Backlight Phase Control to Reduce Touchscreen EMI Interference
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Solution Overview
Problem
As display products increase in size and brightness, backlight drive devices generate interference frequencies that can affect touch screen operation and worsen EMI performance, requiring costly firmware adjustments or hardware additions.
Innovation Solution
A backlight control method and system that adjusts the phase of the backlight source using a phase adjustment signal within the backlight control signal, allowing for direct phase control without additional hardware, and includes a master control board to analyze and generate backlight control signals based on audio and video inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If more backlight drive devices are used to increase display size and brightness, then display performance is improved, but interference to touch screens and EMI performance deteriorates
Solution Approach 1:
The patent changes the operating parameters of the backlight drive devices by adjusting their phase. The master control board generates phase adjustment signals that modify the timing and synchronization of backlight drive signals, thereby changing the frequency characteristics of the emitted electromagnetic interference. This parameter adjustment reduces the overlap between backlight interference frequencies and touch screen operating frequencies, resolving the contradiction between maintaining high brightness and reducing interference.
2Reliability
If firmware adjustments or hardware additions are made to reduce interference, then EMI performance is improved, but device complexity and cost increase
Solution Approach 1:
The master control board is designed to perform multiple functions: it controls the backlight drive devices, generates phase adjustment signals, and coordinates with the touch screen controller. By making the master control board multi-functional, the patent avoids adding separate dedicated hardware for interference reduction and eliminates the need for complex firmware modifications, thereby improving EMI performance without increasing device complexity.
Solution Approach 2:
The system implements self-service by having the master control board automatically generate and apply phase adjustment signals based on the operating conditions. The control board monitors the system state and autonomously adjusts the backlight phase to minimize interference, eliminating the need for external intervention, additional control hardware, or complex firmware updates.
3Ease of operation
If phase adjustment is implemented through traditional methods, then backlight phase control is achieved, but additional hardware and implementation complexity are required
Solution Approach 1:
The patent merges the phase adjustment functionality into the existing backlight control system. The master control board integrates the generation and application of phase adjustment signals within its existing backlight control operations. By combining these functions rather than implementing them as separate systems, the patent achieves easy phase control without adding hardware complexity.
Data Source
AI summary
Provided are a backlight control method and system, a display device and a readable storage medium. The backlight control method includes: obtaining a backlight control signal, where the backlight control signal includes a mode signal and a data signal (21); obtaining the mode signal in the backlight control signal, where the mode signal includes a phase adjustment signal or a local dimming signal (22); in response to that the mode signal is the phase adjustment signal, writing the data signal corresponding to the mode signal into a light source drive module, such that the light source drive module adjusts a phase of a backlight source based on the data signal (23). By adding the phase adjustment signal to the backlight control signal, a backlight refresh phase may be directly adjusted by a front end device, without adding hardware, bringing conveniences and speediness.