Synchronized LED Projection Control for Low-Power Image Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection devices in vehicles consume excessive electrical energy while maintaining high visual rendering quality, and there is a need to reduce energy consumption without compromising image quality or causing flickering.
Innovation Solution
An image projection device that alternates between two different duty cycles for the LED: a high duty cycle for image display mode to maintain brightness and a low duty cycle for image change mode to reduce energy consumption, combined with a higher peak current during image change to ensure efficient energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a high-speed rotating mirror is used to sequentially reflect light from red, green, and blue LEDs, then full-color projection is achieved, but mechanical failure occurs due to high-speed rotation demands
Solution Approach 1:
The patent replaces the mechanical rotating mirror system with a digital micromirror device (DMD) that uses electronically controlled micro-mirrors. Each micro-mirror can be independently tilted by applying voltage, eliminating the need for high-speed mechanical rotation while achieving the same color separation and projection function through electronic control of the micro-mirror array.
2Illumination intensity
If red, green, and blue LEDs are operated at high current to achieve high luminous intensity, then projection brightness is improved, but LED lifetime is reduced due to excessive current stress
Solution Approach 1:
The patent employs dynamic current modulation where the LED currents are adjusted in real-time based on the synchronization signal and image data requirements. Rather than operating LEDs at constantly high current, the system dynamically controls current levels and timing to achieve necessary brightness while reducing overall stress and heat generation, thereby extending LED operational life.
Solution Approach 2:
The system uses periodic pulsing of LED currents synchronized with the image refresh rate. By delivering high current in short, synchronized pulses rather than continuous operation, the LEDs achieve high peak brightness when needed while having rest periods that reduce thermal accumulation and extend component lifetime.
3Ease of operation
If conventional LED projection systems are used without synchronization, then simple operation is maintained, but image quality deteriorates due to non-synchronized LED output
Solution Approach 1:
The patent implements a synchronization signal that coordinates LED current modulation with the image projection timing. This feedback mechanism ensures that LED output is precisely synchronized with the image data being projected, maintaining accurate color representation and image quality while keeping the control system integrated and relatively simple.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces energy consumption by up to 90% while maintaining consistent visual rendering quality and preventing flickering by optimizing LED operation with varying duty cycles and peak currents.
Implementation Method 1
An image projection device comprises a red LED, a green LED, and a blue LED
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
The invention relates to a device comprising an LED powered by an electric current (I) and arranged to illuminate an image to be projected, and also to an image change module that makes it possible to replace the image to be projected with another image, the device being configured to operate, alternatingly: - in an image display mode (S1), in which the image present in the path of the illumination beam is held in position and in which the electric current varies over time (t) with a first duty cycle and a first peak current (11), and - in an image change mode (S2) in which the electric current varies with a second duty cycle which is smaller than the first duty cycle and with a second peak current (I2) which is greater than the first peak current, and in which the image present in the path of the light beam is replaced with another image.