Abstract

Regarding the current energy consumption issues of LEDs, this article discusses the present state of energy-saving technologies for LED displays and also explores future research directions.

1. Introduction

In the digital age, LED displays have become a crucial medium for information dissemination, widely used in advertising, conferences, exhibitions, and other fields. However, with the rapid increase in the number of LED displays, their energy consumption issues have become increasingly prominent. Achieving energy saving in LED displays while ensuring display quality¹ has become a focal point of concern both within and outside the industry. This article will discuss the current status and future trends of energy-saving technologies for LED displays.

2. Current Technologies of Energy-Saving  in LED Displays

Currently, energy-saving in LED displays is approached from multiple dimensions, including power supplies, integrated circuits (ICs), LED beads, and control systems, which has significantly reduced energy consumption. However, there still remain some challenges, such as high costs, incomplete energy-saving standards, and varying levels of energy-saving technology among different manufacturers. Below are three common energy-saving methods.

2.1 Common Cathode Energy Saving

The common cathode energy-saving technology for LED displays improves efficiency and performance mainly by optimizing the power supply method². Specifically, this technology separates the power supply for the RGB (Red, Green, Blue) LEDs and precisely allocates the voltage for each color, as shown in Figure 1.

This design allows the current to flow directly from the LED to the negative terminal of the integrated circuit, significantly reducing the forward voltage drop and minimizing the conduction resistance, leading to a notable improvement in the energy utilization efficiency of the display. Additionally, this design can lower the heat generated by the display, extend the lifespan of the LED beads, and enhance the color accuracy and stability of the LED display. However, this approach requires more complex driving circuits and control systems, which increases the overall cost.

2.2 Black Screen Energy-Saving

The black screen energy-saving technology for LED displays is a technique that reduces power consumption and achieves energy savings when the screen is in a black screen state. The black screen energy-saving chip in the LED display continuously monitors the content being displayed. When it detects that certain areas of the screen are not showing content, it intelligently adjusts the power output for those areas, leading to a significant reduction in power consumption. Figure 2 illustrates a diagram showing the power consumption ratio of different areas in black screen energy-saving mode. In addition to real-time monitoring and power adjustment, black screen energy-saving technology also includes several practical energy-saving functions. For instance, the scheduled black screen setting allows users to configure the screen to automatically enter a black screen state during specific time periods, further reducing power consumption. The intelligent sleep mode automatically transitions the screen to a low-power state when there is no activity or viewing for an extended period, saving energy and extending the lifespan of the display. However, this technology currently faces drawbacks such as unnatural screen transitions and response delays, which can impact the viewing experience.

2.3 Dynamic Energy-Saving

LED display dynamic energy-saving technology is an advanced environmental and performance optimization technique that adjusts the brightness levels of LED displays based on real-time changes in ambient light and the actual demands of the displayed content. This technology not only effectively reduces energy consumption and extends the display’s lifespan but also ensures that viewers experience optimal visual quality under various lighting conditions. The system operates by using light sensors to detect subtle changes in ambient illumination in real-time. An intelligent control algorithm then processes this data, along with the content being displayed, to quickly calculate the ideal brightness level, which the LED display adjusts accordingly. However, this technology currently faces challenges such as response time delays and precision errors, particularly when the display content changes rapidly or when there are significant shifts in ambient lighting. Moreover, simply adjusting brightness may compromise other display parameters, such as grayscale levels and contrast, potentially affecting the overall display quality.

3. Future Trends in LED Display Energy- Saving

With the rapid advancement of artificial intelligence, new energy, and various new material technologies, LED display energy-saving technology is also experiencing significant new developments.

3.1 AI-Based Energy-Saving Model

The AI-based energy-saving model consists of three main components: the perception layer, processing layer, and application layer, as shown in Figure 3. The perception layer gathers data like lighting and foot traffic using various sensors. The processing layer uses AI algorithms to analyze this data and determine optimal brightness and energy settings. The application layer displays content based on these settings while continuously feeding data back to the processing layer for real-time adjustments, ensuring the best display results. Below are three typical scenarios where the AI-based energy-saving model is applied.

Smart Dynamic Energy-Saving: By leveraging AI algorithms and big data analysis, this technology dynamically adjusts brightness, contrast, grayscale levels, and other parameters in real time based on factors like ambient light, viewing requirements, and display content. For instance, when ambient light is low, the system increases screen brightness to enhance clarity while also fine-tuning contrast and grayscale. This ensures optimal viewing quality while saving energy.

Smart Control Energy-Saving: AI can optimize the control system of LED displays for more efficient energy management. By analyzing big data, AI algorithms can predict user viewing needs and adjust display parameters in advance to match expected content, thereby avoiding unnecessary energy consumption. Additionally, AI can develop predictive models for power usage, allowing for the efficient distribution of electrical power to achieve energy-saving goals.

Crowd Monitoring Energy-Saving: This system uses high-precision sensors and advanced image processing technology to capture and analyze real-time crowd data in the viewing area. When the system detects prolonged absence of people or extremely low foot traffic, it automatically reduces the LED display brightness or switches to sleep mode to minimize unnecessary energy consumption. The brightness adjustment is gradual and smooth, ensuring energy efficiency while avoiding discomfort for viewers due to sudden changes.

3.2 Energy-Efficiency Improvement-Based Energy-Saving Model

Enhancing energy conversion efficiency not only reduces energy consumption but also decreases heat generation, thereby extending the lifespan of the display. This approach is increasingly being explored and studied.

New LED Light-Emitting Chips: LED chips are the core components of LED displays, and their light-emitting efficiency directly impacts the display’s energy consumption. Therefore, continuous exploration and development of new LED light-emitting chips are essential. These new chips should offer higher light-emitting efficiency and lower energy consumption while maintaining display quality, significantly reducing the energy usage of LED displays.

Quantum Dot Color Conversion Technology: Quantum dots are nanometer-sized semiconductor particles that emit light at specific wavelengths when subjected to an electric field or light pressure³. Quantum dot color conversion technology offers high color purity, efficiency, and adjustability. Integrating quantum dot technology with LED displays can enhance display quality and improve energy conversion efficiency.

High-Efficiency Conversion Power Supplies: Using power supplies with Power Factor Correction (PFC) improves power factor by aligning the phase difference between current and voltage, thus enhancing energy conversion efficiency and reducing reactive power losses⁴. Typically, power supplies with PFC modules achieve efficiencies above 87%, while those without PFC modules have efficiencies around 60%. Figure 4 shows the energy consumption of different power supplies. Future developments will focus on achieving higher power factor correction to further improve energy savings.

3.3 Energy-Saving Model Based on Energy Storage and Renewable Energy Technologies

With the increasing application of technologies such as solar and wind energy, and their maturity, it is feasible to create a combined solar and wind power generation system for LED displays. However, the variability of solar and wind energy means that the power generated is not always stable. To address this issue, energy storage battery systems can be introduced. These systems store excess energy when available and release it when needed to ensure stable operation of the LED display. Additionally, the energy storage system features intelligent management, automatically adjusting charge and discharge strategies based on the LED display’s power needs and weather forecasts for optimal energy utilization. Furthermore, this system can interact with the grid. When power generation exceeds the LED display’s demand, surplus energy can be sold to the grid. Conversely, when energy is insufficient, the system can draw from the grid, purchasing low-cost nighttime electricity to supplement energy. Figure 5 illustrates this energy-saving model.

4. Conclusion

As a crucial medium for modern information display, the innovation in energy-saving technologies for LED displays is of significant importance for advancing the industry’s sustainable development. Energy savings not only lower operating costs but also reduce carbon emissions, aligning with the global trend towards sustainability. In the future, with advancements in smart technology, the use of eco-friendly materials, and continuous innovation in efficient energy-saving technologies, LED displays are expected to usher in a new era of low-carbon, green, energy-efficient, and environmentally friendly displays.

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