Vehicular Camera Focus Testing With External Light Collimation
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Solution Overview
Problem
Traditional environmental testing for automotive cameras fails to effectively measure camera sharpness and defocus under varying temperature and humidity conditions.
Innovation Solution
A vehicular camera testing system using a light-collimating device outside an environmentally-controlled chamber projects a target within the chamber for the camera to capture, allowing real-time measurement of sharpness and defocus under controlled environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional environmental testing is used for automotive cameras, then the camera can be tested under varying temperature and humidity conditions, but the measurement precision of camera sharpness and defocus deteriorates
Solution Approach 1:
A light collimating device is introduced as an intermediary component between the test environment and the camera under test. This device projects a collimated light target that remains optically stable despite environmental variations, enabling precise focus measurements while maintaining environmental adaptability. The collimated light acts as a mediator that decouples the measurement reference from environmental disturbances.
Solution Approach 2:
The system changes the optical parameters of the test target by using a light collimating device to create a collimated light field with specific optical properties (parallel rays, defined divergence). This parameter change in the target's optical characteristics allows for accurate focus measurement independent of environmental temperature and humidity fluctuations.
2Measurement precision
If a light collimating device is used to project a target through a chamber window, then measurement precision of camera focus improves, but device complexity increases
Solution Approach 1:
The light collimating device serves as an intermediary that simplifies the overall measurement system by providing a stable optical reference. Rather than complex environmental controls for the target, a single collimating device mounted outside the chamber provides the necessary optical stability, reducing overall system complexity while improving measurement precision.
Solution Approach 2:
The testing system is segmented into distinct functional zones: the environmentally-controlled chamber for the camera under test, and the external light collimating device for target projection. This segmentation allows each component to be optimized independently, with the collimating device operating in a stable external environment while the camera experiences controlled environmental variations.
3Ease of operation
If the light collimating device is positioned exterior to the environmentally-controlled chamber, then the measurement system becomes easier to operate, but the illumination intensity at the camera may be reduced
Solution Approach 1:
The chamber window acts as an intermediary optical element that transmits the collimated light from the external source to the camera inside the chamber. This intermediary approach allows the light source to remain outside the controlled environment (simplifying operation) while still delivering adequate illumination through the window to the test camera.
Solution Approach 2:
The system compensates for potential illumination intensity reduction by adjusting parameters of the light collimating device, such as increasing source intensity or optimizing collimation geometry, to ensure sufficient light reaches the camera through the chamber window while maintaining ease of external operation.
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
Enables precise calibration and compensation for camera defocus and sharpness across varying environmental parameters, ensuring consistent imaging performance.
Implementation Method 1
positioned a light-collimating device exterior the environmentally-controlled chamber. With the light-collimating device operating to emit collimated light, collimated light emitted by the light-collimating device passes through the window of the environmentally-controlled chamber to project a target within the environmentally-controlled chamber
Data Source
AI summary
A method for testing a vehicular camera includes providing a vehicular camera and an environmentally-controlled chamber that has a window allowing visible light to pass into the interior of the chamber. A light-collimating device is provided exterior the environmentally-controlled chamber, and the vehicular camera is disposed within the interior of the environmentally-controlled chamber. Light emitted by the device passes through a window of the chamber to project a target within the chamber. Image data is captured with the vehicular camera that includes at least a portion of the projected target. Responsive to processing by an image processor of image data captured by the vehicular camera, a characteristic of the vehicular camera is estimated.