Near-Eye Display Optics: Polarization and Curved-Mirror Ghosting Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current near-eye display devices suffer from ghosting issues due to light being refracted and reflected multiple times on flat glass coated with a transflective film, affecting the visual experience.
Innovation Solution
A near-eye display device design incorporating a display screen, imaging lens, flat plate, phase retardation layer, polarization beam-splitting layer, polarizing layer, and curved mirror, which utilize specific polarization and reflection properties to separate and direct light paths to eliminate ghosting and stray light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If a flat glass coated with transflective film is used in the near-eye display optical system, then the system can achieve small size and light weight, but light is refracted and reflected multiple times causing ghosting problems that affect visual effect
Solution Approach 1:
The patent extracts and removes the flat glass component from the optical system, replacing it with a curved mirror. This eliminates the multiple refraction and reflection surfaces that cause ghosting, while the curved mirror provides the necessary light redirection without the harmful optical effects.
Solution Approach 2:
Instead of using a flat glass with transflective coating to redirect light, the patent inverts the approach by using a curved mirror that naturally reflects and redirects light through its geometry. This inversion of the optical element and its function eliminates the ghosting problem while maintaining the desired light redirection capability.
2Volume of moving object
If a flat glass with transflective film is used to redirect light, then the optical system remains compact, but multiple reflections on upper and lower surfaces create imaging errors and ghosting
Solution Approach 1:
The patent removes the flat glass element that causes multiple reflections and imaging errors, replacing it with a curved mirror that provides single-surface light redirection. This maintains the compact volume while significantly improving imaging quality by eliminating the source of optical errors.
Solution Approach 2:
The patent changes the geometric parameter of the optical element from flat to curved, transforming it from a plane surface that causes multiple reflections to a curved surface that provides controlled single-surface reflection. This parameter change eliminates imaging errors while maintaining system compactness.
3Length of stationary object
If multiple reflections occur on flat glass surfaces, then the optical path is extended, but ghosting images are formed and visual effect is degraded
Solution Approach 1:
The patent inverts the optical approach by using a curved mirror that redirects light through a single reflection surface rather than multiple reflections on flat surfaces. This maintains the necessary optical path length for image formation while eliminating the ghosting images that degrade visual effect.
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 proposed design effectively suppresses ghosting and minimizes stray light interference, enhancing the visual experience by optimizing image clarity and ambient light visibility.
Implementation Method 1
a polarization beam-splitting layer, located between the phase retardation layer and the flat plate; where the polarization beam-splitting layer is configured to transmit first linearly polarized light and reflect second linearly polarized light having a polarization direction perpendicular to that of the first linearly polarized light
Implementation Method 2
a polarizing layer, located between the polarization beam-splitting layer and the flat plate, where the polarizing layer is configured to transmit the first linearly polarized light and absorb the second linearly polarized light
Implementation Method 3
a curved mirror, located on a reflection light path of the polarization beam-splitting layer and located on one side, facing away from the flat plate, of the phase retardation layer; where the curved mirror is configured to reflect reflected light of the polarization beam-splitting layer to a position of human eyes and transmit ambient light
Implementation Method 4
a phase retardation layer, located on one side, facing the imaging lens, of the flat plate
Data Source
AI summary
A near-eye display device, including: a display screen (1) used for image display; an imaging lens (2) located at a light emission side of the display screen (1) and used for imaging a displayed image of the display screen (1); a flat plate (3) located on the side of the imaging lens (2) facing away from the display screen (1) and obliquely arranged relative to the optical axis of the imaging lens (2); a phase retardation layer (4) located on the side of the flat plate (3) facing the imaging lens (2); a polarization beam-splitting layer (5) located between the phase retardation layer (4) and the flat plate (3); a polarizing layer (6) located between the polarization splitting layer (5) and the flat plate (3); and a curved mirror (7).