KR101056627B1 - Method and apparatus for detecting the location of touch in capacitive touchscreen- equipped devices - Google Patents

Abstract

PURPOSE: A touch screen location detection apparatus and method thereof are provided to maximize detection speed of channels by processing all channels of a touch screen. CONSTITUTION: A charging unit(210) charges a capacitor in a channel of a capacitive touch screen according to a charge control signal. A measuring unit(220) generates a detection signal for monitoring a multi-channel and combines a discharging current of the capacitor. A position detecting and controlling unit(230) generates a Walsh code corresponding to the number of the touch screen. The position detecting and controlling unit detects the touch location of the touch screen.

Description

Touch location detection device and method thereof in capacitive touch screens {Method and Apparatus for Detecting the Location of Touch in Capacitive Touchscreen- Equipped Devices}

The present invention relates to touch position detection in a capacitive touch screen, and more particularly, to capacitive touch screen for maximizing detection speed and minimizing various noise and inter-channel interference by processing all channels of the touch screen simultaneously. The present invention relates to a touch position detecting device and a method thereof.

Currently, the mobile device and other mobile device markets are rapidly expanding. Accordingly, high performance of high-definition, high resolution, 3D graphics, and other mobile displays are progressing, and input means are also being developed as a touch screen method of directly touching a screen using a conventional keypad. As you can see from recent success stories, such as Apple's iPhone and Nintendo's Nintendo DS, mobile devices using touchscreens are intuitive and easy to use, so they can be used without a manual.

As the adoption of touch screens spreads, interest in a touch interface as a new mobile user interface (UI) is increasing. Here, the UI may be referred to as a means for assisting the interaction between the user and the information device and the user and the content / application, and may be formed in various forms such as visual, tactile, sound, and feeling. In conventional mobile phones, the input means have been designed and used separately from the display, and the interaction between them has been handled separately in the application. On the other hand, the touch interface has a feature of processing input and display together on the same screen. For example, an iPhone user can use two fingers to zoom in and out while viewing a picture on the screen, and immediately see the result on the screen. That is, the biggest advantage of the touch interface is that the input and the display are closely related to each other and thus the usability can be greatly increased.

Looking at the conventional touch screen to which the touch interface is applied as follows.

1) resistive touch sensing

As shown in FIG. 2, the touch and the coordinates are sensed by "contacting" the upper and lower indium tin oxide (ITO) plates, and are classified into four-wire and five-wire resistive film methods.

The 4-wire resistive film method uses both upper and lower plates for coordinate sensing. The 5-wire resistive film method uses an upper plate as an electrode and only a lower plate for coordinate sensing. Although the 5-wire resistive film method is more durable than the 4-wire resistive film method, on the other hand, since ITO is used as an electrode as a whole, the resistance between the electrodes is formed as high as 40 to 50 Ω, and thus, current consumption is large.

The disadvantage of this resistive film method is that it is weak in durability and impossible to implement a multi-touch function. In other words, it is difficult to cope with the trend of requiring multi-touch because two or more points cannot be read at the same time.

2) Capacitive Touch Sensing

As shown in FIG. 3, two ITO plates are disposed with an insulating layer (double adhesive) interposed therebetween to form a capacitive touch screen having an inherent capacitance value.

Here, the capacitance means that two (conductive) electrodes are arranged at regular intervals, and when a voltage is applied to one electrode, a difference in the amount of charge accumulated in each electrode occurs, and an electric field is formed between the electrodes.

The capacitance C is the capacity at which these two electrodes can accumulate charge. In other words, the larger the capacitance, the more charge can be stored. The capacitance is determined by the size of the electrode (Area), the gap between the electrodes (Gap), the material (Dielectric) existing between the gaps, and is expressed by the following formula.

As described above, when a voltage is applied to one electrode (ITO plate) of the touch screen, charge is accumulated in proportion to the capacitance between the electrodes. The touch controller IC detects the touch position by converting the capacitance value into an electrical signal and reading it.

As shown in FIG. 4, since the finger is also a conductor, capacitance is increased when a voltage is applied while the finger is touched on the touch screen. Therefore, by measuring the capacitance value, it is possible to determine whether the touch by detecting the change in the measured capacitance value. When touched, fluctuations in capacitance values, typically several pF levels, occur. Therefore, the smaller the capacitance value inherent in the touch screen, the larger the amount of change in capacitance value.

In the capacitive touch screen structure, as shown in FIG. 5, two ITO films are coated on the LCD panel to form a capacitive touch screen. At this time, each film is composed of M vertical lines and N horizontal lines, the embodiment of detecting the X and Y coordinates under this structure is as follows.

X coordinate detection: Apply voltage on the horizontal line and read the capacitance on the vertical line.

Y coordinate detection: Apply voltage on the vertical line and read the capacitance on the horizontal line.

Conventional touch screen technology employing such capacitive touch sensing is a method of detecting whether a touch is performed by measuring a change amount of charge / discharge time or frequency.

Therefore, such a conventional capacitive touch screen inevitably causes a time delay, and thus has a disadvantage that the sensing speed is very slow compared to the resistive film method.

On the other hand, according to the trend of the mobile device as described above, the rapid development of the touch screen technology is progressing, the development direction is summarized into the following two.

First, the share of capacitive touch technology capable of multi-touch is expanding. Here, the multi-touch refers to a technology for providing information by recognizing a contact object (for example, a finger) that touches various points of the touch screen. The case and patent of the Apple iPhone shown in FIG. 1 is a good example of a UI utilizing multi-touch. This method senses the touch position by sequentially sensing each channel, so the sensing speed is very slow, and handwriting / gesture recognition is impossible.

Second, the importance of ultra-fast, multi-channel detection technology for smart gesture UI and handwriting recognition is increasing day by day.

In order to realize handwriting / gesture recognition in such a capacitive touch screen method, it is necessary to improve sensing speed, and for this, technologies related to multi-channel simultaneous sensing and high speed are required.

Accordingly, the present invention is proposed to cope with the multi-channel simultaneous sensing and sensing speed improvement request required in the touch screen as described above,

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and method for detecting a touch position in a capacitive touch screen which maximizes the detection speed by simultaneously processing all channels of the touch screen.

Another object of the present invention is to provide an apparatus and method for detecting a touch position in a capacitive touch screen capable of maximizing detection speed to enable handwriting / gesture recognition.

Another object of the present invention is to provide an apparatus and method for detecting a touch position in a capacitive touch screen for minimizing various power / electromagnetic noises and interchannel interference.

"Touch position detection device in a capacitive touch screen" according to the present invention for solving the above problems,

A charging unit configured to charge capacitors respectively provided in a plurality of channels of the capacitive touch screen according to a charging control signal;

A measuring unit which combines the discharge currents of the capacitors to generate detection signals simultaneously monitoring the multi-channels;

Generating a Walsh code corresponding to the number of channels of the touch screen as a charging control signal, and providing the Walsh code to the charging unit; Location detection and control.

Preferably "Touch position detection device in a capacitive touch screen" according to the present invention,

Generating a discharge control signal for discharging the capacitor from the position detection and control unit;

The electronic device may further include a discharge unit configured to discharge the capacitor according to the generated discharge control signal.

In addition, the Walsh code is characterized in that the orthogonal Walsh code.

In addition, the charging unit,

Characterized in that the charge control switch for supplying or cutting off the charging power in accordance with the charge control signal.

In addition, the measuring unit,

A discharge switch for discharging the charging current of the capacitor;

And an analog / digital converter configured to generate an analog detection signal that simultaneously monitors multiple channels by combining discharge currents discharged through the discharge switch, and converts the generated analog detection signal into a digital detection signal corresponding thereto. .

In addition, the position detection and control unit,

A charge control signal generation module generating a Walsh code for charge control and touch position determination and providing the generated Walsh code as a charge control signal and a touch determination reference signal;

A multiplication module multiplying the detection signal output from the measurement unit with the touch determination reference signal and outputting the result signal as a touch detection signal;

And a control module for analyzing a touch sensing signal output from the multiplication module to determine a touch position, and outputting a measurement control signal and a discharge control signal.

According to the present invention for solving the above problems the "touch position detection method in a capacitive touch screen",

Generating a Walsh code for charging control and determining a touch position, and providing a generated Walsh code as a charging control signal to the charging unit to control charging of a capacitor included in each channel of the capacitive touch screen;

A measurement step of controlling the measurement unit to generate a detection signal for simultaneously monitoring the multi-channels by combining the discharge currents of the capacitors;

A touch signal extraction step of calculating the detection signal and a reference signal for touch determination and extracting a result signal as a touch detection signal;

And a touch position recognition step of simultaneously analyzing the extracted touch sensing signals to recognize a plurality of touch positions of a multi-channel.

The reference signal is characterized in that the charge control signal.

And a discharging step of controlling a discharging unit to discharge a capacitor provided in each channel of the touch screen after recognizing the touch position.

According to the present invention, by sensing all the channels at the same time has the advantage that high-speed detection of the touch position in the capacitive touch screen, and also has the advantage that can significantly improve the detection performance by minimizing the effects of noise and interference .

In addition, all channels can be detected at high speed at the same time, so that handwriting / gesture recognition can be performed.

1 is an explanatory diagram for explaining touch screen technology trends and a multi-touch concept;
2 is an explanatory diagram for explaining the structure of a conventional resistive touch screen.
3 is an explanatory diagram for explaining a capacitance in a conventional capacitive touch screen.
4 is an explanatory diagram for explaining a conventional capacitive touch sensing principle.
5 is a structure diagram of a conventional capacitive touch panel.
6 is an overall configuration diagram of a touch position detection device in a capacitive touch screen according to the present invention.
7 is a schematic diagram of a charging schedule generation method according to the present invention;
8 is a schematic diagram of an embodiment of a measuring unit according to the present invention;
9 is a schematic diagram of an embodiment of a position detection and control unit according to the present invention;
FIG. 10 is an explanatory diagram of the position detection and control unit of FIG. 9; FIG.
11 is a flowchart illustrating a touch position detection method in a capacitive touch screen according to the present invention.

Hereinafter, described in detail with reference to the accompanying drawings a preferred embodiment of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

6 is an overall configuration diagram showing a preferred embodiment of the "touch position detection device in a capacitive touch screen" according to the present invention, the capacitive touch screen 100, the charging unit 210, the measuring unit 220, Position detection and control unit 230, and the discharge unit 240.

The touch screen 100 is provided with any number of channels (horizontal channels and vertical channels), and each channel is provided with a plurality of capacitors C1 to C8 for capacitance detection.

개의 채널로 구성된다. 여기서

≥ (M+N)이다.The touch screen 100 may be composed of M vertical channels and N horizontal channels. Therefore, the touch screen 100 has a total of (M + N) channels. box). In this case, the touch sensing device

It consists of two channels. here

≥ (M + N).

The charging unit 210 performs a function of charging the capacitors C1 to C8 respectively provided in the plurality of channels of the capacitive touch screen 100 according to the charging control signal. As shown in FIG. 6, the charging is performed. It is preferable to include a charge control switch (S1 ~ S8) for supplying or cutting off the charging power in accordance with the control signal.

The measurement unit 220 performs a function of generating a detection signal that simultaneously monitors multiple channels by combining discharge currents of the plurality of capacitors C1 to C8. As illustrated in FIG. 6, the capacitor C1 is performed. C10) generates an analog detection signal simultaneously monitoring the multi-channel by combining a discharge switch S10 for discharging the charging current and a discharge current discharged through the discharge switch S10, and generating the generated analog detection. It includes an analog / digital conversion unit 221 for converting the signal into a digital detection signal corresponding to the output.

The position detection and control unit 230 generates a Walsh code corresponding to the number of channels of the touch screen 100 as a charging control signal and provides the charging control signal to the charging unit 210 and generated by the measuring unit 220. The detection signal is operated with the generated Walsh code to detect a contact position of the touch screen 100.

As shown in FIG. 9, the position detection and control unit 230 generates a Walsh code for charge control and touch position determination, and provides the generated Walsh code as a charge control signal and a touch determination reference signal. A multiplication module 232 for multiplying the signal generation module 231, the detection signal output from the measurement unit 220 and the touch determination reference signal, and outputting the resultant signal as a touch detection signal; and the multiplication module 232. And a control module 233 for analyzing the touch detection signal output from the touch panel to determine a touch position and outputting a measurement control signal and a discharge control signal.

The position detection and control unit 230 also functions to generate a discharge control signal for discharging the capacitors C1 to C8.

The discharge unit 240 performs a function of completely discharging the capacitors C1 to C8 according to the generated discharge control signal, and includes a discharge switch 241 and a resistor 242.

In the capacitive touch screen according to the present invention configured as described above, the touch position detecting apparatus reads the capacitance value of each channel of the touch screen 100 at a T second period from the position detection and control unit 230 and converts the capacitance value into an electrical signal. , To detect the touch position.

개의 소 구간(小구간)으로 나뉜다.Here, the operation period T seconds is defined as a touch sensing interval, and the touch sensing interval is again

It is divided into small sections.

As shown in FIG. 7, the small section is divided into a charging section for charging a capacitor and a measurement section for measuring a discharge current of the capacitor.

The biggest feature of the present invention is to generate a Walsh code using a charging schedule using an orthogonal code sequence and to simultaneously process (charge and measure) all channels according to the schedule, thereby realizing high speed of touch sensing. It is.

개의 Orthogonal Code Sequence(각

bit 길이)를 생성하고, 이에 따라

개 터치 감지 소 구간에서 채널별로 충전 여부를 결정하는 것이다. 이 경우 Orthogonal Code Sequence의 속성상, 채널별 충전량(充電量)을 모두 더하더라도, 각 채널별 충전량으로 쉽게 분해할 수 있다. 따라서 본 발명은 상기 Orthogonal Code Sequence의 특징을 활용하여 터치 감지 고속화 및 잡음/간섭 최소화란 목적을 달성한다. Here, Walsh code generation for the charging schedule is

Orthogonal Code Sequences (each

bit length) and accordingly

It is to determine whether to charge for each channel in the small touch sensing period. In this case, due to the nature of the Orthogonal Code Sequence, even if the channel charge amount is added, it can be easily decomposed into the charge amount for each channel. Accordingly, the present invention achieves the purpose of speeding up touch sensing and minimizing noise / interference by utilizing the features of the orthogonal code sequence.

개의 Orthogonal Walsh Code Sequence를 생성하여 충전 제어신호로 충전부(210)에 전달한다. 도 7은 K=3인 경우의 Orthogonal Walsh Code Sequence를 적용한 예이며, 터치스크린(100)의 채널 개수에 따라 8, 16, 32, 64 Sequence로 임의로 확장하여 적용할 수 있다.To this end, the position detection and charging control signal generation module 231 of the controller 230 is

It generates two Orthogonal Walsh Code Sequence and delivers to the charging unit 210 as a charging control signal. 7 is an example of applying an Orthogonal Walsh Code Sequence in the case of K = 3, and can be arbitrarily extended to 8, 16, 32, and 64 sequences according to the number of channels of the touch screen 100.

(= 8) 개의 소 구간으로 나누며, 각 소 구간 내의 충전 구간에서의 동작, 즉 터치스크린 충전 여부를 Orthogonal Walsh Code Sequence에 따라 결정한다. 예컨대, 충전 구간에서 제어신호가 하이(High)일 경우에만 충전부(210)의 충전 제어스위치(S1 ~ S8)를 제어하여 터치스크린(100)의 각 채널에 구비된 커패시터에 충전 전원(vcc)을 공급하여 충전하고, 측정 구간에서는 상기 충전 제어신호를 로우(Low)로 유지하여 상기 커패시터의 충전을 방지하게 된다.As shown in FIG. 7, the charge control signal according to the embodiment includes a touch sensing period of T seconds.

It divides into (= 8) small sections and determines the operation of the charging section within each small section, that is, whether the touch screen is charged according to the Orthogonal Walsh Code Sequence. For example, only when the control signal is high in the charging section, the charging control switches S1 to S8 of the charging unit 210 are controlled to supply the charging power vcc to the capacitors provided in the channels of the touch screen 100. Supply and charge, the charge control signal is kept low in the measurement section to prevent the charging of the capacitor.

In the charging unit 210, the charging control switches S1 to S8 are controlled according to the charging control signal as described above, so that the charging unit 210 does not charge the capacitor or perform a charging operation.

개의 채널로 구성되며 터치스크린(100)의 채널과 1:1로 대응하게 연결된다. 또한, 채널 1부터 채널

까지 총

개의 충전 제어스위치(S1 ~ S8) 및 제어신호를 포함하여 구성된다.That is, the channel of the charging unit 210 is

It consists of two channels and is connected to the channel of the touch screen 100 in a 1: 1 correspondence. Also, from channel 1 to channel

Total up to

Charge control switch (S1 ~ S8) and the control signal is configured.

Looking at the operation of the charging unit 210 with reference to Figure 6, the charge control signal for each channel performs a function of connecting the charge control switch (S1 ~ S8) to the VCC or the measurement unit 220, charge control The switches S1 to S8 perform the following operation according to the state of the charge control signal.

When the charge control switch (S1 ~ S8) is in the VCC connection mode (for example, when the control signal is High), the corresponding channel of the touch screen 100 is connected to a power source to charge the touch screen 100 When the charge control switch (S1 ~ S8) is in the measurement unit 220 connection mode (for example, when the control signal is Low), the connection of the channel and the power of the touch screen 100 is cut off, The channel is connected to the discharge switch S10 of the measurement unit 220.

에 해당하는 전하량이 충전되나, 터치가 발생하면(손가락이 닿으면),

에 해당하는 전하량이 충전된다.Therefore, each channel of the capacitive touch screen 100 has a different charge amount depending on whether it is touched or not. In other words, if a touch doesn't occur on the channel (the finger doesn't touch it),

Charge is charged, but when touch occurs (finger touches),

The amount of charge corresponding to this is charged.

Meanwhile, the touch sensing signal is generated by the measuring unit 220 having one discharge switch S10, the measuring capacitor C9, and the analog / digital converting unit 221 when the touch screen is touched (measured). .

Here, the measurement control signal for the discharge switch (S10) is generated from the position detection and control module 233 of the controller 230, the discharge switch (S10) performs the following role according to the measurement control signal.

When the discharge switch S10 is opened, the connection with the charging unit 210 is maintained in a blocked state. When the discharge switch S10 is closed, all channels of the charging unit 210 and the measurement capacitor C9 are connected. . As a result, the charge of the entire channel of the touch screen is moved to the measurement capacitor C9.

The measurement control signal is a control signal for opening the switch in the charging section of the touch sensing small section and closing the switch in the measuring section. After the charge transfer is completed (generally, a very short time is required), the analog / digital converter 221 converts the charge amount of the measurement capacitor C9 into a digital value. Such control is also preferably performed by the position detection and control module 233 of the control unit 230.

)만을 생성하도록 한다. 이를 위해 측정부(220)는 도면에는 도시하지 않았지만 초기에 터치가 발생하지 않았을 때의 정전용량 값(

)을 측정하여 보관하는 것이 바람직하다.The analog / digital converter 221 converts the potential difference (proportional to the amount of charge accumulated in the capacitor) across the measurement capacitor C9 to a digital value according to the control signal. In addition, by subtracting the amount of charge by the touch screen from the conversion value, the capacitance value by touch (0 or

). To this end, the measurement unit 220 is not shown in the figure, but the capacitance value when no touch occurs initially (

), It is desirable to measure and store.

Thereafter, the finally converted digital value is transmitted to the position detection and control unit 230.

An embodiment of the present invention when K = 3 is illustrated in FIG. 8.

In the case where a touch occurs in the channel 2 and the channel 8, the signal input to the position detection and the control unit 230 in the ideal situation without noise / interference is the sum of the signals for each channel (i.e., the charge amount), and thus the waveform and The digital conversion value is shown in the right waveform of FIG.

In this case, the dotted line shows a line corresponding to the average of each signal.

In an actual environment, the position detection and the input waveform of the controller 230 may have a form in which distortion is added by noise / interference. That is, power and electromagnetic noise are generated by the surrounding environment, and thus, the amount of charge charges is varied according to time, and inter-channel interference occurs as the channels are simultaneously charged / measured.

Therefore, in order to accomplish this, the present invention additionally uses the charging unit 240 to remove such noise and interference between channels.

That is, the charging unit 240 closes the discharge switch 241 according to the discharge control signal after every cycle of charging and measuring, and at this time, the electric charges charged in the touch screen are discharged to the ground terminal through the resistor 242. Therefore, it eliminates the inter-channel interference that may occur when the charge amount changes over time or charge / measure the channels simultaneously.

Meanwhile, the position detection and control unit 230 may use the multiplication module 232, and decompose each channel signal from an input (multiplexed) signal or digital value using an attribute of an orthogonal code sequence.

That is, when the orthogonal Walsh code for each channel is W1, W2, ..., W8, the following expression is satisfied.

로 표현할 수 있다. 여기서 α와 β는 scale factor에 해당하는 상수이다. 상기 Orthogonal Walsh Code의 특징으로부터 다음이 성립한다.At this time, if a touch occurs in the channel 2 and 8, the signal input to the position detection and control unit 230 in an ideal situation

. Where α and β are constants corresponding to scale factors. The following holds true from the features of the Orthogonal Walsh Code.

.....

Therefore, by multiplying the Orthogonal Walsh Code for each channel by V , it is possible to detect the presence or absence of a signal of the corresponding channel (ie, touch).

That is, as shown in FIG. 10, the multiplication module 232 of the position detection and control unit 230 converts an orthogonal code sequence value (charge control signal) for each channel into the multipliers 232a to 232h for each input digital value. The multiplication method generates a touch detection signal capable of determining whether a touch has occurred in a corresponding channel.

In the case of K = 3, when the digital value as shown in FIG. 8 is input as the detection value, the digital value (detection value) input by the multiplier for each channel is multiplied by the code sequence (charge control signal) for each channel. As a result, 8 is calculated for channels 2 and 8, and 0 is calculated for the other channels.

The calculated result is input to the control module 233 as a touch sensing signal, and the control module 233 determines that the touch is not performed when the operation result of the corresponding channel is 0, and is not touched.

Therefore, it is determined that a touch has occurred in the channel 2 and the channel 8, and the result of the touch sensing result is transmitted to another connected control device (not shown in the drawing, which controls the touch screen), so that subsequent functions can be performed. .

11 is a flowchart illustrating a "touch position detection method in a capacitive touch screen" according to the present invention, and shows a method of detecting a touch position in the position detection and the controller 230.

As shown in the figure, the battery enters an initial charging mode, generates a Walsh code for charging control and touch position determination, and provides the generated Walsh code to the charging unit 210 as a charging control signal to provide a capacitive touch screen ( The charging step (S101 ~ S103) for controlling the charging of the capacitor provided in each channel of 100) is performed.

When the charging of the touch screen 100 is completed, the display device transitions to the measurement mode and performs the measurement step S105 of controlling the measurement unit 220 to generate a detection signal simultaneously monitoring the multi-channel by combining the discharge currents of the capacitors. do.

Next, the touch signal extraction step (S107) for calculating the detection signal and the reference signal (charge control signal) for the touch determination and extracts the resulting signal as a touch detection signal is performed. That is, the channel-specific signal is decomposed from the input signal (multiplexed) or the digital value by using the attribute of Orthogonal Code Sequence.

Thereafter, the extracted touch detection signal is analyzed to perform a touch position recognition step (S109) of simultaneously recognizing a plurality of touch positions of a multi-channel. That is, a channel having a touch sensing signal of 0 is recognized as a channel without touch, and a channel whose touch sensing signal is not 0 is recognized as a channel having touch.

According to the present invention as described above, it is possible to speed up the time to detect the touch position by scanning the multi-channel at the same time.

In addition, the present invention, after performing the discharge step (S111) for controlling the discharge unit 240 to discharge the capacitors provided in each channel of the touch screen 100 after the touch position recognition, the charge amount by time This eliminates inter-channel interference that can occur as a result of fluctuations in or by charging / measuring channels simultaneously.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

100... touch screen
210... Charging part
220 ... Measuring unit
230... Position detection and control
240... Discharge

Claims (10)

In the device for detecting the touch position in the capacitive touch screen,
A charging unit configured to charge capacitors respectively provided in channels of the capacitive touch screen according to a charging control signal;
A measuring unit which combines the discharge currents of the capacitors to generate detection signals simultaneously monitoring the multi-channels; And
Generating a Walsh code corresponding to the number of channels of the touch screen and providing it to the charging unit as a charging control signal, and calculating a detection signal generated by the measuring unit with the generated Walsh code to detect a touch position of the touch screen; Touch position detection device in a capacitive touch screen comprising a position detection and control unit.
The method of claim 1,
The position detection and control unit generates a discharge control signal for discharging the capacitor,
And a discharge unit for discharging the capacitor according to the generated discharge control signal.
The touch position detecting apparatus of claim 1, wherein the Walsh code is an orthogonal Walsh code.
The method of claim 1, wherein the charging unit,
And a charge control switch for supplying charging power or connecting the capacitor and the measurement unit according to the charge control signal.
The method of claim 1, wherein the measuring unit,
A discharge switch for discharging the charging current of the capacitor;
And an analog / digital converter configured to generate an analog detection signal that simultaneously monitors multiple channels by combining the discharge currents discharged through the discharge switch, and converts the generated analog detection signal into a digital detection signal corresponding thereto. Touch position detection device in the capacitive touch screen, characterized in that.
The method of claim 1, wherein the position detection and control unit,
A charge control signal generation module generating a Walsh code for charge control and touch position determination and providing the generated Walsh code as a charge control signal and a touch determination reference signal;
A multiplication module multiplying the detection signal output from the measurement unit with the touch determination reference signal and outputting the result signal as a touch detection signal;
And a control module for analyzing a touch detection signal output from the multiplication module to determine a touch position and outputting a measurement control signal and a discharge control signal.
The method of claim 2, wherein the discharge unit,
And a discharge switch for discharging the charged charge of the capacitor by connecting it to a resistor connected to ground according to the generated discharge control signal.
In the method for detecting the touch position in the touch position detection device in the capacitive touch screen including a charging unit, measuring unit, discharge unit and position detection and control,
Generating a Walsh code for charging control and determining a touch position, and providing the generated Walsh code as a charge control signal to the charging unit to control charging of a capacitor included in each channel of a capacitive touch screen;
A measuring step of controlling the measuring unit to generate a detection signal for simultaneously monitoring the multi-channels by combining the discharge currents of the capacitors;
A touch signal extraction step of calculating the detection signal and a reference signal for touch determination and extracting a result signal as a touch detection signal; And
And a touch position recognition step of analyzing the extracted touch detection signals to simultaneously recognize a plurality of touch positions of a multi-channel.
The method of claim 8, wherein the reference signal is the charge control signal.
The touch position detection method of claim 8, further comprising a discharge step of controlling the discharge unit to discharge a capacitor included in each channel of the touch screen after recognizing the touch position. Way.

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