Wide-narrow visual angle control circuit, wide-narrow visual angle control module and display device

Abstract

The utility model discloses a wide-narrow visual angle control circuit and a display device, and the wide-narrow visual angle control circuit controls a dimming signal of wide-narrow visual angle switching of a display panel, and comprises a control module which receives a positive voltage and a negative voltage to generate a wide-narrow control signal; the operational amplification module is connected with the control module and is used for receiving the positive voltage, the negative voltage and the width control signal so as to generate a width visual angle signal; and the comparison module is connected with the operational amplification module and is used for receiving the wide-narrow visual angle signal so as to generate the dimming signal, and the display panel is used for displaying a wide visual angle picture or a narrow visual angle picture after receiving the dimming signal. According to the wide and narrow visual angle control circuit and the display device, the dimming signal is generated through mutual cooperation of the power management module, the operational amplification module, the comparison module and the control module to achieve the effect of a micro-control unit, so that one micro-control unit and one digital-to-analog converter can be saved, and the cost is further saved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal display, and particularly relates to a wide and narrow viewing angle control circuit, a wide and narrow viewing angle control module and a display device. Background Art

[0002] Liquid crystal displays have a good development trend in the display technology field due to their advantages such as low power consumption, thin body, no radiation, and soft picture.

[0003] A liquid crystal display module (Liquid Crystal Display Module, LC) is a display component in a liquid crystal display, mainly composed of structures such as a display panel, a backlight source, and a printed circuit board. Among them, a circuit for controlling the operation of the display panel and the backlight source is provided on the printed circuit board. In order to enrich the functions of the liquid crystal display device, such as the anti-peeping function, a micro control unit (MCU) is usually provided on the printed circuit board, and different functions are realized by controlling the liquid crystal display module through the MCU. With the continuous development and upgrading of liquid crystal display products, the functions of the MCU have also increased, and a dedicated electrical engineer (EE) is more needed to write program codes to control the operation of the liquid crystal display device. Therefore, it is extremely urgent to improve the product competitiveness in various HVA models. Summary of the Utility Model

[0004] In view of the above problems, the purpose of the utility model is to provide a wide and narrow viewing angle control circuit, a wide and narrow viewing angle control module and a display device. The power management module, the operational amplifier module, the comparison module and the control module cooperate with each other to generate a dimming signal to achieve the function of the micro control unit, so that one micro control unit and one digital-to-analog converter can be saved, and the cost can be saved accordingly.

[0005] According to one aspect of the utility model, a wide and narrow viewing angle control circuit is provided, including: a control module, which receives a positive voltage and a negative voltage to generate a wide and narrow control signal; an operational amplifier module, connected to the control module, receiving the positive voltage, the negative voltage and the wide and narrow control signal to generate a wide and narrow viewing angle signal; a comparison module, connected to the operational amplifier module, receiving the wide and narrow viewing angle signal to generate a dimming signal, and the display panel performs wide viewing angle picture display or narrow viewing angle picture display after receiving the dimming signal.

[0006] Preferably, it further includes: a second power management module, connected to the control module and the operational amplifier module, receiving an input voltage to generate the positive voltage and the negative voltage.

[0007] Preferably, the second power management module includes: a first chip including at least three input terminals and two output terminals, wherein a first input terminal receives an input voltage, a first output terminal outputs the positive voltage, and a second output terminal outputs the negative voltage; a second resistor, wherein a second input terminal of the first chip receives an I / O power supply voltage via the second resistor; a third resistor, wherein a third input terminal of the first chip receives an I / O power supply voltage via the third resistor; a third capacitor, wherein a first end of the third capacitor is connected to the second output terminal of the first chip, and a second end is connected to a ground terminal; a fourth capacitor, wherein a first end of the fourth capacitor is connected to the first output terminal of the first chip, and a second end is connected to the ground terminal.

[0008] Preferably, the control module includes: a viewing angle unit that generates a high level or a low level; a first switch, wherein a first end of the first switch is connected to the viewing angle unit, and the first switch is turned off after receiving a low level or turned on after receiving a high level; an eighth resistor, wherein a first end of the eighth resistor is connected to a second end of the first switch; a first transistor, wherein a control end of the first transistor is connected to a second end of the eighth resistor, a first end is connected to the ground terminal, and a second end is connected to a first output terminal; a tenth resistor, wherein a first end of the tenth resistor is connected to the second end of the first transistor, and a second end is connected to the first output terminal of the second power management module; a second transistor, wherein a control end of the second transistor is connected to the second end of the eighth resistor; a third transistor, wherein a control end of the third transistor is connected to a second end of the second transistor, a first end is grounded, and a second end is connected to a second output terminal; a twelfth resistor, wherein a first end of the twelfth resistor is connected to the second end of the third transistor, and a second end is connected to the second output terminal of the second power management module.

[0009] Preferably, the operational amplifier module includes a first channel and a second channel.

[0010] Preferably, the first channel of the operational amplifier module includes: a thirteenth resistor, the first end of which is connected to the first output end of the second power management module; a fourteenth resistor, the first end of which is connected to the first output end of the control module, and the second end of which is connected to the second end of the thirteenth resistor; a first operational amplifier, including a positive input terminal, a negative input terminal and an output terminal, the positive input terminal is connected to the second end of the thirteenth resistor, the negative input terminal is connected to the output terminal, and the output terminal is connected to the first output end of the operational amplifier module; the second channel of the operational amplifier module includes: a fifteenth resistor, the first end of which is connected to the second output end of the second power management module; a sixteenth resistor, the first end of which is connected to the second output end of the control module, and the second end of which is connected to the second end of the fifteenth resistor; a second operational amplifier, including a positive input terminal, a negative input terminal and an output terminal, the positive input terminal is connected to the second end of the fifteenth resistor, the negative input terminal is connected to the output terminal, and the output terminal is connected to the second output end of the operational amplifier module.

[0011] Preferably, the comparison module further receives a reference voltage and a square wave voltage, and generates a dimming signal according to the reference voltage, the square wave voltage and the wide and narrow viewing angle signal.

[0012] Preferably, the comparison module includes: a sixth resistor and a seventh resistor connected in series, the first end of the sixth resistor is connected to the timing controller, and the second end of the seventh resistor is connected to the ground terminal; a comparator, including four input terminals and an output terminal, the first input terminal is an inverting input terminal, which is connected to the connection midpoint of the sixth resistor and the seventh resistor, the second input terminal is a non-inverting input terminal, which receives the square wave voltage, the third input terminal is a negative power supply terminal, which is connected to the second output end of the operational amplifier module, the fourth input terminal is a positive power supply terminal, which is connected to the first output end of the operational amplifier module, and the output terminal outputs a dimming signal; a seventeenth resistor, the first end of which is connected to the output terminal of the comparator, and the second end of which is connected to the ground terminal.

[0013] According to another aspect of the present invention, there is provided a wide and narrow viewing angle control module, including: the wide and narrow viewing angle control circuit described above; an input module, electrically connected to the wide and narrow viewing angle control circuit; a first power management module, connected to the wide and narrow viewing angle control circuit and the input module; a timing controller, connected to the first power management module.

[0014] According to still another aspect of the present invention, there is provided a display device, including the wide and narrow viewing angle control circuit as described above; the display device further includes a display panel, and the display panel is electrically connected to the wide and narrow viewing angle control circuit.

[0015] The width-variable and narrow-variable viewing angle control circuit, width-variable and narrow-variable viewing angle control module, and display device provided by the present utility model generate a dimming signal by using a second power management module, an operational amplifier module, a comparison module, etc., thereby saving a micro control unit and a digital-to-analog converter, and further saving the PCB cost and labor cost.

[0016] Furthermore, the width-variable and narrow-variable viewing angle control circuit, width-variable and narrow-variable viewing angle control module, and display device provided by the present utility model can make the design of the width-variable and narrow-variable viewing angle switching circuit of the display device with a width-variable and narrow-variable viewing angle switching function more diversified. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 The schematic structural diagram of the display device according to the embodiment of the present utility model is shown;

[0019] Figure 2 The schematic structural diagram of the width-variable and narrow-variable viewing angle display module according to the embodiment of the present utility model is shown;

[0020] Figure 3 The structural diagram of the width-variable and narrow-variable viewing angle display module according to the embodiment of the present utility model is shown;

[0021] Figure 4 The schematic structural diagram of the second power management module in the width-variable and narrow-variable viewing angle control circuit according to the embodiment of the present utility model is shown;

[0022] Figure 5 The schematic structural diagram of the control module in the width-variable and narrow-variable viewing angle control circuit according to the embodiment of the present utility model is shown;

[0023] Figure 6 The schematic structural diagram of the operational amplifier module in the width-variable and narrow-variable viewing angle control circuit according to the embodiment of the present utility model is shown;

[0024] Figure 7 The schematic structural diagram of the comparison module in the width-variable and narrow-variable viewing angle control circuit according to the embodiment of the present utility model is shown;

[0025] Figure 8a and Figure 8b The voltage waveform diagram of the comparison module in the width-variable and narrow-variable viewing angle control circuit according to the embodiment of the present utility model is shown;

[0026] Figure 9 The connection schematic diagram of the control module, the operational amplifier module, and the comparison module according to the embodiment of the present utility model is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Various embodiments of the present utility model 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 the sake of clarity, the various parts in the drawings are not drawn to scale.

[0028] The following will further describe in detail the specific implementation manners of the present utility model in conjunction with the accompanying drawings and embodiments.

[0029] Figure 1 The structural schematic diagram of a display device according to an embodiment of the present utility model is shown. Referring to Figure 1 , the display device 10 provided in the embodiment of the present application includes a printed circuit board 10, a display panel 20, and a connector 20 connecting the printed circuit board 10 and the display panel 20. Among them, a timing controller and other circuit structures are provided on the printed circuit board 10. A driving circuit for driving the display panel to achieve certain functions (such as a display function) is usually provided on the display panel 20, and relevant control circuits for controlling the operation of the driving circuit are provided on the printed circuit board 10. The driving circuit and the control circuit can be electrically connected through the connector 30. The connector can be, for example, a flexible printed circuit (FPC). Optionally, the printed circuit board 10 can be in the same plane as the display panel 20, or can be bent to the side away from the display surface of the display panel 20. The embodiment of the present utility model does not limit this.

[0030] Figure 2 The schematic structural diagram of a wide and narrow viewing angle display module according to an embodiment of the present utility model is shown. Figure 3 The structural schematic diagram of a wide and narrow viewing angle display module according to an embodiment of the present utility model is shown. Referring to Figure 2 , the wide and narrow viewing angle control module 100 of the present application is located on the printed circuit board 10. Specifically, the wide and narrow viewing angle control module 100 includes: an input module 110, a first power management module 120, a timing controller 130, a storage module 140, a second power management module 150, an operational amplifier module 160, a comparison module 170, a display panel 20, and a control module 190. Among them, the second power management module 150, the operational amplifier module 160, the comparison module 170, and the control module 190 cooperate to form a wide and narrow viewing angle control circuit to achieve the function of the microcontroller unit (MCU) in the switching of the wide and narrow viewing angles of the display device, thereby saving one microcontroller unit (MCU).

[0031] Specifically, in the wide and narrow viewing angle control module 100, the input module 110 is used to receive the DC voltage VIN and limit the current magnitude received by subsequent other modules through an insurance unit to cut off the circuit when the current magnitude of the DC voltage VIN exceeds the threshold to protect the subsequent other modules. Referring to Figure 3, the input module 110 includes a DC voltage module VIN, a first fuse unit Fuse1, a second fuse unit Fuse2, and a first resistor R1; the first fuse unit Fuse1 includes an input terminal and two output terminals, its input terminal is connected to the output terminal of the DC voltage module VIN, and its first output terminal is connected to the input terminal of the first power management module 120; the second fuse unit Fuse2 includes an input terminal and an output terminal, its input terminal is connected to the second output terminal of the first fuse unit Fuse1, and its output terminal is connected to the input terminal of the second power management module 150 via the first resistor R1. In this embodiment, the first fuse unit Fuse1 and the second fuse unit Fuse2 are, for example, fuses. When the current or voltage exceeds the rated value of the fuse unit, the fuse unit will blow and cut off the circuit, thereby protecting other electronic components from damage. The fuse unit plays a role in protecting the circuit and extending the life of the device in the display device.

[0032] The first power management module 120 is connected to the input module 110 and is used to manage and distribute the first input voltage, and convert the input voltage into the voltages and currents required by each module. For example, after receiving an input voltage of 3.3V, the first power management module 120 generates various voltages with different amplitudes such as an analog power supply voltage AVDD, a gamma voltage gamma, an XVCC, a high gate voltage VGH, a low gate voltage VGL, a first digital power supply voltage VDD11, a second numerical power supply voltage VDD18, and an I / O power supply voltage VDDIO. Specifically, the first power management module 120 is also connected to the source driver 210 and is used to provide voltage signals such as an analog power supply voltage AVDD, a gamma voltage gamma, an XVCC, a high gate voltage VGH, and a low gate voltage VGL to the source driver 210.

[0033] The timing controller 130 is connected to the first power management module 120 and receives the first digital power supply voltage VDD11, the second numerical power supply voltage VDD18, and the I / O power supply voltage VDDIO output by the first power management module 120. The timing controller 130 is responsible for controlling the refresh sequence and frequency of the pixels in the display panel to ensure that the image can be displayed on the screen in the correct sequence and rate. Further, refer to Figure 3 , the timing controller 130 is also used to generate a data transmission signal MSDA and a clock signal MSCL.

[0034] The storage module 140 is connected to the timing controller 130 and is used to store the configuration information and parameters of the display device, such as information on resolution, brightness, contrast, calibration data, user preferences, etc., so that these data can be quickly loaded when the display device is started, or these data can be retained after the device is restarted or powered off.

[0035] The second power management module 150 is connected to the input module 110 and the first power management module 120, and is used to manage and distribute the input voltage and the I / O power supply voltage VDDIO, and convert the input voltage and the I / O power supply voltage VDDIO into the voltages and currents required by the modules connected thereto. For example, the second power management module 150 includes at least three input terminals and two output terminals, and generates a positive voltage P5V (+5V) and a negative voltage N5V (-5V) after receiving the second input voltage limited by the input module 110 and the I / O power supply voltage VDDIO output by the first power management module 150.

[0036] Among them, the second power management module 150 uses a boost + charge bump integrated dual-channel power chip Dual Power IC, which can generate a positive voltage P5V (+5V) and a negative voltage N5V (-5V). Specifically, the structure of the second power management module 150 can refer to Figure 3 and Figure 4, the second power management module 150 includes a second resistor R2, a third resistor R3, first capacitors C1 to C6, a first inductor L1, and a first chip U1. The first chip U1 includes 13 pins. The first pin SW is connected to the input module 110 via the first inductor L1; the second pin PGND is connected to the ground terminal; the third pin VIN is connected to the input module 110; the fourth pin SDA is, for example, the second input terminal of the second power management module 150, and the fourth pin SDA is connected to the pin of the first power management module 120 that outputs the I / O power supply voltage VDDIO via the second resistor R2; the fifth pin EN is, for example, the first input terminal of the second power management module 150, and the fifth pin EN is connected to the input module 110; the sixth pin SCL is, for example, the third input terminal of the second power management module 150, and the sixth pin SCL is connected to the pin of the first power management module 120 that outputs the I / O power supply voltage VDDIO via the third resistor R3; the seventh pin OUTN is the second output terminal of the second power management module 150 for outputting a negative voltage N5V (-5V); the eighth pin CFLY2 is connected to the second end of the sixth capacitor C6; the ninth pin PGND is connected to the ground terminal; the tenth pin CFLY1 is connected to the first end of the sixth capacitor C6; the eleventh pin REG is connected to the ground terminal via the fifth capacitor C5; the twelfth pin OUTP is the first output terminal of the second power management module 150 for outputting a positive voltage P5V (+5V); the thirteenth pin AGND is connected to the ground terminal or left floating. In addition, the first end of the first capacitor C1 is connected to the first end of the first inductor L1, and the second end is grounded; the first end of the second capacitor C2 is connected to the first end of the first inductor L1, and the second end is connected to the second end of the first capacitor C1; the first end of the first inductor L1 is connected to the input module 110, and the second end is connected to the first pin SW of the first chip U1; the first end of the third capacitor C3 is connected to the seventh pin OUTN of the first chip U1, and the second end is grounded; the first end of the fourth capacitor C4 is connected to the twelfth pin OUTP of the first chip U1, and the second end is grounded.

[0037] The control module 190 is connected to the first power management module 120 and the second power management module 150, and is configured to generate wide and narrow control signals VP and VN according to the second numerical power supply voltage VDD18, the positive 5V voltage P5V, and the negative 5V voltage N5V. Among them, the wide and narrow control signal VP is used to output the positive voltage values of the wide control signal WVA and the narrow control signal NVA; the wide and narrow control signal VN is used to output the negative voltage values of the wide control signal WVA and the narrow control signal NVA.

[0038] Among them, refer to Figure 3 , Figure 5 and Figure 9, the control module 190 includes a viewing angle unit HVA, a first transistor T1 to a third transistor T3, an eighth resistor R8 to a twelfth resistor R12, a first current source VS1, a second current source VS2, and a first switch SW1. Specifically, the first end of the first switch SW1 is connected to the viewing angle unit HVA; the first end of the eighth resistor R8 is connected to the second end of the first switch SW1; the first end of the ninth resistor R9 is connected to the second end of the eighth resistor R8, and the second end is connected to the ground terminal; the control terminal of the first transistor T1 is connected to the first end of the ninth resistor R9, the first end is connected to the ground terminal, and the second end is connected to the first output terminal VP; the first end of the tenth resistor R10 is connected to the second end of the first transistor T1, and the second end is connected to the first output terminal P5V of the second power management module 150; the control terminal of the second transistor T2 is connected to the second end of the eighth resistor R8; the positive end of the first current source VS1 is connected to the first end of the second transistor T2, and the negative end is connected to the ground terminal; the first end of the eleventh resistor R11 is connected to the second end of the second transistor T2; the positive end of the second current source VS2 is connected to the second end of the eleventh resistor R11, and the negative end is connected to the ground terminal; the control terminal of the third transistor T3 is connected to the second end of the second transistor T2, the first end is connected to the ground terminal, and the second end is connected to the second output terminal VN; the first end of the twelfth resistor R12 is connected to the second end of the third transistor T3, and the second end is connected to the second output terminal N5V of the second power management module 150..

[0039] In this embodiment, the viewing angle unit HVA is used to control the on and off of the first switch SW1. When the signal output by the viewing angle unit HVA is at a low level L, the first switch SW1 is turned on and in an off state. At this time, the wide viewing angle signal WVA is output at the output terminal of the control module 190. Specifically, the signal voltage output at the first output terminal VP is +5V, and the signal voltage output at the second output terminal VN is -5V; when the signal output by the viewing angle unit HVA is at a high level H, the first switch SW1 is closed and in a conducting state. At this time, the narrow viewing angle signal NVA is output at the output terminal of the control module 190. Specifically, the signal voltage output at the first output terminal VP is 0V, and the signal voltage output at the second output terminal VN is 0V.

[0040] In addition, in the control module 190, the first transistor T1 is an NMOS transistor; the second transistor T2 and the third transistor T3 are PMOS transistors.

[0041] Further, the operational amplifier module 160 is connected to the second power management module 150 and the control module 190 and is used for signal amplification and filtering. In this embodiment, the operational amplifier module 160 adopts a dual-channel structure. For example, it is used to amplify and filter the width control signals VP and VN to generate the width and narrow viewing angle signals VPO and VNO. Among them, the width and narrow viewing angle signal VPO is used to output the positive voltage values of the wide control signal WVA and the narrow control signal NVA; the width and narrow viewing angle signal VNO is used to output the negative voltage values of the wide control signal WVA and the narrow control signal NVA.

[0042] Among them, referring to Figure 3 、 Figure 6 and Figure 9 , the operational amplifier module 160 includes the thirteenth resistor R13 to the sixteenth resistor R16, the first operational amplifier OP1, and the second operational amplifier OP2. The thirteenth resistor R13, the fourteenth resistor R14, and the first operational amplifier OP1 form the first channel of the operational amplifier module 160, and the fifteenth resistor R15, the sixteenth resistor R16, and the second operational amplifier OP2 form the second channel of the operational amplifier module 160.

[0043] Specifically, in the first channel of the operational amplifier module 160, the first end of the thirteenth resistor R13 is connected to the first output terminal P5V of the second power management module 150; the first end of the fourteenth resistor R14 is connected to the first output terminal VP of the control module 190, and the second end is connected to the second end of the thirteenth resistor R13; the first operational amplifier OP1 includes a positive input terminal, a negative input terminal, and an output terminal. Its positive input terminal is connected to the second end of the thirteenth resistor R13, the negative input terminal is connected to the output terminal, and the output terminal serves as the first output terminal VPO of the operational amplifier module 160. In the second channel of the operational amplifier module 160, the first end of the fifteenth resistor R15 is connected to the second output terminal N5V of the second power management module 150; the first end of the sixteenth resistor R16 is connected to the second output terminal VN of the control module 190, and the second end is connected to the second end of the fifteenth resistor R15; the second operational amplifier OP2 includes a positive input terminal, a negative input terminal, and an output terminal. Its positive input terminal is connected to the second end of the fifteenth resistor R15, the negative input terminal is connected to the output terminal, and the output terminal serves as the second output terminal VNO of the operational amplifier module 160.

[0044] In this embodiment, the voltage output by the first output terminal P5V of the second power management module 120 is +5V, and the voltage output by the second output terminal N5V is -5V. On this basis, when the signal output by the viewing angle unit HVA of the control module 190 is at a low level L, the signal voltage output by the first output terminal VP of the control module 190 is +5V, and the signal voltage output by the second output terminal VN is -5V. At this time, the first channel of the operational amplifier module 160 receives the signal of the first output terminal P5V of the second power management module 120 and the signal of the first output terminal VP of the control module 190. The signal output by the first output terminal VPO of the operational amplifier module 160 is a wide viewing angle signal WVA, and its amplitude is +5V; the second channel of the operational amplifier module 160 receives the signal of the second output terminal N5V of the second power management module 120 and the signal of the second output terminal VN of the control module 190. The signal output by the second output terminal VNO of the operational amplifier module 160 is a wide viewing angle signal WVA, and its amplitude is -5V. When the signal output by the viewing angle unit HVA of the control module 190 is at a high level H, the signal voltage output by the first output terminal VP of the control module 190 is 0V, and the signal voltage output by the second output terminal VN is 0V. At this time, the first channel of the operational amplifier module 160 receives the signal of the first output terminal P5V of the second power management module 120 and the signal of the first output terminal VP of the control module 190. The signal output by the first output terminal VPO of the operational amplifier module 160 is a narrow viewing angle signal NVA, and its amplitude is +2.5V; the second channel of the operational amplifier module 160 receives the signal of the second output terminal N5V of the second power management module 120 and the signal of the second output terminal VN of the control module 190. The signal output by the second output terminal VNO of the operational amplifier module 160 is a narrow viewing angle signal NVA, and its amplitude is -2.5V.

[0045] Further, the comparison module 170 is connected to the operational amplifier module 160, the first power management module 120, and the timing controller 130, and is configured to compare the voltage of the wide and narrow viewing angle signals output by the operational amplifier module 160 with a reference voltage to generate a dimming signal EQ for controlling the display effect of the display panel.

[0046] Among them, the reference Figure 3 、 Figure 7 and Figure 9, the comparison module 170 includes: a sixth resistor R6, a seventh resistor R7, a seventeenth resistor R17, and a comparator U2. Specifically, the sixth resistor R6 and the seventh resistor R7 are connected in series, and the first end of the sixth resistor R6 is connected to the first power management module 120 and the timing controller 130, and the second end of the seventh resistor R7 is connected to the ground terminal; the comparator U2 includes four input terminals and one output terminal. The first input terminal is the inverting input terminal of the comparator U2, which is connected to the connection midpoint of the sixth resistor R6 and the seventh resistor R7 for receiving the reference voltage Vrf; the second input terminal is the non-inverting input terminal of the comparator U2, which is connected to the timing controller 130 for receiving the square wave voltage; the third input terminal is the negative power supply terminal of the comparator U2, which is connected to the second output terminal VNO of the operational amplifier module 160; the fourth input terminal is the positive power supply terminal of the comparator U2, which is connected to the first output terminal VPO of the operational amplifier module 160. The output terminal of the comparator U2 is used to output a dimming signal EQ; the first end of the seventeenth resistor R17 is connected to the output terminal of the comparator U2, and the second end is connected to the ground terminal.

[0047] Reference Figure 8a and Figure 9 , when the signal output by the viewing angle unit HVA of the control module 190 is at a low level L, the first input terminal of the comparator U2 is the reference voltage signal Vrf, the second input terminal of the comparator U2 is the square wave signal of the timing controller 130, the third input terminal of the comparator U2 is the -5V voltage output by the second output terminal VNO of the operational amplifier module 160, and the fourth input terminal of the comparator U2 is the +5V voltage output by the first output terminal VPO of the operational amplifier module 160. Since the voltage value of the reference voltage signal Vrf is VDDIO / 2, the square wave signal of the timing controller 130 is a square wave signal with a duty cycle of 50% and a voltage value of 0 - VDDIO. At this time, if the second input terminal of the comparator U2 is at a high level of the square wave signal, the voltage of the second input terminal of the comparator U2 is greater than the voltage of the first input terminal, and the output terminal of the comparator U2 outputs the voltage value +5V of the fourth input terminal; if the second input terminal of the comparator U2 is at a low level of the square wave signal, the voltage of the second input terminal of the comparator U2 is less than the voltage of the first input terminal, and the output terminal of the comparator U2 outputs the voltage value -5V of the third input terminal.

[0048] Reference Figure 8b and Figure 9, when the signal output by the viewing angle unit HVA of the control module 190 is at a high level H, the third input terminal of the comparator U2 is the -2.5V voltage output by the second output terminal VNO of the operational amplifier module 160, and the fourth input terminal of the comparator U2 is the +2.5V voltage output by the first output terminal VPO of the operational amplifier module 160. Since the voltage value of the reference voltage signal Vrf is VDDIO / 2, the square wave signal of the timing controller 130 is a square wave signal with a duty cycle of 50% and a voltage value of 0 - VDDIO. At this time, if the second input terminal of the comparator U2 is at the high level of the square wave signal, then the voltage of the second input terminal of the comparator U2 is greater than the voltage of the first input terminal, and the output terminal of the comparator U2 outputs the voltage value +2.5V of the fourth input terminal; if the second input terminal of the comparator U2 is at the low level of the square wave signal at this time, then the voltage of the second input terminal of the comparator U2 is less than the voltage of the first input terminal, and the output terminal of the comparator U2 outputs the voltage value -2.5V of the third input terminal.

[0049] Further, refer to Figure 3 , the specific connection manner of the first end of the sixth resistor R6 of the comparison module 170 with the first power management module 120 and the timing controller 130 is as follows: the output terminal of the first power management module 120 that outputs the I / O power supply voltage VDDIO is connected to the first end of the sixth resistor R6; the output terminal of the timing controller 130 that outputs the data transmission signal MSDA is connected to the first end of the sixth resistor R6 via the fifth resistor R5; and the output terminal of the timing controller 130 that outputs the clock signal MSCL is connected to the first end of the sixth resistor R6 via the fourth resistor R4.

[0050] Further, the display panel 20 is connected to the comparison module 170, and is used to receive the dimming signal EQ and perform viewing angle switching according to the dimming signal EQ.

[0051] The wide and narrow viewing angle control circuit and the display device provided by the present utility model generate a dimming signal by using a second power management module, an operational amplifier module, a comparison module, etc., thereby saving a micro control unit and a digital-to-analog converter, and further saving the PCB cost and labor cost.

[0052] Further, the wide and narrow viewing angle control circuit and the display device provided by the present utility model can make the design of the viewing angle switching circuit of the display device with the wide and narrow viewing angle switching function more diversified.

[0053] As described above with reference to the embodiments of the present utility model, these embodiments do not describe all the details in detail, nor do they limit the utility model to the specific embodiments described. Obviously, many modifications and variations can be made based on the above description. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present utility model, so that those skilled in the relevant technical field can make good use of the present utility model and its modifications. The present utility model is only limited by the claims and their full scope and equivalents.

Claims

1. A wide and narrow viewing angle control circuit, characterized in that: The wide and narrow viewing angle control circuit controls the dimming signal of the display panel to switch between wide and narrow viewing angles, including: A control module receives a positive voltage and a negative voltage to generate a width control signal; An operational amplifier module, connected to the control module, receives the positive voltage, the negative voltage and the width and narrow control signal to generate a wide and narrow viewing angle signal; The comparison module is connected to the operational amplifier module, and receives the wide and narrow viewing angle signals to generate the dimming signal. After receiving the dimming signal, the display panel performs wide viewing angle image display or narrow viewing angle image display.

2. The wide and narrow viewing angle control circuit according to claim 1, characterized in that: Also includes: The second power management module is connected to the control module and the operational amplifier module, and receives an input voltage to generate the positive voltage and the negative voltage.

3. The wide and narrow viewing angle control circuit according to claim 2, characterized in that: The second power management module includes: The first chip comprises at least three input terminals and two output terminals, the first input terminal receives an input voltage, the first output terminal outputs the positive voltage, and the second output terminal outputs the negative voltage; a second resistor, wherein the second input terminal of the first chip receives an I / O power supply voltage via the second resistor; a third resistor, wherein the third input terminal of the first chip receives an I / O power supply voltage via the third resistor; a third capacitor, wherein a first end of the third capacitor is connected to the second output end of the first chip, and a second end of the third capacitor is connected to the ground end; A fourth capacitor, wherein a first end of the fourth capacitor is connected to the first output end of the first chip, and a second end of the fourth capacitor is connected to the ground end.

4. The wide and narrow viewing angle control circuit according to claim 3, characterized in that: The control module comprises: The viewing angle unit generates a high level or a low level; A first switch, wherein a first end of the first switch is connected to the viewing angle unit, and the first switch is disconnected after receiving a low level or is turned on after receiving a high level; an eighth resistor, a first end of the eighth resistor being connected to the second end of the first switch; a first transistor, wherein a control end of the first transistor is connected to the second end of the eighth resistor, a first end of the first transistor is connected to the ground end, and a second end of the first transistor is connected to the first output end; a tenth resistor, wherein a first end of the tenth resistor is connected to the second end of the first transistor, and a second end of the tenth resistor is connected to the first output end of the second power management module; a second transistor, wherein a control terminal of the second transistor is connected to a second terminal of the eighth resistor; a third transistor, wherein a control terminal of the third transistor is connected to the second terminal of the second transistor, a first terminal of the third transistor is grounded, and a second terminal of the third transistor is connected to the second output terminal; A twelfth resistor, wherein a first end of the twelfth resistor is connected to the second end of the third transistor, and a second end of the twelfth resistor is connected to the second output end of the second power management module.

5. The wide and narrow viewing angle control circuit according to claim 4, characterized in that: The operational amplifier module includes a first channel and a second channel.

6. The wide and narrow viewing angle control circuit according to claim 5, characterized in that: The first channel of the operational amplifier module includes: a thirteenth resistor, a first end of the thirteenth resistor being connected to the first output end of the second power management module; a fourteenth resistor, a first end of the fourteenth resistor being connected to the first output end of the control module, and a second end of the fourteenth resistor being connected to the second end of the thirteenth resistor; A first operational amplifier, comprising a positive input terminal, a negative input terminal and an output terminal, wherein the positive input terminal is connected to the second terminal of the thirteenth resistor, the negative input terminal is connected to the output terminal, and the output terminal is connected to the first output terminal of the operational amplifier module; The second channel of the operational amplifier module includes: a fifteenth resistor, a first end of the fifteenth resistor being connected to the second output end of the second power management module; a sixteenth resistor, a first end of the sixteenth resistor being connected to the second output end of the control module, and a second end of the sixteenth resistor being connected to the second end of the fifteenth resistor; The second operational amplifier includes a positive input terminal, a negative input terminal and an output terminal, wherein the positive input terminal is connected to the second end of the fifteenth resistor, the negative input terminal is connected to the output terminal, and the output terminal is connected to the second output terminal of the operational amplifier module.

7. The wide and narrow viewing angle control circuit according to claim 6, characterized in that: The comparison module also receives a reference voltage and a square wave voltage, and generates a dimming signal according to the reference voltage, the square wave voltage and the wide and narrow viewing angle signals.

8. The wide and narrow viewing angle control circuit according to claim 7, characterized in that: The comparison module comprises: A sixth resistor and a seventh resistor connected in series, wherein a first end of the sixth resistor is connected to the timing controller, and a second end of the seventh resistor is connected to the ground end; A comparator, comprising four input terminals and an output terminal, wherein the first input terminal is an inverting input terminal connected to the connection midpoint of the sixth resistor and the seventh resistor, the second input terminal is a positive input terminal receiving a square wave voltage, the third input terminal is a negative power supply terminal connected to the second output terminal of the operational amplifier module, the fourth input terminal is a positive power supply segment connected to the first output terminal of the operational amplifier module, and the output terminal outputs a dimming signal; A seventeenth resistor, wherein a first end of the seventeenth resistor is connected to the output end of the comparator, and a second end of the seventeenth resistor is connected to the ground end.

9. A wide and narrow viewing angle control module, characterized in that: include: The wide and narrow viewing angle control circuit according to any one of claims 1 to 8; An input module, electrically connected to the wide and narrow viewing angle control circuit; A first power management module connected to the wide and narrow viewing angle control circuit and the input module; A timing controller is connected to the first power management module.

10. A display device, characterized in that: The invention comprises the wide and narrow viewing angle control module as claimed in claim 9; The display device further includes a display panel, and the display panel is electrically connected to the wide and narrow viewing angle control circuit.

Images