ISO/TR 9241-331:2012

Overview

ISO/TR 9241-331:2012 - "Ergonomics of human‑system interaction - Part 331: Optical characteristics of autostereoscopic displays" provides an ergonomic framework for the optical properties of autostereoscopic displays (ASDs) with the primary aim of reducing visual fatigue from stereoscopic images. The Technical Report defines terminology, specifies performance characteristics, and describes optical measurement methods applicable to spatially interlaced ASDs (two‑view, multi‑view and integral displays) of both transmissive and emissive types - including flat‑panel and projection implementations. The document is informative (a Technical Report) and intended to guide characterization and validation rather than to serve as regulatory requirements.

Key topics

• Terminology and definitions for 3D display concepts: autostereoscopic displays, stereoscopic images/views, monocular views, accommodation, convergence, binocular parallax, and visual fatigue.
• Autostereoscopic technologies: overview and classification of two‑view, multi‑view and integral display designs and depth cues they provide.
• Performance characteristics used to evaluate ASDs, including:
  • 3D crosstalk and interocular crosstalk
  • Interocular luminance, chromaticity and contrast differences
  • Visual artefacts (e.g., 3D moiré, pseudoscopic images)
  • 3D image resolution and 3D fidelity
• Optical measurement methods and recommended measurement conditions to quantify the above characteristics.
• Viewing spaces and analysis: how viewing zones and head‑position affect stereoscopic perception and display evaluation.
• Sections flag areas for future work and updates as technologies evolve.

Applications and practical value

ISO/TR 9241-331 is practical for anyone involved in the design, testing or deployment of glasses‑free 3D systems:

• Display manufacturers - to characterize ASD optical performance and identify sources of visual fatigue.
• Test laboratories and QA teams - to adopt consistent optical measurement methods for comparative evaluation.
• Ergonomists and human‑factors engineers - to assess user comfort and reduce symptoms like eyestrain and headaches.
• System integrators and product designers - to optimize viewing spaces and content presentation for user comfort.
• Researchers and developers - to benchmark new autostereoscopic technologies and guide future improvements.

Related standards

• ISO 9241 series (ergonomics of human‑system interaction), notably:
  • ISO 9241-302:2008 (terminology and display concepts)
  • ISO 9241-303 (performance objectives for head‑mounted displays - related but not directly applicable)
  • Other ISO 9241 parts covering optical, performance and test methods for electronic visual displays (e.g., parts 305–307).
• IWA 3:2005 (image safety and visual fatigue considerations) - referenced in the Technical Report.

This Technical Report is a practical reference for improving 3D display ergonomics, standardizing measurement practices, and minimizing user visual fatigue in autostereoscopic systems.