LiDAR Laser Emitting Circuit for Parasitic Light Emission Control
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Solution Overview
Problem
In one-driving-multiple emitting circuits for LiDAR, laser diodes often emit light at unexpected times, affecting measurement performance due to parasitic capacitance and current loops during the energy transfer stage.
Innovation Solution
A laser emitting circuit design featuring energy charging, transfer, and release circuits with a floating-ground diode and clamping diodes, where energy release switch elements are controlled to prevent parasitic capacitance-induced light emission, ensuring only intended laser diodes emit light during the energy release stage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a one-driving-multiple emitting circuit is used to drive multiple laser diodes, then the circuit complexity is reduced and energy efficiency is improved, but laser diodes may emit light at unexpected times due to parasitic capacitance and current loops
Solution Approach 1:
The patent introduces an energy transfer circuit as an intermediary between the energy charging circuit and multiple energy release circuits. This intermediary circuit includes an energy storage capacitor and floating-ground diode that isolates the direct connection between the charging circuit and laser diodes, preventing parasitic capacitance from causing unexpected light emission while still allowing efficient energy transfer to multiple lasers.
Solution Approach 2:
The patent divides the circuit into three distinct functional stages: energy charging circuit, energy transfer circuit, and multiple energy release circuits. Each stage is separated by specific circuit elements (floating-ground diodes, clamping diodes) that segment the current paths, preventing direct parasitic loops while maintaining the one-driving-multiple architecture's simplicity.
2Productivity
If energy is transferred to multiple laser diodes simultaneously, then the productivity and coverage of the LiDAR system is improved, but measurement precision deteriorates due to unexpected light emission during energy transfer stage
Solution Approach 1:
The patent implements a periodic three-stage operation cycle: energy charging stage, energy transfer stage, and energy release stage. During the energy transfer stage, clamping diodes are configured to prevent current flow to laser diodes, ensuring that light emission occurs only during the designated energy release stage. This periodic control maintains high productivity while eliminating measurement errors from unexpected emission.
3Speed
If parasitic capacitance in switch elements is present, then the switching speed and response time are improved, but harmful current loops are generated during energy transfer stage causing light emission
Solution Approach 1:
The patent acknowledges the presence of parasitic capacitance in switch elements but converts its harmful effect into a beneficial one. During the energy transfer stage, clamping diodes are configured to redirect parasitic capacitance current to ground rather than allowing it to flow through laser diodes. This approach maintains the fast switching speed provided by parasitic capacitance while preventing harmful current loops and unexpected light emission.
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
Prevents unexpected light emission from laser diodes during the energy transfer stage, thereby improving the measurement performance of LiDAR systems by ensuring controlled and timely light emission.
Implementation Method 1
the phenomenon that the laser diode emits light at an unexpected time may occur, which affects a performance of the LiDAR
Implementation Method 2
the energy transfer circuit includes an energy storage capacitor and a floating-ground diode, wherein a first terminal of the energy storage capacitor is connected to the energy charging circuit; the first terminal of the energy storage capacitor is connected to the energy release circuit; a second terminal of the energy storage capacitor is grounded by the floating-ground diode
Data Source
AI summary
The present application discloses a laser emitting circuit and a LiDAR. The laser emitting circuit includes an energy charging circuit, an energy transfer circuit, and a plurality of energy release circuits. The plurality of energy release circuits are connected in parallel. The energy charging circuit is connected to the energy transfer circuit to store electrical energy. The energy transfer circuit is connected to the energy charging circuit and the plurality of energy release circuits to transfer the electrical energy stored in the energy charging circuit to the energy transfer circuit. The energy transfer circuit includes an energy storage capacitor and a floating-ground diode. Each energy release circuit is configured to drive a laser diode to emit light by using the electrical energy stored in the energy transfer circuit, and the energy release circuit includes an energy release switch element, the laser diode, and a clamping diode.