Switchable Anti-Peep LCD Stack for Clear Vehicle Displays

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Solution Overview

Problem

Existing anti-peep display screens suffer from poor display quality and limited functionality, primarily due to their reliance on grating structures that restrict viewing angles, leading to a single anti-peep function.

Innovation Solution

Combining a passive LCD module with a color LCD module, utilizing a first and second electrode layer to control the deflection angle of liquid crystal molecules, enabling the anti-peep function to be turned on or off while maintaining image quality, and allowing for independent control of the anti-peep function in multiple areas through customized sub-electrode designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If grating structures with spacing between 0.02 mm and 0.1 mm are used to achieve anti-peep effect, then the anti-peep function is achieved, but the display effect deteriorates

Engineering Contradiction:
Improveanti-peep functionVSAvoiddisplay effect
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The display screen is divided into two separate modules: a color LCD module for displaying content and a passive LCD module for controlling viewing angles. This segmentation allows each module to perform its specialized function optimally - the color LCD provides high-quality color display while the passive LCD with liquid crystal molecules controls the light transmission angle, resolving the contradiction between anti-peep function and display quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The passive LCD module acts as an intermediary between the viewer and the color LCD module. It contains liquid crystal molecules that can be controlled to change their orientation, thereby mediating the light transmission angle. When voltage is applied, the liquid crystal molecules realign to block oblique viewing angles while maintaining front-facing visibility, achieving anti-peep effect without degrading the underlying color display quality

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If grating structures are used for anti-peep effect, then viewing angle is restricted, but the display function becomes single-purpose

Engineering Contradiction:
Improveviewing angle restrictionVSAvoiddisplay function
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The passive LCD module introduces dynamic control capability through voltage-driven liquid crystal molecules. The anti-peep function is not fixed but can be dynamically adjusted - when voltage is applied, the liquid crystal molecules realign to restrict viewing angles; when voltage is removed, they return to their original state allowing normal viewing. This dynamic switching capability transforms the display from single-purpose to multi-functional, enabling both normal display and anti-peep modes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stacked module design creates a universal display system that can perform multiple functions. The color LCD module provides color display functionality, while the passive LCD module adds anti-peep functionality. Together, they create a display system that can operate in normal mode (for general viewing) and anti-peep mode (for privacy protection), making the display adaptable to different usage scenarios and requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If passive LCD module with liquid crystal control is used, then anti-peep function is enhanced, but device complexity increases

Engineering Contradiction:
Improveanti-peep controlVSAvoidmodule structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The liquid crystal molecules in the passive LCD module are self-controlled through electrical fields. When voltage is applied between the electrode layers, the liquid crystal molecules automatically realign themselves perpendicular to the substrate to block oblique light. This self-service mechanism eliminates the need for complex mechanical structures or additional control systems, achieving anti-peep control through simple electrical actuation of the liquid crystal material's inherent properties

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The passive LCD module is nested in front of the color LCD module, with the two modules stacked together to form an integrated display system. The passive LCD module contains electrode layers and liquid crystal molecules nested between glass substrates, creating a compact structure. This nesting approach allows the anti-peep functionality to be integrated into the existing display system without requiring separate external components, thereby limiting the increase in device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Enhances image display quality while effectively protecting content from peeping by ensuring clarity only when viewed directly, with the ability to customize anti-peep functionality for various scenarios.

Implementation Method 1

The first sub-electrode and the second sub-electrode are opposite to each other and configured to input different voltages, so as to control a light transmission state of the passive LCD module

Methodology Applied
Scientific EffectLiquid crystal deflection: Liquid Crystals

Implementation Method 2

The passive LCD module is a twisted nematic display module, where a pretilt angle of liquid crystal molecules in the twisted nematic display module is 1°-7°, a twist angle thereof is 80°-100°

Methodology Applied
Scientific EffectTwisted nematic effect: Liquid Crystals

Implementation Method 3

control a light transmission state of the passive LCD module

Methodology Applied
Scientific EffectLight transmission control: Liquid Crystals

Implementation Method 4

a retardation is 500 nm-1200 nm

Methodology Applied
Scientific EffectOptical anisotropy: Birefringence

Data Source

PatentEP4509907B1Anti-peep display screen, vehicle-mounted display device and vehicle
Publication Date: 2026.02.11 VARITRONIX HEYUAN DISPLAY TECH
  • EP4509907B1 patent drawingFigure 1~4
  • EP4509907B1 patent drawingFigure 5~8
  • EP4509907B1 patent drawingFigure 9~12

AI summary

Provided is an anti-peep screen, including a passive LCD module (1) and a color liquid crystal display module (2) stacked along a first direction (X); the passive LCD module (1) includes a first electrode layer (11), a liquid crystal layer (12) and a second electrode layer (13), the first electrode layer (11) comprises a first sub-electrode (111), the second electrode layer (13) comprises a second sub-electrode (131), and the first sub-electrode (111) is opposite to the second sub-electrode (131) and configured to input different voltages, so as to control a light transmission state of the passive LCD module (1). The anti-peep display screen of the present application solves the problems of poor display effect and single anti-peep function of existing anti-peep display screens by introducing a passive LCD module (1). Also provided is a vehicle-mounted display device and a vehicle.