TW201316229A - Capacitive touch display apparatus - Google Patents

Abstract

A capacitive touch display apparatus includes a capacitive touch panel and a capacitive touch sensor including driving lines, sensing lines, and a sensing circuit. At a time, the adjacent first driving line and second driving line are used to input a first driving voltage and a second driving voltage having different phases and voltages. The first sensing line overlaps first driving line to form a first node instead of overlapping second driving line. The second sensing line overlaps second driving line to form a second node instead of overlapping first driving line. A first mutual capacitance and a second mutual capacitance are coupled at the first node and second node, and a first sensing voltage and a second sensing voltage are coupled and outputted by the first sensing line and second sensing line. The sensing circuit subtracts second sensing voltage from first sensing voltage to obtain a sensing voltage difference.

Description

Capacitive touch display device

The present invention relates to a liquid crystal display; in particular, the present invention relates to a capacitive touch display device that uses a staggered electrode arrangement to sense a sensed voltage sensed by an adjacent sense line at the same time. Different drive lines that provide different drive voltages can be used to increase their Signal-Noise Ratio (SNR).

With the rapid development of technology, thin film transistor liquid crystal display (TFT LCD) has gradually replaced traditional displays, and has been widely used in various electronic products such as televisions, flat panel displays, mobile phones, tablet computers and projectors. For a thin film transistor liquid crystal display with touch function, the touch sensor is one of its important modules, and its performance directly affects the overall performance of the liquid crystal display.

As shown in FIG. 1 , a capacitive touch sensor for sensing a touch point formed on a capacitive touch panel includes a driving electrode DE and a sensing electrode ( The sensing electrode SE, wherein a portion of the driving electrode DE and the sensing electrode SE overlap each other is referred to as a node NO, and a mutual capacitance type capacitive touch sensing method is a sensing touch. The amount of capacitance change at each node on the panel. Assuming that the capacitive touch sensor includes J driving electrodes and K sensing electrodes, a total of (J x K) nodes are formed. Since each driving electrode provides a driving voltage and intersects with K sensing electrodes, each node is coupled with a mutual inductance capacitor Cm, and each mutual sensing capacitor Cm is coupled to the sensing voltage. When the capacitive touch panel is touched, the mutual inductance capacitor Cm corresponding to the node at the touch will change accordingly, and the coupled sensing voltage will also change, so this characteristic can be used to judge the capacitive touch. Whether the control panel is touched.

At the same time, the sensing voltages sensed by the adjacent sensing electrodes are all from the same driving electrode, and then sensed by the sensing circuit. The sensing method of the sensing circuit may be a current sensing type, a charge transfer type or a voltage sensing type, and the sensing methods may be in the form of a single-ended input or a differential input, wherein the differential input is in the form of a differential input. The anti-noise effect is best.

For example, as shown in FIG. 2, the capacitive touch sensor CT includes eight driving lines Y0~Y7 and eight sensing lines X0~X7, so a total of 64 nodes N00, N10, N20, are formed. .., N67, N77. However, since the sensing voltages V _S0 and V _S1 sensed by the adjacent sensing lines X0 and X1 at the same time are respectively the driving voltage V _D0 supplied from the same driving line Y0 by the nodes N00 and N10, that is, adjacent The sensing voltages V _S0 and V _S1 sensed by the sensing electrodes X0 and X1 have the same phase, and therefore, the sensing circuit SC will sense the sensing voltages V _S0 and V of the adjacent sensing lines X0 and X1 of the differential input. _S1 subtraction can reduce the influence of noise, but the signal with the same phase will be reduced after the signal is subtracted, so the signal-to-noise ratio can not be effectively improved, resulting in the performance of the capacitive touch display device. restricted.

In view of this, the present invention provides a capacitive touch display device to solve the above problems.

One aspect of the present invention is to provide a capacitive touch display device. In one embodiment, the capacitive touch display device includes at least a capacitive touch panel and a capacitive touch sensor. The capacitive touch sensor is disposed on the capacitive touch panel for sensing touch points formed on the capacitive touch panel. The capacitive touch sensor includes a plurality of driving lines, a plurality of sensing lines, and a sensing circuit.

The plurality of driving lines includes first driving lines and second driving lines arranged adjacent to each other in the first direction. The first driving line and the second driving line are respectively used to input the first driving voltage and the second driving voltage having different phases and different voltages. The plurality of sensing lines include a first sensing line and a second sensing line arranged adjacent to each other in the second direction. The first sensing line overlaps with the first driving line to form a first node and does not overlap with the second driving line, and the second sensing line overlaps with the second driving line to form a second node without overlapping the first driving line. The first node and the second node respectively couple the first mutual inductance capacitor and the second mutual inductance capacitance, and the first mutual inductance capacitance and the second mutual inductance capacitance respectively couple the first sensing voltage and the second sensing voltage, respectively, and are respectively performed by the first The sensing line and the second sensing line output the first sensing voltage and the second sensing voltage. The sensing circuit receives the first sensing voltage and the second sensing voltage and subtracts the first sensing voltage from the second sensing voltage to obtain a sensing voltage difference.

In an embodiment, when the sensing voltage difference obtained by the sensing circuit increases, the signal-to-noise ratio corresponding to the sensing voltage difference also increases.

In an embodiment, if the first driving voltage and the second driving voltage both have a positive phase, the sensing voltage difference is closer to the first sensing voltage minus the second sensing voltage. And the sensing voltage difference corresponds to a first signal to noise ratio.

In one embodiment, if the first driving voltage has a positive phase and the second driving voltage is zero, the sensing voltage difference is close to a value of the first sensing voltage, and the sensing voltage difference is Corresponding to a second signal to noise ratio. The second signal to noise ratio is greater than the first signal to noise ratio.

In one embodiment, if the first driving voltage has a positive phase and the second driving voltage has a negative phase, the sensing voltage difference is closer to the first sensing voltage plus the second sensing voltage. And the sensed voltage difference corresponds to a third signal to noise ratio. The third signal ratio is greater than the first signal to noise ratio.

In one embodiment, if the first driving voltage is zero and the second driving voltage has a negative phase, the sensing voltage difference is closer to the value of the second sensing voltage, and the sensing voltage difference is It corresponds to a fourth signal to noise ratio. The fourth signal to noise ratio is greater than the first signal to noise ratio.

In one embodiment, the sensing circuit includes a differential amplifying unit, the differential amplifying unit includes a first input end, a second input end, and an output end, and the first input end and the second input After receiving the first sensing voltage and the second sensing voltage respectively, the differential amplifying unit subtracts the second sensing voltage from the first sensing voltage to obtain the sensing voltage difference and the sense After the measured voltage difference is amplified, the amplified voltage is sensed by the output terminal.

Compared with the prior art, the capacitive touch display device according to the present invention changes the regular arrangement of the conventional electrodes into an interlaced arrangement through the change of the electrode arrangement of the capacitive touch sensor, so that the same time The sensing voltages sensed by the adjacent sensing electrodes may be respectively from different driving electrodes that provide different driving voltages, that is, the sensing voltages sensed by the adjacent sensing electrodes may have different phases, and therefore, the sensing circuit will be poor. The subtraction of the sensing voltage of the adjacent sensing electrodes of the dynamic input can not only effectively reduce the influence of the noise, but also the intensity of the signal itself is not reduced, so the signal-to-noise ratio can be effectively improved. Therefore, the capacitive touch sensor of the present invention can more accurately sense the touch point of the capacitive touch panel to greatly reduce the probability of misjudgment.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

According to an embodiment of the invention, a capacitive touch display device is provided. In this embodiment, the capacitive touch display device includes at least a capacitive touch panel and a capacitive touch sensor, and the capacitive touch sensor can adopt a mutual capacitance type touch sensing. The method senses the touch point formed on the capacitive touch panel, but is not limited thereto. Please refer to FIG. 3. FIG. 3 is a schematic diagram showing the staggered arrangement of the nodes of the driving lines (electrodes) and the sensing lines (electrodes) of the capacitive touch display device of the present invention.

As shown in FIG. 3, the drive lines Y0 to Y7 and the sensing lines X0 to X15 are formed with a total of 64 nodes N00, N20, ..., N11, N31, ..., N137, N157. Compared with the prior art of FIG. 2, the number of nodes and the number of driving lines of FIG. 3 are the same as those shown in FIG. 2, but the number of sensing lines of FIG. 3 is significantly doubled compared with the number of sensing lines shown in FIG. A driving line does not overlap with each sensing line to form a node, and each sensing line does not overlap with each driving line to form a node. Please refer to FIG. 4. FIG. 4 is a diagram showing a layout of a driving line and a sensing line of the present invention. It should be noted that, due to space limitations, FIG. 4 only draws the portions of the upper half of the driving lines Y0 to Y3.

In more detail, taking the two adjacent driving lines Y0 and Y1 as an example, the driving line Y0 overlaps with the sensing lines X0, X2, X4, ..., X12 and X14 to form nodes N00, N20, N40, respectively. .., N120 and N140, and the driving line Y1 overlaps with the sensing lines X1, X3, X5, ..., X13 and X15 to form nodes N11, N31, N51, ..., N131 and N151, and the rest may be And so on, so I won't go into details here.

Taking the two adjacent sensing lines X0 and X1 as an example, the sensing line X0 overlaps with the driving lines Y0, Y2, Y4 and Y6 to form nodes N00, N02, N04 and N06, respectively, and the sensing line X1 is respectively connected to the driving line. Y1, Y3, Y5, and Y7 overlap to form nodes N11, N13, N15, and N17, and the rest can be deduced by analogy, and will not be further described herein.

It should be specially noted that, at the same time, the adjacent two driving lines Y0 and Y1 are used to respectively input driving voltages V _D0 and V _D1 having different phases and different voltages. In practical applications, the magnitudes of the driving voltages V _D0 and V _D1 at the same time may be adjusted according to actual needs, as long as the phase of the driving voltage V _D0 is different from the phase of V _D1 .

Since the driving voltage V _D0 input by the driving line Y0 flows through the node N00 formed by overlapping with the sensing line X0, the mutual inductance capacitor Cm is coupled at the node N00, and the sensing voltage Vs00 is coupled to the sensing line X0. As for the driving voltage V _D1 input to the driving line Y1 flowing through the node N11 formed by overlapping with the sensing line X1, the mutual inductance capacitor Cm is coupled at the node N11, and the sensing voltage Vs11 is coupled to the sensing line X1. Therefore, the sensing circuit SC receives the sensing voltages Vs00 and Vs11 from the sensing line X0 and the sensing line X1, respectively, and subtracts the sensing voltages Vs00 and Vs11 to obtain a sensing voltage difference. It should be noted that the sensing voltage difference obtained by the sensing circuit SC will affect the signal-to-noise ratio. When the sensing voltage difference increases, the signal-to-noise ratio will also increase.

In practical applications, the sensing circuit SC includes a differential amplifying unit DA, and the differential amplifying unit DA includes a first input terminal +, a second input terminal - and an output terminal OUT. After the first input terminal + and the second input terminal respectively receive the sensing voltages Vs00 and Vs11, the differential amplifying unit DA subtracts the sensing voltage Vs00 from Vs11 to obtain a sensing voltage difference and amplifies the sensing voltage difference. After that, the amplified sensing voltage difference is outputted by the output terminal OUT, and after the subsequent signal processing procedure, it is determined whether the capacitive touch panel is touched.

Next, the influence of the driving voltages with different phases and different voltages input by adjacent driving lines on the signal-to-noise ratio will be explained through several different actual situations.

In the first case, it is assumed that at the same time, the driving voltage V _D0 input by the driving line Y0 and the driving voltage V _D1 input by the driving line Y1 have a positive phase, and the noise of the two will substantially abut each other. The sensing voltage difference ΔVs1 obtained by the pin and sensing circuit SC is close to the sensing voltage Vs00 of the sensing line X0 minus the sensing voltage Vs11 of the sensing line X1, and the sensing voltage difference ΔVs1 is Corresponding to the first signal to noise ratio SNR1. Similarly, the case where the driving voltages V _D0 and V _D1 both have a negative phase is similar, and will not be further described herein.

In the second case, it is assumed that at the same time, the driving voltage V _D0 input by the driving line Y0 has a positive phase, and the driving voltage V _D1 input by the driving line Y1 is zero, since the noise of the two will be substantially The sensing voltage difference ΔVs2 obtained by the sensing circuit SC is close to the value of the sensing voltage Vs00 of the sensing line X0, and the sensing voltage difference ΔVs2 corresponds to the second signal to noise ratio SNR2. . Compared with the first case, since the sensing voltage Vs00 does not have to subtract the in-phase sensing voltage Vs11, the sensing voltage difference ΔVs2 is larger than the sensing voltage difference ΔVs1, so the second signal-to-noise ratio SNR2 It should be larger than the first signal ratio SNR1.

In the third case, it is assumed that at the same time, the driving voltage V _D0 input by the driving line Y0 has a positive phase, and the driving voltage V _D1 input by the driving line Y1 has a negative phase, since the noise of the two will be The sensing voltage difference ΔVs3 obtained by the sensing circuit SC is close to the sensing voltage Vs00 of the sensing line X0 plus the sensing voltage Vs11 of the sensing line X1, and the sensing voltage difference is substantially canceled. ΔVs3 corresponds to the third signal to noise ratio SNR3. Compared with the first case, since the sensing voltage Vs00 does not have to be subtracted from the sensing voltage Vs11, but is added to the sensing voltage Vs11, the sensing voltage difference ΔVs3 is larger than the sensing voltage difference ΔVs1. Therefore, the third signal to noise ratio SNR3 should be larger than the first signal to noise ratio SNR1. Similarly, the driving voltage V _D0 input by the driving line Y0 has a negative phase, and the driving voltage V _D1 input by the driving line Y1 has a positive phase, which is similar, and will not be further described herein.

In the fourth case, it is assumed that at the same time, the driving voltage V _D0 input by the driving line Y0 is zero, and the driving voltage V _D1 input by the driving line Y1 has a negative phase, since the noise of the two will be substantially The sensing voltage difference ΔVs4 obtained by the sensing circuit SC is close to the value of the sensing voltage Vs11 of the sensing line X1, and the sensing voltage difference ΔVs4 corresponds to the fourth signal to noise ratio SNR4. . Compared with the first case, since the sensing voltage Vs11 does not have to be subtracted from the sensing voltage Vs00 of the same phase, the sensing voltage difference ΔVs4 is larger than the sensing voltage difference ΔVs1, so the fourth signal-to-noise ratio SNR4 should be larger than the first signal-to-noise ratio SNR1.

As shown in FIG. 5A to FIG. 5I, the nodes N00 and N11 having different types are respectively shown, and the contact area is increased by changing the shape of the electrode, but not limited thereto. FIG. 6 illustrates another version of the layout of the drive line and the sense line of the present invention. It should be noted that, limited to the length, FIG. 6 only draws the portions of the upper half of the driving lines Y0 to Y3.

In the above-described embodiments of the present invention, the number of drive lines is the same as that of the prior art (Fig. 2), but the number of sense lines is twice as large as the number of sense lines of the prior art (Fig. 2). In fact, the present invention also includes the case where the number of sensing lines is identical to the prior art (Fig. 2), but the number of driving lines is twice as large as the number of driving lines of the prior art (Fig. 2). Please refer to FIG. 7. FIG. 7 illustrates an embodiment in which the number of sensing lines is the same as that of the prior art (FIG. 2) but the number of driving lines is multiplied from the prior art (FIG. 2). It should be noted that, due to space limitations, FIG. 7 only draws the portions of the sensing lines X0 to X3 in the left half.

Different from the above embodiment, if the two adjacent sensing lines X0 and X1 in FIG. 7 are taken as an example, the sensing line X0 overlaps with the driving lines Y0, Y2, Y4 and Y6 to form nodes N00, N02, and N04, respectively. And N06, and the sensing line X1 overlaps with the driving lines Y1, Y3, Y5 and Y7 to form nodes N11, N13, N15 and N17, respectively. Taking the two adjacent driving lines Y0 and Y1 as an example, the driving line Y0 overlaps with the sensing lines X0 and X2 to form nodes N00 and N20, respectively, and the driving line Y1 overlaps with the sensing lines X1 and X3 to form a node N11 and N31, the rest can be deduced by analogy, and will not be described here.

It should be specially noted that, at the same time, two adjacent driving lines Y0 and Y1 are used to input two driving voltages having different phases and different voltages, respectively. In practical applications, the magnitudes of the two driving voltages at the same time can be adjusted according to actual needs. As long as the phases of the two driving voltages are different, the sensing voltages sensed by the adjacent sensing lines X0 and X1 have different phases. Therefore, when the sensing circuit subtracts the sensing voltages of the adjacent sensing electrodes X0 and X1 of the differential input, the influence of the noise can be effectively reduced, and the signal-to-noise ratio can be significantly improved.

Compared with the prior art, the capacitive touch display device according to the present invention changes the regular arrangement of the conventional electrodes into an interlaced arrangement through the change of the electrode arrangement of the capacitive touch sensor, so that the same time The sensing voltages sensed by the adjacent sensing electrodes may be respectively from different driving electrodes that provide different driving voltages, that is, the sensing voltages sensed by the adjacent sensing electrodes may have different phases, and therefore, the sensing circuit will be poor. The subtraction of the sensing voltage of the adjacent sensing electrodes of the dynamic input can not only effectively reduce the influence of the noise, but also the intensity of the signal itself is not reduced, so the signal-to-noise ratio can be effectively improved. Therefore, the capacitive touch sensor of the present invention can more accurately sense the touch point of the capacitive touch panel to greatly reduce the probability of misjudgment.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

DE. . . Drive electrode

SE. . . Sense electrode

NO. . . node

Cm. . . Mutual inductance capacitor

Y0~Y7. . . Drive line

X0~X15. . . Sensing line

N00,...,N157. . . node

C1~C2. . . capacitance

V _D0 , V _D1 . . . Driving voltage

CT. . . Capacitive touch sensor

SC. . . Sense circuit

DA. . . Differential amplification unit

+. . . First input

-. . . Second input

OUT. . . Output

A1~A4. . . Amplifier

SW1~SW4. . . switch

FIG. 1 is a schematic diagram showing the coupling of a mutual inductance capacitor on a node formed by overlapping a driving electrode and a sensing electrode.

FIG. 2 is a schematic diagram showing a node arrangement formed by overlapping driving electrodes and sensing electrodes of a conventional capacitive touch display device.

3 is a schematic diagram showing a node arrangement of a driving electrode and a sensing electrode of the capacitive touch display device of the present invention.

4 is a diagram showing an embodiment of a layout of a driving electrode and a sensing electrode of the present invention.

5A to 5I respectively show various nodes having different types.

6 is another embodiment of the layout of the drive and sense electrodes of the present invention.

FIG. 7 illustrates an embodiment in which the number of sensing lines is the same as that of FIG. 2 but the number of driving lines is multiplied by FIG.

Y0~Y7. . . Drive line

X0~X15. . . Sensing line

V _D0 , V _D1 . . . Driving voltage

C1~C2. . . capacitance

SC. . . Sense circuit

DA. . . Differential amplification unit

+. . . First input

-. . . Second input

OUT. . . Output

A1~A4. . . Amplifier

SW1~SW4. . . switch

N00,...,N157. . . node

Claims (10)

A capacitive touch display device includes: a capacitive touch panel; and a capacitive touch sensor disposed on the capacitive touch panel, the capacitive touch sensor comprising: a plurality of The driving line includes a first driving line and a second driving line arranged adjacent to each other in a first direction. The first driving line and the second driving line are respectively used for inputting at a time. a first driving voltage and a second driving voltage of the different phases and different voltages; a plurality of sensing lines comprising a first sensing line and a second sensing line arranged adjacent to each other in a second direction, The first sensing line overlaps with the first driving line to form a first node and does not overlap with the second driving line, and the second sensing line overlaps with the second driving line to form a second node; A driving line is overlapped, and the first node and the second node respectively respectively form a first mutual inductance capacitor and a second mutual inductance capacitor, and the first mutual inductance capacitor and the second mutual inductance capacitor respectively couple a first sensing voltage And a second sense voltage, and divide The first sensing line and the second sensing line are not output by the first sensing line and the second sensing line; and a sensing circuit is coupled to the plurality of sensing lines, and the sensing circuit receives the first And sensing a voltage and the second sensing voltage and subtracting the first sensing voltage from the second sensing voltage to obtain a sensing voltage difference. The capacitive touch display device of claim 1, wherein when the sensing voltage difference obtained by the sensing circuit is increased, the sensing voltage difference corresponds to a signal-to-noise ratio (Signal- The Noise Ratio, SNR) also increases. The capacitive touch display device of claim 1, wherein if the first driving voltage and the second driving voltage both have a positive phase, the sensing voltage difference approaches the first sensing. The voltage is subtracted from the value of the second sensing voltage, and the sensed voltage difference corresponds to a first signal to noise ratio. The capacitive touch display device of claim 1, wherein if the first driving voltage has a positive phase and the second driving voltage is zero, the sensing voltage difference approaches the first sense The value of the voltage is measured, and the sensed voltage difference corresponds to a second signal to noise ratio. The capacitive touch display device of claim 1, wherein if the first driving voltage has a positive phase and the second driving voltage has a negative phase, the sensing voltage difference approaches the first The sensing voltage is added to the value of the second sensing voltage, and the sensing voltage difference corresponds to a third signal to noise ratio. The capacitive touch display device of claim 1, wherein if the first driving voltage is zero and the second driving voltage has a negative phase, the sensing voltage difference approaches the second sense The value of the voltage is measured, and the sensed voltage difference corresponds to a fourth signal to noise ratio. The capacitive touch display device of claim 3, wherein the second signal-to-noise ratio is greater than the first signal-to-noise ratio. The capacitive touch display device of claim 3, wherein the third signal-to-noise ratio is greater than the first signal-to-noise ratio. The capacitive touch display device of claim 3, wherein the fourth signal-to-noise ratio is greater than the first signal-to-noise ratio. The capacitive touch display device of claim 1, wherein the sensing circuit comprises a differential amplifying unit, the differential amplifying unit comprises a first input end, a second input end and an output end After the first input end and the second input end respectively receive the first sensing voltage and the second sensing voltage, the differential amplifying unit subtracts the second sensing voltage from the first sensing voltage After the sensing voltage difference is obtained, and the sensing voltage difference is amplified, the amplified sensing voltage difference is outputted by the output terminal.