Sensor, sensing method for the sensor, and filter for the sensor

Sensor, sensor sensing method, and filter for sensor

The present invention relates to a sensor, and more particularly to a sensor capable of recognizing touch or proximity, a sensing method of the sensor, and a filter of the sensor.

Sensors that can detect the touch or proximity of a touch object (such as a finger or a pen) and output the result of the touch or proximity are gradually being used in household electrical appliances, computing devices, and portable communication terminals.

Korean Patent Registration No. 666699 discloses a touch sensor that can recognize a touch through a touch object by using the delay time difference between the sensing signal obtained by the capacitance of the touch element and the reference signal. Korean Patent Publication No. 2008-50544 discloses a delay calculation unit that can calculate the delay time difference between a sensing signal and a reference signal.

The touch sensor can be configured to recognize when the delay time does not vary according to the reference signal and the delay time varies according to the touch, and the delay time difference between the two is greater than the reference time. When the delay time difference is less than the reference time, it is recognized as not being touched by the touch object. However, even when the touch sensor is in a touch state through the touch object, the delay time may also be caused by environmental changes such as interference noise, detection position, coverage thickness, and/or touch pad type Therefore, the delay time difference may also change. Therefore, when the conventional touch sensor tries to recognize the above-mentioned types of touches, since the touch sensitivity will change according to the above-mentioned conditions, it is necessary to perform the adjustment operation of adjusting the reference time under this condition. In particular, adjustment operations are unavoidable during the development of the object. Because the electrical state between the contact and the touch sensor varies from product to product, the adjustment operation includes repeatedly changing the hardware and modifying the software. Therefore, the object development time will be extended due to the adjustment time.

The present invention provides a sensor that can shorten the adjustment operations necessary for object development, and can maintain unique sensitivity regardless of the environment and the like when the user uses the product.

The invention provides a sensing method of a sensor.

The invention provides a filter for a sensor.

An aspect of the present invention provides a sensor including: a sensing data output unit for outputting a sensing data that varies according to the touch or proximity of an object; and a measuring device for comparing the sensing Data and a threshold value to identify touch or proximity, and change a first intensity value to indicate the sensing data in the state of not being touched or not, and change a first intensity value in the state of touch or proximity The second intensity value is used to indicate the sensing data, the first intensity value and the second intensity value are used to change the critical value, and an output signal is output to indicate touch or proximity.

The aforementioned sensing data output unit can measure an impedance that varies according to touch or proximity, and output a value corresponding to the measured impedance as sensing data. The sensing data output unit may include: a sensing signal output unit for outputting a reference signal and a sensing signal delayed with the reference signal according to touch or proximity; and a delay time calculation unit for detecting A delay time difference between the sensing signal and the reference signal is detected, and a delay data corresponding to the delay time difference is output as the sensing data.

The sensing signal output unit of the aforementioned sensing data output unit may include: a reference clock generator for generating a reference clock signal; a reference signal generator for receiving the reference clock signal and outputting the reference signal ; And a sensing signal generator, including a pad (pad) for delaying the reference clock signal when the object touches or adjacent to the pad, and output the sensing signal.

The delay time calculation unit of the aforementioned sensing data output unit may include: a delay chain unit, including a plurality of delay elements connected in series, for outputting a plurality of delay signals with different delay times in response to a reference signal , And a repetitive counting signal for indicating the number of feedback times of the reference signal; an edge detector for outputting a reset signal in response to the reference signal, and outputting a counting stop signal in response to the sensing signal, and responding to these delays A code signal is output based on the number of edges of the signal; and a decoder is used to decode the repetition count signal and the code signal, and output delay data corresponding to the delay time difference between the sensing signal and the reference signal.

The delay chain unit of the aforementioned delay time calculation unit may include: a switch for performing a logical sum operation on these delay signals, counting stop signals, and a feedback signal, and outputting a first delay signal of these delay signals; The delay chain includes these delay elements to receive the first delayed signal and delay the first delayed signal, and respectively output a corresponding one of the delayed signals; an inverter for inverting the last one of these delay elements The last delay signal output by the delay element, and the feedback signal is output; and a counter is reset in response to the reset signal, and counts the edges of the feedback signal to generate a repeat counting signal, and the response counting stops Signal and output a repeat count signal to the decoder.

The measuring device of the above-mentioned sensor may include: a filter unit for receiving sensing data and outputting a sensed value; an intensity measuring device for using the sensor when it is not touched or not nearby The measured value is used to change and output the first intensity value without changing the second intensity value, and the sensing value is used to change and output the second intensity value without changing the first intensity value in the state of touch or proximity; And a decider for receiving the first intensity value and the second intensity value to calculate the threshold value, comparing the threshold value and the sensing value to determine whether there is a touch or proximity, and outputting an output signal.

The filtering unit of the above-mentioned measuring device may include: a first linear filter that receives the sensing data at a first sampling rate, eliminates noise from the sensing data, and outputs a first filtered data; The nonlinear filter is used to receive the first filter data, and limit the variation to a predetermined range or combine multiple samples, and output a second filter data; and a second linear filter to reduce Receive the second filtered data at a second sampling rate of the first sampling rate, remove noise from the second filtered data, and output the sensed value.

The above-mentioned first linear filter and second linear filter can each be a low-pass filter (LPF) or a band-pass filter (BPF).

When the first intensity value is 0, the aforementioned intensity measuring device can change the first intensity value to a sensing value, and when the second intensity value is 0, the aforementioned intensity measuring device can change the second intensity value from A value obtained by adding a preset first value and a sensed value.

According to an embodiment, when the sensing value changes within a preset first time under the state of not being touched or not being close to, the intensity measuring device can maintain the first intensity value, and when the sensing value is at When there is no change in the first time, the intensity measuring device can change the first intensity value to a sensed value. According to another embodiment, when the second intensity value is less than a preset second value in the state of being not touched or not adjacent, the intensity measuring device can maintain the first intensity value, and when the second intensity value is When it is greater than the second value, the intensity tester can change the first intensity value to a sensed value. According to yet another embodiment, when the difference between the first intensity value and the sensed value is less than a preset third value in the state of not being touched or not adjacent, the intensity measuring device can maintain the first The intensity value, and when the difference between the first intensity value and the sensed value is greater than the third value, the intensity tester can change the first intensity value to the sensed value. In the above embodiment, when the first intensity value is greater than the sensed value, the intensity tester can change the first intensity value to the sensed value or change the first intensity value from the preset fourth value to the first intensity value. When the first intensity value is less than the sensing value, the intensity measuring device can change the first intensity value to a value obtained by subtracting the fourth value from the first intensity value.

According to an embodiment, when the sensing value changes within a preset second time under the touch or proximity state, the intensity measuring device can maintain the second intensity value, and when the sensing value is within the second time When there is no change, the intensity measuring device can change the second intensity value to the sensed value. According to another embodiment, in the touch or proximity state, when the second intensity value is greater than the value obtained by adding a preset fifth value and the first intensity value, the intensity measuring device can set the second intensity The value is changed to the sensed value, and when the second intensity value is less than the value obtained by adding the fifth value and the first intensity value, the intensity measuring device can change the second intensity value from the fifth value to the first intensity value The value obtained by adding the values.

The above-mentioned determiner of the measuring device may include: a threshold value calculator for receiving the first intensity value and the second intensity value, and calculating the threshold value; and a touch decision device for comparing the threshold value and sensing Value to determine whether there is touch or proximity, and output an output signal according to the determination result.

According to an embodiment, the threshold value may include a first threshold value obtained by adding a preset first offset value and a threshold value, and a threshold value minus a preset second offset value. A second critical value of, and the critical value calculator can output the first critical value and the second critical value. At the same time, the touch decision maker can determine whether there is touch or proximity when the sensing value becomes greater than the first threshold when it is not touched or not adjacent, and in the state of touch or proximity When the sensing value becomes smaller than the second critical value, it is determined that it is not touched or not adjacent.

According to another embodiment, the aforementioned decision maker can determine that there is a touch or proximity when the sensing value is greater than a threshold value for a third period of time when it is not touched or not adjacent, and is touched or adjacent. In the touched or adjacent state, when the sensing value is less than the critical value for a fourth time, it is determined that it is not touched or not adjacent, wherein the fourth time is less than the third time.

According to another embodiment, the aforementioned decision maker can receive the first intensity value, the second intensity value, and the sensed value, and when the sensed value becomes larger than the preset value when it is not touched or not in proximity When a sixth value is added to the first intensity value, it is determined that there is touch or proximity, and in the state of touch or proximity, when the sensing value becomes smaller than the second intensity value minus the preset When the value is obtained from a seventh value of, it is determined that it is not touched or not adjacent.

The measuring device of the above-mentioned sensor may further include an activity detector for receiving the sensed value, and when the sensed value is within a preset range of a preset time, it is determined that the sensor is inactive, and Enable a control signal. When the control signal is enabled, the intensity measuring device and/or the decision maker stop operating. In this case, the sensor can output the control signal externally and control the operation of an external input device.

The detector of the above-mentioned sensor may further include an activity detector for receiving the output signal, detecting whether tapping occurs, and generating a wake-up signal when the tapping occurs. In this case, the sensor can output the wake-up signal externally and wake up an external input device.

Another aspect of the present invention provides a sensing method, including: a sensing value calculation step, calculating a sensing value that varies according to the touch or proximity of an object; an initialization step, when a first intensity value is 0 When the first intensity value is changed to a sensed value, when a second intensity value is 0, the second intensity value is changed to a value obtained by adding a preset first value and the sensed value; The first intensity value changing step is to receive the sensed value and change the first intensity value when it is not touched or not in proximity; a second intensity value change step is to receive the sensed value in the touched or neighboring state Measure the value and change the second intensity value; a critical value calculation step, receive the first intensity value and the second intensity value, and calculate a critical value; and, a recognition step, compare the sensing data with the critical value, and identify the touch Touch or close.

The above-mentioned sensing value can correspond to an impedance that varies according to the touch or proximity of the object. On the other hand, the above-mentioned sensing value may correspond to a delay time difference between a reference signal and a sensing signal, wherein the sensing signal will be delayed with the reference signal when the object is touched or approached.

According to an embodiment, the above-mentioned first intensity value changing step may include maintaining the first intensity value when the sensed value changes within a preset first time, and when the sensed value is not within the first time When a change occurs, the first intensity value is changed to a sensed value. According to another embodiment, the step of changing the first intensity value may include maintaining the first intensity value when the second intensity value is less than a preset second value, and when the second intensity value is greater than the second value , Change the first intensity value to the sensed value. According to another embodiment, the above-mentioned first intensity value changing step may include maintaining the first intensity value when the difference between the first intensity value and the sensing value is less than a preset third value, and when When the difference between the first intensity value and the sensed value is greater than the third value, the first intensity value is changed to the sensed value. According to the above-mentioned embodiment, the above-mentioned first intensity value changing step may include, when the first intensity value is greater than the sensed value, changing the first intensity value to the sensed value or changing the first intensity value to a preset value. A value obtained by adding a fourth value and a first intensity value, and when the first intensity value is less than the sensing value, the first intensity value is changed to a value obtained by subtracting the fourth value from the first intensity value.

According to an embodiment, the above-mentioned second intensity value changing step may include maintaining the second intensity value when the sensed value changes within a preset second time, and when the sensed value is not within the second time When a change occurs, the second intensity value is changed to a sensed value. According to another embodiment, the above-mentioned second intensity value changing step may include changing the second intensity value when the second intensity value is greater than a value obtained by adding a preset fifth value to the first intensity value For the sensing value, when the second intensity value is less than the value obtained by adding the fifth value and the first intensity value, the second intensity value is changed to the value obtained by adding the fifth value and the first intensity value .

According to an embodiment, the above-mentioned identification step may include, when the sensing value is greater than the threshold for a third period of time when the sensing value is greater than the threshold value for a third time in the state of not being touched or not being adjacent, then determining that it is a touched or adjacent state, And, in the touched or adjacent state, when the sensing value is less than the critical value for a fourth time, it is determined as a non-touched or non-adjacent state, wherein the fourth time is less than the third time. According to another embodiment, the above-mentioned threshold value may include a first threshold value and a second threshold value, and the above-mentioned threshold value calculation step may include, by adding a preset first offset value and a threshold value To calculate the first threshold value, the second threshold value is calculated by subtracting a preset second offset value from the threshold value, and the above identification step may include, in the state of not being touched or not adjacent , When the sensing value becomes greater than the first critical value, it is determined to be in the state of touch or proximity, and in the state of touch or proximity, when the sensing value becomes less than the second threshold, it is determined to be not The state of being touched or not adjacent.

Another aspect of the present invention provides a filter for a sensor, including: a first linear filter that receives a sensing data that varies according to touch or proximity at a first sampling rate, and eliminates the sensor Measure the noise of the data, and output a first filter data; and, a second filter, which is connected in series with the first linear filter, is used to receive the first filter data, filter the first filter data, and output One second filtering data.

According to an embodiment, the above-mentioned second filter may be a non-linear filter for receiving the first filtered data, limiting the variation to one sample or a combination of multiple samples, and outputting the second filtered data . According to another embodiment, the above-mentioned second filter may be a second linear filter that receives the first filtered data at a second sampling rate lower than the first sampling rate, and removes the filtering data from the first filtered data. Noise, and output the second filtering data.

The above-mentioned filter may include a first linear filter, a nonlinear filter, and a second linear filter, wherein the second linear filter receives the second filtered data at a second sampling rate lower than the first sampling rate , And remove the noise from the second filtering data, and output a sensed value.

The above-mentioned first linear filter and second linear filter may each be a low-pass filter or a band-pass filter.

Hereinafter, the sensor, the sensing method of the sensor, and the filter of the sensor according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates the structure of a sensor according to an embodiment of the invention. The sensor includes a sensing data output unit 10 and a touch measuring device 300, and the sensing data output unit 10 includes a sensing signal output unit 100 and a delay time calculation unit 200.

The function of the block shown in Figure 1 will be described as follows.

The sensing data output unit 10 outputs a sensing data that changes according to a touch of a touch object. The sensing signal output unit 100 outputs a reference signal ref and a sensing signal sen delayed with the reference signal ref according to the touch of the touch object. The delay time calculation unit 200 detects a delay time difference between the sensing signal sen and the reference signal ref, and outputs a delay data corresponding to the delay time difference as the sensing data Ddata.

The touch monitor 300 uses the sensing data Ddata to determine the touch of the touch object, and based on the determination result, outputs a touch signal touch to indicate whether the touch has occurred. In particular, the touch monitor 300 uses the sensing data Ddata to change a threshold value. When the sensing data Ddata is greater than the threshold, it is determined that a touch has occurred, and when the sensing data Ddata is less than the threshold, it is determined that the touch has not occurred. Touch, and output the touch signal touch according to whether the touch has occurred. The threshold can be calculated using a first intensity value or/and a second intensity value. The first intensity value is the intensity value when the touch does not occur, and it can correspond to the delay time difference between the sensing signal sen and the reference signal ref in the untouched state. The second intensity value is the intensity value in the touch state, and it can correspond to the delay time difference between the sensing signal sen and the reference signal ref. The first intensity value and the second intensity value can be calculated by the touch monitor 300 using the sensing data Ddata. Similarly, the threshold may include a first threshold and a second threshold. The touch monitor 300 can be configured to determine that a touch has occurred when the sensing data Ddata is greater than a first threshold value, and determine that a touch has not occurred when the sensing data Ddata is less than a second threshold value.

Although not shown in the figure, the sensing data output unit can measure the impedance (such as capacitance) that changes according to the touch of the touch object, and output the corresponding measured impedance (such as capacitance) A value of is used as the sensing data Ddata.

FIG. 2 illustrates the structure of a sensing signal output unit of the sensor shown in FIG. 1 according to an embodiment of the present invention. The sensing signal output unit includes a reference clock generator 110, a sensing signal generator 120, and a reference signal generator 130. The sensing signal generator 120 includes a resistor R1 and a pad pad, and the reference signal generator 130 includes a resistor R2.

The function of the block shown in Figure 2 will be described as follows.

The reference clock generator 110 outputs a reference clock signal clkr. The sensing signal generator 120 delays the reference clock signal clkr, and outputs the delayed reference clock signal clkr as the sensing signal sen when the touch object touches the pad pad, and when the touch object is not touched The reference clock signal clkr is outputted as the sensing signal sen without delaying the reference clock signal clkr when the pad is pad. In particular, when a touch object with a preset capacitance touches the pad pad, the reference clock signal clkr provided to the sensing signal generator 120 will be delayed for a certain period of time due to the resistance R1 and the capacitance of the touch object , And is output as the sensing signal sen. In contrast, when no touch object touches the pad pad, the reference clock signal clkr is not delayed and is output as the sensing signal sen. The reference signal generator 130 does not delay the reference clock signal clkr transmitted by the reference clock generator 110, and outputs the reference clock signal clkr as the reference signal ref.

Although not shown in the figure, the reference signal generator 130 may further include a capacitor connected between one end of the reference signal ref outputting the reference signal ref and a ground voltage, so as to delay the reference irrespective of the touch of the touch object. The clock signal clkr is for a predetermined time, and the delayed reference clock signal is output as the reference signal ref.

FIG. 3 illustrates the structure of a delay time calculation unit of the sensor of FIG. 1 according to an embodiment of the present invention. The delay time calculation unit includes a delay chain unit 210, an edge detector 220, and a decoder 230. The delay chain unit 210 includes a switch ASW composed of a 3-input AND gate, a plurality of delay elements D1 to Dn connected in series with each other, an inverter INV, and a counter CNT.

The function of the block shown in Figure 3 will be described as follows.

The delay chain unit 210 responds to the reference signal ref, and outputs a plurality of delay signals delay0, delay1... and a repeat count signal iter with different delay times. The repetition count signal iter indicates the number of times the reference signal ref is fed back through the delay chain unit 210. The switch ASW responds to the reference signal ref, a feedback signal fb, and a counting stop signal stop, and outputs a delay signal delay0 (for example, the first delay signal among a plurality of delay signals) as an input signal. In particular, the switch ASW performs a logical AND operation (logical AND operation) on the reference signal ref, the feedback signal fb, and the counting stop signal stop. operation), and generate a delay signal delay0, and output a delay signal delay0 as an input signal to the delay chain unit 210 having delay elements D1 to Dn. The delay elements D1 to Dn delay the input delay signal delay0, and respectively output delay signals delay1, delay2, ..., delayn. The inverter INV inverts the delay signal delayn output by the last delay element Dn in the delay chain unit 210 (for example, the last delay signal among the plurality of delay signals), and outputs the feedback signal fb. The counter CNT responds to the feedback signal fb and outputs a repeat count signal iter, where the repeat count signal iter is used to indicate the number of times the reference signal ref is fed back through the delay chain unit 210. In particular, the counter CNT counts the edges of the feedback signal fb obtained by the inverted delay signal delayn, and outputs the repeat count signal iter. That is, the counter CNT will be reset in response to a reset signal rest output by the edge detector 220, and stop counting in response to the counting stop signal stop output by the edge detector 220, and output the repeat counting signal iter to decodeDevice230. In addition, the counter CNT can be reset in response to the counting stop signal stop output by the edge detector 220.

In other words, the delay chain unit 210 will start to operate in response to the reference signal ref used to indicate the start of the calculation of the delay time. The delay chain unit 210 receives the delay signal delay0 generated by the reference signal ref, the feedback signal fb and the counting stop signal stop through logic and operation, and delays the delay signal delay0 by a preset time, and the output has different delays Multiple time delay signals delay1, delay2,..., delayn. The counter CNT will output a repeat count signal iter. At the same time, the delay chain unit 210 will stop the operation in response to the counting stop signal stop output by the edge detector 220.

The edge detector 220 outputs a reset signal reset in response to the reference signal ref, and outputs a counting stop signal stop in response to the sensing signal sen, and counts the edges of the delay signals delay0, delay1,..., delayn-1, and responds to delay The number of edges of the signals delay0, delay1,..., delayn-1 output a code signal code. At the same time, the edge detector 220 is reset in response to the repeat count signal iter. In other words, when the value of the repeat count signal iter is changed, the edge detector 220 is reset.

The decoder 230 decodes the code signal code output by the edge detector 220 and the repetition count signal iter output by the counter CNT, generates delay data, and outputs the delay data as the sensing data Ddata.

In addition to the embodiment shown in FIG. 3, the delay time calculation unit 200 may be constructed in various other ways. For example, the switch ASW can be realized by a switch circuit, wherein the switch circuit selectively outputs a reference signal ref and a feedback signal fb in response to a repetitive counting signal iter. At the same time, the counter CNT and the decoder 230 can be ignored from the delay time calculation unit 200 in FIG. 3, and the edge detector 220 can start counting the delay signals delay0, delay1,..., delayn-1 in response to the reference signal ref In response to the sensing signal sen, the count of the number of edges of each delay signal delay0, delay1,..., delayn-1 is stopped, and the output corresponds to the delay signal delay0, delay1,..., delayn- Delay data of the number of edges of 1. In addition, the edge detector 220 can be replaced by a code generator including multiple mutually exclusive or gates and multiple AND gates. The mutual exclusion or gate can output the delay signal delay0, delay1,..., delayn-1 as it is in response to the repeated counting signal iter or invert the delay signal delay0, delay1,..., delayn-1 and output the inverted signal. The signal after the phase is used as the comparison signal. At the same time, the AND gate can perform logical AND (AND) operation on each comparison signal and the sensing signal sen, and respectively output code signals code. In addition, although FIG. 3 illustrates the delay chain unit 210 with a feedback architecture, a delay chain without a feedback architecture can also be used.

2 and 3 illustrate the delayed touch sensor, but the invention is not limited to this. In other words, the present invention can also be applied to a sensor capable of sensing impedance (for example, capacitance) that changes according to touch. In this embodiment, the delay time calculation unit 200 can be replaced by an impedance measurement unit, wherein the impedance measurement unit uses a pad to measure impedance (e.g., capacitance), and the measured impedance (e.g., : Capacitance) is converted into a digital value, and the digital value is output. The impedance measurement unit can be provided in a variety of ways. For example, the impedance measuring unit can measure a charging or discharging time determined by the impedance (such as a capacitance) that changes according to the touch, convert the charging or discharging time into a digital value, and output the digital value. In this embodiment, a delta-sigma analog-to-digital converter can be used to convert the charging or discharging time into a digital value.

FIG. 4 illustrates the structure of the touch detector of the sensor of FIG. 1 according to an embodiment of the present invention. The touch tester 300 includes a filter unit 310, an intensity tester 320, and a decision maker 330.

The function of the block shown in Figure 4 will be described as follows.

The filtering unit 310 is used for filtering the sensing data Ddata generated by the delay time calculating unit 200 and outputting a delay value CD. The filtering unit 310 includes a low-pass filter or a band-pass filter, and is used to filter out noise. When the touch object does not touch the pad pad, the intensity measurer 320 uses the delay value CD output by the filter unit 310 to change an intensity value (that is, when the touch object is not touched, it corresponds to the difference between the sensing signal sen and the reference signal ref. The delay time difference between the first intensity value NTS), and when the touch object touches the pad pad, the delay value CD is used to change an intensity value (that is, when the touched state corresponds to the sensing signal sen and the reference signal ref The delay time difference between the second intensity value TS), and the first intensity value NTS and the second intensity value TS are output. On the other hand, the intensity measurer 320 can respond to the touch signal touch output by the decision maker 330 to determine whether a touch has occurred. The decision maker 330 uses the delay value CD output by the filter unit 310 and the first intensity value NTS and the second intensity value TS output by the intensity measurer 320 to determine that a touch has occurred, and outputs a touch signal touch to indicate whether A touch has occurred. In particular, the decision maker 330 uses the first intensity value NTS and the second intensity value TS output by the intensity measurer 320 to determine a critical value, and compares the critical value with the delay value CD output by the filtering unit 310. Therefore, the decision maker 330 can determine that a touch has occurred when the delay value CD is greater than or equal to the critical value, and determine that no touch has occurred when the delay value CD is less than the critical value.

Although not shown in the figure, according to individual cases, the filter unit 310 of the touch monitor 300 can output the sensing data Ddata as the delay value CD without filtering. In other words, the intensity measurer 320 and the decision maker 330 can use the sensing data Ddata output by the delay time calculation unit 200 as the delay value CD.

In summary, although FIG. 4 illustrates a delay type touch sensor, the present invention can also be applied to a sensor capable of measuring impedance (for example, capacitance). In this embodiment, the filter unit 310 can receive the sensing data Ddata. The sensing data Ddata is obtained by converting the measured impedance (such as capacitance) into a digital value instead of corresponding to the sensing signal sen The filtering unit 310 further outputs a sensed value obtained by removing noise from the sensed data Ddata for the delayed data of the delay time difference between the reference signal ref and the reference signal ref. At the same time, the intensity measurer 320 can use the sensing value output by the filtering unit 310 to change the first intensity value NTS and the second intensity value TS.

FIG. 5 shows the structure of the filter unit of the touch monitor 300 of FIG. 4 according to an embodiment of the present invention. The filtering unit 310 includes a first linear filter 311, a non-linear filter 312, and a second linear filter 313.

The function of the block shown in Figure 5 will be described as follows.

The first linear filter 311 samples a kind of delayed data Ddata at a first sampling rate (for example, 100KHz), removes noise from the delayed data Ddata, and outputs a first filtered data data1. The non-linear filter 312 can receive the first filter data data1 at a predetermined sampling rate, limit the variation to a predetermined range, and output a second filter data data2. On the other hand, the non-linear filter 312 can be replaced by an arithmetic unit like accumulation. For example, the non-linear filter 312 receives the first filtered data data1, combines multiple samples (for example, 8 or 64 samples), and outputs the second filtered data data2. On the other hand, the non-linear filter 312 can execute all the above-mentioned procedures and output the second filtering data data2. The second linear filter 313 samples the second filtered data data2 at a second sampling rate (for example, 1KHz) lower than the first sampling rate, removes noise from the second filtered data data2, and outputs a delay value CD. Controlling the sampling rate of the second linear filter 313 to be less than the sampling rate of the first linear filter 311 can prevent beating caused by interference signals.

In FIG. 5, the first linear filter 311 and the second linear filter 313 may be a low-pass filter to remove high frequency components from the sensing data Ddata and the second filtering data data2, respectively. According to individual cases, either or both of the first linear filter 311 and the second linear filter 313 can also be a band-pass filter to filter out interference of a specific frequency.

Although not shown in the figure, the filter unit 310 of the touch monitor 300 may only include part of the first linear filter 311, the nonlinear filter 312, and the second linear filter 313. In this case, the first filter data data1 or the second filter data data2 can be output as the delay value CD.

In other words, with the use of the filter unit 310 in FIG. 5, the intensity measurer 320 can determine the first intensity value NTS and the second intensity value TS based on the accurate delay value CD. Although a delayed touch sensor is listed, the filter unit 310 shown in FIG. 5 can also be applied to a touch sensor capable of measuring impedance (for example, capacitance). In this case, the sensing value output by the filtering unit 310 may not be the delay value CD corresponding to the delay time difference between the reference signal ref and the sensing signal sen, but may correspond to the measured impedance (for example: Capacitance) value.

FIG. 6 is a flowchart illustrating a method for determining the first intensity value NTS of the intensity measuring device 320 of the touch measuring device 300 of the sensor of the invention in FIG. 4 according to an embodiment of the invention.

The method of determining the first intensity value NTS by the intensity measuring device 320 will be described below with reference to FIG. 6.

First, in step S11, the intensity measuring device 320 determines whether the current first intensity value NTS is zero. When the current first intensity value NTS is 0, the intensity measurer 320 will store the current delay value CD received from the filtering unit 310 as the new first intensity value in step S12. When a power supply voltage is initially provided or the sensor is reset, the first intensity value NTS may be zero. In this case, the first intensity value NTS can be initialized to the current delay value CD.

Next, in step S13, the intensity measuring device 320 responds to the touch signal touch output by the decision maker 330 of the touch measuring device 300 to determine whether the touch sensor is in a touch state. When the touch sensor is in the touched state, because it is unnecessary to change the first intensity value to indicate the intensity value that is not in the touched state, the intensity measurer 320 will maintain the current first intensity in step S17 Value NTS.

When the determination in step S13 is that the touch sensor is not in a touch state, the intensity measurer 320 determines in step S14 whether the delay value CD output by the filtering unit 310 is within a preset first time (for example: About 12 milliseconds). When the delay value CD changes within the first time, the intensity measurer 320 maintains the current first intensity value NTS in step S17. Accordingly, the intensity measuring device 320 can prevent the first intensity value NTS from being changed due to changes in the delay value CD caused by the surrounding noise, and when the delay value CD in the untouched state is changed due to environmental changes (for example, temperature) Or when the thickness of the cover changes and changes occur, the first intensity value NTS can be modified.

In step S15, the intensity measuring device 320 determines whether the second intensity value TS indicating the intensity value in the touch state is less than the preset first value D1. When the second intensity value TS is less than the first value D1, the intensity measurer 320 maintains the current first intensity value NTS in step S17. Accordingly, the intensity measurer 320 can be configured to modify the first intensity value NTS only after the second intensity value TS becomes greater than the first value D1.

In step S16, the intensity measurer 320 determines whether the difference between the delay value CD output by the filtering unit 310 and the first intensity value NTS is less than a preset second value D2. When the difference between the delay value CD and the first intensity value NTS is less than the second value D2, the intensity measurer 320 maintains the current first intensity value NTS in step S17. In other words, when the difference between the delay value CD and the first intensity value NTS is smaller than the second value D2, because the influence of external factors is not important, the intensity measurer 320 can maintain the current first intensity value NTS.

When the difference between the delay value CD and the first intensity value NTS is greater than the second value D2, the intensity measurer 320 will add a preset third value D3 to the current first intensity value NTS in step S18 , Or subtract the third value D3 from the current first intensity value NTS, and store the obtained value as the new first intensity value NTS. In particular, when the delay value CD is greater than the first intensity value NTS according to the second value D2 or other values, the intensity measurer 320 will store the value obtained by adding the third value D3 to the current first intensity value NTS to As the new first intensity value NTS. At the same time, when the delay value CD is smaller than the first intensity value NTS or other values according to the second value D2, the intensity measuring device 320 will store the value obtained by subtracting the third value D3 from the current first intensity value NTS as The new first intensity value NTS.

Fig. 6 illustrates an embodiment where the intensity measurer 320 sequentially determines whether the delay value CD in step S14 changes within a preset first time, and in step S15 whether the second intensity value TS is less than the preset first time. A value D1, and whether the difference between the delay value CD and the first intensity value NTS in step S16 is smaller than the preset second value D2. However, in another embodiment, the intensity tester 320 may only accept one of steps S14 to S16, and maintain or change the first intensity value NTS. For example, the intensity measurer 320 may only determine whether the delay value CD changes within the first time, and maintain the first intensity value NTS when the delay value CD changes within the first time, and when the delay value CD is not in the first time. Modify the first intensity value NTS when the time changes. At the same time, the sequence of step S14 to step S16 is not limited to the above-mentioned embodiment, and can be changed.

At the same time, FIG. 6 illustrates an embodiment, where the first intensity value NTS is changed by adding the third value D3 and the current first intensity value NTS, or the current first intensity value NTS and the third value D3 The subtraction. However, the intensity tester 320 can store the current delay value CD as the new first intensity value NTS.

FIG. 7 is a timing diagram for explaining the method of determining the first intensity value NTS by the intensity measuring device 320 of the touch measuring device 300 of the sensor of the present invention in FIG. 6. In particular, FIG. 7 illustrates a case where steps S15 and S16 are omitted from the method of FIG. 6, and the current delay value CD in step S18 of FIG. 6 is stored as the new first intensity value NTS. In FIG. 7, the delay value CD output by the filtering unit 310 is represented by a dotted line, and the first intensity value NTS is represented by a solid line.

The method of determining the first intensity value NTS of the intensity measuring device 320 will be described below with reference to FIG. 7.

At a first time point t1, because the delay value CD does not change during the first time T1, the intensity measurer 320 uses the delay value CD stored at the first time point t1 as the new first intensity value NTS. After that, because the delay value CD is not maintained for the first time T1 before the second time point t2, the intensity measuring device 320 does not change the first intensity value NTS. At the second time point t2, because the delay value CD has not changed within the first time T1, the intensity measurer 320 will again use the delay value CD stored at the second time point t2 as the new first intensity value NTS. After the second time point t2, the delay value CD rises sharply, that is, the touch sensor is in a touch state. Therefore, after the second time point t2, the intensity meter 320 will not change the first intensity value NTS.

FIG. 8 is a flowchart illustrating a method for determining the second intensity value TS of the intensity measuring device 320 of the touch measuring device 300 of the sensor of the invention in FIG. 4 according to an embodiment of the invention.

The method of determining the second intensity value TS will be explained with reference to FIG. 8 as follows.

First, in step S21, the intensity measuring device 320 determines whether the second intensity value TS is zero. When the second intensity value TS is 0, the intensity measurer 320 will store the value obtained by adding a preset fourth value D4 to the first intensity value NTS in step S22 as the new second intensity value TS. When a power supply voltage is initially provided or the sensor is reset, the second intensity value TS may be zero. In this case, the second intensity value TS may be initialized to a value obtained by adding the preset fourth value D4 and the first intensity value NTS.

Next, in step S23, the intensity measuring device 320 will respond to the touch signal touch output by the decision maker 330 to determine whether the touch sensor is in a touch state. When the touch sensor is not in the touched state, because it is unnecessary to change the second intensity value TS to indicate the intensity value in the touched state, the intensity measurer 320 will maintain the current state in step S26. The second intensity value TS.

In step S24, the intensity measurer 320 determines whether the delay value CD output by the filtering unit 310 changes within a preset second time (for example, 7 milliseconds). When the delay value CD changes within the second time, the intensity measurer 320 maintains the current second intensity value TS in step S26. Accordingly, the intensity measuring device 320 can prevent the second intensity value TS from being changed due to changes in the delay value CD caused by the surrounding noise, and when the delay value CD in the touch state is changed due to environmental changes (for example, temperature) or It can modify the second intensity value TS when the thickness of the cover changes. The second time can be controlled to be less than the first time mentioned in step S16 of FIG. 6. In other words, the second intensity value TS will be modified in the touch state as described above. Because the noise is caused by the touched object in the touched state, compared to when the intensity meter 320 determines that the first intensity value NTS changes in the untouched state, the specific delay value CD must be maintained at Shorter time.

In step S25, the intensity measurer 320 determines whether the second intensity value TS is less than a value obtained by adding a preset fifth value D5 to the first intensity value NTS. In other words, the intensity measurer 320 determines whether the difference between the first intensity value NTS and the second intensity value TS is greater than the preset fifth value D5. When the second intensity value TS is less than the value obtained by adding the fifth value D5 and the first intensity value NTS, the intensity measuring device 320 stores the sum of the fifth value D5 and the first intensity value NTS in step S28 The obtained value is used as the new second intensity value TS. Accordingly, the intensity measurer 320 can determine the first intensity value NTS and the second intensity value TS, so that the difference between the first intensity value NTS and the second intensity value TS becomes the fifth value D5 or other values.

When the second intensity value TS is greater than the value obtained by adding the fifth value D5 and the first intensity value NTS, the intensity measurer 320 will store the current delay value CD as the second intensity value TS in step S27.

In another embodiment, the intensity measuring device 320 can omit step S25 and step S28 from the process of FIG. 8. In particular, the intensity measurer 320 can only determine whether the touch object in step S23 is touched and whether the delay value CD in step S24 is changed, so as to maintain the current second intensity value TS or store the current delay value CD As the new second intensity value TS.

FIG. 9 is a timing diagram for explaining the method of determining the second intensity value TS shown in FIG. 8. In particular, FIG. 9 illustrates a case where steps S25 and S28 are omitted from the method in FIG. 6. In FIG. 9, the delay value CD output by the filtering unit 310 is represented by a dotted line, and the second intensity value TS is represented by a solid line.

The method of determining the second intensity value TS will be described below with reference to FIG. 9.

At the first time point t1, because the delay value CD does not change within the preset second time T2, the intensity measurer 320 stores the delay value CD at the first time point t1 as the new second intensity value TS. After that, because the delay value CD is not maintained for the second time T2 before the second time point t2, the intensity meter 320 will not change the second intensity value TS. At the second time point t2, because the delay value CD does not change during the second time T2, the intensity measurer 320 stores the delay value CD at the second time point t2 as the new second intensity value TS. After the second time point t2, the delay value CD drops sharply, that is, the touch sensor is in a non-touch state. Therefore, after the second time point t2, the intensity meter 320 does not change the second intensity value TS.

As described above, when the power supply voltage is initially supplied or the sensor is reset, the first intensity value NTS and the second intensity value TS will each become zero. In this case, the first intensity value NTS will be initialized to the current delay value CD (refer to step S12 in FIG. 6), and the second intensity value TS will be initialized to be the same as the fourth value D4 and the first intensity value NTS. Add the obtained value (refer to step S22 in FIG. 8). Therefore, when the power supply voltage is initially provided or the sensor is reset, a threshold value can be calculated based on the initial first intensity value NTS and the second intensity value TS, and can be compared with the delay value CD to determine the touch Control whether the object is in a touch state (refer to step S13 in FIG. 6 and step S23 in FIG. 8).

Although FIGS. 6 to 9 illustrate delay type touch sensors, the present invention can also be applied to sensors capable of measuring impedance as described above. In this case, as described above, the intensity measurer 320 uses the value corresponding to the measured impedance to replace the delay value CD corresponding to the delay time difference between the reference signal ref and the sensing signal sen to determine the first intensity The value NTS and the second intensity value TS.

FIG. 10 shows the structure of the decision maker 330 of the touch monitor 300 shown in FIG. 4 according to an embodiment of the present invention. The decision maker 330 includes a threshold calculator 331 and a touch decision maker 332.

The function of the block shown in Fig. 10 will be described as follows.

The threshold value calculator 331 receives the first intensity value NTS and the second intensity value TS from the intensity measurer 320, calculates a threshold value Th_value, and outputs the threshold value Th_value. The threshold Th_value can be obtained using Equation 1.

<maths><img file="TW201014175A_D0001.tif" /></maths>

The touch decision maker 332 receives the threshold Th_value output by the threshold calculator 331 and the delay value CD output by the filter unit 310, determines whether the touch sensor is in a touch state, and outputs the touch signal touch To indicate whether a touch has occurred.

For example, the touch decision maker 332 may determine that a touch has occurred when the delay value CD is greater than the threshold Th_value according to a preset third time or a longer time, and may determine that a touch has occurred according to a preset fourth time or A longer time and when the delay value CD is less than the threshold Th_value, it is determined that no touch has occurred. In this case, in order to prevent the touch decision maker 332 from mistakenly not being touched as a touch due to noise, the third time can be controlled to be greater than the fourth time. For example, the third time may be 10 milliseconds, and the fourth time may be 4 milliseconds. On the other hand, the touch decision maker 332 can refer to the value obtained by adding the preset first offset value Dh1 and the threshold value Th_value to determine that a touch has occurred when the delay value CD is greater than the threshold value Th_value, and can refer to The value obtained by subtracting the preset second offset value Dh2 from the threshold value Th_value determines that no touch occurs when the delay value CD is less than the threshold value Th_value. On the other hand, the touch decision maker 332 can use a combination of the above two methods to determine whether a touch has occurred.

In another state, the touch decision maker 332 can be simply constructed to determine that a touch has occurred when the delay value CD is greater than the threshold Th_value, and determine that no touch has occurred when the delay value CD is less than the threshold Th_value.

Although not shown in the figure, the threshold calculator 331 can further output a first threshold Th_value1 and a second threshold Th_value2. The first threshold Th_value1 can be obtained by adding the first offset value Dh1 and the threshold Th_value, and the second threshold Th_value2 can be obtained by subtracting the second offset value Dh2 from the threshold Th_value. The first offset value Dh1 may be equivalent to the second offset value Dh2. On the other hand, the first threshold Th_value1 can be obtained by adding the first offset value Dh1 and the first intensity value NTS, and the second threshold Th_value2 can be obtained by subtracting the second threshold value from the second intensity value TS. Th_value2 is obtained.

Although not shown in the figure, the touch decision maker 332 can directly receive the first intensity value NTS and the second intensity value TS from the intensity measurer 320, and receive the delay value CD from the filter unit 310, and refer to the preset Value or in the untouched state and when the delay value CD is greater than the first intensity value NTS, it is determined that a touch has occurred, and refer to the preset value or in the touched state when the delay value CD is less than the second intensity value TS When it is determined that no touch has occurred. When only the touch decision maker 332 in the above manner decides whether a touch has occurred, the threshold calculator 331 can be omitted from the decision maker 330 shown in FIG. 10. At the same time, the touch decision maker 332 can use a combination of the above methods to determine whether a touch has occurred.

FIG. 11 is a timing diagram for explaining the operation of the decision maker 330 shown in FIG. 10. In FIG. 11, the first intensity value NTS is represented by alternate long-short dashed lines, the second intensity value TS is represented by a double-dot chain line, and the delay value CD is represented by a solid line. The decider 330 may determine that the touch has occurred when the delay value CD is greater than the first threshold Th_value1, and may determine that no touch has occurred when the delay value CD is less than the second threshold Th_value2.

The operation of the decision maker 330 shown in FIG. 10 will be explained with reference to FIG. 11 as follows.

Because the delay value CD is less than the first threshold Th_value1 before the first time point t1, the decision maker 330 determines that no touch has occurred, and outputs the corresponding touch signal touch, such as logic-low. Because the delay value CD becomes greater than the first threshold Th_value1 at the first time point t1, the decision maker 330 determines that a touch has occurred, and outputs the corresponding touch signal touch, such as logic-high. Because the delay value CD is greater than the second threshold Th_value2 between the first time point t1 and the second time point t2, the decision maker 330 determines that a touch has occurred and outputs the corresponding touch signal touch. Because the delay value CD becomes smaller than the second threshold Th_value2 at the second time point t2, the decision maker 330 determines that no touch has occurred, and outputs the corresponding touch signal touch. Because the delay value CD is less than the first threshold Th_value1 between the second time point t2 and the third time point t3, the decision maker 330 determines that no touch has occurred, and outputs the corresponding touch signal touch. Because the delay value CD becomes greater than the first threshold Th_value1 at the third time point t3, the decision maker 330 determines that a touch has occurred and outputs the corresponding touch signal touch.

In the above manner, the first intensity value NTS and the second intensity value TS can be used to calculate the first threshold value Th_value1 and the second threshold value Th_value2.

FIG. 12 illustrates the structure of a touch detector of a touch sensor according to another embodiment of the present invention. A touch detector 301 includes a filter unit 310, an intensity detector 320-1, a decision maker 330-1, and an activity detector 340.

The function of the block shown in Fig. 12 will be described as follows.

The filtering unit 310 performs the same functions as described with respect to FIG. 4 and FIG. 5. The intensity measuring device 320-1 calculates and outputs the first intensity value NTS and the second intensity value TS in the same manner as described with respect to FIGS. 4 and 6-9, and responds to the control signal con output by the activity detector 340 operate. The decision maker 330-1 determines whether a touch has occurred in the same manner as described with respect to FIG. 4, FIG. 10, and FIG. 11, and outputs a touch signal touch to indicate whether a touch has occurred. The activity detector 340 receives the delay value CD output by the filter unit 310, determines whether the touch sensor is active based on the variation of the delay value CD, and outputs the control signal con based on the determination result. For example, when the delay value CD is within a predetermined range of a predetermined time, the activity detector 340 can determine that the touch sensor is inactive, and output a corresponding control signal con.

That is, according to another embodiment of the present invention, the touch detector 301 shown in FIG. 12 may further include an activity detector 340, which can output according to whether the touch sensor is active in response to a change in the delay value CD. The control signal con. At the same time, the intensity tester 320-1 and/or the decision maker 330-1 can receive the control signal con from the activity detector 340 and operate only when the touch sensor is active, thereby reducing power consumption.

Although not shown in the figure, the activity detector 340 may receive the first filter data data1 output by the first linear filter 311 of the filter unit 310 or the first filter data output by the nonlinear filter 312 of the filter unit 310 Second, filter the data data2, and determine whether the touch sensor is active.

Although not shown in the figure, the control signal con output by the activity detector 340 can be transmitted from the touch sensor to control the operation of the input device including the touch sensor. For example, when the touch sensor is inactive, the activity detector 340 can output the control signal con to enable it. In the multiple blocks of the input device including the touch sensor, it is only used to send /Receive clock synchronization aspect of the operation of the previous (preamble) block. In this state, it is possible to prevent the decrease in the response rate caused by the power drop of the input device, thereby improving the response rate of the input device.

Although not shown in the figure, the activity detector 340 may receive the touch signal touch from the decision maker 330-1 and output a wake-up signal to wake up the input device including the touch sensor. For example, when the activity detector 340 detects a tap in response to the touch signal touch, that is, when a touch is repeated more than a preset number of times, the activity detector 340 can output Wake up signal to wake up the input device.

Although an example of a touch sensor is listed above, the present invention can also be applied to a proximity sensor (proximity sensor). The proximity sensor detects objects that are close to itself or in front of it, or objects within a short distance that are not actually touched. Among various proximity sensors, a proximity sensor capable of sensing changes in impedance and recognizing neighbors is substantially similar to a touch sensor capable of sensing changes in impedance and recognizing touch. Therefore, a touch sensor capable of sensing impedance can be used as a proximity sensor by greatly increasing the sensitivity of the touch sensor. Even if the sensitivity of the touch sensor is not greatly increased, the proximity sensor can be constructed as a plurality of sensors electrically connected to each other to increase the sensing range. When the present invention is applied to a proximity sensor, the first intensity value NTS or the second intensity value TS may not change according to touch, but according to the proximity of the object, and may be based on the combination of the first intensity value NTS and the second intensity value TS. The critical value obtained by the second intensity value TS is used to determine the proximity of the object.

According to the present invention, a sensor can take into account environmental changes (for example, interference noise, detection position, coverage thickness, and/or touch pad type) without performing a tuning operation. A certain sensitivity to recognize touch.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be subject to those defined by the attached patent application scope.

<p>10. . . Sensing data output unit</p><p>100. . . Sensing signal output unit</p><p>200. . . Delay time calculation unit</p><p>300. . . Touch monitor</p><p>ref. . . Reference signal</p><p>sen. . . Sense signal</p><p>Ddata. . . Sensing data</p><p>touch. . . Touch signal</p><p>110. . . Reference clock generator</p><p>120. . . Sensing signal generator</p><p>130. . . Reference signal generator</p><p>R1, R2. . . resistance</p><p>pad. . . Gasket</p><p>clkr. . . Reference clock signal</p><p>210. . . Delay chain unit</p><p>220. . . Edge detector</p><p>230. . . decoder</p><p>ASW. . . switch</p><p>D1~Dn. . . Delay element</p><p>INV. . . inverter</p><p>CNT. . . counter</p><p>delay0~delayn. . . Delayed signal</p><p>fb. . . Feedback signal</p><p>iter. . . Repeat counting signal</p><p>stop. . . Counting stop signal</p><p>rest. . . Reset signal</p><p>code. . . Code signal</p><p>310. . . Filter unit</p><p>320. . . Strength tester</p><p>330. . . Decision maker</p><p>CD. . . Delay value</p><p>NTS. . . First intensity value</p><p>TS. . . Second intensity value</p><p>311. . . First linear filter</p><p>312. . . Non-linear filter</p><p>313. . . Second linear filter</p><p>data1. . . First filter data</p><p>data2. . . Second filter data</p><p>S11~S18. . . To illustrate the flow of each step of the embodiment in FIG. 6</p><p>T1. . . first timing</p><p>S21~S28. . . To illustrate the flow of each step of the embodiment in FIG. 8</p><p>T2. . . Second time</p><p>331. . . Critical value calculator</p><p>332. . . Touch decision maker</p><p>Th_value. . . Critical value</p><p>Th_value1. . . First critical value</p><p>Th_value2. . . Second critical value</p><p>320-1. . . Strength tester</p><p>330-1. . . Decision maker</p><p>340. . . Activity detector</p><p>con. . . control signal</p>

FIG. 1 illustrates the structure of a sensor according to an embodiment of the invention.

FIG. 2 illustrates the structure of a sensing signal output unit of the sensor of FIG. 1 according to an embodiment of the present invention.

FIG. 3 illustrates the structure of the delay time calculation unit of the sensor of FIG. 1 according to an embodiment of the present invention.

FIG. 4 illustrates the structure of the touch detector of the sensor of FIG. 1 according to an embodiment of the present invention.

FIG. 5 illustrates the structure of the filter unit of the touch monitor 300 of FIG. 4 according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating a method for determining the first intensity value NTS of the intensity measuring device 320 of the touch measuring device 300 of the sensor of the invention in FIG. 4 according to an embodiment of the invention.

FIG. 7 is a timing diagram for explaining the method of determining the first intensity value NTS by the intensity measuring device 320 of the touch measuring device 300 of the sensor of the present invention in FIG. 6.

FIG. 8 is a flowchart illustrating a method for determining the second intensity value TS of the intensity measuring device 320 of the touch measuring device 300 of the sensor of the invention in FIG. 4 according to an embodiment of the invention.

FIG. 9 is a timing diagram for explaining the method of determining the second intensity value TS shown in FIG. 8.

FIG. 10 shows the structure of the decision maker 330 of the touch monitor 300 shown in FIG. 4 according to an embodiment of the present invention.

FIG. 11 is a timing diagram for explaining the operation of the decision maker 330 shown in FIG. 10.

FIG. 12 illustrates the structure of a touch detector of a touch sensor according to another embodiment of the present invention.