Linear Actuator Assembly for Compact Imaging Positioning
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Solution Overview
Problem
Modern imaging apparatuses face challenges with positional inaccuracies due to bulky motors and gaps in motor assemblies, which affect image quality and precision in devices like cameras and smartphones.
Innovation Solution
The use of linear actuator assemblies with direct and continuous contact between a movable carriage and paired linear actuators or a static guide rod, utilizing piezoelectric components and elastomeric bushings to ensure precise and accurate positioning, eliminating gaps and enhancing repeatability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard motors (stepper, DC, or piezoelectric) are used to move the lens, then the motor can provide the necessary driving force, but the motor assembly becomes bulky and may not achieve the required positional repeatability
Solution Approach 1:
The motor assembly is segmented into separate functional components: the piezoelectric motor unit, the lens carriage, and the coupling mechanism. This segmentation allows each component to be optimized independently, reducing overall assembly size while maintaining performance
Solution Approach 2:
The lens carriage is nested within the motor assembly structure, with the coupling mechanism integrated between the motor and carriage. This nesting approach minimizes the overall volume by eliminating separate mounting structures and reducing clearance requirements
2Manufacturing precision
If standard fabrication tolerances are used in the coupling system, then manufacturing is easier, but gaps arise in the coupling that lead to positional inaccuracies
Solution Approach 1:
The coupling mechanism incorporates compliant elements that dynamically adapt to manufacturing variations, allowing the system to compensate for small dimensional deviations while maintaining tight effective tolerances
Solution Approach 2:
A precision coupling mechanism acts as an intermediary between the motor and lens carriage, providing a reference surface that eliminates the accumulation of tolerances and prevents gap formation
3Force
If bulky motors are used to ensure sufficient driving force, then the motor can move the lens effectively, but the overall device size increases and precision is compromised
Solution Approach 1:
The traditional mechanical coupling between motor and lens is replaced with a direct-drive or near-direct-drive configuration, eliminating intermediate mechanical elements that could introduce play or inaccuracies while maintaining sufficient driving force
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 highly accurate and compact positioning of movable components, improving image quality by maintaining continuous contact and reducing positional inaccuracies, thus meeting the precision standards of modern imaging devices.
Implementation Method 1
the base including a piezoelectric component to selectively oscillate the rod
Implementation Method 2
A first pair of elastomeric bushings may be coupled to the chassis to support the first linear actuator at opposing ends thereof
Data Source
AI summary
A linear actuator assembly is provided, the assembly including a linear actuator, an elongated guide spaced in parallel alignment with the linear actuator and a movable carriage disposed therebetween. The carriage includes a first notch to receive a rod of the linear actuator and a second notch to receive the guide. The carriage remains in direct and continuous contact with the linear actuator and the guide at the first notch and second notch, respectively, when the carriage moves linearly back and forth along a travel axis.