The world today is hard to imagine without displays. They are ever-present in our daily life in mobile phones, computer and television screens, digital signage in- and outdoors, as well as the increasing number of displays in vehicles and domestic appliances.

The development and production of high-quality displays is very demanding and calls for high investments due the need of latest technology know-how, long-term developments and large and expensive production facilities. In the development phase and also later in the production phase a fast and reliable assessment of display characteristics and quality is key. This is also essential for companies who use displays in their products, like for example car manufacturers, because they also need to accurately evaluate or adjust displays quickly and reliable.

To address those needs Admesy offers industrial proven display measurement solutions. This article gives a brief overview about the history of the company and then outlines how Admesy measurement devices satisfy current and future display measurement needs.

Steadily inventing and growing

Admesy was founded in 2006 by former Philips employees from the Philips Mobile Display Department that produced displays for phones. The goal of Admesy then was and still is to offer measurement solutions which are accurate, easy to integrate and at the same time robust in a 24/7 production environment.

Using the available knowledge and expertise, the new company quickly developed into a global niche player. The company now offers stable, reliable and accurate measurement devices for displays, lighting and general spectroscopy applications. The current product portfolio includes spectroradiometers, colorimeters, 2D imaging colorimeters and light and flicker meters, as well as measurement solutions for specific applications, for example CIE 127 compliant LED measurements or fluorescence and transmission evaluation.

Customers world-wide are served from Admesy’s headquarters near Maastricht in the Netherlands. To assist the company’s many Asian customers an office in Seoul, Korea was opened in 2013, followed by an office in Shenzhen, China in 2017. Since 2022 an office in Tokyo was added to directly support Admesy’s Japanese customers.

Complete measurement solutions for displays

In the development phase of displays, during production or when integrating displays the need for repeatable and fast assessment of the image quality of a display arises. Because there is no universal metric to describe the image quality with a single number one will typically combine a series of measurements and metrics.
One crucial display characteristic is the uniformity. Most of the time the best practical solution is using a 2D imaging colorimeter, which will allow to quickly determine the luminance and color uniformity. The main advantage of an imaging solution is the high spatial resolution and the speed of the measurements. Admesy offers custom and off-the shelf imaging systems.

Other important characteristics are the minimum and maximum luminance, which directly determine the contrast ratio. Also important is the color accuracy across the complete driving range, for most displays for the three channels red, green and blue. A representative number of colors needs to be measured from low driving levels of the single and combined channels up to white when all channels are at their maximum. This data will be used to color-correct a display, set the correct target gamma curve and also allows to describe the color gamut – the range of possible colors which can be displayed. Finally time resolved measurements will describe the response time and help to assure that a display is flicker free as well.

Those measurements are typically carried out for a single spot on the display, when no spatial information is needed. There are three different device types available, each having specific strengths and therefore different use cases. The Admesy Prometheus series includes all three device types, namely spectroradiometers, colorimeters and light and flicker meters.

For highest demands regarding absolute accuracy and for all applications where the spectral information is beneficial, the Prometheus Viewfinder Spectrometer is a perfect solution. It utilizes a high-end cooled CCD detector for low noise and high dynamic range and a unique internal wavelength monitoring. Highest accuracy for your spectral and colorimetric readings from low to high luminance are the result. The electronic viewfinder and a motorized focus support an easy and repeatable setup as well the option to document the measurement conditions by saving an image of the measurement area. Last but not least the integrated flicker measurement option completes this versatile all-in-one display measurement solution.

Prometheus Viewfinder Spectrometer is available with an acceptance angle of 1.2° or a measurement spot of about 1 mm. Typical applications are R&D or process control and quality management, for instance in the production of high-end displays like for medical applications. Another typical use is as a reference device, for example to calibrate colorimeters to a specific device under test (DUT).

The next device category are colorimeters. They use filters modelled after the color matching functions of the CIE 1931 2° standard observer, describing the human vision. As a result colorimeters will directly deliver CIE XYZ tristimulus values, which can be transferred to xy, u’v’ and other values as needed. The quality of the filters will determine the accuracy of the color measurement for displays with different spectral characteristics. The Admesy Prometheus colorimeters excel here by using precise custom filters which are produced in-house.

The advantage of using a colorimeter over a spectroradiometer is the even higher measurement speed, because the light will be split up to three channels (XYZ) only. This in comparison to a spectroradiometer where the light is dispersed and smaller fractions of light will be spread out on a high number of channels on the sensor.
Admesy offers colorimeters for very small measurement spots, starting from 2.1 mm, for example for camera-under-display measurements. The range goes up to 27 mm measurement spot size. The 27 mm Prometheus colorimeter is not only very accurate for lowest light levels, but also the fastest display colorimeter currently on the market. All Prometheus colorimeters have the capability to measure flicker with 3 125 samples per second.

For all applications where an extreme high sample rate is needed the Admesy luminance and flicker meter completes the Prometheus series. It also offers in-house produced Y-filters, for a perfect match to the V(λ) luminous efficiency function. The main benefit of the Admesy luminance and flicker meter is the almost unbelievable high sampling rate of 800 000 samples per second. This covers the needs for even the most demanding time-resolved luminance measurements.

Always an eye on the future of displays

LCDs have been the staple of the display industry for many years and are still widely used for TVs, laptop and computer screens or in embedded solutions. But at the same time the market share for OLED has steadily been growing and OLED is now the major technology for mobile phones. The next technology likely having a huge impact on the display industry will be Micro-LED. When looking at different display applications we can expect to see a significant growth in micro displays, for example used in XR applications. The display market keeps moving and is in a constant change and adaption over the years.

It is obvious that the continues development of display technologies and new or improved display applications also need to be reflected in the used display measurement devices. Therefore Admesy is continuously evolving the current measurement solutions as well as developing new solutions. This takes place in the headquarter in the Netherlands, but is often stimulated and done in close cooperation with large display and electronics manufacturers. A major benefit of working with Admesy is how fast new or customized products can be developed. The in-house production of the main parts allows to quickly create working samples of new measurement devices. After the design and approval process those one-off prototypes can be scaled up to large production runs due the largely automated and streamlined production methods — almost in a snap.

As a result of the growth of Admesy and to provide the resources to satisfy the customer needs in the future Admesy has invested heavily in R&D and production capabilities. In 2021 Admesy quadrupled the floorspace with a large new building, expanding not only R&D, but also the production facilities with additional clean rooms and also more space for logistics and offices.

Expect to see exciting new measurement solutions from Admesy and keep your eyes open on the future of displays and display measurement technology.