Stationary Elliptical Mirror for Compact Stereoscopic Display

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Solution Overview

Problem

Conventional image display apparatuses for stereoscopic images require a movable Fresnel mirror, leading to complexity, increased cost, and a larger footprint due to the need for lateral arrangement of light sources, which complicates the construction and increases weight.

Innovation Solution

An image display apparatus featuring a stationary elliptical mirror with a symmetrical reflecting surface and light sources positioned between the mirror's focus and the observer's eyes, allowing for a compact design and reduced cost by eliminating the need for a movable mirror and optimizing light source placement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a movable Fresnel mirror is used to distribute images to both eyes, then stereoscopic image display is achieved, but apparatus complexity and cost increase

Engineering Contradiction:
Improvestereoscopic image display capabilityVSAvoidapparatus complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts the movable portion (Fresnel mirror) from the system and replaces it with a stationary elliptical mirror. The essential function of image distribution is maintained through the optical properties of the stationary mirror and strategic light source placement, eliminating the need for mechanical movement while preserving stereoscopic display capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical system (movable Fresnel mirror) with an optical system (stationary elliptical mirror combined with specific light source arrangement). The mechanical movement required for image distribution is substituted by the optical path design, where light from two sources reflects off the elliptical mirror to reach the observer's eyes, achieving the same functional outcome without mechanical complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If light sources are arranged on opposite side surfaces of the reflection unit, then image distribution to both eyes is achieved, but apparatus size increases

Engineering Contradiction:
Improveimage distribution capabilityVSAvoidapparatus footprint
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The invention merges the light source arrangement with the elliptical mirror structure. Instead of placing light sources on opposite side surfaces which would require lateral space, the light sources are positioned adjacent to one focus of the elliptical mirror, utilizing the mirror's geometric properties to distribute images to both eyes within a compact footprint.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention changes the spatial arrangement from a lateral distribution (opposite side surfaces) to a focal point-based distribution. By positioning light sources relative to the focus of the elliptical mirror and using the mirror's reflective properties, the system achieves image distribution to both eyes without requiring large lateral space, effectively utilizing the focal geometry to compress the apparatus footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If multiple elliptical mirrors are laminated, then image distribution to both eyes is achieved, but apparatus weight increases

Engineering Contradiction:
Improveimage distribution capabilityVSAvoidapparatus weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The invention extracts the requirement for multiple laminated elliptical mirrors and replaces it with a single stationary elliptical mirror. By strategically positioning two light sources adjacent to one focus of this single mirror, the system achieves the same image distribution function that previously required multiple mirrors, thereby reducing the total weight of the apparatus.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If a movable Fresnel mirror is used, then stereoscopic display is achieved, but apparatus cost increases

Engineering Contradiction:
Improvestereoscopic display capabilityVSAvoidapparatus cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention extracts the movable portion (Fresnel mirror) from the system, eliminating the need for mechanical drive mechanisms, precision alignment systems, and complex control electronics. This simplification directly reduces manufacturing costs while maintaining the essential stereoscopic display function through a stationary elliptical mirror and coordinated light source arrangement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical system (movable Fresnel mirror with actuators and control systems) with a simpler optical system (stationary elliptical mirror with fixed light sources). This substitution eliminates mechanical components that drive up manufacturing costs, while the optical design maintains the ability to distribute images to both eyes for stereoscopic display.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 achieves a reduction in size and cost while maintaining effective stereoscopic image display capabilities, with the elliptical mirror's symmetrical design enabling efficient use of light sources and reducing the apparatus's width and weight.

Implementation Method 1

a reflection unit disposed at a back side of the transmission type display panel, and including an elliptical mirror which corresponds to part of an arc of an ellipse and has a reflecting surface shaped symmetrical across a center line in plan view

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2388636B1Image display apparatus
Publication Date: 2019.05.01 EIZO CORP
  • EP2388636B1 patent drawingFigure 1
  • EP2388636B1 patent drawingFigure 2
  • EP2388636B1 patent drawingFigure 3

AI summary

The stereoscopic image display apparatus of this invention includes an upper light source unit 29 having a pair of light sources 33 and 35 and a lower light source unit, which are arranged between a reflection unit 17 with an elliptical mirror 15 having one focus fl on the side of a reflecting surface 19, and a transmission type liquid crystal display panel 5. Thus, the apparatus has a reduced width. Moreover, the elliptical mirror 15 is the stationary type, and the reflecting surface 19 employed is shaped symmetrical in plan view. This allows the respective light sources to use the common elliptical mirror 15. Therefore, the stereoscopic image display apparatus realizes a reduction in size and a reduction in apparatus cost.