Optical Apparatus Support Ring Thermal Expansion Compensation
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Solution Overview
Problem
The existing optical apparatus for vehicle cameras faces issues with increased size due to the need for different thermal expansion-contraction ratios and fails to maintain focus when ambient temperature rises, as the inner cylindrical portion is fixed away from the lens, leading to focal point movement.
Innovation Solution
An optical apparatus with a support system that uses a lens module with a single expansion-contraction ratio, where the support is designed to maintain alignment between the imager and lenses by expanding or contracting to cancel focal point movement caused by temperature changes, allowing the lens module to remain focused on the imager without increasing the apparatus size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the inner cylindrical portion is fixed to the outer cylindrical portion at a position away from the lens, then the lens is supported at a predetermined distance from the imager, but the size of the optical apparatus increases
Solution Approach 1:
The patent moves the connection position from a distant location on the outer cylindrical portion to a position near the lens, utilizing the spatial dimension closer to the optical element. This dimensional repositioning reduces the overall apparatus size while maintaining lens support functionality through the support ring structure
Solution Approach 2:
The support ring is nested within the outer cylindrical portion and directly connects to the lens, creating a compact nested structure. This nesting eliminates the need for a long outer cylindrical portion extending away from the lens, thereby reducing apparatus size while maintaining structural support
2Reliability
If two materials having different thermal expansion-contraction ratios are used, then temperature compensation is achieved, but the device complexity increases
Solution Approach 1:
The patent changes the thermal expansion parameter by using a support ring made of a material with a larger thermal expansion coefficient than the outer cylindrical portion. This parameter difference enables automatic temperature compensation where the support ring expands more at high temperatures to maintain lens-imager distance, achieving reliability without complex multi-material construction
Solution Approach 2:
The invention directly applies thermal expansion principles by selecting materials with different expansion characteristics. The support ring's higher thermal expansion ratio is intentionally utilized to counteract the effects of temperature changes on the optical system, providing passive temperature compensation through material physics rather than active control mechanisms
3Manufacturing precision
If a lens module with multiple lenses is used, then image quality is improved, but the focal point moves along the optical axis when ambient temperature rises
Solution Approach 1:
The patent applies preliminary anti-action by pre-configuring the support ring with a larger thermal expansion ratio to counteract the focal point movement that occurs when temperature rises. This preemptive design ensures that as the lens module expands with heat causing focal point shift, the support ring simultaneously expands to maintain the correct lens-imager distance, preventing focus degradation before it occurs
Solution Approach 2:
The invention uses thermal expansion of the support ring material to compensate for temperature-induced focal point movement in the lens module. The differential thermal expansion between the support ring and the lens module creates a self-correcting mechanism that maintains focus stability across temperature variations
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
This configuration minimizes the size increase of the optical apparatus, ensures focus is maintained across temperature changes, and allows the use of a lens module with a single material, ensuring effective temperature compensation.
Implementation Method 1
The support is formed such that an expansion-contraction ratio, at which the support expands or contracts along the optical axis in accord with changes in ambient temperature of the optical apparatus, becomes a first expansion-contraction ratio at which the support expands or contracts so as to cancel a movement of the focal point occurring in the lens module along the optical axis in accord with the changes in ambient temperature of the optical apparatus.
Data Source
AI summary
An optical apparatus captures imaging light entering into an imager to acquire an image of an object. The optical apparatus includes a lens module and a support. The lens module is configured by a combination of two or more lenses, captures the imaging light through the lenses, and focuses the captured imaging light on the imager. The support supports the lens module at a position apart from the imager by a predetermined distance, such that the imager and the lenses are aligned on the optical axis, and a focal point of the imaging light is formed on the imager. The support is formed such that an expansion-contraction ratio, at which the support expands or contracts along the optical axis in accord with changes in ambient temperature of the optical apparatus, becomes a first expansion-contraction ratio at which the support expands or contracts so as to cancel a movement of the focal point occurring in the lens module along the optical axis in accord with the changes in ambient temperature of the optical apparatus.