Asymmetric Aperture Light-Shielding for Off-Axis Optical Systems
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Solution Overview
Problem
Existing display systems with non-axially symmetrical optical systems face challenges in effectively blocking unnecessary light due to the axial symmetry of aperture restriction means in previous technologies, leading to incomplete light blocking and reduced image quality.
Innovation Solution
A display module with a light-guiding optical device that includes first and second optical surfaces with corresponding light-shielding portions, where the first aperture on the incidence surface has an asymmetrical shape different from the second aperture on the emission surface, allowing for effective light blocking without relying on diaphragm members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an axially symmetrical aperture restriction means is used in a non-axially symmetrical optical system, then the device complexity is reduced, but the light blocking effectiveness deteriorates
Solution Approach 1:
The patent applies asymmetry by configuring the aperture restriction means to have an asymmetric aperture shape that matches the non-axially symmetrical optical system. The aperture shape is specifically designed to correspond to the shape of the luminous flux, allowing effective blocking of unnecessary light while maintaining the non-axially symmetrical characteristics of the optical system.
2Manufacturing precision
If an axially symmetrical aperture shape is used, then the manufacturing precision is simplified, but the light blocking completeness deteriorates
Solution Approach 1:
The patent applies local quality by making the aperture shape locally adapted to the specific requirements of the non-axially symmetrical optical system. The aperture shape is designed to match the local distribution of luminous flux at different positions, ensuring that unnecessary light is blocked effectively while maintaining manufacturing feasibility.
Data Source
AI summary
Provided is a display module including a display element, and a light-guiding optical device that guides image light emitted from the display element to form an exit pupil, in which the light-guiding optical device is an off-axis optical system. The off-axis optical system includes a first optical surface, a second optical surface, a first light-shielding portion, the first light-shielding portion being formed at the first optical surface, and a second light-shielding portion, the second light-shielding portion being formed at the second optical surface, in which the first light-shielding portion exposes, through a first aperture, a part of the first optical surface, and the second light-shielding portion exposes, through a second aperture, a part of the second optical surface, the first aperture and the second aperture having mutually different shapes.