Lens Unit Flange Design for Ghosting Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-performance camera systems, such as on-vehicle sensing cameras, ghosting and optical performance degradation occur due to flange parts in lens units, particularly when black coating is applied to the second lens and subsequent lenses, causing shifts in lens spacing and varying ink thickness, which compromises image quality.
Innovation Solution
A lens unit design featuring a plastic second lens with a flange part having a positioning face and a recessed first step part on its inner periphery, where black coating is applied to the first step part to reduce reflection and maintain optical axis alignment, along with additional features like ejector pin abutting parts and a light shielding sheet to prevent ghosting and optical degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If black coating is applied to the flange parts of the second lens and subsequent lenses to suppress ghosting, then ghosting is reduced, but lens spacing shifts and optical performance degrades
Solution Approach 1:
The flange part is divided into multiple surfaces: the first surface (outer peripheral side) receives black coating to suppress ghosting, while the second surface (inner peripheral side) remains uncoated to maintain precise lens spacing. This segmentation allows each surface to fulfill its specific function without compromising the other.
Solution Approach 2:
Black coating is applied selectively only to the first surface of the flange part rather than the entire flange structure. This localized application ensures that ghosting is suppressed where necessary (on the outer peripheral side) while preserving optical performance in critical areas (inner peripheral side facing the lens face).
2Object-affected harmful factors
If black coating is applied to the flange part to reduce reflection, then inner face reflectance is reduced, but coating thickness variation occurs
Solution Approach 1:
The flange part is divided into multiple surfaces with different treatments. The first surface (outer peripheral side) is coated with black paint to reduce reflection, while the second surface (inner peripheral side) remains uncoated. This segmentation eliminates the need for uniform coating across the entire flange, avoiding thickness variation issues.
Solution Approach 2:
Black coating is applied selectively only to the first surface of the flange part where reflection needs to be reduced. This localized approach avoids the manufacturing variability inherent in coating entire surfaces, as the coating is applied only where necessary for ghosting suppression.
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 design effectively suppresses ghosting and maintains optical performance by reducing inner face reflectance and stabilizing ink application, preventing lens position changes due to coating thickness and ensuring precise alignment and image quality.
Implementation Method 1
black coating is applied to the first step part. A boundary surface between the image side flange face and air which may be a cause of reflection is eliminated and thus, the inner face reflectance can be reduced.
Data Source
AI summary
Provided is a lens unit. A second lens is provided with a flange surface section that surrounds a lens surface. An image-side flange surface has an image-side flange surface inner-circumferential section which is shaped like a ring-shaped groove, and also has a ring-shaped image-side flange surface outer-circumferential section formed to the outside of the inner-circumferential section. The image-side flange surface inner-outer circumferential section is coated with black ink. The image-side flange surface outer-circumferential section is provided with boss-shaped positioning surface at six equidistant locations along the outer circumference. Ejector pin contact sections are formed between adjacent positioning surface, and said contact sections contact the ejector pins at the time of separation from the mold during resin molding.