Folded HMD Optics With Adjacent Diffraction Surfaces for Color Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems for head-mounted displays (HMDs) face challenges in achieving high image definition and correcting chromatic aberrations while maintaining a compact design, particularly in folded optical systems.
Innovation Solution
The optical system incorporates a first and second lens with adjacent diffraction surfaces and transmissive reflective surfaces to guide light from a display surface to an observation side, using a combination of refractive and diffractive elements to reduce flare and correct aberrations, with materials selected for high diffraction efficiency and chromatic aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a folded optical system is used to achieve a compact form factor, then the device size is reduced, but image definition and chromatic aberration correction become more difficult
Solution Approach 1:
The patent combines refractive surfaces and diffractive surfaces on the same lens surfaces. Specifically, the first lens has a first diffractive surface on its object-side surface, and the second lens has a second diffractive surface on its image-side surface. This merging of refractive and diffractive functionalities on compact lens elements enables effective chromatic aberration correction and high image definition within a folded optical system's limited space.
Solution Approach 2:
The patent employs composite optical structures by integrating diffractive optical elements with refractive lens materials. The diffractive surfaces are formed on the lens surfaces through composite manufacturing processes, creating hybrid optical components that leverage both refractive and diffractive properties to correct chromatic aberrations while maintaining a compact form factor.
2Manufacturing precision
If diffractive surfaces are added to correct chromatic aberration, then chromatic aberration correction is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple optical functions into fewer components by integrating diffractive surfaces directly onto the lens elements. The first lens combines refraction and diffraction on its object-side surface, and the second lens combines refraction and diffraction on its image-side surface. This consolidation reduces the total number of separate optical elements needed, thereby managing device complexity while achieving superior chromatic aberration correction.
Solution Approach 2:
The diffractive surfaces on the lens elements serve multiple functions: they provide chromatic aberration correction, contribute to overall optical power, and work in conjunction with the refractive surfaces to control light propagation. This multi-functionality reduces the need for additional dedicated correction elements, managing system complexity while achieving high chromatic aberration correction.
3Manufacturing precision
If multiple lenses with diffraction surfaces are used to improve image quality, then image definition is improved, but the number of components and device complexity increase
Solution Approach 1:
The patent merges diffractive and refractive functions into the existing lens elements of the folded optical system. By adding diffractive surfaces to the first and second lenses rather than introducing separate diffractive optical elements, the system achieves enhanced image definition while minimizing the increase in component count. The diffractive surfaces are integrated into the lens manufacturing process, effectively combining multiple functions in fewer physical 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 achieves high diffraction efficiency and effective chromatic aberration correction across a wide visible wavelength range, enhancing image quality in a compact form factor.
Implementation Method 1
A surface of the first lens disposed on the display surface side of the first lens includes a first diffraction surface. A surface of the second lens disposed on the observation side of the second lens includes a second diffraction surface.
Implementation Method 2
an first lens L1, a second lens L2 disposed on a display surface side relative to the first lens L1
Implementation Method 3
a first transmissive reflective surface HM1 and a second transmissive reflective surface HM2 disposed at positions different from the surface of the first lens disposed on the display surface side of the first lens L1 and the surface of the second lens disposed on the observation side of the second lens L2
Data Source
AI summary
An optical system includes a first lens, a second lens disposed on a display surface side relative to the first lens, and a third lens with positive refractive power disposed on the observation side relative to the first lens or on the display surface side relative to the second lens. A surface of the first lens on the display surface side includes a first diffraction surface. A surface of the second lens on the observation side includes a second diffraction surface. The first diffraction surface and the second diffraction surface are adjacent to each other. The optical system further includes a first transmissive reflective surface and a second transmissive reflective surface disposed at positions different from the surface of the first lens disposed on the display surface side of the first lens and the surface of the second lens disposed on the observation side of the second lens.