JPS5912492A - Touch response apparatus for electronic musical instrument - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a touch response device for an electronic musical instrument, and more particularly to an electronic musical instrument touch response device for detecting a touch state when a key of an electronic musical instrument is pressed.

In electronic musical instruments, unlike pianos, it is very difficult to subtly convey the touch state of the keys to the sounding body because of the use of switch means, and various devices have been devised near the keys.

In order to obtain such a touch-sensitive keyboard, in general electronic musical instruments, the volume of the musical sound generated is determined by detecting the pressing speed of the pressed key as the key is pressed.

It has a touch response function that controls the tone.

In addition to the key-on signal, the electronic musical instrument having the touch response function generates a key-pressing speed detection signal instead of indicating the key-pressing speed for controlling tone and volume.

Various configurations have been proposed to obtain such a key pressing speed detection signal, one of which is to count the number of stitches in the time from the start of key depression to the end of key depression using a counter circuit. There is a known device that outputs the number of stitches as a key pressing speed detection signal.

Although this configuration is easy to integrate into an integrated circuit, it has the disadvantage that a counter circuit for the number of stitches must be provided for each key, making the configuration extremely complicated.

Furthermore, first and second switches are provided on the duplicate key, and these first and second switches are turned on by pressing the key in sequence, and the detection time difference at this time is determined and used as the key pressing speed. Response mechanisms are also known.

According to this touch response detection speed, for all the keys on the keyboard, for example, 61 keys, there is a time error in scanning the time difference between the first and second switches, so the accuracy must be increased. In order to improve the performance, there were problems such as the need to shorten the keyboard scanning time.

Another touch response detection device generates an analog voltage in response to key presses, applies the analog voltage to an analog-to-digital conversion circuit, and outputs touch response data using the digital output of the analog-to-digital conversion circuit as an address. Japanese Patent Laid-Open No. 55-22750 discloses a device in which the read data is read out and added to a digital-to-analog conversion circuit to obtain an analog signal, and then the musical tone is controlled by the analog signal. It is.

However, the touch response device with this configuration has the disadvantage that it requires multiple circuits such as a memory circuit in order to read the touch data using the digital value after analog-to-digital conversion of the analog voltage corresponding to the touch of the key as an address. there were.

The present invention has been made in view of the above-mentioned drawbacks, and when an analog voltage corresponding to a key touch response generated by a key pressing operation is converted into digital by an analog-to-digital conversion circuit, one non-linear analog-to-digital conversion circuit is used. By using a conversion circuit, it is possible to arbitrarily obtain touch control data with the required focus, and the main selling point is to maintain the output according to the touch response of the keyboard and eliminate the lag in keyboard operation time. According to the invention, in order to achieve the above object, there is provided a charging circuit formed by connecting a series circuit of a first switch and a capacitor to a power source, and a resistor connected in parallel to the capacitor via a second switch. a key touch detection and holding circuit, which is connected to the output of the key touch detection and holding circuit, and is operated by a signal from the key assigner. The gate circuit outputs of a plurality of circuits that are a set of gate circuits are made common, and the output terminals of the plurality of gate circuits are added to one analog-to-digital conversion circuit to obtain key touch information. This is achieved by the characteristic touch response device of the electronic musical instrument.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system diagram of the electronic musical instrument touch response device of the present invention, in which 1 is a key manual unit consisting of a plurality of keys of the electronic musical instrument and a sui-nochi etc. arranged near the keys; The scanning result output of the human power unit 1 is applied to the key assigner 2 and also to the touch control data generation unit 9. The key assigner 2 detects the pressing operation state of the keyboard in the key manual section 1, and its output is input to the scale register 3, envelope counter, and status section 4. The scale register 3 is a register in which the code of the musical tone being sounded is stored. The output of the scale register 3 is input to a scale read only memory 5 (hereinafter referred to as ROM), and the address of the scale ROM 5 is accessed. The scale R
The OM 5 stores clock information corresponding to the key, and the data of the scale ROM whose address is accessed is output to the scale clock generator 6. The scale clock generator 6
Then, a scale clock to be generated is generated based on the data in the scale ROM 5, that is, clock information corresponding to the keyboard, and the scale clock is output to the waveform address counter 7. The waveform address counter 7 counts the clocks generated by the scale clock generator. This count increments each time a clock is input. That is, the count value increases at a specific speed. The output of the waveform address carantuff is the waveform memory 8 that accesses the address of the waveform memory 8.
Stores data for one wavelength of the musical tone to be generated, and its output is digital data corresponding to the musical tone.

On the other hand, an analog voltage E' corresponding to the pressing speed of the key input section 1 is added to the touch control data generating section described above, and the touch control data generating section 9 generates a 3-bit signal from the analog voltage proportional to the pressing speed of the keyboard. Digital data a, b, and c are generated.The digital data a, b, and c from the touch control data generating section 9 are input to the touch control clock generating section 10 and the envelope counter and status section 4.

The touch control clock generating section 10 receives a clock signal Eo obtained from an envelope clock generating section 11.
and the above 3-bit data a, b.

An envelope counter and status section 4 generates a clock E corresponding to the speed of pressing C and a status section 4. Envelope data is generated by counting the aforementioned clock E. The output of the envelope counter and status section 4 is output to a multiplication section 12, and also outputs statuses such as attack, decay, release, etc. to an envelope clock Q generation section 11.

The multiplier 12 multiplies the outputs of the envelope counter and status section 4 and the waveform memory 8 to convert the output into a digital-to-analog converter D/A (not shown in FIG. 1).
is output to. The digital data obtained from the multiplier 12 is a musical tone corresponding to the key, and the amplitude value thereof has a value corresponding to the speed at which the key is pressed. Therefore, this digital signal is converted into an analog signal using a digital-to-analog converter, which naturally corresponds to the pressed key. This is a scale that corresponds to the key, and a value that corresponds to the touch response.

FIG. 2 is a circuit diagram showing the relationship between the touch control data generating section 9 and the key power section 1 shown in FIG. If the keyboard has, for example, 61 keys, the detection and holding circuit corresponds to the number of keys.

The key touch detection holding circuit forms a charging circuit with a DC power source and a capacitor Co connected in series via a first normally closed switch SI, and a second normally closed switch connected in parallel with the capacitor Co. A discharge circuit is formed by S2 and resistor Ro.

S3 is a third normally open switch that is closed when a key is pressed, and the key assigner 2 outputs that, for example, the first key in the key input unit 1 has been pressed.

For example, when the first key is pressed, the first normally closed contact is opened and the electric charge stored in the capacitor Co through the first switch S1 is transferred to the second normally closed switch S2. through resistor R.

discharge to. Next, the second sealing switch S2 is opened,
Discharge stops. In this way, a charge corresponding to the pressing speed of the first key is held in the capacitor Co.

Next, when the third matrix switch S3 is closed, the key assigner 2 determines which key is turned on, so it applies a signal corresponding to the key, for example, the signal SCI in this case, to the gate of the field effect transistor GA+. As a result, the field effect transistor GA+ (hereinafter referred to as gate circuit) connected to the output terminal of the key touch detection and holding circuit 1-1 is turned on, and the charge accumulated in the capacitor Co is passed through the amplifier (AMP). A voltage corresponding to the voltage is input to the next stage analog-to-digital conversion circuit (A/D). Gate circuit GA2. ....

GAa+ is wired in the same manner as the first circuit above in correspondence with the key touch detection and holding circuit, and gate circuits GAI, GA2 .
..., the outputs of GAs+ are connected in common to the AMP
In the above embodiment, there is only one A/D for each of the 61 keys.

The plurality of gate circuits GA + , GA 2 ,
. . , GAa+ and one AMP and A/D, as shown by the dashed line in FIG. 2, the touch control data generating section 9. , is configured. A/D indicated by the chain line is A
Consisting of a resistor network that divides the input voltage from MP, A
Six sets of resistors R11, R12, R21, R22° R31, R32 are connected in series between the MP output line and ground.
8R41゜R42・R51,R52・R61,R6
2 are connected in parallel with each other and the first set of resistors R++.

A divided voltage is applied to the first comparator COM+ from the connection midpoint of R12. Similarly, resistors R2 from the second set to the sixth set
1, R22・R31, R32・R41, R42° R
51, R52° R61° R62 connection middle points from 2nd to
AM given to the sixth comparator COM 2 to COM a
The data line voltage of P is connected to the seventh comparator COM 7
Add to. In other words, A/D conversion is performed based on whether or not the voltage divided by the resistor network exceeds the reference voltage of the comparators COM+ to COM7. There is a relationship between

When R+ l+R12=R21+R22 Child R6+-←R62=R, comparators COM I~COM? −
The input voltage of is (Rl 2/
R)V・(R22/R)V・・・(R62/R)
V-V becomes R+ 2<R22<R32<R42<R52<R
If you select 62, for example, 0 when the AMP output voltage ■ is a certain value.
,0,1,1,1. Outputs such as l and l are obtained. The values are converted by a binary encoding circuit PLA to obtain digital data a, b, and c.

Now, the first and second sui, 7chi St, shown in Fig. 2,
In Figure 3, which shows the relationship between the time difference of 32 and the discharge waveform of the capacitor holding voltage ■, the horizontal axis shows the two contact time differences of the first and second switches, O, t+, ..., up to t7, and the capacitor Co The vertical axis represents the holding voltage of 0. Vl, V
a, .
Normal linear A/D because it is almost not 1 to 5.
Now, in order to make the relationship between the time difference between the two key contacts, that is, the key pressing speed and the output volume, as shown in FIG.
It has a complicated configuration such as 22750, which performs A/D conversion, outputs the converted value in addition to the ROM, and performs further D/A conversion.

Therefore, in the present invention, by appropriately selecting the ratio of the resistance values of the above-described resistor network and performing proportional A/D conversion, the D/A output data is not separately converted into volume control data. Perform both conversions at the same time. For this purpose, the relationship shown in Figure 3 is expressed as V + = (R/Rl 2 )
Set R11 to R62 as follows: V7V2=(R/R22)Vl Va=(R/R62)Vl. Furthermore, if the charging/discharging resistor Ro and capacitor Co in Fig. 2 are selected so that the reference voltage of the comparator and v7 are equal, then for each condition of the two contact time difference t (pressing speed of 11!) and the capacitor holding voltage V. The resistor network (buffer output) output has a fifth
Digital data as shown in the figure is retrieved. For example, when the time difference between two contacts is Q<t≦1+, the AMP output ■ is ■l≦■
<Vll (see Figure 3), from the upper digit MSB to the lower digit LSB of the resistor network 1.1, 1, 1, 1゜1.1
digital data can be obtained.

The digital data as shown in FIG. 5 of these comparators COM+~COM7 is a positive output and inverter IN+~
IN? The negated output through the matrix is given to the binary encoding circuit PLA configured as a matrix, and the key-on signal given to the gate group GATE related to the three row lines intersecting the column line of the matrix is used to input the comparators COM+ to COM t. When the output is 1.1,1°1.1,1.1, the output is 3 bits 0, 0.0, and when the output is 0°o, o, o, o, o, o, it is 3 bits 1°1. .1 and other correspondences as shown in Fig. 5, step-like touch response data a, b, which is close to the ideal curve, where the broken line shows the correspondence between the two contact time difference and the volume in Fig. 4.
, obtain c. According to this configuration, it is possible to reliably change the volume stepwise even in portions where there is a small speed difference.

The touch response data a, b, and c mentioned above are converted as shown in Figure 6, and if the maximum envelope value is taken, it becomes 111.
is 63. in decimal. 110=127.101=191
...0OO=5], 1.

As explained in detail above, according to the present invention, since the analog voltage corresponding to the touch of the key is non-linearly A/D converted, the obtained data is directly converted into touch response data without using any other conversion means. A/D with the smallest bit possible
Only one conversion circuit is required for multiple keys. Accurate touch response is obtained even when pressing keys at high speeds,
No error occurs even when the key is pressed at a slow speed.

Furthermore, since the touch signal is converted for each key, put on standby, and taken into an LSI or the like together with the signal indicating that the key is turned on, channel selection can be performed using only the key-on signal, and conventional circuits can be used as they are.

[Brief explanation of drawings]

Fig. 1 is a system diagram of the touch response device of the electronic musical instrument of the present invention, Fig. 2 is a circuit diagram of the key manual section and touch control data generation section of Fig. 1, and Fig. 3 is the key touch detection shown in Fig. 2. A curve diagram showing the relationship between the output voltage of the holding circuit and the time difference between two contacts, FIG. 4 is a step curve diagram showing the relationship between the time difference between two contacts and the volume, and FIG. 5 is used to explain FIGS. 3 and 4. Buffer data and touch response data values, 6th
The figure shows digital data values showing the relationship between touch response data and envelope maximum value. 1...Key personnel department, 2...Key assigner, 3...
・Scale register, 4... Envelope counter and status section, 5... Scale ROM, 6...
- Scale clock generation section, 7... Waveform address counter, 8... Waveform memory, 9... Touch control data generation section, 10... Touch control clock generation section, 11... Envelope clock generation section,
1-1 to l-61...Key touch detection holding circuit, G
A+~GAa+...Gate circuit. Patent applicant Casio Computer Co., Ltd. agent patent attorney
Yoshiyuki Osuga 56 Fig. 3 Orlx'J+t516 t"uke, Ikamai Fig. 5

Claims (2)

[Claims] (1) A charging circuit consisting of a series circuit of a first switch and a capacitor connected to a power source, and a discharging circuit consisting of a resistor connected in parallel to the capacitor via a second switch. , a key touch detection and holding circuit composed of a third switch/notch that gives the key on state to the key assigner, and a gate circuit connected to the output of the key touch/notch detection and holding circuit and operated by a signal from the key assigner. A set of gate circuit outputs of a plurality of circuits are made common, and the output ends of the plurality of gate circuits are connected to one analog-digital conversion circuit G
In addition, there is provided an electronic musical instrument response device which obtains key touch information. (2) A non-linear analog-to-digital converter circuit that divides the output of the gate circuit, adds the output of the resistor network to a comparator, and adds the output of the comparator to a converter circuit that converts into a binary signal. 2. The touch response device for an electronic musical instrument according to claim 1, wherein the touch response device is configured to obtain information.