Solid Light Source Thermal Management for Red Laser Diode COD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Red laser diodes (LDs) in image projection systems are prone to catastrophic optical damage (COD) when the temperature is lower, leading to malfunction and heat distribution issues among adjacent LDs, causing normal LDs to also malfunction.
Innovation Solution
A light source apparatus with a first and second solid light source, where the second light source emits heat and light with a different wavelength, and a controller that gradually increases the drive current of the second light source to prevent COD by maintaining the first light source's operation and ensuring the second light source reaches a temperature that prevents COD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drive current of the second solid light source (red LD) is increased quickly to achieve full brightness, then the productivity is improved, but the reliability deteriorates due to COD occurrence at low temperatures
Solution Approach 1:
The patent applies preliminary action by turning on the first solid light source (blue LD) before the second solid light source (red LD). The blue LD is activated first to generate heat that raises the temperature of the red LD, creating favorable thermal conditions before the red LD is turned on. This preliminary heating action prevents COD when the red LD is subsequently activated, as the temperature is already sufficient to avoid catastrophic optical damage.
Solution Approach 2:
The patent implements periodic action through staged drive current increase for the second solid light source. Instead of immediately applying full drive current, the controller increases the drive current in stages: first to a preliminary value, waits for temperature stabilization, then increases to the target value. This periodic, staged approach balances productivity and reliability by allowing thermal equilibrium at each stage.
2Reliability
If the drive current of the second solid light source is increased slowly to prevent COD, then the reliability is improved, but the productivity deteriorates due to delayed full brightness
Solution Approach 1:
The blue LD performs preliminary heating action before the red LD is activated. This preliminary thermal preparation allows the red LD to reach full brightness faster because the thermal ramp-up period is eliminated. The system achieves both high reliability (by preventing COD through pre-heating) and high productivity (by allowing immediate full-power operation after the brief preliminary phase).
Solution Approach 2:
The first solid light source (blue LD) acts as an intermediary that transfers thermal energy to the second solid light source (red LD). This intermediary heating mechanism allows indirect temperature control of the red LD without directly applying high drive current initially, thus preventing COD while enabling faster subsequent brightness achievement.
3Productivity
If multiple red LDs are operated simultaneously to increase output, then the productivity is improved, but the reliability deteriorates due to heat distribution issues and COD in adjacent LDs
Solution Approach 1:
The patent applies preliminary action by activating one red LD at a time in a predetermined sequence rather than simultaneously. The first red LD is turned on and allowed to stabilize thermally before the second red LD is activated. This staged activation ensures that each LD reaches appropriate temperature before full operation, preventing COD while eventually achieving high total output through sequential operation of multiple LDs.
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 solution effectively suppresses COD in the red LDs by ensuring they operate within a temperature range that prevents damage, maintaining the functionality of both the red and blue LDs in image projection systems.
Implementation Method 1
a first solid light source (5bc), and a second solid light source (5rd) arranged to transfer heat generated when the first solid light source is turned on
Implementation Method 2
a second solid light source configured to emit light with a wavelength different from that from the first solid light source
Data Source
AI summary
A light source apparatus includes a first solid light source, a second solid light source configured to emit light with a wavelength different from that from the first solid light source, and a controller configured to control turning on of the first and second solid light sources. The controller turns on the second solid light source while maintaining turning on the first solid light source after turning on the first solid light source.