HMD Transmittance Control via Liquid Crystal Shutter

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Solution Overview

Problem

Users of optically transmissive Head-Mounted Displays (HMDs) experience annoyance when external light is suddenly shut off while viewing the outside world in a see-through mode, affecting usability.

Innovation Solution

A stereoscopic video observation device with a transmittance control system that adjusts the amount of external light using a liquid crystal shutter, setting a lower limit value of transmittance based on illuminance, motion, and proximity to ensure visibility and usability, while providing notifications for transmittance changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the transmittance of external light is adjusted using optical shutters to improve video visibility, then the visibility of video on the HMD is improved, but the user suddenly becomes unable to view the outside world when external light is unexpectedly shut off, causing annoyance

Engineering Contradiction:
Improvevideo visibilityVSAvoidusability
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The system performs preliminary actions by detecting conditions (illuminance, motion, proximity) before making transmittance adjustments, and by providing advance notifications to users before shutting off external light, thus preventing sudden unexpected changes that cause annoyance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from sensors (illuminance detection, motion detection, proximity detection) to continuously monitor the environment and adjust transmittance accordingly, ensuring that adjustments are made based on actual conditions rather than arbitrarily

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the transmittance is adjusted based on illuminance, motion, and proximity detection, then the visibility and usability are improved, but the device complexity increases due to multiple sensors and control mechanisms

Engineering Contradiction:
ImproveusabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The optical shutters serve multiple functions: they control light transmittance for video visibility, respond to motion detection for safety, react to proximity detection for comfort, and provide notifications to users, making a single component perform multiple roles

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

Solution Approach 2:

The patent combines multiple detection functions (illuminance detection, motion detection, proximity detection) into a unified control system that manages optical shutter transmittance, integrating separate sensing capabilities into a coordinated control mechanism

Inventive Principle:
Principle #5Merging (Combining)

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

Improves the usability of optically transmissive HMDs by maintaining visibility of the outside world during use while allowing for adjustments in light transmittance to enhance user experience and reduce annoyance from unexpected changes.

Implementation Method 1

a transmittance changing section that changes the transmittance of external light passing through the optically transmissive HMD

Methodology Applied
Scientific EffectLiquid crystal: Liquid Crystals

Data Source

PatentEP2869115B13D video observation device and transmittance control method
Publication Date: 2022.06.01 SONY INTERACTIVE ENTERTAINMENT LLC
  • EP2869115B1 patent drawingFigure 1
  • EP2869115B1 patent drawingFigure 2
  • EP2869115B1 patent drawingFigure 3

AI summary

In a stereoscopic video observation device 200, an optically transmissive HMD 208 presents video observed when a three-dimensional image in a virtual three-dimensional space is projected into a real space. A transmittance changing section changes the transmittance of light that passes through the optically transmissive HMD 208. A shutter control section 220 sets a lower limit value of the light transmittance that can be changed by the transmittance changing section.