Power Regulating Circuit for LCD Brightness and Power Optimization
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Solution Overview
Problem
Liquid crystal display devices have high energy consumption due to inefficient power management in light emitting units, despite adjustments in brightness, leading to increased power consumption even at disclosed brightness levels.
Innovation Solution
A power regulating circuit comprising a brightness sensing unit, power consumption detecting unit, control chip, and voltage regulating unit that adjusts the supply voltage amplitude and duty ratio to minimize power consumption while maintaining brightness, using a multiplying unit, photocoupler, and thin film transistor to optimize power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the brightness of the light emitting unit is adjusted to the required level, then the illumination requirement is met, but the power consumption remains excessively high
Solution Approach 1:
The patent applies PWM (Pulse Width Modulation) technology to dynamically adjust the duty cycle of the supply voltage to the light emitting unit. By varying the duty cycle rather than simply reducing voltage amplitude, the system maintains optimal current characteristics while controlling brightness, thereby resolving the contradiction between achieving required illumination and minimizing power consumption
Solution Approach 2:
The patent changes the parameter being controlled from voltage amplitude to duty cycle. The control chip adjusts the duty cycle of the supply voltage to regulate brightness, while the amplitude remains optimized for efficient operation. This parameter transformation allows independent optimization of both brightness control and power consumption
2Illumination intensity
If traditional brightness control methods are used, then the light emitting unit reaches the required brightness, but energy efficiency is poor
Solution Approach 1:
The patent incorporates a feedback mechanism where the control chip continuously monitors the state of the light emitting unit and adjusts the PWM duty cycle accordingly. This closed-loop control ensures that the minimum necessary energy is consumed to achieve the required brightness level, preventing energy waste while maintaining optimal illumination
Solution Approach 2:
The patent uses periodic PWM signaling to control the light emitting unit. Instead of continuous DC voltage application, the system applies periodic pulses with variable duty cycles, allowing the unit to operate at peak efficiency during active periods while consuming minimal power during off periods, thereby reducing overall energy loss
Data Source
AI summary
The present invention provides a power regulating circuit and a liquid crystal display device. The light emitting unit is applied with a first supply voltage for emitting light, and the power regulating circuit comprises a brightness sensing unit, a power consumption detecting unit, a control chip and a voltage regulating unit, and the brightness sensing unit senses a brightness, and the power consumption detecting unit detects a power consumption, which is a first power consumption, and the control chip compares the first power consumption with a minimum power consumption of a current brightness of the light emitting unit, and as a difference of the first power consumption and the minimum power consumption is larger than a preset threshold value, the control chip controls the voltage regulating unit to decrease an amplitude of the first supply voltage and to increase a duty ratio of the first supply voltage.