Optical Device Stray Light Reduction via Segmented Light Guiding
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Solution Overview
Problem
Head-mounted displays (HMDs) using optical devices with light guiding members suffer from stray light issues, resulting in low image quality due to the inclusion of stray light between the first and second light guiding members.
Innovation Solution
An optical device design featuring a first light guiding member with semitransparent layers and a second light guiding member, where light is totally reflected and deflected to minimize stray light inclusion, with specific angles and configurations to enhance image quality, including the use of semitransparent mirror films and sectional area enlarging portions to prevent nonuniformity and stray light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If two deflecting means are arranged on a light guide plate to widen the angle of view, then the field of view is improved, but stray light is included in the emitted light resulting in low image quality
Solution Approach 1:
The light guide plate is divided into multiple light guiding members (first light guiding member and second light guiding member), each with its own deflecting means. This segmentation allows independent control of light paths and enables the removal of stray light through the first light guiding member while maintaining the widened field of view function through the second light guiding member.
Solution Approach 2:
Stray light is extracted and removed from the optical path by positioning the first light guiding member to receive and eliminate stray light before it reaches the second light guiding member. The first light guiding member acts as a filtering element that takes out harmful stray light while allowing useful image light to pass through.
2Object-affected harmful factors
If light is guided through multiple light guiding members to improve image quality, then stray light is reduced, but the device complexity increases
Solution Approach 1:
Multiple light guiding members are merged into a single integrated optical device structure. The first and second light guiding members are positioned adjacent to each other with their respective deflecting means, combining the stray light removal function and the widened field of view function into one unified device rather than separate components.
Solution Approach 2:
The optical device performs multiple functions simultaneously: the first light guiding member removes stray light, the second light guiding member provides widened field of view, and together they deliver high image quality. This multi-functionality reduces the need for additional separate components.
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 effectively reduces stray light, enhancing image quality and providing a wider field of view while maintaining high image clarity and brightness, suitable for head-mounted displays.
Implementation Method 1
light entering from the fifth surface being totally reflected within the first light guiding member
Implementation Method 2
being deflected by the first deflecting means
Implementation Method 3
entering the eighth surface disposed so as to be separated from the third surface, being totally reflected between the seventh surface and the ninth surface
Implementation Method 4
being deflected by the second deflecting means
Data Source
AI summary
There is provided an optical device that provides a high quality image. The optical device includes a first light guiding member that has first through sixth surfaces and a first deflecting means. The first, second, and fifth surfaces are opposed to the third, fourth, and sixth surfaces, respectively. The optical device further includes a second light guiding member that has seventh through twelfth surfaces and a second deflecting means. The seventh, eighth, and eleventh surfaces are opposed to the ninth, tenth, and twelfth surfaces, respectively. Light that enters from the fifth surface is totally reflected within the first light guiding member, is deflected by the first deflecting means, is emitted from the third surface, enters the eighth surface, is totally reflected between the seventh surface and the ninth surface, is deflected by the second deflecting means, and is emitted from the seventh surface.