LED Projector Junction Temperature Control via Variable Drive Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic devices, such as LED projectors, operate at a fixed drive current and variable cooling, limiting performance at varying ambient temperatures, as the maximum junction temperature is used to calculate a constant input drive current, which restricts output brightness and does not maximize performance across different ambient conditions.
Innovation Solution
Implementing a variable power input to maintain a predetermined junction temperature independent of ambient temperature, allowing for increased brightness and performance by adjusting power to the display device, such as an LED projector, while using intelligent cooling techniques to control junction temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the drive current is increased to increase brightness, then the brightness of the display device is improved, but the junction temperature increases which reduces device lifetime
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed drive current to a variable drive current that is dynamically adjusted based on real-time temperature feedback. The controller continuously monitors the temperature of the light emitting element and adjusts the drive current accordingly, allowing the system to operate at higher currents (and thus higher brightness) when temperatures are low, while reducing current when temperatures rise to prevent damage, thereby resolving the contradiction between brightness and device lifetime
Solution Approach 2:
The patent implements feedback control by using a temperature sensor to monitor the junction temperature of the light emitting element and feeding this information back to the controller. The controller then adjusts the drive current based on this feedback signal, creating a closed-loop control system that automatically balances brightness output with thermal management, allowing maximum brightness when safe and preventing overheating-induced failure
2Reliability
If the drive current is reduced to maintain constant junction temperature, then the junction temperature is controlled, but the brightness and performance of the display device decreases
Solution Approach 1:
The system dynamically adjusts the drive current based on ambient temperature conditions rather than maintaining a fixed conservative current level. When ambient temperature is low, the controller allows higher drive currents that produce brighter display output. When ambient temperature rises, the controller reduces current to maintain safe junction temperatures. This dynamic adaptation resolves the contradiction by allowing high brightness when thermally safe and maintaining temperature control when necessary
Solution Approach 2:
The patent changes the operating parameters (drive current) based on environmental conditions (ambient temperature) and real-time state (junction temperature). By varying the drive current parameter in response to temperature measurements, the system optimizes both brightness and temperature control, avoiding the need to operate at a fixed low current that would ensure temperature safety but sacrifice performance
3Reliability
If active cooling devices are used to dissipate heat at high ambient temperatures, then the junction temperature is maintained, but power consumption increases and noise is generated
Solution Approach 1:
The patent extracts the active cooling mechanism from the thermal management strategy and replaces it with a preventive approach. Instead of using active cooling devices (fans, Peltier elements) to remove heat after it is generated, the system prevents excessive heat generation in the first place by dynamically limiting the drive current when temperatures approach unsafe levels. This eliminates or reduces the need for power-consuming active cooling while maintaining junction temperature control
Solution Approach 2:
The patent converts the potentially harmful effect of heat generation into a useful control mechanism. By monitoring temperature and using it as a feedback signal to adjust drive current, the system turns thermal conditions into a beneficial control parameter. This allows the display to operate at maximum brightness when thermally safe and automatically throttle performance when temperatures rise, eliminating the need for additional power-consuming cooling devices
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 approach enables increased display brightness at lower ambient temperatures and extends the life of electronic devices by maintaining a constant junction temperature, thereby optimizing performance and longevity.
Implementation Method 1
When light emitting diodes (LEDs) or solid state lasers are used for the illumination source
Implementation Method 2
the junction temperature of a semiconductor device is the temperature of the semiconductor junction where the semiconductor device generates a maximum amount of heat
Implementation Method 3
The manufacturer may also design sufficient cooling of the device to enable it to dissipate the junction temperature heat and operate safely at the maximum ambient temperature, whether by convection into the air or with the aid of cooling devices
Data Source
AI summary
Methods and apparatus are disclosed for maximizing performance of an electronic device, such as a display device. Aspects of the exemplary embodiments include operating the electronic device by adjusting power to the device to maintain a predetermined junction temperature of the device independent of the ambient temperature at which the device is operating.