LED Backlight Thermal and Optical Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Backlight modules with light emitting diodes experience brightness and color decay due to temperature increases and aging, affecting display quality and lifespan.
Innovation Solution
A driving apparatus and method utilizing thermal and optical sensors, along with a processor, to detect temperature and brightness/color differences, and calibrate initial thermal compensation tables to adjust working currents of light emitting diodes, compensating for decay and maintaining brightness and color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light emitting diodes operate continuously or use local dimming technology, then display quality and energy efficiency are improved, but brightness and color decay occur due to temperature rise and aging
Solution Approach 1:
The patent implements a feedback control system where optical sensors detect the actual brightness and color output of the backlight module, and thermal sensors monitor the temperature of light emitting diodes. This detection information is fed back to the processor, which adjusts the working currents of the light emitting diodes in real-time to compensate for brightness and color decay caused by temperature rise and aging, thereby maintaining stable display quality.
Solution Approach 2:
The patent changes the operating parameters (working currents) of the light emitting diodes based on detected temperature and brightness/color values. By dynamically adjusting these parameters through compensation tables stored in memory, the system compensates for the effects of temperature rise and aging on brightness and color output, resolving the contradiction between maintaining display quality and preventing decay.
2Illumination intensity
If thermal compensation is applied to maintain brightness and color, then display quality is improved, but device complexity increases due to additional sensors and processing
Solution Approach 1:
The patent makes the processor perform multiple functions: it processes display signals, manages thermal compensation calculations, stores and retrieves compensation tables, and controls the working currents of light emitting diodes. The memory device also serves dual purposes by storing both display content and thermal compensation data. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent introduces thermal compensation tables as an intermediary data structure that pre-calculates the relationship between temperature, working currents, and brightness/color output. These tables act as a mediator between the raw sensor data and the final control decisions, simplifying the processing logic required in real-time operation and reducing the computational complexity of the system.
3Duration of action of stationary object
If calibration function is enabled to compensate for aging, then long-term display quality is maintained, but initial setup time and processing overhead increase
Solution Approach 1:
The patent performs calibration operations in advance to generate thermal compensation tables that account for aging effects. These pre-calibrated compensation tables are stored in memory for future use. During normal operation, the system simply retrieves and applies the pre-computed compensation data, avoiding the need for time-consuming real-time calibration and reducing the perceived setup time for end users.
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 effectively compensates for brightness and color decay, maintaining uniformity and extending the lifespan of backlight modules by using thermal and optical feedback control.
Implementation Method 1
The at least one thermal sensor is for detecting a working temperature of the light emitting diodes
Implementation Method 2
The optical sensor is for detecting brightness and color of the backlight module
Implementation Method 3
a plurality of light emitting diodes have been widely used as such light source
Implementation Method 4
When the backlight module is in operation, energy received by the light emitting diodes of the backlight module would be converted into heat
Data Source
AI summary
A driving apparatus and a driving method of a backlight module are provided. The backlight module includes multiple LEDs. The driving apparatus includes at least one thermal sensor, an optical sensor, and a processor. The thermal sensor is for detecting a working temperature of the LEDs. The optical sensor is for detecting brightness and color of the backlight module after a calibration function is enabled, to obtain difference values of the detected brightness and color with respect to predetermined brightness and color. The processor is for providing at least one initial thermal compensation table, to determine working currents of the LEDs associated with the working temperature. The processor further is for calibrating a content of the initial thermal compensation table corresponding with a current working temperature of the LEDs and storing the calibrated thermal compensation table as the initial thermal compensation table after the calibration function is enabled.