Laser Driver Capacitor Segmentation for Fast Rise Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Measurement devices using the Time of Flight method for three-dimensional shape measurement require a reduction in the inductance of the electric current path to supply the driving current to the laser unit and a faster rise time for light emission, which is not effectively achieved with conventional capacitive elements.
Innovation Solution
A light-emitting device configuration that includes a low-equivalent series inductance (ESL) capacitor and a larger capacity, smaller mount area capacitor, which together supply the driving electric current to the laser unit, reducing the inductance and increasing the rising speed of the current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional capacitive element is used to supply driving current to the laser unit, then the device structure is simple, but the inductance of the electric current path is high and the rising speed of light emission is slow
Solution Approach 1:
The patent divides the capacitive element into two separate capacitors: a first capacitor with small equivalent series inductance and a second capacitor with large capacity. This segmentation allows each capacitor to fulfill its specific function optimally - the first capacitor provides fast current rise by minimizing inductance, while the second capacitor supplies sufficient energy by providing large capacity, thereby achieving fast rising light emission without excessive structural complexity
Solution Approach 2:
The patent transitions from a single-dimension solution (one capacitive element) to a multi-dimension solution by considering both inductance characteristics and capacity characteristics as separate dimensions. By selecting capacitors based on different dimensional criteria (ESL for the first capacitor, capacity for the second capacitor), the system achieves superior performance in both rising speed and energy supply capability
2Power
If a single capacitive element with large capacity is used, then the device can maintain light output of 2W to 4W, but the inductance is high and rise time is long
Solution Approach 1:
The patent segments the power supply function into two distinct capacitive elements: the first capacitor optimized for fast response (small ESL) and the second capacitor optimized for energy storage (large capacity). This segmentation enables the system to achieve both high power output and fast rise time, as the first capacitor provides immediate current surge while the second capacitor sustains the required power level
Solution Approach 2:
The patent applies parameter changes by selecting capacitors with specifically optimized electrical parameters - the first capacitor is selected for minimal equivalent series inductance to enable fast current rise, while the second capacitor is selected for large capacity to maintain high power output. This parameter-based selection resolves the contradiction between power level and rise time
3Speed
If a single capacitive element with small inductance is used, then the rising speed of current is fast, but the capacity is insufficient to maintain high light output
Solution Approach 1:
The patent segments the capacitive function into two specialized components: the first capacitor with small equivalent series inductance that enables fast current rising speed, and the second capacitor with large capacity that ensures sufficient energy supply for maintaining high light output. This functional segmentation allows each capacitor to excel at its specific task without compromise
Solution Approach 2:
The patent merges two capacitive elements with complementary characteristics into a unified power supply system. The first capacitor (small ESL) and second capacitor (large capacity) work together synergistically, where the first provides rapid current establishment and the second provides sustained energy supply, achieving both fast rising speed and high power output simultaneously
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 shortens the rise time of the driving electric current pulse, enhancing the measurement accuracy and reducing the device size, while maintaining a high light output of 2 W to 4 W.
Implementation Method 1
a first capacitive element and a second capacitive element that supply a driving electric current to the laser unit; wherein the first capacitive element has smaller equivalent series inductance than the second capacitive element
Data Source
AI summary
A light-emitting device includes a laser unit; and a first capacitive element and a second capacitive element that supply a driving electric current to the laser unit; wherein the first capacitive element has smaller equivalent series inductance than the second capacitive element, and the second capacitive element has a larger capacity and a smaller mount area than the first capacitive element.