TW202046072A - Signal detection method of touch device and system thereof - Google Patents

Abstract

A signal detection method of a touch device is disclosed, and the touch device has a dynamic boundary adjustment of an upper threshold and a lower threshold, and the method includes: reading a preset first threshold to set the upper threshold and the lower threshold; proceeding a scanning method to obtain a plurality of initial signals and signal value thereof; selecting a maximum signal value from a plurality of signal values of the initial signals; comparing the upper threshold to a half of the maximum signal value; adjusting the first threshold to the half of the maximum signal value if the half of the maximum signal value is more than or equal to the upper threshold; proceeding a filter method by comparing the signal values to the first threshold, and the initial signal, whose signal value is more than or equal to the first threshold, is defined as a filter signal; and, a signal processing method is dealt with the filter signal.

Description

Signal detection method and system of touch device

The invention relates to a signal detection method and system of a touch device, and more particularly to a signal detection method with a dynamically adjusted threshold value.

The touch panel or touch screen is one of the main modern human-machine interfaces. As a position recognition device, it can cleverly combine input and display interfaces, so it has the advantages of saving device space and operating humanity. It has been widely used in All kinds of consumer or industrial electronic products. Examples: personal digital assistant (PDA), palm-sized PC, tablet computer, mobile phone, Information Appliance, Point-Of -Sale, POS) and other devices.

Capacitive touch panels mainly use touch objects such as the human body or stylus when they touch the panel, and use static electricity generated by the touch objects to flow into the ground and generate a weak current to form a coupling capacitor with the touch object and the surface of the touch panel. To achieve the purpose of touch. However, capacitive touch panels are susceptible to interference from environmental electric fields, static electricity, usage conditions, and the like. When the capacitive touch panel is connected to the charger for charging, the grounding of the charger causes the entire circuit board on which the capacitive touch panel is located and the human body to generate a common ground capacitance multiplication effect, which increases the sensing amount, and then makes the capacitive touch panel excessive Sensitive; when the power of the capacitive touch panel is gradually depleted, the sensitivity of the capacitive touch panel will Continue to decrease. The above-mentioned capacitive touch panel is too sensitive or the sensitivity is reduced, which affects the use of the capacitive touch panel.

Furthermore, the state of the user using the touch panel is changing more and more. In order to adapt to the use mode of the user wearing gloves, direct finger operation, using a stylus or other touch objects, the signal detection of the touch panel The signal strength and response waveform of the measurement method to deal with various usage modes will also be different. Therefore, when the signal detection method uses only a single or fixed judgment standard, it is difficult to make a correct judgment, and the response sensitivity of the touch panel is reduced, even Unable to operate smoothly.

In view of the above-mentioned background of the invention, embodiments of the invention provide a signal detection method and system for a touch device with a dynamically adjusted threshold value. Generally speaking, the original default environment under ideal conditions is defined as when the control unit in the signal detection system drives and detects all the sensing nodes on the touch device several times at low and high potentials, and finds that When the signals of all the sensing nodes are in the preset intensity range, it is determined that the touch device is in an ideal condition, and different preset signal intensity ranges are used for low and high potential driving. It can also be said that the original default environment under ideal conditions is that the touch device does not detect any noise when in use, including the user not using the touch device in the charging mode, and the user’s direct finger operation. In addition, no water vapor or any touch of objects other than fingers is detected on the touch device, and objects other than fingers include pointing objects such as palms and stylus pens.

According to the present invention, according to different usage conditions, the threshold value is dynamically adjusted at each detection time point to filter the detected signal and its signal value, and then perform signal processing. Regardless of whether the touch device is being charged, in low power consumption or the user's operating mode (For example, instead of using finger touch, using stylus touch) and its environment, it can effectively improve the sensitivity of the touch device.

In order to achieve one or part or all of the above objects or other objects, embodiments of the present invention provide a signal detection method for a touch device, wherein the touch device includes a plurality of sensor nodes and has a dynamically adjusted upper threshold value And the lower threshold value, which includes: reading the preset first threshold value to set the upper threshold value and the lower threshold value; performing a scanning procedure to obtain a plurality of initial signals of a plurality of sensing nodes, where the initial signals include signal values ; From a plurality of signal values, select a strongest signal value; compare the upper threshold and half of the strongest signal value; when half of the strongest signal value is greater than or equal to the upper threshold, adjust the first threshold to half the strongest signal value ; Carry out a screening process to compare a plurality of signal values with the first threshold value, and define an initial signal greater than or equal to the first threshold value as a screening signal; and, perform a signal processing procedure on the screening signal.

In one embodiment, the upper threshold and the lower threshold are the first threshold plus or minus a fixed amount, or the first threshold multiplied by a fixed ratio.

In one embodiment, when one half of the strongest signal value is less than the upper threshold value, the half of the strongest signal value is compared with the lower threshold value. When half of the strongest signal value is less than the lower threshold value, the adjustment generates a second threshold value that is less than the first threshold value; when half of the strongest signal value is greater than or equal to the lower threshold value, the first threshold value is not adjusted and the above is performed directly Screening procedures. Wherein, when the number of times that the first threshold value is not adjusted reaches a certain number, the adjustment generates a second threshold value smaller than the first threshold value. In one embodiment, the method for generating the second threshold value includes: multiplying the first threshold value by a fixed ratio, or subtracting a certain amount from the first threshold value, until the second threshold value approaches below a preset value Limit. Wherein, the preset lower limit value is a lower threshold value or a half or a quarter of a preset driving voltage value.

In one embodiment, the touch device further includes a preset upper limit value, and the upper limit value is less than or equal to a preset driving voltage value. Among them, the upper threshold or the first threshold is less than the upper limit. This embodiment further includes deleting the initial signal that is greater than the upper limit among the plurality of signal values before selecting the strongest signal value.

In one embodiment, it further includes deleting the initial signal that is less than the first threshold value among the plurality of signal values.

In one embodiment, before selecting the strongest signal value, it further includes: performing a signal compensation procedure according to the relative relationship of each signal value.

In one embodiment, the signal processing procedure includes determining touch position, multi-touch, single-touch or touch position tracking.

In one embodiment, under ideal conditions, all thresholds are adjusted back to the initial preset first threshold.

In order to achieve one or part or all of the above objects or other objects, another embodiment of the present invention provides a signal detection system for a touch device, wherein the touch device includes a plurality of sensor nodes, and the signal detection system includes a Detection unit and a processing unit. The detection unit is used to receive signal information on a plurality of sensing nodes, and has a dynamically adjusted upper threshold and a lower threshold, and the detection unit transmits the information to the processing unit through various interfaces. The detection unit reads a preset first threshold value, and sets the upper and lower threshold values according to the first threshold value; the detection unit performs a scanning procedure to obtain a plurality of initial signals of the plurality of sensor nodes and send them To the processing unit, the initial signal includes the signal value; among the multiple signal values, the processing unit selects a strongest signal value; the processing unit compares the upper threshold value and half of the strongest signal value; when the strongest signal value is greater than or equal to the upper threshold Value, the processing unit adjusts the first threshold to one of the strongest signal values Half; the processing unit performs a screening procedure to compare a plurality of signal values with the first threshold value, and defines an initial signal greater than or equal to the first threshold value as a screening signal; and the processing unit performs a signal processing on the screening signal program.

100‧‧‧Touch Device

120‧‧‧First electrode or driving electrode

130‧‧‧Second electrode or sensing electrode

200‧‧‧Signal Detection System

210‧‧‧Detection Unit

220‧‧‧Processing unit

N‧‧‧sensing node

S100~S800‧‧‧Step

The first figure is a schematic diagram of a touch device and its signal detection system in an embodiment of the invention.

The second and third figures are schematic flowcharts of a signal detection method for a touch device in an embodiment of the present invention.

A person of ordinary skill in the art can understand that the execution order of the steps included in the method provided in the embodiment of the present invention may not necessarily follow the order shown in the embodiment, unless there is a special dependency relationship between the steps. The invention does not limit the execution order between the various steps. In addition, other steps can be inserted between each step without affecting the spirit provided by the present invention. The practical examples derived in this way will also fall into the scope of the present invention.

Please refer to the first figure, which is a schematic diagram of a touch device 100 and its signal detection system 200 according to an embodiment of the present invention. The touch device 100 includes a plurality of first electrodes or driving electrodes 120 and a plurality of second electrodes or sensing electrodes 130 located on a touch area. Between the first electrode 120 and the second electrode 130, there will be a plurality of regions overlapping each other but not in contact with each other, which are defined as the sensing node N in this embodiment. The first electrode 120 and the second electrode 130 are both connected to a detection unit 210 in the signal detection system 200, and the detection unit 210 is used for receiving the signal information measured on the sensing node N. The detection unit 210 can detect the touch The event information is sent to the processing unit 220 and other circuits or modules, such as the main processor of a computer system.

Please refer to the second figure and the third figure at the same time, which is a signal detection method of a touch device in an embodiment of the invention. The detection unit 210 signal-connected to the touch device 100 has a dynamically adjustable upper threshold TH _U (Upper Threshold) and a lower threshold TH _L (Lower Threshold). The signal detection method of the touch device 100 executes the following steps through the above-mentioned signal detection system 200.

Step S100: The detection unit 210 reads a preset first threshold value, and sets the upper threshold value and the lower threshold value according to the first threshold value, and loads the upper threshold value for the signal judgment with the preset first threshold value The value and the lower threshold are in the signal detection system 200. In the embodiment of the present invention, the upper threshold and the lower threshold are set by adding a fixed value and subtracting a fixed value from the first threshold value, or by multiplying the first threshold value by a fixed ratio.

Step S200: the detection unit 210 performs a scanning process to drive the first electrode and sense the change of the capacitance of the second electrode to obtain a plurality of initial signals on the plurality of sensing nodes N. The initial signal of each sensor node is recorded as pt, and its recording function is pt(x,y,S), where x and y represent a position information of the initial signal, and S (signal strength) represents a signal of the initial signal value. In this embodiment, regardless of whether there is a touch object on the touch device for contact, scanning and analysis are performed at any time to perform the signal acquisition process to obtain the initial signals of all the sensor nodes on the comprehensive board for signal analysis and recording.

Step S300: Among the signal values of the plurality of initial signals obtained above, a strongest signal value is selected and recorded as S _MAX . Since each sensing node on the touch area of each touch device has a different sensing strength of its capacitance change, the signal value of the initial signal obtained in the above steps will be different. Therefore, in this embodiment, before performing this step to find the strongest signal value, it further includes: performing a signal compensation procedure according to the relative relationship of each signal value. After that, look for the initial signal with the strongest signal value.

In this embodiment, the touch device further includes a preset upper limit value, and the upper limit value is less than or equal to its preset driving voltage value. The upper threshold or the first threshold is less than the upper limit. Therefore, in this embodiment, before performing the step of selecting the strongest signal value, it further includes: deleting the initial signal that is greater than the upper limit among the plurality of signal values.

Step S400: Compare the upper threshold TH _U with one half of the strongest signal value S _MAX .

Step S500: When half of the strongest signal value is greater than or equal to the upper threshold value: S _MAX /2≧TH _U , adjust the first threshold value in step S100 to half of the strongest signal value S _MAX /2.

Step S600: Perform a screening process to compare the signal values of a plurality of initial signals with the first threshold value adjusted in step S500, and define the initial signal whose signal value is greater than or equal to the first threshold value as a screening signal. That is, a plurality of initial signals pt1 to ptn are sequentially filtered with a new first threshold value, where n represents the number of initial signals.

Step S610: Delete the initial signal that is less than the first threshold value among the plurality of signal values.

Step S700: Following step S600, the filtered signal is subjected to a signal processing procedure. In this step, the initial signal pt that has passed the above screening is used for signal processing procedures, such as signal processing to perform intensity distribution pattern analysis to determine the source of the signal. The signal processing procedures include determining touch position, multi-touch, and single-touch Or touch location tracking.

Finally, after the above steps are completed, before the next measurement cycle, perform the point-finding action to obtain all the initial signals pt1~ptn, repeat steps S200-S400 and make further judgments Follow-up actions.

In this embodiment, the newly generated initial signal is further checked, or the step S400 in the previous cycle is continued, and the upper threshold TH _{U is} compared with one half of the strongest signal value S _MAX .

Please refer to the second and third diagrams at the same time. After preliminary comparison, when half of the strongest signal value is less than the upper threshold value: S _MAX /2<TH _U , then step S410: compare half of the strongest signal value S _MAX /2 And the lower threshold TH _L.

Step S420: When half of the strongest signal value is greater than or equal to the lower threshold value: S _MAX /2≧TH _L , then the first threshold value is not adjusted and the initial signal is directly subjected to a screening process.

Step S430: The above-mentioned screening procedure compares the signal value of the initial signal with the first threshold value, and defines the initial signal whose signal value is greater than or equal to the first threshold value as the screening signal.

Step S440: After repeating the above steps S410-S430, when the number of times that the first threshold value is not adjusted reaches a certain number, the adjustment generates a second threshold value smaller than the first threshold value. In the embodiment of the present invention, the certain number of times that the first threshold value is not adjusted can be directly set by the processing unit to be 3, 5, 7 consecutive times, etc., but the present invention is not limited thereto.

In other words, when the strongest signal value S _MAX in the new initial signal obtained in successive cycles is smaller to a certain amount, the first threshold value is gradually reduced to adjust the second threshold value to be smaller than the first threshold value. Threshold value. The method for generating the second threshold value includes: multiplying the first threshold value by a fixed ratio or a product of less than a percentage, or subtracting a certain amount from the upper threshold value until the second threshold value approaches a preset value Limit. In this embodiment, the method of lowering may be to multiply the first threshold value by 95%, 90%, 75%, 70%, 50%, etc., which is less than the product of the percentage, until it approaches the preset lower limit. ; Or the first threshold value is directly subtracted by a certain amount until approaching the preset lower limit, but the present invention is not limited to this. Even the first threshold value can be processed by exponential logarithmic function, so that the second threshold value approaches the lower limit value. Wherein, the preset lower limit value is the lower threshold value or one half or one quarter of a preset driving voltage value. For example, the lower limit value can be half of the preset driving voltage value 3.3V, that is, 1.65V; or The limit value can be half of the preset driving voltage value of 5V, that is, 2.5V.

Step S450: Following step S410, when one half of the strongest signal value is less than the lower threshold value: S _MAX /2<TH _L , then the adjustment generates a second threshold value smaller than the first threshold value. The method for generating the second threshold value includes: multiplying the first threshold value by a fixed ratio or a product of less than a percentage, for example, multiplying the first threshold value by 95%, 90%, 75%, 70%, 50% Either less than the product of percentage cases; or subtract a certain amount from the first threshold until the second threshold approaches the preset lower limit.

Step S460: Following step S440 or S450, the initial signal whose signal value is greater than or equal to the second threshold value is defined as the screening signal. Finally, return to step S700 to perform a signal processing procedure on the filtered signal. This step will proceed to the next step through the filtered initial signal pt, such as signal processing to analyze the intensity distribution pattern to determine the source of the signal, where the signal processing procedure includes determining the touch position, multi-touch, single-touch or touch Location tracking.

In the embodiment of the present invention, step S700 is continued, and under ideal conditions, step S800 is further included: adjusting all the adjusted first threshold values or generated second threshold values back to the preset first threshold in step S100 Value; to return to the original default environment for the next signal detection method. In the embodiment of the present invention, the original default environment under ideal conditions is defined as that the touch device does not detect any noise when in use, including the user not using the touch device in the charging mode, and the user Direct finger operation, and no water vapor or touch of objects other than fingers is detected on the touch device. Objects other than fingers include palms and stylus Wait to point to the object.

The signal detection method of the present invention enables the touch device to dynamically adjust the threshold value in real time to adapt to various usage modes and signal strengths, and it can also avoid the situation where the touch position shakes or the response is not sensitive when the signal strength changes too much. With different usage modes, the signal detection threshold can be flexibly adjusted at each detection point, regardless of whether the touch device is being charged, in low power consumption or the user's operating environment mode is different. It can effectively improve the sensitivity of the touch device.

S100-S700‧‧‧Step

Claims (16)

A signal detection method for a touch device, wherein the touch device includes a plurality of sensor nodes, and has a dynamically adjusted upper threshold and a lower threshold. The steps include: reading a preset first threshold , And set the upper threshold and the lower threshold according to the first threshold; perform a scanning procedure to obtain a plurality of initial signals of the plurality of sensing nodes, wherein the plurality of initial signals include a plurality of signal values; From the plurality of signal values, select a strongest signal value; compare the upper threshold value and half of the strongest signal value; when half of the strongest signal value is greater than or equal to the upper threshold value, adjust the first threshold value Half of the strongest signal value; performing a screening process to compare the plurality of signal values with the first threshold value, and define the initial signal greater than or equal to the first threshold value as a screening signal; and The signal is screened for a signal processing procedure. For example, in the signal detection method described in item 1 of the scope of patent application, when half of the strongest signal value is less than the upper threshold value, half of the strongest signal value is compared with the lower threshold value. For example, in the signal detection method described in item 2 of the scope of patent application, when half of the strongest signal value is less than the lower threshold value, the adjustment generates a second threshold value less than the first threshold value. For example, in the signal detection method described in item 2 of the scope of patent application, when half of the strongest signal value is greater than or equal to the lower threshold value, the first threshold value is not adjusted and the screening procedure is directly performed. Such as the signal detection method described in item 4 of the scope of patent application, where the first threshold value is not adjusted When the number of times reaches a certain number, the adjustment generates a second threshold value that is less than the first threshold value. For example, in the signal detection method described in item 3 or 5 of the scope of patent application, the method for generating the second threshold value includes: multiplying the first threshold value by a fixed ratio, or subtracting the first threshold value by a certain amount Until the second threshold approaches a preset lower limit. For the signal detection method described in item 6 of the scope of patent application, the preset lower limit is the lower threshold value or one-half or one-fourth of a preset driving voltage value. Such as the signal detection method described in item 1 of the scope of patent application, wherein the upper threshold and the lower threshold are the first threshold plus or minus a fixed value, or the first threshold multiplied by a fixed ratio . For the signal detection method described in claim 1, wherein the touch device further includes a preset upper limit value, and the upper limit value is less than or equal to a preset driving voltage value. Such as the signal detection method described in item 9 of the scope of patent application, wherein the upper threshold value or the first threshold value is less than the upper limit value. For example, the signal detection method described in item 9 of the scope of patent application further includes deleting the initial signal that is greater than the upper limit of the plurality of signal values before selecting the strongest signal value. For example, the signal detection method described in item 1 of the scope of patent application further includes deleting the initial signal that is less than the first threshold value among the plurality of signal values. For the signal detection method described in item 1 of the scope of patent application, before selecting the strongest signal value, it further includes: performing a signal compensation procedure according to the relative relationship of each signal value. Such as the signal detection method described in item 1 or 3 or 5 of the scope of patent application, in which all thresholds are adjusted back to the preset first threshold under ideal conditions. As for the signal detection method described in claim 1, wherein the signal processing procedure includes determining touch position, multi-touch, single-touch or touch position tracking. A signal detection system for a touch device, wherein the touch device includes a plurality of sensing nodes, and the signal detection system includes: a detection unit for receiving signal information on the plurality of sensing nodes, and having A dynamic adjustment of the upper threshold and the lower threshold; and, a processing unit, the detection unit transmits the signal information to the processing unit through various interfaces; wherein the detection unit reads a preset first threshold Value, and set the upper threshold value and the lower threshold value according to the first threshold value; the detection unit performs a scanning procedure to obtain a plurality of initial signals of the plurality of sensing nodes and send them to the processing unit, wherein the The plurality of initial signals include a plurality of signal values; from the plurality of signal values, the processing unit selects a strongest signal value; the processing unit compares the upper threshold value with half of the strongest signal value; when the strongest signal value is half Greater than or equal to the upper threshold value, the processing unit adjusts the first threshold value to half of the strongest signal value; the processing unit performs a screening procedure to compare the plurality of signal values with the first threshold value, and The initial signal greater than or equal to the first threshold is defined as a screening signal; and, the processing unit performs a signal processing procedure on the screening signal.

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