Dual Backlight Module for Privacy Display Brightness Control

Solution Overview

Problem

Current privacy display devices have issues with brightness at wide viewing angles, causing annoyance to people nearby, and lack effective switching between wide and narrow modes.

Innovation Solution

The electronic device incorporates a non-collimated backlight module and a transparent backlight module, with the non-collimated module being off in narrow mode and the transparent module being on, to achieve privacy by limiting the viewing angle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a privacy display device uses a single backlight module, then the device structure is simple, but the brightness at wide viewing angles is not low enough causing annoyance to nearby people

Engineering Contradiction:

Improvebacklight module structureVSAvoidbrightness at wide viewing angle

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The backlight system is divided into two separate modules: a first backlight module for wide viewing angle illumination and a second backlight module for narrow viewing angle privacy mode. This segmentation allows independent control of each module's brightness and viewing characteristics, resolving the contradiction between simple structure and controlled brightness at wide angles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different backlight modules based on the desired viewing mode. A control mechanism enables transition between wide mode (using first backlight module) and narrow mode (using second backlight module), allowing the display to adapt its brightness characteristics to different usage scenarios and eliminate unwanted wide-angle visibility.

Inventive Principle:

Principle #15Dynamics

2Illumination intensity

If a privacy display device uses multiple backlight modules, then the brightness at wide viewing angles can be controlled, but the device structure becomes complex

Engineering Contradiction:

Improvebrightness at wide viewing angleVSAvoidbacklight module structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The backlight system is divided into two separate modules: a first backlight module for wide viewing angle illumination and a second backlight module for narrow viewing angle privacy mode. This segmentation allows independent control of each module's brightness and viewing characteristics, resolving the contradiction between simple structure and controlled brightness at wide angles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each backlight module is designed to serve multiple functions: the first module provides both wide-angle illumination and can be controlled for privacy mode, while the second module provides narrow-angle privacy viewing and can contribute to overall illumination. This multi-functionality reduces the need for additional specialized components, managing structural complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If current privacy display devices are used, then privacy function is provided, but switching between wide mode and narrow mode is not effective

Engineering Contradiction:

Improveprivacy functionVSAvoidswitching between modes

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between different backlight modules based on the desired viewing mode. A control mechanism enables transition between wide mode (using first backlight module) and narrow mode (using second backlight module), allowing the display to adapt its brightness characteristics to different usage scenarios and eliminate unwanted wide-angle visibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The switching between wide mode and narrow mode is implemented as a controllable periodic or on-demand action, where the system can alternate between modes based on user needs. This periodic switching capability ensures reliable privacy protection when needed while maintaining adaptability for different viewing requirements.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS12287539B2Electronic device

Publication Date: 2025.04.29 INNOLUX CORP

AI summary

An electronic device includes: a non-collimated backlight module; a transparent backlight module disposed on the non-collimated backlight module, wherein the transparent backlight module includes a direct-lit backlight module or an edge-lit backlight module; and a display cell disposed on the transparent backlight module; wherein when in a narrow mode, the non-collimated backlight module is in an off-state, and the transparent backlight module is in an on-state, wherein when in a wide mode, the non-collimated backlight module is in an on-state.