Optical Waveguide Light Leakage Prevention Element
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current augmented reality (AR) devices with optical waveguide systems based on diffraction gratings suffer from high light leakage rates, leading to privacy issues and low light efficiency, which results in low brightness and high power consumption.
Innovation Solution
The optical waveguide system incorporates a light-leakage prevention element on the side opposite to the grating, which reduces light emission by reflecting, diffracting, or absorbing light, thereby minimizing leakage and improving light energy utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If gratings with extremely low diffraction efficiency are used to ensure uniformity and transmittance of the exit pupil, then the uniformity of the exit pupil is improved, but the light efficiency of the optical waveguide system becomes very low, resulting in low brightness and high power consumption
Solution Approach 1:
The patent segments the optical waveguide into two distinct sides: a first side face with a grating for light coupling and an exit pupil, and a second side face with a light-leakage prevention element for preventing light leakage. This segmentation allows each side to be optimized independently - the first side for uniformity and the second side for preventing energy loss through leakage, thereby resolving the contradiction between exit pupil uniformity and light efficiency
Solution Approach 2:
The patent applies different functional properties to different locations of the optical waveguide. The first side face is designed with grating structures optimized for uniform light distribution, while the second side face is equipped with light-leakage prevention elements. This local differentiation allows each region to perform its specific function optimally without compromising the other, thus improving both uniformity and light efficiency simultaneously
2Stability of the object's composition
If gratings with extremely low diffraction efficiency are used to ensure uniformity and transmittance of the exit pupil, then the uniformity of the exit pupil is improved, but the brightness of the AR device becomes low
Solution Approach 1:
By segmenting the optical waveguide into two functional sides, the patent allows the first side to maintain low diffraction efficiency for uniformity while the second side prevents light leakage that would otherwise reduce brightness. This segmentation ensures that light is not wasted through leakage, thereby improving overall brightness without compromising uniformity
Solution Approach 2:
The patent converts the potentially harmful effect of light leakage into a beneficial outcome by using light-leakage prevention elements. These elements capture light that would otherwise be lost and redirect it back into the optical waveguide, transforming energy loss into useful light that contributes to brightness, thus resolving the contradiction between uniformity and brightness
3Stability of the object's composition
If gratings with extremely low diffraction efficiency are used to ensure uniformity and transmittance of the exit pupil, then the uniformity of the exit pupil is improved, but the power consumption of the AR device becomes high
Solution Approach 1:
The segmentation of the optical waveguide into two functional sides allows the system to maintain low diffraction efficiency for uniformity while preventing energy loss through leakage on the second side. This reduces the amount of energy that needs to be supplied to achieve the desired brightness level, thereby lowering power consumption without compromising uniformity
Solution Approach 2:
By converting light leakage from a harmful energy loss into a beneficial resource through the light-leakage prevention elements, the system recovers energy that would otherwise be wasted. This recovered energy contributes to the overall light output, reducing the power consumption required to maintain the desired brightness and uniformity levels
4Device complexity
If conventional optical waveguide systems are used, then the device structure is simple, but virtual image light leaks to the external environment, causing privacy leakage
Solution Approach 1:
The patent segments the optical waveguide into two functional sides, adding the light-leakage prevention element on the second side face. This segmentation creates a dedicated privacy protection function without significantly complicating the overall device structure, as the added element is integrated into the existing waveguide architecture
Solution Approach 2:
The light-leakage prevention element acts as an intermediary between the optical waveguide and the external environment. It mediates the interaction by selectively blocking light leakage while allowing the optical waveguide to maintain its simple structure and functionality, thus protecting privacy without significantly increasing device complexity
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 solution effectively reduces light leakage and enhances light efficiency, improving the brightness and reducing power consumption of AR devices, while also protecting user privacy.
Implementation Method 1
the light-leakage prevention element is configured to reflect light incident from the optical waveguide to the light-leakage prevention element
Implementation Method 2
the light-leakage prevention element is configured to absorb light incident from the optical waveguide to the light-leakage prevention element
Implementation Method 3
optical waveguide systems based on diffraction gratings
Data Source
AI summary
An optical waveguide system and an augmented reality device are disclosed and have advantages of reducing the light leakage rate and improving the light energy efficiency. The optical waveguide system comprises an optical waveguide, the optical waveguide comprises a first side face and a second side face opposite each other; the first side face is provided with a grating; the second side face is provided with a light-leakage prevention element configured to reduce light emitted from the second side face. The light-leakage prevention element may reflect, diffract or absorb light incident to the light-leakage prevention element. Therefore, light emitted from the second side face of the optical waveguide (1) can be reduced, that is, a light leakage phenomenon is reduced; and the light can also be reflected to the grating by reflection or diffraction, thereby improving the utilization rate of light energy, that is, improving the light efficiency.