Display Panel Mobility Correction Circuit with Independent Switch Control
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Solution Overview
Problem
Wiring delays in active-matrix organic EL display devices cause variations in the mobility correction period, leading to inconsistent luminance across pixels, especially when displaying different shades of gray, due to changes in signal voltage and wiring delays affecting the timing of mobility correction.
Innovation Solution
A display panel device with a luminescence element, capacitors, and drivers, where the mobility correction is precisely controlled by separate switches for the start and end of the discharge current, ensuring consistent mobility correction across all shades of gray by controlling the switches independently of the signal voltage supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate switches are added for controlling mobility correction, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The pixel circuit is divided into distinct functional modules: a first switch for controlling signal voltage supply to the capacitor, and a second switch for controlling the discharge current path. This segmentation allows independent optimization of each switch's timing and function, enabling precise control over the mobility correction period without requiring complex integrated control mechanisms.
Solution Approach 2:
The patent implements dynamic control of the mobility correction period by independently timing the first and second switches. The first switch is activated at a first timing to supply signal voltage, while the second switch is activated at a second timing (different from the first timing) to enable discharge current. This dynamic, asymmetric switching approach allows the correction period to be precisely adjusted according to signal voltage changes, improving manufacturing precision while maintaining manageable circuit complexity through dedicated switch functions.
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 reduces variations in the mobility correction period, resulting in more consistent and stable luminance across the display panel, effectively suppressing the impact of wiring delays and ensuring precise control over luminescence intensity.
Implementation Method 1
a capacitor for holding a voltage
Implementation Method 2
Image display devices using organic electro-luminescence (EL) elements are known as image display devices using current-driven luminescence elements
Data Source
AI summary
A display panel device includes: a luminescence element; a capacitor including first and second capacitor electrodes; a driver having a gate connected to the first capacitor electrode for allowing a drain current to flow through the luminescence element; a first switch switchably interconnecting a data line and the first capacitor electrode for supplying a signal voltage to the capacitor; a second switch switchably interconnecting a source of the driver and the second capacitor electrode; and a controller. The controller is configured to: turn ON the first switch while the second switch is ON to supply the signal voltage to the first capacitor electrode and flow a current between the source of the driver and the second capacitor electrode; and, after predetermined time period, turn OFF the second switch to cause non-conduction between the source of the driver and the second capacitor electrode.