Overview
IEC 62906-1-2:2015 - "Laser display devices - Part 1-2: Vocabulary and letter symbols" is an IEC international standard that establishes preferred terms, definitions and letter symbols for laser display devices and related components. Its purpose is to harmonize terminology across publications and countries for consistent technical communication in the field of laser-based displays, projection systems and associated measurement reports.
Key topics
- Standardized vocabulary for laser display devices, including fundamental terms such as laser display device (LDD) and hybrid LDD.
- Speckle terminology and classification:
- Definitions of speckle, monochromatic speckle, colour speckle, objective speckle, subjective speckle, projected speckle, screen speckle, and speckle grain size.
- Introduction to speckle contrast ratio (SCR) (symbol C) and its role in describing speckle visibility.
- Informative Annex A: categorization of objective vs. subjective speckle, and guidance including the minimum objective and subjective speckle grain size relationships (formulas relating wavelength λ and angular aperture θ).
- Display category terminology: raster-scanned projection, full-frame projection, line-scanned projection, front/rear projection, and retina direct projection.
- Optical and source terms: definitions for screens, spatial light modulators (LCOS, DMD), and light-source types (e.g., second harmonic generation laser).
- Letter symbols (quantity/unit symbols): a concise table of symbols used in the series (for example, C for speckle contrast ratio; s_obj, s_subj for minimum speckle grain sizes).
Applications and who uses it
This vocabulary standard is practical for:
- Manufacturers and designers of laser projectors, laser display modules, LCOS/DMD systems, and retinal displays to ensure consistent product specifications and datasheets.
- Test laboratories and QA teams that prepare measurement reports (especially on speckle and image artifacts).
- Standards writers, regulators and procurement teams who need harmonized terminology for regulations, standards references and procurement documents.
- Researchers and academics working on speckle mitigation, laser imaging and human visual perception of laser displays.
Practical uses include documentation consistency, clearer product requirements, unambiguous test methods referencing, and improved international interoperability of technical literature related to laser display devices.
Related standards
- Part of the IEC 62906 series (Laser display devices); consult other parts of IEC 62906 for system requirements, test methods or safety-related content. IEC technical committee: TC 110 (Electronic display devices).