TWI480791B - Touch device and driving method thereof - Google Patents

Description

Touch device and driving method thereof

The present invention relates to a touch device and a touch panel driving method thereof, and more particularly to a touch device and a touch panel driving method thereof, which can improve the positional misjudgment caused by voltage noise.

With the rapid development of technology, most electronic products, such as notebook computers, mobile phones or portable multimedia players, often have touch panels as a new generation input interface. In general, the touch panel is roughly classified into a resistive touch panel, a capacitive touch panel, an optical touch panel, an acoustic wave touch panel, and an electromagnetic touch panel according to different sensing methods. Capacitive touch panels have been widely used in electronic products because of their fast response time, high reliability, and high durability.

The operation of the capacitive touch panel is to use a finger or a conductive material to approach or touch the touch panel to change the capacitance value on the touch panel. When a change in capacitance value is detected, the position that is approached or touched by the finger or the conductive object can be determined.

Due to limitations in power supply capacity, today's electronic products, such as mobile phones, tablets, etc., often need to be used while charging. However, when the electronic product is connected to the charger, the noise generated by the charger converting the AC voltage to the DC voltage will affect the detection of the capacitance value through the ground terminal of the chip circuit in the electronic product. In addition, there is a case where the touch point judgment error or the touch sensitivity is lowered to lower the use quality.

FIG. 1 is a schematic diagram of a touch of a conventional capacitive touch panel. As shown in FIG. 1 , the touch method of the conventional capacitive touch panel sequentially drives the scan lines (the scan lines TX1 to TX5 are sequentially driven as shown in FIG. 1 ), and is driven during each scan line. Receiving a touch sensing signal through the sensing line (as shown in FIG. 1 through the sensing lines RX1 RX8), the touch sensing signal is used to know the amount of change in the capacitance value of the capacitive touch panel. Then, the touch position is determined. As shown in FIG. 1, when the user touches the positions of the scan lines TX4, TX5 and the sensing lines RX3 R RX5, the amount of change in the capacitance value corresponding to the position will be different from the other positions, so that the user's touch can be known. position.

Although the touch method of the conventional capacitive touch panel can effectively determine the touch position of the user, it does not prevent the misjudgment of the touch position caused by the noise of the charger. As shown in FIG. 1 , it is assumed that the AC voltage noise generated by the transformer is generated in the interval of the scan lines TX1 to TX3, thereby affecting the capacitance value of the panel capacitor on the scan lines TX1 to TX3, so that the sensing capacitance value is sensed. The device mistakenly believes that the capacitive touch panel is touched. As shown in FIG. 1, if AC voltage noise appears on the sensing lines RX3 R RX5, the sensor will consider that there is a touch between the scan lines TX1~TX3 and the sensing lines RX3~RX5.

The invention provides a touch device and a driving side thereof The method can effectively improve the misjudgment of the touch position caused by voltage noise.

The invention provides a driving method of a touch panel, wherein the touch panel comprises a plurality of scanning lines and a plurality of sensing lines, and the driving method of the touch panel comprises the following steps. The scan lines are randomly driven during a sensing period, wherein each of the scan lines is driven once during the sensing period. The self-sensing line receives a plurality of touch sensing signals. The touch position of the touch panel is determined according to the touch sensing signal.

In an embodiment of the invention, the step of determining the touch position of the touch panel according to the touch sensing signal further includes the following steps. Counting according to the touch sensing signal to obtain a plurality of count values. Spatially filter the count value. The touch position of the touch panel is determined according to the result of the spatial filtering.

The invention also provides a touch device, which comprises a touch panel, a driving module, a sensing unit and a processing unit. The touch panel includes a plurality of scan lines and a plurality of sensing lines. The driving module is coupled to the scan line to randomly drive the scan lines during a sensing period, wherein each scan line is driven once during the sensing period. The sensing unit is coupled to the sensing line, and receives a plurality of touch sensing signals from the sensing line, and performs counting according to the touch sensing signals to obtain a plurality of counting values. The processing unit is coupled to the driving module and the sensing unit, and determines the touch position of the touch panel according to the count value.

In an embodiment of the invention, the processing unit further spatially filters the count value, and determines the touch position of the touch panel according to the result of the spatial filtering.

In an embodiment of the invention, the driving module includes a random number generator and a driving unit. The random number generator is used to generate random numbers, The moving unit is coupled to the random number generator, the scan line and the processing unit, and drives the scan line randomly according to the random number.

In an embodiment of the invention, the sensing unit includes an integrator, an analog digital converter, and a counter. The integrator is coupled to the sensing line, and respectively integrates the touch sensing signals to obtain a plurality of touch sensing voltages. The analog digital converter is coupled to the integrator to convert the touch sensing voltage into a plurality of digital signals. The counter is coupled to the analog digital converter and the processing unit to generate a count value according to the digital signal.

Based on the above, the present invention drives the scan lines of the touch panel in a random manner to improve the misjudgment of the touch position caused by the voltage noise.

The above described features and advantages of the present invention will be more apparent from the following description.

FIG. 2 is a schematic diagram of a touch device according to an embodiment of the invention. Referring to FIG. 2 , the touch device 200 includes a touch panel 202 , a driving module 204 , a sensing unit 206 , and a processing unit 208 . The touch panel 202 includes a plurality of scan lines TX and a plurality of sensing lines RX, wherein the plurality of scan lines TX are coupled to the driving module 204, and the plurality of sensing lines RX are coupled to the sensing unit 206. In addition, the driving module 204 and the sensing unit 206 are further coupled to the processing unit 208 .

When the touch device 200 performs touch detection, the driving module 204 drives the plurality of scan lines TX on the touch panel 202 during different sensing periods, wherein each scan line TX is in each sensing period. Will be driven one The drive module 204 drives the scan line TX in each sensing period in a random manner.

Further, the driving module 204 can include a driving unit 210 and a random number generator 212. The random number generator 212 is coupled to the driving unit 210, and the driving unit 210 is coupled to the plurality of scanning lines TX and the processing unit 208. The random number generator 212 is configured to generate a hash value such that the driving unit 210 drives the plurality of scan lines TX randomly and informs the processing unit 208 of the order in which the scan lines TX are driven.

The sensing unit 206 receives the touch sensing signals from the plurality of sensing lines RX, and counts according to the received touch sensing signals to obtain a plurality of counting values. Further, the sensing unit 206 can include an integrator 214, an analog digital converter 216, and a counter 218. The integrator 214 is coupled to the sensing line RX, and the analog digital converter 216 is coupled to the integrator 214 and the counter 218 and the processing unit 208. The integrator 214 is configured to respectively integrate the touch sensing signals received by the sensing line RX to obtain a plurality of touch sensing voltages. The analog digital converter 216 converts the plurality of touch sensing voltages into a plurality of digital signals. The counter 218 generates the plurality of count values based on the plurality of digital signals.

The processing unit 208 determines the touch position of the touch panel 202 according to the count value output by the sensing unit 206. For example, the processing unit 208 can spatially filter the received count value to further reduce interference of voltage noise, thereby The filtered result correctly determines the touch position.

Thus, by randomly driving the scan line TX, voltage noise can be dispersed to non-adjacent scan lines, thereby reducing the influence of voltage noise. image 3 A touch diagram of a touch panel according to an embodiment of the invention is shown. Referring to FIG. 3, the range affected by the voltage noise can be effectively dispersed by randomly driving the scan line TX. The driving sequence of the scan line TX shown in FIG. 3 is TX1, TX3, TX5, TX2, and TX4, which can distribute voltage noise to the scan lines TX1, TX3, and TX5 to reduce the range affected by the voltage noise. .

In addition, the count value corresponding to the voltage noise can also be reduced by randomly driving the scan line TX. FIG. 4A is a schematic diagram showing count values obtained by a conventional scanning line driving method of a touch panel. FIG. 4B is a schematic diagram showing the count value obtained by the scan line driving method of the touch panel according to the embodiment of the present invention.

As can be seen from FIG. 4A and FIG. 4B, after the voltage noise is detected by randomly driving the scan line TX, the count value corresponding to the voltage noise distributed on the different scan lines TX becomes smaller. That is, the signal strength of the voltage noise is weakened. After the smaller count value is spatially filtered by the processing unit 208, the count value corresponding to the voltage noise can be filtered out to avoid the occurrence of misjudgment of the touch position.

FIG. 5 is a schematic flow chart of a driving method of a touch panel according to an embodiment of the invention. Referring to FIG. 5 , the manner of driving the touch panel 202 is summarized. The driving method of the touch panel may include the following steps. First, the scan lines are randomly driven during the sensing period (step S502), wherein each of the scan lines is driven once during the sensing period. Next, the plurality of touch sensing signals are received from the sensing line (step S504). Finally, the touch position of the touch panel is determined according to the touch sensing signal (step S506). In detail, step S506 may further include: counting according to the touch sensing signal to obtain a plurality of count values (steps) S506A), spatially filtering the count value (step S506B) and determining the touch position of the touch panel according to the result of the spatial filtering (step S506C).

In summary, the present invention can disperse voltage noise to non-adjacent scan lines by randomly driving the scan lines, thereby reducing the signal strength of the voltage noise and filtering the voltage noise through spatial filtering. The count value is used to improve the misjudgment of the touch position caused by voltage noise.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

200‧‧‧ touch device

202‧‧‧Touch panel

204‧‧‧Drive Module

206‧‧‧Sensor unit

208‧‧‧Processing unit

210‧‧‧Drive unit

212‧‧‧ random number generator

214‧‧‧ integrator

216‧‧‧ analog digital converter

218‧‧‧ counter

TX1~TX12‧‧‧ scan line

RX1~RX23‧‧‧Sensing line

TX‧‧‧ scan line

RX‧‧‧Sensing line

S502~S506C‧‧‧Touch panel driving method steps

FIG. 1 is a schematic diagram of a touch of a conventional capacitive touch panel.

FIG. 2 is a schematic diagram of a touch device according to an embodiment of the invention.

FIG. 3 is a schematic diagram of touch control of a touch panel according to an embodiment of the invention.

FIG. 4A is a schematic diagram showing count values obtained by a conventional scanning line driving method of a touch panel.

FIG. 4B is a schematic diagram showing the count value obtained by the scan line driving method of the touch panel according to the embodiment of the present invention.

FIG. 5 is a schematic flow chart of a driving method of a touch panel according to an embodiment of the invention.

S502~S506C‧‧‧Touch panel driving method steps

Claims (6)

A driving method of a touch panel, wherein the touch panel includes a plurality of scan lines and a plurality of sensing lines, the driving method includes: randomly driving the scan lines during a sensing period, wherein each of the scan lines is Each of the sensing periods is driven once; receiving a plurality of touch sensing signals from the sensing lines; and determining a touch position of the touch panel according to the touch sensing signals. The method for driving the touch panel according to the first aspect of the invention, wherein the step of determining the touch position of the touch panel according to the touch sensing signals further comprises: counting according to the touch sensing signals Obtaining a plurality of count values; spatially filtering the count values; and determining a touch position of the touch panel according to a result of spatial filtering. A touch device includes: a touch panel including a plurality of scan lines and a plurality of sensing lines; and a driving module coupled to the scan lines to randomly drive the scan lines during a sensing period, wherein Each of the scan lines is driven once during the sensing period; a sensing unit is coupled to the sensing lines, and receives a plurality of touch sensing signals from the sensing lines, and according to the touch sensing signals Counting to obtain a plurality of count values; and a processing unit coupled to the driving module and the sensing unit to determine a touch position of the touch panel according to the count values. The touch device of claim 3, wherein the touch device The processing unit further spatially filters the count values, and determines the touch position of the touch panel according to the result of the spatial filtering. The touch device of claim 3, wherein the driving module comprises: a random number generator to generate a random number; and a driving unit coupled to the random number generator, the scan lines and the The processing unit randomly drives the scan lines according to the random value. The touch device of claim 3, wherein the sensing unit comprises: an integrator coupled to the sensing lines, respectively integrating the touch sensing signals to obtain a plurality of touches Sensing voltage; an analog-to-digital converter coupled to the integrator to convert the touch sensing voltages into a plurality of digital signals; and a counter coupled to the analog digital converter and the processing unit, according to the The digital signal produces the count values.