Non-Circular Incident Lens for Vehicle Door Pinch Detection
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Solution Overview
Problem
The existing vehicle glass raising/lowering device faces challenges in reducing the distance between light emitting elements and the optical axis of the lens, limiting the efficiency of infrared radiation reflection and increasing manufacturing costs due to the need for more light emitting elements or higher output elements to maintain light intensity.
Innovation Solution
The device incorporates a non-circular incident lens and arranges part of the light source unit in the cut-off region, allowing for a reduced distance between the light source unit and the optical axis while maintaining light intensity, using a microbead type retroreflective material for the detection line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between the light emitting elements and the optical axis of the lens is reduced, then the retroreflective material can perform more efficiently, but the distance cannot be reduced below the radius of the lens
Solution Approach 1:
The patent changes the lens shape from circular to non-circular (rectangular or square with cut corners), allowing the light emitting elements to be positioned in the corner regions. This dimensional reconfiguration enables the light emitting elements to be closer to the optical axis while maintaining sufficient light receiving area, as the light can enter the lens from the corner regions where the circular constraint no longer applies.
2Length of moving object
If the aperture of the lens is reduced to close the positions of light emitting elements and optical axis, then the positions can be closed, but the light receiving area becomes small and light intensity decreases
Solution Approach 1:
By changing the lens aperture shape from circular to non-circular with corner extensions, the patent increases the light receiving area in the corner regions where light emitting elements are positioned. This allows the light emitting elements to be placed closer to the optical axis while maintaining adequate light intensity, as the extended corner regions provide additional light entry paths without requiring a larger overall aperture.
Solution Approach 2:
The patent applies different functional qualities to different regions of the lens aperture. The corner regions of the non-circular aperture are specifically designed to receive light from the light emitting elements positioned near the optical axis, while the central regions maintain their traditional light receiving function. This local differentiation allows optimized light collection from each region for its specific purpose.
3Illumination intensity
If the number of light emitting elements is increased or high-output elements are used to secure light intensity, then light intensity is secured, but manufacturing cost increases
Solution Approach 1:
The non-circular lens aperture with corner extensions enables more efficient use of light by providing direct light entry paths from the light emitting elements positioned near the optical axis. This geometric optimization improves light collection efficiency, allowing the use of fewer light emitting elements or lower-output elements while maintaining sufficient light intensity for detection, thereby reducing manufacturing costs.
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 reduces the number of light emitting elements required or allows for the use of low-output elements, lowering manufacturing costs while ensuring effective detection of foreign objects and maintaining sufficient light intensity for the camera.
Implementation Method 1
a detection line 6 formed of a retroreflective material along at least a part of the frame portion 22; and a camera 7 comprising an incident lens 71a into which the non-visible light radiated from the light source unit 8 and reflected by the detection line 6 enters
Implementation Method 2
a light source unit 8 comprising a light emitting element 81 emitting non-visible light and radiating the non-visible light to the detection line 6
Data Source
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AI summary
This opening/closing body drive device 1 is provided with: a drive mechanism 4 for moving an opening/closing body 3; a control unit 5 for controlling the drive mechanism 4; a light source unit 8 for emitting non-visible light towards a detection line 6 which is formed from a microbead-type retroreflective material and along a frame part 25; and a camera 7 provided with an incident lens 71a on which the non-visible light reflected by the detection line 6 becomes incident. The incident lens 71a is formed into a non-circular shape by cutting at least one end in a direction orthogonal to the longitudinal direction of the detection line viewed from the camera. When the incident lens 71a is viewed from the direction of the optical axis thereof, at least a portion of the light source unit 8 is disposed in the cut section.