A display device

Abstract

A display device comprises a display panel, a power management integrated circuit and a source driving circuit, a common voltage module outside the display panel and the power management integrated circuit; the source driving circuit is electrically connected with the display panel and the power management integrated circuit respectively; the common voltage module is used for providing a common voltage signal for a common electrode of the display panel, and the common voltage signal is at the same potential as a shell of the display device; the power management integrated circuit is used for providing a positive voltage source and a negative voltage source for the source driving circuit; the source driving circuit is used for generating analog data signals of positive polarity or negative polarity for the display panel, and the analog data signals of positive polarity use the positive voltage source as a power source, and the analog data signals of negative polarity use the negative voltage source as a power source.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more particularly to a display device. Background Technology

[0002] Liquid crystal display products mainly consist of a liquid crystal display panel, a time controller (TCON), a source driver circuit, a power management integrated circuit (PMIC), and a backlight.

[0003] Currently, the source drive circuits used in large-size LCD products are mostly of the fully positive voltage (AVDD) or fully positive half voltage (HAVDD) type. A characteristic of LCD panels is that when the bright and dark images alternate continuously, the human eye perceives a flickering phenomenon. This is because the LCD panel controls the deflection of the liquid crystal with voltage, and the liquid crystal is driven by AC. If the reference voltage (VCOM) for the liquid crystal deflection is not properly adjusted, the voltages of two consecutive frames will be unequal, resulting in alternating bright and dark images and flickering.

[0004] In existing technologies, the flicker value is typically minimized by adjusting the liquid crystal deflection reference voltage (usually denoted as VCOM voltage), which is generally output by the PMIC. However, in large-size display products, the VCOM electrode is generally located on the color filter substrate side of the liquid crystal display panel. Since the source drive circuit generally uses a HAVDD architecture, the VCOM voltage is typically set at around 7-8V. During reliability high and low temperature tests or other tests that generate moisture, moisture can enter between the VCOM electrode (Vcom ≒ 7V) and the GND (0V) of the entire liquid crystal display product. This moisture can then cause electrochemical corrosion in the return circuit. Summary of the Invention

[0005] This disclosure provides a display device to solve the aforementioned problems existing in the prior art.

[0006] In a first aspect, to solve the above-mentioned technical problems, embodiments of this disclosure provide a display device, comprising:

[0007] The device comprises a display panel, a power management integrated circuit and a source drive circuit, and a common voltage module located outside the display panel and the power management integrated circuit; the source drive circuit is electrically connected to the display panel and the power management integrated circuit respectively; the common voltage module is used to provide a common voltage signal to the common electrode of the display panel, and the common voltage signal is at the same potential as the housing of the display device.

[0008] The power management integrated circuit is used to provide a positive voltage source and a negative voltage source to the source driving circuit; the source driving circuit is used to generate analog data signals of positive or negative polarity for the display panel, wherein the power source used for the positive analog data signal is the positive voltage source, and the power source used for the negative analog data signal is the negative voltage source.

[0009] One possible implementation, the source drive circuit includes:

[0010] Multiple gamma voltage generation circuits correspond to multiple gamma voltages; the gamma voltage generation circuits are used to buffer the corresponding original gamma voltages to obtain the corresponding gamma voltages, and the gamma voltages are used to generate the analog data signals required by the display panel; the reference voltage of the gamma voltage generation circuits includes the positive voltage source and the negative voltage source.

[0011] One possible implementation of the gamma voltage generation circuit includes:

[0012] A first operational amplifier, wherein the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier serves as the output terminal of the gamma voltage generation circuit; the two power supply terminals of the first operational amplifier are respectively connected to the positive voltage source and the negative voltage source.

[0013] The protection circuit has its input terminal serving as the input terminal of the gamma voltage generation circuit, and its output terminal connected to the non-inverting input terminal of the first operational amplifier. The two reference voltages of the protection circuit are the positive voltage source and the negative voltage source, respectively. The protection circuit is used to prevent static electricity and leakage current from the first operational amplifier.

[0014] One possible implementation of the protection circuit includes:

[0015] The second operational amplifier has a non-inverting input terminal for receiving the original gamma voltage, and its output terminal is connected to the inverting input terminal of the second operational amplifier and the non-inverting input terminal of the first operational amplifier. The second operational amplifier is used to prevent leakage at the non-inverting input terminal of the first operational amplifier.

[0016] The first diode is electrically connected between the inverting input terminal of the second operational amplifier and the positive voltage source. The first diode is used to guide the leakage current generated when the original gamma voltage is greater than 0 to the positive voltage source.

[0017] The second diode is connected between the inverting input of the second operational amplifier and the negative voltage source. The second diode is used to guide the leakage current generated when the original gamma voltage is less than 0 to the negative voltage source.

[0018] In one possible implementation, the protection circuit further includes:

[0019] A third diode and a fourth diode are connected in parallel, with the positive terminal of the third diode connected to the negative terminal of the fourth diode and the negative terminal of the first diode, and the negative terminal of the third diode connected to the positive terminal of the fourth diode and the non-inverting input terminal of the second operational amplifier.

[0020] The third diode is used to prevent positive electrostatic discharge from damaging the non-inverting input terminal of the second operational amplifier;

[0021] The fourth diode is used to prevent negative electrostatic discharge from damaging the non-inverting input of the second operational amplifier.

[0022] In one possible implementation, the protection circuit further includes:

[0023] The first resistor is connected between the inverting input terminal of the second operational amplifier and the negative terminal of the first diode;

[0024] Or / and a second resistor, connected between the input terminal of the gamma voltage generation circuit and the non-inverting input terminal of the second operational amplifier; the second resistor is configured to limit the current at the non-inverting input terminal of the second operational amplifier.

[0025] In one possible implementation, the common voltage module is grounded, and the housing is grounded.

[0026] In one possible implementation, the source drive circuit includes the common voltage generation module.

[0027] One possible implementation, a power management integrated circuit, includes:

[0028] A first power generation circuit is used to generate the positive voltage source;

[0029] The second power generation circuit is used to generate the negative voltage source.

[0030] One possible implementation of the display panel includes:

[0031] Array substrate and opposing substrate;

[0032] The array substrate includes scan lines and data lines, the scan lines and data lines intersect to define a pixel region, and the pixel region includes a pixel electrode;

[0033] The opposing substrate includes the common electrode, which is electrically connected to the common voltage module.

[0034] One possible implementation also includes:

[0035] The timing control circuit is electrically connected to the display panel and the source drive circuit.

[0036] The timing control circuit generates a control signal based on the input synchronization signal and provides the control signal to the display panel to control the source drive circuit to generate a corresponding analog data signal based on the digital data signal provided by the timing control circuit and load it onto the corresponding data line. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a display product;

[0038] Figure 2 A schematic diagram illustrating corrosion of a product due to moisture intrusion;

[0039] Figure 3 This is a schematic diagram of the structure of a display device provided in an embodiment of the present disclosure;

[0040] Figure 4 This is a schematic diagram of another display device provided in an embodiment of the present disclosure;

[0041] Figure 5 This is a schematic diagram of the structure of a voltage management integrated circuit provided in an embodiment of the present disclosure;

[0042] Figure 6 This is a schematic diagram of another display device provided in an embodiment of the present disclosure;

[0043] Figure 7 This is a schematic diagram of a gamma generation circuit with a positive voltage source as the reference voltage in related technologies.

[0044] Figure 8 This is a schematic diagram of a gamma generation circuit with a negative reference voltage source in related technologies.

[0045] Figure 9 This is a schematic diagram of another display device provided in an embodiment of the present disclosure;

[0046] Figure 10 This is a schematic diagram of the structure of a gamma generation circuit provided in an embodiment of the present disclosure;

[0047] Figure 11 A schematic diagram of another protection circuit provided in an embodiment of this disclosure;

[0048] Figure 12A schematic diagram of another protection circuit provided in an embodiment of this disclosure;

[0049] Figures 13-15 A schematic diagram of another protection circuit provided in an embodiment of this disclosure.

[0050] Figure label:

[0051] Liquid crystal display panel 100, source drive circuit 200, PMIC 300, TCON 400, housing 500, backlight 600, array substrate 100a, color filter substrate 100b, sealing glue 700, UV glue 800, front frame 500a, bottom frame 500b.

[0052] Display panel 1, power management integrated circuit 2, source drive circuit 3, common voltage module VCOM, gamma voltage generation circuit 31, first power generation circuit 21, second power generation circuit 22, main control circuit 23, first buck circuit 24, boost circuit 25, second buck circuit 26, positive voltage source PAVDD, negative voltage source NAVDD, first operational amplifier OP1, protection circuit DS, first diode D1, second diode D2, second operational amplifier OP2, third diode D3, fourth diode D4, first resistor R1, second resistor R2, array substrate 11, counter substrate 12, common electrode 121, timing control circuit 4. Detailed Implementation

[0053] This disclosure provides a display device to solve the problem that display products are prone to corrosion of the common electrode due to moisture intrusion.

[0054] To make the above-described objects, features, and advantages of this disclosure more apparent and understandable, the disclosure will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction as described in this disclosure are illustrative of the accompanying drawings, but changes may be made as needed, and all such changes are included within the scope of protection of this disclosure. The accompanying drawings of this disclosure are for illustrative purposes only and do not represent actual scale.

[0055] It should be noted that specific details are set forth in the following description to provide a full understanding of this disclosure. However, this disclosure can be implemented in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this disclosure. Therefore, this disclosure is not limited to the specific embodiments disclosed below. The following descriptions are preferred embodiments for carrying out this disclosure; however, these descriptions are for the purpose of illustrating the general principles of this disclosure and are not intended to limit the scope of this disclosure. The scope of protection of this disclosure shall be determined by the appended claims.

[0056] Please see Figure 1 This is a schematic diagram of the structure of a display product. Display products typically include a liquid crystal display panel 100, a source drive circuit 200, a PMIC 300, and a TCON 400.

[0057] The liquid crystal display panel 100 includes an array substrate 100a, a color filter substrate 100b, and liquid crystal. Data lines and gate lines are formed on the array substrate 100a. Thin film transistors (TFTs) disposed at the intersections of the data lines and gate lines are used to transmit data signals to the pixel electrodes of the array substrate 100a. The TCON 400 is used to generate control signals (such as STV / CLK / VDD) for controlling the source drive circuit 200 according to the input synchronization signal. The source drive circuit 200 is used to generate data signals required to drive the liquid crystal display panel 100 according to the data signals required by the source drive circuit 200 generated by the TCON 400, and input the data signals to the pixel electrodes of the liquid crystal display panel 100. The PMIC 300 provides the voltages required by each module. For example, the PMIC 300 provides the VCOM voltage for the liquid crystal TV panel and provides a full positive voltage (AVDD) or a full half positive voltage (HAVDD) for the source drive circuit 200.

[0058] Please see Figure 2 This diagram illustrates corrosion caused by moisture intrusion into the display product. The large-size display product includes a housing 500 (comprising a front frame 500a and a bottom frame 500b), a backlight 600, and opposing array substrates 100a and 100b. Sealing adhesive 700 is applied around the display area of ​​array substrate 100a, and UV adhesive 800 is applied to the outer edges of array substrate 100a and 100b. Because the common electrode of the large-size display product is located on the 100b side, and the source drive circuit 200 adopts a full half-voltage (HAVDD) architecture, the VCOM voltage is typically set at around 7-8V.

[0059] When conducting reliability high and low temperature tests or other tests that generate moisture, moisture may enter the gaps between the color filter substrate 100b and the array substrate 100a at the corners of the display panel where there is no UV adhesive 800 protection. The moisture comes into direct contact with the common electrode. When power is applied, a connection circuit is formed between the common electrode (the voltage of the common motor is Vcom ≒ 7V) and the housing 500 (usually grounded, which is 0V) through the moisture, causing electrochemical corrosion of the common electrode, which in turn leads to display abnormalities in the display product.

[0060] To address the aforementioned problems, this disclosure provides a display device, which will be described in detail below with reference to the accompanying drawings.

[0061] Please see Figure 3 This is a schematic diagram of a display device provided in an embodiment of the present disclosure. The display device includes:

[0062] Display panel 1, power management integrated circuit 2 and source drive circuit 3, common voltage module VCOM located outside display panel 1 and power management integrated circuit 2; source drive circuit 3 is electrically connected to display panel 1 and power management integrated circuit 2 respectively; common voltage module VCOM is used to provide common voltage signal to common electrode 121 of display panel 1, and common voltage signal is at the same potential as housing 500 (not shown) of display device.

[0063] The power management integrated circuit 2 is used to provide a positive voltage source PAVDD and a negative voltage source NAVDD to the source drive circuit 3; the source drive circuit 3 is used to generate analog data signals of positive or negative polarity for the display panel 1. The power supply used for the positive analog data signal is the positive voltage source PAVDD, and the power supply used for the negative analog data signal is the negative voltage source NAVDD.

[0064] The absolute values ​​of the positive voltage source PAVDD and the negative voltage source NAVDD are the same.

[0065] Because a common voltage module VCOM is installed in the display device, the common voltage signal provided by the common electrode 121 is at the same potential as the casing 500 of the display device. Even if moisture enters the display panel 1, no electric field will be formed between the common electrode 121 and the display panel 1 because they are at the same potential. Therefore, electrochemical corrosion will not occur on the common electrode 121. Furthermore, since the common voltage module VCOM providing the common voltage to the common electrode 121 is located outside the power management integrated circuit 2, there is no need to install a common voltage module VCOM inside the power management integrated circuit 2 as in existing technologies, thus effectively reducing the cost of the power management integrated circuit 2. Simultaneously, since the power management integrated circuit 2 provides a positive voltage source PAVDD and a negative voltage source NAVDD to the source drive circuit 3, the driving voltage inside the source drive circuit 3 can adopt a positive and negative voltage architecture. This facilitates the adjustment of flicker through the gamma circuit inside the source drive circuit 3, maintaining a better display effect.

[0066] In some embodiments, the common voltage module VCOM is grounded, and the housing 500 of the display device is also grounded. This allows the common electrode 121 and the housing 500 to have the same potential without the need for additional circuitry.

[0067] Please see Figure 4 This is a schematic diagram of another display device provided in an embodiment of the present disclosure. The display panel 1 in the display device includes:

[0068] Array substrate 11 and opposing substrate 12;

[0069] The array substrate 11 includes scan lines (not shown) and data lines (not shown), the scan lines and data lines intersecting to define a pixel region, the pixel region including a pixel electrode ( Figure 4 (Not shown);

[0070] The opposing substrate 12 includes a common electrode 121, and the common electrode 121 is connected to a common voltage module VCOM ( Figure 14 Electrical connection (not shown).

[0071] like Figure 4 As shown, since the common electrode 121 is electrically connected to the common voltage module VCOM, and the common voltage module VCOM is at the same potential as the housing 500 of the display device (e.g., both are 0V), no electric field is generated between the housing 500 and the common electrode 121. During reliability high and low temperature tests or other tests that generate water vapor, even if water vapor enters the display panel 1, it will not form a connection circuit between the housing 500 and the common electrode 121 through the water vapor, thus preventing electrochemical corrosion of the common electrode 121.

[0072] Please see Figure 5 This is a schematic diagram of a voltage management integrated circuit provided in an embodiment of the present disclosure. The power management integrated circuit 2 includes:

[0073] The first power generation circuit 21 is used to generate a positive voltage source PAVDD;

[0074] The second power generation circuit 22 is used to generate a negative voltage source NAVDD.

[0075] like Figure 5 As shown, the power management integrated circuit 2 also includes:

[0076] The main control circuit 23 is used to control the power management integrated circuit 2 according to the external signal received from VIN;

[0077] The first step-down circuit 24 is used to generate the core voltage required by the source drive circuit 3, which is usually 1.1V, and is provided to the source drive circuit 3 through VIO;

[0078] The boost circuit 25 is used to generate a high-level signal to turn on the pixels in the display panel 1, which is provided by VGH;

[0079] The second step-down circuit 26 is used to generate a low-level signal to turn off the pixels in the display panel 1, provided via VGL.

[0080] Because the power management integrated circuit 2 in the embodiments provided in this disclosure is equipped with a first power generation circuit 21 that provides a positive voltage source PAVDD and a second power generation circuit 22 that provides a negative voltage source NAVDD, the source drive circuit 3 can obtain the positive voltage source PAVDD and the negative voltage source NAVDD from the power management integrated circuit 2, thereby adopting a positive and negative voltage architecture and adjusting the gamma voltage to regulate the flickering phenomenon. At the same time, since the power management integrated circuit 2 no longer needs to be equipped with a voltage generation circuit that provides a common voltage signal, the cost of the power management integrated circuit 2 can be effectively saved.

[0081] Please see Figure 6 This is a schematic diagram of another display device provided in an embodiment of the present disclosure.

[0082] like Figure 6 As shown, the source drive circuit 3 includes a common voltage generation module. In other embodiments, the common voltage generation module may also be located in other drive circuits outside the display panel 1, such as in the gate drive circuit or in the timing control circuit 4; there are no specific limitations.

[0083] Please continue reading Figure 6 The source drive circuit 3 also includes:

[0084] Multiple gamma voltage generation circuits 31 correspond to multiple gamma voltages; the gamma voltage generation circuits 31 are used to buffer the corresponding original gamma voltages to obtain the corresponding gamma voltages, and the gamma voltages are used to generate the analog data signals required by the display panel 1; the driving voltages of the gamma voltage generation circuits 31 include a positive voltage source PAVDD and a negative voltage source NAVDD.

[0085] For example, display panel 1 includes 18 gamma voltages (denoted as GMA1 to GMA18), each gamma voltage corresponds to a gamma voltage generation circuit 31. The aforementioned gamma generation circuit can convert the digital data signal sent by the timing control board into an analog data signal that can be recognized by display panel 1.

[0086] In related technologies, the reference voltage for GMA1 to 9 is a positive voltage source PAVDD, and the reference voltage for GMA10 to 18 is a negative voltage source NAVDD, such as... Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of a gamma generation circuit with a positive voltage source as the reference voltage in related technologies. Figure 8 This is a schematic diagram of a gamma generation circuit with a negative reference voltage source, as described in related technologies. From... Figure 7 and Figure 8 It is known that gamma generation circuits in related technologies all include operational amplifier circuits (OP) and two diodes (D1', D2'), the difference being that their reference voltages are different. This circuit structure makes it impossible for any gamma generation circuit to cross 0V. For example, the gamma generation circuit corresponding to GMA10 cannot adjust from a negative voltage to a positive voltage by crossing 0V, thus making it impossible to adjust the flickering phenomenon by gamma adjustment.

[0087] Taking the adjustment of GMA10 as an example, when adjusting the input voltage Vin' corresponding to GMA10 upon power-up, diodes D1' and D2' are connected in series, with their ends connected to GND (i.e., 0V) and NAVDD respectively. The non-inverting input terminal of operational amplifier OP is connected to Vin' after passing through the anti-static barrier of diodes D1' and D2'. The power supply of operational amplifier OP is connected to GND and NAVDD respectively. When the input voltage Vin' corresponding to GMA10 is negative, the circuit supplies power normally; however, when the input voltage Vin' corresponding to GMA10 is positive, this voltage will leak through diode D1', which will cause display defects and damage to diode D1'. This limits GMA9 to > 0V and GMA10 to < 0V, which makes it inconvenient to adjust flickering through gamma voltage adjustment. Therefore, the gamma generation circuit in the existing technology cannot adjust flickering through gamma adjustment.

[0088] In this disclosure, the positive voltage source PAVDD and the negative voltage source NAVDD are used as reference voltages for the gamma generation circuit, so that the gamma voltage can be freely adjusted within the voltage range between the positive voltage source PAVDD and the negative voltage source NAVDD, thereby adjusting the flickering phenomenon by adjusting the gamma voltage.

[0089] Please see Figure 9 This is a schematic diagram of another display device provided in an embodiment of the present disclosure.

[0090] The display device also includes:

[0091] The timing control circuit 4 is electrically connected to the display panel 1 and the source drive circuit 3;

[0092] The timing control circuit 4 is used to generate a control signal based on the input synchronization signal and provide the control signal to the display panel 1 to control the source drive circuit 3 to generate a corresponding analog data signal based on the digital data signal provided by the timing control circuit 4 and load it onto the corresponding data line.

[0093] Please see Figure 10 This is a schematic diagram of a gamma generation circuit provided in an embodiment of the present disclosure.

[0094] Gamma voltage generation circuit 31 includes:

[0095] The first operational amplifier OP1 has its inverting input terminal (-) connected to its output terminal, and its output terminal serves as the output terminal Vout of the gamma voltage generation circuit 31. The two power supply terminals of the first operational amplifier OP1 are connected to the positive voltage source PAVDD and the negative voltage source NAVDD, respectively.

[0096] The protection circuit DS has its input terminal serving as the input terminal Vin of the gamma voltage generation circuit 31. The output terminal of the protection circuit DS is connected to the non-inverting input terminal of the first operational amplifier OP1. The two reference voltages of the protection circuit DS are the positive voltage source PAVDD and the negative voltage source NAVDD, respectively. The protection circuit DS is used to prevent static electricity and leakage of the first operational amplifier OP1.

[0097] The protection circuit DS can be as follows: Figure 10 The diagram shown is composed of a first diode D1 and a second diode D2. One end of the first diode D1 and the second diode D2 are connected to the non-inverting input terminal of the first operational amplifier OP1, and the other end are connected to the positive voltage source PAVDD and the negative voltage source NAVDD, respectively.

[0098] Taking the adjustment of GMA10 as an example, when adjusting the voltage received at the input terminal Vin of GMA10 after power-on, the first diode D1 and the second diode D2 are in series, with both ends connected to PAVDD and NAVDD respectively. The non-inverting input terminal of the first operational amplifier OP1 is connected to the voltage after anti-static protection through the first diode D1 and the second diode D2. The power supply of the first operational amplifier OP1 is connected to PAVDD and NAVDD respectively. When the voltage received at the corresponding input terminal of GMA10 is a negative voltage, the circuit is normally powered. When the voltage received at the corresponding input terminal Vin of GMA10 is a positive voltage, if Vin < PAVDD, the first diode D1 is cut off and no leakage current will be generated. If Vin > PAVDD, it means that Vin is static electricity, and the first diode D1 conducts to discharge the static electricity, playing a role in anti-static protection. Therefore, when the voltage received at the corresponding input terminal of GMA10 is a positive voltage, the circuit can still work normally. This enables the gamma voltage generation circuit 31 to work normally regardless of whether the original gamma voltage received at the input terminal Vin corresponding to GMA10 is positive or negative, so that the flicker phenomenon can be adjusted by adjusting the original gamma voltage.

[0099] Please refer to Figure 11 This is the schematic diagram of another protection circuit provided by the embodiments of the present disclosure. The protection circuit DS includes:

[0100] A second operational amplifier OP2, the non-inverting input terminal of the second operational amplifier OP2 is used to receive the original gamma voltage. The output terminal of the second operational amplifier OP2 is connected to the inverting input terminal of the second operational amplifier OP2 and the non-inverting input terminal of the first operational amplifier OP1. The second operational amplifier OP2 is used to prevent the non-inverting input terminal of the first operational amplifier OP1 from leaking electricity. The two power supply terminals of the second operational amplifier OP2 are respectively connected to the positive voltage source PAVDD and the negative voltage source NAVDD;

[0101] A first diode D1, electrically connected between the inverting input terminal of the second operational amplifier OP2 and the positive voltage source PAVDD. The first diode D1 is used to divert the leakage current generated when the original gamma voltage is greater than 0 to the positive voltage source PAVDD. The positive electrode of the first diode D1 is connected to the positive voltage source PAVDD, and the negative electrode of the first diode D1 is connected to the inverting input terminal of the second operational amplifier OP2.

[0102] A second diode D2, connected between the inverting input terminal of the second operational amplifier OP2 and the negative voltage source NAVDD. The second diode D2 is used to divert the leakage current generated when the original gamma voltage is less than 0 to the negative voltage source NAVDD. The positive electrode of the second diode D2 is connected to the inverting input terminal of the second operational amplifier OP2, and the negative electrode of the second diode D2 is connected to the negative voltage source NAVDD.

[0103] The second operational amplifier OP2 generates an anti-leakage original gamma voltage based on the original gamma voltage, and then sends it to the first operational amplifier OP1 for buffering into a gamma voltage, so as to convert the received digital data signal into the analog data signal required by the display panel 1.

[0104] Please refer to Figure 12 FIG. 2 is a schematic diagram of another protection circuit provided by an embodiment of the present disclosure.

[0105] The protection circuit DS further includes:

[0106] A third diode D3 and a fourth diode D4 connected in parallel. The positive electrode of the third diode D3 is between the negative electrode of the fourth diode D4 and the negative electrode of the first diode D1, and the negative electrode of the third diode D3 is connected to the positive electrode of the fourth diode D4 and the non-inverting input terminal of the second operational amplifier OP2;

[0107] The third diode D3 is used to prevent positive-polarity static electricity from damaging the non-inverting input terminal of the second operational amplifier OP2;

[0108] The fourth diode D4 is used to prevent negative-polarity static electricity from damaging the non-inverting input terminal of the second operational amplifier OP2.

[0109] As Figure 12 shown, if the input terminal Vin of the gamma voltage generation circuit 31 receives positive-polarity static electricity, Vin > PAVDD, the first diode D1 and the third diode D3 are turned on, and the positive-polarity static electricity is discharged through the path formed by the third diode D3 and the first diode D1; if the input terminal Vin of the gamma voltage generation circuit 31 receives negative-polarity static electricity, Vin < NAVDD, the second diode D2 and the fourth diode D4 are turned on, and the negative-polarity static electricity is discharged through the path formed by the fourth diode D4 and the second diode D2, thereby preventing static electricity from damaging the second operational amplifier OP2. If the input terminal Vin of the gamma voltage generation circuit 31 receives positive and negative original gamma voltages, then 0 < Vin < PAVDD, the third diode D3 is turned on, and the first diode D1 and the second diode D2 are turned off, and no leakage current will occur; if the input terminal Vin of the gamma voltage generation circuit 31 receives negative-polarity original gamma voltage, then NAVDD < Vin < 0, the fourth diode D4 is turned on, and the first diode D1 and the second diode D2 are turned off, and no leakage current will occur either, so leakage current can be prevented from generating.

[0110] In the embodiments provided in this disclosure, by setting a third diode D3 and a fourth diode D4 in parallel at the non-inverting input terminal of the second operational amplifier OP2, and connecting the positive terminal of the third diode D3 with the negative terminal of the fourth diode D4 and the negative terminal of the first diode D1, and connecting the negative terminal of the third diode D3 with the positive terminal of the fourth diode D4 and the non-inverting input terminal of the second operational amplifier OP2, electrostatic damage to the non-inverting input terminal of the second operational amplifier OP2 can be prevented, and leakage current can be effectively prevented even with the original gamma voltage of positive or negative polarity.

[0111] Please see Figures 13-15 A schematic diagram of another protection circuit provided in an embodiment of this disclosure.

[0112] The protection circuit DS also includes:

[0113] The first resistor R1 is connected between the inverting input terminal of the second operational amplifier OP2 and the negative terminal of the first diode D1;

[0114] Or / and a second resistor R2, connected between the input terminal Vin of the gamma voltage generation circuit 31 and the non-inverting input terminal of the second operational amplifier OP2; the second resistor R2 is configured to limit the leakage current at the non-inverting input terminal of the second operational amplifier OP2.

[0115] like Figure 13 As shown, a first resistor R1 can be placed between the inverting input terminal of the second operational amplifier OP2 and the cathode of the first diode D1 to limit the current flowing into the positive voltage source PAVDD and the negative voltage source NAVDD, thereby protecting the second operational amplifier OP2 and the first operational amplifier OP1; or as shown in the diagram... Figure 14 As shown, a second resistor R2 is placed between the non-inverting input terminal and the input terminal Vin of the second operational amplifier OP2 to limit the current flowing into the non-inverting input terminal of the second operational amplifier OP2, thereby protecting the second operational amplifier OP2. The aforementioned first resistor R1 and second resistor R2 can be configured as follows: Figure 15 As shown, it is also set in the anti-static protection circuit DS, thereby strengthening the protection of the first operational amplifier OP1 and the second operational amplifier OP2.

[0116] The display device can be a liquid crystal display, liquid crystal screen, liquid crystal television, or other display devices, or a mobile device such as a mobile phone, tablet computer, or laptop.

[0117] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0118] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A display device, comprising: Display panel, power management integrated circuit and source drive circuit, and common voltage module located outside the display panel and the power management integrated circuit; The source drive circuit is electrically connected to the display panel and the power management integrated circuit respectively; the common voltage module is used to provide a common voltage signal to the common electrode of the display panel, and the common voltage signal is at the same potential as the housing of the display device; The power management integrated circuit is used to provide a positive voltage source and a negative voltage source to the source driving circuit; the source driving circuit is used to generate analog data signals of positive or negative polarity for the display panel, wherein the power source used for the positive analog data signal is the positive voltage source, and the power source used for the negative analog data signal is the negative voltage source; The source drive circuit includes: Multiple gamma voltage generation circuits correspond to multiple gamma voltages; the gamma voltage generation circuit is used to buffer the corresponding original gamma voltage to obtain the corresponding gamma voltage, and the gamma voltage is used to generate the analog data signal required by the display panel; the reference voltage of the gamma voltage generation circuit includes the positive voltage source and the negative voltage source; The gamma voltage generation circuit includes: A first operational amplifier, wherein the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier serves as the output terminal of the gamma voltage generation circuit; the two power supply terminals of the first operational amplifier are respectively connected to the positive voltage source and the negative voltage source. The protection circuit has its input terminal serving as the input terminal of the gamma voltage generation circuit, and its output terminal connected to the non-inverting input terminal of the first operational amplifier. The two reference voltages of the protection circuit are the positive voltage source and the negative voltage source, respectively. The protection circuit is used to prevent static electricity and leakage current from the first operational amplifier.

2. The display device as claimed in claim 1, wherein the protection circuit comprises: The second operational amplifier has a non-inverting input terminal for receiving the original gamma voltage, and its output terminal is connected to the inverting input terminal of the second operational amplifier and the non-inverting input terminal of the first operational amplifier. The second operational amplifier is used to prevent leakage at the non-inverting input terminal of the first operational amplifier. The first diode is electrically connected between the inverting input terminal of the second operational amplifier and the positive voltage source. The first diode is used to guide the leakage current generated when the original gamma voltage is greater than 0 to the positive voltage source. The second diode is connected between the inverting input of the second operational amplifier and the negative voltage source. The second diode is used to guide the leakage current generated when the original gamma voltage is less than 0 to the negative voltage source.

3. The display device as described in claim 2, wherein the protection circuit further comprises: A third diode and a fourth diode are connected in parallel, with the positive terminal of the third diode connected to the negative terminal of the fourth diode and the negative terminal of the first diode, and the negative terminal of the third diode connected to the positive terminal of the fourth diode and the non-inverting input terminal of the second operational amplifier. The third diode is used to prevent positive electrostatic discharge from damaging the non-inverting input terminal of the second operational amplifier; The fourth diode is used to prevent negative electrostatic discharge from damaging the non-inverting input of the second operational amplifier.

4. The display device as claimed in claim 3, wherein the protection circuit further comprises: The first resistor is connected between the inverting input terminal of the second operational amplifier and the negative terminal of the first diode; Or / and a second resistor, connected between the input terminal of the gamma voltage generation circuit and the non-inverting input terminal of the second operational amplifier; the second resistor is configured to limit the current at the non-inverting input terminal of the second operational amplifier.

5. The display device according to any one of claims 1-4, wherein the common voltage module is grounded and the housing is grounded.

6. The display device as claimed in claim 5, wherein the source drive circuit includes the common voltage module.

7. The display device of claim 5, wherein the power management integrated circuit comprises: A first power generation circuit is used to generate the positive voltage source; The second power generation circuit is used to generate the negative voltage source.

8. The display device as claimed in claim 5, wherein the display panel comprises: Array substrate and opposing substrate; The array substrate includes scan lines and data lines, the scan lines and data lines intersect to define a pixel region, and the pixel region includes a pixel electrode; The opposing substrate includes the common electrode, which is electrically connected to the common voltage module.

9. The display device as claimed in claim 8, further comprising: The timing control circuit is electrically connected to the display panel and the source drive circuit. The timing control circuit generates a control signal based on the input synchronization signal and provides the control signal to the display panel to control the source drive circuit to generate a corresponding analog data signal based on the digital data signal provided by the timing control circuit and load it onto the corresponding data line.

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