LED PN-Junction Temperature Measurement via Electrical Parameter Variation

The patent uses forward voltage as an intermediary parameter to indirectly measure the PN-junction temperature. Instead of directly measuring temperature, the method applies a constant current to the LED and measures the forward voltage, which has a known linear relationship with temperature. This intermediary measurement approach enables accurate PN-junction temperature detection without direct thermal contact or complex measurement systems.

The patent replaces conventional thermal measurement methods (such as thermocouples or thermal imaging) with an electrical measurement approach. By utilizing the electrical characteristic (forward voltage) of the LED itself as a temperature sensor, the method eliminates the need for external thermal sensing equipment and achieves non-contact, high-precision temperature measurement.

The patent makes the LED itself serve as the temperature sensor by utilizing its inherent forward voltage-temperature relationship. This self-service approach eliminates the need for external temperature sensors and multiple test setups for different operating conditions. The LED's own electrical characteristics provide temperature information across all operating conditions, significantly reducing measurement time while maintaining reliability.

The patent exploits the parameter change of forward voltage with temperature to enable temperature measurement. By monitoring how the forward voltage parameter changes under constant current conditions, the method can accurately determine temperature across various operating conditions without requiring separate measurements for each condition, thus saving development time while ensuring measurement reliability.