Optical Sensor Cover with Protruding Light Passage Surface
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Solution Overview
Problem
Optical sensors face issues with dirt accumulation and mechanical damage due to manufacturing tolerances, leading to impaired light transmission and object abrasion, which affects their reproducible optical properties and detection accuracy.
Innovation Solution
An optical cover with a cylindrical segment forming a light passage surface that protrudes beyond a non-transparent covering surface, featuring an edging design where the light passage surface is higher and lower than the edge, ensuring dirt accumulation on the covering surface and protecting the light passage surface from mechanical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the window is fitted exactly into the housing opening, then the optical transmission function is optimized, but manufacturing tolerances cause the window to be either set back (forming a recess) or offset forward (forming a protrusion)
Solution Approach 1:
The optical cover is divided into functionally distinct segments: a light passage surface segment for optical transmission and a covering surface segment for protection. This segmentation allows each part to be optimized for its specific function while accommodating manufacturing tolerances.
Solution Approach 2:
Different surfaces of the optical cover are given different properties: the light passage surface is transparent and smooth for optimal light transmission, while the covering surface is non-transparent and textured for dirt accumulation. This local differentiation resolves the contradiction by allowing the light passage area to maintain optical quality despite overall positioning variations.
2Ease of operation
If the window forms a protrusion beyond the housing outer wall, then the light passage is unobstructed, but objects to be detected experience abrasion leading to deposits on the window
Solution Approach 1:
The covering surface acts as an intermediary protective layer between the moving objects and the light passage surface. It absorbs the mechanical contact and abrasion, preventing direct damage to the optical surface while still allowing light transmission through the light passage surface.
Solution Approach 2:
The optical cover is segmented into a light passage surface and a covering surface, where the covering surface serves as a sacrificial protective layer that takes the abrasion and mechanical contact, protecting the underlying light passage surface from damage.
3Device complexity
If the window is set back forming a recess, then the housing structure is simplified, but dirt accumulates on the top of the window impairing light transmission
Solution Approach 1:
Instead of making the light passage surface recessed (which traps dirt), the invention inverts the approach by making the light passage surface protrude above the covering surface. This inversion ensures that dirt accumulates on the covering surface rather than on the light passage surface, maintaining optical transmission function.
Solution Approach 2:
The optical cover has different local geometries: the light passage surface protrudes to avoid dirt accumulation, while the covering surface extends back to provide structural support and dirt trapping. This local geometric differentiation resolves the contradiction between structural simplicity and dirt resistance.
4Use of energy by moving object
If the light passage surface is exposed, then light transmission is maximized, but the surface is vulnerable to mechanical damage and dirt accumulation
Solution Approach 1:
The optical cover is segmented into a light passage surface and a covering surface, allowing the light passage surface to remain exposed for optimal light transmission while the covering surface provides protective coverage for mechanical damage and dirt accumulation.
Solution Approach 2:
The covering surface serves as an intermediary protective layer that shields the light passage surface from mechanical damage and dirt, while the light passage surface remains accessible for optimal optical performance. The edging provides an additional intermediary barrier that objects must contact before reaching the light passage surface.
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 design effectively prevents dirt accumulation on the light passage surface and protects it from mechanical damage, maintaining optical functionality and accuracy while guiding light beams unhindered.
Implementation Method 1
the upper edge of which forms a light passage surface through which the light beams are guided
Implementation Method 2
a photoelectric element that receives light rays
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The optical sensor comprises a photoelectric element which is integrated in housing, where a light beam (3) is received and emitted. An optical covering (8) is superordinated to the photoelectric element, where the optical covering has a light permeating surface (14) which is enclosed by a covering surface (15). The beam of light is guided through the light permeating surface which is projected over the covering surface. An edge (16) is provided for projecting over the covering surface and the light permeating surface.