VCSEL Array Driver Circuit for Fast, Equalized Optical Pulses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR systems face challenges in emitting high power optical pulses with well-defined origins in time and are often bulky, limiting their miniaturization and performance.
Innovation Solution
A driver circuit for an array of optical emitters, comprising a one-dimensional or two-dimensional array of VCSELs, capacitive elements, and a common voltage booster circuit with inductive elements, switches, and switches to control charging and discharging of capacitive elements, enabling high-speed optical pulses with fast rise times and equalized peak optical powers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional LIDAR systems use high power optical pulses for distance measurement, then measurement range is improved, but system size becomes bulky
Solution Approach 1:
The patent segments the optical emitter array into multiple independently addressable elements arranged in rows and columns. Each element can be individually controlled to emit optical pulses, allowing the system to achieve high power output through selective activation of multiple segments rather than requiring a single large emitter, thus reducing overall system size while maintaining measurement range.
Solution Approach 2:
The driver circuit is designed to universally control multiple optical emitters through a standardized switching mechanism. The same driver circuitry and control logic can address any emitter in the array by selecting different row and column combinations, enabling the system to achieve various power levels and beam patterns using identical hardware components, thereby reducing system complexity and size.
2Measurement precision
If LIDAR systems emit high power optical pulses, then distance range finding capability is improved, but power consumption increases
Solution Approach 1:
The system activates only the necessary number of optical emitters required to achieve the desired measurement range and resolution, rather than operating all emitters continuously. By selectively enabling only the minimum needed emitters for each measurement task, the system achieves adequate power output for distance range finding while significantly reducing overall power consumption compared to full-array operation.
Solution Approach 2:
The optical emitters operate in periodic pulsed mode rather than continuous operation. Each emitter emits high power optical pulses at specific time intervals, allowing the system to accumulate sufficient energy for accurate distance measurement during each pulse while consuming minimal power during the off periods between pulses.
3Volume of moving object
If LIDAR systems use array of optical emitters for miniaturization, then system size is reduced, but control complexity of individual emitters increases
Solution Approach 1:
The patent merges the control functions for multiple optical emitters into a single integrated driver circuit. By combining the control signals for rows and columns and using a switching matrix architecture, the circuit can selectively activate any individual emitter or group of emitters through coordinated switching, thereby reducing the number of separate control circuits needed and simplifying the overall control architecture despite the large number of emitters.
Solution Approach 2:
The switching matrix acts as an intermediary between the control signals and the optical emitters. Instead of directly connecting each control signal to each emitter, the switching matrix mediates the connection by routing control signals through row and column switches, enabling individual emitter selection with minimal control wiring and reduced circuit complexity.
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
The driver circuit facilitates miniaturization and improves LIDAR system performance by producing high-speed optical pulses with fast rise times and equalized peak optical powers, enhancing distance range finding and resolution while reducing power consumption.
Implementation Method 1
an inductive element; a first switch having an open state and a closed state, where the first switch in the closed state is to cause a charging of the inductive element, and where the first switch transitioning from the closed state to the open state is to cause a discharging of the inductive element
Implementation Method 2
a plurality of capacitive elements connected to respective VCSELs of the array of VCSELs
Data Source
AI summary
In some implementations, a controller may cause a first switch of a driver circuit to transition from an open state to a closed state to charge an inductive element of the driver circuit. The controller may cause the first switch to transition from the closed state to the open state to discharge the inductive element. The controller may cause a second switch of the driver circuit to transition from an open state to a closed state to select a capacitive element to be charged by discharging the inductive element. The controller may cause a third switch of the driver circuit to transition from an open state to a closed state to discharge the selected capacitive element to provide an electrical pulse to an optical emitter, of an array of optical emitters of the driver circuit, that is connected to the selected capacitive element.