A system for replacing LCD screens with OLED screens based on FPGA

Abstract

This invention, applied to the field of product communication technology, discloses a system for replacing an LCD screen with an OLED screen based on an FPGA. The system comprises a MIPI decoding unit, a RAM image cache unit, a clock recovery unit, a scaling interpolation unit, an output timing unit, a MIPI encoding unit, a screen command unit, and an ADC sampling unit. The system utilizes only the Lattice‑XO3 FPGA. This FPGA-based system for replacing an LCD screen with an OLED screen employs a scaling interpolation unit based on the FPGA's internal RAM cache to address the issue of inconsistent resolutions between LCD and OLED screens. This system offers high flexibility and adaptability. Through precise interpolation calculations and scaling processing, the system ensures image quality and integrity, enhancing the visual experience. It also enables users to fully utilize the high resolution of the OLED screen after the screen replacement, while avoiding issues such as image distortion, blurring, or incomplete display that can result from resolution mismatches.

Description

Technical Field

[0001] The present invention relates to the field of product communication technology, and in particular to a system for replacing an LCD screen with an OLED screen based on FPGA. Background Art

[0002] In today's electronics market, LCD (liquid crystal display) and OLED (organic light-emitting diode display) are the two most common display technologies. They are widely used in various devices such as televisions, computer monitors, mobile phones, and tablets. Although both are display technologies, they have significant differences in structure, performance, and user experience. The working principle of LCD screens is based on the arrangement and twisting of liquid crystal molecules to control the passage of light. Liquid crystal molecules will change their arrangement under the action of a specific electric field, thereby controlling the degree of light penetration and displaying different colors and brightness. This technology requires a backlight layer to provide a light source, so the LCD screen is relatively thick in structure. The OLED screen uses a completely different working principle. It uses the self-luminous characteristics of organic materials. When current passes through, the organic material will directly emit light. This technology does not require a backlight layer, so the OLED screen can be thinner and lighter. In addition, since each pixel can independently control the light emission, the OLED screen can almost emit no light when displaying black, thereby achieving higher contrast and more vivid colors. OLED screens are gradually favored by the high-end market due to their excellent color performance and contrast. Although the manufacturing cost is relatively high, OLED screens are increasingly used in high-end TVs, mobile phones, tablets and other fields. With the advancement of technology and the increase in production, the price of OLED screens is also gradually decreasing, and they are favored by more and more consumers. In daily work and life, it is common for screens to be accidentally broken, which has also led to the increasingly popular market for repaired screens. At the same time, as the performance of CPUs is getting better and better, the performance has gradually become surplus, so the demand for consumers to replace their phones is also slowly slowing down. However, the technology of screens is changing with each passing day. From the beginning of LCD screens to the current OLED / MINI-LED and flexible screens, people's continuous pursuit of display effects is reflected. However, the performance of previous electronic devices can still meet the usage needs, but the screens are outdated products. To solve this problem, a system based on FPGA to replace LCD screens with OLED screens is proposed to solve the problem that LCD devices cannot be upgraded by replacing OLED screens. Summary of the Invention

[0003] The purpose of the present invention is to provide a system for replacing an LCD screen with an OLED screen based on FPGA, so as to solve the problem in the above background technology that the LCD device cannot be upgraded by replacing the OLED screen.

[0004] To achieve the above-mentioned object, the present invention provides the following technical solution: a system for replacing an LCD screen with an OLED screen based on FPGA, comprising a MIPI decoding unit, a RAM image cache unit, a clock recovery unit, a scaling interpolation unit, an output timing unit, a MIPI encoding unit, a screen command unit, and an ADC sampling unit. The FPGA selected for the system is only Lattice-XO3;

[0005] The MIPI decoding unit is used to parse the input MIPI video stream and process the command handshake protocol, and transmit the parsed video data to the RAM image cache unit;

[0006] The RAM image cache unit is used to store video data, and its output end is connected to the scaling interpolation unit;

[0007] The clock recovery unit generates the clock required by the internal processing unit through the PLL based on the input MIPI-RX clock, avoids shift overflow when reading and writing data in the RAM, and provides a synchronous clock signal for each unit;

[0008] The scaling interpolation unit obtains data from the RAM image buffer unit and implements resolution conversion through a bilinear interpolation algorithm;

[0009] The output timing unit follows the VSYNC signal of the input video stream and adjusts the timing according to the principle of total time invariance;

[0010] The MIPI encoding unit encodes the processed video stream into a format that complies with the MIPI protocol and drives the OLED screen display;

[0011] The screen command unit is used for initialization and real-time dimming control of the OLED screen, and realizes screen lighting and brightness adjustment through command interaction;

[0012] The ADC sampling unit detects the voltage of the LCD backlight circuit and establishes a mathematical model by recording the voltage values ​​corresponding to different brightness values, thereby providing a dimming parameter matching basis for the screen command unit.

[0013] Preferably, the MIPI decoding unit is used to parse the input MIPI video stream, including: first analyzing the LP state switching from LP11-LP01-LP00 to high-speed mode, then analyzing the packet header 00-00-00-00-00-B8 in the high-speed signal, and then analyzing the command packet SOT / EOT ​​to parse the video data stream signal therefrom;

[0014] The MIPI decoding unit is used to process the command handshake protocol, including: detecting the command sent by the host, analyzing the command that needs to be answered, and performing handshake processing. If the host does not receive a response, it enters a dormant state.

[0015] The above technical solution can accurately analyze various signals in the MIPI video stream, ensure the correct extraction of video data, and provide an accurate data source for subsequent processing, so that the picture display is smooth and without interruption, the video screen switches quickly in the game, and the scene transition is natural.

[0016] Preferably, the output timing unit follows the VSYNC in the input video stream and, in accordance with the principle of constant total time, inserts appropriate leading and trailing shoulders and effective values ​​of video blanking to ensure that the output is completely synchronized with the input timing to avoid frame skipping and freezes.

[0017] The above technical solution ensures perfect synchronization between output timing and input timing, eliminates frame skipping and freezes, and allows players to enjoy smooth and coherent images in games, especially in high-speed action scenes, improving the consistency and accuracy of game operations.

[0018] Preferably, the MIPI encoding unit re-encodes the processed video stream into the MIPI format, and then encodes the VS-Start (01.00.00.ECC), HS-Start (21.00.00.ECC) and DE-Start (3E.00.00.ECC) in the video stream into a data packet format, and then inputs the LP00-LP10-LP11 status into the underlying DPHY module to finally form a complete MIPI protocol format.

[0019] By adopting the above technical solution, the processed video stream is correctly encoded into a format that complies with the MIPI protocol, ensuring the accurate transmission and display of the video signal, so that the game screen can be presented on the screen in the correct format and parameters, with accurate colors and high clarity, bringing players a high-quality visual experience.

[0020] Preferably, the screen command unit inputs the initialization configuration file of the OLED screen into the initialization module, and uses the unified 0x11 and 0x29 commands to light up the screen. The screen command unit communicates with the screen in real time to adapt to different ambient brightness and perform real-time dimming.

[0021] By adopting the above technical solution, the screen initialization and real-time dimming functions are realized, so that the screen can automatically adjust according to the ambient brightness. During the game, no matter how the ambient light changes, players can clearly see the game screen. At the same time, the screen's fast response also ensures the timeliness and accuracy of game operations.

[0022] Preferably, the ADC sampling unit loads a suitable resistor on the LCD backlight circuit, then connects the converted voltage to the ADC sampling pin of the FPGA, and finally records the voltage values ​​corresponding to different brightness values ​​to form a mathematical model. The tested mathematical model is used to match the register value in the OLED corresponding to the LCD dimming process.

[0023] The above technical solution successfully solves the problem of the difference in LCD and OLED dimming methods and achieves precise dimming control. During the game, the screen brightness can be automatically adjusted according to the scene requirements, which not only protects the player's eyes, but also improves the contrast and layering of the game screen, enhancing the immersive feeling of the game.

[0024] Compared with the prior art, the beneficial effects of the present invention are: the system based on FPGA replacing the LCD screen with the OLED screen:

[0025] 1. A scaling interpolation unit based on the FPGA's internal RAM cache addresses the resolution inconsistency between LCD and OLED screens. This highly flexible and adaptable system ensures image quality and integrity through precise interpolation and scaling, enhancing the visual experience. It also allows users to fully utilize the high resolution of OLED screens after screen replacement while avoiding issues such as image distortion, blurring, or incomplete display caused by resolution mismatch.

[0026] 2. By loading appropriate resistors into the LCD backlight circuit and performing ADC sampling, a mathematical model of voltage and brightness values ​​is established to match the register values ​​in the OLED. This successfully resolves the differences in LCD and OLED dimming methods, enabling smooth and accurate dimming after screen replacement. The system ensures stable and reliable dimming under varying ambient light conditions and when users adjust screen brightness based on their personal preferences. Compared to traditional LCD dimming methods, OLED dimming can be more precise and achieve lower brightness levels, while avoiding the flickering problem that can occur with LCD at low brightness levels, thereby reducing eye fatigue and damage.

[0027] Furthermore, this innovative dimming conversion method provides key technical support for the integration of two different display technologies, breaking the technical barriers that limit screen replacement due to different dimming methods, and promoting the upgrading and diversified development of display technology.

[0028] 3. The clock recovery unit uses the input MIPI-RX clock as a template to obtain all clocks of the internal processing units through the PLL. This technology is of great significance to improving system performance and stability. During the screen replacement process, image data processing requires precise clock control, especially when it comes to operations such as image scaling based on the internal RAM cache. Through precise clock recovery, the system can ensure that data shift and overflow caused by clock deviation are avoided during the data reading and writing process. This means that at every stage of image transmission and processing, data can be operated according to the accurate timing, thus ensuring the integrity and accuracy of the image.

[0029] Furthermore, when using a device with a replaced OLED screen, there will be no image anomalies, screen distortion, or freezes. Whether in static image display or dynamic video playback, a stable and smooth visual experience can be obtained. From the perspective of overall system performance, clock recovery technology improves the reliability and stability of the system, providing a solid foundation for the normal operation of the device after the screen is replaced. It also enables the system to work stably in complex electronic equipment environments and adapt to various application scenarios.

[0030] 4. The output timing unit ensures complete synchronization of the output timing with the input timing by following the VSYNC (field synchronization signal) in the input video stream and adjusting the timing according to the principle of total time invariance. This effectively prevents abnormal situations such as frame skipping and freezing, ensuring that various image display scenarios such as video playback and game operations can remain coherent and smooth. From the perspective of system compatibility, this output timing synchronization technology enables this screen replacement system to work better with other components of the original device, eliminating the need for large-scale adjustments and modifications to the original device's hardware architecture, reducing the difficulty and cost of system integration.

[0031] 5. The Lattice-XO3 used in this system has the advantage of being small in size, which is of great significance in screen replacement applications. For electronic devices, internal space is often very limited, especially in some portable devices such as mobile phones and tablets. The smaller size of the FPGA makes it easier to integrate it into the original device's circuit board, without making large-scale changes to the device's internal structure. This not only reduces the difficulty and cost of installation, but also reduces the compatibility issues that may be caused by hardware changes. After the user replaces the screen, the overall appearance and size of the device will not be significantly affected, and the original portability and aesthetics will still be maintained.

[0032] Furthermore, after the screen is replaced, the overall power consumption of the device will not increase significantly due to the addition of the new system. The device can be used for a longer time without frequent charging, which improves the convenience of using the device. At the same time, low power consumption also helps to reduce the heat problem of the device during operation, extend the service life of the device, and reduce the risk of hardware failure caused by overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the screen replacement principle of the present invention;

[0034] Figure 2 This is a schematic diagram of the screen replacement system framework of the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] See also Figure 1-Figure 2 The present invention provides a technical solution: a system for replacing an LCD screen with an OLED screen based on FPGA. Example

[0037] 1. Preparation for implementation

[0038] 1. Equipment and tool preparation

[0039] A smartphone with a typical LCD screen is selected as the implementation object, with a screen resolution of 1080×2340 and a size of 6.1 inches;

[0040] Prepare an OLED screen that fits the size of the phone, with a resolution of 1440×3120 and a size of 6.1 inches. This OLED screen has self-luminous characteristics, a contrast ratio of 100,000:1, a brightness of up to 800 nits, and a pixel density of 538ppi;

[0041] The Lattice-XO3 FPGA development board was selected as the core processing unit. It has 5280 logic units, 176 I / O pins, and an operating frequency of up to 500 MHz, providing sufficient logic resources and I / O pins to meet system requirements.

[0042] Prepare several electronic components such as resistors and capacitors. The specific parameters are as follows:

[0043] Resistors: Select 10kΩ, 1kΩ, and 100Ω chip resistors with an accuracy of ±5% for circuit functions such as voltage division and current limiting;

[0044] Capacitors: 10μF, 0.1μF ceramic capacitors and 100μF electrolytic capacitors are selected, with voltage resistance values ​​of 16V, 50V, and 10V respectively, for circuit functions such as filtering and decoupling;

[0045] Electronic soldering tools, including a soldering iron (30W power, adjustable temperature range 200°C-450°C), solder wire (0.8mm diameter, 63% tin content), and flux (rosin-based flux), are used to connect the OLED screen to the FPGA development board and the mobile phone motherboard;

[0046] The oscilloscope with MIPI interface testing function, model Tektronix MDO3000, has a bandwidth of 1 GHz and a sampling rate of 5 GS / s, and is used to monitor and analyze signals during the debugging process.

[0047] 2. Software and Data Preparation

[0048] Download and install the development environment software for the FPGA development board, such as LatticeDiamond, to write and debug FPGA logic code.

[0049] Obtain the LCD screen initialization configuration file and related register parameter information provided by the mobile phone manufacturer so that corresponding configuration adjustments can be made after the screen is replaced. The LCD screen initialization command includes setting the pixel format to RGB565, the frame refresh rate to 60Hz, and the scanning mode to progressive scanning;

[0050] Prepare the initialization configuration file and driver provided by the OLED screen manufacturer to ensure that the OLED screen can initialize and work correctly. The initialization parameters of the OLED screen include setting the pixel arrangement to Pentile, the display mode to Normal mode, and the Gamma correction value to 2.2;

[0051] A database containing different brightness values ​​and corresponding voltage values ​​is established for data comparison and register value matching during the ADC sampling process. In the initial test, the voltage values ​​corresponding to the lowest brightness to the highest brightness (0-255 brightness levels) are recorded in the range of 0.1V-3.3V, with sampling and recording at intervals of 10 brightness levels. This database will be continuously improved and optimized during subsequent debugging.

[0052] 2. Implementation Steps

[0053] 1. Hardware connection and installation

[0054] Remove the original LCD screen from the mainboard, taking care to avoid damaging other components. During the disassembly process, note that the interface type connecting the LCD screen to the mainboard is a MIPI DSI interface, and the pin definitions include data channels 0-3, clock channel, power pin, and control pin.

[0055] Connect the OLED screen's cable to the corresponding interface on the FPGA development board. Design and make a suitable interface adapter board based on the OLED screen's specifications and the FPGA's pinout to ensure correct signal transmission. During the connection process, use soldering tools to firmly solder the cable to the pins on the adapter board to ensure a reliable connection and avoid problems such as cold soldering or short circuits. When soldering, set the soldering iron temperature to 350°C and the soldering time to 3-5 seconds to ensure soldering quality.

[0056] Connect the FPGA development board to the MIPI interface on the phone's motherboard via another set of cables. This set of cables needs to be customized according to the interface definitions of the phone's motherboard and FPGA development board to ensure signal compatibility and integrity. Once connected, secure the FPGA development board and OLED screen in a suitable position inside the phone to ensure they do not affect the normal operation of other components of the phone. At the same time, ensure good heat dissipation. Attach heat dissipation silicone sheets to the back of the FPGA development board and OLED screen to enhance heat dissipation.

[0057] 2.FPGA logic code development and configuration

[0058] In the development environment software LatticeDiamond, create a new project and write FPGA logic code according to the system's functional requirements;

[0059] Implement the functions of the MIPI decoding unit, including video stream parsing and command handshake protocol. According to the MIPI protocol specification, write code to identify the switching of LP state. When the LP state switches from LP11-LP01-LP00 to high-speed mode, start parsing the packet header 00-00-00-00-00-B8 in the high-speed signal, then analyze the command packet SOT / EOT, etc., and extract the video data stream signal from it. For the command handshake protocol, set the detection period to 10μs, detect the commands sent by the host in real time, analyze the commands that need to be answered, and perform handshake processing to ensure that the host does not enter the sleep state due to lack of response.

[0060] Design and implement a RAM image cache unit: Because the OLED screen has a higher resolution than the original LCD screen, the image needs to be scaled. Based on the RAM resources within the FPGA, 1MB of cache space is allocated to store image data. Code is written to implement the image data cache and read control logic. The cache write clock frequency is set to 100MHz and the read clock frequency is set to 120MHz to ensure correct data storage and reading during the scaling process.

[0061] Develop a clock recovery unit: Using the input MIPI-RX clock as a reference, the PLL module generates various clock signals required by the internal processing units. The PLL parameters are configured to output clock frequencies of 120 MHz, 150 MHz, 200 MHz, and so on. The phase offset is controlled within ±1° to meet the system's accuracy requirements and prevent data shift and overflow during image scaling and processing.

[0062] Write code for the scaling interpolation unit: This unit implements scaling from the original LCD screen resolution (1080×2340) to the OLED screen resolution (1440×3120) using a predetermined interpolation algorithm. For each pixel, it retrieves four adjacent points from the RAM cache for bilinear calculations. The decimal fraction of the coordinates is used as the interpolation coefficient K. The interpolated pixel value is calculated using the formula K*X+(1-K)Y. The calculations are performed intra-row, two pixels at a time. After a row is calculated, inter-row calculations are performed, gradually completing the scaling of the entire image. During the calculation process, the data processing precision is set to 16 bits to ensure image quality.

[0063] Build an output timing unit: Monitor the VSYNC field synchronization signal in the input video stream. Based on the principle that the total time of each frame is constant at 1 / 60 second at a 60 refresh rate, calculate and generate appropriate front and back porch and video blanking effective values. Set the front porch time to 10μs, the back porch time to 20μs, and the video blanking time to 5μs to ensure that the output video timing is completely synchronized with the input timing to avoid frame skipping and freezes.

[0064] Implement the functions of the MIPI encoding unit: encode the processed video stream data into a data packet format according to the packaging method specified in the MIPI protocol, including VS-Start (01.00.00.ECC), HS-Start (21.00.00.ECC), and DE-Start (3E.00.00.ECC). Combine the encoded data packet with the LP00-LP10-LP11 status and input it into the underlying DPHY module according to the timing requirements of the MIPI protocol. Finally, a complete MIPI protocol format is formed. The data packet transmission rate is set to 1Gbps to meet the requirements of high-speed data transmission.

[0065] Implement the functions of the screen command unit: Based on the initialization configuration file provided by the OLED screen manufacturer, input parameters such as resolution information (1440×3120), pixel pitch (0.05mm), scanning mode (line-by-line scanning), and gamma correction value (2.2) into the initialization module. Finally, use the unified 0x11 and 0x29 commands to light up the display. During screen use, to adapt to different ambient brightness levels, the command unit communicates with the screen in real time, setting the dimming step size to 10 levels, that is, 100 adjustable levels from minimum to maximum brightness. Based on the feedback value of the ambient light sensor, the brightness of the OLED screen is adjusted in real time;

[0066] Implement the ADC sampling unit: Add a 1kΩ resistor to the LCD backlight circuit and connect the converted voltage to the FPGA's ADC sampling pin. Set the ADC sampling frequency to 1kHz and sample the voltage at different brightness levels. Finally, record the voltage values ​​corresponding to different brightness levels to form a mathematical model. Based on this tested mathematical model, use a lookup table or algorithm to match the corresponding OLED register value during the LCD dimming process to achieve accurate dimming control.

[0067] 3. System debugging and optimization

[0068] 1. Functional testing

[0069] Turn on the phone and check whether the screen lights up normally, whether the displayed image is clear and complete, and whether there is any screen distortion or flickering. Observe whether the color display is normal. Compare the color saturation and contrast of the OLED screen and the original LCD screen to ensure that the advantages of the OLED screen are reflected.

[0070] Test whether the touch function is normal: by clicking, sliding, and other operations on the screen, check whether the touch response is accurate and sensitive, and whether the interaction with the mobile phone system is smooth;

[0071] Verify video playback: Play video files of different resolutions and frame rates to see if the video plays smoothly, whether the images are synchronized, and whether there are any issues such as lag or frame skipping. Also, check the color reproduction and clarity of the video, especially when playing high-definition videos, to observe the OLED screen's ability to render details.

[0072] 2. Performance Testing

[0073] Use professional testing software, such as DisplayMate, to test various performance indicators of the OLED screen, including brightness uniformity, color accuracy, contrast, and viewing angle. Record the test data and compare it with the OLED screen's specifications to ensure that the screen performance meets expectations.

[0074] Test the system's power consumption: Use a power analyzer to measure changes in the phone's power consumption in different operating states (such as standby, talking, browsing the Internet, and gaming). Compare the power consumption data before and after replacing the OLED screen to evaluate the system's power optimization effects. This ensures that the phone's battery life is not significantly affected after the screen upgrade, and may even be improved in some cases (for example, due to the self-luminous nature of the OLED screen, power consumption is lower when displaying black).

[0075] Test the system's response time, including screen touch response time and system interface switching time. Use high-speed cameras and professional testing tools to record and analyze the system's response time under different operations to ensure it meets user requirements for operational smoothness. Response time should be within the human perceptible range. Generally, touch response time should not exceed 100ms, and system interface switching time should not exceed 500ms.

[0076] 3. Debugging and optimization

[0077] Based on the results of functional and performance tests, debug and optimize the system. If any image display issues are found, such as noise or streaks, check the code logic of the MIPI decoding and encoding units, as well as the reliability of the hardware connections, to ensure correct parsing and transmission of video stream data.

[0078] For the problem of inaccurate colors: adjust the gamma correction value and color space conversion algorithm, and continuously optimize the color parameters by comparing the standard color samples with the actual display effect to achieve more accurate color reproduction;

[0079] If the touch screen is not responsive or you experience false touches, check the touch driver and touch controller configurations, optimize the touch algorithm, and adjust the touch sensitivity and threshold to ensure the accuracy and stability of touch operations.

[0080] In terms of power consumption optimization: If power consumption is too high, analyze the power consumption distribution of each module in the system and find the part with the highest power consumption. If the power consumption of the FPGA is too high, optimize its logic code, reduce the operating frequency or reduce unnecessary logical operations. For OLED screens, adjust its brightness control strategy. While ensuring the display effect, reduce the screen brightness to reduce power consumption.

[0081] To address the issue of long system response time: optimize the system's software architecture and algorithm flow, improve data processing speed, optimize the image scaling and interpolation algorithm, reduce the amount of calculation, optimize the data transmission rate and timing control of the MIPI interface, ensure that data can be transmitted to the screen quickly and accurately, thereby shortening the response time.

[0082] Test results

[0083] 1. Image display quality test results

[0084] 1. Resolution adaptation test

[0085] Test Equipment and Methods: We used the professional image analysis software ImageJ to analyze images displayed on LCD devices with different resolutions (three devices with 720p and three with 1080p resolutions, respectively) after replacing the OLED screen. Standard test patterns, including lines, grids, and fine text, were displayed on the screens, and the software was used to measure the actual resolution and clarity of the images on the OLED screens.

[0086] Test result data:

[0087] When the 720p LCD device is replaced with an OLED screen, the actual resolution of the image on the OLED screen reaches the expected target resolution, with an average error of less than ±2 pixels;

[0088] In terms of image clarity, by calculating the image's edge sharpness and modulation transfer function (MTF), it was found that the MTF value in the high-frequency part is significantly improved compared to the original LCD screen, with an average improvement of about 20%. When displaying lines and text, the edges are clearer and the legibility is significantly improved;

[0089] When replacing 1080p LCD devices with OLED screens, resolution adaptation remains equally accurate, with an average error of less than ±1 pixel, resulting in even better image detail.

[0090] When displaying complex patterns, more details can be clearly distinguished, and the overall image clarity score (calculated based on a weighted calculation of multiple clarity indicators) is about 15% higher than the original LCD screen;

[0091] 2. Color performance test

[0092] Test Equipment and Methods: A professional color calibrator (X-Rite i1 Pro) was used to measure the color of the OLED screen and the original LCD screen. Under the same test environment (standard illuminant D65, 200 nits brightness), a series of standard color samples were displayed. The color parameters of the OLED and LCD screens were recorded, including color gamut coverage, color accuracy (ΔE value), and color saturation.

[0093] Test result data:

[0094] Color gamut coverage: The OLED screen's color gamut coverage is 96% NTSC, while the original LCD screen's color gamut coverage is 75% NTSC, an increase of 21 percentage points.

[0095] Color accuracy (ΔE value): The average ΔE value of the OLED screen is less than 2 (the smaller the ΔE value, the higher the color accuracy). When displaying common colors, the ΔE value is mostly between 1-1.5, while the average ΔE value of the original LCD screen is between 3-4. When displaying red, the ΔE value of the OLED screen is 1.2, and the ΔE value of the LCD screen is 3.5. When displaying green, the ΔE value of the OLED screen is 1.1, and the ΔE value of the LCD screen is 3.8.

[0096] Color saturation: Through analysis of multiple color samples, it was found that OLED screens are more intense and vivid when displaying bright colors. When displaying blue, the color saturation value of the OLED screen is 85%, while the color saturation value of the LCD screen is 65%, an increase of 20 percentage points.

[0097] 3. Contrast test

[0098] Test Equipment and Methods: A luminance meter was used to measure the brightness of the OLED and LCD screens when displaying all-black and all-white images, respectively, and the contrast ratio was calculated. The tests were conducted in a darkroom to reduce the influence of ambient light.

[0099] Test result data:

[0100] The contrast ratio of OLED screens reaches over 100,000:1, while the contrast ratio of traditional LCD screens is usually between 1,000:1 and 1,500:1. The brightness of OLED screens when displaying a completely black image is 0.01 nits, and when displaying a completely white image is 100 nits, with a contrast ratio of 10,000:1. The brightness of traditional LCD screens when displaying a completely black image is 0.5 nits, and when displaying a completely white image is 500 nits, with a contrast ratio of 1,000:1. The contrast ratio of OLED screens has been significantly improved compared to LCD screens, making the image layering more distinct and the dark details more clearly visible.

[0101] 2. System Performance Test Results

[0102] 1. Frame rate and fluency test

[0103] Test Equipment and Methods: The frame rate of the input video stream is monitored using professional video frame rate testing software (such as Fraps). Different types of videos (including HD movies, game videos, and dynamic demonstration videos) are played on the OLED screen. A high-speed camera is used to record the screen image and analyze the smoothness of the image and whether there are any frame skipping or lag issues.

[0104] Test result data:

[0105] When the input video stream frame rate is 30fps and 60fps, the output frame rate on the OLED screen after system processing remains stable at the same level as the input frame rate, with a frame rate fluctuation range of less than ±0.5fps. When playing HD movies, there is no frame skipping or stuttering during the entire playback process, and the picture is smooth. Through frame-by-frame analysis of the images recorded by the high-speed camera, it was found that in a video played continuously for one hour, there were no frame skips and the total stuttering time did not exceed one second. The stuttering was very slight and barely affected the viewing experience. When playing games and dynamic demonstration videos, the picture can also be displayed in real time and accurately, with a fast response speed, meeting the user's requirements for smoothness.

[0106] 2. Response time test

[0107] Test Equipment and Methods: A response time tester (Tektronix TDS3000 series oscilloscope) was used to measure the response time of the OLED screen and the original LCD screen. A rapidly changing black and white pattern was displayed on the screen, and the oscilloscope measured the time interval from signal input to the corresponding change on the screen.

[0108] Test result data:

[0109] The average response time of an OLED screen is 0.1ms-0.5ms, while the response time of an original LCD screen is usually between 5ms-10ms. On the test equipment, the response time of the OLED screen is 0.3ms, and the response time of the LCD screen is 8ms. The response time of the OLED screen is significantly shorter than that of the LCD screen. This allows for more clear and accurate capture of every moment of change when displaying fast-moving images, reducing the occurrence of smearing and blurring. The advantages of the OLED screen are particularly obvious when performing fast-swiping screen operations or watching high-speed moving objects, and users can experience a smoother and clearer visual experience.

[0110] 3. Power consumption test results

[0111] 1. Test Equipment and Methodology: A power analyzer (Keysight N6705C) was used to measure the power consumption of a system in which the FPGA-based LCD screen was replaced with an OLED screen in different operating states (standby, video playback, and game operation). The power consumption was compared with the power consumption of the original LCD screen system. The tests were conducted under the same environmental conditions and the device brightness was set to the same level (200 nits).

[0112] 2. Test result data:

[0113] Standby power consumption:

[0114] The average standby power consumption of the FPGA-based OLED system is 0.1W-0.3W, while the average standby power consumption of the original LCD screen system is 0.5W-1W. On the test equipment, the standby power consumption of the OLED system is 0.2W, and the standby power consumption of the LCD system is 0.8W, which is about 75% lower than the standby power consumption of the OLED system.

[0115] Power consumption when playing video:

[0116] When playing 1080p HD video, the OLED system consumes an average of 1.5W-2W, while the original LCD screen system consumes an average of 2.5W-3W. On the test equipment, the OLED system consumes 1.8W while the LCD system consumes 2.8W, reducing the OLED system's power consumption by approximately 36%.

[0117] Power consumption when running games:

[0118] When running large 3D games, the OLED system consumes an average of 2.5W-3.5W of power, while the original LCD screen system consumes an average of 4W-5W of power. On the test equipment, the OLED system consumes 3W of power while running games, while the LCD system consumes 4.5W of power, reducing the OLED system's power consumption by approximately 33%.

[0119] 4. Stability and reliability test results

[0120] 1. Long-running tests

[0121] Test Equipment and Methods: A system with an FPGA-based LCD screen replaced with an OLED screen was placed in continuous operation. Automated testing software was used to continuously loop videos, run applications, and perform screen operations. Failures and performance changes during operation were recorded. The test lasted 72 hours.

[0122] Test result data:

[0123] During the 72-hour continuous operation test, the system did not experience any freezes, reboots, or other serious failures. Only once, at the 48th hour of operation, did the screen flicker briefly, but the system automatically recovered in about 0.5 seconds. System performance remained generally stable throughout the test, with no significant fluctuations in indicators such as CPU utilization and memory usage. CPU utilization was 30%-40% at the start of the test and remained in this range at the end. Memory utilization remained between 60%-70% throughout the test.

[0124] 2. Environmental adaptability test

[0125] Test Equipment and Methods: The system was placed under various environmental conditions, including temperatures ranging from -20°C to 60°C and humidity ranging from 20%RH to 90%RH. Electromagnetic interference (EMI) tests were performed using a standard EMI generator, applying EMI signals of varying intensities. The system's operating status and image display quality were observed under these conditions.

[0126] Test result data:

[0127] In the temperature test:

[0128] When the ambient temperature is -20℃, the system startup time is slightly extended, about 1.2 times the normal startup time, but it can work normally after startup, and there is no obvious abnormality in the image display. The screen brightness and color are slightly reduced by about 10%, but it can still be viewed clearly;

[0129] In a high-temperature environment of 60°C, the system ran stably, images were displayed normally, and screen brightness increased slightly by about 5%. No overheating, freezing, or other malfunctions occurred.

[0130] During humidity testing:

[0131] In a dry environment with a humidity of 20% RH, the system works normally without any abnormal phenomena;

[0132] When the humidity reaches 90%RH, the system operates stably and the image is clear without any short circuit, leakage or blurred image.

[0133] In electromagnetic interference testing:

[0134] When the applied electromagnetic interference intensity is less than 1V / m, the system is not affected and the image display and performance are normal;

[0135] When the electromagnetic interference intensity is between 1V / m and 5V / m, the system will have slight image noise, but it will not affect normal viewing and use;

[0136] When the electromagnetic interference intensity is greater than 5V / m, the image flickers and is distorted briefly, but the system can still operate without serious problems such as freezing or data loss. After the electromagnetic interference is removed, the system can quickly return to normal operation.

[0137] Through the detailed test results data above, it can be seen that the system that replaces the FPGA-based LCD screen with the OLED screen has achieved good results in image display quality, system performance, power consumption, stability and reliability, and can provide users with a better visual experience and more reliable use guarantee.

[0138] The above specific embodiments further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A system for replacing an LCD screen with an OLED screen based on FPGA, characterized by: Including MIPI decoding unit, RAM image cache unit, clock recovery unit, scaling interpolation unit, output timing unit, MIPI encoding unit, screen command unit and ADC sampling unit, the FPGA selected for this system is only Lattice-XO3; The MIPI decoding unit is used to parse the input MIPI video stream and process the command handshake protocol, and transmit the parsed video data to the RAM image cache unit; The RAM image cache unit is used to store video data, and its output end is connected to the scaling interpolation unit; The clock recovery unit generates the clock required by the internal processing unit through the PLL based on the input MIPI-RX clock, avoids shift overflow when reading and writing data in the RAM, and provides a synchronous clock signal for each unit; The scaling interpolation unit obtains data from the RAM image buffer unit and implements resolution conversion through a bilinear interpolation algorithm; The output timing unit follows the VSYNC signal of the input video stream and adjusts the timing according to the principle of total time invariance; The MIPI encoding unit encodes the processed video stream into a format that complies with the MIPI protocol and drives the OLED screen display; The screen command unit is used for initialization and real-time dimming control of the OLED screen, and realizes screen lighting and brightness adjustment through command interaction; The ADC sampling unit detects the voltage of the LCD backlight circuit and establishes a mathematical model by recording the voltage values ​​corresponding to different brightness values, thereby providing a dimming parameter matching basis for the screen command unit.

2. The system for replacing an LCD screen with an OLED screen based on FPGA according to claim 1, characterized in that: The MIPI decoding unit is used to parse the input MIPI video stream, including: first analyzing the LP state switching from LP11-LP01-LP00 to high-speed mode, then analyzing the packet header 00-00-00-00-00-B8 in the high-speed signal, and then analyzing the command packet SOT / EOT ​​to parse the video data stream signal; The MIPI decoding unit is used to process the command handshake protocol, including: detecting the command sent by the host, analyzing the command that needs to be answered, and performing handshake processing. If the host does not receive a response, it enters a dormant state.

3. The system for replacing an LCD screen with an OLED screen based on FPGA according to claim 1, characterized in that: The output timing unit follows the VSYNC in the input video stream and, in accordance with the principle of constant total time, inserts appropriate leading and trailing shoulders and effective values ​​of video blanking to ensure that the output is completely synchronized with the input timing to avoid frame skipping and freezes.

4. The system for replacing an LCD screen with an OLED screen based on FPGA according to claim 1, characterized in that: The MIPI encoding unit re-encodes the processed video stream into the MIPI format, and then encodes the VS-Start (01.00.00.ECC), HS-Start (21.00.00.ECC) and DE-Start (3E.00.00.ECC) in the video stream into a data packet format, and then combines the LP00-LP10-LP11 status to input the underlying DPHY module, finally forming a complete MIPI protocol format.

5. The system for replacing an LCD screen with an OLED screen based on FPGA according to claim 1, characterized in that: The screen command unit inputs the initialization configuration file of the OLED screen into the initialization module, and uses the unified 0x11 and 0x29 commands to light up the screen. The screen command unit communicates with the screen in real time to adapt to different ambient brightness and perform real-time dimming.

6. The system for replacing an LCD screen with an OLED screen based on FPGA according to claim 1, characterized in that: The ADC sampling unit loads a suitable resistor on the LCD backlight circuit, then connects the converted voltage to the ADC sampling pin of the FPGA. Finally, the voltage values ​​corresponding to different brightness values ​​are recorded to form a mathematical model. The tested mathematical model is used to match the register value in the OLED corresponding to the LCD dimming process.

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