Optical Unit Hydrophobic Casing for Actuator Protection
Solution Overview
Problem
Existing optical units face issues with foreign matter, such as raindrops or dust, adhering to light-transmitting elements, which can cause failure of the actuator driving the light-transmitting element to rotate, as the rotation process creates a space where foreign matter can enter and cause mechanical failures.
Innovation Solution
The optical unit incorporates a hydrophobic region on the casing adjacent to the light transmitter with a contact angle of droplets equal to or greater than a predetermined angle, preventing foreign matter from entering the space between the light transmitter and the casing, and a hydrophilic region outside the hydrophobic region to facilitate the flow of foreign matter away from the space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the light-transmitting element is driven to rotate relative to the casing to remove foreign matter, then foreign matter adhering to the light-transmitting element can be removed, but a space is formed between the light-transmitting element and the casing where foreign matter can enter and cause actuator failure
Solution Approach 1:
The patent applies local quality by creating a hydrophobic region with a specific contact angle (≥90 degrees) on the inner surface of the casing at the location adjacent to the light-transmitting element. This localized modification of surface properties prevents foreign matter from entering the space between the light-transmitting element and casing, while maintaining the rotational movement function for foreign matter removal from the optical surface.
Solution Approach 2:
The patent changes the surface parameter (contact angle) of the casing inner surface to create a hydrophobic region. By modifying the contact angle parameter to be 90 degrees or more, the surface properties are changed to repel water and foreign matter, preventing them from entering the critical space around the light-transmitting element during rotation.
2Stability of the object's composition
If the light-transmitting element is securely fastened to the housing, then the structure is stable, but no space is available for foreign matter removal through rotation
Solution Approach 1:
The patent applies local quality by creating a hydrophobic region with a specific contact angle (≥90 degrees) on the inner surface of the casing at the location adjacent to the light-transmitting element. This localized modification of surface properties prevents foreign matter from entering the space between the light-transmitting element and casing, while maintaining the rotational movement function for foreign matter removal from the optical surface.
Solution Approach 2:
The patent changes the surface parameter (contact angle) of the casing inner surface to create a hydrophobic region. By modifying the contact angle parameter to be 90 degrees or more, the surface properties are changed to repel water and foreign matter, preventing them from entering the critical space around the light-transmitting element during rotation.
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 effectively prevents foreign matter from entering the space between the light transmitter and the casing, thereby preventing actuator failure and ensuring clear images are obtained by the optical sensor.
Implementation Method 1
A first region on the casing adjacent to an outer edge of the light transmitter with the space interposed between the casing and the outer edge of the light transmitter is a hydrophobic region where a contact angle of a droplet is equal to or larger than a predetermined angle
Data Source
AI summary
An optical unit includes an optical sensor, a protective cover disposed in a direction of view from the optical sensor, an actuator to drive the protective cover, and a casing including a space between the casing and the protective cover and to which the optical sensor and the protective cover are attached. A first region on the casing adjacent to an outer edge of the protective cover with the space interposed between the casing and the outer edge of the protective cover is a hydrophobic region where a contact angle of a droplet is equal to or larger than a predetermined angle.