BS IEC 62906‑5‑4 is a part of an international standard that discusses laser display devices. It can be your best guide in measuring the colour speckle used in laser devices.
BS IEC 62906‑5‑4 specifies the fundamental colour speckle distribution in CIE colour systems and the measuring methods of the colour speckle of laser display devices (LDDs).
BS IEC 62906‑5‑4 gives technical specifications such as fundamental terms related to color speckle distribution and spatial variation, definitions, theory of color speckle, calculation methods of colour speckle, direct measuring methods of colour speckle, measuring methods related to spatial variation, etc. for the evaluation of color speckle.
BS IEC 62906‑5‑4 on Laser display devices is useful for:
The colour speckle of laser display devices (LDDs) may be coined as speckle when the light source is multi-coloured. It is recognized as fine colour patterns different from the colour intended to be displayed. Laser speckle helps in producing the random interference pattern when coherent light scatters from a random medium and can be imaged onto a detector.
The colour speckle of the laser display devices using coherent or partially coherent light sources emitting at different wavelengths is created by spatially superposing their monochromatic speckle patterns. Particularly for hybrid laser display devices, the colour speckle is also created by superposing such monochromatic speckle patterns on speckle-less colour patterns generated by incoherent light sources.
Therefore, BS IEC 62906‑5‑4 describes a theory of colour speckle and specifies the colour speckle creation mechanism along with the examples of colour speckle distribution in CIE 1976 chromaticity diagram and the evaluation indices.
With the help of BS IEC 62906‑5‑4, you can calculate the colour speckle which is useful in determining the physical parameters of the imaging plane. These physical parameters obtained on the imaging plane are as follows:
BS IEC 62906‑5‑4 can be your best guide in measuring the colour speckle used in laser devices. These measuring methods also help in measuring the spatial variation at the points of the projection plane (screen) which are included in laser display devices.
IEC 62906-5-4:2018