Overview
IEC 62906-5-5:2022 - "Laser displays – Part 5-5: Optical measuring methods of raster-scanning retina direct projection laser displays" defines standard measurement conditions and optical test methods for raster‑scanning retina direct projection (RS‑RDP) laser displays using direct‑emitting lasers (and optionally higher‑order harmonic generation devices). Hybrid sources that mix lasers with spontaneous‑emission light sources are excluded. The standard establishes how to measure optical power, retinal illuminance and image quality parameters in a repeatable, safety‑aware way.
Key topics and technical requirements
- Standard measuring conditions: environmental conditions, coordinate system, and setup requirements for reproducible measurements.
- Measurement points: defined optical power measurements at the exit window (measurement point 1) and at the focal point (measurement point 2), with methods to eliminate spectral cross‑effects.
- Required instruments: guidance for suitable light‑measuring devices including planar 2D image sensors and goniometric spectroradiometers.
- Image and view parameters:
- Eye‑box and its measurement geometries
- Field of view (FOV) and aspect ratio
- Effective angular image resolution with test patterns and contrast/MTF‑style evaluation
- Retinal free focus range (direct and imaging methods)
- Retinal white illuminance, luminance and chromaticity of the virtual image
- White and chromaticity nonuniformity
- Safety: laser‑safety requirements for measurement setups are included to protect operators and test equipment.
- Reporting: standardized reporting items and measurement locations to ensure consistent documentation.
Practical applications and who uses it
- Display manufacturers: validate performance, characterize beamforming and image quality of retina‑directed laser products.
- Test laboratories and QA teams: perform conformity testing, acceptance testing and comparative measurements between devices.
- R&D engineers and optical designers: quantify eye‑box, FOV, retinal illuminance and effective angular resolution early in design iterations.
- Regulatory and safety engineers: assess measurement procedures and results for safety compliance and harmonized documentation.
- Certification bodies: use the standard methods to support product claims and interoperability testing.
Benefits include repeatable performance metrics, comparable product specifications, and a framework for assessing retinal imaging characteristics specific to Maxwellian‑view RS‑RDP systems.
Related standards
- Other parts of the IEC 62906 series (Laser display devices) provide complementary guidance across laser display topics.
- The standard’s annexes offer practical models and context: Maxwellian view explanation, eyeball modelling for measurements, and comparisons of retinal illuminance with conventional displays.
Keywords: IEC 62906-5-5, laser displays, raster-scanning retina direct projection, optical measuring methods, eye-box, field of view, retinal illuminance, effective angular image resolution.