Polymer Dispersed Liquid Crystal Display with Time-Division Light Emission
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Solution Overview
Problem
Current display devices face challenges in efficiently controlling transmittance and scattering of light to enhance image visibility and background suppression, particularly in field-sequential systems where color filter absorption leads to reduced transmittance and increased complexity.
Innovation Solution
A display device incorporating a liquid crystal layer with polymer dispersed liquid crystals between translucent substrates, where light emitters emit light in time-division manner, and a display controller manages transmittance by applying voltages to control scattering and gradation values, including a non-light-emitting period between light-emitting periods to optimize image visibility and background suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If color filters are used in field-sequential systems to display different colors, then color display capability is improved, but transmittance is reduced and device complexity increases
Solution Approach 1:
The patent extracts and removes the color filter component from the display system. Instead of using color filters to achieve color display, the system uses a single light emitter that sequentially emits different colors (R, G, B) and controls the liquid crystal layer's light scattering properties to create the color display effect, thereby eliminating the transmittance loss caused by color filters
Solution Approach 2:
The patent implements periodic action by making the light emitter emit light in a time-division manner, sequentially displaying different colors (R, G, B) in different time periods. Combined with periodic control of the liquid crystal layer's scattering state, this achieves color display without requiring physical color filters, thus maintaining high transmittance
2Illumination intensity
If light emitters continuously emit light to improve brightness, then illumination intensity is improved, but background suppression capability deteriorates
Solution Approach 1:
The patent uses periodic action by introducing non-light-emitting periods between light-emitting periods. During light-emitting periods, the light emitter emits light and the liquid crystal layer is in a non-scattering state for normal display. During non-light-emitting periods, the light emitter stops emitting and the liquid crystal layer switches to a scattering state to scatter external light, achieving background suppression while maintaining overall brightness through the time-division approach
3Speed
If liquid crystal layer responds quickly to improve responsiveness, then speed is improved, but image clarity deteriorates due to color breakup
Solution Approach 1:
The patent applies periodic action by synchronizing the liquid crystal layer's scattering state transitions with the light emitter's color display periods. The liquid crystal layer switches between non-scattering and scattering states in coordination with the sequential R, G, B emission and non-light-emitting periods, ensuring that fast response does not cause color breakup but instead enhances the field-sequential color display effect
Solution Approach 2:
The patent implements feedback control where the display controller monitors and coordinates the liquid crystal layer's scattering state with the light emitter's operation. By providing feedback control of the scattering state transitions, the system ensures that the liquid crystal layer responds at the appropriate timing for each color period, maintaining image clarity while utilizing fast response capability
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
This solution improves transmittance and image visibility by controlling light scattering and gradation values, reducing color breakup and enhancing image clarity while minimizing background influence, thus overcoming limitations in field-sequential systems.
Implementation Method 1
the light modulation layer transmits the incident light received from the light source when the electric field is not generated, and scatters the incident light and emits the scattered light to the transparent substrates when the electric field is generated
Implementation Method 2
a liquid crystal layer including polymer dispersed liquid crystal sealed between the first translucent substrate and the second translucent substrate
Data Source
AI summary
According to an aspect, a display device includes: a first translucent substrate; a second translucent substrate facing the first translucent substrate; a liquid crystal layer including polymer dispersed liquid crystal sealed between the first translucent substrate and the second translucent substrate; at least one light emitter facing at least one of a side surface of the first translucent substrate or a side surface of the second translucent substrate; and a display controller that controls transmittance of light passing through the first translucent substrate and the second translucent substrate. A non-light-emitting period in which the at least one light emitter does not emit light is provided between a plurality of light-emitting periods in which the at least one light emitter emits light.