CN106155428A - Touch sensing device and parallel sensing circuit - Google Patents

Abstract

A parallel sensing circuit suitable for a touch panel includes a plurality of summing circuits, each of which has a plurality of input terminals for receiving a plurality of sensing signals provided by a corresponding receiving terminal of the touch panel. The input terminals of each summing circuit add or subtract the sensing signals, thereby generating a sum signal at a corresponding output terminal of the summing circuit; and a plurality of receiving circuits, respectively coupled to the output terminals of the summing circuits, for processing the sum signals, thereby generating sum values, respectively, for determining a touch position.

Description

Touch sensing device and parallel sensing circuit

technical field

The invention relates to touch sensing, in particular to a concurrent sensing circuit suitable for a touch panel.

Background technique

The touch sensing device can be combined with a display to form a touch display, which combines touch technology and display technology so that users can directly interact with displayed objects. Capacitive touch sensing is one of many different touch sensing technologies.

A capacitive touch sensing device includes a conductor (such as ITO) and an insulator (such as glass). When the human body (as another conductor) touches the surface of the capacitive touch sensing device, it will change the formed electrostatic field, which is reflected in the change of the capacitance value, so as to determine the touch position.

A mutual-capacitance touch sensing device is a type of capacitive touch sensing device. FIG. 1A shows a schematic diagram of a mutual capacitance touch sensing device 100, which is composed of column electrodes and row electrodes, such as the 3×5 array shown in FIG. 1A. Driving signals are applied to the transmitting terminals TX1-TX3, and sensing signals are collected at the receiving terminals RX1-RX5.

A self-capacitance touch sensing device is another capacitive touch sensing device. FIG. 1B shows a schematic diagram of a self-capacitance touch sensing device 102 , which is composed of column electrodes and row electrodes, such as the 3×5 array shown in FIG. 1B . Different from the mutual-capacitance touch sensing device 100 , the self-capacitance touch sensing device 102 only has receiving terminals RX11 - RX15 and RX21 - RX23 for collecting sensing signals.

Whether it is a mutual capacitance touch sensing device 100 or a self-capacitance touch sensing device 102, each receiving end (RX) is correspondingly coupled to a receiving circuit (or receiving unit) 11, such as an analog-to-digital converter (ADC) . As shown in FIG. 1A or FIG. 1B , the number of receiving circuits 11 is equal to the number of receiving terminals. Therefore, these architectures require large circuit area and cost, especially for large-scale touch sensing devices. The architecture shown in FIG. 1A or FIG. 1B also has drawbacks for small-sized touch-sensing devices with limited space or power supply.

In order to improve the aforementioned defects, FIG. 2A and FIG. 2B propose an improved architecture in which the number of receiving circuits 11 used by the touch sensing device 200 is less than the number of receiving terminals (RX). First, in the first stage shown in FIG. 2A , the receiving circuit 11 receives (and processes) the sensing signals corresponding to some receiving ends (eg, RX1 - RX3 ). Then, in the second stage shown in FIG. 2B , the same receiving circuit 11 receives (and processes) the sensing signals corresponding to the remaining receiving ends (eg, RX4 - RX6 ). Since the receiving circuit 11 in FIG. 2A and FIG. 2B adopts a time-sharing method, its structure will cause a time delay when processing all sensing signals. This defect will be more serious for the in-cell touch display, because its display and touch sensing are performed sequentially, so the effective time of touch sensing is longer than that of general touch sensing devices (such as Fig. 1A or those shown in Figure 1B) come shorter.

In view of the disadvantages of large circuit area or long delay in conventional touch sensing devices, there is an urgent need to propose a novel touch sensing device to reduce the circuit area without long delay.

Contents of the invention

In view of the above, one of the objectives of the embodiments of the present invention is to provide a parallel sensing circuit suitable for a touch panel to save circuit area and cost without causing delay.

According to an embodiment of the present invention, the touch sensing device includes a touch panel, a plurality of summing circuits, and a plurality of receiving circuits. The touch panel includes column electrodes and row electrodes. Each summing circuit has a plurality of input ends for receiving a plurality of sensing signals provided by corresponding receiving ends of the touch panel, and these input ends of each summing circuit add up or subtract these sensing signals, thereby generating a sum The signal is at the corresponding output of the sum circuit. The receiving circuits are respectively coupled to the output terminals of the sum circuits for processing the sum signals, thereby generating sum values respectively, and determining the touch position accordingly.

Description of drawings

FIG. 1A shows a schematic diagram of a mutual capacitance touch sensing device.

FIG. 1B shows a schematic diagram of a self-capacitive touch sensing device.

2A and 2B are schematic diagrams of a time-sharing touch sensing device.

FIG. 3 shows a schematic diagram of a touch sensing device according to an embodiment of the present invention.

FIG. 4 illustrates the timing of the sum circuit of FIG. 3 .

FIG. 5 shows a circuit diagram of the sum circuit of FIG. 3 .

[Description of Reference Signs]

100 Mutual capacitance touch sensing device

102 self-capacitive touch sensing device

200 touch sensing device

11 Receiver circuit

300 touch sensing device

31 Touch panel

32 parallel sensing circuit

321 and circuit

322 receiving circuit

51 amplifier

TX1～TX3 Transmitter

RX1～RX6 Receiver

RX11～RX15 Receiver

RX21～RX23 Receiver

SWRX1 first switch

~SWRX1 second switch

SWRX2 first switch

~SWRX2 second switch

SWRX3 first switch

~SWRX3 second switch

CRX1～CRX3 equivalent capacitance

S node

C capacitor

detailed description

FIG. 3 shows a schematic diagram of a touch sensing device 300 according to an embodiment of the present invention. The touch sensing device 300 of this embodiment can be combined with a display to form a touch screen, but it is not limited thereto.

The touch sensing device 300 of this embodiment includes a touch panel 31 and a parallel sensing circuit 32 suitable for the touch panel 31 . The touch panel 31 can be a resistive touch panel, a capacitive touch panel or an optical touch panel. The touch panel 31 may include column electrodes and row electrodes, such as the 3×6 array shown in FIG. 3 . In this embodiment, the receiving terminals RX1-RX6 correspond to the row electrodes, and sensing signals are provided (or generated) at the receiving terminals RX1-RX6.

The parallel sensing circuit 32 of this embodiment includes a plurality of summing circuits 321 . Each sum circuit 321 has multiple input terminals for receiving multiple sensing signals from corresponding receiving terminals. For example, the sum circuit 321 on the right side of FIG. 3 has three input terminals for receiving three sensing signals corresponding to the receiving terminals RX1 - RX3 . In a similar situation, the sum circuit 321 on the left side of FIG. 3 has three input terminals for receiving three sensing signals corresponding to the receiving terminals RX4 - RX6 . It should be noted that each receiver corresponds to one and only one sum circuit 321 . According to one of the features of this embodiment, the sum circuit 321 is used to sum or subtract the sensing signals, thereby generating a sum signal at the corresponding output terminal.

The parallel sensing circuit 32 of this embodiment further includes a plurality of receiving circuits (or receiving units) 322 , such as analog-to-digital converters. The receiving circuits 322 are respectively coupled to the output terminals of the corresponding sum circuits 321 . In this embodiment, the number of summing circuits 321 is equal to the number of receiving circuits 322 . The receiving circuit 322 is used for processing the sum signal, thereby generating a sum value for determining the touch position.

FIG. 4 illustrates the timing of the sum circuit 321 of FIG. 3 . FIG. 4 only shows the time sequence from time t0 to t3, and subsequent time sequences can be obtained through repetition. In the drawings, RX1 ˜ RX6 represent corresponding sensing signals, “+” represents that the sum circuit 321 performs an addition operation on the corresponding sensing signals, and “-” represents that the sum circuit 321 performs a subtraction operation on the corresponding sensing signals. During the three periods of this embodiment, the combinations of addition and subtraction at the input end of the sum circuit 321 are different. For example, at time t0, the sum circuit 321 has a combination of "+, +, -", at time t1, the sum circuit 321 has a combination of "+, -, +", and at time t2, the sum circuit 321 has a combination of "-, +,+" operation combination. Generally speaking, during n consecutive periods, the combinations of the addition and subtraction operations of the n input terminals of the sum circuit 321 are different, wherein n is a positive integer greater than two.

Assuming that the right-side sum circuit 321 sequentially obtains the sum values a, b and c from the receiving circuit 322 during the three periods in FIG. 4 , it can be expressed as:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\\ \mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; b</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; c</span>}\end{array}\right.$

or

$\left[\begin{array}{ccc}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ <span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\\ \mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; RX</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; a</span>}\\ \mathrm{<span\; class="notranslate">\; b</span>}\\ \mathrm{<span\; class="notranslate">\; c</span>}\end{array}\right]$

After the receiving circuit 322 receives the sum values a, b and c, the sensing signals RX1 - RX3 can be obtained accordingly.

FIG. 5 shows a circuit diagram of the sum circuit 321 of FIG. 3 . In the figure, CRX1 , CRX2 and CRX3 represent equivalent capacitances of the receiving terminals RX1 - RX3 of the touch panel 31 . For the corresponding input end of the receiving end RX1, when performing an addition operation, close the first switch SWRX1 to receive a preset positive voltage (for example, 3V); otherwise, when performing a subtraction operation, close the second switch SWRX1 to ground. In a similar situation, for the corresponding input end of the receiving end RX2, when performing an addition operation, close the first switch SWRX2 to receive a preset positive voltage (for example, 3V); otherwise, when performing a subtraction operation, close the second switch SWRX2 to receive grounded. Furthermore, for the corresponding input terminal of the receiving terminal RX3, when performing an addition operation, close the first switch SWRX3 to receive a preset positive voltage (for example, 3V); otherwise, when performing a subtraction operation, close the second switch SWRX3 to ground .

The equivalent capacitors CRX1 , CRX2 and CRX3 corresponding to the receiving ends RX1 ˜ RX3 of the touch panel 31 are coupled to the node S, followed by an amplifier 51 (such as an operational amplifier). The capacitor C is coupled between the output terminal and the input terminal of the amplifier 51 . The capacitor C is charged when an addition operation is performed, and is discharged when a subtraction operation is performed.

According to the above-mentioned embodiment, since the number of receiving circuits 32 is less than that of the receiving end, circuit area and cost can be saved. Therefore, this embodiment is more suitable for large-sized touch sensing devices than the structure shown in FIG. 1A or FIG. 1B . In addition, since the receiving circuit 32 processes all the sensing signals simultaneously instead of the time-sharing method as shown in FIG. 2A/FIG. 2B , no delay will be generated in this embodiment.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the claims of the present invention; all other equivalent changes or modifications that do not deviate from the spirit disclosed by the invention shall be included in the appended claims In the range.

Claims (14)

1. a touch sensing device, comprises:

One contact panel, comprises row electrode and row electrode；

Multiple and circuit, each and circuit has multiple input, in order to receive the corresponding of this contact panel Multiple sensing signals that receiving terminal is provided, these inputs each and circuit add up or deduct these senses Survey signal, thus produce one and signal in the corresponding output end of this and circuit；And

Multiple reception circuit, are respectively coupled to the outfan of these and circuit, in order to process this and signal, Thus produce respectively and be worth, determine touch position according to this.

2. touch sensing device as claimed in claim 1, wherein each receiving terminal phase of this contact panel Answer one and only one and circuit.

3. touch sensing device as claimed in claim 1, each of which receives circuit and comprises a simulation extremely Digital converter.

4. touch sensing device as claimed in claim 1, wherein these are equal to these with the number of circuit Receive the number of circuit.

5. touch sensing device as claimed in claim 1, in continuous multiple periods, should and this of circuit A little inputs to add computing different with the combination subtracting computing.

6. touch sensing device as claimed in claim 1, in n continuous multiple periods, is somebody's turn to do and circuit N input to add computing different with the combination subtracting computing, wherein n is the positive integer more than two.

7. touch sensing device as claimed in claim 1, each of which should comprise with circuit:

First switch, corresponding to each input, when performing to add computing, this first switch Guan Bi is to connect Receive one and preset positive voltage；

Second switch, corresponding to each input, when performing to subtract computing, this second switch closes to connect Ground；

One amplifier, is coupled to this first switch, this second switch and the correspondingly received end of this contact panel； And

One capacitor, is coupled between the outfan of this amplifier and input, when performing to add computing pair This capacitor charges, when performing to subtract computing to this capacitor discharge.

8. a parallel type sensing circuit, comprises:

Multiple and circuit, each and circuit has multiple input, in order to receive the corresponding of a contact panel Multiple sensing signals that receiving terminal is provided, these inputs each and circuit add up or deduct these senses Survey signal, thus produce one and signal in the corresponding output end of this and circuit；And

Multiple reception circuit, are respectively coupled to the outfan of these and circuit, in order to process this and signal, Thus produce respectively and be worth, determine touch position according to this.

9. parallel type sensing circuit as claimed in claim 8, wherein each receiving terminal of this contact panel Corresponding one and only one and circuit.

10. parallel type sensing circuit as claimed in claim 8, each of which receives circuit and comprises a mould Intend to digital converter.

11. parallel type sensing circuits as claimed in claim 8, wherein these are equal to the number of circuit These receive the number of circuit.

12. parallel type sensing circuits as claimed in claim 8, in continuous multiple periods, are somebody's turn to do and circuit These inputs to add computing different with the combination subtracting computing.

13. parallel type sensing circuits as claimed in claim 8, in n continuous multiple periods, should and N input of circuit to add computing different with the combination subtracting computing, wherein n is the positive integer more than two.

14. parallel type sensing circuits as claimed in claim 8, each of which should comprise with circuit:

First switch, corresponding to each input, when performing to add computing, this first switch Guan Bi is to connect Receive one and preset positive voltage；

Second switch, corresponding to each input, when performing to subtract computing, this second switch closes to connect Ground；

One amplifier, is coupled to this first switch, this second switch and the correspondingly received end of this contact panel； And

One capacitor, is coupled between the outfan of this amplifier and input, when performing to add computing pair This capacitor charges, when performing to subtract computing to this capacitor discharge.