Light Emitting Display Data Voltage Output Circuit Pre-Charging Reference Line
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current light emitting display devices face challenges in shortening sensing and compensation times due to limitations in source following processes during panel operation.
Innovation Solution
A light emitting display device and driving method that pre-charges a reference line of the display panel using a voltage output from data voltage output circuits, allowing for efficient sensing and compensation by applying pre-charge voltage and sensing voltage to sub-pixels, thereby reducing sensing time and compensation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If source following process is performed during sensing, then sensing operation can be completed, but sensing time and compensation time are extended
Solution Approach 1:
The patent applies preliminary action by pre-charging the reference line with a pre-charge voltage before the sensing operation begins. This prepares the reference line in advance so that when sensing occurs, the voltage difference between the reference line and data line is minimized, allowing the sensing operation to complete faster while maintaining accuracy. The pre-charge voltage is set to match expected data voltages, reducing the time needed for the sensing transistor to charge the sensing capacitor.
Solution Approach 2:
The patent changes the voltage parameter of the reference line dynamically by applying different pre-charge voltages corresponding to different data voltage levels (e.g., first pre-charge voltage for first data voltage, second pre-charge voltage for second data voltage). This parameter optimization reduces the charging time of the sensing capacitor during sensing operations, thereby shortening both sensing time and compensation time while maintaining sensing precision.
2Device complexity
If reference line is not pre-charged, then device operation is simpler, but sensing and compensation times are longer
Solution Approach 1:
The data voltage output circuits serve multiple functions: they output data voltages to data lines during normal display operation and output pre-charge voltages to the reference line during sensing operations. This multi-functionality allows the system to gain sensing time benefits without adding separate dedicated pre-charge circuitry, thus minimizing device complexity while achieving faster sensing and compensation.
3Loss of time
If pre-charge voltage is applied to reference line, then sensing time is shortened, but additional voltage output control is required
Solution Approach 1:
The system employs periodic action by alternately switching the data voltage output circuits between two operational modes: outputting data voltages during display periods and outputting pre-charge voltages during sensing periods. This time-division multiplexing approach allows the same circuits to perform different functions at different times, reducing the need for separate dedicated circuits and minimizing the complexity of voltage output control while achieving shortened sensing times.
Data Source
AI summary
A light emitting display device includes a display panel configured to display an image, and a data driver including a panel driving circuit and a panel sensing circuit, the panel driving circuit configured to drive the display panel, and the panel sensing circuit configured to sense the display panel. The data driver pre-charges a reference line of the display panel based on a voltage output from at least one of data voltage output circuits included in the panel driving circuit.