LED Failure Detection via Voltage Sampling
Solution Overview
Problem
Existing LED failure detection methods are inadequate for timely identification of failed LED units in lighting and display applications, leading to potential malfunctions and inefficiencies.
Innovation Solution
A light emitting diode (LED) failure detecting device that includes a driving circuit and a determining circuit, which drives LED units and generates a determination output based on voltage differences between sample points to indicate whether an LED unit has failed, allowing for timely replacement of faulty LEDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing LED failure detection methods are used, then the system can operate continuously, but LED failures cannot be identified timely leading to malfunctions
Solution Approach 1:
The patent applies preliminary action by continuously monitoring LED voltage characteristics before complete failure occurs. The detection circuit samples voltage at multiple time points during the LED operating cycle and compares these samples to detect deviations that indicate impending or current failure, enabling early intervention before system malfunction.
Solution Approach 2:
The patent implements feedback by creating a closed-loop detection system that continuously monitors LED voltage, compares sampled values against reference thresholds, and provides failure status information back to the control system. This feedback mechanism enables real-time detection and response to LED failures, maintaining system reliability.
2Reliability
If a detection device is added to monitor LED units, then LED failures can be detected, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing a detection circuit that can monitor multiple LED units through a matrix configuration of scan lines and data lines. The same detection circuitry is reused across all LED units in the display, allowing a single multi-functional device to provide failure detection for the entire LED array rather than requiring separate detection circuits for each LED.
Solution Approach 2:
The patent implements self-service by having the LED display system's existing driving circuitry simultaneously perform both its primary function of driving LEDs and its secondary function of detecting LED failures. The scan lines and data lines used for LED control are also utilized for voltage sampling and failure detection, eliminating the need for completely separate dedicated detection hardware.
Data Source
AI summary
A light emitting diode (LED) failure detecting device is operatively associated with an LED array, and includes a driving circuit and a determining circuit The driving circuit drives LED units of the LED array through scan lines and data lines of the LED array in such a way that a current flows through one of the LED units. The determining circuit selects a voltage at the data line that is coupled to said one of the LED units, and generates, based on a difference between a first sample voltage that is related to at least the selected voltage at a first time point and a second sample voltage that is related to at least the selected voltage at a second time point, a determination output indicating whether said one of the LED units is determined to have failed.