Laser Diode Power Control for Overheating and Brightness Balance

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Solution Overview

Problem

Existing laser devices face challenges in managing thermal management to prevent undue heating and maintain optimal performance across varying environmental temperatures.

Innovation Solution

A laser device with a temperature sensor and controller that reduces operating power of the laser diode when internal temperature reaches a threshold, with periodic temperature checks to adjust power levels further if necessary, ensuring gradual power reduction based on temperature differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the operating power of the laser diode is maintained at high levels, then the brightness and performance of the laser beam is improved, but the internal temperature of the device increases leading to overheating and reduced reliability

Engineering Contradiction:
Improvelaser beam brightnessVSAvoidinternal temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent implements dynamic power adjustment by continuously monitoring the internal temperature and adjusting the laser diode's operating power in real-time. When the temperature reaches a threshold, the controller automatically reduces the power level, creating a dynamic balance between maintaining brightness and preventing overheating.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs a feedback mechanism where a temperature sensor continuously measures the internal temperature and feeds this information back to the controller. The controller then adjusts the laser diode power accordingly, forming a closed-loop control system that prevents overheating while maintaining optimal performance.

Inventive Principle:
Principle #23Feedback

2Temperature

If the operating power of the laser diode is reduced to prevent overheating, then the temperature control is improved, but the brightness and performance of the laser beam deteriorates

Engineering Contradiction:
Improveinternal temperatureVSAvoidlaser beam brightness
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The system dynamically adjusts power levels based on real-time temperature conditions rather than maintaining a fixed reduced power level. This allows the laser to operate at full brightness when temperatures are acceptable and only reduces power when necessary, minimizing performance degradation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller changes the operating parameters (power level) of the laser diode based on temperature thresholds. By adjusting the duty cycle or current levels, the system modifies the operational parameters to balance temperature control with maintaining adequate brightness for the application.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If continuous monitoring of temperature is implemented, then the thermal management is improved, but the energy consumption and device complexity increases

Engineering Contradiction:
Improvetemperature controlVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The temperature monitoring is implemented periodically at specific time intervals rather than continuously. The controller checks the temperature at predetermined intervals and adjusts power only when necessary, reducing energy consumption compared to continuous monitoring while still maintaining effective thermal management.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the device's own operational characteristics (temperature rise during operation) to trigger monitoring and adjustment. The temperature sensor and controller work together as an integrated self-regulating system that only activates when temperature thresholds are approached, minimizing additional energy consumption.

Inventive Principle:
Principle #25Self-service

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

Effectively prevents overheating by dynamically adjusting power to maintain optimal operation and brightness, extending the device's usable lifespan and reliability.

Implementation Method 1

a temperature sensor for detecting a temperature Ti assigned to the laser device, such as the internal temperature of the laser device

Methodology Applied
Scientific EffectThermal energy detection: Thermal Radiation

Implementation Method 2

at least one laser diode for emitting a laser beam

Methodology Applied
Scientific EffectLaser emission: Laser

Implementation Method 3

at least one laser diode for emitting a laser beam

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 4

the operating power Pb of the laser diode is reduced to a reduced operating power Pred when the detected temperature Ti reaches a temperature threshold value Ts

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4617623A1Laser apparatus and method for controlling the same
Publication Date: 2025.09.17 STABILA MESSGERATE GUSTAV ULLRICH GMBH & CO KG
  • EP4617623A1 patent drawingFigure 1
  • EP4617623A1 patent drawingFigure 2
  • EP4617623A1 patent drawingFigure 3

AI summary

The invention relates to a laser device (10) and a method for controlling such a device. The laser device (10) comprises at least one laser diode (14) for emitting a laser beam (16, 20), a laser diode controller (24) for controlling at least the operation of the laser diode (14), and a temperature sensor (32) for detecting a temperature Ti associated with the laser device (10), such as the internal temperature of the laser leveling tool. The laser diode controller (24) is configured to operate the at least one laser diode (14) at an operating power Pb and to reduce the operating power Pb of the laser diode (14) to a reduced operating power Pred when the detected temperature Ti reaches a temperature threshold value Ts.In order to operate the at least one laser diode at an optimal operating point which does not lead to undue heating, it is provided that the laser diode control (24) is configured such that after reducing the operating power Pb, the temperature Ti is compared with the temperature threshold value Ts at time intervals Δt and the reduced operating power Pred of the laser diode (14) is further reduced if the temperature Ti is greater than the temperature threshold value Ts upon comparison.