Vehicular Camera Hood Rib Angles for Light Suppression
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Solution Overview
Problem
Existing vehicular camera apparatuses struggle to effectively suppress extraneous light from entering the lens, particularly from the upper side, due to constraints in plastic injection molding that result in ribs with perpendicular or obtuse angles, leading to insufficient light blocking.
Innovation Solution
A vehicular camera apparatus with a hood featuring a rib structure and hole structure, where the ribs are inclined forward with acute and obtuse angles respectively, and holes are formed in the bottom wall to block extraneous light from both upper and lower sides, allowing for effective light suppression during resin molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ribs are formed by plastic injection molding with perpendicular or obtuse angles to the bottom wall, then the hood can be easily manufactured, but extraneous light from the upper side cannot be sufficiently suppressed
Solution Approach 1:
The patent changes the geometric parameters of the ribs by inclining the front surface at an acute angle (30-60 degrees) relative to the bottom wall, rather than using perpendicular or obtuse angles. This parameter change enables the ribs to effectively block reflected extraneous light from entering the lens while remaining compatible with plastic injection molding processes.
Solution Approach 2:
The patent introduces asymmetric rib structures where the front surface has a different angle (acute angle) compared to the rear surface. This asymmetry is specifically designed to block light paths from the upper side that would otherwise reflect into the lens, while maintaining manufacturing feasibility through injection molding.
2Object-affected harmful factors
If ribs are inclined forward with acute angles to block extraneous light, then light suppression is improved, but the molding process becomes difficult due to mold extraction constraints
Solution Approach 1:
The patent resolves the mold extraction problem by introducing holes through the bottom wall in the optical axis direction. These holes provide an additional dimensional path for mold extraction, allowing the inclined ribs to be formed without compromising manufacturability. The holes enable the lower mold to be extracted along the optical axis while the upper mold extracts in the opposite direction.
Solution Approach 2:
The patent segments the hood structure by introducing holes through the bottom wall, dividing the solid structure into regions separated by these openings. This segmentation allows independent mold extraction paths and enables the formation of inclined ribs that would otherwise be impossible to manufacture with conventional single-direction extraction.
3Shape
If holes are added to the bottom wall for mold extraction, then inclined ribs can be formed, but the hood structure becomes more complex
Solution Approach 1:
The holes in the bottom wall serve multiple functions: they enable mold extraction during manufacturing, allow inclined rib formation for light blocking, and maintain structural integrity of the hood. This multi-functionality reduces the need for additional separate components and minimizes overall structural complexity.
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 forward-inclined ribs and holes in the hood configuration effectively block extraneous light from entering the lens, improving light suppression compared to traditional designs without holes, while enabling the formation of inclined ribs during molding.
Implementation Method 1
when extraneous light enters any of the holes of the hood from the upper side and is reflected by, for example, the camera case, the reflected extraneous light is blocked, by the front surface of the rib that is located immediately backward of the reflection point, from entering the lens
Implementation Method 2
The hood may be formed of resin by molding using a pair of lower and upper dies. The passages through which the lower mold is pulled out to the lower side make up the holes formed in the bottom wall
Data Source
AI summary
A vehicular camera apparatus includes a lens and a hood provided below the lens. The hood includes a rib structure and a hole structure. The rib structure is constituted of ribs that each protrude upward from a bottom wall of the hood and are arrayed in an optical axis direction of the lens. Each of the ribs has a front surface on the opposite side to the lens and a rear surface on the lens side. The front surface makes an acute angle with an imaginary plane that contains an upper surface of the bottom wall. The rear surface makes an obtuse angle with the imaginary plane. The hole structure is constituted of holes formed in the bottom wall. Each of the holes is formed along a corresponding one of the ribs and includes, at least, a projection of the front surface of the corresponding rib on the imaginary plane.