Scan Driver Signal Timing for OLED Step Efficiency and Ghosting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices, particularly OLEDs, face challenges in maintaining display quality, especially in moving images due to step efficiency issues and text ghost phenomena in static images, which are not adequately addressed by existing technologies.
Innovation Solution
A display device and method that utilize a scan driver to generate specific scan signals with turning-on voltages for multiple horizontal periods in moving image mode and a single period in static image mode, improving step efficiency and eliminating text ghost phenomena by adjusting the timing and duration of scan signals based on image modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional scan signal with turning-on voltage for a single horizontal period is used, then power consumption is reduced, but step efficiency deteriorates in moving image mode
Solution Approach 1:
The scan driver dynamically adjusts the duration of the scan signal's turning-on voltage based on the image mode. In moving image mode, the turning-on voltage is maintained for multiple horizontal periods (e.g., 2 or more) to improve step efficiency, while in static image mode, it is limited to a single horizontal period to reduce power consumption. This dynamic adaptation resolves the contradiction between power consumption and step efficiency.
Solution Approach 2:
The invention changes the temporal parameter of the scan signal by extending the duration of the turning-on voltage from a single horizontal period to multiple horizontal periods in moving image mode. This parameter change improves step efficiency without permanently increasing power consumption, as the duration is adjusted based on the image mode being displayed.
2Productivity
If a scan signal with extended turning-on voltage duration is used, then step efficiency is improved, but text ghost phenomena occur in static image mode
Solution Approach 1:
The scan driver dynamically adjusts the scan signal duration based on image mode detection. When static image mode is detected, the turning-on voltage is limited to a single horizontal period, which prevents text ghost phenomena. When moving image mode is detected, the duration is extended to multiple horizontal periods to improve step efficiency. This dynamic control eliminates the harmful effect in static mode while maintaining the benefit in moving mode.
Solution Approach 2:
The invention applies different scan signal characteristics to different operating conditions (image modes). The scan signal has extended duration quality when moving images are displayed, and normal duration quality when static images are displayed. This localized adaptation of signal properties prevents text ghost phenomena in static images while maintaining step efficiency in moving images.
3Productivity
If the scan signal is adjusted for moving image mode, then step efficiency is improved, but display quality deteriorates in static image mode
Solution Approach 1:
The scan driver dynamically adapts the scan signal characteristics to match the image mode. In static image mode, the scan signal uses the conventional single-horizontal-period duration, ensuring high display quality without artifacts. In moving image mode, the duration is extended to improve step efficiency. This dynamic adaptation ensures optimal display quality in both modes without compromise.
Solution Approach 2:
The invention changes the temporal parameter of the scan signal based on image mode. By extending the turning-on voltage duration only when moving images are displayed, the system improves step efficiency without degrading static image display quality. The parameter change is conditional and reversible, maintaining high display quality across different operating modes.
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
The solution enhances display quality for moving images by improving step efficiency and reduces power consumption while eliminating text ghost phenomena in static images, thereby improving overall display performance.
Implementation Method 1
The OLED device uses an organic light-emitting diode that emits a light based on recombination of electrons and holes
Data Source
AI summary
A display device includes: a display panel including: a scan line, a data line, and an emission control line; a pixel including: a plurality of transistors connected to the scan line, the data line and the emission control line; and an organic light-emitting diode driven by the plurality of transistors, and a scan driver configured to: in response to an image mode being a moving image mode, generate a first mode scan signal having a turning-on voltage of a transistor for a plurality of horizontal periods; and in response to the image mode being a static image mode, generate a second mode scan signal having the turning-on voltage for a single horizontal period.