Aspheric Lens Merging Optical Functions for Compact Projection

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Solution Overview

Problem

Conventional image projection apparatuses face challenges in achieving a compact structure and high durability while maintaining full HD picture quality, as they require a large number of glass lenses, which increases the system size and complicates the implementation of ultra short throw ratios and stereoscopic images.

Innovation Solution

The use of aspheric lenses formed from glass molding material with polarization characteristics reduces the number of lenses needed, eliminating the need for additional lenses to produce stereoscopic images and allowing for a more compact design by controlling the refraction degree of the light bundle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a large number of glass lenses are used to achieve full HD picture quality, then image quality is improved, but the system size and device complexity increase

Engineering Contradiction:
Improvepicture qualityVSAvoidnumber of lenses
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple lens functions are merged into a single aspheric lens. The aspheric lens integrates the optical functions that would traditionally require multiple spherical lenses, thereby reducing the total number of lenses while maintaining full HD picture quality. This merging approach directly addresses the contradiction by consolidating optical elements without sacrificing image quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention changes the geometric parameters of the lens from traditional spherical surfaces to aspheric surfaces. By modifying the lens shape parameters and using glass molding material with specific polarization characteristics, the aspheric lens achieves superior optical performance with fewer elements, resolving the contradiction between image quality and device complexity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If additional lenses are added to implement stereoscopic image output, then stereoscopic functionality is improved, but the system size increases

Engineering Contradiction:
Improvestereoscopic image capabilityVSAvoidsystem size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The aspheric lens is designed with polarization characteristics that enable it to perform multiple functions: it serves as both the primary focusing lens and the stereoscopic image output element. This multi-functionality eliminates the need for separate additional lenses for stereoscopic output, thereby maintaining compact system size while achieving stereoscopic capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The stereoscopic functionality is merged into the aspheric lens itself through its polarization characteristics. Instead of adding separate stereoscopic output lenses, the invention integrates this capability into the existing aspheric lens structure, reducing system size while maintaining adaptability for stereoscopic imaging.

Inventive Principle:
Principle #5Merging (Combining)

3Area of stationary object

If the number of lenses is increased to project a large image, then image projection capability is improved, but the entire size of the optical system increases

Engineering Contradiction:
Improveprojected image sizeVSAvoidoptical system size
Core Design Contradiction:
Area of stationary objectVSVolume of moving object

Solution Approach 1:

By changing from spherical lenses to aspheric lenses with optimized surface parameters, the invention achieves higher light gathering efficiency and better focusing capability. This parameter change allows for effective large image projection with fewer lenses, thereby preventing the optical system size from increasing proportionally with the projected image size.

Inventive Principle:
Principle #35Parameter changes

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 configuration enables a compact, durable image projection apparatus capable of projecting high-quality, full HD images, including stereoscopic content, without the need for additional lenses, thereby reducing the overall system size and enhancing image projection capabilities.

Implementation Method 1

a first aspheric lens 151 having a first refraction surface 151a and a second refraction surface 151b, and a second aspheric lens 152 having a first refraction surface 152a and a second refraction surface 152b, in the projection system 140

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

since a three-dimensional (3D) stereoscopic image is output by using the aspheric lenses formed of a glass molding material and having a polarization characteristic

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP2950141B1Image projection apparatus
Publication Date: 2023.08.09 LG ELECTRONICS INC
  • EP2950141B1 patent drawingFigure 1~2a
  • EP2950141B1 patent drawingFigure 2b~3
  • EP2950141B1 patent drawingFigure 4~5

AI summary

The present invention provides an image projection apparatus comprising a light source for emitting a light bundle, a display element forming an image by using the light bundle, and a projection system having: a lens unit refracting the light bundle so as to magnify and project the image and including first and second aspheric lenses, which are spaced from each other and change the refraction of the light bundle, and at least one spherical lens disposed between the first and second aspheric lenses; and a mirror for reflecting, toward the outside, the light bundle delivered by the lens unit.