Adjustable-Focus Lens Assembly for Mixed Reality
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Solution Overview
Problem
Conventional camera lens assemblies face challenges in maintaining performance metrics like resolution, dynamic range, and image acquisition time as cameras become smaller, and they are vulnerable to external contaminants. Additionally, the process of adjusting the entire lens stack for focus requires significant power and can cause the 'camera breathing' effect, which is undesirable in applications like Mixed Reality.
Innovation Solution
An adjustable-focus lens assembly is introduced, where a fixed lens assembly is not moved during focusing operations, and an adjustable lens assembly is positioned between the image sensor and the fixed lens assembly. This setup allows for quicker focusing with less power consumption and reduces the 'camera breathing' effect by adjusting only the adjustable lens assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the entire lens stack is moved for focusing, then the camera can achieve focus adjustment, but it consumes significant power and causes the camera breathing effect
Solution Approach 1:
The lens assembly is divided into two independent parts: a fixed lens assembly and a movable adjustable lens assembly. The adjustable lens assembly is separated from the fixed lens assembly and can move independently along the optical axis to perform focusing, while the fixed lens assembly remains stationary to maintain optical stability and prevent camera breathing effect.
Solution Approach 2:
The focusing function is extracted from the entire lens stack and assigned specifically to the adjustable lens assembly. This allows the fixed lens assembly to remain stationary while the adjustable lens assembly handles all focusing movements, reducing power consumption and eliminating camera breathing.
2Ease of operation
If the entire lens stack is moved for focusing, then the camera can achieve focus adjustment, but the focusing process is slow and takes significant time
Solution Approach 1:
The lens assembly is segmented into fixed and movable portions, allowing only the lightweight adjustable lens assembly to move for focusing. This reduces the mass that needs to be accelerated and decelerated during focusing operations, significantly reducing focusing time and improving response speed.
3Reliability
If the fixed lens assembly is sealed to prevent contaminant ingress, then the camera becomes resistant to external contaminants, but the lens stack cannot be adjusted for focus
Solution Approach 1:
The lens system is divided into a sealed fixed lens assembly that maintains contaminant resistance, and a separate adjustable lens assembly that performs focusing. The fixed lens assembly can be hermetically sealed while the adjustable lens assembly moves independently in a separate chamber or through a sealed interface, maintaining both protection and adjustability.
Solution Approach 2:
A sealed interface or barrier is introduced between the fixed lens assembly and the adjustable lens assembly. This intermediary structure allows the adjustable lens assembly to move for focusing while preventing contaminant ingress to the fixed lens assembly, maintaining both adjustability and environmental protection.
4Volume of moving object
If the camera module is made smaller to fit more devices, then the camera can be deployed in more contexts, but performance metrics like resolution and dynamic range become harder to meet
Solution Approach 1:
The lens assembly is segmented into fixed and adjustable components, allowing the overall camera module to be compact while maintaining optical performance. The fixed lens assembly can be optimized for size and the adjustable lens assembly adds minimal bulk while providing focusing capability, enabling small form factor with high performance.
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 waterproof seal for the camera module, reduces power consumption during focusing, and minimizes the 'camera breathing' effect, enhancing the camera's performance and usability in various contexts, including Mixed Reality applications.
Implementation Method 1
an adjustable lens assembly is disposed between an image sensor and a fixed lens assembly. The adjustable lens assembly is configured to selectively modify a focal length of the camera module by adjusting the adjustable lens assembly along an optical axis of the adjustable lens to focus image light to the image sensor
Data Source
AI summary
A digital camera module includes a housing, an image sensor, a fixed lens assembly, and an adjustable lens assembly. The fixed lens assembly is at least partially coupled to the housing. The adjustable lens assembly is positioned within the housing between the image sensor and the fixed lens assembly. The adjustable lens assembly is configured to selectively modify a focal length of the digital camera module.