Crossed-Ball Variable Focus Lens Assembly for Fast Stable Autofocus
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Solution Overview
Problem
Conventional variable focus lens implementations are unsuitable for small form factor devices due to size constraints, sensitivity to vibrations, and slow response rates, making them unreliable for mobile imaging applications where quick and precise focusing is required without high energy consumption.
Innovation Solution
A variable focus lens assembly using a lens barrel assembly positioned by interactions between positioning magnets and coils, with bearing balls for mobility, allowing rapid repositioning and reduced friction, enabling compact, reliable, and low-power focusing within small form factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional variable focus lens implementations are used, then focusing capability is achieved, but the device size becomes too large for small form factor devices
Solution Approach 1:
The lens assembly is divided into separate functional components: a lens module, a positioning mechanism with coils and magnets, and bearing balls. This segmentation allows each component to be optimized independently, reducing overall size while maintaining focusing reliability through specialized design of each segment.
Solution Approach 2:
The positioning coils are arranged in a nested configuration around the lens module, with multiple coils positioned at different locations (first coil at first location, second coil at second location). This nested arrangement maximizes the use of available space within the small form factor housing, allowing the focusing mechanism to be compact while maintaining effective control over the lens position.
2Speed
If conventional variable focus lens implementations are used, then focusing capability is achieved, but response rate becomes slow
Solution Approach 1:
The patent replaces conventional mechanical focusing mechanisms (such as screw drives or rack-and-pinion systems) with an electromagnetic positioning system using coils and permanent magnets. This substitution eliminates mechanical friction and inertia, enabling faster response rates and more precise positioning while reducing energy consumption through efficient electromagnetic actuation.
Solution Approach 2:
The positioning system uses dynamic control through independently controllable coils that can rapidly adjust the lens position. The first coil and second coil can be energized in different sequences and with different current levels to achieve fast, precise focusing adjustments, allowing the system to adapt quickly to changing focus requirements without excessive energy consumption.
3Reliability
If conventional variable focus lens implementations are used, then focusing capability is achieved, but sensitivity to vibrations increases
Solution Approach 1:
The patent introduces bearing balls as intermediary elements between the lens module and the housing. These bearing balls provide a low-friction support mechanism that isolates the lens module from vibrations transmitted through the housing, reducing vibration sensitivity while maintaining stable lens positioning for reliable focusing.
Solution Approach 2:
The electromagnetic positioning system replaces mechanical connection elements that would transmit vibrations directly to the lens module. By using magnetic fields for positioning rather than rigid mechanical linkages, the system naturally isolates the optical components from vibration, improving reliability in mobile imaging applications.
4Ease of operation
If bearing balls are used for mobility, then friction is reduced, but device complexity increases
Solution Approach 1:
The bearing balls are integrated into the existing housing and lens module structure, combining the support function with the overall assembly design. The first bearing ball and second bearing ball are positioned at strategic locations where they naturally support the lens module without requiring additional complex mounting mechanisms, reducing overall device complexity while providing smooth mobility.
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 provides a compact, reliable, and high-speed focusing mechanism that is less susceptible to vibrations, optimizing power consumption and improving the effective range for image capture in small form factor imaging apparatuses.
Implementation Method 1
a wired coil board configured to produce a magnetic flux upon energization. Additionally or alternatively, the optical member further comprises at least one permanent magnet on at least a portion of the optical member such that at all movement positions of the optical member, the at least one permanent magnet is in interactable proximity of the magnetic flux produced by the wired coil board
Implementation Method 2
Each ball bearing of the first pair of bearing balls is housed in a respective one of the two front tubular slots and is configured to movably support the optical member within the housing at a first side of the optical member. Each ball bearing of the second pair of bearing balls is housed in a respective one of the two rear tubular slots and is configured to movably support the optical member within the housing at a second side of the optical member
Data Source
AI summary
Various embodiments described herein provide a variable focus lens assembly. Some embodiments are designed to enable repositioning of one or more components, such as a lens barrel assembly, to adjust the focus of the variable focus lens assembly. Some example variable focus lens assemblies include a module base housing a lens barrel assembly having a pair of positioning magnets, a pair of positioning coil assemblies associated with the positioning magnets, and at least one pair of bearing balls movably supporting the lens barrel assembly. The positioning coil assemblies together with the positioning magnets are configured to exert various magnetic fields to reposition the lens barrel assembly. Further embodiments are provided for imaging apparatus including at least one variable focus lens assembly described herein.