Touch-control chip, touch-control apparatus, touch-control screen and electronic device

Abstract

Disclosed in the present invention are a touch-control chip, a touch-control apparatus, a touch-control screen and an electronic device. The touch-control chip is used for connecting to a touch-control screen, which comprises a common voltage line and at least two touch-control units. Each touch-control unit comprises a touch-control electrode, a function changeover switch and a control circuit, wherein a first end of each touch-control electrode is connected to the common voltage line by means of the function changeover switch; and each control circuit is connected to a control end of the function changeover switch, and a connection node between the function changeover switch and the touch-control electrode. A common voltage end is connected to the common voltage line. A coding signal end is connected to second ends of at least two touch-control electrodes. A control signal end is connected to the control circuits, and is used for outputting control signals to the control circuits, such that the control circuits control the switching on or switching off of the function changeover switches. By means of the touch-control chip, during the coding process of a touch-control screen, potentials of control ends of function changeover switches can be adjusted on the basis of a change in a coding potential, thereby realizing a TSP function mode and an EMR function mode.

Description

Touch chip, touch device, touch screen and electronic device TECHNICAL FIELD

[0001] The present application relates to the technical field of touch control, in particular to a touch chip, a touch device, a touch screen and an electronic device. BACKGROUND

[0002] In order to make the touch screen not only support the touch operation of the finger, but also take into account the touch operation of the electromagnetic pen, the existing touch screen can use the film layer of the capacitive touch screen (touch screen panel, hereinafter referred to as TSP) as the wire of the electromagnetic touch screen (Electro magnetic Resonance, hereinafter referred to as EMR), and a function switching switch is arranged, which is used to connect the touch electrode and the common voltage line. When the function switching switch is closed, the touch screen can enter the TSP function mode, and when the function switching switch is opened, the touch screen can enter the EMR function mode. As a function switching switch to distinguish the TSP function mode and the EMR function mode, a fixed voltage is generally output by the touch chip to control the opening or closing of the function switching switch. This way makes the voltage at both ends of the function switching switch fluctuate greatly during the coding process of the touch screen, which affects the normal work of the touch screen.

[0003] SUMMARY

[0004] The embodiments of the present application provide a touch chip, a touch device, a touch screen and an electronic device to solve the problem that the voltage at both ends of the function switching switch arranged between the touch electrode and the common voltage line fluctuates greatly during the coding process of the touch screen, which affects the normal work of the touch screen.

[0005] A touch chip is used to connect a touch screen, the touch screen includes a common voltage line and at least two touch units; each touch unit includes a touch electrode, a function switching switch and a control circuit; the first end of each touch electrode is connected to the common voltage line through a function switching switch; each control circuit is connected to the control end of the function switching switch and the connection node between the function switching switch and the touch electrode.

[0006] The touch chip includes a common voltage end, a coding signal end and a control signal end.

[0007] The common voltage end is connected to the common voltage line.

[0008] The coding signal end is connected to the second end of at least two touch electrodes.

[0009] The control signal end is connected with the control circuit, and the control signal end is used for outputting a control signal to the control circuit, so that the control circuit controls the function switch to open or close.

[0010] Preferably, each control circuit comprises a first capacitor and a switch circuit; one end of the first capacitor is connected with the control end of the function switch, and the other end of the first capacitor is connected with a connection node between the function switch and the touch electrode; the second end of the switch circuit is connected with the control end of the function switch;

[0011] The control signal end comprises a reference voltage end and a switch signal end; the reference voltage end is connected with the first end of the switch circuit, and the switch signal end is connected with the third end of the switch circuit;

[0012] The switch signal end outputs a control signal to the switch circuit, so that the switch circuit opens or closes, and the reference voltage end outputs a reference voltage to the switch circuit, based on which the function switch is controlled to open or close.

[0013] Preferably, the common voltage end is connected with the common voltage line through a state switch;

[0014] The reference voltage comprises a first reference voltage used for controlling the function switch to close;

[0015] The switch signal end is used for outputting a first control signal to the switch circuit, so that the switch circuit opens, and the reference voltage end is used for outputting the first reference voltage to the switch circuit, so as to control the function switch to close and initialize the potential of the control end of the function switch;

[0016] The switch signal end is used for outputting a second control signal to the switch circuit, so that the switch circuit closes, the function switch is maintained in a closed state, and the potential of the control end of the function switch follows the change of the touch code potential of the touch electrode;

[0017] When the state switch is in a conductive state, the common voltage end is used for outputting a common voltage to the common voltage line, and the touch code signal end is used for outputting a first touch code signal to the touch electrode, so that the touch screen enters a TSP function mode.

[0018] Preferably, the reference voltage comprises a second reference voltage used for controlling the switch circuit to close;

[0019] When the switch signal end is used for outputting a second control signal to the switch circuit, the reference voltage end outputs the second reference voltage to the switch circuit, so that the switch circuit is maintained in a closed state.

[0020] Preferably, the code signal end is configured to output a first code signal to at least two of the touch electrodes simultaneously.

[0021] Preferably, the common voltage end is connected to the common voltage line through a state switch.

[0022] The reference voltage includes a third reference voltage configured to control the function switch to open.

[0023] The switch signal end is configured to output a first control signal to a switch circuit to make the switch circuit open, and the reference voltage end is configured to output the third reference voltage to the switch circuit to control the function switch to open.

[0024] When the state switch is in an open state, the code signal end is configured to output a second code signal to the touch electrodes to make the touch screen enter an EMR function mode.

[0025] Preferably, the common voltage line includes a first common voltage line connected to at least three touch electrodes.

[0026] The code signal end is configured to output a second code signal to the at least three touch electrodes corresponding to the same first common voltage line one by one.

[0027] Preferably, the common voltage line includes a second common voltage line connected to two touch electrodes.

[0028] The code signal end is configured to output a second code signal to the two touch electrodes corresponding to the same second common voltage line simultaneously.

[0029] Preferably, the switch circuit includes a first control switch, and a second end of the first control switch is connected to a control end of the function switch.

[0030] The reference voltage end is connected to a first end of the first control switch, and a control end of the first control switch is connected to the switch signal end.

[0031] The switch signal end outputs a first control signal to the first control switch to make the first control switch open, or outputs a second control signal to the first control switch to make the first control switch close.

[0032] Preferably, the switch circuit further includes a voltage lifting circuit connected to a connection node between the second end of the first control switch and the control end of the function switch.

[0033] The control signal end is also used for being connected with the voltage lifting circuit, and outputs a control signal in a second voltage range to the voltage lifting circuit, so that the voltage lifting circuit lifts the control signal in the second voltage range and converts it into a control signal in a first voltage range to control the function switch to open or close.

[0034] Preferably, the voltage lifting circuit comprises a second control switch, a third control switch, a fourth control switch, a fifth control switch and a second capacitor; the second control switch, the third control switch and the fourth control switch are connected in series; the fourth control switch is connected with the control end of the function switch; the second end of the fifth control switch is connected with a connection node between the third control switch and the fourth control switch; the control end of the fifth control switch is connected with the control end of the fourth control switch; and the two ends of the second capacitor are respectively connected with the second end of the fifth control switch and the control end of the fifth control switch.

[0035] The switch signal end comprises a first switch signal end and a second switch signal end; and the control signal end further comprises an input end, a negative voltage supply end and a clock signal end.

[0036] The first switch signal end is used for connecting the control end of the first control switch and outputting a first switch signal to the first control switch; the second switch signal end is used for connecting the control end of the second control switch and outputting a second switch signal to the second control switch; the input end is used for connecting the first end of the second control switch and outputting a first voltage to the second control switch; the negative voltage supply end is used for connecting the control end of the third control switch and outputting a VEE voltage to the third control switch; and the clock signal end is used for connecting the first end of the fifth control switch and outputting a second voltage to the fifth control switch; and the voltage lifting circuit is controlled to lift voltage based on the first switch signal, the second switch signal, the first voltage, the VEE voltage and the second voltage.

[0037] Preferably, the first switch signal end is used for outputting a first control signal to the first control switch to make the first control switch open, and the reference voltage end is used for outputting a first reference voltage to the first control switch to make the function switch close.

[0038] The second switch signal end is used for outputting a first control signal to the second control switch to make the second control switch open, the input end is used for outputting a VDD voltage to the second control switch, and the clock signal end is used for outputting a GND voltage to the fourth control switch to make the fourth control switch and the fifth control switch close.

[0039] Preferably, the first switch signal end is configured to output a first control signal to the first control switch to open the first control switch, and the reference voltage end is configured to output a VEE voltage to the first control switch to open the function switch.

[0040] The second switch signal end is configured to output a first control signal to the second control switch to open the second control switch, the input end is configured to output a VEE voltage to the second control switch, the clock signal end is configured to output a GND voltage to the fifth control switch to close the fourth control switch, and the fifth control switch is opened.

[0041] The first switch signal end is configured to output a second control signal to the first control switch to close the first control switch, the second switch signal end is configured to output a second control signal to the second control switch to close the second control switch, and the clock signal end is configured to output a VEE voltage to the fifth control switch to open the fourth control switch and the fifth control switch.

[0042] Preferably, the touch chip is configured to output a control signal in a first voltage range to the control circuit to control the function switch to open or close.

[0043] A touch device, comprising the above-mentioned touch chip and a state switch.

[0044] One end of the state switch is connected to the common voltage end of the touch chip, and the other end of the state switch is configured to be connected to a common voltage line of a touch screen.

[0045] Preferably, the touch device further comprises a coding circuit.

[0046] One end of the coding circuit is connected to the coding signal end of the touch chip, and the other end of the coding circuit is configured to be connected to a touch electrode of the touch screen.

[0047] Preferably, the touch device further comprises a power supply rail, one end of the power supply rail is connected to the control signal end of the touch chip, and the other end of the power supply rail is configured to be connected to a control circuit of the touch screen.

[0048] The touch chip is configured to output a control signal in a second voltage range.

[0049] The power supply rail is configured to convert the control signal in the second voltage range to output a control signal in a first voltage range to the control circuit to control the function switch to open or close.

[0050] A touch screen configured to be connected to a touch chip, comprising a common voltage line and at least two touch units.

[0051] Each of the touch units comprises a touch electrode, a function switching switch and a control circuit;

[0052] A first end of each of the touch electrodes is connected to the common voltage line through the function switching switch, and a second end of each of the touch electrodes is used for connecting a code signal end of the touch chip; the common voltage line is used for connecting a common voltage end of the touch chip;

[0053] Each of the control circuits is connected to a control end of the function switching switch and a connection node between the function switching switch and the touch electrode, and is further used for connecting a control signal end of the touch chip, for controlling the function switching switch to open or close according to a control signal output by the control signal end.

[0054] Preferably, each of the control circuits comprises a first capacitor and a switch circuit;

[0055] One end of the first capacitor is connected to the control end of the function switching switch, and the other end of the first capacitor is connected to the connection node between the function switching switch and the touch electrode;

[0056] A first end of the switch circuit is used for connecting a reference voltage end of the touch chip, a second end of the switch circuit is connected to the control end of the function switching switch, and a third end of the switch circuit is used for connecting a switch signal end of the touch chip;

[0057] The switch circuit is used for opening or closing based on a control signal output by the switch signal end, and controlling the function switching switch to open or close based on a reference voltage output by the reference voltage end.

[0058] Preferably, the common voltage line is connected to the common voltage end through a state switch;

[0059] The reference voltage comprises a first reference voltage for controlling the function switching switch to close;

[0060] The switch circuit is used for opening based on a first control signal output by the switch signal end, and controlling the function switching switch to close based on the first reference voltage output by the reference voltage end, for initializing a control end potential of the function switching switch;

[0061] The switch circuit is further used for closing based on a second control signal output by the switch signal end, for maintaining the function switching switch in a closed state, and for making the control end potential of the function switching switch follow a code potential of the touch electrode;

[0062] When the state switch is in the on state, the common voltage line is configured to receive a common voltage output by the common voltage terminal, and the touch electrode is configured to receive a first code signal output by the code signal terminal, so that the touch screen enters a TSP function mode.

[0063] Preferably, the reference voltage comprises a second reference voltage for controlling the switch circuit to be closed;

[0064] When the switch circuit is closed based on a second control signal output by the switch signal terminal, the switch circuit is further configured to maintain the closed state based on the second reference voltage output by the reference voltage terminal.

[0065] Preferably, at least two touch electrodes corresponding to the same common voltage line are configured to receive first code signals output by the code signal terminal at the same time.

[0066] Preferably, the common voltage line is connected to the common voltage terminal through a state switch.

[0067] The reference voltage comprises a third reference voltage for controlling the function switch to be opened;

[0068] The switch circuit is further configured to open based on a first control signal output by the switch signal terminal, and to control the function switch to be opened based on the third reference voltage output by the reference voltage terminal.

[0069] When the state switch is in the off state, the touch electrode is configured to receive a second code signal output by the code signal terminal, so that the touch screen enters an EMR function mode.

[0070] Preferably, the common voltage line comprises a first common voltage line connected to at least three touch electrodes.

[0071] At least three touch electrodes corresponding to the same first common voltage line are configured to receive second code signals output by the code signal terminal one by one.

[0072] Preferably, the common voltage line comprises a second common voltage line connected to two touch electrodes.

[0073] Two touch electrodes corresponding to the same second common voltage line are configured to receive second code signals output by the code signal terminal at the same time.

[0074] Preferably, the switch circuit comprises a first control switch.

[0075] The first end of the first control switch is used for connecting a reference voltage end of the touch chip, the second end of the first control switch is connected with the control end of the function switch, and the control end of the first control switch is used for connecting a switch signal end of the touch chip.

[0076] The first control switch is used for being opened based on a first control signal output by the switch signal end or being closed based on a second control signal output by the switch signal end.

[0077] Preferably, the switch circuit further comprises a voltage lifting circuit connected with a connection node between the second end of the first control switch and the control end of the function switch.

[0078] The voltage lifting circuit is further used for connecting a control signal end of the touch chip, for lifting a control signal of a second voltage range output by the common voltage end and converting the control signal into a control signal of a first voltage range, so as to open or close the switch circuit.

[0079] Preferably, the voltage lifting circuit comprises a second control switch, a third control switch, a fourth control switch, a fifth control switch and a second capacitor.

[0080] The second control switch, the third control switch and the fourth control switch are connected in series, and the fourth control switch is connected with the control end of the function switch.

[0081] The control end of the first control switch is used for connecting a first switch signal end of the touch chip to receive a first switch signal output by the first switch signal end.

[0082] The first end of the second control switch is used for connecting an input end of the touch chip to receive a first voltage output by the input end, and the control end of the second control switch is used for connecting a second switch signal end of the touch chip to receive a second switch signal output by the second switch signal end.

[0083] The control end of the third control switch is used for connecting a negative voltage supply end of the touch chip to receive a VEE voltage output by the negative voltage supply end.

[0084] The first end of the fifth control switch is used for connecting a clock signal end of the touch chip, the second end of the fifth control switch is connected with a connection node between the third control switch and the fourth control switch, and the control end of the fifth control switch is connected with the control end of the fourth control switch.

[0085] Two ends of the second capacitor are respectively connected with the second end of the fifth control switch and the control end of the fifth control switch.

[0086] The voltage lifting circuit is configured to control the voltage lifting circuit to perform voltage lifting based on the first switch signal, the second switch signal, the first voltage, the VEE voltage and the second voltage.

[0087] Preferably, the first control switch is configured to open based on the first control signal output by the first switch signal terminal and close based on the first reference voltage output by the reference voltage terminal.

[0088] The second control switch is configured to open based on the first control signal output by the second switch signal terminal, transmit the VDD voltage output by the input terminal to a node between the fourth control switch and the fifth control switch, and receive the GND voltage output by the clock signal terminal by the fifth control switch, so that the fourth control switch is closed and the fifth control switch is opened.

[0089] Preferably, the first control switch is configured to open based on the first control signal output by the first switch signal terminal and close based on the VEE voltage output by the reference voltage terminal.

[0090] The second control switch is configured to open based on the first control signal output by the second switch signal terminal, transmit the VEE voltage output by the input terminal to a node between the fourth control switch and the fifth control switch, and receive the GND voltage output by the clock signal terminal by the fifth control switch, so that the fourth control switch is closed and the fifth control switch is opened.

[0091] The first control switch is configured to close based on the second control signal output by the first switch signal terminal, the second control switch is configured to close based on the second control signal output by the second switch signal terminal, and the fifth control switch receives the VEE voltage output by the clock signal terminal, so that the fourth control switch and the fifth control switch are opened.

[0092] An electronic device comprising the touch control chip and the touch screen, or comprising the touch control device and the touch screen.

[0093] The control signal terminal of the touch control chip controls the function switch to open or close through the control circuit. Since the control circuit is connected not only to the control terminal of the function switch but also to the connection node between the function switch and the touch electrode, the touch electrode can determine the touch potential change of the touch electrode during the touch coding process based on the touch coding signal of the touch control chip 11, and adjust the control terminal potential based on the touch potential change, so as to ensure the implementation of the TSP function mode and the EMR function mode. BRIEF DESCRIPTION OF DRAWINGS

[0094] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0095] Fig. 1 is a schematic diagram of an electronic device in Embodiment 1 of the present application;

[0096] Fig. 2 is a schematic diagram of an electronic device in Embodiment 2 of the present application;

[0097] Fig. 3 is a schematic diagram of an electronic device in Embodiment 3 of the present application;

[0098] Fig. 4 is a structure comparison diagram of a touch screen in Embodiment 3 of the present application and a touch screen in the prior art;

[0099] Fig. 5 is a timing diagram of the touch screen in Embodiment 3 of the present application entering a TSP function mode;

[0100] Fig. 6 is a simulation comparison diagram of the touch screen in Embodiment 3 of the present application and a touch screen in the prior art;

[0101] Fig. 7 is a circuit schematic diagram of the touch screen in Embodiment 3 of the present application entering an EMR function mode;

[0102] Fig. 8 is a first equivalent diagram of the touch screen in Embodiment 3 of the present application entering the EMR function mode;

[0103] Fig. 9 is a timing diagram of the touch screen in Embodiment 3 of the present application entering the EMR function mode;

[0104] Fig. 10 is a second equivalent diagram of the touch screen in Embodiment 3 of the present application entering the EMR function mode;

[0105] Fig. 11 is a third equivalent diagram of the touch screen in Embodiment 3 of the present application entering the EMR function mode;

[0106] Fig. 12 is a timing diagram of the touch screen in Embodiment 3 of the present application entering the TSP function mode and the EMR function mode;

[0107] Fig. 13 is a schematic diagram of an electronic device in Embodiment 4 of the present application;

[0108] Fig. 14 is a timing diagram of the touch screen in Embodiment 4 of the present application entering the TSP function mode;

[0109] Fig. 15 is a state schematic diagram of the touch screen in Embodiment 4 of the present application entering the TSP function mode;

[0110] Fig. 16 is a timing diagram of the touch screen in Embodiment 4 of the present application entering the EMR function mode;

[0111] Fig. 17 is a state diagram of the touch screen entering the EMR function mode in the embodiment 4 of the present application;

[0112] Fig. 18 is another state diagram of the touch screen entering the EMR function mode in the embodiment 4 of the present application;

[0113] Fig. 19 is a timing diagram of the touch screen entering the TSP function mode and the EMR function mode in the embodiment 4 of the present application;

[0114] Fig. 20 is a diagram of an electronic device in the embodiment 5 of the present application;

[0115] Fig. 21 is a diagram of an electronic device in the embodiment 6 of the present application.

[0116] In the figures: 1, touch device; 11, touch chip; P1, common voltage terminal; P2, code signal terminal; P3, control signal terminal; VREF, reference voltage terminal; SW, switch signal terminal; SW1, first switch signal terminal; SW2, second switch signal terminal; IN, input terminal; VEE, negative voltage supply terminal; CLK, clock signal terminal; 12, state switch; 13, code circuit; 14, power supply rail; 2, touch screen; 21, common voltage line; 22, touch unit; 221, function switching switch; 222, touch electrode; 223, control circuit; C1, first capacitor; 2231, switch circuit; TFT1, first control switch; 22311, voltage lifting circuit; TFT2, second control switch; TFT3, third control switch; TFT4, fourth control switch; TFT5, fifth control switch; C2, second capacitor. DETAILED DESCRIPTION

[0117] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0118] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, the embodiments are provided to make the disclosure complete and fully convey the scope of the present application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity throughout the drawings the same reference numbers represent the same elements.

[0119] It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0120] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0121] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0122] For a thorough understanding of the present application, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0123] The electronic device provided by the embodiment of the present application, as shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 13, generally comprises a touch device 1 and a touch screen 2, the touch device 1 is electrically connected with the touch screen 2 through a connecting line to control the touch screen 2 to work. The touch screen 2 can provide a touch and press interface for interacting with a user's finger and an electromagnetic pen. In the press interface, the touch screen 2 can sense the press operation of the user or the electromagnetic pen to perform corresponding press feedback or instruct the electronic device where the touch screen 2 is located to perform corresponding functions, and the press interface can function as a "key" function. In the touch interface, the touch screen 2 can be used to sense the position and movement of the user's finger to perform corresponding touch feedback or instruct the electronic device where the touch screen 2 is located to perform corresponding functions, and the touch interface can function as a "mouse" function. The touch screen 2 can be applied to any kind of human-computer interaction device, such as a notebook computer, a tablet computer, a mobile phone, a smart wearable device, a smart door lock, an Automated Teller Machine (ATM) and the like, and the embodiment of the present disclosure does not limit this.

[0124] The touch device 1 and the touch screen 2 in Embodiments 1-4 are described below, and the touch device 1, especially the touch chip 11, is described in detail.

[0125] Embodiment 1

[0126] The embodiment of the present application provides a touch chip 11, which is an important device of the touch device 1, used for connecting the touch screen 2 and controlling the touch screen 2 to work. As shown in FIG. 1, the touch screen 2 comprises a common voltage line 21 and at least two touch units 22; each touch unit 22 comprises a touch electrode 222, a function switching switch 221 and a control circuit 223; a first end of each touch electrode 222 is connected with the common voltage line 21 through a function switching switch 221; each control circuit 223 is connected with a control end of the function switching switch 221 and a connection node between the function switching switch 221 and the touch electrode 222.

[0127] The touch chip 11 comprises a common voltage end P1, a code signal end P2 and a control signal end P3; the common voltage end P1 is connected with the common voltage line 21; the code signal end P2 is connected with a second end of at least two touch electrodes 222; the control signal end P3 is connected with the control circuit 223, and the control signal end P3 is used for outputting a control signal to the control circuit 223 to make the control circuit 223 control the function switching switch 221 to open or close.

[0128] The common voltage terminal P1 is a port for providing a common voltage to the plurality of touch electrodes 222. The common voltage can be a GND voltage or another voltage close to the GND voltage. As an example, the common voltage terminal P1 of the touch chip 11 is connected to the common voltage line 21 of the touch screen 2 through an external state switch 12. When the state switch 12 is turned on, the touch chip 11 can provide the common voltage to the touch electrodes 222 connected to the common voltage line 21. When the state switch 12 is turned off, the common voltage line 21 is in a suspended state. Alternatively, the common voltage terminal P1 of the touch chip 11 is connected to the common voltage line 21 of the touch screen 2. An internal switch is arranged in the touch chip 11 for connecting the common voltage terminal P1 to other circuits. When the internal switch is turned on, the touch chip 11 can output the common voltage to the common voltage line 21 through the common voltage terminal P1. When the internal switch is turned off, the common voltage terminal P1 is in a suspended state, i.e., the common voltage line 21 is in a suspended state.

[0129] The code signal terminal P2 is a port for providing a code signal to the touch electrodes 222. As an example, the code signal terminal P2 of the touch chip 11 can be connected to the touch electrodes 222 of the touch screen 2 through a code circuit 13. The code circuit 13 can be one or more. Each code circuit 13 can select a positive or negative coding mode for coding. Each code circuit 13 can perform multi-channel output, i.e., can output the code signal to a plurality of touch electrodes 222. Alternatively, a circuit module for outputting the code signal can be integrated in the touch chip 11, so that the touch chip 11 can output the code signal to a plurality of touch electrodes 222.

[0130] The control signal terminal P3 is a port for providing a control signal to the control circuit 223.

[0131] In the example, the touch screen 2 connected with the touch chip 11 includes a common voltage line 21 and at least two touch units 22; each touch unit 22 includes a touch electrode 222, a function switching switch 221 and a control circuit 223; a first end of each touch electrode 222 is connected with the common voltage line 21 through a function switching switch 221, a second end of each touch electrode 222 is connected with a code signal end P2 of the touch chip 11, and one end of the common voltage line 21 is connected with a common voltage end P1 of the touch chip 11; each control circuit 223 is connected with a control signal end P3 of the touch chip 11, a control end of the function switching switch 221, and a connection node between the function switching switch 221 and the touch electrode 222. The function switching switch 221 is a switch arranged between the touch electrode 222 and the common voltage line 21, and is used for switching a TSP function mode and an EMR function mode. When the function switching switch 221 is closed, the connection between the touch electrode 222 of different channels and the common voltage line 21 is disconnected, so that a unidirectional channel is formed between the touch chip 11 and each touch electrode 222, and the touch screen 2 can be controlled to enter the TSP function mode; when the function switching switch 221 is opened, the touch electrode 222 of different channels is connected together, so that the code signal end P2 of the touch chip 11 and at least two touch electrodes 222 on the same common voltage line 21 form a ring-shaped channel, so that the touch chip 11 can control the touch screen 2 to enter the EMR function mode.

[0132] As an example, the common voltage end P1 of the touch chip 11 is connected with the common voltage line 21 through a state switch 12, and the common voltage line 21 is connected through at least two function switching switches 221, and each function switching switch 221 is connected with a first end of a touch electrode 222; when the state switch 12 is turned on, the touch chip 11 can output a common voltage (such as a GND voltage) to at least two function switching switches 221 corresponding to the same common voltage line 21, or when the state switch 12 is turned off, the common voltage line 21 connected with the common voltage end P1 is in a suspended state, so that the function switching switch 221 is disconnected with the touch chip 11.

[0133] As an example, the punch code signal end P2 of the touch chip 11 is connected with the second end of the touch chip 11, and can output a punch code signal to the touch electrode 222 to make the touch electrode 222 perform a punch code operation. The punch code signal can be a first punch code signal for controlling the touch screen 2 to enter a TSP function mode, or can be a second punch code signal for controlling the touch screen 2 to enter an EMR function mode. In the present example, when the touch chip 11 is internally provided with a circuit for implementing a punch code function, the touch chip 11 can be directly connected with the touch electrode 222, for outputting a punch code signal for controlling the touch electrode 222 to perform a punch code operation to the touch electrode 222, so that the touch electrode 222 performs a punch code operation; or when the touch chip 11 is not internally provided with a circuit for implementing a punch code function, the touch chip 11 can be connected with the touch electrode 222 through the punch code circuit 13 shown in FIGS. 1-3, so that the touch chip 11 can control the punch code circuit 13 to output a punch code signal to the touch electrode 222, so that the touch electrode 222 performs a punch code operation.

[0134] As an example, the control signal end P3 of the touch chip 11 is connected with the control end of the function switching switch 221 through the control circuit 223, and the control circuit 223 is also connected with the connection node between the function switching switch 221 and the touch electrode 222. The touch chip 11 can output a control signal to the control circuit 223, so that the control circuit 223 can control the function switching switch 221 to be opened or closed based on the control signal. When the function switching switch 221 is closed, a first punch code signal can be output to the touch electrode 222, so that the touch screen 2 enters a TSP function mode; and when the function switching switch 221 is opened, a second punch code signal can be output to the touch electrode 222, so that the touch screen 2 enters an EMR function mode.

[0135] In the present example, the control signal end P3 of the touch chip 11 controls the function switching switch 221 to be opened or closed through the control circuit 223. Since the control circuit 223 is not only connected with the control end of the function switching switch 221, but also connected with the connection node between the function switching switch 221 and the touch electrode 222, the touch electrode 222 can determine a punch code potential change of the touch electrode 222 during a punch code process based on the punch code signal of the touch chip 11, and adjust the control end potential based on the punch code potential change, so as to guarantee the implementation of the TSP function mode and the EMR function mode.

[0136] Embodiment 2

[0137] In an embodiment, as shown in FIG. 2, each of the control circuits 223 comprises a first capacitor C1 and a switch circuit 2231; one end of the first capacitor C1 is connected to the control end of the function switch 221, and the other end of the first capacitor C1 is connected to the connection node between the function switch 221 and the touch electrode 222; the second end of the switch circuit 2231 is connected to the control end of the function switch 221;

[0138] The control signal end P3 comprises a reference voltage end VREF and a switch signal end SW, the reference voltage end VREF is connected to the first end of the switch circuit 2231, and the switch signal end SW is connected to the third end of the switch circuit 2231;

[0139] The switch signal end SW outputs a control signal to the switch circuit 2231 to make the switch circuit 2231 open or close, and the reference voltage end VREF outputs a reference voltage to the switch circuit 2231, based on which the function switch 221 is controlled to open or close.

[0140] In this example, each of the control circuits 223 in the touch screen 2 comprises a first capacitor C1 and a switch circuit 2231. The first capacitor C1 is a capacitor used to form a bootstrap circuit with the function switch 221. One end of the first capacitor C1 is connected to the control end of the function switch 221, and the other end of the first capacitor C1 is connected to the connection node between the function switch 221 and the touch electrode 222. When the function switch 221 is a TFT, the first capacitor C1 is arranged between the gate and the source of the function switch 221. The first end of the switch circuit 2231 is connected to the reference voltage end VREF of the touch chip 11, the second end of the switch circuit 2231 is connected to the control end of the function switch 221, and the third end of the switch circuit 2231 is connected to the switch signal end SW of the touch chip 11.

[0141] As an example, the reference voltage end VREF of the touch chip 11 is connected to the first end of the switch circuit 2231, and the reference voltage can be output to the first end of the switch circuit 2231; the second end of the switch circuit 2231 is connected to the control end of the function switching switch 221; the switch signal end SW of the touch chip 11 is connected to the third end of the switch circuit 2231, and the control signal can be output to the third end of the switch circuit 2231 to control the switch circuit 2231 to open or close, so as to determine whether the reference voltage output by the touch chip 11 is transmitted to the control end of the function switching switch 221, so as to control the function switching switch 221 to open or close based on the reference voltage. In the example, when the reference voltage output by the touch chip 11 makes the voltage Vgs between the gate and the source of the function switching switch 221 less than the conduction threshold |Vthp|, the function switching switch 221 is closed; otherwise, when the reference voltage output by the touch chip 11 makes the voltage Vgs between the gate and the source of the function switching switch 221 not less than the conduction threshold |Vthp|, the function switching switch 221 is closed. The conduction threshold |Vthp| is a threshold value for controlling the function switching switch 221 to be turned on, and the specific value is determined by the actual screen process, for example, the conduction threshold |Vthp| can be set to 2.7V or other values. It can be understood that since the reference voltage output by the touch chip 11 needs to control the function switching switch 221 to open or close, it is related to the function switching switch 221. For example, when the function switching switch 221 is TFT, the voltage in the conduction state is in the range of -5V to 5V, and when it is required to enter the TSP function mode, in order to keep it closed, the reference voltage can be set to be consistent with the code waveform of the touch electrode 222, which is close to the GND voltage; when it is required to enter the EMR function mode, in order to make it open, it can be set to -2V.

[0142] In the example, one end of the first capacitor C1 is connected to the control end of the function switch 221, and the other end of the first capacitor C1 is connected to the connection node between the function switch 221 and the touch electrode 222, so that the first capacitor C1 cooperates with the function switch 221 to form a bootstrap circuit. The bootstrap circuit can make the control end potential of the function switch 221 follow the coding potential of the touch electrode 222 during the coding process based on the coding signal of the touch chip 11, so as to ensure the implementation of the TSP function mode and the EMR function mode. For example, when the touch chip 11 controls the touch screen 2 to enter the TSP function mode, the function switch 221 can be controlled to be closed, so that it can enter the coding stage of the TSP function mode, and the touch electrode 222 can code based on the coding signal of the touch chip 11. At this time, the control circuit 223 cooperates with the function switch 221 to control the gate voltage of the function switch 221 to follow the coding potential of the touch electrode 222, so that the off-state current of the function switch 221 is small, and the leakage current of the function switch 221 does not affect the TSP function mode of the touch screen 2.

[0143] As the function switch for distinguishing the TSP function mode and the EMR function mode, the size of the on-resistance of the function switch itself will seriously affect the total resistance between the EMR channels, so a function switch with a larger size needs to be considered to reduce the on-resistance Rdson. However, when the size of the function switch is large, the corresponding off-state current is large, so that when the function switch enters the TSP function mode, the signal of the adjacent channel will introduce leakage current and affect the normal work, and even there is a risk of failure of the TSP function mode. Therefore, how to reduce the off-state current of the function switch has become a problem to be solved.

[0144] In an embodiment, as shown in FIG. 2, the common voltage end P1 is connected to the common voltage line 21 through the state switch 12.

[0145] The reference voltage includes a first reference voltage for controlling the function switch 221 to be closed;

[0146] The switch signal end SW is used to output a first control signal to the switch circuit 2231 to make the switch circuit 2231 open, and the reference voltage end VREF is used to output the first reference voltage to the switch circuit 2231 to control the function switch 221 to be closed and initialize the control end potential of the function switch 221;

[0147] The switch signal terminal SW is configured to output a second control signal to the switch circuit 2231, so that the switch circuit 2231 is closed, the function switch 221 is maintained in the closed state, and the control terminal of the function switch 221 follows the code signal potential of the touch electrode 222.

[0148] When the state switch 12 is in the on state, the common voltage terminal P1 is configured to output a common voltage to the common voltage line 21, and the code signal terminal P2 is configured to output a first code signal to the touch electrode 222, so that the touch screen 2 enters a TSP function mode.

[0149] The first control signal is a control signal for controlling the switch circuit 2231 to be open. The second control signal is a control signal for controlling the switch circuit 2231 to be closed. The voltage range of the first control signal and the second control signal depends on the switch circuit 2231 to be controlled, which can be a control signal of -5V to 5V. The control signal can be, but is not limited to, a square wave signal or a sine wave signal. In this example, either of the first control signal and the second control signal is a low-level signal, and the other is a high-level signal. The first control switch TFT1 can be a PTFT, which is turned on based on a low-level signal and turned off based on a high-level signal. Alternatively, the first control switch TFT1 can also be an NTFT, which is turned on based on a high-level signal and turned off based on a low-level signal.

[0150] The first reference voltage is a reference voltage output by the touch chip 11 for controlling the function switch 221 to be closed, and is a reference voltage that can initialize the control terminal potential of the function switch 221. The value range of the first reference voltage depends on the function switch 221 to be controlled. When the function switch 221 is a PTFT, in order to make the PTFT closed, the first reference voltage can be determined as 0V. The first code signal is a code signal output to the touch electrode 222 when the touch screen 2 enters the TSP function mode. The common voltage is a voltage output by the touch chip 11 to the common voltage line 21 for providing to all function switches 221. For example, the common voltage can be a GND voltage or a voltage close to this value, for example, it can be set to 0V.

[0151] The TSP function mode refers to a capacitive touch mode, that is, when a user touches the screen with a finger or other objects, the capacitance of the touch point will change, and the touch position is determined by measuring the change of the capacitance.

[0152] In an example, when the function switch 221 is a TFT (specifically a PTFT), the control process of the touch chip 11 for controlling the touch screen 2 to enter the TSP function mode is as follows:

[0153] (1) The switch signal end SW of the touch chip 11 can output a first control signal to control the switch circuit 2231 to open, and the reference voltage end VREF of the touch chip 11 can output a first reference voltage. When the switch circuit 2231 is open, the first reference voltage can be transmitted to the gate of the function switching switch 221 to control the function switching switch 221 to close. In the example, the first reference voltage transmitted to the gate of the function switching switch 221 can initialize the gate potential of the function switching switch 221, that is, provide an initial gate voltage for the function switching switch 221; at the same time, the corresponding touch electrode 222 also has an initial voltage. At this time, the initial voltage difference between the gate and the source of the function switching switch 221 can be determined, which can ensure that the voltage Vgs between the gate and the source of the function switching switch 221 is less than the conduction threshold |Vthp|, so that the function switching switch 221 is in a closed state, and the voltage Vds between the drain and the source of the function switching switch 221 is also close to 0, so that the off-state current of the function switching switch 221 is very small. The initial voltage of the touch electrode 222 can be a fixed voltage close to the middle voltage of the code striking waveform, for example, it can be a GND voltage. The initial voltage difference is a fixed value determined based on the first reference voltage and the initial voltage of the touch electrode 222.

[0154] (2) The switch signal end SW of the touch chip 11 can output a second control signal to control the switch circuit 2231 to close, so that the gate of the function switching switch 221 is in a suspended state. The bootstrap effect of the capacitor unit formed by the first capacitor C1 and the parasitic capacitor Cgs of the function switching switch 221 itself can maintain the gate potential of the function switching switch 221, so that when the TSP function mode enters the code striking stage, the gate potential of the function switching switch 221 can follow the code striking potential change, and the voltage Vgs between the gate and the source of the function switching switch 221 is less than the conduction threshold |Vthp|, so that the function switching switch 221 is in a closed state, so that the off-state current of the function switching switch 221 is small, so as to avoid the influence of the leakage current of the function switching switch 221 on the implementation of the TSP function mode.

[0155] (3) When the function switch 221 is in the off state and the state switch 12 is in the on state, the common voltage terminal P1 is used to output a common voltage to the common voltage line 21, and the code signal terminal P2 is used to output a first code signal to the touch electrode 222, so that the touch screen 2 enters the TSP function mode. In this process, the voltage Vgs of the function switch 221 changes with the code potential, so that the voltage Vds of the function switch 221 changes, but the off-state current formed by the voltage Vds is small, so as to avoid the influence of the leakage current of the function switch 221 on the implementation of the TSP function mode. In this example, the common voltage output by the touch chip 11 can be a GND voltage or other voltage close to the GND voltage, so as to keep the touch electrode 222 in the off state and ensure that the off-state current is small.

[0156] In an embodiment, as shown in FIG. 2, the reference voltage includes a second reference voltage used to control the switch circuit 2231 to be off;

[0157] When the switch signal terminal SW is used to output a second control signal to the switch circuit 2231, the reference voltage terminal VREF outputs the second reference voltage to the switch circuit 2231, so that the switch circuit 2231 maintains the off state.

[0158] The second reference voltage is a reference voltage output by the touch chip 11 to maintain the switch circuit 2231 in the off state, and the voltage value depends on the switch circuit 2231 to be controlled. For example, when the switch circuit 2231 is a PTFT, the second reference voltage can be a GND voltage or a voltage close to the value, so that the PTFT is off.

[0159] As an example, the switch signal terminal SW of the touch chip 11 outputs a second control signal to the third terminal of the switch circuit 2231, so that the switch circuit 2231 is off, and at the same time, the reference voltage terminal VREF of the touch chip 11 outputs a second reference voltage to the first terminal of the switch circuit 2231, so as to adjust the voltage of the first terminal of the switch circuit 2231 to a GND voltage or a fixed voltage close to the value, so as to avoid the output signal of other circuits coupled to the first terminal of the switch circuit 2231 changing the voltage of the first terminal of the switch circuit 2231, so that the switch circuit 2231 cannot maintain the off state and affect the implementation of the TSP function mode.

[0160] In an embodiment, as shown in FIG. 2, the code signal terminal P2 is used to output a first code signal to at least two touch electrodes 222 at the same time.

[0161] As an example, since the function switch 221 is closed, the touch chip 11 forms a one-way channel with the plurality of touch electrodes 222, so that when the function switch 221 is in the closed state, the touch chip 11 outputs the first code signal to at least two touch electrodes 222 corresponding to the same common voltage line 21 through the code signal end P2 of the touch chip 11, so that the code current flows through the at least two touch electrodes 222 corresponding to the same common voltage line 21, so that the touch screen 2 enters the TSP function mode (the timing is shown in FIGS. 5, 12, 14 and 19), so as to guarantee the code efficiency of the TSP function mode. During the coding process, due to the bootstrap effect of the capacitor unit formed between the first capacitor C1 and the parasitic capacitor Cgs of the function switch 221, the gate potential of the function switch 221 can be controlled to follow the code potential, so that the off-state current of the function switch 221 is small.

[0162] In an embodiment, as shown in FIGS. 2 and 3, the common voltage end P1 is connected to the common voltage line through the state switch 12;

[0163] The reference voltage includes a third reference voltage for controlling the function switch 221 to be opened;

[0164] The switch signal end SW is used to output a first control signal to the switch circuit 2231 to make the switch circuit 2231 open, and the reference voltage end VREF is used to output the third reference voltage to the switch circuit 2231 to control the function switch 221 to be opened;

[0165] When the state switch 12 is in the open state, the code signal end P2 is used to output a second code signal to the touch electrode 222, so that the touch screen 2 enters the EMR function mode.

[0166] The third reference voltage is a reference voltage output by the touch chip 11 for controlling the function switch 221 to be opened. The value range of the third reference voltage depends on the function switch 221 to be controlled. When the function switch 221 is a PTFT, in order to make the PTFT open, the third reference voltage can be determined as -2V. The second code signal is a code signal output to the touch electrode 222 when the touch screen 2 enters the EMR function mode. The EMR function mode is an electromagnetic touch mode, that is, when the user operates the electromagnetic pen to touch the screen, the touch screen 2 can sense the corresponding electromagnetic signal to determine the touch position.

[0167] In some possible implementation manners, when the functional switch 221 is a TFT (specifically, a PTFT), the switch signal end SW of the touch chip 11 can output a first control signal to control the switch circuit 2231 to be open, and the reference voltage end VREF of the touch chip 11 can output a third reference voltage, which can be transmitted to the gate of the functional switch 221 when the switch circuit 2231 is open, so that the voltage between the gate and the source of the functional switch 221 is greater than or equal to the on threshold |Vthp|, and the third reference voltage can control the functional switch 221 to be open. In the state that the state switch 12 is in the off state (for example, the HiZ state in FIGS. 7 and 18), that is, the control of the common voltage line 21 is in the suspended state, the punch code signal end P2 of the touch chip 11 forms a ring-shaped channel with at least two touch electrodes 222 on the same common voltage line 21, at this time, the punch code signal end P2 of the touch chip 11 outputs a second punch code signal to the touch electrodes 222, so that the touch screen 2 enters the EMR function mode. In the example, the state switch 12 is arranged between the common voltage end P1 and the common voltage line 21, and the state switch 12 can be connected with the touch chip 11 and be turned on or turned off based on the control signal output by the touch chip 11, or can be connected with other control devices and be controlled by the other control devices.

[0168] In an embodiment, as shown in FIGS. 7, 8, 15 and 18, the common voltage line 21 includes a first common voltage line 221 connected with at least three touch electrodes 222.

[0169] The punch code signal end P2 is configured to output a second punch code signal to the at least three touch electrodes 222 corresponding to the same first common voltage line 21 one by one.

[0170] As an example, the common voltage line 21 connected with the common voltage terminal P1 of the touch chip 11 can be a first common voltage line 211, and the first common voltage line 211 is the common voltage line 21 connected with at least three touch electrodes 222. In this example, the common voltage terminal P1 of the touch chip 11 is connected with one end of the first common voltage line 211, and the first common voltage line 211 is further connected with at least three function switching switches 221, each of which is connected with a touch electrode 222. When the state switch 12 is in the off state, i.e., the first common voltage line 211 is in the suspended state, the first common voltage line 211 cooperates with the at least three touch electrodes 222 to form a loop structure similar to a comb structure. The code signal terminal P2 of the touch chip 11 is further connected with the second end of the at least three touch electrodes 222 corresponding to the same first common voltage line 211. The code signal terminal P2 of the touch chip 11 can output the second code signal to the at least three touch electrodes 222 corresponding to the same first common voltage line 211 one by one (the timing thereof is shown in FIGS. 9, 12, 16 and 19), so that the code current flows through the at least three touch electrodes 222 one by one, to ensure that only one touch electrode 222 codes based on the second code signal at the same time, to avoid signal crosstalk. This way requires fewer common voltage lines 21, which helps to save costs and occupied area.

[0171] In an embodiment, as shown in FIGS. 10 and 11, the common voltage line 21 includes a second common voltage line 212 connected with two touch electrodes 222.

[0172] The code signal terminal P2 is configured to output the second code signal to the two touch electrodes 222 corresponding to the same second common voltage line 212 at the same time.

[0173] As an example, the common voltage line 21 connected with the common voltage terminal P1 of the touch chip 11 can be a second common voltage line 212, and the second common voltage line 212 is the common voltage line 21 connected with two touch electrodes 222. In this example, the common voltage terminal P1 of the touch chip 11 is connected with one end of the second common voltage line 212, and the second common voltage line 212 is further connected with two function switching switches 221, each of which is connected with a touch electrode 222. When the state switch 12 is in the off state, i.e., the first common voltage line 211 is in the suspended state, the first common voltage line 211 corresponding to the two touch electrodes 222 and the two code signal terminals P2 of the touch chip 11 form a ring-shaped channel, so that the touch chip 11 can output the second code signal to the two touch electrodes 222 corresponding to the same second common voltage line 212 at the same time, so that the code current flows through the two touch electrodes 222 at the same time. This way can effectively shorten the coding time and help improve the coding efficiency.

[0174] Embodiment 3

[0175] In an embodiment, as shown in FIGS. 3-12, the switch circuit 2231 includes a first control switch TFT1, a second end of the first control switch TFT1 being connected to the control end of the function switching switch 221.

[0176] The reference voltage end VREF is connected to a first end of the first control switch TFT1, and the switch signal end SW is connected to a control end of the first control switch TFT1.

[0177] The switch signal end SW outputs a first control signal to the first control switch TFT1 to open the first control switch TFT1, or outputs a second control signal to the first control switch TFT1 to close the first control switch TFT1.

[0178] As an example, the switch circuit 2231 includes a first control switch TFT1, the reference voltage end VREF is used to connect a first end of the first control switch TFT1 and output a reference voltage to the first control switch TFT1; the switch signal end SW is used to connect a control end of the first control switch TFT1 and output a control signal to the first control switch TFT1, so as to control the first control switch TFT1 to open or close through the control signal output by the switch signal end SW and the reference voltage output by the reference voltage end VREF.

[0179] In this example, the first control switch TFT1 is arranged between the reference voltage end VREF of the touch chip 11 and the control end of the function switching switch 221, the control end of the first control switch TFT1 being connected to the switch signal end SW of the touch chip 11 and being openable based on a first control signal output by the touch chip 11 and closable based on a second control signal output by the touch chip 11. In this example, either one of the first control signal and the second control signal is a low-level signal, and the other is a high-level signal. The first control switch TFT1 can be a PTFT, which is openable based on a low-level signal and closable based on a high-level signal; or the first control switch TFT1 can also be an NTFT, which is conductive based on a high-level signal and is cut off based on a low-level signal.

[0180] As shown in FIG. 8, when the first control switch TFT1 and the function switching switch 221 are TFTs, the drain of the first control switch TFT1 is connected with the reference voltage terminal VREF of the touch chip 11, and can receive the reference voltage output by the touch chip 11; the source of the first control switch TFT1 is connected with the gate of the function switching switch 221; the gate of the first control switch TFT1 is connected with the switch signal terminal SW of the touch chip 11, and can be opened or closed according to different level signals output by the switch signal terminal SW of the touch chip 11, so as to determine whether the reference voltage output by the touch chip 11 is transmitted to the gate of the function switching switch 221. In the example, when the first control signal is output by the switch signal terminal SW of the touch chip 11, the first control switch TFT1 can be controlled to be opened, so that the first reference voltage output by the reference voltage terminal VREF is transmitted to the gate of the function switching switch 221, the function switching switch 221 is controlled to be in the closed state, and the gate potential of the function switching switch 221 is initialized; when the second control signal is output by the switch signal terminal SW of the touch chip 11, the first control switch TFT1 can be controlled to be closed, so that the function switching switch 221 remains in the closed state, and when the TSP function mode enters the code input stage, the first capacitor C1 and the function switching switch 221 cooperate to form a bootstrap circuit, so that the gate potential of the function switching switch 221 follows the code input potential of the touch electrode 222, so as to make the off-state current of the function switching switch 221 small, so as to avoid the influence of the leakage current of the function switching switch 221 on the implementation of the TSP function mode.

[0181] In the example, the control circuit 223 includes a switching circuit 2231 and the first capacitor C1, and the two ends of the first capacitor C1 are connected with the gate and the source of the function switching switch 221 respectively, so that the first capacitor C1 cooperates with the function switching switch 221 to form a bootstrap circuit which can realize bootstrap effect. The first end of the first control switch TFT1 is connected with the reference voltage terminal VREF of the touch chip 11, and can receive the reference voltage VREF output by the touch chip 11; the second end of the first control switch TFT1 is connected with the gate of the function switching switch 221; the switch signal terminal SW of the touch chip 11 is connected with the control end of the first control switch TFT1, and different level signals can be output to the control end of the first control switch TFT1, so as to control the first control switch TFT1 to be opened or closed, so as to determine whether the reference voltage VREF provided by the touch chip 11 can be transmitted to the function switching switch 221, and the function switching switch 221 is controlled to be opened or closed based on the reference voltage VREF. Since the first capacitor C1 and the function switching switch 221 cooperate to form a bootstrap circuit, the gate potential of the function switching switch 221 follows the code input potential of the touch electrode 222, so as to make the off-state current of the function switching switch 221 small, so as to avoid the influence of the leakage current of the function switching switch 221 on the implementation of the TSP function mode.

[0182] Embodiment 4

[0183] In an embodiment, as shown in FIGS. 13-19, the switch circuit 2231 further comprises a voltage lifting circuit 22311 connected to the connection node between the second end of the first control switch TFT1 and the control end of the function switching switch 221;

[0184] The control signal end P3 is further connected to the voltage lifting circuit 22311, and outputs a control signal in a second voltage range to the voltage lifting circuit 22311, so that the voltage lifting circuit 22311 lifts the control signal in the second voltage range and converts it into a control signal in a first voltage range to control the function switching switch 222 to open or close.

[0185] The second voltage range is a voltage range that cannot directly control the control switch in the function switching switch 222 to open or close, which is determined based on the performance of the touch chip 11 itself. The first voltage range is a voltage range that can directly control the control switch in the function switching switch 222 to open or close, which is determined based on the performance of the touch chip 11 itself.

[0186] As an example, when the function switching switch 222 is a TFT, the first voltage range for controlling the TFT to open or close is a higher voltage range (e.g., 3V-8V). If the touch chip 11 is a touch chip 11 prepared based on a low-voltage process, the touch chip 11 outputs a control signal in a second voltage range. In this case, a voltage lifting circuit 22311 needs to be provided on the touch screen 2, which is provided between the control signal end P3 of the touch chip 11 and the control end of the function switching switch 221, and can lift the control signal in the second voltage range output by the common voltage end P1 and convert it into a control signal in the first voltage range, so that the function switching switch 222 opens or closes. In this example, because the voltage lifting circuit 22311 is provided on the touch screen 2 to lift the signal, the voltage range output by the touch chip 11 can be appropriately reduced, and a touch chip 11 manufactured by a conventional low-voltage process can be used to control the touch screen 2, without the need to select a touch chip 11 manufactured by a particularly high-voltage process, which helps to reduce the cost of the touch chip 11.

[0187] In an embodiment, as shown in FIG. 13, the voltage lifting circuit 22311 includes a second control switch TFT2, a third control switch TFT3, a fourth control switch TFT4, a fifth control switch TFT5, and a second capacitor C2; the second control switch TFT2, the third control switch TFT3, and the fourth control switch TFT4 are connected in series in sequence, and the fourth control switch TFT4 is connected to the control end of the function switching switch 221; the second end of the fifth control switch TFT5 is connected to the connection node between the third control switch TFT3 and the fourth control switch TFT4, and the control end of the fifth control switch TFT5 is connected to the control end of the fourth control switch TFT4; and the two ends of the second capacitor C2 are respectively connected to the second end of the fifth control switch TFT5 and the control end of the fifth control switch TFT5.

[0188] The switch signal end SW includes a first switch signal end SW1 and a second switch signal end SW2; and the control signal end P3 further includes an input end IN, a negative voltage supply end VEE, and a clock signal end CLK.

[0189] The first switch signal end SW1 is configured to be connected to the control end of the first control switch TFT1 and output a first switch signal to the first control switch TFT1; the second switch signal end SW2 is configured to be connected to the control end of the second control switch TFT2 and output a second switch signal to the second control switch TFT2; the input end IN is configured to be connected to the first end of the second control switch TFT2 and output a first voltage to the second control switch TFT2; the negative voltage supply end VEE is configured to be connected to the control end of the third control switch TFT3 and output a VEE voltage to the third control switch TFT3; and the clock signal end CLK is configured to be connected to the first end of the fifth control switch TFT5 and output a second voltage to the fifth control switch TFT5; and the voltage lifting circuit 22311 is controlled to perform voltage lifting based on the first switch signal, the second switch signal, the first voltage, the VEE voltage, and the second voltage.

[0190] The first switch signal is a switch signal for controlling the operation of the first control switch TFT1, which can be a high-level signal or a low-level signal. The second switch signal is a switch signal for controlling the operation of the second control switch TFT2, which can be a high-level signal or a low-level signal. The first voltage is a voltage output from the input terminal IN to the second control switch TFT2, which can be adjusted according to actual conditions, for example, can be a VDD voltage or a VEE voltage. The negative voltage supply terminal VEE outputs a VEE voltage to the third control switch TFT3, so that the third control switch TFT3 is in a normal open state and is only used as a reverse limiting current limiting tube. The second voltage is a voltage output from the clock signal terminal CLK to the fifth control switch TFT5, which can be adjusted according to actual conditions, for example, can be a GND voltage or a VEE voltage. The VDD voltage herein is a positive power voltage, that is, the working voltage of the touch chip 11, which can be set to a value range of +3.3V to 5V; the VEE voltage is a negative power voltage, which can be set to -5V, -8V or other negative power voltage; and the GND voltage is a voltage of a zero potential reference point, which has a value of 0V.

[0191] As an example, the switch signal end SW includes a first switch signal end SW1 and a second switch signal end SW2, the first switch signal end SW1 is used for connecting a control end of a first control switch TFT1; the control signal end P3 further includes an input end IN, a negative voltage supply end VEE and a clock signal end CLK; the first switch signal end SW1 of the touch chip 11 is connected to the first control switch TFT1, and the voltage lifting circuit 22311 includes a second control switch TFT2, a third control switch TFT3, a fourth control switch TFT4, a fifth control switch TFT5 and a second capacitor C2; the second control switch TFT2, the third control switch TFT3 and the fourth control switch TFT4 are connected in series, the fourth control switch TFT4 is connected to a control end of the function switching switch PTFT1; a second end of the fifth control switch TFT5 is connected to a connection node between the third control switch TFT3 and the fourth control switch TFT4; when two ends of the second capacitor C2 are connected to the second end of the fifth control switch TFT5 and a control end of the fifth control switch TFT5 respectively, the input end IN is used for connecting a first end of the second control switch TFT2, the second switch signal end SW2 is used for connecting a control end of the second control switch TFT2; the negative voltage supply end VEE is used for connecting a control end of the third control switch TFT3; and the clock signal end CLK is used for connecting a first end of the fifth control switch TFT5. In the example, the first control switch TFT1 can be controlled to open or close according to a first switch signal output by the first switch signal end SW1, the second control switch TFT2 can be controlled to open or close according to a second switch signal output by the second switch signal end SW2, in combination with a reference voltage output by the reference voltage end VREF to the first control switch TFT1, a first voltage output by the input end IN to the second control switch TFT2, a VEE voltage output by the negative voltage supply end VEE to the third control switch TFT3, and a second voltage output by the clock signal end CLK to the fifth control switch TFT4, the voltage differences between two ends of each control switch are compared to control the third control switch TFT3, the fourth control switch TFT4 and the fifth control switch TFT5 to open or close, so that the voltage lifting purpose can be achieved while the third control switch TFT3, the fourth control switch TFT4 and the fifth control switch TFT5 enter the TSP function mode and the EMR function mode switching.

[0192] In an embodiment, the first switch signal end SW1 is used for outputting a first control signal to the first control switch TFT1 to make the first control switch TFT1 open, and the reference voltage end VREF is used for outputting a first reference voltage to the first control switch TFT1 to make the function switching switch 221 close.

[0193] The second switch signal end SW2 is used for outputting a first control signal to the second control switch TFT2, so that the second control switch TFT2 is opened, the input end IN is used for outputting a VDD voltage to the second control switch TFT2, and the clock signal end CLK is used for outputting a GND voltage to the fourth control switch TFT4, so that the fourth control switch TFT4 and the fifth control switch TFT5 are closed.

[0194] As an example, as shown in FIG. 14 and FIG. 15, the touch chip 11 sequentially performs the following operations to control the touch screen 2 to enter the TSP function mode:

[0195] The first switch signal end SW1 outputs a first control signal to the first control switch TFT1, so that the first control switch TFT1 is opened, and the reference voltage end VREF outputs a reference voltage to the first control switch TFT1, so that the reference voltage output by the reference voltage end VREF is transmitted to a gate node (i.e. N1 node) of the function switching switch PTFT1, so that the gate potential of the function switching switch PTFT1 is adjusted from the initial GND voltage to the reference voltage.

[0196] The second switch signal end SW2 outputs a first control signal to the second control switch TFT2, so that the second control switch TFT2 is opened based on the first control signal, so that the VDD voltage output by the input end IN is transmitted to the N3 node, and the negative voltage supply end VEE outputs a VEE voltage to the third control switch TFT3, so that the third control switch TFT3 is in a normally open state, at this time, the VDD voltage output by the input end IN can be transmitted to the N2 node, when the VDD voltage is greater than the reference voltage, the potential of the N2 node is higher than that of the N1 node, so that the fourth control switch TFT4 is in a closed state in the entire TSP working interval, and the gate potential of the function switching switch PTFT can be initialized based on the reference voltage. At the same time during this period, the N1 node is at a high potential, the second control switch TFT2 is closed based on the second control signal output by the second switch signal end SW2, the N2 node is at a high potential, the clock signal end CLK is used for outputting a GND voltage to the fourth control switch TFT4, so that the fifth control switch TFT5 is closed, so that the off-state current of the fifth control switch TFT5 can be as small as possible, and the static current consumption of the entire system is reduced.

[0197] In the example, when it is required to control the touch screen 2 to enter the TSP function mode, the first control switch TFT1 is controlled to open based on the first control signal output by the first switch signal end SW1, so as to transmit the reference voltage output by the reference voltage end VREF to the N1 node, and the initialization of the gate potential of the function switch PTFT1 is completed. The other circuits in the circuit remain in the closed state after the initialization is completed. The process of the code input stage in the TSP function mode is the same as that in the above-mentioned embodiment. To avoid repetition, the details are not described herein.

[0198] In an embodiment, the first switch signal end SW1 is configured to output a first control signal to the first control switch TFT1, so as to open the first control switch TFT1, and the reference voltage end VREF is configured to output a VEE voltage to the first control switch TFT1, so as to open the function switch 221.

[0199] The second switch signal end SW2 is configured to output a first control signal to the second control switch TFT2, so as to open the second control switch TFT2, the input end IN is configured to output a VEE voltage to the second control switch TFT2, the clock signal end CLK is configured to output a GND voltage to the fifth control switch TFT5, so as to close the fourth control switch TFT4, and the fifth control switch TFT5 is opened.

[0200] The first switch signal end SW1 is configured to output a second control signal to the first control switch TFT1, so as to close the first control switch TFT1, the second switch signal end SW2 is configured to output a second control signal to the second control switch TFT2, so as to close the second control switch TFT2, and the clock signal end CLK is configured to output a VEE voltage to the fifth control switch TFT5, so as to open the fourth control switch TFT4 and the fifth control switch TFT5.

[0201] As an example, as shown in FIGS. 16 to 19, the touch chip 11 sequentially performs the following three state operations to control the touch screen 2 to enter the EMR function mode:

[0202] State 1: the first switch signal end SW1 is used to output a first control signal to the first control switch TFT1, so that the first control switch TFT1 is opened, and the reference voltage end VREF is used to output a VEE voltage to the first control switch TFT1, so that the function switch 221 is opened. For example, when the first control switch TFT1 is a unipolar PTFT, the unipolar PTFT is opened at the lowest potential, which will lose one |Vthp|. Therefore, the first control switch TFT1 pulls the first end potential of the first control switch TFT1 to the low level VEE based on the reference voltage output by the reference voltage end VREF, and the first control switch TFT1 is opened based on the first control signal output by the first switch signal end SW1, so that the N1 node keeps VEE+|Vthp|.

[0203] State 2: the second switch signal end SW2 is used to output a first control signal to the second control switch TFT2, so that the second control switch TFT2 is opened; the input end IN outputs a VEE voltage to the second control switch TFT2, so that the low level VEE received by the first end of the second control switch TFT2 is adjusted through the third control switch TFT3, so that the potential of the N2 node is adjusted to VEE+2x|Vthp|. Based on this condition, the fourth control switch TFT4 is a diode Connect mode tube, and Vsg<|Vthp|, so that the fourth control switch TFT4 will not be opened, and the potentials of the N1 node and the N2 node are kept respectively. At the same time, the first end of the fifth control switch TFT5 receives the GND voltage output by the clock signal end CLK of the touch chip 11, and the N2 node potential controls the fifth control switch TFT5 to be opened.

[0204] State 3: the first switch signal end SW1 is used to output a second control signal to the first control switch TFT1, so as to make the first control switch TFT1 close, and the second switch signal end SW2 is used to output a second control signal to the second control switch TFT2, that is, the control signals of the first switch signal end SW1 and the second switch signal end SW2 are pulled high, so that the first control switch TFT1 and the second control switch TFT2 are closed. The first end of the fifth control switch TFF5 is based on the VEE voltage output by the clock signal end CLK, so that the first end of the fifth control switch TFF5 is based on the GND level and is changed to the VEE level. Since the fifth control switch TFT5 and the second capacitor C2 form a bootstrap structure, the potential of the N4 node is pulled to the VEE potential, and the N2 node is also changed from VEE+2x|Vthp| to 2xVEE+2x|Vthp|. At this time, since the fourth control switch TFT4 satisfies Vsg>|Vthp|, the potential of the N1 node is adjusted to 2xVEE+3x|Vthp|, and based on this, the potential of the N1 node can be less than the value of the VEE voltage through the above structure, that is, the demand of a larger driving voltage range can be met.

[0205] The process used by the conventional touch chip 11 is based on the VDD-VEE range, generally a low-voltage process of +5V to -5V, and the high and low voltage range of the conventional PTFT is +8V to -8V. Therefore, through the above circuit with a bootstrap, the control level of the N1 node can be adjusted to below the VEE level, so as to better control the on-resistance Rdson of the PTFT1. Since the Vds of the PTFT1 is fixed, and the lower the Vg is, the smaller the Rdson is. In this example, since the subsequent TX1 adopts a sine wave signal in the EMR coding phase, a part of small fluctuations will also be coupled to the N1 node through the first capacitor C1, and a part of the jitter will also be filtered through the fourth control switch TFT4, so that the disturbance of the N2 node is smaller. As shown in FIG. 19, after the touch chip 11 controls the touch screen 2 to complete a TSP function mode and / or an EMR function mode, the touch chip 11 needs to control the touch screen 2 to complete an initialization operation, that is, the reference voltage output by the reference voltage end VERF is used to initialize the potential (that is, the gate potential) of the control end of the function switching switch 221, so as to ensure the accuracy of the control process and avoid the influence of the cumulative error of multiple operations on the control accuracy.

[0206] In the example, when it is needed to control the touch screen 2 to enter the EMR function mode, the potentials of the N1 node and the N2 node are both set to be low, then the potential of the N2 node is pulled to be lower by the bootstrap architecture formed by the fifth control switch TFT5 and the second capacitor C2 through the conversion of the potential of the clock signal end CLK from the GND voltage to the VEE voltage, and the lower potential is transmitted to the N1 node through the fourth control switch TFT4, so as to achieve the purpose of adjusting the N1 node to a lower potential than the VEE, and thus the purpose of achieving a larger driving voltage range control by using the standard TP-IC process is realized.

[0207] In an embodiment, the touch chip is configured to output a control signal in a first voltage range to the control circuit 223, so that the control circuit 223 controls the function switch 222 to be opened or closed.

[0208] The first voltage range is a voltage range that can directly control the control switch in the function switch 222 to be opened or closed, and is determined based on the performance of the touch chip 11 itself.

[0209] For example, when the function switch 222 is a TFT, the corresponding first voltage range is a higher voltage range (such as 3V-8V), and if the touch chip 11 is prepared based on a high-voltage process, the touch chip 11 can directly output a control signal in the first voltage range to the control circuit 223, so that the control circuit 223 controls the function switch 222 to be opened or closed.

[0210] The embodiment of the application provides a touch device 1, as shown in FIG. 2 and FIG. 3, which comprises the touch chip 11 and the state switch 12 in the above embodiment.

[0211] One end of the state switch is connected to the common voltage end of the touch chip, and the other end of the state switch is used to connect the common voltage line of the touch screen.

[0212] As an example, the touch device 1 comprises the touch chip 11 and the state switch 12, the state switch 12 is arranged at the common voltage end P1 of the touch chip 11 and the common voltage line 21 of the touch screen 2, the control end of the state switch 12 can be connected to the touch chip 11 or other control devices, when it is needed to control the touch screen 2 to enter the TSP function mode, the state switch 12 is controlled to be turned on, and the touch chip 11 can output the common voltage to the common voltage line 21 through the common voltage end P1, so that the function switch 211 is maintained in the closed state; on the contrary, when it is needed to control the touch screen 2 to enter the EMR function mode, the state switch 12 is controlled to be turned off, so that the common voltage line 21 is in a suspended state, and the touch screen 2 enters the EMR function mode.

[0213] In an embodiment, as shown in FIGS. 1-3, the touch device 1 further comprises a code circuit 13.

[0214] One end of the code circuit 13 is connected with the code signal end P2 of the touch chip 11, and the other end of the code circuit 13 is used for connecting the touch electrode 222 of the touch screen 2.

[0215] As an example, one end of the code circuit 13 is connected with the code signal end P2 of the touch chip 11, and the other end of the code circuit 13 is used for connecting the touch electrode 222 of the touch screen 2, so as to output a code current to the touch electrode 222 according to the code signal output by the code signal end P2 of the touch chip 11, so that the touch screen 2 can enter the TSP function mode or the EMR function mode. The code circuit 13 herein can be one or multiple, each code circuit 13 can select positive and negative coding mode for coding, and each code circuit 13 can perform multi-way output, that is, can control multiple touch electrodes 222 to code. The control signal end P3 is a port for providing a control signal to the control circuit 223.

[0216] In some possible implementations, the code signal output by the code signal end P2 can be a sine wave signal or a square wave signal, which can be determined autonomously according to actual conditions. The code signal herein can be a first code signal for entering the TSP function mode, or a second code signal for entering the EMR function mode. In the example, the first code signal and the second code signal are preferably sine wave signals, which can make the current more gentle and can better guarantee the function implementation.

[0217] In an embodiment, as shown in FIG. 3, the touch device 1 further comprises a power supply rail 13, one end of the power supply rail 13 is connected with the control signal end P3 of the touch chip 11, and the other end of the power supply rail 13 is used for connecting the control circuit 223 of the touch screen 2.

[0218] The touch chip 11 is used for a control signal in a second voltage range.

[0219] The power supply rail 13 is used for converting the control signal in the second voltage range, and outputting a control signal in a first voltage range to the control circuit 223, so that the control circuit 223 controls the function switching switch 222 to open or close.

[0220] As an example, when the function switch 222 is a TFT, its corresponding first voltage range is a higher voltage range (e.g. 3V-8V). If the touch chip 11 is prepared based on a low-voltage process, the touch chip 11 outputs a control signal in a second voltage range, which is a lower voltage range (e.g. 0V-5V). Therefore, one or more power supply rails 13 are arranged between the touch chip 11 and the switch signal end SW to convert the control signal in the second voltage range into a control signal in the first voltage range, and the function switch 222 is opened or closed. The power supply rail 13 can be a structure for voltage conversion based on a Deep N-WELL isolation (DNW isolation) technology, which is arranged on the touch chip 11. The isolation technology isolates the internal device by isolating a separate area, i.e. a deep N-well (DNW), on the P-sub. The main purpose of isolation from the outside world is to weaken the influence between each other, especially the isolation of potential, such as processing multiple ground potentials (0V, -3.3V, -6V, etc.).

[0221] The touch screen 2 will be described in detail below in combination with the touch device 1 and the touch screen 2 in Embodiments 1-4:

[0222] Embodiment 1

[0223] The embodiment of the present application provides a touch screen 2, as shown in FIG. 1, which is used to connect a touch chip 11. The touch screen 2 comprises a common voltage line 21 and at least two touch units 22.

[0224] Each of the touch units 22 comprises a touch electrode 222, a function switch 221 and a control circuit 223.

[0225] A first end of each of the touch electrodes 222 is connected to the common voltage line 21 through the function switch 221, and a second end of each of the touch electrodes 222 is used to connect a punch code signal end P2 of the touch chip 11. The common voltage line 21 is used to connect a common voltage end P1 of the touch chip 11.

[0226] Each of the control circuits 223 is connected to a control end of the function switch 221 and a connection node between the function switch 221 and the touch electrode 222, and is also used to connect a control signal end P3 of the touch chip 11, for controlling the function switch 221 to be opened or closed according to a control signal output by the control signal end P3.

[0227] The function switch 221 is arranged between the touch electrode 222 and the common voltage line 21, and is a switch for switching the TSP function mode and the EMR function mode. When the function switch 221 is closed, the connection between the touch electrode 222 of different channels and the common voltage line 21 is disconnected, so that a one-way channel is formed between the touch chip 11 and each touch electrode 222, and the touch screen 2 can be controlled to enter the TSP function mode; when the function switch 221 is opened, the touch electrode 222 of different channels is connected together, so that the code signal end P2 of the touch chip 11 and at least two touch electrodes 222 on the same common voltage line 21 form a ring channel, so that the touch chip 11 can control the touch screen 2 to enter the EMR function mode. In the example, the touch electrode 222 can be a driving electrode TX or a sensing electrode RX.

[0228] As an example, the touch screen 2 is provided with a common voltage line 21 and at least two touch units 22, and the touch unit 22 includes but is not limited to a touch electrode 222, a function switch 221 and a control circuit 223. Each function switch 221 is arranged between the touch electrode 222 and the common voltage line 21, that is, the common voltage line 21 is connected to the first end of the at least two function switches 221, and the second end of each function switch 221 is connected to a touch electrode 222. For example, the common voltage line 21 is connected to the common voltage end P1 of the touch chip 11 through the state switch 12, and when the state switch 12 is turned on, the common voltage line 21 can receive the common voltage (for example, GND voltage or voltage close to the value) output by the touch chip 11, and when the state switch 12 is turned off, the common voltage line 21 is in a suspended state. The control circuit 223 is connected to the control signal end P3 of the touch chip 11 and the control end of the function switch 221, can receive the control signal sent by the touch chip 11, and based on the control signal, controls the function switch 221 to be closed and adjusts the control end potential of the function switch 221, so that the control end potential of the function switch 221 follows the code potential change of the touch electrode 222, so as to ensure the implementation of the TSP function mode and the EMR function mode.

[0229] In the case that the function switching switch 221 is a thin film transistor (TFT), the drain of the function switching switch 221 is connected with the common voltage line 21, the source of the function switching switch 221 is connected with the touch electrode 222, and the gate (i.e. the control end) of the function switching switch 221 is connected with the control circuit 223. The control circuit 223 can control the function switching switch 221 to be closed according to the control signal output by the touch chip 11, so that the touch screen 2 enters the TSP function mode, and the touch electrode 222 can receive the first code signal output by the touch chip 11. At this time, the control circuit 223 cooperates with the function switching switch 221 to control the gate voltage of the function switching switch 221 to follow the code potential change of the touch electrode 222, so that the off-state current of the function switching switch 221 is small, and the leakage current of the function switching switch 221 does not affect the TSP function mode of the touch screen 2. In the example, the function switching switch 221 can be a PTFT which is turned on based on a low-level signal and turned off based on a high-level signal, or the function switching switch 221 can be an NTFT which is turned on based on a high-level signal and turned off based on a low-level signal.

[0230] In the example, the control circuit 3 is arranged between the control signal end P3 of the touch chip 11 and the function switching switch 221, and can control the function switching switch 221 to be opened or closed based on the control signal of the control signal end P3. Since the control circuit 3 is not only connected with the control end of the function switching switch 221, but also connected with the connection node between the function switching switch 221 and the touch electrode 222, the code potential change of the touch electrode 222 can be determined during the code process based on the code signal of the touch chip 11, and the control end potential of the touch electrode 222 can be adjusted based on the code potential change, so that the TSP function mode and the EMR function mode can be implemented.

[0231] Embodiment 2

[0232] In an embodiment, as shown in FIG. 2, each control circuit 223 includes a first capacitor C1 and a switch circuit 2231.

[0233] One end of the first capacitor C1 is connected with the control end of the function switching switch 221, and the other end of the first capacitor C1 is connected with the connection node between the function switching switch 221 and the touch electrode 222.

[0234] The first end of the switch circuit 2231 is used to connect the reference voltage end VREF of the touch chip 11, the second end of the switch circuit 2231 is connected with the control end of the function switching switch 221, and the third end of the switch circuit 2231 is used to connect the switch signal end SW of the touch chip 11.

[0235] The switch circuit 2231 is configured to open or close based on a control signal output by the switch signal terminal SW and control the function switching switch 221 to open or close based on a reference voltage output by the reference voltage terminal VREF.

[0236] As an example, one end of the first capacitor C1 is connected to the control terminal of the function switching switch 221, and the other end of the first capacitor C1 is connected to the connection node between the function switching switch 221 and the touch electrode 222, so that the first capacitor C1 cooperates with the function switching switch 221 to form a bootstrap circuit. For example, when the function switching switch 221 is a TFT, the first capacitor C1 is arranged between the gate and the source of the function switching switch 221, so that the first capacitor C1 cooperates with the parasitic capacitor Cgs of the function switching switch 221.

[0237] In this example, since one end of the first capacitor C1 is connected to the control terminal of the function switching switch 221, and the other end of the first capacitor C1 is connected to the connection node between the function switching switch 221 and the touch electrode 222, the first capacitor C1 cooperates with the function switching switch 221 to form a bootstrap circuit, which can make the control terminal of the function switching switch 221 follow the change of the coding potential of the touch electrode 222 during the coding process based on the coding signal of the touch chip 11, so as to guarantee the implementation of the TSP function mode and the EMR function mode. For example, when it is required to control the touch screen 2 to enter the TSP function mode, the touch chip 11 can control the function switching switch 221 to be closed, so that the touch electrode 222 receives the first coding signal of the touch chip 11. At this time, the control circuit 223 cooperates with the function switching switch 221 to control the gate voltage of the function switching switch 221 to follow the change of the coding potential of the touch electrode 222, so that the off-state current of the function switching switch 221 is small, and the leakage current of the function switching switch 221 does not affect the TSP function mode of the touch screen 2.

[0238] In an embodiment, as shown in FIG. 2, the common voltage line 21 is connected to the common voltage terminal P1 through the state switch 12.

[0239] The reference voltage includes a first reference voltage for controlling the function switching switch 211 to be closed.

[0240] The switch circuit 2231 is configured to open based on a first control signal output by the switch signal terminal SW and control the function switching switch 221 to be closed based on the first reference voltage output by the reference voltage terminal VREF, so as to initialize the control terminal potential of the function switching switch 221.

[0241] The switch circuit 2231 is also used to close the function switch 221 based on the second control signal output by the switch signal terminal SW, so that the function switch 221 is maintained in a closed state, and the control terminal of the function switch 221 follows the code signal potential of the touch electrode 222;

[0242] When the state switch 12 is in the on state, the common voltage line 21 is used to receive the common voltage output by the common voltage terminal P1, and the touch electrode 222 is used to receive the first code signal output by the code signal terminal P2, so that the touch screen 2 enters the TSP function mode.

[0243] In some possible implementation manners, when the function switch 221 is TFT, the control process of the touch screen 2 entering the TSP function mode is as follows:

[0244] (1) The switch signal terminal SW of the touch chip 11 can output a first control signal to the switch circuit 2231 to control the switch circuit 2231 to open; at the same time, the reference voltage terminal VREF of the touch chip 11 can output a first reference voltage to the switch circuit 2231, and when the switch circuit 2231 is opened, the first reference voltage can be transmitted to the gate of the function switch 221 to control the function switch 221 to close.

[0245] In this example, the first reference voltage transmitted to the gate of the function switch 221 can initialize the gate potential of the function switch 221, and at the same time, the corresponding touch electrode 222 also has an initial voltage, at this time, the initial voltage difference between the gate and the source of the function switch 221 can be determined, and the initial voltage difference can ensure that the voltage Vgs between the gate and the source of the function switch 221 is less than the on threshold |Vthp|, so that the function switch 221 is in a closed state, and the voltage Vds between the drain and the source of the function switch 221 is also close to 0, so that the off-state current of the function switch 221 is very small. The initial voltage of the touch electrode 222 can be a fixed voltage close to the intermediate voltage of the code waveform, for example, it can be a GND voltage.

[0246] (2) The switch signal terminal SW of the touch chip 11 can output a second control signal to control the switch circuit 2231 to close, so that the gate of the function switch 221 is in a suspended state, and the bootstrap effect of the capacitor unit formed by the first capacitor C1 and the parasitic capacitor Cgs of the function switch 221 itself is used to maintain the gate potential of the function switch 221, so that when the TSP function mode enters the code stage, the gate potential of the function switch 221 can follow the code potential, and the voltage Vgs between the gate and the source of the function switch 221 is less than the on threshold |Vthp|, so that the function switch 221 is in a closed state.

[0247] (3) When the function switch 221 is in the off state, the common voltage terminal P1 is used to output a common voltage to the common voltage line 21, and the code signal terminal P2 of the touch chip 11 can output a first code signal to the code signal terminal P2, so that the touch electrode 222 can receive the first code signal, so that the touch screen 2 enters the TSP function mode. In this process, the voltage Vgs of the function switch 221 changes with the code potential, so that the voltage Vds of the function switch 221 changes, but the final off-state current is small, so as to avoid the influence of the leakage current of the function switch 221 on the realization of the TSP function mode.

[0248] In an embodiment, as shown in FIG. 2, the reference voltage includes a second reference voltage for controlling the switch circuit 2231 to be off;

[0249] The switch circuit 2231 is used to maintain the off state based on the second reference voltage output by the reference voltage terminal VREF when the switch circuit 2231 is off based on the second control signal output by the switch signal terminal SW.

[0250] As an example, the switch signal terminal SW of the touch chip 11 outputs a second control signal to the third terminal of the switch circuit 2231, so that the switch circuit 2231 is off at the same time, and the reference voltage terminal VREF of the touch chip 11 also outputs a second reference voltage to the first terminal of the switch circuit 2231, so as to adjust the voltage of the first terminal of the switch circuit 2231 to the GND voltage or a fixed voltage close to this value, so as to avoid the output signal of other circuits coupled to the first terminal of the switch circuit 2231 changing the voltage of the first terminal of the switch circuit 2231, so that the switch circuit 2231 cannot maintain the off state and affect the realization of the TSP function mode.

[0251] In an embodiment, at least two touch electrodes 222 corresponding to the same common voltage line 21 are used to receive the first code signal output by the code signal terminal P2 at the same time.

[0252] As an example, since the functional switch 221 is closed, the touch chip 11 forms a one-way channel with the plurality of touch electrodes 222, so that the touch chip 11 can output a first punch code signal to at least two touch electrodes 222 corresponding to the same common voltage line 21 through the punch code signal end P2 when the functional switch 221 is in the closed state, so that at least two touch electrodes 222 corresponding to the same common voltage line 21 can simultaneously receive the first punch code signal (the timing is shown in FIGS. 5, 12, 14 and 19), so as to guarantee the punch code efficiency of the TSP function mode. During the punch code process, due to the bootstrap effect of the capacitor unit formed between the first capacitor C1 and the parasitic capacitor Cgs of the functional switch 221, the gate potential of the functional switch 221 can be controlled to follow the change of the punch code potential, so that the off-state current of the functional switch 221 is small.

[0253] In an embodiment, as shown in FIG. 2, the common voltage line 21 is connected to the common voltage end P1 through the state switch 12.

[0254] The reference voltage includes a third reference voltage for controlling the functional switch 221 to be opened;

[0255] The switch circuit 2231 is further configured to be opened based on a first control signal output by the switch signal end SW and to be controlled to be opened based on the third reference voltage output by the reference voltage end VREF.

[0256] When the state switch 12 is in the open state, the touch electrode 222 is configured to receive a second punch code signal output by the punch code signal end P2, so that the touch screen 2 enters the EMR function mode.

[0257] As an example, when the functional switch 221 is TFT, the switch signal end SW of the touch chip 11 can output a first control signal to control the switch circuit 2231 to be opened, and the reference voltage end VREF of the touch chip 11 can output a third reference voltage. When the switch circuit 2231 is opened, the third reference voltage can be transmitted to the gate of the functional switch 221, so that the voltage between the gate and the source of the functional switch 221 is greater than or equal to the on threshold |Vthp|, and the third reference voltage can control the functional switch 221 to be opened. When the state switch 12 is in the open state (such as the HiZ state in FIGS. 7 and 18), that is, the common voltage line 21 is in a suspended state, the punch code signal end P2 of the touch chip 11 forms a ring-shaped channel with at least two touch electrodes 222 on the same common voltage line 21, and the touch electrode 222 can receive the second punch code signal output by the touch chip 11, so that the touch screen 2 enters the EMR function mode.

[0258] In an embodiment, as shown in FIG. 7 and FIG. 8, the common voltage line 21 comprises at least one first common voltage line 211 to which the at least three touch electrodes 222 are connected;

[0259] The at least three touch electrodes 222 corresponding to the same first common voltage line 211 are configured to receive the second code signals outputted by the code signal terminal P2 one by one.

[0260] As an example, the common voltage line 21 can be the first common voltage line 211, which is the common voltage line 21 connected to the at least three touch electrodes 222. In this example, one end of the first common voltage line 211 is configured to be connected to the common voltage terminal P1 of the touch chip 11; the first common voltage line 211 is also connected to the at least three function switching switches 221, each of which is connected to a touch electrode 222. When the state switch 12 is in the off state, i.e., the first common voltage line 211 is in the suspended state, the first common voltage line 211 cooperates with the at least three touch electrodes 222 to form a loop structure similar to a comb structure. Moreover, the second end of the at least three touch electrodes 222 corresponding to the same first common voltage line 211 is also connected to the code signal terminal P2 of the touch chip 11, so that the at least three touch electrodes 222 corresponding to the same first common voltage line 211 can receive the second code signals outputted by the touch chip 11 one by one, so as to ensure that only one touch electrode 222 performs coding based on the second code signal at the same time, avoiding signal crosstalk. This way requires fewer common voltage lines 21, which helps to save cost and occupied area.

[0261] In an embodiment, as shown in FIG. 10 and FIG. 11, the common voltage line 21 comprises at least one second common voltage line 212 to which the at least two touch electrodes 222 are connected;

[0262] The at least two touch electrodes 222 corresponding to the same second common voltage line 212 are configured to receive the second code signals outputted by the code signal terminal P2 simultaneously.

[0263] As an example, the common voltage line 21 can be a second common voltage line 212, which is the common voltage line 21 connected with two touch electrodes 222. In this example, one end of the second common voltage line 212 is connected with the common voltage end P1 of the touch chip 11; the second common voltage line 212 is also connected with two function switching switches 221, each of which is connected with a touch electrode 222. When the state switch 12 is in the off state, i.e., the second common voltage line 212 is in a suspended state, a ring-shaped channel is formed between the two touch electrodes 222 corresponding to the second common voltage line 212 and the touch code signal end P2 of the touch chip 11, so that the two touch electrodes 222 corresponding to the same second common voltage line 212 can receive the second touch code signal output by the touch chip 11 at the same time, so that two touch electrodes 222 can code based on the second touch code signal at the same time. This way can effectively shorten the coding time and help improve the coding efficiency.

[0264] In an embodiment, as shown in FIG. 3, the switch circuit 2231 includes a first control switch TFT1;

[0265] The first end of the first control switch TFT1 is used to connect the reference voltage end VREF of the touch chip 11, the second end of the first control switch TFT1 is connected with the control end of the function switching switch 221, and the control end of the first control switch TFT1 is used to connect the switch signal end SW of the touch chip 11.

[0266] The first control switch TFT1 is used to open based on the first control signal output by the switch signal end SW, or close based on the second control signal output by the switch signal end SW.

[0267] As an example, the switch circuit 2231 includes a first control switch TFT1, which is arranged between the reference voltage end VREF of the touch chip 11 and the control end of the function switching switch 221. The control end of the first control switch TFT1 is connected with the switch signal end SW of the touch chip 11, and can be opened based on the first control signal output by the switch signal end SW of the touch chip 11, and closed based on the second control signal output by the switch signal end SW of the touch chip 11. In this example, the first control switch TFT1 can be a PTFT, which is opened based on a low-level signal and closed based on a high-level signal; or the first control switch TFT1 can also be an NTFT, which is turned on based on a high-level signal and turned off based on a low-level signal.

[0268] As shown in FIG. 3, the control circuit 223 includes a switch circuit 2231 and a first capacitor C1, two ends of the first capacitor C1 are connected with the gate and the source of the function switching switch 221 respectively, so that the first capacitor C1 cooperates with the function switching switch 221 to form a bootstrap circuit which can realize bootstrap effect. The switch circuit 2231 includes a first control switch TFT1, a first end of the first control switch TFT1 is connected with a reference voltage end VREF of the touch chip 11, and can receive the reference voltage VREF output by the touch chip 11; a second end of the first control switch TFT1 is connected with the gate of the function switching switch 221; a control end of the first control switch TFT1 is connected with a switch signal end SW of the touch chip 11, and can control the first control switch TFT1 to open or close according to different level signals output by the touch chip 11, so as to determine whether the reference voltage VREF provided by the touch chip 11 can be transmitted to the function switching switch 221, and control the function switching switch 221 to open or close based on the reference voltage VREF.

[0269] In the example, the control circuit 223 includes the switch circuit 2231 and the first capacitor C1, the switch circuit 2231 includes the first control switch TFT1, and the first control switch TFT1 and the first capacitor C1 cooperate to control the first control switch TFT1 to open based on the first control signal output by the touch chip 11, so that the first reference voltage output by the touch chip 11 is transmitted to the gate of the function switching switch 221, and the gate potential of the function switching switch 221 is initialized when the function switching switch 221 is in the closed state; and the first control switch TFT1 is controlled to close based on the second control signal output by the touch chip 11, so that the function switching switch 221 remains in the closed state, and the first capacitor C1 and the function switching switch 221 cooperate to form a bootstrap circuit when the TSP function mode enters the code input stage, so that the gate potential of the function switching switch 221 follows the code input potential of the touch electrode 222, so that the off-state current of the function switching switch 221 is small, so as to avoid the influence of the leakage current of the function switching switch 221 on the implementation of the TSP function mode.

[0270] For example, the touch electrode 222 can be a driving electrode TX or a sensing electrode RX. Taking the driving electrode TX as an example, the touch electrodes 222 in the two touch units 22 are respectively TFT1 / TFT2. The function switching switch 221 can be a PTFT or an NTFT. Taking the PTFT as an example, the function switching switches 221 in the two touch units 22 are respectively PTFT1 / PTFT2 in the embodiment. For the purpose of comparison, the function switching switches 221 in the two touch units 22 are respectively PTFT3 / PTFT4 in the prior art. The first control switch TFT1 can be a PTFT or an NTFT. Taking the PTFT as an example, the first control switches TFT1 in the two touch units 22 are respectively TFT1 / TFT2 in order to distinguish from the PTFT in the function switching switch 221. The left drawing in FIG. 4 is a schematic diagram of the touch screen 2 in the embodiment, and the right drawing in FIG. 4 is a schematic diagram of the touch screen 2 in the prior art. The working process of the control circuit 223 of the adjacent channel in the TSP function mode is as follows in combination with the timing diagram in FIG. 5 and the simulation diagram in FIG. 6:

[0271] (1) Before the touch screen 2 enters the TSP function mode, the touch chip 11 outputs a low-level signal to the control end of the first control switch TFT1 / TFT2, so that the first control switch TFT1 / TFT2 is opened. At the same time, the touch chip 11 outputs a first reference voltage Vo to the first end of the first control switch TFT1 / TFT2. When the first control switch TFT1 / TFT2 is opened, the first reference voltage Vo of the touch chip 11 can be transmitted to the gate N1 / N2 of the function switching switch PTFT1 / PTFT2, so as to control the function switching switch PTFT1 / PTFT2 to be closed. Specifically, the first reference voltage Vo is transmitted to the gate N1 / N2 of the function switching switch PTFT1 / PTFT2 for initialization, and the corresponding driving electrode TX1 / TX2 also has an initial voltage. The voltage difference between the first reference voltage Vo and the initial voltage of the touch electrode TFT1 / TFT2 is small, so that the voltage Vgs of the function switching switch PTFT1 / PTFT2 is less than the conduction threshold value |Vthp|, at this time, the function switching switch PTFT1 / PTFT2 is always kept in the closed state, and the voltage Vds of the function switching switch PTFT1 / PTFT2 is also close to 0, so that the off-state current of the function switching switch PTFT1 / PTFT2 is very small. The initial voltage of the touch electrode TFT1 / TFT2 can be a fixed voltage close to the middle voltage of the coding waveform, for example, it can be a GND voltage.

[0272] (2) After the initialization of the gate N1 / N2 of the function switching switch PTFT1 / PTFT2, the touch chip 11 outputs a high-level signal to the control end of the first control switch TFT1 / TFT2, gradually pulls up the level of the first control switch TFT1 / TFT2, so that the first control switch TFT1 / TFT2 is closed, and the touch chip 11 outputs a second reference voltage to the first control switch TFT1 / TFT2, which can be a GND voltage or a voltage close to the value, so as to avoid interference with other circuits coupled with the first control switch TFT1 / TFT2, so that the switch circuit 2231 cannot maintain the closed state and affect the TSP function mode implementation; when the first control switch TFT1 / TFT2 is closed, the gate N1 / N2 of the function switching switch PTFT1 / PTFT2 is in a suspended state, and based on the cooperation of the first capacitor C11 / C12 and the parasitic capacitor Cgs of the function switching switch PTFT1 / PTFT2, the potential of the gate N1 / N2 of the function switching switch PTFT1 / PTFT2 is maintained.

[0273] (3) When the TSP function mode enters the code phase, the touch chip 11 outputs a first code signal to the driving electrode TX1 / TX2 through the code signal end P2, so that the driving electrode TX1 / TX2 can receive the first code signal. Due to the bootstrap effect of the first capacitor C11 / C12 and the parasitic capacitor Cgs of the function switching switch PTFT1 / PTFT2, the potential of the gate N1 / N2 of the function switching switch PTFT1 / PTFT2 changes with the code potential of TX1 / TX2, and the voltage Vgs of the function switching switch PTFT1 / PTFT2 is kept less than the conduction threshold |Vthp|, so that the function switching switch PTFT1 / PTFT2 is closed. Since the voltage Vgs of the function switching switch PTFT1 / PTFT2 changes with the code potential, even if its voltage Vds changes, the final off-state current will be small, so as to avoid the influence of the drain current of the function switching switch PTFT1 / PTFT2 on the implementation of the TSP function mode. In this example, when the touch chip 11 outputs the first code signal to the driving electrode TX1 / TX2, the common voltage end P1 also outputs a common voltage, which can be a GND voltage or a voltage close to the value, so as to maintain the closed state of the function switching switch PTFT1 / PTFT2. Since the function switching switch 221 is closed, the touch chip 11 and the plurality of touch electrodes TFT1 / TFT2 form a one-way channel, so that the code signal end P2 of the touch chip 11 can output the first code signal to at least two driving electrodes TX1 / TX2, so that all driving electrodes TX1 / TX2 can code at the same time, and the code efficiency of the TSP function mode is guaranteed.

[0274] As shown in FIG. 4, in the prior art, the gate of the function switching switch PTFT3 / PTFT4 is connected with the switch signal end SW of the touch chip 11, and the function switching switch PTFT3 / PTFT4 can be controlled to be closed based on the DC voltage output by the switch signal end SW, so that the gate potential of the function switching switch PTFT3 / PTFT4 is a fixed value. Although the voltage Vgs of the function switching switch PTFT3 / PTFT4 can be controlled to be less than the conduction threshold |Vthp|, when the TSP function mode enters the code printing stage, the voltage Vgs of the function switching switch PTFT3 / PTFT4 changes with the code printing potential, and the fluctuation of the voltage Vgs of the function switching switch PTFT3 / PTFT4 is large. In combination with the change of the voltage Vds of the function switching switch PTFT3 / PTFT4, the leakage current of the function switching switch PTFT3 / PTFT4 is large in the time period of 1 / 2T at different swing positions of the code printing potential, which causes the mutual crosstalk between the driving electrodes TX1 / TX2, and further affects the TSP function mode.

[0275] As shown in FIG. 5 and FIG. 6, under the control of the fixed DC voltage, the leakage current of the function switching switch PTFT3 / PTFT4 is large, which is greater than 230pA in the figures. The function switching switch PTFT1 / PTFT2 and the first capacitor C11 / C12 form a bootstrap circuit, so that the gate potential of the function switching switch PTFT1 / PTFT2 changes with the code printing potential of the driving electrode TX1 / TX2, and the leakage current of the function switching switch PTFT1 / PTFT2 is always maintained below 10pA, so that the off-state current of the function switching switch 221 is small, and the leakage current of the function switching switch 221 does not affect the implementation of the TSP function mode.

[0276] The working process of the control circuit 223 of the adjacent channel in the EMR function mode is as follows: before the touch screen 2 enters the code printing stage of the EMR function mode, the touch chip 11 outputs a low-level signal to the control end of the first control switch TFT1 / TFT2, so that the first control switch TFT1 / TFT2 is opened and maintained in the always-on state; at the same time, the touch chip 11 outputs the third reference voltage to the first end of the first control switch TFT1 / TFT2. When the first control switch TFT1 / TFT2 is opened, the third reference voltage of the touch chip 11 can be transmitted to the gate N1 / N2 of the function switching switch PTFT1 / PTFT2, so as to control the function switching switch PTFT1 / PTFT2 to be opened.

[0277] In some possible embodiments, as shown in FIG. 7, when the touch chip 11 outputs the third reference voltage, the state switch 12 is also controlled to be disconnected, so that the common voltage terminal P1 of the touch chip 11 is disconnected from the common voltage line 21, and the common voltage line 21 is in a suspended state, so that at least three touch electrodes 222 are connected together through the first common voltage line 211 to form a coil structure similar to a comb structure, and the equivalent result is shown in FIG. 8, at this time, the N1 to Nn nodes are all in a low level state, to ensure that all the function switching switches PTFT are in a fully open state; the at least three touch electrodes 222 corresponding to the same first common voltage line 211 are connected to the code signal terminal P2 of the touch chip 11, and then the code signal terminal P2 outputs the second code signal to the at least three touch electrodes 222 one by one, that is, the touch electrodes 222 of a specific channel are selected to provide a sine wave signal or an intermediate potential, to determine the current direction of the comb junction, and then form various electromagnetic coil networks, to ensure that only one touch electrode 222 based on the second code signal performs code marking at the same time, to avoid signal crosstalk, and this way requires fewer common voltage lines 21, which helps to save cost and occupied area.

[0278] In another specific embodiment, when the touch chip 11 outputs the third reference voltage, the state switch 12 is also controlled to be disconnected, so that the common voltage terminal P1 of the touch chip 11 is disconnected from the common voltage line 21, and the common voltage line 21 is in a suspended state, so that two touch electrodes 222 are connected together through the second common voltage line 212, and FIG. 10 shows that two adjacent touch electrodes 222 are connected together through the second common voltage line, to realize the equivalent structure of different coil combinations; and FIG. 11 shows that two different touch electrodes 222 are connected together through the second common voltage line at a certain interval, to realize the equivalent structure of different coil combinations. The two touch electrodes 222 corresponding to the same second common voltage line 212 are connected to the code signal terminal P2 of the touch chip 11, so that the code signal terminal P2 outputs the second code signal to the two touch electrodes 222 at the same time, to ensure that two touch electrodes 222 based on the second code signal can perform code marking at the same time, and this way can effectively shorten the code time, and helps to improve the code efficiency.

[0279] As shown in FIG. 12, from the complete working timing of the touch screen 2, the TSP function mode and the EMR function mode are time-sharing working, and different signals need to be outputted by the touch chip 11 to control the touch screen 2 to complete the switching of the TSP function mode and the EMR function mode. In the present example, the touch chip 11 needs to control the touch screen 2 to complete the initialization operation again after the touch screen 2 completes the TSP function mode and the EMR function mode once, that is, the first reference voltage outputted by the reference voltage terminal VERF is used to initialize the potential (i.e. the gate potential) of the control terminal of the function switching switch 221, so as to ensure the accuracy of the control process and avoid the accumulated error of multiple operations affecting the control accuracy.

[0280] In an embodiment, as shown in FIG. 13, the switch circuit 2231 further comprises a voltage lifting circuit 22311 connected with the connection node between the second terminal of the first control switch TFT1 and the control terminal of the function switching switch 221;

[0281] The voltage lifting circuit 22311 is further used for connecting the control signal terminal P3 of the touch chip 11, for lifting the control signal of the second voltage range outputted by the common voltage terminal P1 and converting it into the control signal of the first voltage range, so as to control the function switching switch 222 to open or close.

[0282] As an example, when the function switching switch 222 is TFT, the first voltage range used to control the TFT to open or close is the higher voltage range (e.g. 3V-8V), and if the touch chip 11 is prepared based on the low-voltage process technology, the touch chip 11 outputs the control signal of the second voltage range. At this time, the voltage lifting circuit 22311 needs to be set on the touch screen 2, which is set between the control signal terminal P3 of the touch chip 11 and the control terminal of the function switching switch 221, and can lift the control signal of the second voltage range outputted by the common voltage terminal P1 and convert it into the control signal of the first voltage range, so as to control the function switching switch 222 to open or close. In the present example, due to the signal lifting of the voltage lifting circuit 22311 set on the touch screen 2, the voltage range used to control the switch to open or close can be appropriately reduced, and the touch chip 11 manufactured by the conventional low-voltage process technology can be used to control the touch screen 2, without the need to select the touch chip 11 manufactured by the special high-voltage process technology, which helps to reduce the cost of the touch chip 11.

[0283] In an embodiment, as shown in FIG. 13, the voltage lifting circuit 22311 comprises a second control switch TFT2, a third control switch TFT3, a fourth control switch TFT4, a fifth control switch TFT5 and a second capacitor C2;

[0284] The second control switch TFT2, the third control switch TFT3 and the fourth control switch TFT4 are connected in series, and the fourth control switch TFT4 is connected with the control end of the function switching switch 221.

[0285] The control end of the first control switch TFT1 is used for connecting the first switch signal end SW1 of the touch chip 11 to receive the first switch signal output by the first switch signal end SW1.

[0286] The first end of the second control switch TFT2 is used for connecting the input end IN of the touch chip 11 to receive the first voltage output by the input end IN, and the control end of the second control switch TFT2 is used for connecting the second switch signal end SW2 of the touch chip 11 to receive the second switch signal output by the second switch signal end SW2.

[0287] The control end of the third control switch TFT3 is used for connecting the negative voltage supply end VEE of the touch chip 11 to receive the VEE voltage output by the negative voltage supply end VEE.

[0288] The first end of the fifth control switch TFT5 is used for connecting the clock signal end CLK of the touch chip 11, the second end of the fifth control switch TFT5 is connected with the connection node between the third control switch TFT3 and the fourth control switch TFT4, and the control end of the fifth control switch TFT5 is connected with the control end of the fourth control switch TFT4.

[0289] The two ends of the second capacitor C2 are connected with the second end of the fifth control switch TFT5 and the control end of the fifth control switch TFT5 respectively.

[0290] The voltage lifting circuit 22311 is used for controlling the voltage lifting of the voltage lifting circuit 22311 based on the first switch signal, the second switch signal, the first voltage, the VEE voltage and the second voltage.

[0291] As an example, as shown in FIG. 18, the first control switch TFT1 is used to connect the first switch signal end SW1 of the touch chip 11; the voltage lifting circuit 22311 includes a second control switch TFT2, a third control switch TFT3, a fourth control switch TFT4, a fifth control switch TFT5 and a second capacitor C2; the second control switch TFT2, the third control switch TFT3 and the fourth control switch TFT4 are connected in series, and the fourth control switch TFT4 is connected with the control end of the function switching switch PTFT1; the first end of the second control switch TFT2 is used to connect the input end IN of the touch chip 11, and the control end of the second control switch TFT2 is used to connect the second switch signal end SW2 of the touch chip 11; the control end of the third control switch TFT3 is used to connect the negative voltage supply end VEE of the touch chip 11; the control end of the fourth control switch TFT4 is connected with the control end of the fifth control switch TFT5; the first end of the fifth control switch TFT5 is used to connect the clock signal end CLK of the touch chip 11, and the second end of the fifth control switch TFT5 is connected with the connection node between the third control switch TFT3 and the fourth control switch TFT4; the two ends of the second capacitor C2 are connected with the second end of the fifth control switch TFT5 and the control end of the fifth control switch TFT5 respectively.

[0292] In the example, the first control switch TFT1 can be controlled to open or close according to the first switch signal output by the first switch signal end SW1, the second control switch TFT2 can be controlled to open or close according to the second switch signal output by the second switch signal end SW2, and the first voltage output by the input end IN to the second control switch TFT2, the VEE voltage output by the negative voltage supply end VEE to the third control switch TFT3, the second voltage output by the clock signal end CLK to the fifth control switch TFT4, and the reference voltage output by the reference voltage end VREF to the first control switch TFT1 are compared to control the voltage difference between the two ends of each control switch, so as to control the third control switch TFT3, the fourth control switch TFT4 and the fifth control switch TFT5 to open or close, so as to realize the voltage lifting purpose while switching between the TSP function mode and the EMR function mode.

[0293] In an embodiment, the first control switch TFT1 is used to open based on the first control signal output by the first switch signal end SW1, and the first control switch TFT1 is controlled to close based on the first reference voltage output by the reference voltage end VREF.

[0294] The second control switch TFT2 is opened based on the first control signal output by the second switch signal end SW2, transmits the VDD voltage output by the input end IN to the N3 node, and the negative voltage supply end VEE outputs the VEE voltage to the third control switch TFT3, so that the third control switch TFT3 is in the always-on state. At this time, the VDD voltage output by the input end IN can be transmitted to the N2 node. When the VDD voltage is greater than the reference voltage, the potential of the N2 node is higher than that of the N1 node, so that the fourth control switch TFT4 is in the closed state in the entire TSP working interval, and the gate potential of the function switching switch PTFT can be initialized based on the reference voltage. At the same time during this period, the N1 node is at a high potential, the second control switch TFT2 is closed based on the second control signal output by the second switch signal end SW2, the N2 node is at a high potential, the clock signal end CLK is used to output the GND voltage to the fourth control switch TFT4, so that the fifth control switch TFT5 is closed, and the off-state current of the fifth control switch TFT5 is also as small as possible, reducing the static current consumption of the entire system.

[0295] As an example, as shown in FIG. 14 and FIG. 15, the touch chip 11 sequentially performs the following operations to control the touch screen 2 to enter the TSP function mode:

[0296] The first control switch TFT1 is opened based on the first control signal output by the first switch signal end SW1, transmits the reference voltage output by the reference voltage end VREF to the gate node (i.e. the N1 node) of the function switching switch PTFT1, so that the gate potential of the function switching switch PTFT1 is adjusted from the initial GND voltage to the reference voltage.

[0297] The second control switch TFT2 is opened based on the first control signal output by the second switch signal end SW2 to transmit the VDD voltage output by the input end IN to the N3 node, and the negative voltage supply end VEE outputs the VEE voltage to the third control switch TFT3, so that the third control switch TFT3 is in the always-on state. At this time, the VDD voltage output by the input end IN can be transmitted to the N2 node. When the VDD voltage is greater than the reference voltage, the potential of the N2 node is higher than that of the N1 node, so that the fourth control switch TFT4 is in the closed state in the entire TSP working interval, and the gate potential of the function switching switch PTFT can be initialized based on the reference voltage. At the same time during this period, the N1 node is at a high potential, the second control switch TFT2 is closed based on the second control signal output by the second switch signal end SW2, the N2 node is at a high potential, the clock signal end CLK is used to output the GND voltage to the fourth control switch TFT4, so that the fifth control switch TFT5 is closed, and the off-state current of the fifth control switch TFT5 is also as small as possible, reducing the static current consumption of the entire system.

[0298] In this example, when the touch chip 11 controls the touch screen 2 to enter the TSP function mode, the first control switch TFT1 is first opened based on the first control signal output by the first switch signal end SW1 to transmit the reference voltage output by the reference voltage end VREF to the N1 node, to complete the initialization of the gate potential of the function switching switch PTFT1, and other circuits in the circuit remain closed after initialization. The process of the code phase in the TSP function mode is the same as that in the above-mentioned embodiment, and is not repeated here.

[0299] In an embodiment, the first control switch TFT1 is configured to open based on the first control signal output by the first switch signal terminal SW1 and control the function switch 221 to open based on the VEE voltage output by the reference voltage terminal VREF.

[0300] The second control switch TFT2 is configured to open based on the first control signal output by the second switch signal terminal SW2, transmit the VEE voltage output by the input terminal IN to a node between the fourth control switch TFT4 and the fifth control switch TFT5, and the fifth control switch TFT5 receives the GND voltage output by the clock signal terminal CLK to make the fourth control switch TFT4 close and the fifth control switch TFT5 open.

[0301] The first control switch TFT1 is configured to close based on the second control signal output by the first switch signal terminal SW1, the second control switch TFT2 is configured to close based on the second control signal output by the second switch signal terminal SW2, and the fifth control switch TFT5 receives the VEE voltage output by the clock signal terminal CLK to make the fourth control switch TFT4 and the fifth control switch TFT5 open.

[0302] As an example, as shown in FIGS. 16-19, the touch screen 2 sequentially performs the following state corresponding control operations to make the touch screen 2 enter the EMR function mode:

[0303] State 1: The first control switch TFT1 pulls the first end potential of the first control switch TFT1 to the low level VEE based on the reference voltage output by the reference voltage terminal VREF, and the first control switch TFT1 opens based on the first control signal output by the first switch signal terminal SW1 to make the N1 node keep VEE+|Vthp|, since the PTFT1 is a unipolar PTFT, the lowest potential opening will lose one |Vthp|.

[0304] State 2: The first end of the second control switch TFT2 receives the low level VEE output by the input end IN of the touch chip 11, and the second control switch TFT2 is opened based on the first control signal output by the second switch signal end SW2, so that the low level VEE received by the first end of the second control switch TFT2 is adjusted through the third control switch TFT3 to adjust the potential of the N2 node to VEE+2x|Vthp|, based on which, the fourth control switch TFT4 is connected as a diode Connect tube, Vsg<|Vthp|, so that the fourth control switch TFT4 will not be opened, and the potential of the N1 node and the potential of the N2 node are maintained respectively. At the same time, the first end of the fifth control switch TFT5 receives the GND voltage output by the clock signal end CLK of the touch chip 11, and the N2 node potential controls the fifth control switch TFT5 to be opened. Wherein, the gate of the third control switch TFT3 is connected to the negative voltage supply end VEE, so that it is only used as a limiting tube for reverse limiting current.

[0305] State 3: The first control switch TFT1 is closed based on the second control signal output by the first switch signal end SW1, and the second control switch TFT2 is closed based on the second control signal output by the second switch signal end SW2, i.e. the control signals of the first switch signal end SW1 and the second switch signal end SW2 are pulled high, so that the first control switch TFT1 and the second control switch TFT2 are closed. The first end of the fifth control switch TFT5 is based on the control signal output by the clock signal end CLK, so that the first end of the fifth control switch TFT5 is changed from the GND level to the VEE level. Since the fifth control switch TFT5 and the second capacitor C2 form a bootstrap structure, the potential of the N4 node will be pulled to the VEE potential, and the N2 node will also change from VEE+2x|Vthp| to 2xVEE+2x|Vthp|. At this time, since the fourth control switch TFT4 satisfies Vsg>|Vthp|, the potential of the N1 node is adjusted to 2xVEE+3x|Vthp|, based on which, the potential of the N1 node can be less than VEE through the above structure, that is, the demand for a larger driving voltage range can be met.

[0306] The process used by the conventional touch chip 11 is based on the VDD-VEE range, generally a low-voltage process of +5V to -5V, while the high and low voltage range of the conventional PTFT is +8V to -8V. Therefore, the above circuit through the first bootstrap can lower the control level of the N1 node below the VEE level, so as to better control the on-resistance Rdson of the PTFT1, since the Vds of the PTFT1 is fixed, and the lower the Vg, the smaller the Rdson. In this example, since the subsequent TX1 uses a sine wave signal in the EMR coding phase, a small part of the fluctuation is also coupled to the N1 node through the first capacitor C1, and a part of the jitter is also filtered through the fourth control switch TFT4, so that the disturbance of the N2 node is smaller. In this example, after the touch chip 11 controls the touch screen 2 to complete a TSP function mode and / or an EMR function mode, the touch chip 11 needs to control the touch screen 2 to complete an initialization operation again, that is, the reference voltage output by the reference voltage terminal VERF is used to initialize the control terminal potential (i.e., the gate potential) of the function switching switch 221, so as to ensure the accuracy of the control process and avoid the influence of the cumulative error of multiple operations on the control accuracy.

[0307] In this example, when the touch chip 11 controls the touch screen 2 to enter the EMR function mode, the potentials of the N1 node and the N2 node are first lowered, then the potential of the clock signal terminal CLK is converted from GND voltage to VEE voltage, the bootstrap architecture formed by the fifth control switch TFT5 and the second capacitor C2 is used to pull the potential of the N2 node to a lower level, and the fourth control switch TFT4 is used to transmit a lower level to the N1 node, so as to achieve the purpose of adjusting the N1 node to a lower level than VEE, and thus achieve the purpose of using a standard TP-IC process to achieve a larger driving voltage range control.

[0308] The electronic device provided by the embodiment of the present application includes the touch chip 11 and the touch screen 2 in the above embodiment, and the touch chip 11 is connected to the touch screen 2; or the electronic device includes the touch device 1 and the touch screen 2 in the above embodiment, and the touch device 1 is connected to the touch screen 2.

[0309] As an example, as shown in FIGS. 20 and 21, the electronic device can include the touch chip 11 and the touch screen 2 in the above embodiment, and the touch chip 11 is connected to the touch screen 2, and the touch chip 11 is connected to the touch screen 2 and can control entering the TSP function mode or the EMR function mode. The touch chip 11 here can be provided with a built-in switch for controlling the public voltage terminal P1 to be in a suspended state, and the touch chip 11 is built-in with a circuit for realizing the coding function, so that it can control the built-in switch to be opened or closed according to the actual demand, and control the circuit for realizing the coding function to work, so as to switch into the TSP function mode or the EMR function mode.

[0310] As another example, as shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 8, the electronic device can include the touch control device 1 and the touch screen in the above-mentioned embodiments, the touch control device 1 not only includes the touch control chip 11, but also includes at least one of the state switch 12, the code striking circuit 13 and the power rail 14 for connecting the touch control chip 11 and the touch screen 2, so as to control the touch screen 2 to enter the TSP function mode or the EMR function mode through the touch control device 1.

[0311] The electronic device in the embodiments of the present application can be a terminal device, a mobile phone, a tablet computer and its accessory keyboard, a notebook computer, a desktop computer, a game device, a vehicle-mounted electronic device or a wearable smart device, etc. portable or mobile computing device, and an electronic database, an automobile, an automatic teller machine (ATM and other electronic devices. The wearable smart device includes a device with full functions, large size, and can realize complete or partial functions without relying on a smart phone, such as a smart watch or smart glasses, etc., and a device that only focuses on a certain type of application function and needs to be used with other devices such as a smart phone, such as various types of smart wristbands, smart jewelry and other devices for monitoring vital signs.

[0312] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A touch chip for connecting a touch screen, characterized by, The touch screen comprises a common voltage line and at least two touch units; each of the touch units comprises a touch electrode, a function switching switch and a control circuit; a first end of each of the touch electrodes is connected to the common voltage line through the function switching switch; each of the control circuits is connected to a control end of the function switching switch and a connection node between the function switching switch and the touch electrode; The touch chip comprises a common voltage end, a code signal end and a control signal end; The common voltage end is connected to the common voltage line; The code signal end is connected to a second end of at least two of the touch electrodes; The control signal end is connected to the control circuit, and the control signal end is used for outputting a control signal to the control circuit, so that the control circuit controls the function switching switch to be opened or closed.

2. The touch chip according to claim 1, wherein, Each of the control circuits comprises a first capacitor and a switch circuit; one end of the first capacitor is connected to the control end of the function switching switch, and the other end of the first capacitor is connected to the connection node between the function switching switch and the touch electrode; a second end of the switch circuit is connected to the control end of the function switching switch; The control signal end comprises a reference voltage end and a switch signal end; the reference voltage end is connected to a first end of the switch circuit, and the switch signal end is connected to a third end of the switch circuit; The switch signal end outputs a control signal to the switch circuit, so that the switch circuit is opened or closed, and the reference voltage end outputs a reference voltage to the switch circuit, based on which the function switching switch is controlled to be opened or closed.

3. The touch chip of claim 2, wherein, The common voltage end is connected to the common voltage line through a state switch; The reference voltage comprises a first reference voltage used for controlling the function switching switch to be closed; The switch signal end is used for outputting a first control signal to the switch circuit, so that the switch circuit is opened, and the reference voltage end is used for outputting the first reference voltage to the switch circuit, so as to control the function switching switch to be closed and initialize a potential of the control end of the function switching switch; The switch signal end is used for outputting a second control signal to the switch circuit, so that the switch circuit is closed, the function switching switch is maintained in a closed state, and a potential of the control end of the function switching switch follows a code potential change of the touch electrode; When the state switch is in a conducting state, the common voltage end is used for outputting a common voltage to the common voltage line, and the code signal end is used for outputting a first code signal to the touch electrode, so that the touch screen enters a TSP function mode.

4. The touch chip of claim 3, wherein, The reference voltage comprises a second reference voltage used for controlling the switch circuit to be closed; When the switch signal end is used for outputting a second control signal to the switch circuit, the reference voltage end outputs the second reference voltage to the switch circuit, so that the switch circuit is maintained in a closed state.

5. The touch chip according to claim 3, wherein, The code signal end is used for simultaneously outputting a first code signal to at least two of the touch electrodes. 6.The touch chip of claim 2, wherein, The common voltage end is connected to the common voltage line through a state switch; The reference voltage comprises a third reference voltage for controlling the functional switch to open; The switch signal end is configured to output a first control signal to the switch circuit to make the switch circuit open, and the reference voltage end is configured to output the third reference voltage to the switch circuit to control the functional switch to open; When the state switch is in the off state, the code signal end is configured to output a second code signal to the touch electrode to make the touch screen enter an EMR function mode.

7. The touch chip of claim 6, wherein, The common voltage line comprises a first common voltage line connected with at least three touch electrodes; The code signal end is configured to output a second code signal to the at least three touch electrodes corresponding to the same first common voltage line one by one.

8. The touch chip of claim 6, wherein, The common voltage line comprises a second common voltage line connected with two touch electrodes; The code signal end is configured to output a second code signal to the two touch electrodes corresponding to the same second common voltage line at the same time.

9. The touch chip of claim 2, wherein, The switch circuit comprises a first control switch, a second end of the first control switch being connected with a control end of the functional switch; The reference voltage end is connected with a first end of the first control switch, and the switch signal end is connected with a control end of the first control switch; The switch signal end outputs a first control signal to the first control switch to make the first control switch open, or outputs a second control signal to the first control switch to make the first control switch close.

10. The touch chip of claim 9, wherein, The switch circuit further comprises a voltage lifting circuit connected with a connection node between the second end of the first control switch and the control end of the functional switch; The control signal end is further configured to be connected with the voltage lifting circuit, and output a control signal in a second voltage range to the voltage lifting circuit to make the voltage lifting circuit lift the control signal in the second voltage range and convert it into a control signal in a first voltage range to control the functional switch to open or close. The voltage lifting circuit comprises a second control switch, a third control switch, a fourth control switch, a fifth control switch and a second capacitor; the second control switch, the third control switch and the fourth control switch are connected in series; the fourth control switch is connected with the control end of the functional switch; a second end of the fifth control switch is connected with a connection node between the third control switch and the fourth control switch, and a control end of the fifth control switch is connected with a control end of the fourth control switch; two ends of the second capacitor are respectively connected with the second end of the fifth control switch and the control end of the fifth control switch; 11. The touch chip of claim 10, wherein, The switch signal end comprises a first switch signal end and a second switch signal end; the control signal end further comprises an input end, a negative voltage supply end and a clock signal end; The first switch signal end is configured to connect the control end of the first control switch and output a first switch signal to the first control switch; the second switch signal end is configured to connect the control end of the second control switch and output a second switch signal to the second control switch; ​ The input end is used for connecting the first end of the second control switch and outputting a first voltage to the second control switch; the negative voltage supply end is used for connecting the control end of the third control switch and outputting a VEE voltage to the third control switch; and the clock signal end is used for connecting the first end of the fifth control switch and outputting a second voltage to the fifth control switch; and the voltage lifting circuit is controlled to perform voltage lifting based on the first switch signal, the second switch signal, the first voltage, the VEE voltage and the second voltage.

12. The touch chip of claim 11, wherein, The first switch signal end is used for outputting a first control signal to the first control switch to make the first control switch open, and the reference voltage end is used for outputting a first reference voltage to the first control switch to make the function switch switch close; The second switch signal end is used for outputting a first control signal to the second control switch to make the second control switch open, the input end is used for outputting a VDD voltage to the second control switch, and the clock signal end is used for outputting a GND voltage to the fourth control switch and the fifth control switch to make the fourth control switch and the fifth control switch close.

13. The touch chip of claim 11, wherein, The first switch signal end is used for outputting a first control signal to the first control switch to make the first control switch open, and the reference voltage end is used for outputting a VEE voltage to the first control switch to make the function switch switch open; The second switch signal end is used for outputting a first control signal to the second control switch to make the second control switch open, the input end is used for outputting a VEE voltage to the second control switch, the clock signal end is used for outputting a GND voltage to the fifth control switch to make the fourth control switch close and the fifth control switch open; The first switch signal end is used for outputting a second control signal to the first control switch to make the first control switch close, the second switch signal end is used for outputting a second control signal to the second control switch to make the second control switch close, and the clock signal end is used for outputting a VEE voltage to the fifth control switch to make the fourth control switch and the fifth control switch open.

14. The touch chip according to any one of claims 1-13, wherein, The touch chip is used for outputting a control signal in a first voltage range to the control circuit to make the control circuit control the function switch to open or close.

15. A touch device, comprising: The touch chip and the state switch according to any one of claims 1-14 are included. One end of the state switch is connected to the common voltage end of the touch chip, and the other end of the state switch is used for connecting a common voltage line of the touch screen. 16.The touch device of claim 15, wherein, The touch device further comprises a code striking circuit. One end of the code striking circuit is connected to the code striking signal end of the touch chip, and the other end of the code striking circuit is used for connecting a touch electrode of the touch screen.

17. The touch control device according to claim 15, wherein, The touch device further comprises a power supply rail, one end of the power supply rail is connected to the control signal end of the touch chip, and the other end of the power supply rail is used for connecting a control circuit of the touch screen. The touch chip is used for outputting a control signal in a second voltage range. The power rail is configured to convert the control signal in the second voltage range, output a control signal in a first voltage range to the control circuit, and control the control circuit to control the function switch to open or close.

18. A touch screen for connecting a touch chip, characterized by, The common voltage line and at least two touch units are included. Each of the touch units includes a touch electrode, a function switch, and a control circuit. A first end of each of the touch electrodes is connected to the common voltage line through the function switch, and a second end of each of the touch electrodes is configured to be connected to a code signal end of the touch chip. Each of the control circuits is connected to a control end of the function switch and a connection node between the function switch and the touch electrode, and is further configured to be connected to a control signal end of the touch chip, and to control the function switch to open or close according to a control signal output by the control signal end.

19. The touch screen of claim 18, wherein, Each of the control circuits includes a first capacitor and a switch circuit. One end of the first capacitor is connected to the control end of the function switch, and the other end of the first capacitor is connected to the connection node between the function switch and the touch electrode. A first end of the switch circuit is configured to be connected to a reference voltage end of the touch chip, a second end of the switch circuit is connected to the control end of the function switch, and a third end of the switch circuit is configured to be connected to a switch signal end of the touch chip. The switch circuit is configured to open or close based on a control signal output by the switch signal end, and to control the function switch to open or close based on a reference voltage output by the reference voltage end.

20. The touch screen of claim 19, wherein, The common voltage line is connected to the common voltage end through a state switch. The reference voltage includes a first reference voltage configured to control the function switch to close. The switch circuit is configured to open based on a first control signal output by the switch signal end, and to control the function switch to close based on the first reference voltage output by the reference voltage end, so as to initialize a control end potential of the function switch. The switch circuit is further configured to close based on a second control signal output by the switch signal end, so as to maintain the function switch in a closed state and make the control end potential of the function switch follow a code potential of the touch electrode. When the state switch is in a conductive state, the common voltage line is configured to receive a common voltage output by the common voltage end, and the touch electrode is configured to receive a first code signal output by the code signal end, so as to make the touch screen enter a TSP function mode.

21. The touch screen of claim 20, wherein, The reference voltage includes a second reference voltage configured to control the switch circuit to close. The switch circuit is further configured to maintain the closed state based on the second reference voltage output by the reference voltage end when the switch circuit is closed based on the second control signal output by the switch signal end.

22. The touch screen of claim 20, wherein, At least two of the touch electrodes corresponding to the same common voltage line are configured to receive a first code signal simultaneously output by the code signal end.

23. The touch screen of claim 19, wherein, The common voltage line is connected to the common voltage end through a state switch. The reference voltage comprises a third reference voltage for controlling the function switch to open; The switch circuit is further configured to open based on a first control signal output by the switch signal terminal and based on the third reference voltage output by the reference voltage terminal. When the state switch is in the off state, the touch electrode is configured to receive a second code signal output by the code signal terminal, so as to make the touch screen enter an EMR function mode.

24. The touch screen of claim 23, wherein, The common voltage line comprises a first common voltage line connected to at least three touch electrodes. The at least three touch electrodes corresponding to the same first common voltage line are configured to receive second code signals output by the code signal terminal one by one.

25. The touch screen of claim 23, wherein, The common voltage line comprises a second common voltage line connected to two touch electrodes. The two touch electrodes corresponding to the same second common voltage line are configured to receive second code signals output by the code signal terminal simultaneously.

26. The touch screen of claim 19, wherein, The switch circuit comprises a first control switch. A first terminal of the first control switch is configured to be connected to a reference voltage terminal of the touch chip, a second terminal of the first control switch is connected to a control terminal of the function switch, and a control terminal of the first control switch is configured to be connected to a switch signal terminal of the touch chip. The first control switch is configured to open based on a first control signal output by the switch signal terminal or close based on a second control signal output by the switch signal terminal.

27. The touch screen of claim 26, wherein, The switch circuit further comprises a voltage lifting circuit connected to a connection node between the second terminal of the first control switch and the control terminal of the function switch. The voltage lifting circuit is further configured to be connected to a control signal terminal of the touch chip, for lifting a control signal in a second voltage range output by the common voltage terminal and converting it into a control signal in a first voltage range, so as to make the switch circuit open or close.

28. The touch screen of claim 27, wherein, The voltage lifting circuit comprises a second control switch, a third control switch, a fourth control switch, a fifth control switch, and a second capacitor. The second control switch, the third control switch, and the fourth control switch are connected in series, and the fourth control switch is connected to the control terminal of the function switch. The control terminal of the first control switch is configured to be connected to a first switch signal terminal of the touch chip to receive a first switch signal output by the first switch signal terminal. A first terminal of the second control switch is configured to be connected to an input terminal of the touch chip to receive a first voltage output by the input terminal, and a control terminal of the second control switch is configured to be connected to a second switch signal terminal of the touch chip to receive a second switch signal output by the second switch signal terminal. A control terminal of the third control switch is configured to be connected to a negative voltage supply terminal of the touch chip to receive a VEE voltage output by the negative voltage supply terminal. A first terminal of the fifth control switch is configured to be connected to a clock signal terminal of the touch chip, a second terminal of the fifth control switch is connected to a connection node between the third control switch and the fourth control switch, and a control terminal of the fifth control switch is connected to a control terminal of the fourth control switch. The second end of the second capacitor is connected with the second end of the fifth control switch and the control end of the fifth control switch, respectively. The voltage lifting circuit is used for controlling the voltage lifting circuit to lift voltage based on the first switch signal, the second switch signal, the first voltage, the VEE voltage and the second voltage. The first control switch is used for opening based on the first control signal outputted by the first switch signal end and closing the function switch based on the first reference voltage outputted by the reference voltage end.

29. The touch screen of claim 28, wherein, The second control switch is used for opening based on the first control signal outputted by the second switch signal end, the VDD voltage outputted by the input end and the GND voltage outputted by the clock signal end, and closing the fourth control switch and the fifth control switch.

30. The touch screen according to claim 28, wherein The first control switch is used for opening based on the first control signal outputted by the first switch signal end and opening the function switch based on the VEE voltage outputted by the reference voltage end. The second control switch is used for opening based on the first control signal outputted by the second switch signal end, transmitting the VEE voltage outputted by the input end to the node between the fourth control switch and the fifth control switch, and receiving the GND voltage outputted by the clock signal end by the fifth control switch, so that the fourth control switch is closed and the fifth control switch is opened. The first control switch is used for closing based on the second control signal outputted by the first switch signal end, the second control switch is used for closing based on the second control signal outputted by the second switch signal end, and the fifth control switch receives the VEE voltage outputted by the clock signal end, so that the fourth control switch and the fifth control switch are opened. The touch chip according to any one of claims 1-14 and the touch screen according to any one of claims 18-30 are connected.

31. An electronic device, comprising: Or, the touch device according to any one of claims 15-17 and the touch screen according to any one of claims 18-30 are connected. ​

Images