Liquid crystal display light source contrast detection system

Abstract

The utility model relates to the technical field of liquid crystal display screen detection, and discloses a liquid crystal display screen light source contrast detection system, which comprises a control circuit, a power supply circuit, a light source driving circuit, a self-adaptive light source adjusting circuit, an image acquisition circuit, a signal processing circuit, an image contrast calculation circuit, an LCD display driving circuit and a serial port communication circuit, through the design of the self-adaptive light source adjusting circuit, the brightness distribution and color change of the liquid crystal display screen can be analyzed in real time, the brightness and spectral distribution of the light source can be automatically adjusted, the optimal contrast detection condition is ensured, the light source is dynamically adjusted according to the actual state of the display screen, and the detection accuracy and stability are improved; through the design of the image contrast calculation circuit, the amplification value of the video signals and the relative value between the signals can be adjusted, namely, the brightness and the contrast of the video can be adjusted, and the image processing capability is further improved, namely, the accuracy and the stability of detection are further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal display screen detection, in particular to a liquid crystal display screen light source contrast detection system. Background Art

[0002] Liquid crystal displays are flat, thin display devices that consist of a certain number of color or black and white pixels placed in front of a light source or reflective surface. LCD displays are low power, so they are favored by engineers and are suitable for battery-powered electronic devices.

[0003] Light source contrast detection is an important machine vision and image processing technology used to evaluate the performance of light sources in specific application scenarios. When performing light source contrast detection, it is usually necessary to consider multiple characteristics of the light source, including brightness, uniformity, robustness, maintainability, lifespan, and heat generation.

[0004] After searching, the patent with application number CN202021720030.7 discloses a liquid crystal display light source detection system, which includes a housing, a controller, a light transmitter, a light receiver and a display module; the controller is installed on the housing; the light transmitter is arranged on the housing, the light transmitter is connected to the controller and is used to transmit test light to the liquid crystal display; the light receiver is arranged on the housing and is used to receive the reflected light emitted by the test light emitted by the light transmitter through the liquid crystal display; the display module is arranged on the housing and connected to the controller; the controller is used to determine the contrast value of the liquid crystal display according to the reflected light and display the contrast value through the display module. This utility model proposes a liquid crystal display light source detection system, which realizes the detection of the contrast of the backlight source of the liquid crystal display so as to adjust the contrast value of the liquid crystal display, so that the liquid crystal display can obtain a better display effect.

[0005] Currently, when performing light source contrast detection on LCD screens, the contrast of the light source is mostly detected under the same brightness of the light source. Since the brightness distribution and color of the display screen are changing during the detection, the light source cannot be dynamically adjusted according to the actual state of the display screen, which reduces the accuracy of the detection. Therefore, we need to propose a liquid crystal display light source contrast detection system. Utility Model Content

[0006] The utility model aims to provide a liquid crystal display light source contrast detection system. Through the design of an adaptive light source adjustment circuit, the brightness distribution and color change of the liquid crystal display can be analyzed in real time, and the brightness and spectral distribution of the light source can be automatically adjusted to ensure the best contrast detection conditions, and the light source can be dynamically adjusted according to the actual state of the display screen to improve the accuracy and stability of the detection; through the design of an image contrast calculation circuit, the amplification value of the video signal and the relative value between the signals can be adjusted, that is, the brightness and contrast of the video can be adjusted, and the image processing capability can be further improved, that is, the accuracy and stability of the detection can be further improved to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a liquid crystal display light source contrast detection system, comprising a control circuit, a power supply circuit, a light source driving circuit for providing a controllable light source for a liquid crystal display, an adaptive light source adjustment circuit for dynamically adjusting the light source according to the actual state of the display, an image acquisition circuit for converting analog signals into digital signals, a signal processing circuit for preprocessing the acquired image signals, an image contrast calculation circuit, an LCD display driving circuit for displaying contrast detection results, and a serial communication circuit for outputting the detection results;

[0008] The power supply circuit and the control circuit are both electrically connected to the light source driving circuit, the adaptive light source adjustment circuit, the image acquisition circuit, the signal processing circuit, the image contrast calculation circuit, the LCD display driving circuit and the serial communication circuit, and the power supply circuit is electrically connected to the control circuit.

[0009] Preferably, the light source driving circuit comprises a chip U1, pin 1 of the chip U1 is connected to a light emitting diode LED1 connected to a power supply in a power supply circuit, and pin 5 of the chip U1 is connected to a grounded resistor R1.

[0010] Preferably, the adaptive light source adjustment circuit includes a chip U10 and a MOS tube Q1, resistors R7, R11, R6 and R12 are arranged in parallel between pin 1 and pin 2 of the chip U10, resistor R10 is connected between the gate G of the MOS tube Q1 and pin 6 of the chip U1, the drain D of the MOS tube Q1 is connected to pin 1 of the chip U1, and the source S of the MOS tube Q1 is connected to diodes D4, D2 and D3 arranged in parallel.

[0011] Preferably, the image acquisition circuit includes a chip U22, a chip U11 and a terminal J1, a resistor R17 is connected between pin 1 and pin 5 of the chip U22, and a grounded capacitor C5 is connected to pin 5 of the chip U22, a grounded resistor R57 is connected to pin 2 of the chip U22, a capacitor C3 is connected between pin 1 and pin 2 of the chip U11, a capacitor C6 and a capacitor C4 are connected in parallel between pin 1 and pin 3 of the chip U11, and a resistor R47 and a resistor R37 connected to a power supply are connected between pin 3 and pin 4 of the terminal J1.

[0012] Preferably, the signal processing circuit includes an amplifier U2A and an amplifier U2B, a capacitor C42 and a resistor R56 are connected between pin 1 of the amplifier U2A and pin 6 of the amplifier U2B, a capacitor C22 connected to ground and connected to a power supply is connected to pin 4 of the amplifier U2A, a resistor R36 is connected to pin 3 of the amplifier U2A, a resistor C26 and a capacitor C12 are connected to pin 2 of the amplifier U2A in sequence, and a resistor R46 and a capacitor C32 are connected in parallel between pin 1 and pin 2 of the amplifier U2A;

[0013] A resistor R66 is connected to the pin 5 of the amplifier U2B, and a resistor R76 and a capacitor C52 are connected in parallel between the pins 6 and 7 of the amplifier U2B.

[0014] Preferably, the image contrast calculation circuit includes a chip U3, an amplifier U3A and an amplifier U3B, pin 1 of the chip U3 is connected to a resistor R78 and a diode D13 arranged in parallel, and the connection terminals of the resistor R78 and the diode D13 are connected to a grounded capacitor C43, pin 3 of the chip U3 is connected to a capacitor C53, one end of the capacitor C53 is connected to a diode D23 and a resistor R88 arranged in parallel, resistor R28, resistor R18 and capacitor C13 are connected between pin 2 of the chip U3 and pin 1 of the amplifier U3B, resistor R38 is connected between pin 1 and pin 5 of the amplifier U3B, pin 2 of the amplifier U3B is connected to pins 10 and 6 of the amplifier U3A, and pin 7 of the amplifier U3A is connected to a resistor R48 connected to a power supply and a resistor R58 connected to ground.

[0015] Preferably, the LCD display drive circuit includes a chip U4, an inductor L3 is connected between pin 1 and pin 6 of the chip U4, a diode D12 is connected between pin 1 and pin 5 of the chip U4, and a grounded capacitor C43 is connected to the connection terminals of the inductor L3 and the diode D12, a capacitor C41 and a capacitor C420 arranged in parallel are connected to pin 5 of the chip U4, and a capacitor C40, a capacitor C39 and a capacitor C38 arranged in parallel are connected to pin 6 of the chip U4;

[0016] A resistor R44 is connected between pin 4 and pin 2 of the chip U4, and a resistor R42 is connected to pin 4 of the chip U4, a resistor R43 is connected to pin 3 of the chip U4, one end of the resistor R43 is connected to a resistor R53, the other end of the resistor R43 is connected to resistors R54 and R55 arranged in parallel, one end of the resistor R54 is respectively connected to a resistor R56 and a capacitor C45, and one end of the resistor R56 is connected to a resistor R45.

[0017] Preferably, the serial communication circuit includes a chip U21 and a terminal J2, a capacitor C19 is connected between pin 1 and pin 3 of the chip U21, a capacitor C49 is connected between pin 2 and pin 16 of the chip U21, a capacitor C29 is connected between pin 4 and pin 5 of the chip U21, a capacitor C390 is connected between pin 6 and pin 15 of the chip U21, pin 13 of the chip U21 is connected to pin 3 of the terminal J2, and pin 14 of the chip U21 is connected to pin 2 of the terminal J2.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. The utility model can analyze the brightness distribution and color changes of the LCD screen in real time through the design of the adaptive light source adjustment circuit, automatically adjust the brightness and spectral distribution of the light source to ensure the best contrast detection conditions, and dynamically adjust the light source according to the actual state of the display screen to improve the accuracy and stability of the detection;

[0020] 2. The utility model can adjust the amplification value of the video signal and the relative value between the signals through the design of the image contrast calculation circuit, that is, it can adjust the brightness and contrast of the video, further improve the image processing capability, that is, further improve the accuracy and stability of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a circuit diagram of the light source driving circuit of the utility model;

[0022] Figure 2 This is a circuit diagram of the adaptive light source adjustment circuit of the utility model;

[0023] Figure 3 It is a circuit diagram of the image acquisition circuit of the utility model;

[0024] Figure 4 A circuit diagram of a signal processing circuit of the utility model;

[0025] Figure 5 The circuit diagram of the image contrast calculation circuit of the utility model;

[0026] Figure 6This is a circuit diagram of the LCD display drive circuit of the utility model;

[0027] Figure 7 It is a circuit diagram of the serial communication circuit of the utility model;

[0028] Figure 8 This is a system block diagram of the utility model. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] See also Figure 1-8 The utility model provides a technical solution: a liquid crystal display light source contrast detection system, including a control circuit, a power supply circuit, a light source driving circuit for providing a controllable light source for a liquid crystal display, an adaptive light source adjustment circuit for dynamically adjusting the light source according to the actual state of the display, an image acquisition circuit for converting analog signals into digital signals, a signal processing circuit for preprocessing the acquired image signals, an image contrast calculation circuit, an LCD display driving circuit for displaying contrast detection results, and a serial communication circuit for outputting the detection results;

[0031] The power supply circuit and the control circuit are both electrically connected to the light source driving circuit, the adaptive light source adjustment circuit, the image acquisition circuit, the signal processing circuit, the image contrast calculation circuit, the LCD display driving circuit and the serial communication circuit, and the power supply circuit is electrically connected to the control circuit.

[0032] The light source driving circuit comprises a chip U1 , a light emitting diode LED1 connected to a power source in a power supply circuit is connected to pin 1 of the chip U1 , and a resistor R1 connected to a ground is connected to pin 5 of the chip U1 .

[0033] The adaptive light source adjustment circuit includes a chip U10 and a MOS tube Q1. Resistors R7, R11, R6 and R12 are arranged in parallel between pin 1 and pin 2 of the chip U10. Resistors R10 are connected between a gate G of the MOS tube Q1 and pin 6 of the chip U1. A drain D of the MOS tube Q1 is connected to pin 1 of the chip U1. A diode D4, a diode D2 and a diode D3 arranged in parallel are connected to a source S of the MOS tube Q1.

[0034] A resistor R8 is connected between pins 3 and 4 of the chip U10, and a grounded capacitor C1 is connected to pin 3 of the chip U10. Resistors R2, R101 and capacitor C2 are connected between pins 2 and 3 of the chip U10, and a resistor R4 is connected to pin 5 of the chip U10.

[0035] The image acquisition circuit includes a chip U22, a chip U11 and a terminal J1. A resistor R17 is connected between pin 1 and pin 5 of the chip U22, and a grounded capacitor C5 is connected to pin 5 of the chip U22. A grounded resistor R57 is connected to pin 2 of the chip U22. A capacitor C3 is connected between pin 1 and pin 2 of the chip U11. A capacitor C6 and a capacitor C4 are connected in parallel between pin 1 and pin 3 of the chip U11. A resistor R47 and a resistor R37 connected to a power supply are connected between pin 3 and pin 4 of the terminal J1.

[0036] The signal processing circuit includes an amplifier U2A and an amplifier U2B, a capacitor C42 and a resistor R56 are connected between pin 1 of the amplifier U2A and pin 6 of the amplifier U2B, a capacitor C22 connected to ground and connected to a power supply is connected to pin 4 of the amplifier U2A, a resistor R36 is connected to pin 3 of the amplifier U2A, a resistor C26 and a capacitor C12 are connected to pin 2 of the amplifier U2A in sequence, and a resistor R46 and a capacitor C32 are connected in parallel between pin 1 and pin 2 of the amplifier U2A;

[0037] A resistor R66 is connected to the pin 5 of the amplifier U2B, and a resistor R76 and a capacitor C52 are connected in parallel between the pins 6 and 7 of the amplifier U2B.

[0038] The image contrast calculation circuit includes a chip U3, an amplifier U3A and an amplifier U3B. Pin 1 of the chip U3 is connected to a resistor R78 and a diode D13 arranged in parallel, and the connection terminals of the resistor R78 and the diode D13 are connected to a grounded capacitor C43. Pin 3 of the chip U3 is connected to a capacitor C53, and one end of the capacitor C53 is connected to a diode D23 and a resistor R88 arranged in parallel. Resistors R28, R18 and capacitor C13 are connected between pin 2 of the chip U3 and pin 1 of the amplifier U3B. Resistors R38 are connected between pins 1 and 5 of the amplifier U3B. Pin 2 of the amplifier U3B is connected to pins 10 and 6 of the amplifier U3A. Pin 7 of the amplifier U3A is connected to a resistor R48 connected to a power supply and a resistor R58 connected to ground.

[0039] Pin 5 of chip U3 is connected to the power supply and is connected to a grounded capacitor C23. Pin 7 of chip U3 is connected to a resistor R68 and a capacitor C33 connected in parallel. Both resistors R18 and R58 are adjustable resistors to adjust the image brightness and contrast.

[0040] The LCD display driving circuit includes a chip U4, an inductor L3 is connected between pin 1 and pin 6 of the chip U4, a diode D12 is connected between pin 1 and pin 5 of the chip U4, and a grounded capacitor C43 is connected to the connection terminals of the inductor L3 and the diode D12, a capacitor C41 and a capacitor C420 arranged in parallel are connected to pin 5 of the chip U4, and a capacitor C40, a capacitor C39 and a capacitor C38 arranged in parallel are connected to pin 6 of the chip U4;

[0041] A resistor R44 is connected between pin 4 and pin 2 of the chip U4, and a resistor R42 is connected to pin 4 of the chip U4, a resistor R43 is connected to pin 3 of the chip U4, one end of the resistor R43 is connected to a resistor R53, the other end of the resistor R43 is connected to resistors R54 and R55 arranged in parallel, one end of the resistor R54 is respectively connected to a resistor R56 and a capacitor C45, and one end of the resistor R56 is connected to a resistor R45.

[0042] The serial communication circuit includes a chip U21 and a terminal J2, a capacitor C19 is connected between pin 1 and pin 3 of the chip U21, a capacitor C49 is connected between pin 2 and pin 16 of the chip U21, a capacitor C29 is connected between pin 4 and pin 5 of the chip U21, a capacitor C390 is connected between pin 6 and pin 15 of the chip U21, pin 13 of the chip U21 is connected to pin 3 of the terminal J2, and pin 14 of the chip U21 is connected to pin 2 of the terminal J2.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid crystal display light source contrast detection system, characterized in that: It includes a control circuit, a power supply circuit, a light source driving circuit that provides a controllable light source for a liquid crystal display screen, an adaptive light source adjustment circuit that can dynamically adjust the light source according to the actual state of the display screen, an image acquisition circuit that converts analog signals into digital signals, a signal processing circuit that pre-processes the acquired image signals, an image contrast calculation circuit, an LCD display driving circuit that displays contrast detection results, and a serial communication circuit that outputs the detection results; The power supply circuit and the control circuit are both electrically connected to the light source driving circuit, the adaptive light source adjustment circuit, the image acquisition circuit, the signal processing circuit, the image contrast calculation circuit, the LCD display driving circuit and the serial communication circuit, and the power supply circuit is electrically connected to the control circuit.

2. A liquid crystal display light source contrast detection system according to claim 1, characterized in that: The light source driving circuit comprises a chip U1 , a light emitting diode LED1 connected to a power source in a power supply circuit is connected to pin 1 of the chip U1 , and a resistor R1 connected to a ground is connected to pin 5 of the chip U1 .

3. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The adaptive light source adjustment circuit includes a chip U10 and a MOS tube Q1. Resistors R7, R11, R6 and R12 are arranged in parallel between pin 1 and pin 2 of the chip U10. Resistors R10 are connected between a gate G of the MOS tube Q1 and pin 6 of the chip U1. A drain D of the MOS tube Q1 is connected to pin 1 of the chip U1. A diode D4, a diode D2 and a diode D3 arranged in parallel are connected to a source S of the MOS tube Q1.

4. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The image acquisition circuit includes a chip U22, a chip U11 and a terminal J1. A resistor R17 is connected between pin 1 and pin 5 of the chip U22, and a grounded capacitor C5 is connected to pin 5 of the chip U22. A grounded resistor R57 is connected to pin 2 of the chip U22. A capacitor C3 is connected between pin 1 and pin 2 of the chip U11. A capacitor C6 and a capacitor C4 are connected in parallel between pin 1 and pin 3 of the chip U11. A resistor R47 and a resistor R37 connected to a power supply are connected between pin 3 and pin 4 of the terminal J1.

5. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The signal processing circuit includes an amplifier U2A and an amplifier U2B, a capacitor C42 and a resistor R56 are connected between pin 1 of the amplifier U2A and pin 6 of the amplifier U2B, a capacitor C22 which is grounded and connected to a power supply is connected to pin 4 of the amplifier U2A, a resistor R46 and a capacitor C32 are connected in parallel between pins 1 and 2 of the amplifier U2A; a resistor R76 and a capacitor C52 are connected in parallel between pins 6 and 7 of the amplifier U2B.

6. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The image contrast calculation circuit includes a chip U3, an amplifier U3A and an amplifier U3B. Pin 1 of the chip U3 is connected to a resistor R78 and a diode D13 arranged in parallel. Pin 3 of the chip U3 is connected to a capacitor C53. One end of the capacitor C53 is connected to a diode D23 and a resistor R88 arranged in parallel. Resistors R28, R18 and capacitor C13 are connected between pin 2 of the chip U3 and pin 1 of the amplifier U3B. Resistors R38 are connected between pins 1 and 5 of the amplifier U3B. Pin 2 of the amplifier U3B is connected to pins 10 and 6 of the amplifier U3A.

7. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The LCD display driving circuit includes a chip U4, an inductor L3 is connected between pin 1 and pin 6 of the chip U4, a diode D12 is connected between pin 1 and pin 5 of the chip U4, a capacitor C41 and a capacitor C420 arranged in parallel are connected to pin 5 of the chip U4, and a capacitor C40, a capacitor C39 and a capacitor C38 arranged in parallel are connected to pin 6 of the chip U4; A resistor R44 is connected between pin 4 and pin 2 of the chip U4, and a resistor R42 is connected to pin 4 of the chip U4. A resistor R43 is connected to pin 3 of the chip U4. One end of the resistor R43 is connected to a resistor R53, and the other end of the resistor R43 is connected to resistors R54 and R55 arranged in parallel.

8. The liquid crystal display light source contrast detection system according to claim 1, characterized in that: The serial communication circuit includes a chip U21 and a terminal J2, a capacitor C19 is connected between pin 1 and pin 3 of the chip U21, a capacitor C49 is connected between pin 2 and pin 16 of the chip U21, a capacitor C29 is connected between pin 4 and pin 5 of the chip U21, a capacitor C390 is connected between pin 6 and pin 15 of the chip U21, pin 13 of the chip U21 is connected to pin 3 of the terminal J2, and pin 14 of the chip U21 is connected to pin 2 of the terminal J2.

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