VCOM Signal Generation Circuit for Display Privacy Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices lack effective privacy protection mechanisms to prevent others from viewing the screen content, which is a concern for users of electronic products such as notebook computers and smartphones.
Innovation Solution
A display device incorporating multiple pixel unit sets and VCOM signal generation circuits, where the VCOM signal generation circuits are divided into groups to generate specific VCOM signals based on clock signals and control signals, allowing for the provision of privacy protection by switching between narrow and wide viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a display device provides a wide viewing angle for better visibility, then the viewing comfort is improved, but privacy protection capability deteriorates
Solution Approach 1:
The patent implements dynamic switching between different VCOM signal modes (normal mode and privacy mode) based on control signals. The display device can dynamically adjust its viewing angle characteristics by switching the VCOM signal generation circuit between different operating states, allowing it to transition from a wide viewing angle state (normal mode) to a narrow viewing angle state (privacy mode) where the display appears black from side angles.
2Reliability
If the VCOM signal generation circuit is implemented with high precision for stable signal output, then the signal stability is improved, but the circuit complexity increases
Solution Approach 1:
The patent divides the VCOM signal generation circuit into multiple independent transistor units (first through twentieth transistors) organized in parallel structures. Each transistor unit can be controlled independently by control signals (P1, P2, P3, P4) to generate different VCOM signal levels. This segmentation allows the circuit to achieve complex signal generation functionality while maintaining modularity and manageable complexity.
Solution Approach 2:
The patent changes the voltage parameters of the VCOM signal by controlling different transistor switches. By adjusting which transistors are activated (through control signals P1-P4), the circuit can output different voltage levels for the VCOM signal, enabling dynamic adjustment of the common electrode voltage to achieve different display modes (normal and privacy modes) with stable signal output.
Data Source
AI summary
A display device comprises a plurality of pixel unit sets and a plurality of common electrode (VCOM) signal generation circuits. Each of the pixel unit sets comprises a first portion pixel unit and a second portion pixel unit. Each of the first portion pixel unit and each of the second portion pixel unit comprise a plurality rows of pixel units. Each row of the pixel units comprises a plurality of pixel units. The VCOM signal generation circuits are respectively coupled to one of the pixel unit sets. The VCOM signal generation circuits are divided into a plurality of groups of number m. The VCOM signal generation circuits in each of the groups generate a first VCOM signal and a second VCOM signal to the coupled pixel unit set according to a first clock signal, a second clock signal and one of a plurality control signal sets of number m.