Mini / micro led direct display screen response time test method

Abstract

The application discloses a method for testing response time of a mini / micro LED direct display screen, which can avoid the influence of subjective evaluation of human visual perception on the response time, and provides a means for high-precision testing of the response time of the direct display screen through quantitative evaluation method. The method comprises the following steps: (1) a power supply inputs a stable voltage to the direct display screen, the direct display screen is lighted when a square wave driving voltage is input, light enters a microscope lens and converges on a target surface of a high-speed photoelectric detector, a response voltage signal is generated after the target surface is irradiated by the light, the voltage signal is filtered by a high-frequency filter to suppress high-frequency noise, and the voltage signal is connected to an oscilloscope through a BNC line; (2) the power supply is driven and controlled to realize different refresh rates; and step (1) is repeated to realize the response time test of the direct display screen under different refresh rates; and (3) different colors are realized by controlling a signal of the driving power supply; and step (1) is repeated to realize the response time test of the direct display screen under different colors.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of direct screen measurement, and particularly relates to a Mini / Micro LED direct screen response time testing method. BACKGROUND

[0002] Mini LED direct screen is called "sub-millimeter light-emitting diode", which refers to a LED chip with a size of 100-300 mu m, a chip pitch of 0.1-1 mm, and a micro LED device module in the form of SMD, COB or IMD packaging. Mini LED direct screen is mainly applied in the fields of display screen, vehicle display, mobile phone and wearable device. Since 2018, the application end of Pad, vehicle, e-sports and television has shown great interest in Mini LED direct screen, which is used as a substitute for OLED.

[0003] Micro LED direct screen further thins, miniaturizes and arrays the LED structure design, and its size is only in the 1-100 mu m level. As a new generation of display product, Micro LED direct screen will mainly be applied in the existing market of LCD and OLED in the future. At present, Micro LED direct screen is more suitable for indoor large-size display screen and small-size wearable device such as smart watch in the short term, and the application direction of Micro LED direct screen also includes smart phone, tablet, automobile instrument and central control, television and the like.

[0004] Both Mini LED and Micro LED direct screen have the characteristics of high resolution, low power consumption, high contrast, high color saturation, fast response speed, thin thickness and long service life, and the power consumption can be as low as 10% of LCD and 50% of OLED, which is the next generation of display technology expected by the industry. Under the driving of market demand, the production and research and development of Mini / Micro LED direct screen are accelerating.

[0005] The quality factors of Mini / Micro LED direct screen include resolution (pixel number), PPI (pixel density) and response time. The response time reflects the reaction speed of Mini / Micro LED direct screen, that is, the time required for the pixel to turn from dark to bright or from bright to dark. The smaller the response time is, the less the user will feel the tail shadow when watching dynamic pictures.

[0006] Mini / Micro LED direct display screen, whether browsing the web or watching videos, the display content is difficult to achieve only between the conversion of the black and white. Usually display is colorful picture, or the change of the level, which are between the conversion of the gray scale, so the gray scale response time than black and white response time can reflect the actual performance and state of Mini / Micro LED direct display screen. According to the standard of the Ministry of Information Industry, the gray scale response time needs to measure 0, 63, 127, 191, 255, five gray scale levels, a total of 10 groups of response time, and the response time of each group of gray scale is divided into rising time and falling time. In addition, it is also pointed out that the detected brightness signal or relative brightness signal should be filtered when measuring the gray scale response time, in order to suppress high frequency noise. At the same time, the same group of gray scale response time needs to be measured at least 5 times repeatedly to take the average value, in order to reduce the influence of random noise on the response time measurement, and improve the measurement accuracy. The measurement of each group of gray scale response time needs to take 10% of the highest order as the step, from 0% to 100%, to measure the corresponding response time of each gray scale level. The final measurement result of each group of gray scale response time is represented by the maximum value of the response time of each gray scale level.

[0007] With the continuous development and expansion of Mini / Micro LED direct display screen industry, the demand for response time parameter detection of Mini / Micro LED direct display screen is increasing, and the present application is based on the precise measurement of response time of Mini / Micro LED direct display screen, and has a wide application background. SUMMARY

[0008] In order to overcome the defects of the prior art, the technical problem to be solved by the present application is to provide a Mini / Micro LED direct display screen response time testing method, which can avoid the influence of subjective evaluation of human visual perception on response time, and test the response time of Mini / Micro LED direct display screen by quantitative evaluation method, to provide means for high precision testing of Mini / Micro LED direct display screen response time.

[0009] The technical scheme of the present application is that: the Mini / Micro LED direct display screen response time testing method comprises the following steps:

[0010] (1) the power supply inputs sufficient stable voltage for the Mini / Micro LED direct display screen, when the input square wave driving voltage, the Mini / Micro LED direct display screen is lit; the light emitted after lighting enters the microscope lens, and then converges on the target surface of the high-speed photoelectric detector; the high-speed photoelectric detector produces a response voltage signal after being irradiated by the light beam, the voltage signal is filtered by a high-frequency filter to suppress high-frequency noise, and then connected to an oscilloscope through a BNC line;

[0011] (2) Through the driving control of the power supply, different refresh rates of Mini / Micro LED are realized; step (1) is repeated to realize the response time test of Mini / Micro LED direct display screen under different refresh rates;

[0012] (3) By controlling the signal of the driving power supply, Mini / Micro LED displays different colors;

[0013] Step (1) is repeated to realize the response time test of Mini / Micro LED direct display screen under different colors.

[0014] Based on the principle of measuring gray scale response time, the test system is built, through the microscope lens, high-speed detector and high-frequency filter, the response time can be directly observed on the oscilloscope, the principle is simple, has the advantages of fast test and quantification, can measure the response time under different refresh rates and different colors, can analyze the influence of refresh rate and color on response time, can avoid the influence of subjective evaluation of human visual perception on response time, through the quantitative evaluation method to test the response time of Mini / Micro LED direct display screen, provides a means for high-precision test of Mini / Micro LED direct display screen response time, has great significance for the research and development of future large-size display screen and small-size wearable device. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a test device diagram of a Mini / Micro LED direct display screen response time test system disclosed by the application.

[0016] Figure 2 It is a gray scale response time test diagram of a Mini / Micro LED direct display screen disclosed by the application.

[0017] Figure 3 It is a response time test diagram of different refresh rates of a Mini / Micro LED direct display screen disclosed by the application.

[0018] Figure 4 It is a response time test diagram of different wavelength light rays of a Mini / Micro LED direct display screen disclosed by the application.

[0019] Wherein: 1-Mini / Micro LED direct display screen, 2-microscope objective, 3-high-speed photodetector, 4-BNC line, 5-high-frequency filter, 6-oscilloscope, 7-255 gray scale corresponding excitation signal, 8-191 gray scale corresponding excitation signal, 9-127 gray scale corresponding excitation signal, 10-63 gray scale corresponding excitation signal, 11-0 gray scale corresponding excitation signal, 12-255 gray scale corresponding response voltage signal, 13-191 gray scale corresponding response voltage signal, 14-127 gray scale corresponding response voltage signal, 15-63 gray scale corresponding response voltage signal, 16-0 gray scale corresponding response voltage signal, 17-low refresh rate corresponding excitation signal, 18-high refresh rate corresponding excitation signal, 19-low refresh rate corresponding gray scale response voltage signal, 20-high refresh rate corresponding gray scale response voltage signal, 21-Mini / Micro LED direct display screen display red excitation signal, 22-Mini / Micro LED direct display screen display green excitation signal, 23-Mini / Micro LED direct display screen display blue excitation signal, 24-Mini / Micro LED direct display screen presents red gray scale response voltage signal, 25-Mini / Micro LED direct display screen presents green gray scale response voltage signal, 26-Mini / Micro LED direct display screen presents blue gray scale response voltage signal. DETAILED DESCRIPTION

[0020] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the present application.

[0021] It should be noted that the term "comprising" and any variation thereof in the specification and claims of the present application and the above-mentioned drawings is intended to cover the inclusion of not exclusive, for example, the process, method, device, product or equipment including a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0022] As Figure 1 shown, the Mini / Micro LED direct display screen response time test method comprises the following steps:

[0023] (1) The power supply inputs a stable voltage for the Mini / Micro LED direct display screen 1, and when an input square wave driving voltage is input, the Mini / Micro LED direct display screen is lit; the light emitted after being lit enters the microscope lens 2, and then converges on the target surface of the high-speed photodetector 3;

[0024] The high-speed photodetector generates a response voltage signal after being irradiated by a light beam, the voltage signal is inhibited from high-frequency noise through a high-frequency filter 5, and then connected to an oscilloscope 6 through a BNC line 4;

[0025] (2) By driving and controlling the power supply, different refresh rates of the Mini / Micro LED are realized; step (1) is repeated to realize the response time test of the Mini / Micro LED direct display screen under different refresh rates;

[0026] (3) By controlling the signal of the driving power supply, the Mini / Micro LED displays different colors;

[0027] Step (1) is repeated to realize the response time test of the Mini / Micro LED direct display screen under different colors.

[0028] Based on the principle of measuring gray scale response time, the test system is built, through the microscope lens, high-speed detector and high-frequency filter, the response time can be directly observed on the oscilloscope, the principle is simple, has the advantages of fast test and quantification, can measure the response time under different refresh rates and different colors, can analyze the influence of refresh rate and color on the response time, can avoid the influence of subjective evaluation of human visual perception on the response time, and can test the response time of the Mini / Micro LED direct display screen through the quantitative evaluation method, provide a means for high-precision test of the response time of the Mini / Micro LED direct display screen, and has great significance for the research and development of future large-size display screens and small-size wearable devices.

[0029] Preferably, the step (1) comprises the following sub-steps:

[0030] (1.1) For the Mini / Micro LED direct display screen displaying a standard 255-level gray scale module, the gray scale response time measured by 0-level gray scale and 255-level gray scale is black and white response time;

[0031] (1.2) The measurement of the gray scale response time takes 10% of the highest gray scale as a step, from 0% to 100%, measures the response time of the corresponding each group of gray scale level change, and the final measurement result of the gray scale response time is represented by the maximum value in the response time of each group of level change, and the unit is ms;

[0032] (1.3) Measure the response time of the five gray scale levels 0, 63, 127, 191, 255, and measure the response time of adjacent gray scale levels with a step of 10%, then measure a total of 10 groups of gray scale response time, and also measure the rise time and fall time of each group of gray scale response time, so that step (1.3) measures a total of 100 corresponding response voltage signal data;

[0033] (1.4) At least 5 times of repeated measurement for the same group of gray scale response time, and take the average value, so as to reduce the influence of random noise on the response time measurement and improve the measurement accuracy.

[0034] Preferably, in step (1), different microscope lenses are selected according to the size of the Mini / Micro LED direct display screen and the size of the pixel unit, and the parameters considered include: numerical aperture, focal depth, working distance, resolution; different high-speed photoelectric detectors are selected according to the size of the Mini / Micro LED direct display screen and the size of the pixel unit, and the parameters considered include: response wavelength, bandwidth, target surface size.

[0035] Preferably, in step (3), the Mini / Micro LED displays red, green and blue colors (including but not limited to red, green and blue colors) by controlling the signal of the driving power supply.

[0036] The application will be described in more detail below with reference to the accompanying drawings.

[0037] Figure 1 A Mini / Micro LED direct display screen response time measurement test device disclosed by the application is shown in the figure, which comprises a Mini / Micro LED direct display screen 1, a microscopic objective lens 2, a high-speed photoelectric detector 3, a BNC line 4, a high-frequency filter 5, and an oscilloscope 6. The Mini / Micro LED direct display screen 1 is provided with a sufficient stable power supply by a PG power supply. When a square wave driving voltage is input to the Mini / Micro LED direct display screen 1, the Mini / Micro LED direct display screen 1 is lit, the microscopic objective lens 2 collects a light beam and focuses it on the target surface of the high-speed photoelectric detector 3. The high-speed photoelectric detector 3 generates a response voltage signal after being irradiated by the light beam, and connects the signal to the high-frequency filter 5 through the BNC line 4 for filtering processing. The filtered signal enters the input end of the oscilloscope 6, and the response time of the Mini / Micro LED direct display screen 1 is obtained through the time measurement function of the oscilloscope 6. In order to study the influence of the refresh rate and color of the Mini / Micro LED direct display screen 1 on the response time, the frequency of the input square wave can be adjusted to change the wavelength of the light beam emitted by the Mini / Micro LED direct display screen 1.

[0038] By driving control on the power supply, the Mini / Micro LED has different refresh rates and different light colors. By using the response time test system of the Mini / Micro LED direct display screen disclosed by the application, the response time of the Mini / Micro LED direct display screen under different refresh rates and different colors can be researched, the influence of the refresh rate and color of the Mini / Micro LED direct display screen on the response time is researched, and technical guidance is provided for the measurement of the response time.

[0039] As Figure 2 The gray scale response time test diagram of the Mini / Micro LED direct display screen disclosed by the application is shown, which includes 255 gray scale corresponding excitation signal 7, 191 gray scale corresponding excitation signal 8, 127 gray scale corresponding excitation signal 9, 63 gray scale corresponding excitation signal 10, 0 gray scale corresponding excitation signal 11, 255 gray scale corresponding response voltage signal 12, 191 gray scale corresponding response voltage signal 13, 127 gray scale corresponding response voltage signal 14, 63 gray scale corresponding response voltage signal 15, and 0 gray scale corresponding response voltage signal 16. Wherein 0 gray scale represents black, 255 gray scale represents white, and the intermediate color is the transition color from black to white. By Figure 1 The test system is built, according to the experimental step 1, the voltage signal of the response time of different gray scales is obtained, and then the gray scale response time is calculated.

[0040] Figure 3 The response time test diagram of the Mini / Micro LED direct display screen disclosed by the application is shown, which includes low refresh rate corresponding excitation signal 17, high refresh rate corresponding excitation signal 18, low refresh rate corresponding gray scale response voltage signal 19, and high refresh rate corresponding gray scale response voltage signal 20. By driving control on the power supply, the Mini / Micro LED has different refresh rates, according to the description of step 2, the response time of the Mini / Micro LED direct display screen under different refresh rates can be measured.

[0041] Figure 4A Mini / Micro LED direct display screen different wavelength light corresponding response time test chart disclosed by the application, including a Mini / Micro LED direct display screen display red excitation signal 21, a Mini / Micro LED direct display screen display green excitation signal 22, a Mini / Micro LED direct display screen display blue excitation signal 23, a Mini / Micro LED direct display screen present red gray scale response voltage signal 24, a Mini / Micro LED direct display screen present green gray scale response voltage signal 25, and a Mini / Micro LED direct display screen present blue gray scale response voltage signal 26. By controlling the signal of the driving power supply, the Mini / Micro LED direct display screen presents red, green and blue respectively, and according to the operation of step 3, the corresponding gray scale response time of the three is measured respectively.

[0042] In summary, compared with measuring the black and white response time of the Mini / Micro LED direct display screen, the application has more extensive practicability in measuring the gray scale response time of the Mini / Micro LED direct display screen, and can better meet the research and development requirements of the Mini / Micro LED direct display screen in the future in large-size display screens and small-size wearable devices. In addition, based on the characteristics of high resolution, low power consumption, high contrast, high color saturation, fast response speed, thin thickness, long service life and the like of the Mini / Micro LED direct display screen, it is crucial to measure the parameters of the Mini / Micro LED direct display screen. The response time device for testing the Mini / Micro LED direct display screen designed by the application also has the advantages of simple structure, low cost, fast response speed and apparent directness.

[0043] The above is only a preferred embodiment of the application, and does not limit the application in any form. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the application still belongs to the protection scope of the technical solution of the application.

Claims

1.A method for testing response time of a Mini / Micro LED direct display screen, characterized in that: It comprises the following steps: (1) The power supply inputs a stable voltage to the Mini / Micro LED direct display screen (1), and the Mini / Micro LED direct display screen is lit when the input square wave driving voltage is input; the light emitted after being lit enters the microscope lens (2), and then converges on the target surface of the high-speed photoelectric detector (3); the high-speed photoelectric detector generates a response voltage signal after being irradiated by the light beam, the voltage signal is inhibited by the high-frequency filter (5) to suppress high-frequency noise, and then connected to the oscilloscope (6) through the BNC line (4); (2) The different refresh rates of the Mini / Micro LED are realized by driving control of the power supply; the step (1) is repeated to realize the response time test of the Mini / Micro LED direct display screen under different refresh rates; (3) The Mini / Micro LED displays different colors by controlling the signal of the driving power supply; the step (1) is repeated to realize the response time test of the Mini / Micro LED direct display screen under different colors; The step (1) comprises the following sub-steps: (1.1) For the Mini / Micro LED direct display screen displaying the standard 255 gray scale module, the gray scale response time measured by 0 gray scale and 255 gray scale is the black and white response time; (1.2) The measurement of the gray scale response time takes 10% of the highest gray scale as a step, from 0% to 100%, and measures the response time of the corresponding gray scale change in each group, and the final measurement result of the gray scale response time is represented by the maximum value in the response time of the gray scale change in each group, and the unit is ms; (1.3) The response time of 0, 63, 127, 191, 255 gray scales is measured, and the response time of adjacent gray scales is measured with 10% as a step, so that 10 groups of gray scale response time are measured, and the rise time and fall time of each group of gray scale response time are also measured, so that step (1.3) measures 100 corresponding response voltage signal data in total; (1.4) For the same group of gray scale response time, at least 5 repeated measurements are taken, and the average value is taken, so as to reduce the influence of random noise on the response time measurement and improve the measurement accuracy. 2.The Mini / Micro LED direct display screen response time test method according to claim 1, characterized in that: In the step (1), according to the size of the Mini / Micro LED direct display screen and the size of the pixel unit, different microscope lenses are selected, and the parameters considered include: numerical aperture, focal depth, working distance, resolution; according to the size of the Mini / Micro LED direct display screen and the size of the pixel unit, different high-speed photoelectric detectors are selected, and the parameters considered include: response wavelength, bandwidth, target surface size. 3.The Mini / Micro LED direct display screen response time test method according to claim 2, characterized in that: In the step (3), the Mini / Micro LED displays red, green and blue three colors by controlling the signal of the driving power supply.

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