AMOLED Pixel Circuit Short Circuit Detection and Control

The patent implements a preliminary detection mechanism that checks for short circuits before the OLED pixel operates. The detection circuit activates during the non-lighting phase to identify potential short circuits in the thin film layers between anode and cathode, preventing defective pixels from being activated. This preliminary action allows the system to catch defects early without waiting for actual failure during operation.

The patent introduces an intermediary detection circuit as a mediator between the driving circuit and the OLED pixel. This intermediate layer includes detection transistors and capacitors that monitor the electrical state of the pixel, specifically detecting voltage changes that indicate short circuits. The intermediary circuit translates physical defects into detectable electrical signals without directly interfering with the OLED's light-emitting function.

The patent enables the pixel circuit to perform self-detection and self-protection functions. The detection circuit is integrated within the pixel itself, allowing it to automatically identify its own defects without external intervention. When a short circuit is detected, the circuit automatically activates the light emitting control device to prevent current flow, effectively isolating the defective pixel without requiring external laser ablation equipment or complex post-processing steps.

The patent implements a feedback mechanism where the detection circuit continuously monitors the pixel's electrical state and provides feedback to the light emitting control device. When the detection circuit identifies a short circuit condition through voltage threshold comparisons, it sends feedback signals that trigger the control device to activate, thereby preventing current flow through the defective pixel. This closed-loop feedback system eliminates defective pixels dynamically without requiring complex manufacturing interventions.

The patent implements periodic detection by activating the detection circuit only during specific phases of the OLED operation cycle. The detection transistor is turned on during the non-lighting phase when the pixel is not emitting light, allowing for accurate short circuit detection without continuous power consumption. During the lighting phase, the detection circuit remains inactive, significantly reducing overall power consumption while maintaining detection capability at critical moments.

The detection operation is performed preliminarily during the non-lighting phase before the pixel activates for light emission. This timing strategy allows the detection circuit to check for short circuits when the pixel is in a known stable state, ensuring accurate detection. By conducting detection preliminarily rather than continuously, the system achieves high measurement precision only when needed, avoiding unnecessary power consumption during active light-emitting periods.