Multiplane Light Diffuser for LED Backlight Uniformity

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Solution Overview

Problem

Conventional backlighting units for LCD displays using cold cathode fluorescent lamps (CCFLs) require high voltages and generate excessive heat, making them difficult to dissipate and inefficient for uniform lighting.

Innovation Solution

A solid state lighting device with multiple solid state light emitters and a multiplane light diffuser system, comprising a diffuser plate and a diffuser sheet positioned at specific distances to emit and diffuse light uniformly, replacing CCFLs with LEDs and using a structured refractive diffuser to enhance light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If cold cathode fluorescent lamps (CCFLs) are used for backlighting, then sufficient illumination intensity is achieved, but high voltage requirements and excessive heat generation occur

Engineering Contradiction:

Improvebacklighting illuminationVSAvoidheat generation and high voltage requirements

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the CCFL-based optical system with a solid-state LED lighting system. This substitution eliminates the need for high voltage operation and significantly reduces heat generation while maintaining adequate backlighting illumination intensity through the use of multiple LED emitters arranged in a matrix configuration.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The backlighting system is divided into multiple discrete LED emitters arranged in a matrix, replacing the single or few CCFL tubes. This segmentation allows for distributed light emission across the display area, improving uniformity while reducing the heat concentration and voltage requirements associated with individual CCFL operation.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If CCFLs are used in a reflective enclosure, then uniform backlighting is achieved, but heat dissipation becomes problematic

Engineering Contradiction:

Improveuniformity of backlightingVSAvoidheat dissipation

Core Design Contradiction:

Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent replaces the CCFL-based reflective enclosure system with solid-state LED emitters that inherently produce less heat. The LED matrix provides uniform light distribution through its spatial arrangement and the use of diffusion elements, eliminating the need for highly reflective enclosures that trap heat while maintaining backlighting uniformity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from a two-dimensional CCFL tube arrangement to a three-dimensional LED matrix configuration with multiple emission layers. This dimensional expansion allows light to be emitted from multiple planes, improving uniformity across the display surface while distributing heat generation across numerous low-power LED elements rather than concentrating it in a reflective enclosure.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If multiple diffusion planes are used to improve light uniformity, then light distribution is enhanced, but device complexity increases

Engineering Contradiction:

Improvelight uniformityVSAvoiddiffuser structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent employs multiple diffusion planes positioned at different distances from the LED emitter matrix, creating a three-dimensional light diffusion architecture. This multiplanar approach distributes light uniformly across the display area by scattering photons through multiple interfaces, achieving superior uniformity without requiring complex mechanical or optical components within each individual diffusion layer.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 provides a more efficient and heat-free backlighting system with improved light uniformity and reduced power requirements, enhancing the performance and reliability of LCD displays.

Implementation Method 1

a multiplane light diffuser including a first diffusion plane and a second diffusion plane that are separated by a gap. The multiplane light diffuser includes a first side that is configured to receive the light emitted from the solid state light emitters and a second side that is configured to transmit diffused light.

Methodology Applied

Scientific EffectLight diffusion: Scattering

Data Source

PatentUS8177382B2Apparatus and methods for multiplanar optical diffusers and display panels for using the same

Publication Date: 2012.05.15 BRIGHTPLUS VENTURES LLC

AI summary

Provided are solid state lighting devices that include multiple solid state light emitters that are configured to emit light and a multiplane light diffuser including a first diffusion plane and a second diffusion plane that are separated by a gap, the multiplane light diffuser including first side that is configured to receive the light emitted from the solid state light emitters and a second side that is configured to transmit diffused light.