Overview
IEC 61947-2:2001 - Electronic projection: Measurement and documentation of key performance criteria - Part 2: Variable resolution projectors defines standardized methods to measure and document the visible performance of raster-scanned, variable-resolution projectors (for example CRT and laser-based projectors). This standard codifies how to report key parameters such as light output, contrast, resolution and colour so that manufacturers, test laboratories, integrators and purchasers can compare and specify products consistently. The bilingual edition (2013-02) corresponds to the original English edition published in 2001.
Key topics and technical requirements
The standard covers a comprehensive set of measurement topics and documentation requirements, including:
- Light output and luminance: measurement methods, full-black level, specifications for devices with or without integral screens, and uniformity metrics.
- Contrast and blanking: procedures for contrast ratio and blanking/blanking-time measurement.
- Variable-resolution characteristics: visual resolution measurement (horizontal and vertical), procedures, and alternative methods (Annex G: NIDL grille contrast method).
- Video frequency response: frequency response specification relevant to raster-scanned signals.
- Colour measurements: chromaticity and colour uniformity assessment and a figure-of-merit for colour gamut (informative Annex J).
- Geometric and optical parameters: viewing-angle (half-gain) for integral screens, keystone correction, range of focus and image size.
- Signal compatibility and timing: input signal format compatibility, sync/blanking timing, and recommended practices for sync hierarchy and DC restoration.
- Operational characteristics: response time, light source specification, audio characteristics, noise (sound level), power consumption, weight and dimensions.
- Test infrastructure and guidance: normative test patterns, pattern generator specs (Annex B), a complete sample specification (Annex D), and guidance on measurement errors and photometer precision (Annexes C, F, H, I).
Practical applications
IEC 61947-2 is intended for:
- Manufacturers documenting product performance for datasheets and marketing.
- Independent test laboratories conducting reproducible projector performance tests.
- Procurement and specification writers creating unambiguous equipment requirements for corporate, educational or government AV installs.
- AV integrators and system designers evaluating projector suitability for specific text/graphics-centric applications.
The standard is focused on projector measurement for computer-generated raster graphics and text; it is not intended to set design goals for manufacturers nor to fully cover fixed-resolution matrix displays (see IEC 61947-1).
Related standards
- IEC 61947-1 - Part 1: Fixed resolution projectors (related scope)
- IEC 60050(845) - IEV Lighting vocabulary
- ISO 3741 and ISO 7779 - Acoustic measurement references used for noise/sound level tests
Keywords: IEC 61947-2, electronic projection, variable resolution projectors, CRT projectors, laser projectors, projector measurement, resolution measurement, luminance, contrast, projector specifications.
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