Vehicle Camera Assembly Infrared Filter Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Incorporating an infrared filter into a camera assembly for automotive vehicles poses challenges in maintaining adequate image quality while adhering to size and cost constraints, as it increases the back focal distance and total track length, complicating the design and increasing costs when attempting to minimize these dimensions.
Innovation Solution
The camera assembly positions an infrared cut filter near the aperture stop with a plurality of lens elements between it and the sensor, utilizing only two aspherical surfaces and five lens elements to maintain optical performance, allowing for a shorter total track length and reduced back focal length, enabling a surface mount technique for securement to a circuit board substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an infrared filter is incorporated into the camera assembly, then image quality is improved, but the back focal distance and total track length increase
Solution Approach 1:
The patent inverts the conventional arrangement by placing the infrared filter at the front of the lens assembly rather than at the back near the sensor. This reversal allows the filter to be positioned where it can effectively block infrared radiation before it enters the optical path, while the optical design compensates to maintain a short back focal distance suitable for surface mount technology
Solution Approach 2:
The patent employs aspherical lens surfaces to change the optical parameters of the system. The aspherical surfaces allow for correction of optical aberrations introduced by the front-mounted infrared filter, enabling the system to achieve both short total track length and high image quality that would be difficult to obtain with conventional spherical lenses
2Manufacturing precision
If an infrared filter is incorporated into the camera assembly, then image quality is improved, but the total track length increases
Solution Approach 1:
The patent inverts the conventional arrangement by placing the infrared filter at the front of the lens assembly rather than at the back near the sensor. This reversal allows the filter to be positioned where it can effectively block infrared radiation before it enters the optical path, while the optical design compensates to maintain a short total track length suitable for surface mount technology
Solution Approach 2:
The patent integrates multiple components into a compact nested arrangement where the infrared filter is positioned within the lens housing, and the lens elements are closely spaced. This nesting approach minimizes the overall total track length while maintaining the functional separation needed for effective infrared filtering and high-quality image formation
3Length of moving object
If a large number of aspherical lens surfaces are introduced to reduce total track length, then size is reduced, but design complexity and cost increase
Solution Approach 1:
The patent employs aspherical lens surfaces to change the optical parameters of the system. The aspherical surfaces allow for correction of optical aberrations introduced by the front-mounted infrared filter, enabling the system to achieve both short total track length and high image quality that would be difficult to obtain with conventional spherical 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
This configuration achieves a compact camera design with improved image quality, reduced costs, and enhanced packaging, facilitating the integration of advanced driver assistance features by maintaining a shorter total track length and lower chief ray angle, while allowing for preassembly and increased reliability.
Implementation Method 1
An infrared cut filter 24 is situated to filter radiation as the radiation approaches the sensor 22
Implementation Method 2
A plurality of lens elements 26, 28 and 30 are situated between the infrared cut filter 24 and the sensor 22
Data Source
AI summary
An illustrative example camera assembly includes a sensor. An infrared cut filter is situated to filter radiation as the radiation approaches the sensor. A plurality of lens elements is situated between the sensor and the infrared cut filter.