Shiftable Lens Unit With Resin Layer for Chromatic Aberration Control
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Solution Overview
Problem
Existing optical systems face challenges in suppressing chromatic aberration while maintaining a movable unit that is decentered from the optical axis, as they either result in a large and heavy driving mechanism or struggle with chromatic aberration correction due to the lightweight nature of the image stabilizing unit.
Innovation Solution
Incorporating a resin layer within the image stabilizing unit that is cemented with a base lens, adhering to specific focal length and refractive power conditions, to maintain the unit's small and lightweight nature while effectively correcting chromatic aberration and eccentric coma during shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire third lens unit is used as an image stabilizing unit, then image stabilization is achieved, but the driving mechanism becomes larger and the lens barrel becomes larger
Solution Approach 1:
The third lens unit is divided into multiple lenses (positive, negative, positive, negative), but only a specific subset is used as the image stabilizing unit. This segmentation allows the stabilizing function to be achieved with a smaller, lighter subset of lenses rather than moving the entire heavy third lens unit, thus reducing the size of the driving mechanism and lens barrel while maintaining image stabilization capability.
Solution Approach 2:
A specific lens or lens group is extracted from the third lens unit to serve as the image stabilizing unit. This extracted subset performs the image stabilization function independently, allowing the remaining lenses to stay fixed. This extraction reduces the mass that needs to be moved for stabilization, thereby reducing the driving mechanism size and lens barrel volume.
2Volume of moving object
If a lightweight image stabilizing unit with fewer lenses is used, then the lens barrel size is reduced, but chromatic aberration becomes difficult to suppress
Solution Approach 1:
The image stabilizing unit employs a composite lens structure combining multiple lens materials with different refractive indices and dispersion properties. By cementing together lenses made of different materials (e.g., positive and negative lenses with complementary chromatic characteristics), the design achieves chromatic aberration correction within a compact, lightweight structure. This composite approach allows a small number of lenses to perform both stabilization and chromatic correction functions.
Solution Approach 2:
The invention carefully selects and adjusts optical parameters such as focal lengths, refractive indices, and Abbe numbers of the lenses in the stabilizing unit. By optimizing these parameters, the design achieves effective chromatic aberration suppression in a lightweight configuration. The specific focal length relationships (e.g., f3p/f3n ratios) are tuned to balance chromatic correction with compact size requirements.
3Object-generated harmful factors
If more lenses are added to the image stabilizing unit to suppress chromatic aberration, then chromatic aberration is corrected, but the unit becomes heavier and larger
Solution Approach 1:
Instead of adding more lenses, the invention uses composite lens design where each lens is made of specifically selected materials with complementary optical properties. The combination of positive and negative lenses with different dispersion characteristics achieves chromatic aberration correction through material properties rather than simply increasing the number of elements, thus avoiding additional weight.
Solution Approach 2:
The invention applies local quality by assigning specific optical characteristics to specific lenses within the stabilizing unit. Each lens is designed with particular refractive index and dispersion properties tailored to its position and function. This localized optimization allows chromatic aberration correction to be achieved through strategic material selection in key positions rather than uniformly increasing the complexity and weight of all lenses.
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 achieves high optical performance by suppressing chromatic aberration and eccentric coma while ensuring the image stabilizing unit remains compact and lightweight, facilitating efficient image stabilization.
Implementation Method 1
a resin layer Grep and a base lens arranged in this order from the object side to the image side, which are cemented together
Implementation Method 2
a resin layer and a lens cemented together
Data Source
AI summary
An optical system includes a movable unit movable in a direction eccentric to an optical axis. The movable unit includes a resin layer and a lens cemented together and satisfies a predetermined condition.