Ocular Optical System With Asymmetric Phase Plate Alignment
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Solution Overview
Problem
Existing polarizing optical systems face challenges in reducing size and weight while maintaining optical performance due to phase shifts between phase plates, particularly when one phase plate is bonded to a lens with a rotationally symmetric shape, leading to degradation in optical performance.
Innovation Solution
The use of non-rotationally symmetric shaped phase plates and polarization separation elements, integrated with lenses through adhesive layers, allows for precise alignment and reduction of phase shifts, ensuring orthogonal polarization directions and stable bonding, thereby enhancing optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If two phase plates are installed in a polarizing optical system to reduce size and weight, then the optical system becomes more compact, but phase shift between the phase plates degrades optical performance
Solution Approach 1:
The patent introduces asymmetric shape determination portions (protrusions or recesses) on specific phase plates that break the rotational symmetry. This asymmetric design enables precise angular alignment between phase plates during assembly, ensuring that the phase shift relationship is correctly maintained. The asymmetric features act as mechanical guides that constrain the relative rotation of phase plates, thereby resolving the phase shift issue while keeping the compact dual-phase-plate configuration.
2Device complexity
If a phase plate is bonded to a lens with rotationally symmetric shape, then the optical system is simplified, but it becomes difficult to determine the phase of the phase plate
Solution Approach 1:
The patent adds asymmetric shape determination portions to phase plates that are bonded to rotationally symmetric lenses. These asymmetric features (protrusions or recesses) provide unique angular reference markers that break the rotational symmetry ambiguity. During assembly, the asymmetric features guide the correct rotational positioning of the phase plate relative to the lens, enabling precise phase determination even when the lens itself has rotational symmetry.
3Manufacturing precision
If asymmetric shape determination portions are provided on phase plates, then phase alignment is improved, but the manufacturing complexity of the phase plates increases
Solution Approach 1:
The asymmetric shape determination portions are localized features added only to specific regions of the phase plates, rather than redesigning the entire phase plate structure. The protrusions or recesses are small, discrete geometric features that can be incorporated into the phase plate manufacturing process with minimal additional complexity. This localized approach maintains the overall simplicity of phase plate fabrication while providing the necessary alignment functionality.
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 configuration results in a compact optical system with improved optical performance by minimizing ghost light and color shifts, enabling wide-angle image observation with reduced size and weight.
Implementation Method 1
a polarization separation element configured to reflect first linearly polarized light and allow second linearly polarized light to pass therethrough in a polarization direction orthogonal to a polarization direction of the first linearly polarized light
Implementation Method 2
The first phase plate has a shape that determines a phase. The second phase plate has a rotationally symmetric shaped portion and a non-rotationally symmetric shaped portion
Data Source
AI summary
An ocular optical system that guides light from a display element to an eye of an observer includes a first phase plate, a second phase plate, one or more lenses, and a polarization separation element configured to reflect first linearly polarized light and allow second linearly polarized light to pass therethrough in a polarization direction orthogonal to a polarization direction of the first linearly polarized light. The second phase plate is in contact with and held by a predetermined lens among the one or more lenses. The first phase plate has a shape that determines a phase. An outer shape of the predetermined lens is a rotationally symmetric shape. The second phase plate has a rotationally symmetric shaped portion and a non-rotationally symmetric shaped portion.