Folded Three-Lens Optical Layout for Wide FOV Diopter Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems for smart head wear devices, such as those used in virtual reality, augmented reality, and mixed reality, face challenges in achieving a small volume, light weight, and excellent imaging performance, particularly in terms of field of view, optical distortion, and diopter adjustment.
Innovation Solution
An optical system design featuring a three-lens configuration with a partial reflective element and a composite film comprising a polarization reflective film and a quarter wave plate, allowing for a folding structure and adjustable diopter through a movable third lens, along with aspheric surfaces to reduce volume and enhance imaging quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a traditional optical system design is used, then the imaging performance can be maintained, but the volume and weight of the optical system will be large
Solution Approach 1:
The patent employs a folded optical path design where the optical system bends the light path at angles rather than using a straight linear arrangement. This dimensional reconfiguration allows the optical components to be arranged in a compact folded structure, reducing the overall volume of the optical system from what would be required in a traditional straight-path design, while maintaining the necessary optical path length for imaging performance
Solution Approach 2:
The patent integrates multiple optical functions into a nested three-lens configuration where lenses are arranged in a compact sequence with the third lens positioned to provide diopter adjustment. This nested arrangement allows the optical components to be tightly packed, reducing the overall volume while maintaining the functional requirements for imaging and focus adjustment
2Adaptability or versatility
If the field of view is increased, then the user experience is improved, but the optical distortion increases
Solution Approach 1:
The patent employs aspheric surfaces on the lenses, particularly on the third lens which provides diopter adjustment. These curved non-spherical surfaces are specifically designed to correct optical aberrations and reduce distortion that would otherwise increase with a wider field of view, allowing the system to maintain high imaging quality across an expanded angular range
Solution Approach 2:
The patent applies different surface characteristics to different regions of the optical system. The aspheric surfaces are strategically positioned on specific lenses where they are most effective at correcting distortion, while other surfaces maintain simpler geometries. This localized optimization allows the system to achieve wide field of view with controlled distortion
3Adaptability or versatility
If the diopter adjustment range is extended to fit different myopia levels, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The patent implements a movable third lens that can be dynamically adjusted along the optical axis to provide diopter changes from 0D to 8D. This dynamic positioning mechanism allows a single lens to perform multiple diopter adjustment functions that would otherwise require multiple fixed lenses or complex variable focus mechanisms, thereby extending the adaptability range while controlling structural complexity
Solution Approach 2:
The third lens serves multiple functions simultaneously: it provides the primary diopter adjustment for myopia correction, contributes to the overall focusing capability of the system, and helps control optical aberrations. This multi-functionality allows the system to achieve a wide diopter adjustment range without proportionally increasing the number of components or overall structural complexity
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 design achieves a compact form factor with a maximum visible diameter of 10 mm or more, a field of view between 95° and 115°, and diopter adjustment from 0D to 8D, providing high imaging performance and reduced optical distortion, suitable for various myopia levels without tedious adjustments.
Implementation Method 1
a quarter wave plate, the left circularly polarized light passes through the quarter wave plate for the first time to be converted into a linearly polarized S light
Implementation Method 2
a polarization reflective film, the reflected light at this time is still a linearly polarized S light, and then passes through the quarter wave plate
Implementation Method 3
a partial reflective element is provided on a front surface of the third lens; the reflected light is converted into a right circularly polarized (RCP) light
Data Source
AI summary
An optical system is provided, including from a front side to a back side: an image plane provided with a circular polarizer attached to a back side of thereof for transmitting light; a third lens configured to move forward and backward along an optical axis to change a diopter of the optical system, a partial reflective element is provided on a front surface of the third lens; a second lens; a first lens including a composite film is provide at a front surface thereof, the composite film includes a polarization reflective film attached to the front surface of the first lens and a quarter wave plate attached to a front side of the polarization reflective film; and an aperture located at the back side of the optical system; a maximum visible diameter VD satisfies VD≥10.00 mm, a maximum effective radius of each lens SDmax satisfies SDmax≤22.25 mm.