Transparent Substrate Optical Sensor Module for Cost Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of optical sensor modules limits their adoption in low-end applications, such as mass-market computer mice, despite their proven accuracy and reliability, due to the complexity and expense of manufacturing processes.
Innovation Solution
The optical sensor module is redesigned to utilize a diode laser emitting radiation at a wavelength between 960 and 980 nm, where the substrate is transparent, allowing for the use of both forward and backward emitted radiation and enabling a simpler, cheaper manufacturing process by integrating the photo diode structure into the VCSEL layers and using a discrete low-cost photo diode, along with a single converging means for multiple diode lasers and a transparent encapsulation for mechanical protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional VCSEL with wavelength around 850 nm is used, then the substrate is not transparent and additional complex manufacturing steps are required, but this increases manufacturing cost and complexity
Solution Approach 1:
The patent changes the laser wavelength parameter from conventional 850 nm to 980 nm, which transforms the substrate from opaque to transparent at the laser wavelength. This parameter change enables the substrate to be used as a window for the measuring beam, eliminating the need for complex additional manufacturing steps and reducing production costs while maintaining measurement accuracy
Solution Approach 2:
Instead of making the substrate opaque and adding separate components to handle the measuring beam path, the patent inverts the approach by making the substrate transparent and using it itself as the optical window. This inversion simplifies the structure and reduces manufacturing complexity
2Measurement precision
If multiple separate components are used for laser emission and detection, then measurement accuracy is maintained, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the substrate functions by making it serve multiple purposes: structural support, electrical isolation, and optical window for the measuring beam. This consolidation of functions into a single component reduces the total number of parts and simplifies the module structure while maintaining measurement precision
Solution Approach 2:
The substrate is designed with multi-functionality, acting simultaneously as the mechanical base, electrical insulator, and optical transmission window. This universal component approach reduces device complexity without compromising the accuracy of motion detection
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 significantly reduces production costs, making the optical sensor module price-competitive with lower-performance devices while maintaining high accuracy and reliability, and allows for broader applications in input devices and measuring apparatuses.
Implementation Method 1
at least one optical sensor including a diode laser having a laser cavity for generating a measuring beam
Implementation Method 2
converging means for converging the measuring beam in an action plane
Implementation Method 3
means for measuring the self-mixing effect, which means comprise a photo diode
Data Source
Figure 1~2
AI summary
The invention relates to an optical sensor module (1) for a measuring device. Said module comprises at least one optical sensor (2) including a diode laser (3) having a laser cavity for generating a measuring beam, the diode laser being attached to a substrate (12), converging means (5) (such as a lens). During measuring, such converging means (5) converges the measuring beam in an action plane and converges in the laser cavity the measuring beam radiation that has been back-scattered by an object to generate a self-mixing effect and means for measuring the self-mixing effect. Later means comprise a photo diode (4) and an associated signal processing circuitry. According to an essential aspect of the invention, that the diode laser (3) is configured to emit laser radiation of a wavelength for which the substrate (12) being attached to the diode laser (3) is transparent. This configuration leads to an essentially simple (and therefore cheap) sensor module.