Ghost Illumination Cancellation in Display Panels via Parasitic Capacitance Management
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Solution Overview
Problem
Display panels suffer from 'ghosting' due to the charging and discharging of parasitic capacitances, leading to unwanted illumination and energy wastage, which affects display quality and battery life in battery-powered devices.
Innovation Solution
A display system with a matrix of display elements arranged in rows and columns, where each row and column has a dedicated driver, and a switch driver configures switches to charge and discharge parasitic capacitances through a storage capacitor, eliminating ghosting by redirecting charge flows and pre-charging capacitances to minimize energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If parasitic capacitances are charged and discharged during display operation, then display elements can be updated, but ghost illumination occurs causing display quality degradation
Solution Approach 1:
The patent extracts the harmful charge discharge path by introducing a dedicated discharge capacitor that is selectively connected to the parasitic capacitance. This separates the discharge function from the normal display operation path, allowing ghost illumination to be eliminated without affecting the primary display function.
Solution Approach 2:
The discharge capacitor acts as an intermediary element between the parasitic capacitance and ground. It provides a controlled discharge path that prevents direct charge leakage causing ghosting, while the switching mechanism controls when this intermediary is connected to manage the discharge process.
2Loss of energy
If parasitic capacitances are discharged through traditional paths, then charge is removed, but energy is wasted reducing battery life
Solution Approach 1:
The patent recovers energy that would otherwise be wasted by capturing the discharge current from parasitic capacitances through the dedicated discharge capacitor. This recovered energy is dissipated in a controlled manner or can be redirected, reducing the overall energy loss and extending battery operation.
Solution Approach 2:
The discharge capacitor and switching mechanism create a self-managing system where parasitic capacitances are automatically discharged through the optimized path without requiring external intervention. The system serves itself by managing its own parasitic effects and energy recovery.
3Object-generated harmful factors
If switches are added to control charge discharge paths, then ghosting is eliminated, but device complexity increases
Solution Approach 1:
The patent segments the charge discharge control by introducing separate switching mechanisms for different paths. Instead of a single complex switch controlling all operations, the system divides control into distinct segments: one for normal display operation and another for parasitic capacitance discharge, simplifying the overall control architecture.
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 effectively eliminates ghosting in display panels, enhancing display quality and reducing energy wastage by managing parasitic capacitance charges efficiently, thereby prolonging battery life in portable devices.
Implementation Method 1
A display system with a matrix of display elements arranged in rows and columns, where each row and column has a dedicated driver, and a switch driver configures switches to charge and discharge parasitic capacitances through a storage capacitor
Data Source
AI summary
Display elements, each having anode and cathode terminals, are arranged into rows and columns. Each row has an anode-line coupled to the anode terminals for its display elements. Each column has a cathode-line coupled to the cathode terminals for its display elements. A switch for each anode-line selectively couples that anode-line to a storage capacitor, and a switch for each cathode-line selectively couples that cathode-line to the storage capacitor. A display driver activates the row driver for a given row and the column driver for a given column. A switch driver closes the switch for the cathode-line for the given column, then opens the switch for that cathode-line. The display driver deactivates the row driver for the given row, after closing the switch for the cathode-line for the given column. The switch driver closes the switch for the anode-line for the given row.