A method and system for testing transmission signals of a liquid crystal display product

Abstract

The application relates to the technical field of signal quality testing, and discloses a transmission signal testing method and system for a liquid crystal display product, the method comprising the following steps: collecting a PWM analog signal and a TE digital signal of a liquid crystal display product to be tested; performing analog-digital conversion on the PWM analog signal; performing edge capture on the TE digital signal; obtaining PWM discrete timing data and TE edge timestamp data; performing fast Fourier transform (FFT) analysis on the discrete timing data to obtain PWM signal characteristic data; calculating the frequency of the TE signal based on the TE edge timestamp data; statistically analyzing the period discrete degree to obtain TE signal characteristic data; comparing the two types of characteristic data with preset quality thresholds; generating a test determination result for the liquid crystal display product to be tested; and generating a test determination report based on the test determination result. The application can improve the efficiency of transmission signal testing of a liquid crystal display product.

Description

Technical Field

[0001] This invention relates to the field of signal quality testing technology, and in particular to a method and system for testing the transmission signals of liquid crystal display products. Background Technology

[0002] In the field of transmission signal testing for LCD products, existing technologies for evaluating the quality of PWM signals are relatively simple, generally relying on counters or timers. By measuring the signal frequency, it is determined whether the frequency is within the preset target frequency tolerance range. This testing method can only preliminarily verify the frequency compliance of the PWM signal, completely ignoring the impact of signal waveform purity on the display effect. It cannot detect problems such as harmonic distortion in the signal, resulting in a large number of display quality defects caused by PWM signal waveform distortion not being detected in time, which seriously affects the effectiveness of product quality control.

[0003] Existing technologies for testing TE synchronization signals also have significant limitations. Their core remains focused on frequency measurement, calculating the TE signal frequency to verify whether it matches the expected display frame rate. However, the periodic stability of the TE signal directly affects the synchronization accuracy of the displayed image. Existing testing methods do not analyze the dispersion of multiple consecutive TE pulse cycles, making it impossible to quantify key indicators such as period jitter. This makes it difficult to accurately identify problems such as screen stuttering and tearing caused by unstable TE signal timing. The aforementioned deficiencies in the testing dimensions of existing technologies result in test results that cannot fully reflect the true quality of the transmitted signal, failing to meet the stringent testing requirements of high-definition LCD products and restricting the accuracy and reliability of product testing. Therefore, improving the accuracy and reliability of product testing has become an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a method and system for testing the transmission signals of liquid crystal display products, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a method for testing the transmission signal of a liquid crystal display product, comprising:

[0006] S1, acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and perform edge capture on the TE digital signal to obtain TE edge timestamp data;

[0007] S2, perform Fast Fourier Transform (FFT) analysis on the PWM discrete timing data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data;

[0008] S3, calculate the frequency of the TE signal based on the TE edge timestamp data, and statistically analyze the period dispersion to obtain the characteristic data of the TE signal;

[0009] S4, compare the PWM signal feature data and the TE signal feature data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test;

[0010] S5, A test judgment report is generated based on the test judgment results.

[0011] In a preferred embodiment, the step of performing analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data includes:

[0012] Based on the highest frequency of the PWM analog signal, the sampling rate of the ADC is set to 10 times the highest frequency for continuous sampling to obtain the original sampled voltage sequence.

[0013] The original sampled voltage sequence is subjected to data format standardization processing to obtain PWM discrete timing data.

[0014] In a preferred embodiment, the step of capturing the edge of the TE digital signal to obtain TE edge timestamp data includes:

[0015] Based on the edge type of the TE digital signal to be measured, the capture parameters of the input capture unit are configured, and the current count value of the timer is captured and read to obtain the original capture count value.

[0016] Based on the original capture count value and the timer clock frequency, the timestamp is calculated using the timestamp conversion formula to obtain the absolute timestamp;

[0017] Based on multiple consecutive absolute timestamps, an ordered timestamp sequence is constructed to obtain TE edge timestamp data.

[0018] In a preferred embodiment, the step of performing Fast Fourier Transform (FFT) analysis on the PWM discrete-time data to extract preset frequency domain features from the obtained spectrum to obtain PWM signal feature data includes:

[0019] The PWM discrete timing data is windowed to obtain windowed time-domain data.

[0020] Based on the Fast Fourier Transform (FFT) algorithm, the windowed time-domain data is transformed in the frequency domain to obtain PWM spectrum data.

[0021] Based on the amplitude spectrum of the PWM spectrum data, the fundamental frequency and fundamental amplitude are extracted, and the amplitude value corresponding to the third harmonic frequency is located in the amplitude spectrum to obtain the third harmonic amplitude.

[0022] Based on the fundamental frequency amplitude and the third harmonic amplitude, the distortion is calculated using the total harmonic distortion calculation formula to obtain the total harmonic distortion (THD) value.

[0023] The fundamental frequency, the fundamental amplitude, the third harmonic amplitude, and the total harmonic distortion (THD) value are combined to obtain PWM signal characteristic data.

[0024] In a preferred embodiment, the mathematical expression of the Fast Fourier Transform (FFT) algorithm is as follows:

[0025] ;

[0026] In the formula, X[k] represents the PWM spectrum data, x[n] represents the nth sampling point in the PWM discrete timing data, w[n] represents the window function value, N is the total number of points participating in the FFT operation, and j is the imaginary unit. is the rotation factor, and n is the index of the sampling point.

[0027] In a preferred embodiment, the step of calculating the frequency of the TE signal based on the TE edge timestamp data and statistically analyzing the period dispersion to obtain TE signal characteristic data includes:

[0028] Based on the TE edge timestamp data, the time difference between adjacent edge timestamps is calculated to obtain the TE period data;

[0029] Calculate the average and reciprocal of the TE periodic data to obtain the TE signal frequency;

[0030] Based on the TE cycle data, the average value of all cycles is calculated to obtain the average cycle.

[0031] Based on the TE period data and the average period, the period jitter value is obtained by statistical calculation using the period jitter calculation formula.

[0032] The TE signal frequency and the period jitter value are combined to obtain TE signal characteristic data.

[0033] In a preferred embodiment, the mathematical expression for the period jitter calculation formula is as follows:

[0034] ;

[0035] In the formula, J te T represents the periodic jitter value. iIt is the value of the i-th TE cycle, T avg It is the average of all TE period values, m is the number of TE edge timestamps, so (m-1) is the number of period values ​​Ti, and (m-2) is the degree of freedom when calculating the sample standard deviation, and i is the timestamp index.

[0036] In a preferred embodiment, the step of comparing the PWM signal characteristic data and the TE signal characteristic data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test includes:

[0037] Based on preset quality assessment rules, the PWM signal feature data and the TE signal feature data are compared one by one to obtain the comparison status of each feature data.

[0038] A comprehensive logical judgment is made on the comparison status to obtain an overall judgment conclusion;

[0039] Based on the overall judgment conclusion and the feature data that failed the comparison, a test judgment result containing diagnostic information is generated.

[0040] In a preferred embodiment, the test judgment report generated based on the test judgment result includes:

[0041] Based on the test results and diagnostic information, the results are output in real time through a preset output interface to generate display information that can be perceived by the operator.

[0042] Based on the test results, raw data, process data, and associated metadata, the data is packaged and formatted to generate a test report.

[0043] To address the above problems, the present invention also provides a transmission signal testing system for liquid crystal display products, the system comprising:

[0044] The signal acquisition and digitization module is used to acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, and to perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and to perform edge capture on the TE digital signal to obtain TE edge timestamp data.

[0045] The PWM signal frequency domain feature extraction module is used to perform Fast Fourier Transform (FFT) analysis on the PWM discrete time series data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data.

[0046] The TE signal time-domain feature extraction module is used to calculate the frequency of the TE signal based on the TE edge timestamp data, and to statistically analyze the period dispersion to obtain TE signal feature data.

[0047] The comprehensive quality assessment and judgment module is used to compare the PWM signal characteristic data and the TE signal characteristic data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test.

[0048] The test result output module is used to generate a test judgment report based on the test judgment results.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. This invention significantly improves the comprehensiveness and accuracy of signal quality assessment by introducing a "frequency domain waveform purity" analysis dimension into PWM signal testing. Existing technologies only measure the PWM signal frequency using counters or timers, which can only determine whether the frequency is within the target tolerance range and cannot detect potential problems such as signal waveform distortion. This invention, for the first time, systematically applies Fast Fourier Transform analysis in a production line testing scenario. Through standardized processes such as windowing and frequency domain transformation, it accurately extracts core spectral features such as fundamental frequency, fundamental amplitude, third harmonic amplitude, and total harmonic distortion. These indicators can comprehensively quantify the waveform purity of the signal and effectively identify harmonic interference and distortion problems caused by factors such as circuit nonlinearity. It fills the technical gap in existing testing at the frequency domain level, making the test results more consistent with the actual display effect requirements of LCD products and providing more reliable technical support for product quality control.

[0051] 2. This invention adds a time-domain periodic stability analysis dimension, significantly improving the depth and practicality of synchronization signal quality assessment. Existing technologies only measure the TE signal frequency to verify whether it matches the expected display frame rate, ignoring the impact of periodic dispersion on synchronization accuracy. This invention not only accurately calculates the average frequency of the TE signal, but also obtains high-precision timestamp data through edge capture, derives the periodic data of multiple consecutive TE pulses, and then uses a professional periodic jitter calculation formula to statistically analyze the periodic dispersion. The obtained periodic jitter value can intuitively reflect the timing stability of the signal. This innovative design can accurately identify potential problems such as screen stuttering and tearing caused by timing fluctuations. At the same time, combined with preset quality thresholds, it forms a judgment result containing diagnostic information, providing a clear basis for product qualification and precise guidance for subsequent fault diagnosis and process optimization, significantly improving the engineering application value of testing and the product reliability assurance capability. Attached Figure Description

[0052] Figure 1 This is a flowchart illustrating a method for testing the transmission signal of a liquid crystal display product according to an embodiment of the present invention.

[0053] Figure 2 A functional block diagram of a transmission signal testing system for a liquid crystal display product provided in an embodiment of the present invention;

[0054] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0055] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0056] This application provides a method for testing the transmission signal of a liquid crystal display product. The execution subject of this method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the method for testing the transmission signal of a liquid crystal display product can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDN), and big data and artificial intelligence platforms.

[0057] Reference Figure 1 The diagram shown is a flowchart illustrating a method for testing the transmission signal of a liquid crystal display product according to an embodiment of the present invention. In this embodiment, the method for testing the transmission signal of a liquid crystal display product includes:

[0058] S1, acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and perform edge capture on the TE digital signal to obtain TE edge timestamp data;

[0059] In this embodiment of the invention, the step of performing analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data includes:

[0060] Based on the highest frequency of the PWM analog signal, the sampling rate of the ADC is set to 10 times the highest frequency for continuous sampling to obtain the original sampled voltage sequence.

[0061] The original sampled voltage sequence is subjected to data format standardization processing to obtain PWM discrete timing data.

[0062] It should be noted that the original sampled voltage sequence refers to a series of discrete digital voltage values ​​arranged in chronological order. It is the direct result of the ADC discretizing the continuous-time PWM waveform and fully records the voltage magnitude of the PWM signal at all sampling points within an observation period.

[0063] It should be noted that data format standardization processing means converting each digital voltage value in the original sampled voltage sequence into a unified engineering unit representation based on the ADC's reference voltage and resolution, and organizing it according to the timing index to ultimately generate structured PWM discrete timing data.

[0064] It should be noted that PWM discrete timing data is a time-domain discrete sequence, which is the digital representation of the PWM analog signal after sampling and amplitude quantization at equal time intervals. The nth data point x[n] in the sequence corresponds to the sampling time t=n / F. s The voltage amplitude of the PWM signal is the basis for subsequent frequency domain analysis such as Fast Fourier Transform. Its accuracy and completeness directly determine the effectiveness of feature extraction and final quality assessment. Here, x[n] represents the discrete-time data of the PWM signal, and F... s The sampling frequency.

[0065] In this embodiment of the invention, the step of obtaining TE edge timestamp data by edge capture of the TE digital signal includes:

[0066] Based on the edge type of the TE digital signal to be measured, the capture parameters of the input capture unit are configured, and the current count value of the timer is captured and read to obtain the original capture count value.

[0067] Based on the original capture count value and the timer clock frequency, the timestamp is calculated using the timestamp conversion formula to obtain the absolute timestamp;

[0068] Based on multiple consecutive absolute timestamps, an ordered timestamp sequence is constructed to obtain TE edge timestamp data.

[0069] It should be noted that configuring the capture parameters refers to setting the input capture unit to respond to a specified level transition type of the TE digital signal. The edge types to be measured include rising edge and falling edge. This configuration determines the triggering condition of the capture action, ensuring that the effective TE signal transition moment can be accurately captured.

[0070] Furthermore, the timer's operating mode is configured to free-running mode, in which the timer count value starts from zero and increases continuously and cyclically according to its internal clock frequency. This method provides a continuously and linearly increasing time base, and the timer's current count value is momentarily latched when a specified type of edge event occurs on the TE signal.

[0071] It should be noted that the raw capture count value is the count value latched by the timer at the moment the TE signal edge event is triggered. This value is an integer proportional to the number of timer clock cycles and represents the reference number of clock cycles that have elapsed from timer start to edge event occurrence. It is the basic raw data for calculating precise absolute time.

[0072] It should be noted that the timestamp conversion formula is implemented as follows: the captured original count value is divided by the clock frequency of the timer to obtain the absolute timestamp in seconds. This calculation converts the hardware count value into physical time, which is the direct input for subsequent calculations of signal period and frequency.

[0073] It should be noted that an absolute timestamp is a physical time value in seconds. It accurately records the absolute moment when the i-th TE signal edge event occurs. It is the precise location of the signal event on the time axis and the most direct basis for analyzing the timing characteristics of the signal.

[0074] It should be noted that TE edge timestamp data is an ordered sequence consisting of multiple consecutive absolute timestamps arranged in chronological order. This data fully records the precise occurrence time of all captured TE signal edge events within the observation window, and is essentially a set of digitized time coordinates of key transition points in the time-domain waveform of the TE signal.

[0075] S2, perform Fast Fourier Transform (FFT) analysis on the PWM discrete timing data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data;

[0076] In this embodiment of the invention, the step of performing Fast Fourier Transform (FFT) analysis on the PWM discrete-time data to extract preset frequency domain features from the obtained spectrum to obtain PWM signal feature data includes:

[0077] The PWM discrete timing data is windowed to obtain windowed time-domain data.

[0078] Based on the Fast Fourier Transform (FFT) algorithm, the windowed time-domain data is transformed in the frequency domain to obtain PWM spectrum data.

[0079] Based on the amplitude spectrum of the PWM spectrum data, the fundamental frequency and fundamental amplitude are extracted, and the amplitude value corresponding to the third harmonic frequency is located in the amplitude spectrum to obtain the third harmonic amplitude.

[0080] Based on the fundamental frequency amplitude and the third harmonic amplitude, the distortion is calculated using the total harmonic distortion calculation formula to obtain the total harmonic distortion (THD) value.

[0081] The fundamental frequency, the fundamental amplitude, the third harmonic amplitude, and the total harmonic distortion (THD) value are combined to obtain PWM signal characteristic data.

[0082] It should be noted that windowing refers to multiplying the PWM discrete timing data point by point with a preset window function. The window function gradually decays to zero at the beginning and end of the data segment to reduce the spectral leakage caused by the truncation of the time domain signal, so that the spectrum obtained by subsequent FFT analysis can more accurately reflect the frequency components of the original signal.

[0083] Furthermore, the window function used is the Hanning window, whose mathematical expression is as follows:

[0084]

[0085] In the formula, w[n] is the time-domain data after windowing, N is the length of the window, that is, the number of PWM discrete-time data points participating in the windowing process, and n is the sampling point index.

[0086] It should be noted that the windowed time-domain data is the result of the original PWM discrete timing data being weighted by a window function. This is achieved by suppressing abrupt changes at the boundaries of the data segments, making the boundaries of the data segments smoother during periodic extension, thus laying the foundation for obtaining a clearer spectrum in the future.

[0087] It should be noted that extracting the fundamental frequency and fundamental amplitude means finding the frequency point with the largest amplitude value among all frequency points in the amplitude spectrum. The frequency corresponding to this frequency point is the fundamental frequency of the signal, and its corresponding amplitude value is the fundamental amplitude. This operation locates the most important frequency components in the signal.

[0088] It should be noted that the third harmonic amplitude A 3rd This refers to finding a frequency point k in the amplitude spectrum that is approximately three times the fundamental frequency. 3rd The amplitude value corresponding to this frequency point is |X[k] 3rd This refers to the third harmonic amplitude, which is an important nonlinear distortion index in signal distortion analysis.

[0089] It should be noted that the mathematical expression for the total harmonic distortion calculation formula is as follows:

[0090]

[0091] In the formula, THD pwm A represents the total harmonic distortion (THD) value. base It is the fundamental amplitude, A h It is the amplitude of the h-th harmonic, M is the upper limit of the harmonic order considered, and h is the harmonic amplitude index.

[0092] It should be noted that the Total Harmonic Distortion (THD) value is a dimensionless percentage used to quantify the severity of distortion in a PWM signal. It is the square root of the ratio of the total power of harmonic components introduced by nonlinear distortion to the fundamental power. The larger the THD value, the more severely the signal waveform deviates from the ideal sine wave or square wave, and the worse the signal quality.

[0093] It should be noted that the PWM signal characteristic data is a set of data including fundamental frequency, fundamental amplitude, third harmonic amplitude and total harmonic distortion. This data fully characterizes the key quality attributes of the PWM signal from the frequency domain perspective: dominant frequency, intensity, specific harmonic components and overall distortion.

[0094] In this embodiment of the invention, the mathematical expression of the Fast Fourier Transform (FFT) algorithm is as follows:

[0095] ;

[0096] In the formula, X[k] represents the PWM spectrum data, x[n] represents the nth sampling point in the PWM discrete timing data, w[n] represents the window function value, N is the total number of points participating in the FFT operation, and j is the imaginary unit. is the rotation factor, and n is the sampling point index.

[0097] It should be noted that PWM spectrum data is a complex sequence, which is the complete representation of the PWM signal in the frequency domain. Its amplitude spectrum |X[k]|, that is, the modulus of each X[k], represents the frequency component f. k =k*F s By analyzing the amplitude spectrum of a sinusoidal wave of / N, the fundamental and harmonic components and their energy distribution within the signal can be identified. Among these, F... s Where N is the sampling rate, and N is the total number of points involved in the FFT operation.

[0098] S3, calculate the frequency of the TE signal based on the TE edge timestamp data, and statistically analyze the period dispersion to obtain the characteristic data of the TE signal;

[0099] In this embodiment of the invention, the step of calculating the frequency of the TE signal based on the TE edge timestamp data and statistically analyzing the period dispersion to obtain TE signal characteristic data includes:

[0100] Based on the TE edge timestamp data, the time difference between adjacent edge timestamps is calculated to obtain the TE period data;

[0101] Calculate the average and reciprocal of the TE periodic data to obtain the TE signal frequency;

[0102] Based on the TE cycle data, the average value of all cycles is calculated to obtain the average cycle.

[0103] Based on the TE period data and the average period, the period jitter value is obtained by statistical calculation using the period jitter calculation formula.

[0104] The TE signal frequency and the period jitter value are combined to obtain TE signal characteristic data.

[0105] It should be noted that the calculation of the average and reciprocal of the TE periodic data involves: first, calculating the arithmetic mean of the TE periodic data sequence, which represents the average period length of the signal within the observation period; then, calculating the reciprocal of this average period, which converts the average period in the time dimension into the average rate in the frequency dimension.

[0106] It should be noted that the TE signal frequency is a physical quantity in units, representing the number of periodic events that occur in the TE signal per unit time.

[0107] It should be noted that calculating the average of all periods means summing all elements in the TE periodic data sequence and then dividing by the total number of elements to obtain the arithmetic mean. This average period is the benchmark reference value for subsequent calculation of period jitter.

[0108] It should be noted that the TE signal characteristic data is a dataset containing the frequency and period jitter values ​​of the TE signal. This data fully characterizes the key quality attributes of the TE signal from a time domain perspective: average rate and timing stability. Its role is to serve as the core quantitative basis for comparing with preset quality thresholds and objectively evaluating the synchronization quality and stability of the TE signal.

[0109] In this embodiment of the invention, the mathematical expression of the period jitter calculation formula is as follows:

[0110] ;

[0111] In the formula, J te T represents the periodic jitter value. i It is the value of the i-th TE cycle, T avg It is the average of all TE period values, m is the number of TE edge timestamps, so (m-1) is the number of period values ​​Ti, and (m-2) is the degree of freedom when calculating the sample standard deviation, and i is the timestamp index.

[0112] It should be noted that the period jitter value is a statistical quantity in units of time. It is a quantitative indicator of the dispersion of each period value of the TE signal relative to its average period. The larger the value, the greater the fluctuation of the actual length of each period, the worse the timing accuracy of the signal, and the weaker the synchronization stability. The smaller the value, the more stable the period and the more accurate the signal timing.

[0113] S4, compare the PWM signal feature data and the TE signal feature data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test;

[0114] In this embodiment of the invention, the step of comparing the PWM signal feature data and the TE signal feature data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test includes:

[0115] Based on preset quality assessment rules, the PWM signal feature data and the TE signal feature data are compared one by one to obtain the comparison status of each feature data.

[0116] A comprehensive logical judgment is made on the comparison status to obtain an overall judgment conclusion;

[0117] Based on the overall judgment conclusion and the feature data that failed the comparison, a test judgment result containing diagnostic information is generated.

[0118] It should be noted that the preset quality assessment rules are comprehensively set based on the specifications of the LCD product under test, industry standards, and historical good product data statistics. These rules define clear acceptable tolerance ranges for each key characteristic data point of the PWM and TE signals, and set a target range for the PWM fundamental frequency [FR]. target -ΔF1, FR target +ΔF1]; sets the upper limit threshold for total harmonic distortion; sets the target range for TE signal frequency [FR]. target -ΔF2, FR target +ΔF2]; sets an upper limit threshold for the periodic jitter value, where FR target The target frame rate for the LCD display.

[0119] Furthermore, the default value of ΔF1 is FR. target ×0.05, ΔF2 is set to 0.5 by default, ΔF1 can be set according to the product specification, for example, 5% or 10%, and ΔF2 can be set according to the product's tolerance for timing jitter, for example, 1% to 2% of the average period.

[0120] It should be noted that performing a one-by-one comparison means comparing each item in the PWM signal characteristic data and TE signal characteristic data with the corresponding threshold or range in the preset quality assessment rules. This comparison process generates a series of Boolean comparison states, such as "fundamental frequency is within the target range" (True / False), "total harmonic distortion is less than the upper limit" (True / False), "period jitter is less than the tolerance" (True / False), etc.

[0121] It should be noted that the comparison status of each feature data is a binary identifier indicating whether each quantified feature meets the preset quality requirements. Its physical meaning is to make a preliminary judgment on the pass / fail status of individual signal indicators, and it is a fundamental element constituting the final comprehensive judgment.

[0122] It should be noted that comprehensive logical judgment refers to performing a logical AND operation on the comparison status of all feature data. That is, the overall judgment is qualified only when the comparison status of all features is passed. If the comparison status of any one or more features is failed, the overall judgment is unqualified.

[0123] It should be noted that the overall judgment is a binary conclusion, indicating whether the PWM and TE signal quality of the LCD product under test meets the preset standards in this test. It is the final and comprehensive quality judgment on the product's signal output performance.

[0124] It should be noted that generating test judgment results containing diagnostic information means adding specific diagnostic information to the overall conclusion of passing or failing. When the overall judgment is failing, the diagnostic information must clearly indicate which characteristic data failed the comparison, and can include specific measured values ​​and thresholds, such as excessive TE cycle jitter or excessive PWM total harmonic distortion. When the overall judgment is passing, the diagnostic information can be simplified to all indicators being within the tolerance range. The role of this diagnostic information is to provide direct and clear clues and basis for subsequent engineering analysis, problem localization, and process improvement.

[0125] It should be noted that the test result is a structured data object that contains overall quality conclusions and detailed diagnostic information. It is the final output of this test. It is not only a label for whether the product is qualified or unqualified, but also a key information carrier connecting the testing process with subsequent quality improvement links, which greatly improves the diagnostic efficiency and engineering value of the test.

[0126] S5, A test judgment report is generated based on the test judgment results.

[0127] In this embodiment of the invention, the test judgment report generated based on the test judgment result includes:

[0128] Based on the test results and diagnostic information, the results are output in real time through a preset output interface to generate display information that can be perceived by the operator.

[0129] Based on the test results, raw data, process data, and associated metadata, the data is packaged and formatted to generate a test report.

[0130] It should be noted that real-time result output refers to presenting the test results and their accompanying diagnostic information in the form of text, graphics, or audio-visual signals in real time through a hardware communication interface or by directly driving a local display device. This is to ensure the immediate visualization and interactivity of the test conclusions, so that on-site operators can know the product quality status at the first moment.

[0131] It should be noted that the raw data includes PWM discrete timing data and TE edge timestamp data; the process data includes PWM signal characteristic data and TE signal characteristic data and the intermediate TE cycle data; the associated metadata includes test timestamp, product under test serial number, test station number, and key configuration parameters used, such as ADC sampling rate, FFT points, quality threshold, etc.

[0132] It should be noted that data packaging and formatting refers to integrating, encapsulating, and serializing the test results, raw data, process data, and metadata according to predefined data structures and encoding rules. The purpose of this process is to integrate all the heterogeneous and scattered data items generated in a test into a logically unified, formatted, and machine-readable complete data package.

[0133] It should be noted that the test judgment report is a data entity that fully encapsulates the entire lifecycle information of a single test. It is a complete "archive" or "snapshot" of this test in the digital space. From the original evidence and analysis process to the final conclusion, it retains a complete and traceable data chain, providing an immutable data foundation for subsequent statistical analysis, root cause tracing, and production quality improvement.

[0134] like Figure 2 The diagram shown is a functional block diagram of a transmission signal testing system for a liquid crystal display product according to an embodiment of the present invention.

[0135] The transmission signal testing system 100 for liquid crystal display products described in this invention can be installed in electronic devices. Depending on the functions implemented, the transmission signal testing system 100 for liquid crystal display products may include a signal acquisition and digitization module 101, a PWM signal frequency domain feature extraction module 102, a TE signal time domain feature extraction module 103, a comprehensive quality assessment and judgment module 104, and a test result output module 105. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and is stored in the memory of the electronic device.

[0136] In this embodiment, the functions of each module / unit are as follows:

[0137] The signal acquisition and digitization module is used to acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, and to perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and to perform edge capture on the TE digital signal to obtain TE edge timestamp data.

[0138] The PWM signal frequency domain feature extraction module is used to perform Fast Fourier Transform (FFT) analysis on the PWM discrete time series data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data.

[0139] The TE signal time-domain feature extraction module is used to calculate the frequency of the TE signal based on the TE edge timestamp data, and to statistically analyze the period dispersion to obtain TE signal feature data.

[0140] The comprehensive quality assessment and judgment module is used to compare the PWM signal feature data and the TE signal feature data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test.

[0141] The test result output module is used to generate a test judgment report based on the test judgment results.

[0142] In the several embodiments provided by this invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0143] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0144] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0145] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0146] The embodiments of this application can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence is the theory, method, technology, and application system that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for testing the transmission signal of a liquid crystal display product, characterized in that, The method includes: S1, acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and perform edge capture on the TE digital signal to obtain TE edge timestamp data; S2, perform Fast Fourier Transform (FFT) analysis on the PWM discrete timing data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data; S3, calculate the frequency of the TE signal based on the TE edge timestamp data, and statistically analyze the period dispersion to obtain the characteristic data of the TE signal; S4, compare the PWM signal feature data and the TE signal feature data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test; S5, A test judgment report is generated based on the test judgment results.

2. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The step of performing analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data includes: Based on the highest frequency of the PWM analog signal, the sampling rate of the ADC is set to 10 times the highest frequency for continuous sampling to obtain the original sampled voltage sequence. The original sampled voltage sequence is subjected to data format standardization processing to obtain PWM discrete timing data.

3. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The step of capturing the edge of the TE digital signal to obtain TE edge timestamp data includes: Based on the edge type of the TE digital signal to be measured, the capture parameters of the input capture unit are configured, and the current count value of the timer is captured and read to obtain the original capture count value. Based on the original capture count value and the timer clock frequency, the timestamp is calculated using the timestamp conversion formula to obtain the absolute timestamp; Based on multiple consecutive absolute timestamps, an ordered timestamp sequence is constructed to obtain TE edge timestamp data.

4. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The step of performing Fast Fourier Transform (FFT) analysis on the PWM discrete-time data, extracting preset frequency domain features from the obtained spectrum, and obtaining PWM signal feature data includes: The PWM discrete timing data is windowed to obtain windowed time-domain data. Based on the Fast Fourier Transform (FFT) algorithm, the windowed time-domain data is transformed in the frequency domain to obtain PWM spectrum data. Based on the amplitude spectrum of the PWM spectrum data, the fundamental frequency and fundamental amplitude are extracted, and the amplitude value corresponding to the third harmonic frequency is located in the amplitude spectrum to obtain the third harmonic amplitude. Based on the fundamental frequency amplitude and the third harmonic amplitude, the distortion is calculated using the total harmonic distortion calculation formula to obtain the total harmonic distortion (THD) value. The fundamental frequency, the fundamental amplitude, the third harmonic amplitude, and the total harmonic distortion (THD) value are combined to obtain PWM signal characteristic data.

5. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The mathematical expression for the Fast Fourier Transform (FFT) algorithm is as follows: ; In the formula, X[k] represents the PWM spectrum data, x[n] represents the nth sampling point in the PWM discrete timing data, w[n] represents the window function value, N is the total number of points participating in the FFT operation, and j is the imaginary unit. is the rotation factor, and n is the sampling point index.

6. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The frequency of the TE signal is calculated based on the TE edge timestamp data, and the period dispersion is statistically analyzed to obtain TE signal characteristic data, including: Based on the TE edge timestamp data, the time difference between adjacent edge timestamps is calculated to obtain the TE period data; Calculate the average and reciprocal of the TE periodic data to obtain the TE signal frequency; Based on the TE cycle data, the average value of all cycles is calculated to obtain the average cycle. Based on the TE period data and the average period, the period jitter value is obtained by statistical calculation using the period jitter calculation formula. The TE signal frequency and the period jitter value are combined to obtain TE signal characteristic data.

7. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The mathematical expression for the period jitter calculation formula is as follows: ; In the formula, J te T represents the periodic jitter value. i It is the value of the i-th TE cycle, T avg It is the average of all TE period values, m is the number of TE edge timestamps, so (m-1) is the number of period values ​​Ti, and (m-2) is the degree of freedom when calculating the sample standard deviation, and i is the timestamp index.

8. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The step of comparing the PWM signal characteristic data and the TE signal characteristic data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test includes: Based on preset quality assessment rules, the PWM signal feature data and the TE signal feature data are compared one by one to obtain the comparison status of each feature data. A comprehensive logical judgment is made on the comparison status to obtain an overall judgment conclusion; Based on the overall judgment conclusion and the feature data that failed the comparison, a test judgment result containing diagnostic information is generated.

9. The method for testing the transmission signal of a liquid crystal display product as described in claim 1, characterized in that, The test judgment report generated based on the test judgment results includes: Based on the test results and diagnostic information, the results are output in real time through a preset output interface to generate display information that can be perceived by the operator. Based on the test results, raw data, process data, and associated metadata, the data is packaged and formatted to generate a test report.

10. A transmission signal testing system for a liquid crystal display product, characterized in that, The system includes: The signal acquisition and digitization module is used to acquire the PWM analog signal and TE digital signal of the liquid crystal display product under test, and to perform analog-to-digital conversion on the PWM analog signal to obtain PWM discrete timing data, and to perform edge capture on the TE digital signal to obtain TE edge timestamp data. The PWM signal frequency domain feature extraction module is used to perform Fast Fourier Transform (FFT) analysis on the PWM discrete time series data, extract preset frequency domain features from the obtained spectrum, and obtain PWM signal feature data. The TE signal time-domain feature extraction module is used to calculate the frequency of the TE signal based on the TE edge timestamp data, and to statistically analyze the period dispersion to obtain TE signal feature data. The comprehensive quality assessment and judgment module is used to compare the PWM signal characteristic data and the TE signal characteristic data with a preset quality threshold to generate a test judgment result for the liquid crystal display product under test. The test result output module is used to generate a test judgment report based on the test judgment results.

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