CN110737122B

CN110737122B - Liquid crystal display module, control method and electronic equipment

Info

Publication number: CN110737122B
Application number: CN201810795898.4A
Authority: CN
Inventors: 王运华
Original assignee: FocalTech Systems Ltd
Current assignee: FocalTech Systems Ltd
Priority date: 2018-07-19
Filing date: 2018-07-19
Publication date: 2022-10-25
Anticipated expiration: 2038-07-19
Also published as: TW202008345A; CN110737122A; TWI684175B

Abstract

The invention provides a liquid crystal display module, a control method and terminal equipment. The liquid crystal display module comprises a chip and a liquid crystal screen; the chip is provided with a display driving circuit and a touch detection circuit; the display driving circuit comprises a signal transmission wire, a signal selection circuit and a reference voltage generation circuit; the touch detection circuit is connected with the signal selection circuit and performs touch detection based on the display touch control timing sequence; the signal transmission wires extend from pins of the chip to the liquid crystal screen, and at least one basic common wire and at least one grid wire which are arranged in a layered mode are formed on the liquid crystal screen in a preset shape. The embodiment of the invention can enable liquid crystal screens such as STN-LCD, TN-LCD, CSTN-LCD and the like to have a touch function, and has low cost without reducing the display effect.

Description

Liquid crystal display module, control method and electronic equipment

Technical Field

The invention relates to the technical field of semiconductors, in particular to a liquid crystal display module, a control method and electronic equipment.

Background

With the continuous development of science and technology, the lcd with touch function has become a big development trend of electronic devices. However, at present, the capacitive touch technology is widely applied to TFT-LCD, and specifically, the TFT-LCD adopts an Out Cell touch method, that is, a touch screen is attached to the outer surface of the liquid crystal screen, so that the screen has both display and touch functions. The display screen is higher in manufacturing cost by means of realizing a touch function by attaching the touch screen.

Liquid crystal screens such as STN-LCD, TN-LCD, CSTN-LCD, etc. are widely used in some electronic devices due to their low cost, and their brightness and dynamic response efficiency are lower than those of TFT-LCD.

Therefore, how to enable liquid crystal screens such as STN-LCD, TN-LCD and CSTN-LCD to have a touch function without reducing the display effect is a great technical problem to be solved urgently by technical personnel in the field.

Disclosure of Invention

In view of the above, the invention provides a liquid crystal display module, a control method and an electronic device, which can enable liquid crystal screens such as STN-LCD, TN-LCD and CSTN-LCD to have a touch function, and have low cost without reducing the display effect. In order to achieve the purpose, the invention provides the following technical scheme:

a liquid crystal display module comprises a chip and a liquid crystal screen;

the chip is provided with a display driving circuit and a touch control detection circuit;

the display driving circuit comprises a signal transmission line, a signal selection circuit and a reference voltage generation circuit, wherein the signal transmission line is used for transmitting a grid signal and a public signal, the signal selection circuit gates a preset control voltage based on a display control time sequence or a display touch control time sequence, and the reference voltage generation circuit is connected with the signal selection circuit and used for providing the preset control voltage;

the touch detection circuit is connected with the signal selection circuit and is used for performing touch detection based on the display touch control timing sequence;

the signal transmission wires extend from the pins of the chip to the liquid crystal screen, and at least one basic common wire and at least one grid wire which are arranged in a layered mode are formed on the liquid crystal screen in a preset shape; the projection of the basic common wiring on the liquid crystal screen is partially or completely overlapped with the projection of the grid wiring on the liquid crystal screen;

the overlapped part of the basic common wiring and the grid wiring on the liquid crystal screen is used for displaying patterns, and the basic common wiring is also used for touch detection.

Optionally, the signal transmission trace further includes: at least one stepped public routing wire, wherein the stepped public routing wire and the basic public routing wire are arranged on the same layer on the liquid crystal display screen at a preset included angle; the advanced common trace is used for touch sensing.

Optionally, the basic common trace and the advanced common trace are disposed on a first layer of the liquid crystal display; the grid routing is arranged on the second layer of the liquid crystal display; the first layer is above the second layer.

Optionally, the projection of the advanced common trace on the liquid crystal screen is not overlapped with the projection of the basic common trace on the liquid crystal screen.

Optionally, the basic common trace is used to transmit a common signal, and the gate trace is used to transmit a gate signal; or, the basic common line is used for transmitting a gate signal, and the gate line is used for transmitting a common signal.

A liquid crystal display module control method is applied to the liquid crystal display module; the method comprises the following steps:

alternately executing a display control time sequence or a display touch control time sequence according to a preset rule to gate a preset control voltage;

detecting whether a touch action exists or not through the touch detection circuit in the display touch control time sequence section;

and if the touch action is detected, determining the touch position of the touch action according to the signal output by the touch detection circuit.

Optionally, determining the position of the touch action according to the signal output by the touch detection circuit includes determining the position of the touch action in the first direction according to a signal value generated by the signal on the at least one basic common trace.

Optionally, the signal transmission lines of the liquid crystal display further include at least one stepped common line, and the stepped common line is arranged on the same layer as the basic common line on the liquid crystal display at a preset included angle; the advanced common wiring is used for touch detection;

the determining the position of the touch action according to the signal output by the touch detection circuit further includes: and judging the position of the touch action in the second direction according to a signal value generated by the signal on the advanced common wiring.

Optionally, the position of the touch action on the liquid crystal display screen is confirmed according to the position in the first direction and the position in the second direction.

Optionally, the routing transmission of the gate signal and the common signal by the signal transmission line includes:

a first transmission mode: the basic common wiring is used for transmitting common signals, and the grid wiring is used for transmitting grid signals; a second transmission mode: the basic common wiring is used for transmitting grid signals, and the grid wiring is used for transmitting common signals; the first transmission mode and the second transmission mode are alternately executed.

An electronic device comprises an electronic device body and the liquid crystal display screen. Compared with the prior art, the technical scheme provided by the invention has the following advantages:

the invention provides a liquid crystal display module, a control method and terminal equipment, wherein the liquid crystal display module comprises the following components: the liquid crystal display comprises a chip and a liquid crystal screen; the chip is provided with a display driving circuit and a touch detection circuit; the display driving circuit comprises a signal transmission line, a signal selection circuit and a reference voltage generation circuit, wherein the signal transmission line is used for transmitting a grid signal and a public signal, the signal selection circuit gates a preset control voltage based on a display control time sequence or a display touch control time sequence, and the reference voltage generation circuit is connected with the signal selection circuit and used for providing the preset control voltage; the touch detection circuit is connected with the signal selection circuit and is used for performing touch detection based on the display touch control timing sequence; the signal transmission wires extend from pins of the chip to the liquid crystal screen, and at least one basic common wire and at least one grid wire which are arranged in a layered mode are formed on the liquid crystal screen in a preset shape; the projection of the basic common wiring on the liquid crystal screen is partially or completely overlapped with the projection of the grid wiring on the liquid crystal screen. Therefore, the liquid crystal display module provided by the invention can enable liquid crystal screens such as STN-LCD, TN-LCD and CSTN-LCD to have a touch function, and is low in cost without reducing the display effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a diagram of driving waveforms for a prior art STN-LCD;

FIG. 2 is a schematic diagram of waveforms of FIG. 1 plotted together;

FIG. 3 is a schematic diagram of a prior art STN-LCD display driving circuit;

fig. 4 is a schematic diagram illustrating a driving principle of the touch circuit 200;

fig. 5 is a schematic diagram of a touch display circuit in a liquid crystal display module according to an embodiment of the invention;

fig. 6 is another schematic diagram of a touch display circuit in a liquid crystal display module according to an embodiment of the disclosure;

fig. 7 is another schematic diagram of a touch display circuit in a liquid crystal display module according to an embodiment of the invention;

fig. 8 is a schematic diagram illustrating touch control performed on a liquid crystal display according to an embodiment of the present invention;

fig. 9 is a schematic view illustrating a touch on a liquid crystal display according to another embodiment of the present invention;

FIG. 10 is a schematic diagram of a touch-generated voltage distribution in FIG. 9 according to an embodiment of the present invention;

FIG. 11 is a flowchart illustrating a method for controlling a liquid crystal display module according to an embodiment of the present invention;

fig. 12a is a schematic view of a trace pattern on a liquid crystal display according to an embodiment of the invention;

FIG. 12b is a schematic view of another trace pattern on a liquid crystal display panel according to an embodiment of the present invention;

fig. 13 is a schematic view of a trace pattern on a liquid crystal display according to another embodiment of the invention;

fig. 14 is a schematic diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In combination with the background art, some conventional liquid crystal panels (such as STN-LCD, TN-LCD, CSTN-LCD, etc.) have failed to implement touch functionality, and the inventors consider that these liquid crystal panels are generally applied to low-cost electronic devices. In addition, in the prior art, a touch screen module (including a touch screen and a touch chip) is attached to the liquid crystal screens, or such liquid crystal screens can have a touch function. However, the screen-attaching method will reduce the display effect of the original liquid crystal screen and greatly increase the cost, which is contrary to the low-cost concept.

Based on this, taking the STN-LCD as an example, the inventor combines the display principle of the current STN-LCD and realizes the touch function of the STN-LCD display screen in a manner of not adding a touch screen. As shown in fig. 1, for the STN-LCD, it is generally driven by using a driving waveform similar to a Capacitive Touch Panel (CTP), wherein waveforms symmetrical to each other are selected in an ODD FRAME (ODD FRAME) and an EVEN FRAME (EVEN FRAME) to eliminate the influence of a dc component on a signal.

Specifically, taking a waveform with a control voltage of 6 levels as an example, when each common voltage is in an inactive state, the current common voltage is set to be the second preset voltage V1, and when the common voltage is in an active state, the current common voltage is set to be the sixth preset voltage V5. And then signal change is carried out between the common voltages transmitted by different basic common wires according to a certain time interval.

In the present embodiment, the gate voltage is set to have the second predetermined voltage V1 as the middle data, the third predetermined voltage V2 as the high voltage of the gate voltage, and the first predetermined voltage V0 as the low voltage of the gate voltage.

The waveforms of the common voltage and the gate voltage in fig. 1 are plotted at the same time, and a waveform curve as shown in fig. 2 is presented, in which a black bold line is a waveform of the common voltage, and a diamond structure is a waveform range of the gate voltage, that is, the gate voltage is the third preset voltage V2 or the first preset voltage V0.

On the basis of the above embodiment, the voltage selection for the common voltage can be realized by the driving circuit as shown in fig. 3, for example, when the switch 31 is closed, the common voltage COM (i) is the sixth preset voltage V5, and when the switch 33 is closed, the common voltage COM (i) is the second preset voltage V1.

Specifically, each basic common trace COM (i) corresponds to one switch group 111 (i), where i is an integer greater than or equal to 1. Correspondingly, each gate line SEG (j) corresponds to one switch group 121 (j), wherein j is also an integer greater than or equal to 1, then the on and off states of the switches in the switch group 111 (i) are controlled through a time sequence 112 (i), and the on and off states of the switches in the switch group 121 (j) are controlled through a time sequence 122 (j), so that the corresponding common voltage and the gate voltage are output.

Illustratively, referring to fig. 3, the switch group 111 (i) includes a switch 31, a switch 32, a switch 33, and a switch 34, specifically, one end of the switch 31 is connected to a sixth preset voltage V5, one end of the switch 32 is connected to a fifth preset voltage V4, one end of the switch 33 is connected to a second preset voltage V1, one end of the switch 34 is connected to a first preset voltage V0, and the other end of the switch 31, the other end of the switch 32, the other end of the switch 33, and the other end of the switch 34 are all connected to the basic common trace COM (i).

The switch group 121 (j) includes a switch 35, a switch 36, a switch 37, and a switch 38, specifically, one end of the switch 35 is connected to a sixth preset voltage V5, one end of the switch 36 is connected to a fourth preset voltage V3, one end of the switch 37 is connected to a third preset voltage V2, one end of the switch 38 is connected to a first preset voltage V0, and the other end of the switch 35, the other end of the switch 36, the other end of the switch 37, and the other end of the switch 38 are all connected to a gate trace SEG (j).

Fig. 3 also provides a reference voltage generating circuit for generating a predetermined voltage. For example, a desired signal value is obtained by a resistor divider circuit formed by the resistor 11, the resistor 12, the resistor 13, the resistor 14, and the resistor 15, and the voltages V0, V1, V2, V3, V4, and V5 are supplied by the operational amplifier 21, the operational amplifier 22, the operational amplifier 23, and the operational amplifier 24.

Besides, it should be noted that, in this embodiment, the circuit shown in 101 is located inside the chip, and the signal transmission trace 500 shown in 102 is located outside the chip (on the liquid crystal display); that is, the signal transmission traces shown in 102 are connected to the pins of the chip, and extend from the pins of the chip to the liquid crystal panel, and the trace pattern shown in 102 is formed on the liquid crystal panel.

On the basis, the inventor combines the driving principle of the touch circuit 200 as shown in fig. 4, and when the first timing is performed, the control switch 61 and the switch 62 are both opened, and the control switch 64 is closed. One end of the switch 64 is connected to the second preset voltage V1, the other end of the switch 64 is connected to the non-inverting input terminal 41 of the amplifier 50, one end of the switch 60 is connected to the inverting input terminal of the amplifier 50, and the other end of the switch 60 is connected to the output terminal of the touch circuit.

At this time, the switch 60 is closed, the amplifier 50 performs an auto clear operation, the charge amount Q (C51) =0 on the capacitor 51, and the output terminal voltage Vo = V1 of the touch circuit.

The

switches

71 and 73 are closed, the switch 72 is opened, the upper end of the capacitor 70 is connected to the voltage VDD, and the lower end is grounded to store the predetermined charge.

Meanwhile, the basic common line COM is connected to a sixth preset voltage V5 to perform a precharge operation. It can be seen that the sum of the charge amounts of the three circuit parts in fig. 4 is Q1=0+ c70 + vdd + Cself + v5, where Cself is the self-capacitance of the common electrode.

When in the second timing, both the control switch 61 and the switch 62 are closed.

At this time, the switch 60 is turned off, and the amplifier 50 performs a detection operation.

The

switches

71 and 73 are opened, the switch 72 is closed, and the lower end of the capacitor 70 is connected to the voltage VDD.

At this time, the potential of COM is maintained at the second predetermined voltage V1 by the virtual ground of the amplifier 50.

It can be seen that the sum of the charge amounts of the three-part circuit in fig. 4 is Q2= C51 (V1-Vo) + C70 (V1-VDD) + Cself V1.

Since Q2= Q1, the output voltage Vo = V1+ C70/C51 (V1-2 vdd) + Cself/C51 (V1-V5) of the touch circuit. Cself is original self-capacitance, and when a finger touches the device, capacitance change Cfinger is brought, and Cself is changed into Cself' = Cself + Cfinger, which is not described herein again.

Therefore, based on the circuit, the detection of the touch event can be realized by detecting the change of the voltage at the output end of the amplifier.

The inventor integrates the touch circuit and the driving circuit into a chip, and the chip is called a touch display control circuit. As shown in fig. 5, the liquid crystal display module provided by the embodiment of the invention includes a chip 101 and signal transmission trace extending portions 102 on a liquid crystal screen. The touch display control circuit in the chip 101 includes: a display driving circuit 501 and a touch detection circuit 502.

It should be noted that, in this embodiment, the circuit shown in 101 is located inside the chip, and the signal transmission trace 500 shown in 102 is located outside the chip (on the liquid crystal display); that is, the signal transmission traces shown in 102 are connected to the pins of the chip, and extend from the pins of the chip to the liquid crystal panel, and the trace pattern shown in 102 is formed on the liquid crystal panel. It is understood that the present embodiment is described by combining the signal transmission traces shown in the portion 102 with the display driving circuit 501 for convenience of description.

The display driving circuit 501 includes a signal transmission trace 500, a signal selection circuit (504 and 121 (j)), and a reference voltage generation circuit 503, where the signal transmission trace 500 is used to transmit a gate signal and a common signal, the signal selection circuit (504 and 121 (j)) gates a preset control voltage based on a display control timing 122 (j) or a display touch control timing 132 (i), and the reference voltage generation circuit 503 is connected to the signal selection circuit (504 and 121 (j)) and is used to provide the preset control voltage. The touch detection circuit 502 is connected to the signal selection circuit 504, and performs touch detection based on a display touch control timing.

Therefore, the touch display control circuit combines the display driving circuit and the touch detection circuit, so that the liquid crystal display has a touch function without reducing the display effect.

Specifically, the signal selection circuit provided in this embodiment has a plurality of implementation manners, and referring to fig. 5, the signal selection circuit provided in this embodiment includes:

a gate signal selection sub-circuit 121 (j) connected to the reference voltage generation circuit 503, gating a target gate voltage based on the display control timing 122 (j), and transmitting the target gate voltage to a gate trace SEG among the signal transmission traces;

the common electrode signal selection sub-circuit 504 is connected to the reference voltage generation circuit 503, gates a target common voltage based on the display control timing 122 (j) or the display touch control timing 132 (i), and transmits the target common voltage to the basic common line COM in the signal transmission line 500.

It should be noted that, as shown in fig. 5, the touch display circuit provided in this embodiment includes a plurality of touch detection circuits 502, specifically, each basic common trace COM (i) is connected to one common electrode signal selection sub-circuit 504, and each common electrode signal selection sub-circuit 504 is connected to one touch detection circuit 502.

That is, in this embodiment, the number of the common electrode signal selection sub-circuits 504 is the same as the number of the touch detection circuits 502, and the common electrode signal selection sub-circuits 504 and the touch detection circuits 502 together constitute the first circuit 131 (i).

On the basis of the foregoing embodiments, the embodiment of the present invention further provides a specific implementation structure of the common electrode signal selection sub-circuit 504 and the gate signal selection sub-circuit 121 (j), wherein the common electrode signal selection sub-circuit 504 includes a first switch 31, a second switch 32, a third switch 33, and a fourth switch 34, and the gate signal selection sub-circuit 121 (j) includes a fifth switch 35, a sixth switch 36, a seventh switch 37, and an eighth switch 38;

specifically, the first end of the first switch 31, the first end of the second switch 32, the first end of the third switch 33, and the first end of the fourth switch 34 are all connected to the same basic common trace COM (i);

a second end of the first switch 31, a second end of the second switch 32, a second end of the third switch 33, and a second end of the fourth switch 34 are sequentially connected to the sixth preset voltage V5, the fifth preset voltage V4, the second preset voltage V1, and the first preset voltage V0;

the control end of the first switch 31, the control end of the second switch 32, the control end of the third switch 33, and the control end of the fourth switch 34 are all connected to the display control timing 122 (j) or the display touch control timing 132 (i);

a first end of the fifth switch 35, a first end of the sixth switch 36, a first end of the seventh switch 37, and a first end of the eighth switch 38 are all connected to the same gate trace SEG (j);

the second end of the fifth switch 35, the second end of the sixth switch 36, the second end of the seventh switch 37, and the second end of the eighth switch 38 are sequentially connected to the sixth preset voltage V5, the fourth preset voltage V3, the third preset voltage V2, and the first preset voltage V0.

The control end of the fifth switch, the control end of the sixth switch, the control end of the seventh switch, and the control end of the eighth switch are all connected to the display control timing sequence 122 (j).

It should be noted that, in the present embodiment, there are a plurality of touch detection circuits. In addition, there may be only one touch detection circuit, for example, in fig. 6, each basic common trace COM (i) is connected to one common electrode signal selection sub-circuit 601, and a plurality of common electrode signal selection sub-circuits 601 are all connected to the same touch detection circuit 602. Therefore, the number of touch detection circuits 602 can be reduced, and the size of the liquid crystal display module is reduced.

Specifically, the embodiment of the present invention further provides a specific implementation structure of the common electrode signal selection sub-circuit 601 and the gate signal selection sub-circuit, wherein the common electrode signal selection sub-circuit 601 includes a ninth switch 31', a tenth switch 32', an eleventh switch 33', a twelfth switch 34', and a thirteenth switch 35', and the gate signal selection sub-circuit includes a fourteenth switch 36', a fifteenth switch 37', a sixteenth switch 38', and a seventeenth switch 39'.

Specifically, the first end of the ninth switch 31', the first end of the tenth switch 32', the first end of the eleventh switch 33', the first end of the twelfth switch 34' and the first end of the thirteenth switch 35' are all connected to the same basic common trace COM (i);

a second end of the ninth switch 31', a second end of the tenth switch 32', a second end of the eleventh switch 33 'and a second end of the twelfth switch 34' are sequentially connected to the sixth preset voltage V5, the fifth preset voltage V4, the second preset voltage V1 and the first preset voltage V0;

the control end of the ninth switch 31', the control end of the tenth switch 32', the control end of the eleventh switch 33 'and the control end of the twelfth switch 34' are all connected to the display control timing sequence or the display touch control timing sequence;

a second end of the thirteenth switch 35' is connected to the touch detection circuit 602;

a first end of the fourteenth switch 36', a first end of the fifteenth switch 37', a first end of the sixteenth switch 38', and a first end of the seventeenth switch 39' are all connected to the same gate trace SEG (j);

a second end of the fourteenth switch 36', a second end of the fifteenth switch 37', a second end of the sixteenth switch 38', and a second end of the seventeenth switch 39' are sequentially connected to the sixth preset voltage V5, the fourth preset voltage V3, the third preset voltage V2, and the first preset voltage V0.

The control end of the fourteenth switch 36', the control end of the fifteenth switch 37', the control end of the sixteenth switch 38 'and the control end of the seventeenth switch 39' are all connected to the display control sequence.

On the basis of the foregoing embodiments, an embodiment of the present invention further provides a specific implementation structure of a signal selection circuit, as shown in fig. 7, the signal selection circuit 151 (i) includes a plurality of switches, and a control end of each switch can be connected to the display control timing sequence or the display touch control timing sequence to gate a preset control voltage to the signal transmission trace 500.

Specifically, the signal selection circuit includes: an eighteenth switch 311, a nineteenth switch 321, a twentieth switch 331, a twenty-first switch 341, a twenty-second switch 351, a twentieth switch 361, and a twenty-fourth switch 371;

the first end of the eighteenth switch 311, the first end of the nineteenth switch 321, the first end of the twentieth switch 331, the first end of the twenty-first switch 341, the first end of the twenty-second switch 351, the first end of the twentieth switch 361, and the first end of the twenty-fourth switch 371 are all connected to the same basic common trace COM (i) or the same gate trace SEG (j);

a second end of the eighteenth switch 311, a second end of the nineteenth switch 321, a second end of the twentieth switch 331, a second end of the twenty-first switch 341, a second end of the twenty-second switch 351, a second end of the twentieth switch 361, and a second end of the twenty-fourth switch 371 are sequentially connected to the sixth preset voltage V5, the fifth preset voltage V4, the fourth preset voltage V3, the third preset voltage V2, the second preset voltage V1, and the first preset voltage V0;

the control end of the eighteenth switch 311, the control end of the nineteenth switch 321, the control end of the twentieth switch 331, the control end of the twenty-first switch 341, the control end of the twenty-second switch 351, and the control end of the twentieth switch 361 are all connected to the display control timing or the display touch control timing 152 (i);

a second end of the twenty-fourth switch 371 is connected to the touch detection circuit 702.

Similarly, in the present embodiment, each signal selection circuit 151 (i) may correspond to one touch detection circuit 702, or a plurality of signal selection circuits 151 (i) correspond to the same touch detection circuit 702, such that:

the number of the touch detection circuits 702 is plural, each of the basic common traces COM (i) is connected to one of the signal selection circuits 151 (i), and each of the signal selection circuits 151 (i) is connected to any one of the touch detection circuits 702.

Or the like, or, alternatively,

each basic common trace COM (i) is connected to one signal selection circuit 151 (i), and a plurality of signal selection circuits 151 (i) are connected to the same touch detection circuit 702.

On the basis of the foregoing embodiments, with reference to fig. 5 to fig. 7, an embodiment of the present invention further provides a specific implementation structure of a reference voltage generating circuit (503 or 603), including a first resistor 11, a second resistor 12, a third resistor 13, a fourth resistor 14, a fifth resistor 15, a first amplifier 21, a second amplifier 22, a third amplifier 23, and a fourth amplifier 24.

Specifically, a first end of the first resistor 11 is used as an output end of the first preset voltage V0;

a second end of the first resistor 11 is connected to a non-inverting input terminal of the first amplifier 21 and a first end of the second resistor 12, respectively, and an inverting input terminal of the first amplifier 21 is connected to an output terminal of the first amplifier 21 and serves as an output terminal of the second preset voltage V1;

a second end of the second resistor 12 is connected to a non-inverting input terminal of the second amplifier 22 and a first end of the third resistor 13, respectively, and an inverting input terminal of the second amplifier 22 is connected to an output terminal of the second amplifier 22 and serves as an output terminal of the third preset voltage V2;

a second end of the third resistor 13 is connected to a non-inverting input terminal of the third amplifier 23 and a first end of the fourth resistor 14, respectively, and an inverting input terminal of the third amplifier 23 is connected to an output terminal of the third amplifier 23 and serves as an output terminal of the fourth preset voltage V3;

a second end of the fourth resistor 14 is connected to a non-inverting input terminal of the fourth amplifier 24 and a first end of the fifth resistor 15, respectively, and an inverting input terminal of the fourth amplifier 24 is connected to an output terminal of the fourth amplifier 24 and serves as an output terminal of the fifth preset voltage V4;

the required signal value can be obtained by the resistor voltage dividing circuit formed by the resistor 11, the resistor 12, the resistor 13, the resistor 14 and the resistor 15, and the voltages of V0, V1, V2, V3, V4 and V5 can be provided by the operational amplifier 21, the operational amplifier 22, the operational amplifier 23 and the operational amplifier 24.

Specifically, an embodiment of the present invention further provides a specific implementation circuit of a touch detection circuit, where the touch detection circuit includes: an amplifier and a plurality of switches;

the amplifier is used for detecting the change value of the self-capacitance of the common electrode and outputting a signal corresponding to the change value of the self-capacitance.

Specifically, with reference to fig. 5, the touch detection circuit may include: a first capacitor 51, a second capacitor 52, a fifth amplifier 50, a twenty-fifth switch 60, a twenty-sixth switch 61, a twenty-seventh switch 62, a twenty-eighteenth switch 63, and a twenty-ninth switch 64.

Specifically, two ends of the twenty-fifth switch 60 and the first capacitor 51 are connected in parallel to the inverting input end and the output end of the fifth amplifier 50, and the output end of the fifth amplifier 50 is used as the output end of the touch detection circuit 502;

the inverting input terminal of the fifth amplifier 50 is connected to the signal selection circuit 131 (i) through a twenty-sixth switch 61, and the signal selection circuit 131 (i) is connected to the second capacitor 52 through a twenty-seventh switch 62;

the non-inverting input terminal of the fifth amplifier 50 is connected to the fifth preset voltage V4 through the twenty-eighth switch 63, and is connected to the second preset voltage V1 through the twenty-ninth switch 64.

With the above circuit structure, the operation principle of the present solution will now be described as follows:

and in a display time sequence section, based on the display control time sequence, controlling the display driving circuit to be in an open state, controlling the touch detection circuit to be in an isolation and automatic correction state, and gating a preset control voltage so that the display driving circuit outputs the preset control voltage to the signal transmission wiring.

Specifically, the first switch 31 may be controlled to be closed, so that the basic common trace COM (i) is connected to the sixth preset voltage V5, that is, the common voltage COM in the active state is V5 at this time, and the twenty-seventh switch 62 is controlled to be closed, so that the second capacitor 52 stores the preset charge. The twenty-ninth switch 64 is controlled to be closed, so that the second preset voltage V1 is connected to the non-inverting input terminal of the fifth amplifier 50, and the fifth amplifier 50 performs an automatic zero clearing operation.

In the display touch control time sequence, the touch control detection circuit 502 is controlled to perform touch control detection based on the display touch control time sequence.

Specifically, the display touch timing section includes a first stage and a second stage;

in the first stage, the display driving circuit 501 is in an on state, and the touch detection circuit 502 is in an isolated and self-calibrated state. At this time, the inverting input terminal of the fifth amplifier 50 in the touch detection circuit 502 is connected to the output terminal, so that the output terminal of the fifth amplifier 50 is maintained at a specific signal value, such as the second preset voltage V1.

In the second stage, the touch detection circuit 502 is in a detection state. At this time, the common voltage COM (i) is connected to the inverting input terminal of the fifth amplifier 50, and due to the virtual ground effect when the fifth amplifier 50 is operating normally, the voltage at the inverting input terminal of the fifth amplifier 50 is the same as the voltage at the non-inverting input terminal, and at this time, the non-inverting input terminal of the fifth amplifier 50 is connected to an appropriate potential, so that the potential on the basic common line COM (i) can be maintained at the above-mentioned specific signal value, such as the second preset voltage V1, and at this time, the normal display function can be maintained and the capacitance detection function can be performed.

Illustratively, the first switch 31, the second switch 32, the third switch 33, the fourth switch 34, the fifth switch 35, the sixth switch 36, the seventh switch 37, and the eighth switch 38 may be controlled to be turned off, and the twenty-fifth switch 60, the twenty-sixth switch 61, the twenty-seventh switch 62, and the twenty-ninth switch 64 may be controlled to be turned on, so that the touch detection circuit outputs the target voltage based on the touch action.

It should be noted that, in each embodiment of the present invention, the circuit shown in 101 is located inside the chip, and the signal transmission trace shown in 102 is located outside the chip (on the liquid crystal display); that is, the signal transmission traces shown in 102 are connected to the pins of the chip, and extend from the pins of the chip to the liquid crystal panel, and the trace pattern shown in 102 is formed on the liquid crystal panel. It is understood that the signal transmission traces shown in the portion 102 are combined with the display driving circuit 501 in the present embodiment for convenience of description.

Therefore, the touch display control circuit combines the display driving circuit and the touch detection circuit, enables the liquid crystal screen to have a touch function, is low in cost and does not reduce the display effect because a mode of attaching the touch screen is not used, and is suitable for liquid crystal screens such as STN-LCDs, TN-LCDs, CSTN-LCDs and the like.

Please refer to the portion 102 in the embodiment corresponding to any of fig. 5, 6, and 7, that is, the extending portion of the signal transmission trace on the liquid crystal display. It can be seen that, in these embodiments, on the liquid crystal screen, at least one basic common trace COM and at least one gate trace SEG are arranged in a layered manner, there is an overlapping portion between the projection of the basic common trace on the liquid crystal screen and the projection of the gate trace on the liquid crystal screen, and the arrangement manner of the plurality of basic common traces COM and the plurality of gate traces SEG forms a dot-matrix liquid crystal screen. Of course, it is understood that the projections of the basic common trace COM and the gate trace SEG on the liquid crystal panel may also be all overlapped. The overlapped part of the basic common line COM and the gate line SEG on the liquid crystal screen is used for displaying patterns, and the basic common line COM is also used for touch detection.

Referring to fig. 8, the touch position of the touch operation is determined according to the signal output by the touch detection circuit by taking an example of arrangement of 15 basic common lines (com.01, com.02, com.03, com.04, com.05, com.06, com.07, com.08, com.09, com.10, COM11, COM12, com.13, com.14, and com.15) and 5 gate lines (seg.1, seg.2, seg.3, seg.4, and seg.5). It can be seen that the touch of the user generates a certain signal value on com.05, com.06, com.07, com.08, thereby determining that the position of the touch action in the X direction occurs on com.05, com.06, com.07, com.08, i.e., the positions 801,802, and 803 in the figure.

Therefore, the touch position of the user can be identified in a single direction through the method.

It should be noted that, in the embodiment of the present invention, the basic common trace is used to transmit a common signal, and the gate trace is used to transmit a gate signal; in specific implementation, the basic common trace can also be used for transmitting gate signals, and the gate trace can also transmit common signals, that is, signals transmitted by the two traces are interchanged. The two-dimensional touch detection function can be realized by the alternate execution.

Referring back to fig. 8, since the generated signal is the same regardless of whether the touch position of the user occurs at 801,802 or 803, the touch position of the user in the Y direction cannot be further identified.

Therefore, referring to fig. 9, in the embodiment of the present invention, the design of the common trace is further improved, and a stepped common trace com.0 is added, the stepped common trace and the basic common trace are arranged on the same layer on the liquid crystal screen at a preset included angle, and the projection of the com.0 on the liquid crystal screen does not overlap with the projection of the basic common trace on the liquid crystal screen; the advanced common trace com.0 is also used for touch detection. It should be noted that, in a specific implementation, an included angle between the advanced common line com.0 and the basic common line may be set at a preset included angle according to a specific requirement, and the two are not parallel. In fig. 9, com.0 is disposed perpendicular to the basic common trace, which is one embodiment.

Fig. 10 shows a signal condition detected after the trace layout of fig. 9 is adopted, please refer to fig. 9 and fig. 10, and determine the touch position of the touch action according to the signal output by the touch detection circuit. It can be seen that a touch by a user causes the signal to produce a signal value not only on com.05, com.06, com.07 and com.08, but also on the advanced common trace com.0. It can be understood that, if the touch position of the user is closer to com.0, the signal value generated at com.0 is larger, whereas, if the touch position of the user is farther from com.0, the signal value generated at com.0 is smaller, and the touch position of the user in the Y direction is determined according to the signal values V901, V902, and V903. And then, the signal values of the signals on the COM.05, the COM.06, the COM.07 and the COM.08 are combined to judge the touch position of the user in the X direction, so that the accurate touch position of the user on the liquid crystal screen is determined to be 901,902 or 903.

Further, after the finger touch position is determined, the embodiment may further determine a touch instruction corresponding to the touch action based on a plurality of touch positions.

For example, when the touch position of the finger on the display screen is detected to move rightward in sequence within a preset time, the touch position can be set to a "right sliding" action.

Correspondingly, referring to fig. 11, the embodiment of the invention further provides a control method for the liquid crystal display module. The method comprises the following steps: s11, alternately executing a display control time sequence or a display touch control time sequence according to a preset rule to gate a preset control voltage; s12, detecting whether a touch action exists through the touch detection circuit in the display touch control timing section; and S13, if the touch action is detected, determining the touch position of the touch action according to the signal output by the touch detection circuit.

Determining the position of the touch action according to the signal output by the touch detection circuit, wherein the position of the touch action in a first direction is judged according to a signal value generated by the signal on the at least one basic common line;

judging the position of the touch action in a second direction according to a signal value generated by the signal on the advanced common wiring;

and confirming the position of the touch action on the liquid crystal display screen according to the position in the first direction and the position in the second direction.

It is understood that, in the above embodiments of the present invention, the signal is a voltage, and the signal value is a voltage value; of course, the signal may also be a current, and correspondingly, the signal value may also be a current value.

The signal transmission routing transmission gate signal and common signal include: the first transmission mode is as follows: the basic common wiring is used for transmitting common signals, and the grid wiring is used for transmitting grid signals;

a second transmission mode: the basic common wiring is used for transmitting grid signals, and the grid wiring is used for transmitting common signals; the first transmission mode and the second transmission mode are executed alternately, and then the two-dimensional touch detection function can be realized.

The above examples of the control method correspond to the specific embodiments of the liquid crystal display module, and are not described again.

In addition, the common trace can be set to be in a preset shape in the embodiment, so as to realize the functions of specific display and touch control.

As shown in fig. 12a and 12b, the liquid crystal panel provided in this embodiment may have the common traces and the gate traces arranged in the form of icons. In fig. 12a, a common trace COM is disposed corresponding to four gate traces seg.1, seg.2, seg.3, and seg.4, so that the common trace COM can be used as a touch key. In fig. 12b, four common lines com.1, com.2, com.3, and com.4 may also be disposed corresponding to one gate line SEG, so that four independent touch keys are obtained in addition to four icons respectively in the shape of a circle, a rectangle, a triangle, and a cross.

Therefore, the embodiment of the invention can greatly or even completely replace the externally hung keys of the liquid crystal screens such as STN-LCD, TN-LCD, CSTN-LCD and the like.

Referring to fig. 13, the common traces and the gate traces are now set to be the digital display pattern "8" for example, there may be a plurality of arrangements, for example, the left portion of fig. 13 is configured by using a common trace c.0 and 7 gate traces s.1, s.2, s.3, s.4, s.5, s.6, and s.7, and the whole number "8" is a touch key except for the original display function. The middle part and the right part of fig. 13 are configured by three common wires c.1, c.2 and c.3 in combination with three gate wires s.1, s.2 and s.3. In addition to the original display function, the number "8" in the middle of fig. 13 can form three touch keys, i.e., upper, middle and lower, because of different arrangements; the numeral "8" on the right portion of fig. 13 may form three touch keys on the left, middle and right.

Therefore, in practical application, a multi-level touch function can be arranged, for example, the increase and decrease of digital contents can be adjusted by the up-down left-right sliding detection, and the externally-hung keys of the existing liquid crystal screens such as STN-LCD, TN-LCD and CSTN-LCD can be greatly and even completely replaced.

It should be noted that, in the embodiments corresponding to fig. 12a, fig. 12b and fig. 13, the common traces and the gate traces are still disposed in a layered manner, which indicates that they are not disposed in the same layer of the liquid crystal panel but are expanded for convenience of description.

On the basis of the above embodiments, as shown in fig. 14, an embodiment of the invention further provides an electronic device, which includes an electronic device body and the above liquid crystal display module.

In summary, embodiments of the present invention provide a liquid crystal display module, a control method, and an electronic device, which enable liquid crystal displays such as STN-LCD, TN-LCD, and CSTN-LCD to have a touch function, and are low in cost and do not reduce the display effect because no touch screen needs to be hung.

In the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid crystal display module is characterized by comprising a chip and a liquid crystal screen;

the liquid crystal screen is a passive matrix type liquid crystal display screen, and the passive matrix type liquid crystal display screen comprises an STN-LCD, a TN-LCD or a CSTN-LCD;

the chip is provided with a display driving circuit and a touch detection circuit;

the display driving circuit comprises a signal transmission wire, a signal selection circuit and a reference voltage generation circuit, wherein the signal transmission wire is used for transmitting a grid signal and a public signal, the signal selection circuit gates a preset control voltage based on a display control time sequence or a display touch control time sequence, and the reference voltage generation circuit is connected with the signal selection circuit and used for providing the preset control voltage;

2. The LCD module of claim 1, wherein the signal transmission traces further comprise: at least one advanced common line, wherein the advanced common line and the basic common line are arranged on the same layer on the liquid crystal display at a preset included angle; the advanced common line is used for touch detection.

3. The LCD module according to claim 2, wherein the basic common traces and the advanced common traces are disposed on a first layer of the LCD panel; the grid routing is arranged on the second layer of the liquid crystal display; the first layer is above the second layer.

4. The LCD module as claimed in claim 2, wherein the projection of the advanced common traces on the LCD screen has no overlap with the projection of the basic common traces on the LCD screen.

5. The LCD module of claim 1, wherein the basic common traces are used for transmitting common signals, and the gate traces are used for transmitting gate signals; or, the basic common line is used for transmitting a gate signal, and the gate line is used for transmitting a common signal.

6. A liquid crystal display module control method, characterized in that, the liquid crystal display module is the liquid crystal display module of claim 1; the method comprises the following steps:

alternately executing a display control time sequence or gating a preset control voltage according to a preset rule;

7. The method according to claim 6, wherein determining the position of the touch according to the signal output by the touch detection circuit comprises determining the position of the touch in a first direction according to a signal value generated by the signal on the at least one basic common trace.

8. The method according to claim 7, wherein the signal transmission traces of the lcd module further comprise at least one advanced common trace, and the advanced common trace is disposed on the same layer as the basic common trace on the lcd panel at a predetermined included angle; the advanced common wiring is used for touch detection;

9. The method of claim 8, wherein the location of the touch action on the liquid crystal display is confirmed according to the location in the first direction and the location in the second direction.

10. The method of claim 6, wherein the signal transmission trace transmits the gate signal and the common signal comprises:

a first transmission mode: the basic common wiring is used for transmitting common signals, and the grid wiring is used for transmitting grid signals;

a second transmission mode: the basic common wiring is used for transmitting grid signals, and the grid wiring is used for transmitting common signals;

the first transmission mode and the second transmission mode are alternately executed.

11. An electronic device comprising an electronic device body and the liquid crystal display module according to any one of claims 1 to 5.