Backlight Lamp Control for LCD Power and Brightness

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Solution Overview

Problem

The existing liquid crystal display devices using orthogonal-type backlight units face increased power consumption and reduced brightness due to the scanning driving method, which affects image quality and lamp reliability.

Innovation Solution

A system that includes a timing controller for generating lamp control signals, an inverter for controlling light-on and light-off of the lamps, and a lamp controller that maintains power supply to the lamps regardless of light-on time, using an oscillator to generate alternating current and a transformer to convert it into high voltage, while limiting current to prevent excessive power consumption and ensure consistent brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If scanning driving method is used to reduce power consumption, then power consumption is reduced, but brightness becomes inconsistent and image quality deteriorates

Engineering Contradiction:

Improvepower consumptionVSAvoidbrightness consistency

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent applies periodic scanning driving to sequentially activate different lamps in the backlight unit. By dividing the backlight into multiple zones and activating them in periodic cycles rather than continuously, power consumption is reduced while maintaining acceptable brightness levels through temporal distribution of light output.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent dynamically adjusts the driving parameters of the lamps, including duty cycle and intensity, to optimize between power consumption and brightness consistency. By changing operational parameters based on scanning patterns, the system achieves energy efficiency while minimizing brightness variation across different temporal zones.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If scanning driving method is used, then power consumption is reduced, but lamp reliability decreases due to excessive current

Engineering Contradiction:

Improvepower consumptionVSAvoidlamp reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent incorporates feedback control mechanisms that monitor lamp operation and adjust driving current accordingly. By detecting lamp status and power consumption levels, the system dynamically regulates current amplitude to prevent excessive current conditions that would compromise lamp reliability, while still achieving power reduction through scanning operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent employs dynamic current regulation that adapts the driving current amplitude based on real-time operating conditions. Rather than using fixed high current that damages lamps, the system dynamically adjusts current levels to match scanning patterns and load requirements, reducing stress on lamps while maintaining power efficiency.

Inventive Principle:

Principle #15Dynamics

3Illumination intensity

If multiple lamps are arranged in orthogonal-type backlight unit, then brightness is improved, but power consumption increases

Engineering Contradiction:

ImprovebrightnessVSAvoidpower consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent divides the backlight unit into multiple independent lamp zones arranged in orthogonal configuration. By segmenting the backlight into controllable sections rather than using a single continuous light source, the system can activate only necessary zones, reducing overall power consumption while maintaining high brightness in active regions through concentrated light output.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent activates only a subset of available lamps at any given time through scanning operation, rather than running all lamps continuously. This partial action approach provides sufficient brightness for display requirements while avoiding the excessive power consumption that would result from continuous full-array operation, achieving optimal balance between illumination and energy usage.

Inventive Principle:

Principle #16Partial or excessive action

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

This solution reduces power consumption, maintains consistent brightness, and enhances lamp reliability by adjusting the light-on time and current amplitude, preventing degradation of image quality and extending lamp life.

Implementation Method 1

an inverter for converting direct current power applied from an exterior into a high voltage alternating current

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a lamp for emitting light in response to receiving power

Methodology Applied

Scientific EffectGas discharge luminescence: Electric Glow Discharge

Data Source

PatentUS7852312B2System for controlling driving lamp of backlight unit

Publication Date: 2010.12.14 LG DISPLAY CO LTD

AI summary

A liquid crystal display device including a liquid crystal display panel, a lamp for emitting light to the a liquid crystal display panel, a timing controller for generating a lamp control signal to control a light-on time of the lamp, and an inverter for controlling a light-on and a light-off of the lamp according to the lamp control signal while limiting current and maintaining power supplied to the lamp regardless of the light-on time for the lamp.