Display System with Active Diffuser for Privacy Control
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Solution Overview
Problem
Console-based displays in automobiles often face conflicts between drivers and passengers over content visibility, as existing technologies do not effectively manage privacy and public viewing modes, leading to inadequate control over light scattering and brightness.
Innovation Solution
A display system with a collimated backlight source, passive and active diffusers, and a transmissive display that can switch between public and private viewing modes by controlling light scattering, allowing for independent zone control of brightness and scattering states, enabling a high dynamic range and contrast ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional backlight display is used, then the display is visible to all passengers, but privacy control is lost and content is visible to unauthorized users
Solution Approach 1:
The patent implements dynamic control of light scattering properties through an active diffuser that can switch between scattering and non-scattering states. This allows the display to adapt between public viewing mode (scattering state for broad visibility) and private viewing mode (non-scattering state for restricted visibility), resolving the contradiction between privacy control and viewing mode versatility.
Solution Approach 2:
The patent divides the backlight into multiple independently controllable zones with local dimming capability. Each zone can be individually adjusted for brightness and scattering properties, allowing different parts of the display to serve different functions (e.g., driver information in private mode, entertainment in public mode), thus achieving both privacy control and adaptability.
2Illumination intensity
If local dimming is implemented, then brightness control is improved, but device complexity increases
Solution Approach 1:
The patent segments the backlight into multiple independently controllable zones, allowing local dimming where different regions can have different brightness levels. This segmentation enables precise brightness control for different viewing scenarios while managing complexity through modular zone control.
Solution Approach 2:
The active diffuser serves multiple functions: it acts as a privacy control mechanism, a light scattering element, and a viewing mode selector. By combining these functions into a single component that can switch between scattering and non-scattering states, the patent reduces overall system complexity despite implementing local dimming.
3Object-affected harmful factors
If an active diffuser is added for privacy mode, then privacy control is achieved, but device complexity and cost increase
Solution Approach 1:
The active diffuser is designed to perform multiple functions: privacy control, light scattering, and viewing mode selection. By making this single component multi-functional, the patent achieves privacy control without proportionally increasing device complexity, as the same component handles multiple tasks that would otherwise require separate elements.
Solution Approach 2:
The active diffuser changes its optical parameters (scattering vs. non-scattering state) in response to control signals, allowing privacy control through parameter modulation rather than mechanical movement or additional components. This parametric control achieves privacy functionality while minimizing structural complexity.
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 provides a high contrast ratio of up to 15,000:1 and allows for user-selectable brightness levels, ensuring optimal image quality in both private and public viewing modes by controlling light scattering and brightness across zones.
Implementation Method 1
The plurality of lenses may be mounted adjacent to the backlight source, aligned with the plurality of light sources and are configured to generate a collimated light by redirecting the initial light
Implementation Method 2
The passive diffuser may be mounted adjacent to the lenses and is configured to spatially spread the collimated light
Implementation Method 3
The active diffuser may be mounted adjacent to the passive diffuser, is configured to generate an intermediate light in response to the collimated light and is configured to change a diffusive property of the intermediate light between a scattering state in a public viewing mode and a non-scattering state in a private viewing mode
Data Source
AI summary
A display with local dimming backlight and an active privacy mode. The display may include a backlight source, lenses, a passive diffuser, an active diffuser and a transmissive display. The backlight source may define a two-dimensional matrix of light sources configured to generate an initial light. The lenses may be mounted adjacent to the backlight source, aligned with the light sources, and configured to generate a collimated light. The passive diffuser may be mounted adjacent to the lenses and configured to spatially spread the collimated light. The active diffuser may be mounted adjacent to the passive diffuser, configured to generate an intermediate light in response to the collimated light, and configured to change a diffusive property of the intermediate light in response to a scattering signal. The transmissive display may be mounted adjacent to the active diffuser and configured to generate multiple visible images by modulating the intermediate light.