ITD is obtained.

Key-on/touch detection circuits 6R5 to 61 configured as described above
1? is each pressure sensor S n of the right hand grip IR
l ”” S R? Each is provided correspondingly,
Key-on/touch detection circuit 6 with exactly the same configuration as these
L, ~6L, is the left hand grip 11. Each pressure sensor SL, ~S L ? Each is provided correspondingly.

These key-on/touch detection circuits 6R, ~6R7,
Key-on signal KON output from 6L and 6L7 respectively
, initial touch data! TD1 and aftertouch data ATD are supplied to multiplexer 12.

The multiplexer 12 performs a key-on/key-on operation based on a channel select signal C8 supplied to its select terminal.
Touch detection circuit 6R, ~6rt7, 6L1~6L? One set of data consisting of the key-on signal KO1N, initial touch data ITD, and aftertouch data ATD output from each of the input terminals is selected and output. Also, 14 is a CPU (central processing unit), 16 is a ROM (read only memory) in which programs used by the CPU 14 are stored, and 17 is an RA used as a work area.
M (random access memory). CPU 4
The key-on signal obtained by sequentially changing the channel select signal C8 supplied to the multiplexer I2 and scanning the output data of the key-on/touch detection circuits 6R, ~6R7, 6L, and ~6L at high speed KON
, initial touch data ITD1 and aftertouch data ATD are sequentially transferred to the RAM 17, and based on the transferred data, key code data KC for specifying the pitch and volume data VOL for specifying the volume are generated.
and timbre specification data TD for specifying the timbre. In addition, the above key-on signal KON, key code data KC, volume data VOL, and tone specification data TD
are collectively referred to as musical tone control data MCD.

Reference numeral 18 denotes an operating section, which is comprised of a bushing switch (see FIG. 4) and a code that encodes the output of the manipulated bushing switch and outputs it to the CPU 14. 19 is an LCD (liquid crystal) display (see Figure 4), 20
is musical tone control data MCD supplied from CPU t4.
21 transmits musical tone control data MCD supplied from the CPU 14 to a midi (MID I; Musica).
l Instrument DigitalInte
This is a midi circuit that converts the data into data of the rface) standard and outputs it to the outside via the output terminal 21a.

Next, the operation of the above-mentioned embodiment will be explained.

First, when performing a performance, the performer wears the belt-shaped main body 5 on the waist as shown in FIG.
Connect the connectors 4R, 4L at the tips of the cables 3R, 3L extending from and the musical tone generator are connected by a connecting cable. Then, the main body 5 worn on the waist and the musical tone generator are turned on. Next,
Operate the button switch on the operation unit 18 to specify N-line/wireless (data transmission method to the musical tone generator), and also select each pressure sensor SR, ~SR of the grips tR, it,
,,SL, ~SL? Assign functions to.

Here, as shown in FIG.
Based on the outputs of pressure sensors SR3 to SR4 in the first
Octave to 4th octave specified, pressure sensor S
Based on the combination of outputs from Rs to SR7 (“1” indicates key-on, “0” indicates key-off), the scale is c.
n, Dn, ......, I3n, C"' are specified, and the pressure sensor SL in the grip IL for the left hand
The function of each pressure sensor shall be assigned so that the strength of key-on and touch is specified based on the outputs of pressure sensors SLs to SL, and the tone is specified based on the outputs of pressure sensors SLs to SL7. do.

Next, the performer holds grip IR with his right hand and grip I with his right hand.
Hold L with the left hand, operate the button switch that instructs the start on the operation section 18, and start playing. From then on, the CPU
14 is a key-on/touch detection circuit 6R, to 6R7, 6
t,, ~6 Key-on signal KON obtained from L7,
The initial touch data ITD and the aftertouch data ATD are sequentially transferred to the RAM 58, musical tone control data MCD is created based on the transferred data, and the created musical tone control data MCD is output to the midi circuit 21. The midi circuit 21 receives musical tone control data MCD.
is converted into MIDI standard data and supplied to the output terminal 21a, and the data output from the output terminal 21a is supplied to an external musical tone generator via a connection cable. As a result, a musical tone based on the supplied MIDI standard data is formed in the musical tone generating device, and is emitted as a musical tone from the speaker.

In this case, each pressure sensor S IN of the grips IR and IL
t~Sl'? ,,SL,~SL? As shown in Figure 6, each function is assigned to , so for example,
Press the pressure sensor SR1 with your right thumb to specify "1st octave", press the pressure sensor SR with your right middle finger to specify the scale "Gn", press the pressure sensor SL with your left hand to specify "flute", Furthermore, in this state, when the pressure sensor SLl is pressed with the thumb of the left hand, a musical tone of scale G' is emitted from the musical tone generator with a touch corresponding to the degree of pressing (strength or weakness) and with the tone of a flute. ,
When pressure sensor SL3 is pressed with the index finger of the left hand, a tone that is a semitone higher than the scale G1 is emitted with a touch corresponding to the degree of pressing, and when pressure sensor SL is pressed with the index finger of the left hand, a tone that is a semitone higher than the scale G1 is emitted with a touch that corresponds to the degree of pressing. A musical tone that is a semitone lower than G1 is emitted.

In this case, when the pressure sensors SR1 to SR for specifying an octave or the pressure sensors SL5 to SL7 for specifying a timbre are pressed, the CPU 14 determines that the specification is valid for the period that these are pressed. do. Note that once the pressure sensors SR, ~SR, and SL5~Sr, 7 are pressed, this designation may be maintained, and as shown in FIG. Based on the outputs of the sensors SL, ~SL 7, various functions may be assigned so that various effects such as volume level, vibrato strength, presence or absence of wah-wah, etc. can be specified. By operating the switch,
The performer can set it arbitrarily.

Here, if "wireless" is selected as the transmission method to the musical tone generator, musical tone control data MCD is supplied to the transmitter 20. Further, the LCD display 19 displays the operation details of the operation unit 18 and the like.

According to one embodiment described above, a single pressure sensor Srt;
Based on the output signal of ~5R7 (SL,, ~SL,),
Both initial touch and aftertouch can be detected.

In addition, in the above-mentioned embodiment, the grips IR, I
The explanation was given using an example where the application is applied to a special electronic musical instrument in which a musical tone generator is controlled by the pressure level of each fingertip of the hand holding the L, or the combination of fingers pressed, but it can also be applied to a normal electronic keyboard instrument and the keyboard Initial touch and aftertouch may be detected. In addition, each pressure sensor S R
+ ~5n7 (SL, ~5Lff) output signal is A/D
Of course, the converter 7 may be configured to process the analog signal as it is without converting it into a digital signal.

"Effects of the Invention" As explained above, according to the present invention, there is provided a pressure detection means that outputs a signal corresponding to a pressing force applied via a performance keyboard or an operation button, and an output of the pressure detection means. timing generating means for outputting a timing signal when a predetermined time has elapsed since the pressure has exceeded a reference value; and each time the timing signal is supplied, the output of the pressure detecting means is taken in and held, and the held content is stored. The output of the holding means is outputted as a signal corresponding to the initial touch, and the output of the pressure detecting means is outputted as a signal corresponding to the aftertouch. Initial touch and aftertouch of the keyboard or operation buttons can be detected simultaneously by the pressure detection means of the condolence, and unlike conventional methods, a contact point for initial touch detection and a pressure sensor for aftertouch detection are provided separately. It is no longer necessary,
Since the configuration is simplified and the structure does not have any contacts, chattering does not occur.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, Fig. 2 is a perspective view showing the external configuration of the grip IR and IL of the embodiment, and Fig. 3 shows an example of use of the embodiment. FIG. 4 is a front view, FIG. 4 is a perspective view showing the external structure of the belt-shaped main body of the same example, FIG. 5 is a graph showing the characteristics of the piezoelectric element used in the same example, and FIG. Pressure sensor SR, ~S IN7. SL, -9L? FIG. 7 is a diagram showing a modified example of function allocation. tR, tt,...Grip, SR1~SR? , SL, ~SL? ......Pressure sensor (pressure detection means), 6R, ~6
R7,6Ll~6R. ...Key-on/touch detection circuit, 7...
- A/D converter, 8...Comparison circuit, 9...Delay circuit (8 and 9 are timing generation means), 11...Register (holding means).

Claims (1)

[Scope of Claims] Pressure detection means for outputting a signal corresponding to a pressing force applied via a performance keyboard or an operation button, and a predetermined time period elapsed after the output of the pressure detection means exceeded a reference value. a timing generating means for outputting a timing signal at the time when the timing signal is supplied, and a holding means for capturing and holding the output of the pressure detecting means and outputting the held content every time the timing signal is supplied, the holding means A touch detection circuit characterized in that the output of the pressure detection means is outputted as a signal corresponding to an initial touch, and the output of the pressure detection means is outputted as a signal corresponding to an aftertouch.