Optical Navigation Layout With Multi-Source Depth of Field Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional navigation devices have a limited depth of field due to the restricted width of the collimated light beam, which affects their operational range and adaptability to various surfaces.
Innovation Solution
The optical navigation device employs multiple light sources arranged at different longitudinal heights and transverse distances relative to the light sensor, forming distinct crossover regions within the field of view to increase the total depth of field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light source is used to form a collimated light beam, then the optical path is simplified, but the depth of field is limited due to the restricted beam width
Solution Approach 1:
The patent divides the single light source into multiple light sources (first light source and second light source) positioned at different locations. Each light source forms its own illumination light beam with a corresponding crossover region, allowing the depth of field to be extended by combining the overlapping regions of multiple beams while keeping individual optical paths relatively simple.
2Length of stationary object
If multiple light sources are arranged at different longitudinal heights and transverse distances, then the depth of field is increased, but the device complexity increases
Solution Approach 1:
The patent positions multiple light sources in both longitudinal and transverse dimensions relative to the light sensor. The first light source is arranged at a first longitudinal height and first transverse distance, while the second light source is arranged at a second longitudinal height and second transverse distance. This multi-dimensional arrangement creates overlapping crossover regions that extend the depth of field while distributing the complexity across spatial dimensions.
3Length of stationary object
If the light beam width is increased to extend depth of field, then the operational range is improved, but the beam control and precision are reduced
Solution Approach 1:
The patent merges multiple illumination light beams from different light sources to create an extended depth of field. Each individual beam maintains its own crossover region and control characteristics, while the combination of overlapping beams from the first and second light sources provides an extended operational range without sacrificing the precision control of individual beams.
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 enhances the operational depth of field, allowing the device to effectively capture diffuse reflection light from a wider range of surfaces, including tables, skin, and mouse pads, by extending the working range and improving adaptability.
Implementation Method 1
emission light of the first light source is refracted by the light directing member to propagate toward the light sensor after passing the light directing member
Implementation Method 2
receive diffuse reflection light of the first illumination light beam from a work surface
Data Source
AI summary
There is provided an optical navigation device including a substrate, a light sensor, a first light source, a second light source and a light directing member. The light sensor is arranged on the substrate and has a field of view (FOV) perpendicular to the substrate. The emission light of the first light source forms a first illumination light beam after passing the light directing member. The emission light of the second light source forms a second illumination light beam after passing the light directing member. A first crossover region of the first illumination light beam with the FOV is closer to the substrate than a second crossover region of the second illumination light beam with the FOV.