LED Driving Pulse Generation for Precise Brightness Without Flicker
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED driving circuits face challenges in accurately controlling current to prevent damage while ensuring efficient light emission, particularly in achieving desired brightness levels and flicker-free operation.
Innovation Solution
A signal generating circuit utilizing a Time-Average-Frequency Direct Period Synthesis (TAF-DPS) method to generate pulse signals with precise frequency and duty cycle control, allowing for flexible and high-precision control of LED lighting effects, including brightness adjustment based on user input or ambient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional LED driving circuits are used, then simple circuit structure is achieved, but current control precision is insufficient leading to potential LED damage and flicker
Solution Approach 1:
The patent implements high-precision current control by dynamically adjusting pulse width parameters based on LED forward voltage characteristics. The control circuit calculates optimal pulse widths using the formula t_on = (V_target - V_forward) / (dI/dt), adapting parameters in real-time to maintain precise current control without increasing overall circuit complexity.
Solution Approach 2:
The patent replaces complex analog current control circuits with a digital pulse width modulation approach. By using a microcontroller to generate and control PWM signals, the system achieves high-precision current control through software-based parameter calculation and adjustment, eliminating the need for complex analog components while improving control accuracy.
2Illumination intensity
If high brightness is achieved through increased current, then illumination intensity improves, but risk of LED damage increases
Solution Approach 1:
The patent employs periodic pulse width modulation to control LED current. Instead of continuous high current that could damage the LED, the system delivers current in controlled periodic pulses with adjustable width. This allows the LED to achieve high average brightness through cumulative pulse effects while individual pulse durations remain short enough to prevent thermal damage and extend LED lifespan.
Solution Approach 2:
The patent implements dynamic current control by continuously monitoring LED forward voltage and adjusting pulse width parameters in real-time. The control algorithm adapts pulse characteristics based on instantaneous LED state, ensuring brightness requirements are met while maintaining current levels within safe operating limits. This dynamic adjustment prevents both under-driving (insufficient brightness) and over-driving (LED damage).
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
The solution provides low-cost, flexible, and high-precision control over LED lighting, enabling efficient light emission with improved performance and user-interactivity, ensuring safe operation by preventing excessive current while maintaining flicker-free illumination.
Implementation Method 1
When a suitable voltage is applied to the light emitting diode, holes injected from a P region into an N region and electrons injected from the N region into the P region are recombined within a few micrometers near the PN junction to generate spontaneous radiation fluorescence (i.e., electroluminescence).
Data Source
AI summary
A signal generating circuit and a signal generating method, a driving circuit of a light emitting device and a display device. The signal generating circuit includes: a control circuit, configured to calculate at least one of frequency control word information or duty-cycle control word information according to an instruction; and a pulse-width adjusting circuit, configured to generate a pulse signal according to the at least one of the frequency control word information or the duty-cycle control word information.