Light-Guide Display Optics With LC Dimming for Bright Surroundings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Head-mounted displays using light guide members and holographic optical elements face reduced visibility of images due to high external light intensity, which affects user experience.
Innovation Solution
A display device comprising a transparent substrate, a display element emitting circularly polarized light, first and second optical elements for diffraction, a dimming element with guest-host liquid crystal, and a retardation film to manage light intensity, ensuring optimal image visibility in varying light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light guide member with holographic optical elements is used to display images, then image display functionality is achieved, but image visibility is reduced under high external light intensity
Solution Approach 1:
The patent applies a liquid crystal dimming element that can dynamically change its light transmission properties based on external light conditions. The liquid crystal material transitions between different optical states (transparent and opaque) in response to applied voltage, enabling real-time adaptation to varying ambient light levels and maintaining image visibility across different environments.
Solution Approach 2:
The patent changes the optical parameters of the light guide member by introducing a liquid crystal dimming element whose transmission characteristics can be controlled. By adjusting the liquid crystal's optical state through voltage control, the system modifies the light transmission parameter to compensate for high external light intensity, thereby maintaining adequate image visibility.
2Adaptability or versatility
If the light guide member allows external light transmission for background observation, then transparency is maintained, but image clarity is reduced in bright environments
Solution Approach 1:
The liquid crystal dimming element provides dynamic control over light transmission, allowing the system to switch between transparent state (for background observation) and dimmed state (for image clarity). This dynamic adaptability enables the light guide member to optimize its performance based on whether the user needs to observe the background or view the displayed image clearly.
Solution Approach 2:
The light guide member is designed to perform multiple functions: it can simultaneously serve as an image display medium and a transparent window for background observation. The liquid crystal dimming element enables the same component to adapt its function based on external conditions, providing both AR display capability and transparent display capability when needed.
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 device maintains image visibility by adjusting light transmission based on external light conditions, preventing reduction in image clarity in bright environments and allowing background observation in dark environments.
Implementation Method 1
a display element which faces the first main surface and is configured to emit display light which is circularly polarized light toward the transparent substrate
Implementation Method 2
a first optical element which faces the display element via the transparent substrate, is provided on the second main surface and is configured to diffract display light which passed through the transparent substrate
Implementation Method 3
a second optical element which is spaced apart from the first optical element, is provided on the second main surface and is configured to diffract display light which propagated inside the transparent substrate
Implementation Method 4
When a voltage is applied to the liquid crystal layer, the guest-host liquid crystal forms an absorption axis parallel to the alignment treatment direction
Implementation Method 5
a retardation film provided between the transparent substrate and the dimming element
Data Source
AI summary
According to one embodiment, a display device includes a transparent substrate, a display element configured to emit display light which is circularly polarized light toward the transparent substrate, a first optical element which faces the display element via the transparent substrate and is configured to diffract display light which passed through the transparent substrate, a second optical element which is spaced apart from the first optical element and is configured to diffract display light which propagated inside the transparent substrate, a dimming element which faces the second optical element via the transparent substrate and includes a guest-host liquid crystal, and a retardation film provided between the transparent substrate and the dimming element.