CN221378927U

CN221378927U - Viewing angle switching control circuit of display device and display device

Info

Publication number: CN221378927U
Application number: CN202323123518.8U
Authority: CN
Inventors: 王敏
Original assignee: InfoVision Optoelectronics Kunshan Co Ltd
Current assignee: InfoVision Optoelectronics Kunshan Co Ltd
Priority date: 2023-11-20
Filing date: 2023-11-20
Publication date: 2024-07-19
Anticipated expiration: 2033-11-20

Abstract

The utility model discloses a visual angle switching control circuit of a display device and the display device, wherein the visual angle switching control circuit comprises: the switch selection circuit is characterized in that an input end receives a first power supply voltage, a control end receives a wide-narrow visual angle signal, and an output end outputs a voltage signal with amplitude corresponding to different level states of the wide-narrow visual angle signal; the positive power end of the comparator is coupled with the output end of the switch control circuit to receive the voltage signal, the negative power end is coupled to the reference ground, the positive input end receives the first square wave signal provided by the time sequence controller, the negative input end receives the reference voltage, and the output end outputs the second square wave signal; the positive input end of the first operational amplifier receives the second square wave signal, the negative input end receives the first intermediate voltage which is adjustable based on the wide-narrow visual angle signal, and the output end outputs the visual angle switching signal after the difference value between the second square wave signal and the first intermediate voltage is calculated. Therefore, the resources of the microcontroller are saved, and meanwhile, the stability of the MCU code debugging of the microcontroller is improved.

Description

Viewing angle switching control circuit of display device and display device

Technical Field

The present utility model relates to the field of display technologies, and in particular, to a viewing angle switching control circuit of a display device and a display device.

Background

LCDs (Liquid CRYSTAL DISPLAY, liquid crystal display devices) have many advantages of low power consumption, light weight, low radiation, etc., and thus have now substantially replaced conventional Cathode Ray Tube (CRT) displays. Currently, liquid crystal display devices are widely used in electronic devices such as high-definition digital televisions, desktop computers, notebook computers, tablet computers, cellular phones, digital cameras, and the like.

The Hybrid VIEWING ANGLE liquid crystal display device can switch between a wide viewing angle display mode and a narrow viewing angle display mode, so that different requirements of users on privacy and visual angles in different application scenes are met.

As shown in fig. 1, the waveform (+ -5V/+ -2.5V) required by the conventional view angle switching signal EQ is generated according to the scheme shown in fig. 1, the micro controller MCU performs code debugging through the I2C protocol, controls the view angle switching control circuit to generate a square wave of 0-3.3V, and biases the waveform by using the operational amplifier to obtain the view angle control signal in the final level range.

However, the above scheme adopts three components of the microcontroller MCU, the visual angle switching control circuit and the operational amplifier, so that the cost is high, meanwhile, the microcontroller MCU has the allocation of other functions of the HVA machine, the microcontroller MCU and the visual angle switching control circuit adopt IC communication, the valuable resources of the microcontroller MCU can be occupied, and meanwhile, the code debugging instability of the microcontroller MCU is increased.

Disclosure of utility model

In view of the above problems, an object of the present utility model is to provide a viewing angle switching control circuit of a display device and a display device, so as to save resources of a microcontroller MCU and increase stability of code debugging of the microcontroller MCU.

According to an aspect of the present invention, there is provided a viewing angle switching control circuit of a display device, the viewing angle switching control circuit including: the switch selection circuit is characterized in that an input end receives a first power supply voltage, a control end receives a wide-narrow visual angle signal, and an output end outputs a voltage signal with amplitude corresponding to different level states of the wide-narrow visual angle signal; the positive power end of the comparator is coupled with the output end of the switch control circuit to receive the voltage signal, the negative power end of the comparator is coupled to the reference ground, the positive input end receives the first square wave signal provided by the time sequence controller, the negative input end receives the reference voltage, and the output end outputs a second square wave signal; the difference solving unit comprises a first operational amplifier, wherein the positive input end of the first operational amplifier is coupled with the output end of the comparator so as to receive the second square wave signal, the negative input end of the first operational amplifier receives a first intermediate voltage which is adjustable based on the wide-narrow visual angle signal, and the output end of the first operational amplifier outputs a visual angle switching signal after the difference value between the second square wave signal and the first intermediate voltage is calculated.

Optionally, the switch selection circuit includes a first resistor, a first switching tube and a second resistor connected in series between a first power voltage terminal and a reference ground, the control terminal of the first switching tube is controlled by the wide-narrow visual angle signal, and the voltage signal is provided by the intermediate node of the first switching tube and the first resistor.

Optionally, the switch selection circuit further comprises: the third resistor and the second switching tube are connected in series between the first power supply voltage end and the reference ground, the middle node of the third resistor and the second switching tube is connected with the control end of the first switching tube, and the control end of the second switching tube receives the wide-narrow visual angle signal, wherein the first switching tube is a P-type switching tube, and the second switching tube is an N-type switching tube.

Optionally, the differencing unit further comprises: a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor, wherein the fourth resistor and the fifth resistor are connected in series between the output end of the comparator and the reference ground, and the intermediate nodes of the fourth resistor and the fifth resistor are coupled with the positive input end of the first operational amplifier; the sixth resistor is coupled between the output end of the second voltage division branch and the negative input end of the first operational amplifier, the seventh resistor is coupled between the negative input end of the first operational amplifier and the output end, and the resistance values of the fourth resistor, the fifth resistor, the sixth resistor and the seventh resistor are equal.

Optionally, the differencing unit further comprises: the third switching tube is an N-type switching tube, a control end tube of the third switching tube receives the wide-narrow visual angle signal, the resistance values of the eighth resistor and the ninth resistor are equal, and an intermediate node of the third switching tube and the eighth resistor is coupled with a negative input end of the first operational amplifier so as to provide the first intermediate voltage.

Optionally, the first power supply voltage value is twice the second power supply voltage value.

Optionally, the first power supply voltage is 10V, the second power supply voltage is 5V, and the reference voltage is 1.8V or 2.5V.

Optionally, when the wide-narrow view angle signal is at a high level, the first switch tube and the second switch tube are turned on, and the amplitude of the voltage signal is a voltage division value of the first power supply voltage through the first resistor and the second resistor; the third switch tube is conducted, and the amplitude of the first intermediate voltage is the voltage division value of the second power supply voltage through the eighth resistor and the ninth resistor.

Optionally, when the wide-narrow view angle signal is at a low level, the first switching tube and the second switching tube are turned off, and the amplitude of the voltage signal is the first power supply voltage value; and the third switching tube is conducted, and the amplitude of the first intermediate voltage is the second power supply voltage value.

According to another aspect of the present invention, there is provided a display device including: the visual angle switching control circuit generates a corresponding visual angle switching signal according to the received wide and narrow visual angle signals; and the visual angle switching module is coupled with the visual angle switching control circuit, receives the visual angle switching signal and works in a corresponding mode.

The visual angle switching control circuit provided by the application avoids the workflow of communication with a microcontroller, and can realize the provision of different visual angle switching signals under the control of the wide and narrow visual angle signals HVA. The application effectively reduces the use of the microcontroller in the display device, and the visual angle switching control circuit has simple structure and smaller occupied area, effectively reduces the production cost, simultaneously reduces the use of the communication port, and is beneficial to the development and adaptation of new functions.

Alternatively, the high-low level of the viewing angle switching signal can be changed by adjusting the voltage supplied from the first power supply voltage to the second power supply voltage in the switch selection circuit. Therefore, the visual angle switching circuit provided by the application can flexibly adjust parameters according to the requirements of actual application scenes, and has better applicability.

Drawings

The above and other objects, features and advantages of the present utility model will become more apparent from the following description of embodiments of the present utility model with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic block diagram of view switching according to the prior art;

fig. 2 shows a block diagram of a display device according to an embodiment of the present application;

Fig. 3 shows a circuit diagram of a viewing angle switching control circuit according to an embodiment of the present application;

Fig. 4 shows a node circuit diagram of a view angle switching control circuit according to an embodiment of the present application;

Fig. 5a is a waveform diagram of a viewing angle switching control signal HVA; fig. 5b shows a waveform diagram of an output signal of the viewing angle switching control circuit;

Detailed Description

Various embodiments of the present utility model will be described in more detail below with reference to the accompanying drawings. The same elements or modules are denoted by the same or similar reference numerals in the various figures. For clarity, the various features of the drawings are not drawn to scale.

It should be appreciated that in the following description, a "circuit" may include a single or multiple combined hardware circuits, programmable circuits, state machine circuits, and/or elements capable of storing instructions for execution by the programmable circuits. When an element or circuit is referred to as being "connected to" another element or circuit is "connected between" two nodes, it can be directly coupled or connected to the other element or intervening elements may be present, the connection between the elements may be physical, logical, or a combination thereof. In contrast, when an element is referred to as being "directly coupled to" or "directly connected to" another element, it means that there are no intervening elements present between the two.

Also, certain terms are used throughout the description and claims to refer to particular components. It will be appreciated by those of ordinary skill in the art that a hardware manufacturer may refer to the same component by different names. The present patent specification and claims do not take the form of an element or components as a functional element or components as a rule.

Furthermore, it should be noted that relational terms such as first and second are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Fig. 2 shows a block diagram of a display device according to an embodiment of the present application.

The display device 200 includes a display array 210, a viewing angle switching control circuit 220, a viewing angle switching module 230, a timing control circuit, a gate driving circuit, a source driving circuit, and a backlight panel, which are not shown in the drawing.

The display array 210 includes a plurality of pixel units arranged in an array, and each pixel unit mainly includes a thin film transistor (Thin Film Transistor, TFT), a storage capacitor, and a liquid crystal capacitor. Each pixel unit is connected with the grid driving circuit through a grid line and connected with the source driving circuit through a source line. In response to the gate driving signal supplied through the gate line, the pixel unit may receive a data signal through the data line, store the data signal in the storage capacitor, and thereby display brightness corresponding to the data signal.

The viewing angle switching control circuit 220 provides the corresponding viewing angle switching signal VEQ to the viewing angle switching module 230 according to the received wide-narrow viewing angle signal HVA, thereby controlling the display device 200 to operate in any one of the wide-viewing angle display mode and the narrow-viewing angle display mode.

In addition, the display device further includes: the timing control circuit is used for controlling the grid driving circuit and the source driving circuit. The timing control circuit may receive an externally provided control signal (e.g., a control signal including a clock signal) and generate a gate control signal and a data control signal based on the control signal.

The gate driving circuit may receive a gate control signal from the timing control circuit, generate a gate driving signal based on the gate control signal, and supply the gate driving signal to the corresponding gate line.

The source driving circuit may receive the source control signal and the frame data from the timing control circuit, generate a data signal corresponding to the frame data, and supply the data signal to the corresponding data line.

The backlight panel is used to provide backlight to the display array 210.

Fig. 3 shows a circuit diagram of a viewing angle switching control circuit according to an embodiment of the present application.

Fig. 3 shows a schematic circuit diagram of the view angle switching control circuit 220 in fig. 2. Fig. 4 shows a node circuit diagram of a view angle switching control circuit according to an embodiment of the present application, and the two diagrams are combined.

The viewing angle switching control circuit 220 includes a switch selection circuit 221, a comparator 222, and a difference unit 223.

The switch selection circuit 221 has an input terminal receiving the first power voltage VS1, a control terminal receiving the wide-narrow viewing angle signal HVA, and an output terminal outputting a voltage signal having a magnitude corresponding to a different level state of the viewing angle switching signal.

The switch selection circuit 221 includes a first resistor R1, a second resistor R2, a third resistor R3, a first switching tube T1, and a second switching tube T2.

The first resistor R1, the first switching tube T1 and the second resistor R2 are connected in series between a first power voltage end and a reference ground, a control end of the first switching tube T1 is controlled by a wide-narrow visual angle signal HVA, and a node between the first switching tube T1 and the first resistor R1 provides the voltage signal.

The third resistor R3 and the second switch tube T2 are connected in series between the first power supply voltage end and the reference ground, the middle node of the third resistor R3 and the second switch tube T2 is connected with the control end of the first switch tube T1, and the control end of the two switch tube T2 receives the wide-narrow visual angle signal HVA.

In one embodiment, the first switching tube T1 is a P-type switching tube, the second switching tube T2 is an N-type switching tube, and the first power supply voltage VS1 may be, for example, a 10V power supply voltage obtained from a conventional power supply voltage of 3.3V through a Boost chip. The resistance of the first resistor R1 is equal to the resistance of the second resistor R2.

When the wide-narrow viewing angle signal HVA is at a high level, the second switching tube T2 is turned on, so that the control end of the second switching tube T2 is coupled to the reference ground, i.e. the point B potential is 0V, and the first switching tube T1 is turned on, and at this time, the potential of the first conducting end of the first switching tube T1, i.e. the point C potential is 5V, is output to the comparator 222 through the voltage division between the first resistor R1 and the second resistor R2.

When the wide-narrow viewing angle signal HVA is at a low level, the second switching tube T2 is turned off, so that the control end of the second switching tube T2 receives the first power voltage, i.e. the point B potential is 10V, and the first switching tube T1 is turned off, and at this time, the first conducting end potential of the first switching tube T1 is the first power voltage VS1, i.e. the point C potential is 10V, and the first power voltage is output to the comparator 222.

The positive power terminal of the comparator 222 is coupled to the output terminal of the switch selection circuit 221 to receive the voltage signal, the negative power terminal is coupled to the reference ground, the positive input terminal receives the square wave signal provided by the time sequence controller TCON, the negative input terminal receives the reference voltage Vref, and the output terminal outputs the second square wave signal, and the reference voltage Vref is, for example, 2.5V or 1.8V.

The positive input end of the comparator 222 receives the square wave signal provided by the timing controller TCON, the negative input end receives the reference voltage Vref, and when the voltage of the positive input end is higher than that of the negative input end, the comparator outputs a high level (corresponding to the voltage signal received by the positive power supply end); if the voltage at the positive input is lower than the voltage at the negative input, the comparator outputs a low level (corresponding to 0V referenced to ground). That is, when the wide-narrow viewing angle signal HVA is at a low level and the voltage signal amplitude is 10V, the comparator 222 outputs a square wave signal of 0V to 10V at the output terminal (corresponding to the point D potential); and when the wide-narrow viewing angle signal HVA is at a high level and the voltage signal amplitude is 5V, the comparator 222 outputs a square wave signal of 0V-5V at the output terminal (corresponding to the point D potential).

The difference unit 223 includes an operational amplifier OPA1, a third switching tube T3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9.

The fourth resistor R4 and the fifth resistor R5 are connected in series between the output end of the comparator 222 and the reference ground, and the intermediate node between the fourth resistor R4 and the fifth resistor R5 is coupled to the positive input end of the operational amplifier OPA 1;

The seventh resistor R7 is coupled between the negative input terminal and the output terminal of the operational amplifier OPA 1. The eighth resistor R8, the ninth resistor R9 and the third switching tube T3 are connected in series between the second power voltage VS2 and the reference ground, and the control end of the third switching tube T3 receives the wide-narrow viewing angle signal HVA. The sixth resistor R6 is coupled between the intermediate nodes of the eighth resistor R8 and the ninth resistor R9 and the negative input terminal of the operational amplifier OPA 1.

In one embodiment, the second power voltage VS2 may generate a voltage of 5V by the first power voltage VS1 using a voltage dividing resistor. The third switching tube T3 is, for example, an N-type switching tube. The resistance values of the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 are equal.

When the parallel equivalent resistance of the fourth resistor R4 and the fifth resistor R5 is the same as the parallel equivalent resistance of the sixth resistor R6 and the seventh resistor R7, and the resistance values of the fifth resistor R5 and the sixth resistor R6 are the same as the seventh resistor R7, the viewing angle switching signal VEQ is equal to the difference between the point D potential and the point E potential.

When the wide-narrow viewing angle signal HVA is at a high level, the comparator 222 outputs a square wave signal of 0V-5V at the output terminal (corresponding to the point D potential); the third switching tube T3 is turned on, the voltage at the point E is obtained by dividing the second power voltage VS2 by the eighth resistor R8 and the ninth resistor R9, and is 2.5V, and at this time, the output end of the operational amplifier OPA1 outputs a ±2.5v square wave signal, and is provided as the viewing angle switching signal VEQ to the viewing angle switching module 230.

When the wide-narrow viewing angle signal HVA is at low level, the comparator 222 generates a square wave signal of 0V-10V at the output (corresponding to the point D potential); the third switching tube T3 is conducted, and the potential at the point E is the second power supply voltage VS2, namely 5V. At this time, the output terminal of the operational amplifier OPA1 outputs ±5v square wave signals and is provided to the viewing angle switching module 230 as the viewing angle switching signal VEQ.

The potential of each node is shown in the following table I:

HVA

T3(NMOS)

Node B

T1(PMOS)

Node C (VS+)

Node D

T4(NMOS)

Node E

Output

H

Conduction

GND

Conduction

5V

0-5V square wave

Conduction

2.5V

2.5V square wave

L

Cut-off

10V

Cut-off

10V

Square wave of 0-10V

Cut-off

5V

5V square wave

List one

Fig. 5a is a waveform diagram of a viewing angle switching control signal HVA; fig. 5b shows a waveform diagram of an output signal of the viewing angle switching control circuit.

As shown in fig. 5a and 5b, the viewing angle switching control circuit provided by the present application avoids a workflow of communication with a microcontroller, and can provide different viewing angle switching signals under the control of the wide-narrow viewing angle signal HVA. The application effectively reduces the use of the microcontroller in the display device, and the visual angle switching control circuit has simple structure and smaller occupied area, effectively reduces the production cost, simultaneously reduces the use of the communication port, and is beneficial to the development and adaptation of new functions.

Alternatively, the high and low levels of the viewing angle switching signal VEQ can be changed by adjusting the supplied first and second power voltages VS1 and VS 2. Therefore, the visual angle switching circuit provided by the application can flexibly adjust parameters according to the requirements of actual application scenes, and has better applicability.

It should be noted that the words "during", "when" and "when … …" as used herein in relation to circuit operation are not strict terms indicating an action that occurs immediately upon the start of a start-up action, but rather there may be some small but reasonable delay or delays between it and the reaction action (reaction) initiated by the start-up action, such as various transmission delays and the like, as will be appreciated by those of ordinary skill in the art. The word "about" or "substantially" is used herein to mean that an element value (element) has a parameter that is expected to be close to the stated value or position. However, as is well known in the art, there is always a slight deviation such that the value or position is difficult to strictly assume the stated value. It has been well established in the art that deviations of at least ten percent (10%) (at least twenty percent (20%)) for semiconductor doping concentrations are reasonable deviations from the exact ideal targets described. When used in connection with a signal state, the actual voltage value or logic state of the signal (e.g., "1" or "0") depends on whether positive or negative logic is used.

Embodiments in accordance with the present utility model, as described above, are not intended to be exhaustive or to limit the utility model to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, to thereby enable others skilled in the art to best utilize the utility model and various modifications as are suited to the particular use contemplated. The scope of the utility model should be determined by the appended claims and their equivalents.

Claims

1. A viewing angle switching control circuit of a display device, the viewing angle switching control circuit comprising:

The switch selection circuit is characterized in that an input end receives a first power supply voltage, a control end receives a wide-narrow visual angle signal, and an output end outputs a voltage signal with amplitude corresponding to different level states of the wide-narrow visual angle signal;

The positive power end of the comparator is coupled with the output end of the switch selection circuit to receive the voltage signal, the negative power end of the comparator is coupled to the reference ground, the positive input end of the comparator receives the first square wave signal provided by the time sequence controller, the negative input end of the comparator receives the reference voltage, and the output end of the comparator outputs a second square wave signal;

The difference solving unit comprises a first operational amplifier, wherein the positive input end of the first operational amplifier is coupled with the output end of the comparator so as to receive the second square wave signal, the negative input end of the first operational amplifier receives a first intermediate voltage which is adjustable based on the wide-narrow visual angle signal, and the output end of the first operational amplifier outputs a visual angle switching signal after the difference value between the second square wave signal and the first intermediate voltage is calculated.

2. The view angle switching control circuit of claim 1, wherein the switch selection circuit comprises a first resistor, a first switching tube and a second resistor connected in series between a first power supply voltage terminal and a reference ground, the first switching tube control terminal being controlled by the wide-narrow view angle signal, the first switching tube and the first resistor intermediate node providing the voltage signal.

3. The viewing angle switching control circuit of claim 2, wherein the switch selection circuit further comprises: the third resistor and the second switching tube are connected in series between the first power supply voltage end and the reference ground, the middle node of the third resistor and the second switching tube is connected with the control end of the first switching tube, the control ends of the two switching tubes receive the wide-narrow visual angle signals,

The first switching tube is a P-type switching tube, and the second switching tube is an N-type switching tube.

4. The viewing angle switching control circuit according to claim 3, wherein the differencing unit further comprises: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor,

The fourth resistor and the fifth resistor are connected in series between the output end of the comparator and the reference ground, and the intermediate node of the fourth resistor and the fifth resistor is coupled with the positive input end of the first operational amplifier;

The sixth resistor is coupled between the output end of the second voltage division branch and the negative input end of the first operational amplifier, the seventh resistor is coupled between the negative input end of the first operational amplifier and the output end,

And the resistance values of the fourth resistor, the fifth resistor, the sixth resistor and the seventh resistor are equal.

5. The viewing angle switching control circuit of claim 4, wherein the differencing unit further comprises:

an eighth resistor, a third switching tube and a ninth resistor which are connected in series between the second power supply voltage end and the reference ground, wherein the third switching tube is an N-type switching tube, a control end tube of the third switching tube receives the wide-narrow visual angle signal, the resistance values of the eighth resistor and the ninth resistor are equal,

The intermediate node of the third switching tube and the eighth resistor is coupled with the negative input end of the first operational amplifier so as to provide the first intermediate voltage.

6. The view angle switching control circuit of claim 5, wherein the magnitude of the first power supply voltage is twice the magnitude of the second power supply voltage.

7. The viewing angle switching control circuit of claim 6, wherein the first power supply voltage is 10V, the second power supply voltage is 5V, and the reference voltage is 1.8V or 2.5V.

8. The viewing angle switching control circuit of claim 6, wherein when the wide and narrow viewing angle signals are high,

The first switch tube and the second switch tube are conducted, and the amplitude of the voltage signal is the voltage division value of the first power supply voltage through the first resistor and the second resistor;

The third switch tube is conducted, and the amplitude of the first intermediate voltage is the voltage division value of the second power supply voltage through the eighth resistor and the ninth resistor.

9. The viewing angle switching control circuit of claim 6, wherein when the wide and narrow viewing angle signals are low,

The first switching tube and the second switching tube are turned off, and the amplitude of the voltage signal is the first power supply voltage value;

And the third switching tube is conducted, and the amplitude of the first intermediate voltage is the second power supply voltage value.

10. A display device, comprising: the viewing angle switching control circuit of any one of claims 1 to 9, generating a corresponding viewing angle switching signal from the received wide-narrow viewing angle signal; and

And the visual angle switching module is coupled with the visual angle switching control circuit, receives the visual angle switching signal and works in a corresponding mode.