Overview
IEC 62715-5-3:2017 - Flexible display devices - Part 5-3: Visual assessment of image quality and defects - defines a standardized framework and procedures for the visual assessment of flexible display devices. The standard covers assessments in multiple states: initial and ageing under standard ambient conditions, during or after mechanical and environmental stress, and after combined endurance tests. Visual inspection is performed by comparing a Device Under Test (DUT) to a limit sample or a set of grade samples, and the document also provides guidance when such comparison samples are not available. The standard includes recommended test patterns to support consistent visual evaluations.
Key topics and technical requirements
- Scope of assessment: Applicable to flexible display modules in initial, aged, stressed, and post-endurance-test conditions.
- Assessment methods: Comparative judgment using a limit sample or a set of grade samples; procedures for cases without comparison samples.
- Test setup and driving conditions: Requirements for how displays are driven and prepared for visual evaluation.
- Observers and procedures: Guidance on selecting and managing observers for repeatable visual results.
- Ambient and lighting conditions: Standard environmental conditions and lighting setups for consistent visual inspection.
- Viewing geometry: Defined viewing geometries (designed, standard usage, and rigorous) to replicate real-world and laboratory viewing angles.
- Test charts / test patterns: Full-screen, periodic, tone and colour gradation, cross-talk, electro-optical defect charts, static image resolution, and natural/synthetic images. (Includes example input signal levels for 8-bit systems.)
- Assessment after stress tests: Specific procedures for visual inspection during and after mechanical and environmental stresses.
- Judgement criteria: Procedures for ranking or judging defects, including use of Neutral Density (ND) filters and methods for mechanical defects.
- Reporting: Required and recommended reporting elements to ensure traceable, consistent results.
Applications and who should use it
IEC 62715-5-3 is intended for:
- Display manufacturers and module integrators for quality control and production acceptance
- R&D teams developing flexible, foldable or wearable displays to validate image quality
- Test laboratories and certification bodies performing visual image-quality assessments
- Failure analysis and QA engineers assessing defects such as mura, color non-uniformity, cross-talk and mechanical deformation
Use cases include end-of-line inspection, acceptance testing after environmental/mechanical endurance, supplier qualification, and creation of contract or product specifications.
Related standards
- IEC 62715 series (other parts covering flexible display device requirements)
- IEC 62341-6-2 and IEC 61747-20-3 (referenced guidance on visual assessment procedures for electronic displays)
Keywords: IEC 62715-5-3, flexible display devices, visual assessment, image quality, display defects, limit sample, grade samples, test patterns, viewing geometry, ambient lighting.