Wide and narrow viewing angle switching circuit and display device

Abstract

The utility model discloses a wide and narrow viewing angle switching circuit and a display device, and the circuit comprises a power module which generates a first voltage, a positive and negative second voltage, and a positive and negative third voltage; the square wave module receives the positive second voltage to generate a first square wave voltage; the switch module receives the positive and negative second voltages, the positive and negative third voltages and a visual angle control signal to output the positive and negative second voltages or the positive and negative third voltages; the operational amplifier module receives and compares the first voltage with the first square wave voltage to generate a second square wave voltage. According to the wide and narrow view angle switching circuit and the display device, the square wave module provides the square wave signal to the operational amplification module, and the HVA signal control switch module provides the high voltage or the low voltage to the operational amplification module, so that the operational amplification module outputs the second square wave voltage required by the wide and narrow view angle signal; elements such as a micro-control unit, an analog-to-digital converter and a crystal oscillator are saved, the cost is reduced, and meanwhile, the design size of the PCBA can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of display, in particular to a wide and narrow viewing angle switching circuit and a display device. Background Art

[0002] Liquid crystal display devices (LCDs) have many advantages such as being thin, light, energy-saving, and radiation-free, so they have gradually replaced traditional cathode ray tube (CRT) display devices. Currently, liquid crystal display devices are widely used in electronic devices such as high-definition digital TVs, desktop computers, personal digital assistants (PDAs), laptop computers, mobile phones, digital cameras, etc.

[0003] Existing liquid crystal display devices need to apply corresponding common voltages to the pixel electrodes and common electrodes inside to generate corresponding electric fields to control the deflection of liquid crystal molecules to adjust the transmittance of the liquid crystal layer, thereby realizing image display. Moreover, due to the more stringent requirements of people in today's society for the application scenarios of liquid crystal display devices, existing liquid crystal display devices are gradually developing towards the direction of viewing angle switching, such as wide viewing angle mode and narrow viewing angle mode.

[0004] In the existing wide and narrow viewing angle display screen design, the waveform of the viewing angle voltage EQ is generated by a micro control unit MCU and / or a digital-to-analog converter DAC, and then enters the connector Connector after passing through an operational amplifier OP. And it also takes a lot of time to debug the source code code of the micro control unit MCU. As Figure 1 shown, a wide and narrow viewing angle circuit requires a micro control unit MCU, a crystal oscillator, a digital-to-analog converter DAC, a switch SW, and several transistor MOSs and resistors. At the same time, it takes a lot of time to debug the source code code of the micro control unit MCU, which will result in more chip IC components in the wide and narrow viewing angle circuit, a long material preparation cycle, a high cost, and a high raw material cost for the printed circuit board assembly (PCBA) with a wide and narrow viewing angle circuit, wasting manpower, material resources, and time. Summary of the Utility Model

[0005] In view of the above problems, the purpose of the present utility model is to provide a wide and narrow viewing angle switching circuit and a display device. The square wave module provides a square wave signal to the operational amplification module, and the HVA signal controls the switch module to provide a high voltage or a low voltage to the operational amplification module, so that the operational amplification module outputs the level required for the wide and narrow viewing angle signal, saving components such as a micro control unit, an analog-to-digital converter, and a crystal oscillator, reducing the cost, and at the same time, the design size of the PCBA can be reduced.

[0006] According to one aspect of the present utility model, a wide and narrow viewing angle switching circuit is provided, including: a power supply module that generates a first voltage, positive and negative second voltages, and positive and negative third voltages; a square wave module connected to the power supply module, receiving the positive second voltage to generate a first square wave voltage; a switching module connected to the power supply module, receiving the positive and negative second voltages, the positive and negative third voltages, and a viewing angle control signal to output the positive and negative second voltages or the positive and negative third voltages; an operational amplifier module connected to the power supply module, the square wave module, and the switching module, receiving and comparing the first voltage with the first square wave voltage to generate a second square wave voltage, wherein the high level of the second square wave voltage is the positive second voltage and the low level is the negative second voltage; or the high level of the second square wave voltage is the positive third voltage and the low level is the negative third voltage.

[0007] Optionally, it further includes: an HVA control module that generates a viewing angle control signal, and the viewing angle control signal includes a wide viewing angle control signal and a narrow viewing angle control signal.

[0008] Optionally, the square wave module includes: a first resistor, the first end of which is connected to the power supply module to receive the positive second voltage; a third transistor, the first end of the third transistor is connected to the second end of the first resistor, the second end is connected to the ground terminal, and the control terminal receives a third square wave voltage, and the third square wave voltage controls the on and off of the third transistor.

[0009] Optionally, the switching module includes a first channel and a second channel, the first channel outputs the positive second voltage or the positive third voltage, and the second channel outputs the negative second voltage or the negative third voltage.

[0010] Optionally, the first channel includes: a first single-pole double-throw switch, the first input terminal of the first single-pole double-throw switch is connected to the power supply module to receive the positive third voltage, the second input terminal is connected to the power supply module to receive the positive second voltage; a first operational amplifier, the input terminal is connected to the HVA control module, and the output terminal is connected to the first single-pole double-throw switch, and the viewing angle control signal controls the output terminal of the first single-pole double-throw switch to be connected to the first input terminal or the second input terminal.

[0011] Optionally, the second channel includes: a second single-pole double-throw switch, the first input terminal of the second single-pole double-throw switch is connected to the power supply module to receive the negative third voltage, the second input terminal is connected to the power supply module to receive the negative second voltage; a second operational amplifier, the input terminal is connected to the HVA control module, and the output terminal is connected to the second single-pole double-throw switch, and the viewing angle control signal controls the output terminal of the second single-pole double-throw switch to be connected to the first input terminal or the second input terminal.

[0012] Optionally, the viewing angle control signal controls the connection of the output terminal of the first single-pole double-throw switch to the first input terminal and the connection of the output terminal of the second single-pole double-throw switch to the first input terminal; or the viewing angle control signal controls the connection of the output terminal of the first single-pole double-throw switch to the second input terminal and the connection of the output terminal of the second single-pole double-throw switch to the second input terminal.

[0013] Optionally, the operational amplifier module includes: a second resistor, the first end of which is connected to the power supply module to receive a first voltage; a third operational amplifier, the first input terminal of the third operational amplifier is connected to the output terminal of the second channel, the second input terminal is connected to the second end of the second resistor, the third input terminal is connected to the output terminal of the square wave module, and the fourth input terminal is connected to the output terminal of the second channel. Wherein, the third operational amplifier compares the voltages of the second input terminal and the third input terminal. When the voltage of the second input terminal is greater than the voltage of the third input terminal, the third operational amplifier outputs the voltage of the first input terminal; when the voltage of the second input terminal is less than the voltage of the third input terminal, the third operational amplifier outputs the voltage of the fourth input terminal.

[0014] Optionally, it further includes: a wide and narrow viewing angle module, connected to the operational amplifier module, and receiving the second square wave voltage to generate a wide viewing angle signal or a narrow viewing angle signal.

[0015] According to another aspect of the present invention, a display device is provided, including the above-mentioned wide and narrow viewing angle switching circuit.

[0016] The wide and narrow viewing angle switching circuit and the display device provided by the present invention provide a square wave signal to the operational amplifier module through the square wave module, and the HVA signal control module generates a control signal to control the voltage provided by the switch module to the operational amplifier module to be a high voltage or a low voltage, so that the operational amplifier module outputs the voltage required for the wide and narrow viewing angle signals, thereby saving components such as a micro control unit, an analog-to-digital converter, and a crystal oscillator, reducing costs, and at the same time reducing the design size of the PCBA. Description of the Drawings

[0017] Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0018] Figure 1 The structure diagram of the wide and narrow viewing angle circuit according to the prior art is shown;

[0019] Figure 2 The structure diagram of the wide and narrow viewing angle circuit according to the embodiment of the present invention is shown;

[0020] Figure 3 The structure diagram of the switch module in the wide and narrow viewing angle circuit according to the embodiment of the present invention is shown;

[0021] Figure 4 Shows an equivalent circuit diagram of a wide and narrow viewing angle circuit in a wide viewing angle mode according to an embodiment of the present invention;

[0022] Figure 5 Shows a waveform simulation diagram of an equivalent circuit diagram of a wide and narrow viewing angle circuit in a wide viewing angle mode according to an embodiment of the present invention;

[0023] Figure 6 Shows an equivalent circuit diagram of a wide and narrow viewing angle circuit in a narrow viewing angle mode according to an embodiment of the present invention;

[0024] Figure 7 Shows a waveform simulation diagram of an equivalent circuit diagram of a wide and narrow viewing angle circuit in a narrow viewing angle mode according to an embodiment of the present invention. Detailed implementation manners

[0025] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the drawings, the same elements are denoted by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0026] The following will further describe in detail the specific implementation manners of the present invention in conjunction with the accompanying drawings and embodiments.

[0027] Figure 2 Shows a structural diagram of a wide and narrow viewing angle circuit according to an embodiment of the present invention.

[0028] Reference Figure 2 , the wide and narrow viewing angle circuit 100 of the present application includes: a power supply module 110, a square wave module 120, a switch module 130, an HVA control module 140, an operational amplifier module 150, and a wide and narrow viewing angle module 160. The wide and narrow viewing angle circuit 100 is located in a display device and is used to control the display device to perform wide viewing angle or narrow viewing angle display.

[0029] Among them, the power supply module 110 is used to provide a first voltage (1.8V), positive and negative second voltages (±2.6V), and positive and negative third voltages (±5.2V). The square wave module 120 is connected to the power supply module 110, receives the positive second voltage (2.6V) provided by the power supply module 110, and generates a first square wave voltage with a low level of 0V and a high level of the positive second voltage (2.6V); the HVA control module 140 is used to generate a viewing angle control signal HVA; the switch module 130 is connected to the power supply module 110 and the HVA control module 140 to receive the positive and negative second voltages (±2.6V) and positive and negative third voltages (±5.2V) generated by the power supply module 110, and the viewing angle control signal HVA generated by the HVA control module 140, and outputs the positive and negative second voltages (±2.6V) or positive and negative third voltages (±5.2V) under the control of the viewing angle control signal HVA; the operational amplifier module 150 is connected to the power supply module 110, the square wave module 120, and the switch module 130. By comparing the magnitude relationship between the first voltage (1.8V) provided by the power supply module 110 and the first square wave voltage provided by the square wave module 120, a second square wave voltage is output according to the comparison result; the wide and narrow viewing angle module 160 is connected to the operational amplifier module 150, and is used to generate a wide viewing angle signal or a narrow viewing angle signal according to the second square wave voltage, so that the display panel performs wide viewing angle or narrow viewing angle display. In this embodiment, the viewing angle control signal HVA includes, for example, a wide viewing angle control signal WVA and a narrow viewing angle control signal NVA, and the HVA control module 140 can only generate one of the wide viewing angle control signal WVA and the narrow viewing angle control signal NVA at the same time.

[0030] In this embodiment, the square wave module 120 is, for example, a partial structure in the timing controller, and generates the first square wave voltage according to the square wave signal of the timing controller.

[0031] Among them, the structure of the switch module 130 is as Figure 3 shown. The switch module 130 includes a first channel 131 and a second channel 132. The structures of the two channels are the same, but the connected signals are different. Specifically, the first channel 131 includes a first single-pole double-throw switch SW1 and a first operational amplifier OP1; the second channel 132 includes a second single-pole double-throw switch SW2 and a second operational amplifier OP2.

[0032] In the first channel 131, the first single-pole double-throw switch SW1 includes two input terminals and one output terminal. The first input terminal NC receives the positive third voltage (5.2V) provided by the power supply module 110, and the second input terminal NO receives the positive second voltage (2.6V) provided by the power supply module 110. The viewing angle control signal HVA is connected to the first single-pole double-throw switch SW1 after passing through the first operational amplifier OP1, and is used to control whether the output terminal COM in the first single-pole double-throw switch SW1 is connected to the first input terminal NC or the second input terminal NO, so as to determine the output signal OUT1. Similarly, the second single-pole double-throw switch SW2 includes two input terminals and one output terminal. The first input terminal NC receives the negative third voltage (-5.2V) provided by the power supply module 110, and the second input terminal NO receives the negative second voltage (-2.6V) provided by the power supply module 110. The viewing angle control signal HVA is connected to the second single-pole double-throw switch SW2 after passing through the second operational amplifier OP2, and is used to control whether the output terminal COM2 in the second single-pole double-throw switch SW2 is connected to the first input terminal NC or the second input terminal NO, so as to determine the output signal OUT2.

[0033] In addition, the viewing angle control signal HVA makes the values of the voltages output by the first channel 131 and the second channel 132 of the switch module 130 the same and opposite in polarity. For example, the wide viewing angle control signal WVA in the viewing angle control signal HVA makes the output terminal COM1 of the first single-pole double-throw switch SW1 connected to the first input terminal NC, and makes the output terminal COM2 of the second single-pole double-throw switch SW2 connected to the first input terminal NC. Thus, the switch module 130 outputs positive and negative third voltages (±5.2V) under the control of the wide viewing angle control signal WVA; while the narrow viewing angle control signal NVA in the viewing angle control signal HVA makes the output terminal COM1 of the first single-pole double-throw switch SW1 connected to the second input terminal NO, and makes the output terminal COM2 of the second single-pole double-throw switch SW2 connected to the second input terminal NO. Thus, the switch module 130 outputs positive and negative second voltages (±2.6V) under the control of the narrow viewing angle control signal NVA.

[0034] Furthermore, referring to Figure 4 , the square wave module 120 includes, for example, a first resistor R1 and a third transistor T3. Specifically, the first end of the third transistor T3 is connected to the power supply module 110 via the first resistor R1, the second end is connected to the ground terminal GND, and the control end is connected to the timing controller for receiving a third square wave voltage. In Figure 4 , for example, the alternating current power supply VG1 is used to represent the third square wave voltage received from the timing controller. Among them, the first end of the third transistor T3 is, for example, the drain end, and the second end is, for example, the source end.

[0035] The operational amplifier module 150 includes a second resistor R2 and a third operational amplifier U1. Specifically, the third operational amplifier U1 includes four input terminals and one output terminal. The first input terminal is connected to the output terminal OUT2 of the second channel 132 of the switch module 130. The second input terminal is connected to the power supply module 110 via the second resistor R2. The third input terminal is connected to the output terminal of the square wave module 120. The fourth input terminal is connected to the output terminal OUT1 of the first channel 131 of the switch module 130. Among them, the first input terminal and the second input terminal of the third operational amplifier U1 are inverting input terminals, and the third input terminal and the fourth input terminal are non-inverting input terminals.

[0036] The wide and narrow viewing angle circuit 100 of the present application, as Figure 4 and Figure 5 shown, the process of an embodiment for generating a wide viewing angle signal includes: the HVA control module 140 generates a wide viewing angle control signal WVA to control the switch module 130 to output positive and negative third voltages (±5.2V); the power supply module 110 provides a positive second voltage (2.6V) to the square wave module 120. At the same time, the square wave module 120 receives a third square wave voltage of 0V - 0.9V provided by the timing controller. This third square wave voltage controls the on and off of the third transistor T3 in the square wave module 120. When the third square wave voltage is 0.9V, the third transistor T3 is turned on, and the voltage at its drain is 0V. When the third square wave voltage is 0V, the third transistor T3 is turned off, and the voltage at its drain is the voltage of the power supply module 110, which is 2.6V. Thus, by controlling the on and off of the third transistor T3, a first square wave voltage of 0V or 2.6V is generated at the drain of the third transistor T3; the second input terminal of the operational amplifier module 150 is connected to the power supply module 110 to receive a first voltage of 1.8V, and the third input terminal is connected to the drain of the third transistor T3 in the square wave module 120 to receive the first square wave voltage. The operational amplifier module 150 determines whether to output a positive third voltage (5.2V) or a negative third voltage (-5.2V) by comparing the magnitudes of the voltages received at its second input terminal and third input terminal. Specifically, when the voltage at the second input terminal of the operational amplifier module 150 is greater than the voltage at the third input terminal, the operational amplifier module 150 outputs the negative third voltage (-5.2V) at the first input terminal. Conversely, when the voltage at the second input terminal of the operational amplifier module 150 is less than the voltage at the third input terminal, the operational amplifier module 150 outputs the positive third voltage (5.2V) at the fourth input terminal.

[0037] The wide and narrow viewing angle circuit 100 of the present application, as Figure 6 and Figure 7As shown in the figure, the process of an embodiment for generating a narrow viewing angle signal includes: The HVA control module 140 generates a narrow viewing angle control signal NVA to control the switch module 130 to output positive and negative second voltages (±2.6V); The power supply module 110 supplies a positive second voltage (2.6V) to the square wave module 120. Meanwhile, the square wave module 120 receives a third square wave voltage of 0V - 0.9V provided by the timing controller. This third square wave voltage controls the conduction and cutoff of the third transistor T3 in the square wave module 120. When the third square wave voltage is 0.9V, the third transistor T3 conducts, and the voltage at its drain is 0V. When the third square wave voltage is 0V, the third transistor T3 cuts off, and the voltage at its drain is the voltage of the power supply module 110, which is 2.6V. Thus, by controlling the conduction and cutoff of the third transistor T3, a first square wave voltage of 0V or 2.6V is generated at the drain of the third transistor T3; The second input terminal of the operational amplifier module 150 is connected to the power supply module 110 to receive a first voltage of 1.8V, and the third input terminal is connected to the drain of the third transistor T3 in the square wave module 120 to receive the first square wave voltage. The operational amplifier module 150 determines whether to output a positive second voltage (2.6V) or a negative third voltage (-2.6V) by comparing the magnitudes of the voltages received at its second input terminal and third input terminal. Specifically, when the voltage at the second input terminal of the operational amplifier module 150 is greater than the voltage at the third input terminal, the operational amplifier module 150 outputs the negative third voltage (-2.6V) at the first input terminal. Conversely, when the voltage at the second input terminal of the operational amplifier module 150 is less than the voltage at the third input terminal, the operational amplifier module 150 outputs the positive third voltage (2.6V) at the fourth input terminal.

[0038] The wide and narrow viewing angle switching circuit and display device provided by the present utility model supply a square wave signal from the square wave module to the operational amplifier module. The HVA control module generates a control signal to control the voltage supplied by the switch module to the operational amplifier module to be a high voltage or a low voltage, so that the operational amplifier module outputs the voltage required for the wide and narrow viewing angle signals, thereby saving components such as a micro control unit, an analog-to-digital converter, and a crystal oscillator, reducing costs, and at the same time enabling the design size of the PCBAA to be reduced.

[0039] According to the embodiments of the present utility model as described above, these embodiments do not describe all details in detail, nor limit the utility model to only the specific embodiments described. Obviously, many modifications and variations can be made according to the above description. The purpose of selecting and specifically describing these embodiments in this specification is to better explain the principle and practical application of the present utility model, so that those skilled in the art can make good use of the present utility model and its modifications based on the present utility model. The present utility model is only limited by the claims and their full scope and equivalents.

Claims

1. A wide and narrow viewing angle switching circuit, characterized in that Comprising: A power supply module that generates a first voltage, positive and negative second voltages, and positive and negative third voltages; A square wave module connected to the power supply module, receiving the positive second voltage to generate a first square wave voltage; A switching module connected to the power supply module, receiving the positive and negative second voltages, positive and negative third voltages, and a viewing angle control signal to output the positive and negative second voltages or positive and negative third voltages; An operational amplifier module connected to the power supply module, the square wave module, and the switching module, receiving and comparing the first voltage with the first square wave voltage to generate a second square wave voltage, wherein the high level of the second square wave voltage is the positive second voltage and the low level is the negative second voltage; or the high level of the second square wave voltage is the positive third voltage and the low level is the negative third voltage.

2. The wide and narrow viewing angle switching circuit according to claim 1, wherein Further comprising: An HVA control module that generates a viewing angle control signal, the viewing angle control signal including a wide viewing angle control signal and a narrow viewing angle control signal.

3. The width-variable viewing angle switching circuit according to claim 2, wherein The square wave module includes: A first resistor, the first end of which is connected to the power supply module to receive the positive second voltage; A third transistor, the first end of the third transistor is connected to the second end of the first resistor, the second end is connected to the ground terminal, and the control terminal receives a third square wave voltage, and the third square wave voltage controls the on and off of the third transistor.

4. The wide and narrow viewing angle switching circuit according to claim 2, wherein The switching module includes a first channel and a second channel, the first channel outputs the positive second voltage or the positive third voltage, and the second channel outputs the negative second voltage or the negative third voltage.

5. The width-variable viewing angle switching circuit according to claim 4, wherein The first channel includes: A first single-pole double-throw switch, the first input terminal of the first single-pole double-throw switch is connected to the power supply module to receive the positive third voltage, and the second input terminal is connected to the power supply module to receive the positive second voltage; A first operational amplifier, the input terminal is connected to the HVA control module, and the output terminal is connected to the first single-pole double-throw switch, and the viewing angle control signal controls the output terminal of the first single-pole double-throw switch to be connected to the first input terminal or the second input terminal.

6. The wide and narrow viewing angle switching circuit according to claim 5, wherein The second channel includes: A second single-pole double-throw switch, the first input terminal of the second single-pole double-throw switch is connected to the power supply module to receive the negative third voltage, and the second input terminal is connected to the power supply module to receive the negative second voltage; A second operational amplifier, the input terminal is connected to the HVA control module, and the output terminal is connected to the second single-pole double-throw switch, and the viewing angle control signal controls the output terminal of the second single-pole double-throw switch to be connected to the first input terminal or the second input terminal.

7. The narrow-wide viewing angle switching circuit according to claim 6, wherein The viewing angle control signal controls the output terminal of the first single-pole double-throw switch to be connected to the first input terminal and the output terminal of the second single-pole double-throw switch to be connected to the first input terminal; or The viewing angle control signal controls the output terminal of the first single-pole double-throw switch to be connected to the second input terminal and the output terminal of the second single-pole double-throw switch to be connected to the second input terminal.

8. The switching circuit for wide and narrow viewing angles according to claim 7, wherein The operational amplifier module includes: A second resistor, the first end of which is connected to the power supply module to receive the first voltage; A third operational amplifier, wherein a first input terminal of the third operational amplifier is connected to an output terminal of the second channel, a second input terminal is connected to a second terminal of the second resistor, a third input terminal is connected to an output terminal of the square wave module, and a fourth input terminal is connected to the output terminal of the second channel. Wherein, the third operational amplifier compares the voltages of the second input terminal and the third input terminal. When the voltage of the second input terminal is greater than the voltage of the third input terminal, the third operational amplifier outputs the voltage of the first input terminal; when the voltage of the second input terminal is less than the voltage of the third input terminal, the third operational amplifier outputs the voltage of the fourth input terminal.

9. The switching circuit for wide and narrow viewing angles according to claim 1, wherein Further comprising: A wide and narrow viewing angle module, connected to the operational amplifier module, and receiving the second square wave voltage to generate a wide viewing angle signal or a narrow viewing angle signal.

10. A display device, characterized in that, Comprising the wide and narrow viewing angle switching circuit according to any one of claims 1-9.

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