Liquid Crystal Shutter Driving Method for Flicker Suppression
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Solution Overview
Problem
Liquid crystal shutters used for three-dimensional image display often experience flicker due to slight direct-current voltages applied to the panels, which affects the transmissivity and chromaticity of the images, leading to a suboptimal viewing experience.
Innovation Solution
A liquid crystal shutter system with a driving method that includes a first and second liquid crystal panel, each with electrode substrates and a liquid crystal layer, switched between transmissive and non-transmissive states using a driving circuit that inverts the polarity of the applied voltage at least once during a transmissive period, allowing for synchronized image display for left and right eyes without flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct-current voltage is applied to the liquid crystal panel for shutter operation, then the liquid crystal panel can be switched between transmissive and non-transmissive states, but flicker occurs due to slight direct-current components
Solution Approach 1:
The patent applies periodic alternating voltage to the liquid crystal panel instead of direct-current voltage. The voltage polarity is inverted at regular intervals (e.g., every frame period or half-frame period), creating a periodic action that prevents the accumulation of slight direct-current components. This periodic inversion eliminates the flicker caused by DC bias while maintaining reliable shutter operation between transmissive and non-transmissive states.
Solution Approach 2:
The patent changes the voltage parameter from direct-current to alternating-current with periodic polarity inversion. By modifying the voltage waveform characteristics (from DC to AC with alternating polarity), the system eliminates the harmful flicker effect while preserving the shutter's ability to switch states reliably. The voltage amplitude and inversion timing are optimized to maintain proper liquid crystal alignment without DC bias.
2Productivity
If the liquid crystal shutter switches panels rapidly for three-dimensional display, then left and right eye images can be displayed by turns, but chromaticity adjustment becomes complex requiring voltage optimization
Solution Approach 1:
The patent employs periodic polarity inversion synchronized with the frame timing of the three-dimensional display system. By inverting voltage polarity at regular intervals aligned with the left-right eye image switching, the system maintains chromaticity stability without requiring complex per-frame voltage optimization. The periodic action simplifies chromaticity control while enabling rapid panel switching for 3D display.
3Speed
If the liquid crystal panel responds quickly to voltage changes for high frame frequency display, then three-dimensional image quality improves, but flicker becomes more noticeable with direct-current voltage
Solution Approach 1:
The patent uses periodic polarity inversion that is synchronized with the high frame frequency operation. The rapid inversion of voltage polarity prevents the accumulation of DC components that would cause flicker, while the fast response of the liquid crystal panel to these periodic voltage changes maintains high image quality. The periodic action frequency is matched to the display refresh rate, eliminating flicker even at high speeds.
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 system effectively suppresses flicker and maintains high-speed response, enabling clear three-dimensional image display equivalent to higher frame frequencies, even at lower display frequencies, by optimizing the voltage polarity inversion during both transmissive and non-transmissive states.
Implementation Method 1
a liquid crystal layer held between the electrode substrates... switched between a transmissive state and a non-transmissive state by applying a voltage
Implementation Method 2
carrying out a polarity inversion driving to invert the polarity of the voltage applied between the pair of the electrode substrates at least once during a period in the transmissive state
Data Source
AI summary
In one embodiment, a liquid crystal shutter includes a first liquid crystal panel for left eye and a second liquid crystal panel for right eye. Each liquid crystal panel includes a pair of electrode substrates and a liquid crystal layer held between the electrode substrates. A driving circuit switches the first and second liquid crystal panels between a transmissive state and a non-transmissive state by turns by applying a voltage to the first and second liquid crystal panels while inversing the polarity of the voltage applied between the pair of the electrode substrates at least once during a period in the transmissive state.