Internal Reflection Surface for Optical Navigation Sidelight Collimation
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Solution Overview
Problem
Conventional optical navigation devices face challenges in miniaturization due to the size and cost of LED assemblies, which also result in inefficiencies in light utilization and increased stray light interference, affecting performance.
Innovation Solution
The use of an internal reflection surface to collimate and redirect sidelight from a bare LED die, eliminating the need for a reflector cone and incorporating surface mount technology for assembly, thereby reducing device size and cost while enhancing light efficiency and minimizing stray light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a packaged LED with reflector cone is used, then light directionality is improved, but device size increases and cost increases
Solution Approach 1:
The patent extracts and removes the reflector cone from the LED package, using only a bare LED die. The internal reflection surface is integrated directly into the device housing rather than being part of the LED assembly, thereby eliminating the volume occupied by the reflector cone while maintaining light directionality through the internal reflection surface.
Solution Approach 2:
The patent merges the light source (bare LED die) directly with the internal reflection surface in the device housing. Instead of using a separate packaged LED with integrated reflector, the design combines the LED die placement with the internal reflection surface structure, reducing overall device volume while maintaining optical performance.
2Illumination intensity
If a packaged LED with reflector cone is used, then light directionality is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts and removes the expensive reflector cone component from the LED package. By using only a bare LED die and integrating the reflection function into the housing's internal reflection surface, the manufacturing cost is reduced while maintaining the light directionality function.
Solution Approach 2:
The patent replaces the expensive packaged LED with a cheaper bare LED die. The internal reflection surface is formed as an integral part of the housing structure rather than as a separate expensive component, reducing overall manufacturing cost while achieving the desired optical performance.
3Device complexity
If sidelight is not redirected, then device structure is simpler, but light efficiency decreases and stray light interference increases
Solution Approach 1:
The patent converts the previously harmful sidelight and stray light into beneficial directed light. The internal reflection surface is designed to redirect sidelight that would otherwise be wasted or cause interference into the desired optical path toward the work surface, improving light efficiency while maintaining structural simplicity.
Solution Approach 2:
The internal reflection surface acts as an intermediary element between the bare LED die and the work surface. It mediates the light paths by redirecting sidelight and stray light into the useful optical cone, improving light efficiency without requiring complex additional optical components.
4Device complexity
If sidelight is not redirected, then device structure is simpler, but stray light interference increases
Solution Approach 1:
The patent converts harmful stray light into beneficial directed light. The internal reflection surface is positioned and shaped to redirect stray light that would otherwise interfere with the sensor into the useful optical path, eliminating interference while maintaining structural simplicity.
Solution Approach 2:
The internal reflection surface serves as an intermediary that filters and redirects light paths. It acts as a passive optical element that prevents stray light from reaching the sensor directly, thereby reducing interference without requiring active control mechanisms or complex structures.
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 approach allows for a smaller, more economical optical navigation device with improved tracking precision and light efficiency, as a greater percentage of light is utilized and stray light is effectively managed, enabling accurate movement detection.
Implementation Method 1
an internal reflection surface to reflect and collimate sidelight from a light source
Implementation Method 2
The sidelight from the light source is reflected and collimated by an internal reflection surface towards a work surface
Data Source
AI summary
An optical navigation devices and methods that utilize an internal reflection surface to reflect and collimate sidelight from a light source are described. A light source is configured to emit light. The sidelight from the light source is reflected and collimated by an internal reflection surface towards a work surface. The light received by the sensor is used to measure movement of the optical navigation device relative to the work surface.