JPH025056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a touch switch device used as an external input means for electronic wristwatches, electronic compact computers, and the like.

Recently, small electronic calculators and calculator watches that incorporate calculators into electronic wristwatches have been commercialized, and touch switches are used as a means of inputting numerical values and calculation instructions for these small electronic calculators and calculator watches. It is being considered.

As this type of touch switch, there are known a voltage-dividing resistance type touch switch that utilizes a resistance component of the human body, and a capacitive detection type touch switch that utilizes a capacitance component of the human body.

As shown in FIG. 1, a voltage-divider resistor type touch switch has a pair of touch electrodes 2A and 2B disposed on an insulating substrate 1 such as a watch glass, and one electrode 2A is connected to a high potential V _SS (for example, 0V) side, and connect the other electrode 2B to the CMOS inverter 3.
It is connected to the input side of , and also connected to the low voltage V _DD (for example, -1.5V) side via a resistor R.

Therefore, when the touch electrodes 2A and 2B are not touched, the potential V _A on the input side of the inverter 3 is
It is pulled towards the low potential V _DD side via the resistor R,
The output voltage V _put of the inverter 3 becomes a high potential level. Furthermore, by touching the pair of touch electrodes 2A and 2B with fingers as shown in the figure, a contact resistance Z due to the human body is formed between these electrodes, as shown by the broken line in the figure. Therefore, inverter 3
The input voltage V _A becomes a divided voltage due to the contact resistance Z and the tensile resistance R. If the resistance value of the resistor R is determined so that this voltage is equal to or higher than the threshold voltage of the inverter 3, the input voltage V _A of the inverter 3 will be at a high potential level, and the output signal of this inverter 3 will be at a low potential level V It will be _SS level. Therefore,
The switch is ON when the output voltage V _put of the inverter 3 is at a low potential level, that is, when the touch electrodes 2A and 2B are touched, and the output voltage V _put of the inverter 3 is at a high potential level, V _DD level, that is, when the touch electrodes 2A and 2B are not touched. When the switch is turned off, it can function as a switch.

In this type of touch switch,
The contact resistance Z is the surface condition of the touch electrodes 2A and 2B,
In addition, large variations occur depending on the condition of the human body in contact, the external atmosphere, etc. For this reason, the resistance R
The resistance value of must be set in advance to a large value in accordance with the fluctuation of the contact resistance Z. However, while increasing the resistance value of the tensile resistance R improves the sensitivity of the switch and makes it easier to turn on the switch, there is a drawback that noise components to the inverter 3 increase, making malfunctions more likely.

Furthermore, if a large number of touch electrodes are arranged on an object where the surface space is extremely limited, the area of the touch electrodes themselves and the distance between the touch electrodes will become extremely small, making it difficult for the fingertip to touch the desired touch electrode. In this case, there is a very high possibility that other touch electrodes adjacent to the desired touch electrode will also be touched at the same time.

In such a case, the touch switch shown in FIG. 1 has the drawback that all the touch switches corresponding to the touched touch electrode are turned on at the same time, resulting in malfunction of switch input. Further, as a capacitive detection type touch switch, for example, the touch switch shown in FIGS. 6 and 7 of Japanese Patent Application Laid-Open No. 52-78076 or Japanese Utility Model Application No. 53-63564 is known.

That is, in the former case, when there is no touch input, a pulse signal of a predetermined period is input to the latch circuit for touch detection, and when there is a touch input, the pulse signal is generated by the time constant consisting of the capacitor component and resistance of the human body. The touch input is detected by distorting the signal and making it below the threshold voltage so that it is not picked up by the latch circuit.Also, in the latter case, the pulse signal is similarly distorted, but the pulse signal is is distorted to such an extent that there is a time delay before reaching the threshold, and when there is a time delay, it is determined that there is a touch input.

However, even in such a capacitance detection type touch switch device, if a plurality of touch switches are touched at the same time, all the touched touch switches are turned on.

This invention was made in view of the above circumstances, and its purpose is to turn on only the desired touch switch even if the human body touches multiple touch electrodes at the same time. Therefore, it is an object of the present invention to provide a touch switch device that can prevent malfunctions in switch input.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 6. Note that this embodiment is an example in which the touch switch according to the present invention is applied to a calculator watch. First, the basic principle of the present invention is shown in FIGS. 2 and 3. In FIG. 2, reference numeral 11 is a watch case that is worn on the wrist through a back cover (not shown), and a transparent touch electrode Tx is attached to the upper surface of a front glass 12 formed on the front surface of the watch case. ing. The watch case 11 is connected to the high potential V _DD (logic value "1") side of the power supply voltage, and is also used as one touch electrode. Therefore, when the wristwatch is worn on the wrist, the touch switch can be turned on by touching the touch electrode Tx with the human body. Further, the symbol Cx is a stray capacitance component indicating a value corresponding to the stray capacitance value, and in this embodiment, for example, this is detected as a pulse delay amount as described later. This is due to the electrode wiring capacitance caused by the wiring of the touch electrode Tx and the OMOSIC used in this example.
This is due to gate capacitance caused by the high input impedance of the gate. Also, the sign Cy
When touching the touch electrode Tx, the watch case 11
This indicates a value corresponding to the contact capacitance value of the human body that occurs between the touch electrode Tx and the touch electrode Tx, and this is also detected, for example, in the present embodiment by the amount of delay of the pulse as described later. Therefore, the stray capacitance component
Cx always exists, but the contact capacitance component Cy is artificially created.

Further, symbol A is a rectangular wave signal with a predetermined period (for example, 64 Hz), and this rectangular wave signal A is input to each gate of a CMOS inverter 16 consisting of a resistor 13N channel MOS transistor 14 and a P channel MOS transistor 15. The switching operation of transistors 14 and 15 is controlled. Note that the N-channel MOS transistor will hereinafter be simply referred to as an N transistor, and the P-channel MOS transistor will be simply referred to as a P transistor. The source side of the N transistor 14 is connected to a low potential V _SS of the power supply voltage.
(logical value "0"), and a high potential _VDD is supplied to the source side of the P transistor 15 via the watch case 1. The output signal of the CMOS inverter 16 is connected to the touch electrode Tx and is also supplied to the OMOS inverter 17.

The output signal of the CMOS inverter 17 determines whether a human body is in contact with the touch electrode Tx, that is,
It is taken out as a determined signal B, which is used to determine the presence or absence of a touch.

Therefore, when the rectangular wave signal A shown in FIG. 31 becomes a high potential level and is input to the CMOS inverter 16 in a state where the human body is not touching the touch electrode Tx, the output signal of the CMOS inverter 16 becomes a low potential level. level, and the output signal of the inverter 17 becomes a high potential level. At this time, CMOS
Since the output signal of the inverter 16 is affected by the stray capacitance component Cx, the rise of the output signal of the inverter 17 is delayed by the time To with respect to the rectangular wave signal A, as shown in FIG. 3.

Next, if the human body touches the touch electrode Tx,
A contact capacitance component Cy is formed between the touch electrode Tx and the watch case 11, and this contact capacitance component Cy is connected in parallel to the stray capacitance component Cx, so the output signal B of the inverter 17 is It is output with a delay from the rectangular wave signal A by a time corresponding to the combined capacitance of the contact capacitance component Cx and the stray capacitance component Cy. By the way, the magnitude of the contact capacitance component Cy varies depending on the contact area between the human body and the touch electrode Tx or the contact state such as the pressing force, but is approximately proportional to the contact area. This is because the fingertip and touch electrode are similar to the capacitor's counter electrode, just as a capacitor with a large-area counter electrode has a larger capacity than a capacitor with a small counter electrode. This is thought to be because it works. Therefore, when the contact capacitance component Cy is small, the output signal B of the inverter 17 is
Output signal when no human body is touching Tx [3rd
2], as shown in FIG. 3,
The rising edge is output with a further delay of time _T1 . Further, when the stray capacitance Cy is large, the output signal B of the inverter 17 is output with a rising time delayed by a time (T ₁ +T ₂ ), as shown in FIG. 3 and 4.

In this way, the delay time of the output signal B of the inverter 17 increases according to the magnitude of the contact capacitance component Cy. Therefore, if the human body touches not only the desired touch electrode but also other touch electrodes adjacent to it, the difference in the contact area between the human body and the touch electrode may cause the contact between the desired touch electrode and the touch electrode. The contact capacitance components corresponding to other touch electrodes should be larger for the former than for the latter. Therefore, by comparing the magnitude of each contact capacitance component corresponding to multiple touch electrodes, the touch electrode with the largest value is detected, and only the switch of this touch electrode is activated.
By turning it ON, you can effectively prevent switch input malfunctions.

For these reasons, the specific configuration of the touch switch device according to this embodiment is as shown in FIGS. 4 and 5. In addition, Figures 4 and 5
In the figure, the same components as those shown in FIG. 2 are given the same reference numerals, and detailed explanation thereof will be omitted.
Thus, in the touch switch device of this embodiment, when the watch is worn on the wrist, as in the case described above, a desired one of the many touch electrodes T ₁ to _{T o} arranged on the surface of the watch can be selected. When a human body touches the touch electrode, the switch corresponding to the touch electrode is turned on. In the figure, reference numeral 21 denotes a pulse generation circuit, and this pulse generation circuit 21 generates a switch designation code W consisting of a binary code of predetermined bits in order to sequentially designate n touch electrodes T ₁ to _To in a time-division manner. The signal is output and input to a sense circuit 22 whose details will be described later.
Note that the code W is a code obtained by counting the rectangular wave signal A described above. Therefore, the sense circuit 22 receives the rectangular wave signal A output from the pulse generating circuit 21 and the clock pulse (for example,
2048Hz) is also input.

Here, the configuration of the sense circuit 22 will be explained with reference to FIG. In the figure, reference numeral 31 denotes a decoder that decodes the switch designation code W, and this decoder 31 sequentially outputs timing signals a ₁ to _ao whose phases are shifted from each other in accordance with the switch designation code W. The timing signals a ₁ -a _o are input as gate control signals to the corresponding AND gates AN ₁ -AN _o . Also, each AND gate AN ₁ ~ _{AN o}
A rectangular wave signal A is also input. For this reason,
A square wave signal A is output from each AND gate AN ₁ to _{AN o.}
Output can be obtained sequentially in synchronization with The output signals of these AND gates AN ₁ to AN _o are input as gate control signals to the corresponding transmission gates G ₁ to G _o , and the output signals of each of the AND gates G ₁ to _{G o} are
Controls ON/OFF operation. Each of these transmission gates G ₁ to _{G o} are connected P/N
It is constructed by combining a transistor and an inverter, and is turned ON when the input outputs of the AND gates AN ₁ to AN _o are at a high potential level, and turned OFF when the output is at a low potential level. The touch electrodes T ₁ -T _o input via each transmission gate G ₁ -G _o are collectively connected to the output side of the CMOS inverter 16 . That is, each transmission gate G ₁ -G _o connects a corresponding touch electrode T ₁ -T _o .
It is connected to the output side of the CMOS inverter 16 in a time-division manner.

In addition, the signals sequentially output from each AND gate AN ₁ to AN _o in synchronization with the rectangular wave signal A are as follows:
Together with the output signal of the CMOS inverter 16, these signals are respectively applied to the output signal control circuit 32. This control circuit 32 receives signals O ₁ -O o corresponding to the touch electrodes T ₁ -T _{o .}
and each output signal O ₁
〜O _o is, for example, when a human body touches touch electrode T ₃ among the touch electrodes T ₁ to _{T o} , when the switch designation code W specifies touch electrode T ₃ , at the rising edge of the square wave signal A. When the logic value becomes "1" in synchronization and the touch electrode _T3 is no longer in contact, the touch designation code W synchronizes with the falling edge of the rectangular wave signal A when the touch electrode _T3 is designated. The logical value becomes "1". Only when any of the touch electrodes _T1 to _T0 is touched, the memory counter 2, which will be described later, is activated.
This is for releasing the reset state of the 7 and m bit counters 38 and detecting the touched electrode, and the outputs of the above-mentioned signals O ₁ to O _o are sent to the OR gate 23 in FIG. In addition, sense circuit 2
2, an operation signal for a push-button type clear key used in operating the computer is inputted via a terminal S. The switch input signal S by this clear key is applied to the NAND gate 33 to which the output signal B of the inverter 17 is input. The output signal of this NAND gate 33 is transmitted to an AND gate 34 to which the square wave signal A and the clock pulse are input.
given to. The clock pulses output from this AND gate 34 are input to a counter 35 and counted. Note that the counter 35 is reset in synchronization with the rise of the rectangular wave signal A. The contents of this counter 35 are RAM
(random access memory) 36 and is written therein. This RAM3
6 has n memory areas corresponding to each of the touch electrodes T ₁ to _{T 0} , and each of these memory areas is addressed in accordance with the switch designation code W from the pulse generating circuit 21 . Further, a switch input signal S is inputted to the RAM 36 as a read/write command signal, and when the switch input signal S is at a high potential level, it receives a write instruction, and when it is at a low potential level, it receives a read instruction.

Also, the counter 3 is counted up sequentially by the clock pulse from the AND gate 34.
5 content n and content m read from RAM 36
is sent to a comparison circuit 37 and compared in magnitude. This comparison circuit 37 compares the contents of the counter 35 with each other each time the contents of the counter 35 are counted up.
It is configured to detect whether or not the relationship n>m with the content read from the RAM 36 is established, and to output the determination signal C immediately after detecting the relationship n>m.

That is, this sense circuit 22 has a delay time T ₀ due to the stray capacitance Cx of each touch electrode T ₁ to _T 0 (this T ₀ differs for each touch electrode) as shown in FIG.
A determination signal C indicating that a delay time _T0 has elapsed since the rise of the rectangular wave signal A, and a determination signal B which rises with a further delay corresponding to the contact capacitance due to a touch on the touch electrode. By outputting these, the contact capacitance of the human body (T ₁ in FIG. 3, T ₁ +T ₂ in FIG. 3) is detected and compared by a circuit described later. That is,
When the clear key is operated, the switch input signal S becomes a logical value "1". For this reason, RAM36
is specified for writing. Then, at the timing when the switch designation code W designates the touch electrode _T1 , the AND gate _AN1 is deregulated by the decode output _a1 from the decoder 31, so the transmission gate _G1 is turned ON.
The touch electrode _T1 and the CMOS inverter 16 are connected in series. Therefore, the delay amount of the signal to be determined B output from the inverter 17 is the stray capacitance component Cx between the touch electrode _T1 and the watch case 11.
It will be due to. In addition, when the switch input signal S becomes the logical value "1", the NAND gate 33
The output signal remains at the logical value "1" until the signal B to be determined rises. And the square wave signal A
When the counter 35 rises, the counter 35 is reset in synchronization with this and starts counting the clock pulses from the AND gate 34. After that, when the signal to be determined B rises with a delay corresponding to the stray capacitance after the rectangular wave signal A rises, the NAND gate 33
Since the output signal becomes the logical value "0", the counting operation of the counter 35 is stopped, and the contents of the counter 35 at this time are written to the RAM 36. on the other hand,
In the RAM 36, the storage area corresponding to the switch designation code W that designates the touch electrode T ₁ is addressed, so that the stray capacitance between the touch electrode T ₁ and the watch case 11 counted by the counter 35 is equal to the clock pulse. This number is written into a designated storage area of the RAM 36. Similarly, at the timing when the switch designation code W designates each of the touch electrodes _T2 to _T0 , each storage area of the RAM 36 has a delay time _T0 of the clock pulse for the stray capacitance between each touch electrode and the watch case 11. Each is memorized by a number.

Next, referring back to FIG. 4, another circuit configuration will be explained. Signal O ₁ output from sense circuit 22
~O _o are input to the OR gate 23, respectively. Therefore, the output signal E of the OR gate 23 has a logical value of "0" when the human body is not touching any of the touch electrodes _T1 to _T0 , and has a logical value of "0" when the human body is touching at least one of them. It becomes “1”. Further, the judgment signal C from the sense circuit 22 is sent to the counter 25 via the inverter 24.
is input as a reset signal. This counter 25 is reset when the judgment signal C is at a low potential level, that is, when the output signal of the inverter 24 is at a high potential level, and when the judgment signal C becomes a high potential level, the clock pulse from the pulse generating circuit 21 is reset. Start counting. Further, the signal to be determined B from the sense circuit 22 is inputted as a write clock to the data to be compared storage counter 26, and the contents of the counter 25 at the time of the rise of the signal to be determined B are written into this storage counter 26. Contents Z of this memory counter 26
is another storage counter 2 that stores compared data.
7 and a comparison circuit 28 which compares the magnitude of the data to be compared. The storage counter 27 stores the largest comparison data at the present time among the comparison data sequentially sent from the storage counter 26.
The content Z' of this memory counter 27 is stored in the comparator circuit 28.
sent to. The comparison circuit 28 includes each memory counter 2
The contents Z and Z' of 6 and 27 are compared in size, and when it is determined that there is a relationship of Z≧Z', a signal G with a logical value of "1" is output to the AND gate 40. There is.

Further, the output signal E of the OR gate 23, that is, the signal that becomes a logic value "1" when one of the touch electrodes is touched and returns to "0" when the switch designation code W specifies that touch electrode after the touch is stopped is m (=n+1) via the inverter 29 and the memory counter 27 and the inverter 30
Each of the signals is input to the bit shift register 38 as a reset signal. m-bit shift register 3
8 sequentially shifts a signal with a logical value of "1" by one bit each time a timing pulse T is applied, which is outputted from the pulse generation circuit 21 at a constant period and every time the rectangular wave signal A falls, and ,
Switch designation code W is all touch electrodes T ₁ ~
The next m-bit output after specifying T _o is sent to the OR gate 23 via the inverter 39, the timing pulse T from the pulse generation circuit 21, and the comparison circuit 28.
The signals G from the input terminals are applied to AND gates 40, respectively. The output signal H of the AND gate 40 is input to the storage counter 17 as a write command signal, and upon input of this signal H, the storage counter 27 stores the content Z sent from the storage counter 26. The output signal H of the AND gate 40 is also input as a write command signal to a latch circuit 41 to which the switch designation signal W is input from the pulse generation circuit 21. The latch circuit 41 stores the switch designation code W sent from the pulse generation circuit 21 when the output signal H of the AND gate 40 is input. The contents of the latch circuit 41 are then sent to a decoder 42 to which the m-bit output of the m-bit shift register 38 is input as an operation command signal. This decoder 42 converts the output from the latch circuit 41 into n parallel outputs, and these output signals are taken out as switch input signals SI ₁ to _{SI o} . Note that the switch input signals SI ₁ to SI _o are
The signal is sent to a switch input operating circuit (not shown), and the switch is operated so that when the switch input signal has a logical value of "1", the switch is turned on, and when the switch input signal has a logical value of "0", the switch is turned off.

Next, the operation of the embodiment will be explained with reference to the timing chart shown in FIG. Delay amount T ₀ of signal B to be determined relative to rectangular wave signal A due to the influence of stray capacitance component Cx of each touch electrode T ₁ to T _o
are stored as the number of clock pulses in each storage area of the RAM 36 by operating the clear key as described above.

Here, for example, a case where a human finger or the like comes into contact with the touch electrodes T ₂ and T ₃ will be explained. First, the decoder 31 outputs a timing signal a ₁ out of phase.
Since the signals ˜a _o are sequentially output, the transmission gates G ₁ ˜G _o are sequentially turned on. Therefore, each touch electrode T ₁ -T _o is connected to the CMOS inverter 16 in a time division manner.

That is, when the timing signal _a1 shown in FIG. 6 is output from the decoder 31, the transmission gate _G1 is turned on, so that the touch electrode _T1 and
A CMOS inverter 16 is connected, and a signal is output from the inverter 17 with a delay of T ₀ depending on the stray capacitance between the electrode T ₁ and the watch case 11 . Thus, a clock pulse is output from the AND gate 34 from the rising edge of the rectangular wave signal A, and this clock pulse is output from the counter 3.
5, and the value is sent to the comparison circuit 37. In addition, the RAM 36 is addressed by the switch designation code W that specifies each touch electrode T ₁ , and reads out and compares the number of clock pulses already written as the stray capacitance between the touch electrode T ₁ and the watch case 11 from the storage area. It is sent to circuit 37. Therefore, the comparison circuit 37
When the content of 0 reaches the value obtained by counting the next clock pulse to the number of clock pulses already stored in the RAM 36, n>m is detected and a comparison signal C is output as shown in FIG. 6. Therefore, although the counter 25 in FIG. 4 counts clock pulses only when the determination signal C is at a high potential level, the determined signal B, which is given as a writing clock to the storage counter 26, is the sixth clock pulse. Figures 7 and 8
As can be seen, nothing is written to the storage counter 26 because it has already been output.

When the timing signal _a1 is output from the decoder 31 as shown in FIG.
Since the human body is touching T ₂ , the touch electrode T ₂
The delay amount of signal B to be determined is the stray capacitance component.
Since it is a composite capacitance of _Cx and the contact capacitance component Cy, as shown in FIG.
Furthermore, it starts up with a delay of the contact capacitance delay time T ₁ . Therefore, counting starts from the rise of the determination signal C. The contents of the counter 25 are written into the storage counter 26 at the rising edge of the signal B to be determined.
The contents written in this memory counter 26 are as follows:
This is the magnitude of the contact capacitance component Cy, and is sent to the storage counter 27 and comparison circuit 28. At this time, in the comparison circuit 28, the storage counter 2
The comparison data Z sent from 6 and the comparison data Z' sent from the storage counter 27 were compared in size, but in this case, the comparison data Z' is "0", and this Therefore, the comparison circuit 18
In this case, the relationship Z≧Z' holds true, and a signal G with a logical value of "1" is output. When this signal G is output, the AND gate 40 outputs the signal shown in FIG.
Since h ₁ is output, the contents of the memory counter 26 are written into the memory counter 27 . Furthermore, since the output H of the AND gate 40 is sent to the latch circuit 41, the latch 41 stores the contents of the code W at this time.

Next, at the output timing of the timing signal _a3 shown in FIG. 6, the touch electrode _T3 and the CMOS inverter 16 are connected. Therefore, if the contact with the touch electrode T ₃ is made over a wider area than the contact with the touch electrode T ₂ , the contact capacitance is larger than that with the touch electrode T ₂ .
As shown in FIG. 6 and 7, the rise of the signal to be determined B is further delayed by a time _T2 . Therefore, the number of clock pulses counted by the counter 35 also increases, and the content written to the memory counter 26 at the rising edge of the signal B to be determined is
The content of the memory counter 27 written at time T ₂ is greater than the content of the memory counter 27 by the amount of time T ₂ , therefore, the comparator circuit 2
8 outputs signal G. By outputting this signal G, the AND gate ₄₀ outputs h2 in FIG.

In this way, by comparing the contact capacitance of each touch electrode T ₁ to _{T o} in each timing signal a ₁ to _{a o} , at the end of the timing signal a _o , the code when the contact capacitance is the largest is found. W is latch circuit 4
1 will be stored. Therefore, at the next timing of the timing signal _ao , that is, when the last m bits of the m-bit counter 38 become 1,
By decoding the contents of the latch circuit 41 by the decoder 42, a signal is obtained from any one of SI ₁ to _{SI o} . The above SI ₁ to SI _o correspond to the touch electrodes T ₁ to _{T o} , respectively, and therefore, the switch signal of the touch electrode with the largest contact capacitance can be obtained.

In the above embodiment, the watch case is used as one of the touch electrodes, but the present invention is not limited thereto. It may be configured as follows.

Further, in the above embodiment, the magnitude of the contact capacitance component is compared by counting the clock pulses inputted during the period from the rise of the judgment signal C to the rise of the signal to be judged B, and based on this counted value. Although the present invention is configured to perform a size comparison, the present invention is not limited to this, and may be configured to perform arithmetic processing using an arithmetic circuit.

Furthermore, the present invention is of course applicable not only to calculator watches but also to small electronic computers and the like.

As explained in detail above, the present invention detects the contact capacitance component corresponding to each touch electrode, compares the magnitude of each contact capacitance component, and then selects the touch switch of the touch electrode corresponding to the largest contact capacitance component. Since the touch switch is configured so that only the touch switch is turned on, even if the human body accidentally touches other touch electrodes in addition to the desired touch electrode, only the touch switch corresponding to the desired touch electrode will be turned on. This makes it possible to reliably prevent switch input malfunctions.

[Brief explanation of drawings]

FIG. 1 shows a conventional touch switch, FIGS. 2 to 6 show an embodiment of the present invention, and FIG.
3 is a diagram showing the basic principle of the present invention, FIG. 3 is a timing chart thereof, FIG. 4 is a circuit diagram of the touch switch device according to this embodiment, and FIG. 5 is a diagram of the sense circuit 22 applied to the same embodiment. Detailed configuration diagrams and FIGS. 6 1-9 show timing charts. T ₁ ~ T _o ...Touch electrode, Cy...Touch capacitance component, 1
1...Pulse generation circuit, 12...Sense circuit, 15...
Counter, 16, 17... Memory counter, 18...
Comparison circuit, 21...n-bit shift register, 24
...Latch circuit, 25...Decoder.

Claims (1)

[Scope of Claims] 1. a plurality of touch electrodes T ₁ to _{T o} ; rectangular wave pulse signal supply means 21, 31, and 16 for supplying a rectangular wave pulse signal of a predetermined period to each of the plurality of touch electrodes; and the plurality of touch electrodes. When the touch electrode is not touched, a first delay signal delayed by a predetermined amount with respect to the rectangular wave pulse signal of the predetermined period is outputted, and when it is touched, the first delay signal is further delayed with respect to the first delay signal. a delayed signal output means 17 for outputting second delayed signals that are different depending on the touch area; and for each of the plurality of touch electrodes, the second delayed signal relative to the first delayed signal according to the touch area; detection means 35, 36, 37, 25, 26 for detecting the delay amount as count value data by counting high frequency clock pulse signals; and count value data for each touch electrode detected by the detection means. Comparison means 2
7, 28, and switch signal output means 40, 41, 42 for outputting a switch signal corresponding to the touch electrode with the largest delay amount based on the comparison result by the comparison means.
A touch switch device comprising: and.