Optical Lens Curved Third Surface Uniform Backlight Control

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Solution Overview

Problem

Conventional display devices face challenges in uniformly distributing light from backlight units, leading to uneven brightness and image quality issues due to ineffective light path control, resulting in dark areas and hot spots.

Innovation Solution

An optical lens with a specific shape, including a first surface with a circular cross-sectional shape, a second surface with a concave portion, and a third surface connecting both, is used to control the light path by diffusing and refracting light emitted from the light source, ensuring uniform light distribution across the display panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional backlight units are used without specialized optical lenses, then the device structure remains simple, but light distribution becomes uneven causing dark areas and hot spots

Engineering Contradiction:
Improveuniformity of brightnessVSAvoidoptical lens structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent employs a lens with a curved third surface that connects the first and second surfaces. This curvature is specifically designed to refract light rays in a controlled manner, directing them uniformly across the display panel. The curved surface geometry transforms the point-source light emission into a uniform area illumination, resolving the contradiction between structural simplicity and lighting uniformity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The lens incorporates different surface characteristics in different regions: the first surface has a circular cross-sectional shape, the second surface has a concave portion, and the third surface connects them with specific curvature. Each region's geometry is optimized for its local function in light control, allowing the single lens component to achieve uniform light distribution without complex multi-component systems.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If light path control is not implemented, then the optical system remains simple, but image quality deteriorates due to light and shade differences

Engineering Contradiction:
Improveimage qualityVSAvoidlight path control mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The lens acts as an intermediary optical element between the light source and the display panel. Its specifically shaped third surface serves as a mediating structure that refracts and redirects light rays, transforming the raw light emission into a controlled, uniform illumination pattern that enhances image quality without requiring complex active control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If a simple lens shape is used, then manufacturing is easier, but hot spots and uneven brightness occur

Engineering Contradiction:
Improvelens fabricationVSAvoidbrightness uniformity
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The lens design utilizes a curved third surface with specific geometric properties that can be manufactured using standard optical molding or grinding techniques. The curvature profile is optimized to achieve uniform light distribution while remaining compatible with conventional lens manufacturing processes, balancing ease of manufacture with optical performance.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 optical lens effectively controls the light path, minimizing light and shade differences and preventing hot spots, thereby enhancing the image quality and uniformity of brightness across the display panel.

Implementation Method 1

An optical lens with a specific shape, including a first surface with a circular cross-sectional shape, a second surface with a concave portion, and a third surface connecting both, is used to control the light path by diffusing and refracting light emitted from the light source

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

An optical lens with a specific shape, including a first surface with a circular cross-sectional shape, a second surface with a concave portion, and a third surface connecting both, is used to control the light path by diffusing and refracting light emitted from the light source

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3040755B1Optical lens and display device including the same
Publication Date: 2024.11.13 LG ELECTRONICS INC
  • EP3040755B1 patent drawingFigure 1
  • EP3040755B1 patent drawingFigure 2
  • EP3040755B1 patent drawingFigure 3

AI summary

An optical lens and a display device including the same are provided. An optical lens includes a first surface having a circular cross-sectional shape, a second surface opposite to the first surface, and a third surface configured to connect the first surface and the second surface. The third surface includes a straight surface extending from a boundary of the first surface and a first curved surface extending from the straight surface to the second surface. The straight surface and the first curved surface extending in a path between the first surface and the second surface. The second surface includes a concave recess recessing in a direction of the first surface and the concave recess includes a second curved surface. Light that has passed through the second concave surface changes a path as the light passes through the first curved surface such that light path can be effectively controlled.