Backlight Luminance Control Signal Generation Method
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Solution Overview
Problem
Conventional backlight luminance control methods face issues when dealing with multiple factors, leading to defects such as loss of duty and unintended turn-off of the backlight due to the superimposition of PWM signals.
Innovation Solution
A display device with a signal generating section that receives and processes multiple parameters to generate a luminance control signal, preventing the superimposition of PWM signals and ensuring proper backlight control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple PWM signals are superimposed to control backlight luminance based on multiple factors, then the backlight can be controlled according to both environment and content, but loss of duty occurs causing the backlight to turn off unintentionally
Solution Approach 1:
The patent applies preliminary action by calculating the duty ratio of the synthesized PWM signal in advance, before generating the actual control signal. The control signal generating unit computes the duty ratio based on multiple input parameters (environmental luminance, content characteristics, etc.), then generates a single PWM signal with the pre-calculated duty ratio. This prevents the superimposition problem because the duty ratio is determined beforehand rather than through real-time signal addition, ensuring the backlight receives a valid control signal that won't cause unintended turn-off.
2Adaptability or versatility
If PWM signals from different control blocks are synthesized by superimposition, then multiple control factors can be integrated, but the synthesis process causes loss of duty and control defects
Solution Approach 1:
The patent extracts the essential control parameter (duty ratio) from multiple PWM signals before synthesis. Instead of superimposing multiple PWM signals directly, the control signal generating unit extracts the duty ratio values from each control block's PWM signal, synthesizes these extracted duty ratio values to determine the final duty ratio, then generates a single PWM signal with this synthesized duty ratio. This extraction approach simplifies the synthesis process by working with scalar duty ratio values rather than complex time-varying PWM waveforms.
3Use of energy by stationary object
If the backlight is controlled to be turned on or off based on illuminance levels, then power consumption can be reduced, but the backlight may turn off when it should remain on based on other factors
Solution Approach 1:
The patent applies parameter changes by using multiple parameters to determine the final duty ratio instead of relying on a single illuminance parameter. The control signal generating unit receives multiple parameters including environmental illuminance information, content characteristics, and other control factors. It synthesizes these multiple parameters to calculate the final duty ratio, ensuring that the backlight luminance is adjusted based on a comprehensive evaluation of all factors rather than being overridden by a single parameter, thus maintaining both energy efficiency and control flexibility.
Data Source
AI summary
Provided is a display device capable of properly controlling a luminance of a backlight on the basis of a plurality of factors. The display device is a display device (10) which includes a BL luminance control signal generating block (44) for generating a BL luminance control signal for controlling a luminance of a backlight unit (30). The BL luminance control signal generating block (44) (i) receives a plurality of BL luminance parameters regarding the luminance of the backlight unit (30), (ii) carries out a calculation process with respect to the plurality of BL luminance parameters and (iii) generates the BL luminance control signal on the basis of a result of the calculation process.