Optical Prism Interlock for Folded Lens Z-Height Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional small cameras in mobile devices face challenges in capturing high-resolution, high-quality images due to limitations in compact imaging lens systems, requiring smaller pixel sizes and larger image sensors while maintaining a compact form factor.
Innovation Solution
A folded lens system utilizing an optical prism with an interlock structure that redirects the optical axis, reducing the Z-height and integrating refractive power to minimize the number of lens elements and enhance image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a compact imaging lens system is used in small form factor cameras, then the camera size is reduced, but image quality and resolution deteriorate
Solution Approach 1:
The patent introduces a folded optical path using a beam splitter and mirror to transition from a linear optical axis to a folded configuration. This dimensional change allows the lens system to achieve a compact form factor while maintaining sufficient image quality by redirecting light through multiple dimensions rather than requiring a long linear path.
Solution Approach 2:
The imaging system is divided into separate functional modules: a telephoto lens element, a beam splitter, and a mirror. This segmentation allows each component to be optimized independently for its specific function while working together to achieve both compactness and acceptable image quality.
2Volume of moving object
If the pixel size is reduced to maintain small form factor, then the camera size is reduced, but resolution deteriorates
Solution Approach 1:
By folding the optical path into a compact three-dimensional configuration rather than extending it linearly, the system accommodates larger pixel sizes within a smaller overall camera volume, thereby maintaining resolution while reducing camera size.
3Length of stationary object
If the Z-height is reduced for compactness, then the camera size is reduced, but optical alignment becomes more difficult
Solution Approach 1:
The beam splitter serves as an intermediary component that facilitates the folded optical path while providing a reference surface for alignment. The mirror similarly acts as an intermediary that redirects light while offering alignment features, making the compact Z-height configuration achievable with acceptable alignment precision.
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 enables high-resolution image capture with reduced Z-height, improving image quality and ease of assembly by precisely aligning optical axes, thus addressing the compactness and image quality constraints of small form factor cameras.
Implementation Method 1
the prism redirects light from a first optical axis to a second optical axis
Implementation Method 2
the reflective surface reflects light in the prism to fold the optical axis due to total internal reflection (TIR)
Implementation Method 3
A reflective surface of the prism provides a folded optical axis for the lens system by bending the optical axis
Data Source
AI summary
An optical prism that includes an interlock structure that precisely couples to a complementary structure of a refractive lens. For precision, the interlock structure may be formed at the same time and using the same technique as the optical surface of the prism. The interlock structure provides high accuracy when assembling a folded lens system by precisely aligning the object side optical surface of the lens with the image side optical surface of the prism so that the optical axis is centered in the lens. The prism may have refractive power. A portion of the object side surface may be coated with an opaque material to provide an aperture stop at that surface.