Technical Specifications of the OPC Facility
Measuring Performance Light Sources including
OLED and LED-Based Systems
In today’s product formats, LEDs are deployed in singular or in plural clusters. Some form factors deploy white LEDs or RGB (Red Green Blue) for colour mix. In all of these products, colour, light output and uniformity can change over varying periods of time, with many influences that can alter or degrade performance, including:
- • Thermal conditions inside the product
- • Ambient temperatures/humidity
- • Drive electronics
- • Behaviour of optics
- • Unsuitable reflectance products
- • Thermal management designs.
In order to measure efficiency of plasma/TFT/LCD/LEDs/OLEDs and LED based products more effectively, the metrology tools required are different from those conventionally used.
The Optical Performance Centre has the following measurement capabilities:
Light and Colour measurements:
- • Measure Spectra with no spectral gaps through the Ultraviolet (to 200nM) – Visible and IR wavelengths (to 2500nM) down to accuracy of 0.01 nm
- • Total luminous flux over angle (total light output and uniformity)
- • Photometric tests carried out in line with BS EN 13032-1
- • Spectro-radiometric measurement of light source at angle in 1°, 5° or 10° steps to produce 2D and 3D polar plots at stable 25°C (environmentally controlled)
- • Colour stability (colour change with respect to thermal or electronic drive conditions)
- • Phosphor degradation and performance loss
- • Fluoroscopy
- • Flash Photometry (also as a function of angle) at sub millisecond levels
- • Colour Rendering Index (CRI) to accuracy of 0.1%
- • Correlated Colour Temperature (CCT) to accuracy of 0.1K
- • Climatic and environmental stress (-40°c +180°c) over time, including 0-95% relative humidity
- • IES LM-63-02, Eulumdat and Radiant Source model files for lighting design software
Measuring capture and sensor products: Complex optical structures, filters, solar concentrators, cells
- • Energy exchange efficiency of active photonic surface area
- • Optical efficiency of complex filters and hardness coatings
- • Efficiency of solar concentrators, mirrors and reflectance panels
- • Systemic efficiency when coupled to energy conversion electronics, electronic management and super-capacitive cells
- • 50 frames per second
- • Thermal exchange efficiency of active surface area from cold start
- • Map the conductivity of connecting thermal materials
- • Efficiency of Heat-sinking over time
- • Accuracy to 0.1°c
Reflectometry (for various applications)
Reflectometry is the testing of surface reflectance/uniformity of components.
For instance, this may be used to ensure that road signs conform to various standards, including: BS EN 873, “Road traffic signs and internally illuminated bollards”; CIE 15.2, “Colourimetric”; BS 5499, “Safety signs, including fire safety signs”; CIE 74, “Road signs”; CIE 54.2, “Reflectometry- Definition and measurement”; BS EN 12899-1, “Fixed, vertical toad traffic signs”; and BS EN 12352, “Traffic control equipment- warning and safety devices”.
Environmental and Stress testing (for various applications)
- • Climatic chambers can be cycled to place products under stress
- • Shaking chamber – which can provide shudder and percussive effects to a products
- • Climatic and environmental stress (-40° to +180°) over time
- • Drop slide – check optical products breaking strains to their standards
High Speed Imaging Camera
The high speed camera operates at 60,000 frames per second (FPS) with an intense light source, <3,800 FPS for natural visible light conditions and has, for instance, been extremely useful in imaging the output of engine injectors.
Systemic test approach (power and harmonics)
Photometric output test measuring the full system including power management, power conversion, power supplies, drivers, dimmers, etc., with respect to indications from the power harmonics analyser.