LC Grating Placement for 3D Touch Display Without Signal Shielding
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Solution Overview
Problem
For medium and small size display products using the in-cell touch technology, the liquid crystal grating overlaid on the light emitting side of the display panel causes a shielding effect on the touch electrode, leading to touch failure and reduced display brightness.
Innovation Solution
A liquid crystal grating panel is positioned between the backlight module and the liquid crystal touch display panel, with separate transparent electrode layers receiving alternating and direct current drive signals, and a master controller manages distinct drive frequencies to avoid interference, allowing for touch recognition and 3D display without compromising touch sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the liquid crystal grating is directly overlaid on the light emitting side of the display panel, then glass-free 3D display is achieved, but the touch electrode cannot sense human finger charges causing touch failure and reduced display brightness
Solution Approach 1:
The patent introduces a temporal dimension by using different drive frequencies for the liquid crystal grating panel and the liquid crystal touch display panel. The grating panel operates at a first drive frequency while the touch panel operates at a second drive frequency, allowing them to function simultaneously without interference. This frequency division enables both 3D display and touch sensitivity to coexist by separating their operational domains in the time-frequency domain.
2Adaptability or versatility
If the liquid crystal grating is directly overlaid on the light emitting side of the display panel, then glass-free 3D display is achieved, but the display brightness is greatly reduced
Solution Approach 1:
The patent introduces a temporal dimension by using different drive frequencies for the liquid crystal grating panel and the liquid crystal touch display panel. The grating panel operates at a first drive frequency while the touch panel operates at a second drive frequency, allowing them to function simultaneously without interference. This frequency division enables both 3D display and touch sensitivity to coexist by separating their operational domains in the time-frequency domain.
Solution Approach 2:
The patent employs periodic switching at different frequencies for the grating panel and touch panel. By using alternating current drive signals with different frequencies, the system creates periodic light transmittance patterns that enable 3D display while allowing touch electrodes to periodically sense finger charges without continuous shielding interference.
3Reliability
If separate transparent electrode layers receiving alternating and direct current drive signals are used, then touch sensitivity is enhanced, but device complexity increases
Solution Approach 1:
The patent makes the liquid crystal grating panel serve multiple functions: it acts as both the 3D display grating element and a separate driveable component with its own transparent electrode layers. The first transparent electrode layer and second transparent electrode layer in the grating panel can be independently controlled, allowing the same structural element to fulfill both 3D display and touch recognition functions without requiring entirely separate systems.
Solution Approach 2:
The patent divides the drive signals into separate frequency domains - the grating panel receives drive signals at a first drive frequency while the touch panel receives signals at a second drive frequency. This segmentation of operational frequencies allows the transparent electrode layers to be controlled independently, reducing interference between the grating function and touch sensing function.
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 prevents touch electrode shielding, enhances touch sensitivity and accuracy, and improves light utilization, enabling effective glass-free 3D display with dynamic adjustment of light transmittance regions.
Implementation Method 1
a liquid crystal grating panel, arranged between the backlight module and the liquid crystal touch display panel
Implementation Method 2
the first transparent electrode layer is configured to receive an alternating current drive signal; a first liquid crystal layer, arranged between the first array substrate and the liquid crystal touch display panel
Implementation Method 3
a first polarizer, arranged between the liquid crystal grating panel and the backlight module; a second polarizer, arranged between the liquid crystal grating panel and the liquid crystal touch display panel
Implementation Method 4
an electrode in the liquid crystal grating will generate a shielding effect on a touch electrode in the touch module, so that the touch electrode cannot sense human finger charges
Data Source
AI summary
The present disclosure relates to a display apparatus and a drive method thereof. The display apparatus includes a backlight module; a liquid crystal touch display panel, located on a light emitting side of the backlight module; and a liquid crystal grating panel, located between the backlight module and the liquid crystal touch display panel.