TW201706786A - Method for determining frequency of scanning signal and detecting method - Google Patents

Abstract

A method for determining frequency of scanning signal, applicable for a touch panel, includes the steps below: selecting a plurality of candidate frequency among a preset range of signal frequency, selecting a plurality of touching characteristic point in the touching area of the touch panel, scanning the touch panel with a plurality of candidate signal corresponding to the plurality of candidate frequency.

Description

Scanning signal frequency determining method and detecting method

The invention relates to a scanning signal frequency determining method and a detecting method, in particular to a scanning device frequency determining method and a touch detecting method thereof.

As a convenient input device, the touch panel is widely used in various electronic devices. A projected capacitive, capacitive or resistive touch panel usually emits a scan signal on a scan line, obtains a corresponding received signal from the sense line, and determines whether a point on the touch panel is touched by the received signal.

However, the current method of determining the frequency of the scanned signal is usually determined directly by the designer based on experience. However, the scanning signals of different frequencies may be affected by the degree of circuit noise in the touch panel. How to systematically find the frequency of the good scanning signal to avoid the misjudgment caused by the noise in the touch panel is awaiting solved problem.

In view of the above problems, the present invention provides a method for determining a frequency of a scanning signal and a related touch detection method. In the method for determining the frequency of the scanning signal proposed in an embodiment of the present invention, the frequency of the scanning signal with better anti-noise ability is determined by systematic steps. Therefore, compared with the design method that generally determines the frequency of the scanning signal empirically, the designer of the touch panel can obtain the scanning signal frequency with a lower false alarm rate by applying the method disclosed in the present invention.

The scanning signal frequency determining method disclosed in the present invention is suitable for a touch panel, and the method comprises the following steps: selecting a plurality of candidate frequencies from a preset signal frequency range. Selecting a plurality of touch feature points from the touch area of the touch panel. The touch panel is scanned with a plurality of candidate signals having the aforementioned candidate frequencies. For each candidate signal, a plurality of noise energy values corresponding to the touch feature points are calculated on page 2 for a total of 7 pages (invention description) to obtain a noise feature amount corresponding to each candidate signal. According to the noise standard and the obtained plurality of noise feature quantities, one of the selected signals is selected as the scan signal of the touch panel.

The detection method disclosed in the present invention is applicable to touch detection of a touch panel. The method includes the following steps: scanning a touch panel with a scan signal having a first signal frequency to obtain a plurality of received signals. When at least one of the plurality of energy values of the received signal is greater than the touch threshold, determining whether the energy value distribution of the received signal conforms to the noise distribution. When the energy distribution does not conform to the noise distribution, at least one coordinate signal is generated according to the received signal. When the energy distribution conforms to the noise distribution, the scanning signal correction program is executed, and the step of scanning the touch panel with the scanning signal is returned. The scanning signal correction program includes the following steps: selecting a plurality of candidates to be selected from the preset frequency range frequency. The touch panel is scanned with a plurality of candidate signals having the aforementioned candidate frequencies. For each of the to-be-selected signals, a plurality of noise energy values corresponding to the plurality of touch feature points of the touch panel are respectively calculated to obtain a noise feature amount corresponding to each candidate signal. One of the aforementioned candidate signals is selected as the scan signal according to the noise standard and the obtained plurality of noise feature quantities.

The above description of the present invention and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention.

The detailed features and advantages of the present invention are described in detail below in the embodiments, which are sufficient to enable anyone skilled in the art to understand the technical contents of the present invention and to implement the third page, a total of seven pages (invention), and according to the present invention. The related objects and advantages of the present invention can be readily understood by those skilled in the art from the disclosure. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Please refer to FIG. 1 , which is a schematic diagram of a touch panel and an embedded controller thereof according to an embodiment of the invention. As shown in FIG. 1 , the touch panel 1000 has an embedded controller 1100 , M scanning lines Tx1 T TxM, and N sensing lines Rx1 R RxN. The embedded controller 1100 sequentially sends the scan signals by the scan lines Tx1 to TxM, and senses the received signals with the sense lines Rx1 to RxN.

In an embodiment, when the touch panel 1000 is to determine the frequency of the scan signal, the method for determining the same is referred to FIG. 1 and FIG. 2, wherein FIG. 2 is a scan frequency according to an embodiment of the present invention. Determine the method flow chart. As shown in FIG. 2, the scanning frequency determining method of this embodiment includes the following steps. First, as shown in step S2100, the embedded controller 1100 selects a plurality of candidate frequencies from the preset signal frequency range. For example, the so-called preset signal frequency range is a frequency range centered generally on the frequency of the empirically determined scan signal. Assuming that the general experience determines that the frequency of the scan signal is 100 kHz (kilo-hertz, kHz), the preset signal frequency range can be from 50 kHz to 150 kHz. In the following embodiment, the embedded controller 1100 selects eleven candidate frequencies from 50 kHz to 150 kHz, which are 50 kHz, 60 kHz, 70 kHz, ... 140 kHz and 150 kHz, respectively.

As shown in step S2200, the embedded controller 1100 selects a plurality of touch feature points from the touch areas of the touch panel 1000. In one embodiment, the embedded controller 1100 selects four intersection points of the intersection of the scan line Txi, the scan line Txj, the sensing line Rxx, and the sensing line Rxy as the touch feature points. Where i and j are positive integers less than or equal to M and x and y are positive integers less than or equal to N. i is not equal to j and x is not equal to y.

Then, as shown in step S2300, the embedded controller 1100 scans the touch panel 1000 with a plurality of candidate signals having the aforementioned candidate frequencies. And as shown in step S2400, for each candidate signal, the embedded controller 1100 respectively calculates a plurality of noise energy values corresponding to the fourth page of the plurality of touch feature points, a total of 7 pages (invention description), to obtain each The amount of noise features corresponding to the candidate signals. Specifically, in an embodiment, the embedded controller 1100 scans the scan line Txi and the scan line Txj with at least the candidate signal having the aforementioned candidate frequency, and acquires the received signal from the sensing line Rxx and the sensing line Rxy. For example, the embedded controller 1100 first scans the scan line Txi and the scan line Txj with a candidate signal having a frequency of 50 kHz, and then acquires a received signal from the sense line Rxx and the sense line Rxy. Next, the embedded controller 1100 performs the following operations on the four received signals corresponding to the four touch feature points.

Taking the touch feature point of the scan line Txi and the sense line Rxx as an example, the embedded controller 1100 first performs spectrum analysis on the received signal of the touch feature point to obtain a candidate for the touch feature point and the frequency of 50 kHz. The energy spectrum of the received signal of the signal. Methods of spectrum analysis such as fourier transform, wavelet transform, or other similar methods (such as fast Fourier transform). Next, the embedded controller 1100 removes the energy of the frequency of 50 kHz from the energy spectrum distribution to obtain a noise spectrum corresponding to the candidate signal of the frequency of 50 kHz. Then, according to the noise spectrum distribution, the candidate signal with a frequency of 50 kHz and the noise energy value at the touch feature point are calculated. For example, if the noise spectrum is distributed over the frequency domain, the sum of the energy of all the noises, that is, the aforementioned noise energy value, is obtained. By performing the foregoing processing on the other three touch feature points in this order, a total of four noise energy values are obtained. Then, the noise characteristic corresponding to the candidate signal with a frequency of 50 kHz is calculated by using the four noise energy values. For example, the amount of noise feature can be defined as the difference or ratio of the energy with the smallest energy and the lowest of the four noise energy values, but is not limited thereto. In other embodiments, the embedded controller 1100 first removes the component of the frequency of 50 kHz in the received signal with a filter, and then performs subsequent calculations to obtain the amount of noise features.

In this way, the embedded controller 1100 also calculates the noise feature quantity of the other candidate signals in the foregoing manner, for example, the candidate signal with a frequency of 60 kHz, the frequency of 70 kHz, the fifth page, a total of 7 pages (invention specification) Select the signal... even the candidate signal with a frequency of 150 kHz. Then, as shown in step S2500, the embedded controller 1100 selects one of the candidate signals as the scan signal of the touch panel 1000 according to the aforementioned noise feature quantity and a noise standard. In an embodiment, the so-called noise standard specifies that the embedded controller 1100 selects the smallest candidate signal corresponding to the noise feature quantity as the scan signal. If the noise signal of the candidate signal with a frequency of 90 kHz is calculated according to the foregoing method is smaller than the noise characteristic of the candidate signal of the remaining frequency, the embedded controller 1100 uses the candidate signal with a frequency of 90 kHz as the scanning signal. .

Specifically, after the embedded controller 1100 scans the candidate signal with a frequency of 50 kHz, the frequency value and the noise feature amount are first stored in the memory unit of the embedded controller 1100. Then, the signal is scanned with a candidate signal having a frequency of 60 kHz, and it is judged whether the amount of the noise feature is smaller than the amount of the noise feature stored in the memory unit. If the result of the determination is no, the scanning of the candidate signal with the frequency of 70 kHz is continued, if it is judged As a result, the frequency value and the noise feature quantity in the memory unit are overwritten with the frequency value and the noise feature quantity of the candidate signal of 60 kHz, and the candidate signal of the frequency of 70 kHz is continuously scanned, and the above principle is repeated to select The frequency value and the amount of noise features in the memory unit are overwritten. After the embedded controller 1100 scans and completes the foregoing operation with the candidate signal of frequency 150 kHz, the embedded controller 1100 selects the retained frequency value from the memory unit, and the noise feature quantity is multiple in the preset frequency range. The frequency to be selected has the lowest amount of noise features.

In another embodiment, the noise standard is a noise characteristic threshold, and the embedded controller 1100 selects one of the candidate signals whose noise feature is lower than the noise characteristic threshold as the scan signal. For example, a candidate signal having a noise characteristic threshold of 20 and a noise characteristic of less than 20 has a candidate signal having a frequency of 70 kHz, a candidate signal having a frequency of 110 kHz, and a candidate signal having a frequency of 130 kHz. Then, the embedded controller 1100 selects one of the aforementioned three candidate signals (for example, a candidate signal having a frequency of 110 kHz) as a scan signal.

Therefore, the present invention further discloses a touch detection method using the foregoing scan signal determination method. Please refer to FIG. 1 and FIG. 3 together, wherein FIG. 3 is based on page 6 of the embodiment of the present invention, a total of 7 pages (invention specification) ) The method of detection method. As shown in FIG. 3, the touch detection method disclosed in the present invention has the following steps:

As shown in step S3100, the embedded controller 1100 scans all the scan lines of the touch panel with a scan signal to obtain a plurality of received signals from all the sense lines, and the scan signals have a first signal frequency, for example, 100 kHz. And as shown in step S3200, it is determined whether the energy value of one of the plurality of received signals is greater than a touch threshold. When the result of the determination is no, the process returns to step S3100 to perform the next scan. When the result of the determination is yes, as shown in step S3300, the embedded controller 1100 further determines whether the energy value distribution of the received signal conforms to the noise distribution. If the result of the determination is no, as shown in step S3400, the embedded controller 1100 generates at least one coordinate signal in accordance with the aforementioned received signal. If the result of the determination is YES, the scan signal correction program is executed as shown in step S3500, and then returns to step S3100 to scan with the corrected scan signal. The scanning signal correction program is the scanning signal frequency determining method as shown in FIG. 2. The preset frequency range is a frequency range centered on the first signal frequency, for example, 50 kHz to 150 kHz.

The noise distribution in step S3300, for example, if the touch panel 1000 is a general single touch, the intersection of the scan line and the induction line corresponding to the received signal whose energy value is greater than the touch threshold is not gathered. Together, but scattered into multiple blocks, it is judged that it is not a normal touch result. Or when the intersection point corresponding to the received signal whose energy value is greater than the touch threshold is gathered together, but the total number is greater than a quantity threshold, that is, the area touched by the touch is too large, which may be a misjudgment caused by noise. Or the user's abnormal operation.

If the touch panel 1000 can support multi-touch, the so-called noise distribution may be that the touched area corresponding to the touched area is too large, or the received value corresponding to the received value of the touch threshold is corresponding to the same scan. All intersections (or most intersections) of the line (or induction line). In other words, a touch pattern (pa t t e rn) that is not possible for a general user's touch operation can be used as a possible noise distribution.

In addition, when the scan signal correction program is executed, the touch feature to be selected is 7 pages, a total of 7 pages (invention specification) point. In one embodiment, the intersection point corresponding to the energy value greater than the touch threshold may be It is really touched by the user, so the touch feature points must be selected from other intersections where the energy value is not greater than the touch threshold. In another embodiment, for example, when the energy value is greater than the touch threshold corresponding to the plurality of intersection points corresponding to the same scan line, since the error should be caused by noise, at least one touch feature point must be determined by the energy value. A plurality of intersection points corresponding to the touch threshold are selected.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1000‧‧‧Touch panel
1100‧‧‧Inline controller
Tx1~TxM‧‧‧ scan line
Rx1~RxN‧‧‧Induction line

1 is a schematic diagram of a touch panel and an embedded controller thereof according to an embodiment of the invention. 2 is a flow chart of a method for determining a scanning frequency according to an embodiment of the present invention. 3 is a flow chart of a detection method according to an embodiment of the invention.

Claims (19)

A method for determining a frequency of a scanning signal is suitable for a touch panel, the method comprising: selecting a plurality of selected frequencies from a predetermined signal frequency range; and selecting a plurality of touch features from the touch area of the touch panel a plurality of candidate signals having the to-be-selected frequencies are scanned; and for each of the to-be-selected signals, a plurality of noise energy values corresponding to the touch feature points are respectively calculated to obtain a noise characteristic quantity corresponding to the candidate signal; and selecting one of the candidate signals as a scan signal of the touch panel according to the noise feature quantity and a noise standard. The method of claim 1, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. The step of subtracting the minimum noise energy value among the noise energy values is the maximum noise energy value of the noise energy values to obtain the noise feature quantity. The method of claim 1, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. The step of dividing the noise energy value of the plurality of noise energy values by the minimum noise energy value among the noise energy values to obtain the noise feature quantity. The method of claim 1, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. In the step, each touch feature point includes: performing spectrum analysis on a received signal associated with the touch feature point and the candidate signal to obtain an energy spectrum distribution; and removing corresponding correspondence from the energy spectrum distribution The energy of the candidate signal is used to obtain a noise spectrum distribution; and the noise energy value for the candidate signal and the touch feature point is calculated according to the noise spectrum distribution. The method of claim 4, wherein performing spectrum analysis on the received signal performs a wavelet transform or a fast four-ier transform (FFT) on the received signal. The method of claim 1, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. In the step, each of the touch feature points includes: filtering a received signal associated with the touch feature point and the candidate signal to filter the candidate signal; and performing spectrum on the filtered received signal The analysis is performed to obtain an energy spectrum distribution; and the noise energy value for the candidate signal and the touch feature point is calculated according to the energy spectrum distribution. The method of claim 1, wherein in the step of selecting one of the candidate signals as the scan signal of the touch panel according to the noise feature quantity and the noise standard, selecting the The candidate signal corresponding to the amount of the noise feature having the smallest amount of noise features is used as the scan signal. The method of claim 1, wherein the noise standard is a noise characteristic threshold, and one of the candidate signals is selected as the touch panel according to the noise feature quantity and the noise standard. The step of scanning the signal includes selecting one of the at least one candidate signal whose corresponding feature quantity of the noise is lower than the threshold of the noise characteristic as the scan signal. The method of claim 1, wherein the touch feature points are arrayed in a touch area of the touch panel. A method for detecting a touch panel, the method comprising: scanning the touch panel with a scan signal to obtain a plurality of received signals, the scan signal having a first signal frequency; When at least one of the plurality of energy values is greater than a touch threshold, determining whether an energy value distribution of the received signals conforms to a noise distribution; and when the energy value distribution does not conform to the noise distribution, according to the received signals Generating at least one calibration signal; and when the energy distribution conforms to the noise distribution, performing a scan signal correction procedure and returning to the step of scanning the touch panel with the scan signal, the scan signal correction program includes: Selecting a plurality of to-be-selected frequencies in a predetermined frequency range; scanning the touch panel with a plurality of candidate signals having the to-be-selected frequencies; and calculating, for each of the to-be-selected signals, corresponding to the touch panel Multiple noise energy values of the plurality of touch feature points to obtain a noise feature quantity corresponding to the candidate signal; and selecting according to the noise feature quantity and a noise standard Wherein one of these candidate signal as the scanning signal. The method of claim 10, wherein the predetermined frequency range is centered at the first signal frequency. The method of claim 10, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. The step of subtracting the minimum noise energy value among the noise energy values is the maximum noise energy value of the noise energy values to obtain the noise feature quantity. The method of claim 10, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. The step of dividing the noise energy value of the plurality of noise energy values by the minimum noise energy value among the noise energy values to obtain the noise feature quantity. The method of claim 10, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. In the step, for each of the touch feature points, the method includes: performing spectrum analysis on the received signal associated with the touch feature point and the candidate signal to obtain an energy spectrum distribution; and removing corresponding correspondence from the energy spectrum distribution The energy of the candidate signal is used to obtain a noise spectrum distribution; and the noise energy value for the candidate signal and the touch feature point is calculated according to the noise spectrum distribution. The method of claim 14, wherein performing spectrum analysis on the received signal performs a wavelet transform or a fast four-ier transform (FFT) on the received signal. The method of claim 10, wherein the noise energy values corresponding to the touch feature points are respectively calculated for each of the candidate signals to obtain the noise feature amount corresponding to the candidate signal. In the step, each of the touch feature points includes: filtering the received signal associated with the touch feature point and the candidate signal to filter the candidate signal; and performing spectrum on the filtered received signal The analysis is performed to obtain an energy spectrum distribution; and the noise energy value for the candidate signal and the touch feature point is calculated according to the energy spectrum distribution. The method of claim 10, wherein in the step of selecting one of the candidate signals as the scan signal of the touch panel according to the noise feature quantity and the noise standard, selecting the The candidate signal corresponding to the amount of the noise feature having the smallest amount of noise features is used as the scan signal. The method of claim 10, wherein the noise standard is a noise characteristic threshold, and one of the candidate signals is selected as the touch panel according to the noise feature quantity and the noise standard. The step of scanning the signal includes selecting one of the at least one candidate signal whose corresponding feature quantity of the noise is lower than the threshold of the noise characteristic as the scan signal. The method of claim 10, wherein the touch feature points are arrayed in a touch area of the touch panel.