Asymmetric Reflective Unit for AR Optical Devices
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Solution Overview
Problem
Conventional augmented reality optical devices face issues with luminous uniformity and field of view due to their complex configurations and the use of point-symmetric reflective units, which result in uneven brightness distribution and limited focal adjustment without additional hardware or user operations.
Innovation Solution
The use of asymmetric reflective units smaller than the human pupil, disposed on or within the optical device, which improve luminous uniformity and depth of field by reflecting augmented reality images towards the user's pupil, allowing for a wider field of view and eliminating the need for separate focal length adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a point-symmetric reflective unit is used, then the depth of field is deepened and a pinhole effect is provided, but luminous uniformity becomes uneven with large brightness difference between central and peripheral portions
Solution Approach 1:
The patent applies asymmetry by changing the reflective unit shape from point-symmetric (circular) to asymmetric shapes such as rectangular, triangular, or trapezoidal. This shape transformation redistributes the light reflection pattern, reducing the brightness difference between central and peripheral portions while preserving the depth of field enhancement effect. The asymmetric geometry modifies how light rays are directed through the pupil, achieving more uniform luminous distribution across the visual field.
2Reliability
If conventional optical systems with prisms are used, then virtual images can be reflected, but the device configuration becomes complicated and weight and volume increase
Solution Approach 1:
The patent extracts the essential function of light reflection from complex prism assemblies and implements it through a simplified reflective unit integrated directly into the lens structure. By removing unnecessary optical components and retaining only the critical reflection function, the system achieves virtual image reflection with significantly reduced configuration complexity, weight, and volume.
Solution Approach 2:
The reflective unit is merged with the lens structure, combining the refraction function of the lens with the reflection function of the asymmetric unit. This integration eliminates the need for separate prism components and their associated mounting structures, thereby simplifying the overall optical system while maintaining the ability to reflect virtual images effectively.
3Reliability
If conventional optical systems are used, then virtual images can be displayed, but manufacturing processes become complicated and manufacturing costs increase
Solution Approach 1:
The patent extracts the core display function from complex multi-component optical systems and implements it through a simplified structure with an asymmetric reflective unit. This extraction reduces the number of manufacturing steps, eliminates complex alignment procedures, and simplifies quality control, thereby reducing manufacturing costs while preserving virtual image display capability.
4Reliability
If focal length adjustment mechanisms are added, then virtual images remain in focus during focal length changes, but separate operations or additional hardware and software are required
Solution Approach 1:
The asymmetric reflective unit configuration inherently provides focus adaptation without requiring external control mechanisms. The geometric properties of the asymmetric shape automatically adjust the optical path to maintain focus during focal length changes, eliminating the need for separate user operations, processors, or control software. The system serves itself by using the reflective unit's geometry to adapt to focal 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
The solution enhances luminous uniformity and field of view while maintaining a deep depth of field, ensuring a clear and evenly lit augmented reality experience without requiring additional hardware or user operations for focal adjustments.
Implementation Method 1
a reflective unit disposed on the surface of the optical means or inside the optical means, and configured to reflect image light corresponding to an image for augmented reality
Implementation Method 2
an optical means for transmitting at least part of visible light therethrough
Data Source
AI summary
The present invention provides an optical device for augmented reality, the optical device including: an optical means for transmitting at least part of visible light therethrough; and a reflective unit disposed on the surface of or in the inside of the optical means, and configured to reflect image light corresponding to an image for augmented reality, output from an image output unit, toward the pupil of an eye of a user; wherein the reflective unit is formed in an asymmetric shape representing a shape other than a point-symmetric shape; and wherein the point-symmetric shape is a shape in which there is a specific point that allows the shape to be always the same for all rotation angles when the reflective unit is rotated around a specific point on the plane of the reflective unit, and the asymmetric shape is a shape that is not the point-symmetric shape.