CN102904562A - Multiple sampling frequency circuit and method - Google Patents

Abstract

The invention provides a multi-sampling frequency circuit and a method, which are suitable for a touch device. The transmitter is used for transmitting a detection signal to the touch device according to the working sampling frequency. The receiver is used for receiving a position signal from the touch device according to the working sampling frequency. The clock pulse generators are used for generating a plurality of sampling frequencies. The switch selects one of the clock pulse generators as the working clock pulse generator according to the switching signal, and outputs the working sampling frequency of the working clock pulse generator to the transmitter and the receiver. The invention utilizes a plurality of sampling frequencies to improve the probability of successful reading and increase the smoothness of the touch device.

Description

Multiple sampling frequency circuit and method

technical field

The invention relates to a multiple sampling frequency circuit, in particular to a multiple sampling frequency circuit suitable for a touch device.

Background technique

In a traditional touch panel design, a control circuit reads signals from a touch sensor according to a sampling rate. When various sources of interference occur (for example: cell phone signal, 60Hz voltage cycle), the control circuit will adjust the sampling frequency to avoid reading errors.

FIG. 1 is a diagram showing the process of adjusting a sampling frequency by a control circuit of a known touch panel. At the beginning, the sampling frequency is the frequency point f1 (the frequency range in FIG. 1 represents that the frequency point f1 can also be a Gaussian distribution frequency range centered on the frequency point f1). When the control circuit finds that the signal is disturbed, it adjusts the sampling frequency to the frequency point f2. If the signal is still disturbed, then adjust the sampling frequency to frequency point f3, and so on.

However, during the process of adjusting the sampling frequency, the control circuit cannot read any signal from the touch sensor, which will lead to an unsmooth user experience.

Contents of the invention

In order to solve the above problems, the present invention provides a multiple sampling frequency circuit, which utilizes multiple sampling frequencies to increase the probability of successful reading and increase the smoothness of use of the touch device.

The present invention provides a multiple sampling frequency circuit suitable for a touch device, comprising: a transmitter for transmitting a detection signal to the above touch device according to an operating sampling frequency; a receiver for sampling according to the above operation The frequency receives a position signal from the touch device; a plurality of clock pulse generators are used to generate multiple sampling frequencies; and a switcher selects one of the above-mentioned clock pulse generators as a working clock pulse according to a switching signal generator, and output the above-mentioned working sampling frequency of the above-mentioned working clock pulse generator to the above-mentioned transmitter and the above-mentioned receiver.

In addition, the present invention provides a method for multiple sampling frequencies, which is suitable for a touch device, including: generating multiple sampling frequencies; and selecting one of the sampling frequencies as a working sampling frequency according to a switching signal, and outputting the working sampling frequency Frequency to a transmitter and a receiver, wherein the transmitter is used to transmit a detection signal to the touch device according to the working sampling frequency, and the receiver is used to receive a position signal from the touch device according to the working sampling frequency .

The present invention utilizes multiple sampling frequencies to increase the probability of successful reading and increase the smoothness of use of the touch device.

Description of drawings

FIG. 1 is a process diagram showing a control circuit of a known touch panel for adjusting a sampling frequency;

FIG. 2 is a schematic diagram showing a multiple sampling frequency circuit according to an embodiment of the present invention;

3A is a schematic diagram showing a multiple sampling frequency circuit according to another embodiment of the present invention;

3B is a schematic diagram showing a detection period of a multiple sampling frequency circuit according to another embodiment of the present invention;

FIG. 4 is a flowchart showing a method for multiple sampling frequencies according to an embodiment of the present invention;

FIG. 5 is a flowchart showing a method for multiple sampling frequencies according to another embodiment of the present invention.

Wherein, the reference signs are explained as follows:

200, 300 ~ multiple sampling frequency circuit;

202～touch device;

204～transmitter;

206～receiver;

208-1, 208-2, ..., 208-N～clock pulse generator;

210～switcher;

212～microcontroller;

400, 500～flow chart;

A1～detection signal;

A2～position signal;

CLK1, CLK2, ..., CLKN～sampling frequency;

CLKO～working sampling frequency;

f1, f2, f3～frequency points;

SF～frequency hopping signal;

SR ~ return signal;

SS ~ switching signal;

T1, T2, T3, T4, T5, T6, T7, T8～ detection cycle;

TX ~ adjust the time.

Detailed ways

FIG. 2 is a schematic diagram showing a multiple sampling frequency circuit 200 according to an embodiment of the invention. As shown in FIG. 2, the multiple sampling frequency circuit 200 can be applied to a touch device 202, and includes: a transmitter 204, a receiver 206, a plurality of clock pulse generators 208-1, 208-2, . . . , 208-N( N is a positive integer greater than or equal to 2), the switch 210 , and the microcontroller 212 . The touch device 202 may include a touch panel, a touch sensor, and the like.

The transmitter 204 can transmit the detection signal A1 to the touch device 202 according to the working sampling frequency CLKO. The receiver 206 can receive the position signal A2 from the touch device 202 according to the working sampling frequency CLKO, so as to obtain the user's touch information (eg, touch position, pressure). A plurality of clock pulse generators 208-1, 208-2, ..., 208-N can be used to generate multiple sampling frequencies CLK1, CLK2, ..., CLKN, for example: the clock pulse generator 208-1 generates sampling frequencies CLK1, ..., The clock pulse generator 208-N generates sampling frequencies CLKN, wherein the sampling frequencies CLK1, CLK2, . . . , CLKN are different frequencies. The clock pulse generator may be a voltage controlled oscillator (voltage control oscillator, VCO). The switcher 210 can select one of the plurality of clock pulse generators 208-1, 208-2, ..., 208-N as the working clock pulse generator according to the switching signal SS, and output the working sampling frequency CLKO of the working clock pulse generator to Transmitter 204 and receiver 206 . For example, if the switching signal SS indicates to select the clock generator 208 - 1 as the working clock generator, the working sampling frequency CLKO is the sampling frequency CLK1 .

Microcontroller 212 may be a stand-alone controller or part of a central processing unit (CPU). The microcontroller 212 can generate different switching signals SS according to user input, for example: generating the switching signal SS to make the switcher 210 select the clock pulse generators 208-1 and 208-2 respectively in sequence in different detection periods (frames). , ..., 208-N are used as the working clock pulse generator, then the working sampling frequency CLKO will be switched to the sampling frequency CLK1, CLK2, ..., CLKN in sequence. The present invention selects different working sampling frequencies CLKO in different detection periods, which can reduce the probability of a single frequency band being interfered, and reduce the negative impact caused by adjusting the working sampling frequency CLKO. This advantage will be described in detail in the following embodiments.

In addition, the microcontroller 212 can receive the report signal SR from the receiver 206, and decide whether to transmit the frequency hopping signal SF to the working clock pulse generator according to the report signal SR, for example: if the report signal SR indicates that the received position signal A2 is interfered (for example: the position signal A2 is an incorrect voltage level, or the position signal A2 indicates that the number of touch positions exceeds the upper limit), the microcontroller 212 transmits the frequency hopping signal SF to the selected working clock pulse generator at this time . In the process of adjusting the frequency of the current working clock pulse generator, the switcher 210 can also select another unused clock pulse generator to continue working as a new working clock pulse generator, so as to reduce the frequency adjustment process. impact on the entire system. The frequency hopping signal SF can be transmitted to the working clock pulse generator alone, and can also be transmitted to multiple clock pulse generators 208-1, 208-2, ..., 208-N at the same time, but only the working clock pulse generator selected at this time This signal can be interpreted. When the selected working clock generator receives the frequency hopping signal SF, the working clock generator converts the working sampling frequency CLKO from a first frequency to a second frequency, wherein the first frequency and the second frequency are different. If the second frequency is still disturbed, the working clock pulse generator can also switch the working sampling frequency CLKO to different third and fourth frequencies, and so on.

FIG. 3A is a schematic diagram showing a multiple sampling rate circuit 300 according to another embodiment of the present invention. FIG. 3B is a schematic diagram showing a detection cycle of the multiple sampling frequency circuit 300 according to another embodiment of the present invention. Hereinafter, the present invention will be described in detail by taking the example where N is equal to 2 in FIG. 3A and FIG. 3B .

The multiple sampling frequency circuit 300 only includes two clock pulse generators 208-1, 208-2, and the microcontroller 212 generates a control signal SS, so that the switcher 210 selects the clock pulse generators 208-1, 208-2 in turn as the working clock pulse generator.

As shown in FIG. 3B , the multiple sampling frequency circuit 300 alternately selects the sampling frequencies CLK1 and CLK2 as the working sampling frequency CLKO in different detection periods T1 , T2 , . . . , T8 in chronological order. In the odd detection period (odd frame) T1, T3, T5, T7, the working sampling frequency CLKO is the sampling frequency CLK1; and in the even detection period (even frame) T2, T4, T6, T8, the working sampling frequency CLKO is the sampling frequency Frequency CLK2. The detection periods T1, T2, . It is worth noting that the method of selecting the sampling frequency in turn is not limited thereto. In other embodiments of the present invention, the multiple sampling frequency circuit 300 may also select the sampling frequency CLK1 as the working sampling frequency in the detection periods T1, T2, T5, and T6. CLKO; and the sampling frequency CLK2 is selected as the working sampling frequency CLKO in the detection periods T3, T4, T7, and T8.

For example, in the detection period T1, the transmitter 204 transmits the detection signal A1 to the touch device 202 according to the sampling frequency CLK1, and the receiver 206 also receives the position signal A2 from the touch device 202 according to the sampling frequency CLK1. If the receiver 206 finds that the position signal A1 is disturbed, it transmits the report signal SR to make the microcontroller 212 transmit the frequency hopping signal SF to the working clock generator at this time, that is, the clock generator 208 - 1 . The clock pulse generator 208-1 starts to adjust the sampling frequency CLK1 from the first frequency to the second frequency. The adjustment process takes an adjustment time TX, during which the clock generator 208-1 cannot generate the correct sampling frequency. As shown in FIG. 3B , the clock pulse generator 208-1 does not successfully adjust the sampling frequency CLK1 until the detection period T6. Therefore, in the detection periods T3 and T5, the multiple sampling frequency circuit 300 will not be able to obtain the user frequency based on the sampling frequency CLK1. touch information. However, the multiple sampling frequency circuit 300 can still obtain the user's touch information according to the sampling frequency CLK2 in the detection periods T2 and T4, which reduces the negative impact during the adjustment time TX.

Since the chance of multiple sampling frequencies being interfered at the same time is much lower than that of a single sampling frequency, the multiple sampling frequency circuit provided by the present invention allows users to use the touch device more smoothly.

FIG. 4 is a flow chart 400 showing a method for multiple sampling frequencies according to an embodiment of the present invention, the method for multiple sampling frequencies is applicable to a touch device. As shown in FIG. 4, firstly, in step S402, a plurality of sampling frequencies are generated. Next, in step S404, according to the switching signal, select one of the plurality of sampling frequencies as the working sampling frequency, and output the working sampling frequency to the transmitter and the receiver, wherein the transmitter is used to transmit the detection signal to the touch device according to the working sampling frequency, The receiver is used for receiving the position signal from the touch device according to the working sampling frequency. On the other hand, a plurality of sampling frequencies may be respectively selected as working sampling frequencies in sequence in different detection periods. In step S406, receive a report signal from the receiver, and determine whether the report signal indicates that the position signal is interfered? If there is interference, in step S408, the working sampling frequency is converted from the first frequency to the second frequency; if there is no interference, in step S410, the working sampling frequency is maintained at the first frequency, and the process ends.

FIG. 5 is a flow chart 500 showing a method for multiple sampling rates according to another embodiment of the present invention, which is applicable to a touch device. As shown in FIG. 5, firstly, in step S510, a plurality of sampling frequencies are generated. Next, in step S520, according to the switching signal, one of the plurality of sampling frequencies is selected as the working sampling frequency, and the working sampling frequency is output to the transmitter and the receiver, and the process ends. The transmitter is used to transmit the detection signal to the touch device according to the working sampling frequency, and the receiver is used to receive the position signal from the touch device according to the working sampling frequency.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined by the appended claims.

Claims (9)

1. A multiple sampling frequency circuit, suitable for a touch device, comprising: a transmitter for transmitting a detection signal to the above-mentioned touch device according to a working sampling frequency; a receiver for receiving a position signal from the touch device according to the working sampling frequency; a plurality of clock pulse generators for generating a plurality of sampling frequencies; and A switcher, coupled to the plurality of clock pulse generators, is used to select one of the plurality of clock pulse generators as a working clock pulse generator according to a switching signal, and output the above-mentioned working clock pulse generator The above-mentioned working sampling frequency to the above-mentioned transmitter and the above-mentioned receiver. 2. The multiple sampling frequency circuit as claimed in claim 1, further comprising: A microcontroller, used to generate the switch signal, and receive a return signal from the receiver, to determine whether to transmit a frequency hopping signal to the above-mentioned working clock pulse generator according to the report signal, wherein if the report signal indicates the above-mentioned When the position signal is disturbed, the microcontroller transmits the frequency hopping signal to the working clock pulse generator. 3. The multiple sampling frequency circuit as claimed in claim 2, wherein the microcontroller is also used to generate the switching signal. 4. The multiple sampling frequency circuit as claimed in claim 2, wherein if the above-mentioned working clock pulse generator receives the above-mentioned frequency hopping signal, then the above-mentioned working clock pulse generator converts the above-mentioned working sampling frequency from a first frequency to a first frequency Two frequencies, wherein the first frequency and the second frequency are different. 5. The multiple sampling frequency circuit as claimed in claim 1, wherein the switcher selects the clock pulse generators as the working clock pulse generators in sequence according to the switching signal. 6. A method for multiple sampling frequencies, applicable to a touch device, comprising: generating multiple sampling frequencies; and Selecting one of the sampling frequencies as a working sampling frequency according to a switching signal, and outputting the working sampling frequency to a transmitter and a receiver; The transmitter is used to transmit a detection signal to the touch device according to the working sampling frequency, and the receiver is used to receive a position signal from the touch device according to the working sampling frequency. 7. The multiple sampling frequency method as claimed in claim 6, further comprising: receiving a feedback signal from the receiver, and determining whether to convert the working sampling frequency from a first frequency to a second frequency according to the feedback signal, wherein the first frequency and the second frequency are different. 8. The multiple sampling frequency method as claimed in claim 6, wherein if the report signal indicates that the position signal is interfered, it is decided to convert the working sampling frequency from the first frequency to the second frequency. 9. The method with multiple sampling frequencies as claimed in claim 6, wherein the sampling frequencies are sequentially selected as the working sampling frequencies respectively.

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