Electrophoretic Display Driver Voltage Control Sequence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophoretic display technologies require complex display drivers to achieve multi-level voltage driving, which complicates the control of pixel electrodes and affects the accuracy of light output.
Innovation Solution
A display apparatus and method that utilize a select driver, data driver, and common driver to control select voltages, data voltages, and backplane voltages in a specific sequence to drive pixels with multi-level voltages, allowing for bistable operation and accurate optical state changes without the need for complex drivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multi-level voltage driving is implemented to accurately control particle movement and achieve desired light output, then manufacturing precision and measurement precision are improved, but device complexity increases due to the need for complex display drivers
Solution Approach 1:
The voltage control is segmented into two independent parts: a common voltage applied to the common electrode and a data voltage applied to the pixel electrode. This segmentation allows multi-level voltage control to be achieved through the combination of these two simpler voltage signals, avoiding the need for a complex multi-level driver while maintaining accurate control over particle movement and light output.
Solution Approach 2:
Instead of applying complex multi-level voltages directly to the pixel electrode through a complex driver, the invention inverts the approach by applying a common voltage to the common electrode and a simpler data voltage to the pixel electrode. The desired multi-level effect is achieved through the voltage difference between these two electrodes, simplifying the driver requirements while maintaining control precision.
2Manufacturing precision
If complex display drivers are used to enable multi-level voltage control, then manufacturing precision is improved, but ease of operation deteriorates due to the complexity of controlling pixel electrodes
Solution Approach 1:
The control operation is segmented into two independent and simpler tasks: controlling the common voltage on the common electrode and controlling the data voltage on the pixel electrode. This segmentation makes the system easier to operate because each voltage can be controlled independently using simpler driver circuits, while still achieving the desired multi-level voltage effect for accurate light output control.
Solution Approach 2:
The control approach is inverted by applying voltage to the common electrode rather than directly controlling complex multi-level voltages at the pixel electrode. This inversion simplifies the operation because the common electrode can be controlled with a single voltage signal, and the data electrode requires only simple voltage levels, making the overall system easier to operate while maintaining manufacturing precision.
3Device complexity
If simple voltage driving is used to reduce driver complexity, then device complexity is reduced, but manufacturing precision deteriorates because accurate control of particle movement becomes difficult
Solution Approach 1:
The voltage control is segmented into a common voltage component and a data voltage component, where the common voltage provides the base level for particle movement and the data voltage provides the differential control for precise positioning. This segmentation allows simple driver circuits to generate each voltage component separately, while their combination achieves the multi-level voltage control needed for accurate light output and particle movement control.
Solution Approach 2:
The control strategy is inverted by applying the majority of the voltage control through the common electrode rather than through complex pixel electrode drivers. This inversion allows simple pixel electrode drivers to work in conjunction with a common voltage source to achieve accurate multi-level control, thereby maintaining manufacturing precision while reducing device complexity.
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
Enables the accurate control of pixel voltages to achieve desired light outputs with reduced complexity in the driver systems, improving the reproducibility of grey levels and colors in electrophoretic displays.
Implementation Method 1
the pixels comprise electrophoretic material with charged particles
Data Source
AI summary
A display apparatus comprises pixels (18) associated with intersections of select electrodes (17) and data electrodes (11) and having a bistable operation. A select driver (16) supplies select voltages (VG) to the select electrodes (17) to select a group of pixels (18). A data driver (10) supplies data voltages (VD) to the data electrodes (11) to supply the data voltages (VD) to the group of pixels (18) being selected. A common driver (25) supplies a backplane voltage (VB) to a common electrode (6) common for the group of pixels (18). A controller (15) controls the select driver (16), the data driver (10) and the common driver (25), in the order mentioned: (a) to change the select voltage (VG) to its on-level (on) at which the group of pixels (18) are selected, after the backplane voltage (VB) and the data voltage (VD) for the group of pixels (18) have a same first non-zero level (+15V), or before the backplane voltage (VB) and the data voltage (VD) for the group of pixels (18) are simultaneously changed to the same first non-zero level (+15V), (b) to change the data voltages (VD) in accordance with display data (13) defining an optical state of the individual pixels (18) of the group of pixels (18), (c) to change the select voltage (VG) to its off-level (off) at which the group of pixels (18) are not selected, (d) to change the select voltage (VG) to its on-level (on), after the backplane voltage (VB) and the data voltage (VD) for the group of pixels (18) have a same second non-zero level (−15V), or before the backplane voltage (VB) and the data voltage (VD) for the group of pixels (18) are simultaneously changed to the same second non-zero level (−15V), and (e) to change the data voltages (VD) in accordance with the display data (13).