Camera Module Infrared Filter Coating for Flare Reduction
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Solution Overview
Problem
Camera modules experience image quality degradation due to flare phenomena caused by diffusely reflected light being introduced to the image sensor, which is not effectively addressed by existing infrared filters fixed within the housing.
Innovation Solution
A camera module design featuring an infrared filter with a coating material applied to its surface to block diffusely reflected light, securely fixed to the housing using a UV adhesive, and strategically positioned to prevent light from reaching the image sensor, including protrusions and light transmissive parts with holes for UV curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an infrared filter is fixed within the housing of a camera module, then the infrared filter can be positioned to filter infrared light, but light having passed through the lens may be diffusely reflected to an inner wall of the housing and introduced to an image sensor, causing a flare phenomenon that degrades image quality
Solution Approach 1:
The patent applies a light-blocking coating to specific local areas of the infrared filter's rear surface, particularly at the edges and corners. This local quality enhancement blocks diffusely reflected light in critical zones while maintaining infrared transmission performance in the central light transmissive area, thereby preventing flare without compromising the infrared filtering function.
Solution Approach 2:
The infrared filter is constructed as a composite structure combining a light transmissive material (for infrared transmission) with a light-blocking coating material applied to its rear surface. This composite design enables the filter to simultaneously perform infrared light transmission and blockage of diffusely reflected visible light, resolving the contradiction between infrared filtering and flare prevention.
2Stability of the object's composition
If the infrared filter is securely fixed to the housing, then the filter remains stable during operation, but the bonding process and structure must not compromise image quality or allow light leakage
Solution Approach 1:
The light-blocking coating is strategically applied to the edges and corners of the infrared filter's rear surface where bonding occurs. This local treatment ensures that the coating does not interfere with the bonding process or light transmission through the filter, while still providing flare prevention. The bonding structure itself is designed to be localized, maintaining stability without creating obstacles that could cause light leakage.
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
Effectively prevents diffusely reflected light from degrading image quality and securely fixes the infrared filter within the housing, enhancing image clarity and module performance.
Implementation Method 1
an infrared filter with a coating material applied to a portion of one surface thereof so as to block diffusely reflected light
Implementation Method 2
The IR filter may be bonded to the housing by a UV adhesive
Data Source
AI summary
There is provided a camera module including a lens barrel including at least one lens disposed on an optical axis, a housing having the lens barrel disposed therein, and an infrared (IR) filter bonded to an inside of the housing and disposed below the lens barrel, wherein the IR filter has a coating material applied to a portion of one surface thereof so as to block diffusely reflected light.