OLED Displays

Characterization of displays and luminous surfaces

Displays and luminous surfaces (illuminated signs, backlit keyboards, pictograms, luminous buttons, phosphorescent markings, signage…) possess measurable photometric and colorimetric characteristics.

The ability to characterize these luminous devices by means of the appropriate equipment allows objective quantification of their visual performance and verification of their regulatory compliance.

PISEO has first-rate skills and equipment to provide objective, impartial and quality measurement results for your screens and luminous devices. PISEO is able to offer you luminance measurements and 2D luminance maps, spectral and colorimetric distribution measurements, as well as flicker measurements, carried out in accordance with international standards.

Luminance and 2D luminance maps

Luminance, which corresponds to the light intensity per unit area expressed in cd / m², is one of the key characteristics of the visual experience when looking at a light source.

The higher the luminance and the contrast with the ambient light, the more likely the light source will produce glare and, therefore, visual discomfort. This is particularly true with LED lighting devices that produce high levels of luminance (> 5000 cd / m²), especially where LEDs with a very small light emitting surface are directly visible.

In the case of displays (TFT, OLED) and other devices such as backlit keyboards, human-machine interfaces (HMI), pictograms, reflective strips, light buttons, pictograms …, in addition to the point luminance, PISEO will also MEASURE in average luminance, luminance uniformity and contrast over the entire light surface.

In this case, the characterization of the luminance in 2D by means of an imaging photometer will be particularly suitable for effectively and reliably measuring the performance of any light surface.

It allows, in particular, all measurements of the performance characteristics to be carried out in accordance with international norms and standards such as IDMS, ISO 9241-305, ISO 3864-4, EN 1838 …

This equipment, which has different objectives and particularly sophisticated analysis software, allows us to quickly and reliably evaluate your lighting devices and provide you with accurate results containing the following parameters:

  • Spot luminance
  • Average luminance per defined area
  • Uniformity accross the area
  • Contrast between different areas
  • Dead pixels

Measuring equipment

  • Westboro Photonics PF 501 A 5MP photometer, dynamic range from 0.01cd / m² up to 100 Mcd / m²
  • 50mm, wide-angle, macro lenses
  • Photometrica processing and analysis software

Spectral distribution and colorimetric measurements

The spectral and colorimetric distribution measurements of displays and luminous surfaces are carried out by means of a spectroradiometer and a remote probe which is applied to the surface to be characterized.

The use of a spectroradiometer allows the measurement of the entire emitted light spectrum and the precise calculation of the colorimetric characteristics (color point).

Measuring equipment

  • Integrating spheres Instrument Systems 2m and GL Optik 50cm
  • Instrument Systems CAS 120 and 140CT spectroradiometer
  • Flicker measurements on display

The flicker characterizes the flickering of displays form any light source. At specificfrequencies, it can be seen by the human eye. This phenomenon depends on the electronic design and a discriminating characteristic of the quality of the system.

Using the appropriate equipment, PISEO offer flicker measurements on screens in accordance with international standards IDMS, ISO 9241-305, IEC 62288

Measuring equipment

  • Admesy Asteria Flickermeter