OLED Display Device Using Reference Voltage for MPRT Improvement
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Solution Overview
Problem
Conventional OLED display devices require time division for black and image frames, leading to increased manufacturing costs and potential picture quality deterioration due to insufficient charging time for subpixels, which affects the accuracy of charging voltage and overall image quality.
Innovation Solution
An OLED display device that utilizes a scan gate driver and sense gate driver to control subpixel charging and light emission, employing a reference voltage lower than the threshold voltage to turn off OLED elements independently of charging time and input data, thereby allowing for improved motion picture response time (MPRT) and picture quality without additional memory for black data storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a black frame is added to each frame by charging black data in each subpixel during every frame to improve motion picture response time, then motion picture response time is improved, but manufacturing costs increase due to the need for additional memory
Solution Approach 1:
The patent extracts the black frame function from the traditional time-division approach and implements it through a dedicated reference voltage line that supplies a voltage lower than the OLED threshold voltage. This eliminates the need for additional memory to store black data, as the reference voltage line directly controls OLED shutdown without requiring separate black frame data storage.
Solution Approach 2:
The reference voltage line serves multiple functions: it provides the threshold voltage for OLED shutdown during black frames, maintains stable operation during image frames, and enables rapid OLED response. This multi-functional approach eliminates the need for separate dedicated black frame control circuits and additional memory components.
2Speed
If each frame is time-divided into a black frame and an image frame, then motion picture response time is improved, but picture quality deteriorates due to insufficient charging time for subpixels
Solution Approach 1:
The patent implements dynamic control of the reference voltage line that can be selectively activated during black frames while being inactive during image frames. This dynamic approach allows the system to optimize for both rapid response (during black frames) and adequate charging time (during image frames), as the reference voltage is only applied when needed for OLED shutdown.
Solution Approach 2:
The reference voltage is applied periodically during black frames rather than continuously. This periodic application allows OLED elements to be turned off during black frames for rapid response while maintaining normal charging operations during image frames, thus preserving picture quality while achieving improved motion response.
3Speed
If a reference voltage lower than threshold voltage is supplied to the OLED element to turn it off, then motion picture response time is improved, but the OLED element may not turn off completely if the reference voltage is not sufficiently low
Solution Approach 1:
The patent carefully selects and maintains the reference voltage at a specific parameter level that is lower than the OLED threshold voltage. This parameter control ensures that when the reference voltage is applied during black frames, it reliably turns off the OLED element by pushing the gate voltage below the threshold required for conduction, guaranteeing complete shutdown and rapid response.
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 enables improved MPRT and picture quality by ensuring sufficient charging time for subpixels and eliminating the need for additional memory, reducing manufacturing costs and preventing picture quality deterioration.
Implementation Method 1
an organic light-emitting diode (OLED) display device using OLEDs, and an electrophoretic display (EPD) using electrophoretic particles... the OLED display device is a self-luminescent device which causes an organic light-emitting layer to emit light through recombination of electrons and holes
Data Source
AI summary
An OLED display device capable of improving picture quality by turning off an OLED element regardless of a charging time and input data of each subpixel is discussed. A reference voltage supplied to a reference line is supplied to an OLED element during at least one OLED off time after a light-emitting time and before a charging time according to control of a scan gate line and a sense gate line to turn off the OLED element. The reference voltage is lower than a threshold voltage of the OLED element.